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Centralia GENERAL SEWER FACILITY PLAN 2019 UPDATE
FINAL City of Centralia General Sewer/ Facility Plan Prepared for City of Centralia December 2019 1100 112th Avenue NE, Suite 500 Bellevue, WA 98004 BI1212191438SEA ES-1 Executive Summary Purpose of the General Sewer/Facility Plan The City of Centralia’s (City’s) wastewater system collects and treats wastewater effluent to state and federal requirements. The system consists of a network of mains, trunks, force mains, and pump stations that transport collected sewage to the City's wastewater treatment plant (WWTP). The WWTP located on Goodrich Road provides primary and secondary treatment for the City service area and North Port District. Besides treating the final effluent that discharges into the Chehalis River after being disinfected with ultraviolet (UV) light, the wastewater treatment facility also produces a Class A biosolids product using aerated static pile composting (with lime stabilization and heat pasteurization as a backup) that is safe for public use. The City’s wastewater system requires an ongoing capital improvement program to replace old components and make improvements to meet federal and state laws. The primary purpose of this General Sewer/Facility Plan is to identify and schedule sewer collection and treatment system improvements that correct existing deficiencies, plan for improvements to accommodate expansion as growth occurs, and provide a safe and reliable wastewater system for current and future customers. This General Sewer/Facility Plan will serve as the planning document for the City's sewer service for the next 20 years. It will be reviewed and approved by Washington State Department of Ecology (Ecology). Summary of Key Elements Sewer Service Area The service area where the City currently provides sewer service, or is planning to provide service in the future, is divided into 29 sewer drainage basins. Outside the service area boundary, Lewis County is responsible for all sewer service, including onsite disposal systems such as septic tanks. The sewer system consists of a treatment plant, 25 pump stations, and approximately 70 miles of gravity sewer piping and 19 miles of force mains. A summary of the sewer system characteristics is provided in Table ES-1. The gravity pipelines, summarized in Table ES-2, range in diameter from 6 inches to 26 inches. Approximately half of the gravity sewer pipe is 8-inch-diameter. Table ES-1. Sewer System Characteristics Description Data Population (City, 2015) 16,790 Total connections (2015) 6,488 Number of persons per household 2.4 Average gallons per capita per day (2011-2012; 2014-2015) 126 Average daily flow (2011-2012; 2014-2015) 1.91 mgd Number of pump stations 25 Total length of gravity sewer main ~ 70 miles Total length of force mains ~ 19 miles Notes: ~ = approximately mgd = million gallon(s) per day EXECUTIVE SUMMARY ES-2 BI1212191438SEA Table ES-2. Gravity Sewer Inventory Diameter (inches) Concrete (feet) Asbestos Cement (feet) Polyvinyl Chloride (feet) HDPE (feet) Vitrified Clay (feet) Ductile Iron (feet) 6 1,962 178 75 8 87,986 12,257 139,443 1,483 25,614 712 10 6,392 2,819 32,585 529 2,572 12 2,319 16,478 337 14 1,561 12 15 12,531 16 850 18 516 6,451 21 5,390 24 1,209 4,924 26 752 Total 100,384 15,254 217,877 3,614 30,084 724 Note: HDPE = high-density polyethylene Existing Facilities The City currently owns and maintains 25 wastewater pump stations. The characteristics of each pump station are presented in Table ES-3. Table ES-3. Pump Station Inventory No. Pump Station Type Initial Install Most Recent Rehab./ Pump Replacement No. of Pumps Pump Size (hp) Pump Capacity (gpm) 1 Borst Park W/D 1979 2009 2 30 1,100 2 Mt. Vista W/S 1982 2009 2 1.5 150 3 China Creek W/S 2004/11 2011 3 289.5 1,100-4,500 4 Eshom W/S 1982 2012 2 15 250 5 Galvin/Scheuber W/S 1982 2007 2 20 560 6 Industrial Dr. W/S 1978 2005 2 1 80 7 Jensen W/S 1981 2011 2 2.5 150 8 High Street W/S 1959 2010 2 5 200 9 Reynolds W/S 1983 2012 2 7.5 250 10 Marion P 1987 Motor #1 2012 2 3 100 11 State W/S 1985 2004/2009 2 1.5 80 12 Salzer W/S 1992 2001 2 7.5 115 13 Floral W/D 1970 1998 2 7.5 350 EXECUTIVE SUMMARY BI1212191438SEA ES-3 Table ES-3. Pump Station Inventory No. Pump Station Type Initial Install Most Recent Rehab./ Pump Replacement No. of Pumps Pump Size (hp) Pump Capacity (gpm) 14 Ace Auto (Gold #2) W/S 1970 2016 2 3 140 15 Fairgrounds (Gold #1) W/S 1970 2012 2 5 120 16 South Tower W/S 1978 2010 2 1.5 80 17 Van Buren W/S 1953 2008 2 3 150 18 Jefferson W/D 1962 2008 2 15 640 19 Long Road W/S 1987 2011 2 7.5 150 20 W. Mellen W/S 1970 2012 2 10 285 21 Military W/S 1970 2010 2 7.5 100 22 Scammon Creek W/S 1987 2010 2 7.5 200 23 Highland Park W/S 1994 2007 2 5 150 24 North Tower W/S 1999 2012 2 7.5 250 25 North Port W/S 2007 original 2 7.5 300 Notes: hp = horsepower gpm = gallons per minute N/A = not applicable No. = number P = package pump station Rehab. = rehabilitation W/D = wet well and dry well W/S = wet well, submersible pump Land Use The study area boundaries for this General Sewer/Facility Plan encompass land within the City's Urban Growth Area (UGA), as described in the Centralia Comprehensive Plan (City of Centralia, 2017). Over the last several years, several development areas were proposed and were reviewed for sewer availability and the improvements required to serve these areas. The study areas included the following: • Ford’s Prairie • Cook’s Hill • Waunch Prairie/Davis Hill • Widgeon Hill • Former City Golf Course The land uses for these five study areas are described in Chapter 2. Flows The total influent flow to the WWTP is made up of untreated residential and light industrial flow. The wastewater generated from the collection system is pumped to the WWTP by the China Creek Pump Station and the North Port Pump Station. The City’s existing collection system flows were estimated using the WWTP discharge monitoring reports for the 2011 through 2015 period. Table ES-4 presents the average annual flow per year based on the sewered population. The 2015 average annual wastewater flow was 1.94 mgd. EXECUTIVE SUMMARY ES-4 BI1212191438SEA Table ES-4. Existing Average Annual Flow Rates and Flow per Capita Year Average Annual Flow (mgd) Sewered Population Average Day Flow (gpcd) 2011 1.86 14,060 132 2012 2.15 15,570 138 2013 1.52 15,570 98 2014 1.69 15,570 109 2015 1.94 15,570 124 Averagea 126 a 2013 flow not included in average, because it is very low and is considered an outlier. Note: gpcd = gallon(s) per capita per day Peaking Factors A peaking factor is the ratio of a high flow, such as maximum day flow, to the average annual flow (AAF). Future sewer system flow rates are projected based on existing flow rates and are used to analyze how well the existing system is expected to perform in the future, indicating what improvements are needed to maintain or improve system function. Current peaking factors for the existing system are applied to those estimated future flow rates to establish projected peak flow scenarios for the system. Table ES-5 shows the existing flow rates and peaking factors as measured at the City’s WWTP from 2011 to 2015. Table ES-5. Summary of Existing Flows and Peaking Factors Year Flow Scenario Flow (mgd) Peaking Factor (by AAF) 2011 Average Annual 1.86 1.0 Maximum Month 3.82 2.1 Maximum Day 6.40 3.4 Peak Hour 6.47 3.5 2012 Average Annual 2.15 1.0 Maximum Month 4.47 2.1 Maximum Day 6.69 3.1 Peak Hour 7.35 3.4 2013 Average Annual 1.52 1.0 Maximum Month 4.20 2.8 Maximum Day 4.34 2.9 Peak Hour 5.11 3.4 2014 Average Annual 1.69 1.0 Maximum Month 3.99 2.4 Maximum Day 6.28 3.7 Peak Hour 6.86 4.1 2015 Average Annual 1.94 1.0 Maximum Month 5.82 3.0 Maximum Day 8.67 4.5 Peak Hour 8.99 4.6 EXECUTIVE SUMMARY BI1212191438SEA ES-5 Projected Flows Future flow rates were calculated for the 2020 (5-year) and 2035 (20-year) planning horizons. Population projections, as shown in Chapter 2, were used to calculate the projected flow rates by applying the estimated increases to the existing flow rates. Table ES-6 presents the projected flow rates for the City under average annual, maximum month, and maximum day conditions. Table ES-6. Projected Flow Rates Year Estimated Centralia Population Flow Scenario Flow (mgd) 2020 17,500 Average Annual 2.20 Maximum Month 5.40 Maximum Day 7.75 Peak Hour 8.28 2025 18,765 Average Annual 2.36 Maximum Month 5.79 Maximum Day 8.31 Peak Hour 8.88 2030 22,535 Average Annual 2.84 Maximum Month 6.96 Maximum Day 9.98 Peak Hour 10.67 2035 24,164 Average Annual 3.04 Maximum Month 7.46 Maximum Day 10.70 Peak Hour 11.44 The existing WWTP is currently rated for an average annual flow of 2.7 mgd, maximum month flow of 5.5 mgd, a maximum day flow of 8.6 mgd, and a peak hour flow of 9.3 mgd. The hydraulic capacity of the plant will be exceeded within the planning period, based on the projected flows presented in Table ES-6. Refer to Chapter 6 for more discussion regarding the WWTP capacity evaluation and plans for additional capacity. Infiltration and Inflow Infiltration and inflow (I/I) is the combination of groundwater and surface water that enters the sewer system. Infiltration is groundwater entering the sewer system through defects in the sewer system infrastructure, such as fractured pipes and leaking pipe joints. Inflow is surface water that enters the sewer system from sources such as roof and street drains and leaky manhole covers. Inflow is considered to be non-excessive if the average daily flow during periods of heavy rainfall does not exceed 275 gpcd. Between the beginning of 2011 and the end of 2015, peak flows exceeded this threshold about 4.7 percent of the time. The largest peak flow was 516 gpcd in December 2015. This storm event recorded 0.58 inch of precipitation on December 1, 2015, with a peak of 1.35 inches on December 8, 2015, followed by several days of record precipitation for the remaining days of December. The WWTP influent flow does respond to large precipitation events occurring over a few days. The City has included an I/I study as part of their capital improvement plan so that the results can be confirmed and to locate the affected collection system areas to determine if there are any cost-effective sewer rehabilitation measures to remove excessive inflow. EXECUTIVE SUMMARY ES-6 BI1212191438SEA Between the beginning of 2011 and the end of 2015, there were three dry weather flow events during suspected high groundwater conditions. Two of these events (May 2013 and April 2014) did not have excessive infiltration, having average daily dry weather flows of 81 gpcd and 114 gpcd, respectively. The only event that had excessive infiltration occurred in late April of 2015 and had an average daily dry weather flow of 131 gpcd. These numbers indicate that the system does not experience excessive infiltration. Section 3.1.5 provides more information on I/I. Existing Loads Table ES-7 presents the total and per capita WWTP loading data for 2015, which is the first full year of data after influent sampling improvements. Based on a sewered population of 15,570, the plant had an annual average 5-day biochemical oxygen demand (BOD5) loading of 0.177 pound per capita per day (ppcd) and a total suspended solids (TSS) loading of 0.207 ppcd. The BOD5 value is less than Ecology’s criterion of 0.2 ppcd (Ecology, 2008). As shown in Table ES-7, the 2015 maximum month BOD5 load was 3,776 pounds per day (ppd) and the maximum month TSS load was 3,973 ppd. Based on the City’s currently rated BOD5 loading capacity of 4,400 ppd and TSS loading capacity of 5,000 ppd, the plant is currently operating at 86 percent of its BOD5 capacity and 79 percent of its TSS capacity. Chapter 6 discusses the WWTP capacity evaluation and the results of that work to re-rate the plant. Table ES-7. 2015 Wastewater Treatment Plant Loading Constituent Flow Scenario Concentration (mg/L) Loading (ppd) Per Capita Loading (ppcd)a BOD5 Average Annual 230 2,764 0.177 Maximum Month 317 3,776 0.243 Maximum Day 349 5,508 0.354 TSS Average Annual 271 3,230 0.207 Maximum Month 366 3,973 0.255 Maximum Day 412 5,486 0.352 a Based on sewered population of 15,570. Note: mg/L = milligram(s) per liter Projected Loads Projected loads for the WWTP were calculated for 2020, 2025, 2030, and 2035 based on the existing per capita load for 2015 using the BOD5 and TSS per capita loadings shown in Table ES-7. The future loads are presented in Table ES-8. Table ES-8. Projected Loads Year Estimated Centralia Population Flow Scenario Projected BOD5 Loading (ppd) Projected TSS Loading (ppd) 2020 17,500 Average Annual 3,106 3,630 Maximum Month 4,244 4,465 Maximum Day 6,191 6,167 2025 18,765 Average Annual 3,331 3,893 Maximum Month 4,551 4,788 Maximum Day 6,638 6,612 2030 22,535 Average Annual 4,000 4,675 Maximum Month 5,465 5,750 Maximum Day 7,972 7,941 EXECUTIVE SUMMARY BI1212191438SEA ES-7 Table ES-8. Projected Loads Year Estimated Centralia Population Flow Scenario Projected BOD5 Loading (ppd) Projected TSS Loading (ppd) 2035 24,164 Average Annual 4,289 5,013 Maximum Month 5,860 6,165 Maximum Day 8,548 8,515 Wastewater Treatment Evaluation The Centralia WWTP was completed in March 2004 and includes screening, grit removal, activated sludge aeration basins, secondary clarifiers, and UV disinfection prior to discharge to the Chehalis River through a multi-port diffuser at river mile 61.25. Solids processing includes belt filter press dewatering of activated sludge solids and aerated static pile composting. The City also has the ability to use lime pasteurization as a backup solids processing alternative. Influent sewage is pumped to the WWTP by either the China Creek Pump Station or the North Port Pump Station. Both pump stations use twin force mains of different sizes to maintain minimum velocity over the wide range of flows. Magnetic flow meters measure each of the incoming flows at the headworks. Potential Future Treatment Requirements Future regulatory requirements may include advanced treatment to address increasingly stringent river discharge criteria for nutrients. The nutrients evaluated for this General Sewer/Facility Plan were phosphorus and nitrogen. In addition to nutrients, effluent temperature is a concern as indicated by Ecology’s 2001 total maximum daily load for temperature in the Centralia segment of the Chehalis River. Plant Capacity A WWTP capacity evaluation was completed to determine the capacity of the plant to treat projected flows and loads, and prepare a plan to maintain adequate capacity. The capacity of each treatment process including the headworks screens, aeration basins and secondary clarifiers, UV disinfection system, effluent pumps, and solids handling was reviewed and compared to projected flows and loads. Table ES-9 presents the 2015 plant influent values, the permitted capacity, and projected 2035 influent flows and loads. For 2015, the plant was at 86 percent of the maximum month BOD loading capacity and 106 percent of the maximum month flow capacity. Table ES-9. Capacity Summary Parameter 2015 Base Year NPDES Permit Capacity 2015 % of Capacity 2035 Projected Influent Value Maximum Month BOD5 (ppd) 3,776 4,400 86 5,860 Maximum Month TSS (ppd) 3,973 5,000a 79 6,165 Maximum Month Flow (mgd) 5.82 5.5 106 7.46 Maximum Day Flow (mgd) 8.67 8.6 101 10.70 Peak hour/instantaneous peak flow (mgd) 9.1 9.3 98 11.44 a As approved in the 2014 General Sewer Plan Update Figure ES-1 shows a summary of the process capacity for each treatment process. The current plant process capacity is 5.5 mgd, as limited by the secondary treatment process. The hydraulic capacity (peak hour) is 9.3 mgd, as limited by the secondary clarifiers. EXECUTIVE SUMMARY ES-8 BI1212191438SEA Figures ES-2 and ES-3 show projected flows and loadings along with the revised plant capacity. As shown, in order to accommodate future growth, improvements will be required to expand the capacity of the WWTP. If the population increases as described in Chapter 2, the WWTP hydraulic capacity will be exceeded in 2024 and the plant loading will be exceeded in 2026. The City will closely monitor influent flow and loading on a yearly basis to verify influent assumptions presented in this General Sewer/Facility Plan. Note: Dewatering capacity is based on 5 days per week, 8 hours per day operation. Figure ES-1. Process Capacity Summary 5.5 5.5 10 13.9 19.9 10 10 10 9.3 15 11.3 0 246810 121416 1820 Plant Flow, MGDAverage Maximum Month Peak Hour EXECUTIVE SUMMARY BI1212191438SEA ES-9 Figure ES-2. Projected Loading Versus Proposed Capacity, Maximum Month 3000 3500 4000 4500 5000 5500 6000 Maximum Month Loading, ppdYearProjected BOD Loading, ppd Projected TSS Loading, ppd BOD Capacity, ppd TSS Capacity, ppd EXECUTIVE SUMMARY ES-10 BI1212191438SEA Figure ES-3. Projected Flow Versus Proposed Capacity, Maximum Month Wastewater Treatment Plant Alternatives WWTP upgrades are needed by 2024 to increase plant capacity and meet the effluent limits defined in the City’s current NPDES permit. Three alternatives were considered to provide the additional process capacity required: • Alternative 1 – Third Aeration Basin and Secondary Clarifier • Alternative 2 – Primary Clarifiers and Anaerobic Digester • Alternative 3 – Membrane Bioreactor The ability of each alternative to meet potential future nutrient removal requirements was also considered. Alternative 1 has the lowest capital and life-cycle cost (see Chapter 6) and meets WWTP capacity needs for the planning period. Therefore, Alternative 1 is the selected alternative. The alternatives considered address longer-term plant capacity needs. The City also identified desired improvements to benefit operations in the near-term. Therefore, two phases of plant upgrades are planned: Phase I to add operational flexibility for the near term, and Phase II to address capacity needs for the longer term. Phase I includes the addition of mixed-liquor recirculation pumps in the aeration basins and dedicated waste activated sludge (WAS) storage tanks to increase operational flexibility and optimize the existing WWTP capacity. Phase I upgrades will include the following: • Installing mixed-liquor recirculation (MLR) pumps in the existing aeration basins to pump mixed liquor from the end of the aeration basins to the beginning (anoxic zone) of the aeration basins. 4 5 6 7 8 9 10 11 Plant Flow, mgdYear Projected Max Month Flow, mgd Max Month Flow Capacity, mgd Projected Peak Day Flow, mgd Peak Day Flow Capacity, mgd EXECUTIVE SUMMARY BI1212191438SEA ES-11 • Improving solids handling by installing waste activated sludge (WAS) storage tanks. WAS will be pumped from the secondary clarifiers to the WAS tanks for storage, then pumped from storage to the belt filter press (BFP) for dewatering. • Installing new positive-displacement blowers in the existing blower building to provide aeration for the WAS storage tanks. • Expanding the existing blower building to provide a second electrical room (electrical annex) to allow for expansion of the existing motor control center (MCC) and remote input/output racks to supply power and control to the Phase I equipment. Refer to Chapter 6 for the design summaries for MLR, WAS storage tanks, and the WAS blowers. Sizing of the electrical annex is also discussed. Phase II improvements include a third aeration basin, a third secondary clarifier, a third WAS storage tank, a third headworks screen, and a second grit removal system. The existing blower building also would be expanded. If further nitrogen removal is desired or required, additional upgrades will be needed. The existing aeration basins were sized and constructed with sufficient capacity so that a swing zone could be added in the future as needed. A baffle wall can be constructed in the first one-third of the aerobic zone to provide a swing zone after the anoxic zone. Submersible mixers would be added to these new swing zones. The swing zone helps improve the operational flexibility in treating influent TKN/ammonia loading and would be operated differently depending on the season. The existing diffusers may be adequate to supply the required air demand in the aerobic zone; this will be verified with additional influent data. Table ES-11 presents a summary of the secondary process improvements required and design criteria, including the associated dimensions and capacity, for the Phase II improvements described in Chapter 6. Table ES-11. Summary of Phase II Improvements Design Criteria Component Quantity (new units) Criteria and Sizing Value Mechanical Screen 1 5 MG Vortex Grit Removal System 1 10 MG Grit Pump 1 250 gpm Aeration basin 1 Volume 0.9 MG Volume unaerated 14 percent Sidewater depth 15 feet Length 205 feet Width 39 feet Hydraulic retention time (max month) 7.5 hours Solids retention time (max month)a 10 days Mixed liquor suspended solids 2,900 mg/L Minimum bioreactor temperatureb 11.5 degrees Celsius Aeration equipment Multistage centrifugal aeration basin blower 1 3,200 scfm Fine bubble diffusers 459 2.0 scfm each Dissolved oxygen concentration 2.0 mg/L EXECUTIVE SUMMARY ES-12 BI1212191438SEA Table ES-11. Summary of Phase II Improvements Design Criteria Component Quantity (new units) Criteria and Sizing Value Mixed-liquor recirculation pumps 1 2,000 gpm each Secondary Clarifier (circular) 1 Diameter 70 feet Sidewater depth 18 feet Maximum month overflow rate 715 gpd/sf Peak flow overflow rate 1,200 gpd/sf Maximum month solids loading rate 23.2 lb/sf/d Peak solids loading rate 41.5 lb/sf/d SVI (peak day design) 150 mL/g RAS ratio 48 percent WAS tank (each) 1 Volume 0.1 MG Sidewater depth 20 feet Length 26 feet Width 26 feet WAS tank mixers (each) 2 1 7.5 hp maximum Positive-displacement WAS blower (each) 1 540 scfm Blower building expansion 20 feet x 32 feet Ultraviolet Disinfection 1 channel Type Low pressure Design Flow 3.1 mgd TSS 30 mg/L UV Transmittance 65% Aeration basin mixers for swing zone (each)c 3 10 hp a The selected SRT provides a safety factor of 1.23 for what is required to nitrify the anticipated peak day TKN loading. This SRT correlates with the 10.8 days used for the 2002 design. b Equal to the minimum 7-day average influent temperature from 2008 to 2016. According to 2014 and 2015 data, the maximum week loading is expected to occur in the wet weather season when the influent temperature is low. Process performance at minimum 30-day temperature (12 degrees Celsius) and minimum day temperature (10.7 degrees Celsius) was also evaluated to test sensitivity of the proposed design to wet weather temperature fluctuations. The proposed design was found to provide sufficient capacity to meet process performance requirements during minimum day wet weather temperatures. c Only required if TN less than 10 mg/L is required Notes: hp = horsepower scfm = standard cubic foot/feet per minute EXECUTIVE SUMMARY BI1212191438SEA ES-13 Operations and Maintenance The City’s Wastewater Department provides the resources and staff to perform system repairs, implementation of the standard operating procedures, and ongoing system maintenance. The City currently employs the equivalent of 13 full-time positions to oversee the operations and maintenance (O&M) of the collection system and WWTP. Table ES-12 presents a breakdown of the type and amount of staff allocated to different positions within the City’s Wastewater Department. Some positions represent less than one full-time position, because duties are shared among other positions and City departments. Table ES-12. Wastewater Department Operations and Maintenance Staff Position Full-time Equivalents Wastewater Treatment Plant Manager 0.5 Operators 3.5 Maintenance 0.5 Laboratory 1.0 Instrumentation and Electrical 0.5 Pretreatment 1.0 Farm 1.0 Total WWTP 8.0 Collection System Manager 0.5 Instrumentation and Electrical 0.5 Technicians 4 Total Collection System 5.0 The plant is staffed 5 days per week, 8 hours per day, by the plant manager, a process analyst, a lead operator, three operators, and an electrical/instrumentation technician. Collection system staff are responsible for the O&M of the collection system sewer mains and pump stations. The City’s 25 pump stations are inspected once per week. All pump stations have radio telemetry and are monitored continuously for alarms. Operations and Maintenance Programs Sewer Service The City has a sewer ordinance (Centralia Municipal Code 15.10) that describes domestic and high strength users, user charges, side sewer connections, damage to sewers, permit application, type, and fees, sewer construction and testing, prohibited discharges, violations and penalties, and schedule of charges. Fats, Oil, and Grease The City has a fats, oil, and grease (FOG) program including mandatory FOG pretreatment per the Centralia Municipal Code 15.10.280. One staff member is dedicated to the operation of this program, which requires that any customers serving or preparing food where grease may be introduced into the system must have pretreatment facilities to prevent discharge of FOG. EXECUTIVE SUMMARY ES-14 BI1212191438SEA Water Surface Elevation Monitoring This program consists of measuring water surface elevations at strategic manholes within the existing collection system. This program is one of two approaches the City employs to evaluate the wet weather system flows. This program is used to identify the extent of surcharging in the system and the variation in surcharging during the year. Flow Monitoring The City’s flow-monitoring efforts include monitoring dry and wet weather flow at selected locations to quantify I/I reduction efforts and recording flows at existing pump stations. Financial Capital Chapter 8 presents the financial analysis for the capital improvement projects identified in this plan, including estimated capital costs, O&M costs, and life-cycle costs. Project financing and user charges required to support the projects are also discussed. Class 5 capital cost estimates were prepared to the Association for the Advancement of Cost Engineering International standards for the projects identified in this plan. As defined by these standards, the expected accuracy range for a Class 5 estimate is a low of minus 30 percent and a high of plus 50 percent. Table ES-13 summarizes the projects identified in the sewer system evaluation and their estimated costs. Table ES-13. Proposed Sewer and Facility Plan Capital Projects ID Project Description Total Estimated Cost (2016 dollars) CC-1 China Creek Interceptor Stabilization Install riprap along Chehalis River to protect pipelines from erosion $1,750,000 CS-1 Centralia Station New sewer to serve Centralia Station development $3,880,000 M-1 Pump Station Maintenance Replacement of mechanical and electrical and concrete corrosion coatings $1,820,000 II-1 I/I Demonstration and Removal Projects Demonstrate technology, determine effectiveness and confirm costs of I/I removal technologies $2,700,000 WW-1 Phase 1 WWTP Improvements Design and construction of recirculation pumps and solids storage $5,840,000 WW-2 Solids Handling Upgrades Upgrade dewatered sludge conveyance, new belt filter press, and compost facility covers $1,630,000 WW-3 Headworks Screen Additional headworks screen $2,120,000 WW-4 PLC and MCC Upgrades Upgrade PLC and MCC equipment $500,000 WW-5 Phase 2 WWTP Improvements Design and construction of additional plant capacity $17,202,000 WW-6 Temperature Compliance Evaluation Update Review new temperature data, evaluate and select temperature mitigation $60,000 WW-7 Thermal Mitigation Needs Design and construct thermal mitigation alternative $1,240,000 ES-1 Pipeline Replacement Program Aging pipeline replacement program $5,220,000 ES-4 First Street Between G and F Streets Existing System Improvement $160,000 EXECUTIVE SUMMARY BI1212191438SEA ES-15 Table ES-13. Proposed Sewer and Facility Plan Capital Projects ID Project Description Total Estimated Cost (2016 dollars) F-1 Ford’s Prairie Interceptor Provide sewer to UGA $11,810,000 F-2 Area North of and Adjacent to Kuper Road Provide sewer to UGA $2,950,000 F-3 Private Drives Area Provide sewer to UGA $1,310,000 F-4 Trailer Park Area Provide sewer to UGA $1,270,000 F-5 Southeast Area Provide sewer to UGA $7,920,000 F-6 Industrial Area Provide sewer to UGA $1,040,000 F-7 Reynolds Avenue Area Provide sewer to UGA $2,540,000 F-9 Southwest Area Provide sewer to UGA $4,030,000 F-10 Gallagher Road Area Provide sewer to UGA $1,950,000 NS-7 Fords Prairie Residential Provide sewer to UGA $8,200,000 US-7 Fords Prairie Provide sewer to unsewered area within City limits $1,090,000 CH-1 Cook’s Hill Sewer Extension Provide sewer to UGA $14,520,000 CH-2 Cook’s Hill Pump Stations Provide sewer to UGA $1,030,000 NS-5 Cooks Hill Residential Provide sewer to UGA $7,450,000 NS-15 Graf Road Residential Provide sewer to UGA $4,660,000 US-2 South Cooks Hill Residential Provide sewer to unsewered area within City limits $80,000 NS-9 Kresky Residential I Commercial Provide sewer to UGA $2,120,000 US-3 East of Plummer Lake Provide sewer to unsewered area within City limits $670,000 W-1 Waunch Prairie Interceptor Provide sewer to UGA $3,310,000 W-2 North Pearl Street Interceptor Provide sewer to UGA $4,310,000 W-5 Dixon Road and Roanoke Street Area Provide sewer to UGA $1,990,000 W-6 Southeast Area Provide sewer to UGA $2,270,000 W-7 Oakview Avenue Area Provide sewer to UGA $2,130,000 W-8 Carson Street Area Provide sewer to UGA $6,030,000 W-9 Sawall and Lowery Area Provide sewer to UGA $3,140,000 WH-1 Widgeon Hill Sewer Extension Provide sewer to UGA $3,900,000 WH-2 Widgeon Hill Pump Station Provide sewer to UGA $1,040,000 US-4 Ham H/11 Provide sewer to unsewered area within City limits $9,660,000 NS-10 South Ham Hill Residential Provide sewer to UGA $3,000,000 Total $159,542,000 Capital Financing Plan Financing for the City’s wastewater capital program consists primarily of proceeds from long-term, fixed-rate sewer revenue bond sales; short-term variable rate borrowing; cash transfers from the EXECUTIVE SUMMARY ES-16 BI1212191438SEA operating fund; and low-interest loan programs administered by the State of Washington, such as State Water Pollution Control Revolving Loan Fund loans and Public Works Trust Fund loans. Ongoing system O&M programs (including pump station maintenance and I/I removal) is paid from the wastewater O&M budget and funded by rates. Projects driven by development, such as the Centralia Station, are assumed to be paid for by the developer. BI1212191438SEA iii Contents Executive Summary ....................................................................................................................... ES-1 Purpose of the General Sewer/Facility Plan ............................................................................... ES-1 Summary of Key Elements .......................................................................................................... ES-1 Sewer Service Area ........................................................................................................ ES-1 Existing Facilities ............................................................................................................ ES-2 Land Use ......................................................................................................................... ES-3 Flows .............................................................................................................................. ES-3 Peaking Factors .............................................................................................................. ES-4 Projected Flows .............................................................................................................. ES-5 Infiltration and Inflow .................................................................................................... ES-5 Existing Loads ................................................................................................................. ES-6 Projected Loads.............................................................................................................. ES-6 Wastewater Treatment Evaluation ................................................................................ ES-7 Operations and Maintenance ...................................................................................... ES-13 Operations and Maintenance Programs ...................................................................... ES-13 Financial ....................................................................................................................... ES-14 Acronyms and Abbreviations ............................................................................................................. xi 1. Introduction ....................................................................................................................... 1-1 1.1 Background ...................................................................................................................... 1-1 1.1.1 System Ownership and Management ................................................................ 1-1 1.1.2 Projects Completed Since the Previous Plan ...................................................... 1-1 1.1.3 Overview of Existing Systems ............................................................................. 1-2 1.2 Purpose ............................................................................................................................ 1-2 1.3 Regulatory Requirements ................................................................................................ 1-3 1.3.1 Growth Management Act ................................................................................... 1-3 1.3.2 Washington State Department of Ecology ......................................................... 1-3 1.3.3 Lewis County ....................................................................................................... 1-4 1.4 General Sewer/Facility Plan Organization ....................................................................... 1-4 1.5 Required Content ............................................................................................................. 1-4 2. Service Area and Vicinity Characteristics .............................................................................. 2-1 2.1 Sewer Service Area .......................................................................................................... 2-1 2.1.1 General History ................................................................................................... 2-1 2.1.2 Sewer Drainage Basins ........................................................................................ 2-1 2.1.3 Onsite Sewer Systems ......................................................................................... 2-5 2.1.4 Unsewered Areas ................................................................................................ 2-5 2.2 Existing Environment ....................................................................................................... 2-5 2.2.1 Topography, Geology, and Soils.......................................................................... 2-5 2.2.2 Climate ................................................................................................................ 2-6 2.2.3 Air Quality ........................................................................................................... 2-9 2.2.4 Water Resources ................................................................................................. 2-9 2.2.5 Cultural Resources ............................................................................................ 2-15 2.2.6 Endangered Species and Habitats or Threatened Species ............................... 2-15 2.2.7 Public Health ..................................................................................................... 2-16 2.3 Existing Water System ................................................................................................... 2-16 2.3.1 Sources of Supply .............................................................................................. 2-16 2.3.2 Water Treatment .............................................................................................. 2-16 CONTENTS iv BI1212191438SEA 2.3.3 Storage .............................................................................................................. 2-17 2.3.4 Distribution System........................................................................................... 2-17 2.4 Planning Considerations ................................................................................................ 2-19 2.4.1 Growth Management Act ................................................................................. 2-19 2.4.2 Lewis County ..................................................................................................... 2-20 2.4.3 City of Centralia ................................................................................................ 2-22 2.5 Land Use ......................................................................................................................... 2-23 2.5.1 Current Land Use and Zoning ........................................................................... 2-23 2.6 Population – Historical and Projected ........................................................................... 2-28 3. Flows and Loads .................................................................................................................. 3-1 3.1 Flows ................................................................................................................................ 3-1 3.1.1 Existing Base Sanitary Flows ............................................................................... 3-1 3.1.2 Peaking Factors ................................................................................................... 3-2 3.1.3 Industrial Sources ............................................................................................... 3-3 3.1.4 Contributing Jurisdictions ................................................................................... 3-4 3.1.5 Future Base Sanitary Flows ................................................................................. 3-4 3.1.6 Infiltration and Inflow ......................................................................................... 3-5 3.1.7 Water Conservation ............................................................................................ 3-7 3.2 Loads ................................................................................................................................ 3-8 3.2.1 Existing Loads ...................................................................................................... 3-8 3.2.2 Future Loads ....................................................................................................... 3-9 3.3 Wastewater Design Criteria ........................................................................................... 3-10 3.3.1 City of Centralia Design and Development Guidelines ..................................... 3-10 3.3.2 Criteria for Sewage Works Design .................................................................... 3-10 4. Existing System ................................................................................................................... 4-1 4.1 Collection System ............................................................................................................. 4-1 4.2 Pump Stations .................................................................................................................. 4-2 4.3 Force Mains ...................................................................................................................... 4-5 4.4 Flood Events and the Collection and Conveyance System .............................................. 4-5 4.5 Sewer Overflows .............................................................................................................. 4-6 4.6 Wastewater Treatment Plant .......................................................................................... 4-6 4.6.1 Liquids Treatment Processes .............................................................................. 4-6 4.6.2 Plant Bypass ...................................................................................................... 4-10 4.6.3 Other Facilities .................................................................................................. 4-10 5. Sewer Collection System Improvements .............................................................................. 5-1 5.1 Introduction ..................................................................................................................... 5-1 5.2 Collection System Evaluation ........................................................................................... 5-1 5.2.1 Existing Collection System and Flows .............................................................. 5-1 5.2.2 Surcharging of Existing Trunk Sewers .............................................................. 5-2 5.2.3 Projected Development Flows ......................................................................... 5-2 5.2.4 Proposed Development Areas ............................................................................ 5-6 5.3 Collection System Alternatives ........................................................................................ 5-7 5.3.1 China Creek Interceptor ...................................................................................... 5-7 5.3.2 Evaluation of Centralia Station Development .................................................... 5-8 5.4 Evaluation of Pump Stations and Force Mains .............................................................. 5-13 5.5 Pump Station Assessment and Prioritization ................................................................. 5-17 5.6 Infiltration and Inflow Alternatives ................................................................................ 5-18 5.6.1 I/I Reduction Projects to Comply with Ecology Administration Order ............. 5-18 5.6.2 Infiltration and Inflow Pilot Projects ................................................................. 5-19 CONTENTS BI1212191438SEA v 5.6.3 Feasibility Evaluation of the Cost of Increasing the Hydraulic Capacity of the WWTP to Address I/I......................................................................................... 5-19 5.7 Recommended Improvements ...................................................................................... 5-20 5.7.1 Existing Collection System Deficiencies ............................................................ 5-22 5.7.2 New Development Area Improvements ........................................................... 5-23 5.7.3 Collection System Recommendations .............................................................. 5-44 5.7.4 Pump Station Improvement Recommendations (C.I.P. M-1) ........................... 5-49 5.7.5 Inflow and Infiltration Project Recommendations ........................................... 5-50 5.8 Alternative Systems ....................................................................................................... 5-52 5.8.1 Septic Tank Effluent Pumping Sewer System ................................................... 5-52 5.8.2 Low-pressure Sewer System ............................................................................. 5-53 5.8.3 Vacuum Sewer System...................................................................................... 5-53 5.8.4 Summary ........................................................................................................... 5-54 5.9 Application of Alternative Sewer Systems to New Areas .............................................. 5-55 6. Treatment Plant Evaluation ................................................................................................. 6-1 6.1 Description of Discharge Standards ................................................................................. 6-1 6.1.1 Applicable Water Quality Standards ................................................................... 6-1 6.1.2 Required Effluent Quality ................................................................................... 6-2 6.1.3 Potential Future Treatment Requirements ........................................................ 6-3 6.2 Reasonable Potential Analysis ......................................................................................... 6-4 6.3 Plant Capacity .................................................................................................................. 6-5 6.3.1 Background ......................................................................................................... 6-5 6.3.2 Capacity Evaluation Results ................................................................................ 6-6 6.3.3 Capacity Summary .............................................................................................. 6-9 6.4 Alternatives Analysis ...................................................................................................... 6-13 6.4.1 Alternative 1 – Third Aeration Basin ................................................................. 6-14 6.4.2 Alternative 2 – Primary Clarifiers and Anaerobic Digester ............................... 6-14 6.4.3 Alternative 3 – Membrane Bioreactor .............................................................. 6-15 6.4.4 Alternative Comparison .................................................................................... 6-16 6.4.5 Selected Alternative .......................................................................................... 6-17 6.5 Recommended Wastewater Treatment Plant Upgrades .............................................. 6-17 6.5.1 Phase I (C.I.P. WW-1) ........................................................................................ 6-17 6.5.2 Phase II (C.I.P. WW-5) ....................................................................................... 6-20 6.5.3 Data Needs ........................................................................................................ 6-23 6.5.4 Site Layout ........................................................................................................ 6-23 6.5.5 Flow Diagram .................................................................................................... 6-23 6.5.6 Hydraulic Profile................................................................................................ 6-23 6.5.7 Biosolids Disposal Plan ...................................................................................... 6-24 6.5.8 Design Life and Adequacy of Existing Process .................................................. 6-24 6.5.9 Ability to Expand Treatment Plant .................................................................... 6-24 6.5.10 Staffing Needs ................................................................................................... 6-24 6.5.11 Future Environment without the Project ......................................................... 6-24 6.5.12 Recreation and Open Space .............................................................................. 6-24 6.6 Water Reclamation and Reuse ...................................................................................... 6-24 6.7 Other Potential Improvements ...................................................................................... 6-34 7. Operations and Maintenance .............................................................................................. 7-1 7.1 Staffing ............................................................................................................................. 7-1 7.2 Scheduled Operations and Maintenance Activities ......................................................... 7-1 7.2.1 Wastewater Treatment Plant ............................................................................. 7-1 7.2.2 Collection System................................................................................................ 7-2 CONTENTS vi BI1212191438SEA 7.2.3 Pump Station ...................................................................................................... 7-2 7.3 Programs .......................................................................................................................... 7-3 7.3.1 Sewer Service ...................................................................................................... 7-3 7.3.2 Fats, Oil, and Grease ........................................................................................... 7-3 7.3.3 Water Surface Elevation Monitoring .................................................................. 7-3 7.3.4 Flow Monitoring ................................................................................................. 7-4 7.4 Unscheduled Maintenance Activities .............................................................................. 7-4 7.5 Management System and Recordkeeping ....................................................................... 7-4 7.6 Improvements .................................................................................................................. 7-4 7.6.1 Equipment ........................................................................................................... 7-4 7.6.2 Flow Monitoring ................................................................................................. 7-5 7.6.3 Television Inspection and Cleaning..................................................................... 7-5 7.6.4 Smoke Testing ..................................................................................................... 7-6 7.6.5 Staffing ................................................................................................................ 7-6 8. Financial ............................................................................................................................. 8-1 8.1 Costs ................................................................................................................................. 8-1 8.1.1 Capital ................................................................................................................. 8-1 8.1.2 Life Cycle ............................................................................................................. 8-3 8.2 User Charges .................................................................................................................... 8-3 8.3 Funding Sources ............................................................................................................... 8-4 8.3.1 Conventional Revenue Bond Financing .............................................................. 8-4 8.3.2 Double-barreled Revenue Bonds ........................................................................ 8-6 8.3.3 Centennial Clean Water Fund - Design and Construction .................................. 8-6 8.3.4 State Revolving Fund for Water Pollution Control ............................................. 8-6 8.3.5 Public Works Trust Fund Construction Program ................................................ 8-6 8.3.6 Alternate Funding ............................................................................................... 8-6 8.4 Capital Financing Plan ...................................................................................................... 8-7 9. Implementation .................................................................................................................. 9-1 9.1 Plan Adoption .................................................................................................................. 9-1 9.2 Water Quality Management Plan .................................................................................... 9-1 9.3 State Environmental Policy Act ........................................................................................ 9-1 9.4 State Environmental Review Process .............................................................................. 9-1 9.5 Schedule ........................................................................................................................... 9-2 9.6 List of Required Permits ................................................................................................... 9-2 9.7 Public Involvement Process ............................................................................................. 9-2 9.8 Developer Extensions ...................................................................................................... 9-2 9.9 Construction Standards ................................................................................................... 9-3 10. References ........................................................................................................................ 10-1 CONTENTS BI1212191438SEA vii Appendixes A City of Centralia General Sewer/Facility Plan Crosswalk B Water System Facility Map C Industrial User Permits and Lewis County Interlocal Agreement D Infiltration and Inflow (I/I) Analysis and City Completed Projects to Address I/I E Existing Load Analysis F City of Centralia Sewer Collection System Mapping and Data (CD only) G Plant Design Data H City of Centralia National Pollutant Discharge Elimination System Waste Discharge Permit I Reasonable Potential Analysis J Aeration Blower Air Flow Data K Plant Capacity Analysis L City of Centralia Sewer Service Ordinance and Grinder Pump Agreement M Manhole Monitoring Form N SEPA and SERP Documents O City of Centralia Sanitary Sewer Design and Development Guidelines Tables ES-1 Sewer System Characteristics ..................................................................................................... ES-1 ES-2 Gravity Sewer Inventory ............................................................................................................. ES-2 ES-3 Pump Station Inventory .............................................................................................................. ES-2 ES-4 Existing Average Annual Flow Rates and Flow per Capita .......................................................... ES-4 ES-5 Summary of Existing Flows and Peaking Factors ........................................................................ ES-4 ES-6 Projected Flow Rates .................................................................................................................. ES-5 ES-7 2015 Wastewater Treatment Plant Loading ............................................................................... ES-6 ES-8 Projected Loads ........................................................................................................................... ES-6 ES-9 Capacity Summary ...................................................................................................................... ES-7 ES-11 Summary of Phase II Improvements Design Criteria ................................................................ ES-11 ES-12 Wastewater Department Operations and Maintenance Staff ................................................. ES-13 1-1 Projects Completed Since the Previous Plan ................................................................................ 1-2 1-2 Summary of Sewer System Data ................................................................................................... 1-2 2-1 Federal and State Status of Endangered and Threatened Species in Centralia ......................... 2-16 2-2 Existing Water Storage Facilities ................................................................................................. 2-17 2-3 Pressure Zones ............................................................................................................................ 2-17 2-4 Booster Pump Stations and Zone Pressure Tanks ...................................................................... 2-18 2-5 Water Distribution Pipe Inventory .............................................................................................. 2-19 2-6 Zoning Districts within the City’s UGA – 2006 ............................................................................ 2-23 2-7 Ford’s Prairie Land Use ............................................................................................................... 2-27 2-8 Waunch Prairie/Davis Hill Land Use ......................................................................................... 2-27 2-9 Population Growth of Centralia .................................................................................................. 2-28 2-10 Projected Population .................................................................................................................. 2-28 3-1 Existing Average Annual, Maximum Month, Maximum Day, and Dry Weather Flow Rates ........ 3-2 3-2 Summary of Existing Flows and Peaking Factors .......................................................................... 3-3 3-3 Existing Average Annual Flow Rates and Flow per Capita ............................................................ 3-4 3-4 Projected Flow Rates .................................................................................................................... 3-5 3-5 2015 WWTP Loading ..................................................................................................................... 3-8 3-6 Projected Loads ............................................................................................................................. 3-9 3-7 Design Criteria Summary ............................................................................................................ 3-10 4-1 Gravity Sewer Inventory ............................................................................................................... 4-1 CONTENTS viii BI1212191438SEA 4-2 Pump Station Inventory ................................................................................................................ 4-2 4-3 Force Main Inventory .................................................................................................................... 4-5 5-1 Projected Peak Flows within UGA ................................................................................................. 5-3 5-2 Projected Peak Flows in Unsewered Communities ...................................................................... 5-4 5-3 Evaluation of Potential New Flows on Sewer System Capacity (Peak Sewage Flow Only) .......... 5-4 5-4 China Creek Interceptor Alternatives, Estimated Project and Life Cycle Costs ............................ 5-8 5-5 Centralia Station Development Cost Estimates .......................................................................... 5-12 5-6 Historical Pump Run Time Records ............................................................................................. 5-13 5-7 Pump Station Capacity for Peak Dry Weather Sanitary Flows .................................................... 5-14 5-8 Force Main Analysis for Peak Dry Weather Sanitary Flows ........................................................ 5-15 5-9 Pump Station Wet Well Rim Elevations ...................................................................................... 5-16 5-10 Pump Station Improvement Priority .......................................................................................... 5-17 5-11 Estimated Expansion Cost to Accommodate Hydraulic Capacity Expansion Instead of I/I Reduction .................................................................................................................................... 5-20 5-12 Ford’s Prairie Sewer Extension Projects ..................................................................................... 5-23 5-13 Cook’s Hill Sewer Extension Projects .......................................................................................... 5-33 5-14 Waunch Prairie/Davis Hill Sewer Extension Projects .................................................................. 5-36 5-15 Widgeon Hill Sewer Extension Projects ...................................................................................... 5-43 5-16 Summary of Project Construction Costs for Centralia Station Sewer Improvements (Alternative 2) ............................................................................................................................. 5-48 5-17 Pump Station Improvement Project Costs.................................................................................. 5-50 5-18 Pilot I/I Project Rehabilitation/Replacement Technology Combinations ................................... 5-51 5 19 Alternative Sewer System Comparison....................................................................................... 5-54 6-1 Effluent Limitsa at Outfall No. 001 ................................................................................................ 6-2 6-2 Capacity Summary ........................................................................................................................ 6-6 6-3 Centralia WWTP Redundancy Requirements ............................................................................... 6-8 6-4 2035 Design Flows and Loads ..................................................................................................... 6-13 6-5 Alternative Comparison Matrix .................................................................................................. 6-16 6-6 Alternative Cost Comparison (2016 dollars) ............................................................................... 6-17 6-7 Design Summary for Anoxic Selector/MLR Sizing ....................................................................... 6-19 6-8 Waste Activated Sludge Tank Design Criteria Summary............................................................. 6-20 6-9 Summary of Phase II Improvements Design Criteria .................................................................. 6-22 6-10 Evaluation of Top Alternatives .................................................................................................... 6-33 7-1 Wastewater Department Operations and Maintenance Staff ..................................................... 7-1 8-1 Proposed Sewer and Facility Plan Capital Projects ....................................................................... 8-1 8-2 Monthly Sewer Rates, 2016 .......................................................................................................... 8-3 8-3 Proposed System Improvements (2016 Dollars) .......................................................................... 8-5 8-4 Wastewater Treatment Plant Improvements Costs (2016 dollars) .............................................. 8-6 Figures ES-1 Process Capacity Summary ......................................................................................................... ES-8 ES-2 Projected Loading Versus Proposed Capacity, Maximum Month .............................................. ES-9 ES-3 Projected Flow Versus Proposed Capacity, Maximum Month ................................................. ES-10 2-1 Vicinity Map .................................................................................................................................. 2-2 2-2 Sewer Service Area and Basins ..................................................................................................... 2-3 2-3 Topography Map ........................................................................................................................... 2-7 2-4 Chehalis River and Tributaries .................................................................................................... 2-11 2-5 Centralia Floodplain Map ............................................................................................................ 2-13 2-6 Centralia Wetlands Map ............................................................................................................. 2-14 2-7 New Sewer Study Area ............................................................................................................... 2-25 CONTENTS BI1212191438SEA ix 3-1 Cumulative Flow Frequency (2011 to 2015) ................................................................................. 3-7 4-1 Existing Sewers & Basins ............................................................................................................... 4-3 4-2 Centralia Wastewater Treatment Plant Process Flow Schematic................................................. 4-7 5-1 Existing (2014) System Surcharging .............................................................................................. 5-3 5-2 Centralia Station Development, Alternative 1 ............................................................................ 5-10 5-3 Centralia Station Development, Alternative 2 ............................................................................ 5-11 5-4 Ford’s Prairie Basin Urban Growth Area ..................................................................................... 5-27 5-5 New Sewer (NS) and Unsewered (US) Projects .......................................................................... 5-28 5-6 Cook’s Hill Basin Urban Growth Area ......................................................................................... 5-35 5-7 Waunch Prairie Basin Urban Growth Area ................................................................................. 5-39 5-8 Widgeon Hill Basin Urban Growth Area ..................................................................................... 5-42 5-9 New Riprap Locations ................................................................................................................. 5-45 5-10 Riprap Cross Section ................................................................................................................... 5-46 5-11 I/I Reduction Project ................................................................................................................... 5-51 6-1 Process Capacity Summary ......................................................................................................... 6-10 6-2 Projected Loading versus Proposed Capacity, Maximum Month ............................................... 6-11 6-3 Projected Flow versus Proposed Capacity, Maximum Month .................................................... 6-12 6-4 Conceptual Layout of the WWTP Improvements ....................................................................... 6-25 6-5 Process Flow Diagram for the Phase I and Phase II Improvements ............................................ 6-27 6-6a Hydraulic Profile for the Centralia WWTP Phase I Improvements ............................................. 6-29 6-6b Hydraulic Profile for the Centralia WWTP Phase II Improvements ............................................ 6-31 6-7 Plan View of the Proposed Modifications................................................................................... 6-35 6-8 Section View of the Proposed Modifications .............................................................................. 6-37 BI1212191438SEA xi Acronyms and Abbreviations °C degree(s) Celsius AAF average annual flow AFD adjustable-frequency drive ASR aquifer storage and recovery BFP belt filter press BOD biochemical oxygen demand BOD5 5-day biochemical oxygen demand BPS booster pump station C Candidate CCI Construction Cost Index CCTV closed-circuit television cfs cubic foot/feet per second CH2M CH2M HILL Engineers Inc. C.I.P. Capital Improvement Plan CIP cast-in-place CIPP cured-in-place pipe City City of Centralia CMC Centralia Municipal Code DMR discharge monitoring report DO dissolved oxygen DU dwelling unit DU/acre dwelling unit(s) per acre DWMM dry weather maximum month E Endangered Ecology Washington State Department of Ecology ENR Engineering News-Record EPA U.S. Environmental Protection Agency FOG fats, oil, and grease fps foot/feet per second FTE full-time equivalent General Sewer/ Centralia General Sewer and Facility Plan Facility Plan GMA Growth Management Act ACRONYMS AND ABBREVIATIONS xii BI1212191438SEA gpcd gallon(s) per capita per day gpd/sf gallon(s) per day per square foot gpm gallon(s) per minute HDPE high-density polyethylene hp horsepower I/I infiltration and inflow I/O input/output I-5 Interstate 5 JARPA Joint Aquatic Resource Permit Application lbs/d pound(s) per day lbs/hr/m pound(s) per hour per meter Lewis County Plan Comprehensive Land Use Plan for Lewis County, Washington (Lewis County, 2013) lf linear foot/feet M Monitor MBR membrane bioreactor MCC motor control center MDDF maximum day design flow MG million gallon(s) mg/L milligram(s) per liter mgd million gallon(s) per day mL milliliter(s) MLR mixed-liquor recirculation MLSS mixed-liquor suspended solids MLVSS mixed-liquor volatile suspended solids MWDF maximum week design flow N/A not applicable NPDES National Pollutant Discharge Elimination System NRCS Natural Resources Conservation Service NS New Sewer O&M operations and maintenance Orange Book Criteria for Sewage Works Design P package pump station PHDF peak hour design flow PHS Priority Habitats and Species ACRONYMS AND ABBREVIATIONS BI1212191438SEA xiii PIDF peak instantaneous design flow PLC programmable logic controller ppcd pound(s) per capita per day ppd pound(s) per day ppd/sf pounds per day per square foot PRV pressure-reducing valve PS pump station psi pound(s) per square inch PT Proposed Threatened PVC polyvinyl chloride RAS return activated sludge RCW Revised Code of Washington RPA reasonable potential analysis S Sensitive SC Species of Concern SCADA supervisory control and data acquisition scfm standard cubic foot/feet per minute SEPA State Environmental Policy Act SERP State Environmental Review Process sf square foot/feet SPR spiral-wound pipe renewal SRF State Revolving Fund SRT solids retention time STEP septic tank effluent pumping SVI sludge volume index SWCAA Southwest Clean Air Agency SWD side water depth T Threatened TKN total Kjeldahl nitrogen TMDL total maximum daily load TN total nitrogen TSS total suspended solids UGA Urban Growth Area UGB Urban Growth Boundary US Unsewered Communities ACRONYMS AND ABBREVIATIONS xiv BI1212191438SEA USGS U.S. Geological Survey UV ultraviolet VFD variable-frequency drive VSS volatile suspended solids WAC Washington Administrative Code WAS waste activated sludge W/D wet well and dry well WDFW Washington Department of Fish and Wildlife W/S wet well, submersible pump WSDOT Washington State Department of Transportation WWMM wet weather maximum month WWTP wastewater treatment plant CHAPTER 1 BI1212191438SEA 1-1 Introduction This chapter provides a brief history of the City of Centralia’s (City’s) sewer collection and treatment systems, demonstrates the compatibility of the City’s General Sewer and Facility Plan (General Sewer/Facility Plan) with other plans, identifies the designated land uses within the existing and future service area, and presents population projections within the City’s planning area. The General Sewer/Facility Plan must be developed and coordinated to support the growth projected in adopted Lewis County comprehensive plans at the time development occurs and is ready for occupancy. At the same time, the General Sewer/Facility Plan must continue to provide established minimum levels of service to the existing population. This General Sewer/Facility Plan will serve as the planning document for the City's sewer service for the next 20 years. 1.1 Background According to Washington Administrative Code (WAC) 173-240-020(7), a general sewer plan is defined as “a comprehensive plan for a system of sewers adopted by a local government entity.” In order to provide sewer service in Washington, a governmental entity must have a plan that is reviewed and approved by Washington State Department of Ecology (Ecology). A general sewer plan typically describes the general location and process of treatment and disposal facilities, trunk and interceptor sewers, pump stations, monitoring and control facilities, and local service areas. Per WAC 173-240-060, a facility plan is defined as “a document which thoroughly examines the engineering and administrative aspects of a particular domestic or industrial wastewater facility.” (Washington State, 2018) 1.1.1 System Ownership and Management Centralia is located in Lewis County, approximately 25 miles south of Olympia. The City owns and operates a wastewater collection and treatment system located within the City limits. Sewage collection, treatment, and disposal are provided through a conventional gravity collection system and a treatment facility that includes screening, grit removal, activated sludge aeration basins, secondary clarifiers, and ultraviolet (UV) disinfection prior to discharge to the Chehalis River. The WWTP, 25 pump stations and the associated collection and conveyance system are owned, operated and maintained by the City of Centralia wastewater department. The City has approximately 39 grinder pumps installed throughout the City. Currently, the City and grinder pump homeowner’s have a service agreement that states that the homeowner’s are responsible for performing the proper maintenance either by a qualified individual or firm. The City’s Municipal Code Title 15.10.180 Paragraph H outlines the use of alternative systems which covers the installation, ownership and maintenance of the systems. The City is planning to add a list of approved qualified contractors that can perform maintenance on these systems. All maintenance and inspections scheduled will be tracked and maintained by the City of Centralia maintenance program. 1.1.2 Projects Completed Since the Previous Plan The sewer portion of this document was last updated in 2008. Since then, the City has implemented several of the recommended projects identified in the last update. Table 1-1 provides a list of projects that have been completed since the last update. CHAPTER 1 – INTRODUCTION 1-2 BI1212191438SEA Table 1-1. Projects Completed Since the Previous Plan Designator Name F-8 Galvin Road area US-1 West Cooks Hill US-8 Scammon Creek Residential ES-2 Replace existing trunk sewer along Fifth and Sixth Streets ES-3 Borst Park ES-5 Maple and Hansen on North Pearl and along Railroad ES-6 Euclid Way ES-7 Oxford between 6th Street and Vienna Street N/A Telemetry required at Mt Vista, Jensen, and State pump stations N/A Sliplining the gravity main under China Creek Note: N/A = not applicable 1.1.3 Overview of Existing Systems Centralia city limits encompass approximately 7.6 square miles or 4,927 acres, while the Urban Growth Area (UGA) consists of 8.2 square miles or 5,227 acres and includes parts of unincorporated Lewis County. Together, the UGA and the incorporated City of Centralia make up the City’s Urban Growth Boundary (UGB). According to the City’s Comprehensive Plan (City of Centralia, 2017), “the primary purpose of Centralia’s UGB is to define the area where public expenditures already have been made for service facilities or will be in the future and to guide development to that area in order to make more efficient use of public investments.” Centralia is primarily a residential community. As of 2015, the City provided service to approximately 15,570 customers within the City’s sewer service area. The City’s sewer system consists of 1 treatment plant, 25 pump stations, and approximately 70 miles of gravity collection and 19 miles of force main pipes. A summary of sewer system data is provided in Table 1-2. Table 1-2. Summary of Sewer System Data Description Data 2015 Estimated Population (City) 16,790 2015 Estimated Sewer Population 15,570 Total Sewer Connections 6,488 Average Gallons per Capita per Day 126 Average Flow (mgd) 1.92 Number of Pump Stations 25 Length of Sewer Main (miles) 70 Length of Force Main (miles) 19 Note: mgd = million gallon(s) per day 1.2 Purpose In February 2016, the City authorized CH2M HILL Engineers, Inc. (CH2M) to prepare a General Sewer/Facility Plan in accordance with WAC 173-240-050 and 173-240-060. The General Sewer/Facility CHAPTER 1 – INTRODUCTION BI1212191438SEA 1-3 Plan provides the City with a framework to plan for improvements in the collection system and at the wastewater treatment plant (WWTP) as growth occurs inside the City’s sewer service area. The previous General Sewer Plan update was prepared and submitted to Ecology in 2015. The purpose of this updated General Sewer/Facility Plan is to address comments from Ecology on the 2015 General Sewer Plan and to update the plan with the following items: • Update the existing and projected sewer flows and loads. • Update the infiltration and inflow (I/I) analysis to evaluate the extent of I/I according to guidelines set forth by the U.S. Environmental Protection Agency (EPA). • Analyze the existing sewer system to determine if it meets minimum requirements mandated by Ecology and the City’s own policies and design criteria. • Identify sewer system improvements that will resolve existing system deficiencies and accommodate future system needs. • Determine the overall reliability and vulnerability of the existing wastewater lift stations. • Identify surface water discharge criteria • Evaluate and plan for the impacts of potential nutrients limitations. • Evaluate the impacts of metals and temperature on wastewater treatment. • Evaluate plant flow and loading capacity. • Evaluate wastewater treatment and disposal alternatives. • Prepare a schedule of improvements that meets the goals of the City’s financial program. 1.3 Regulatory Requirements In addition to the City’s need for a General Sewer/Facility Plan, other regulations also govern the development of this plan. These regulations are briefly summarized in this section. 1.3.1 Growth Management Act Under the requirements of the 1990 Growth Management Act, the City must commit to serving the sewer needs of the planned growth that will occur within the City's urban growth boundary within the next 6 years. This General Sewer/Facility Plan includes an evaluation of the existing sewer system and identification of additional facilities needed to accommodate the planned growth to comply with state regulations. This information has been used to develop the Capital Improvement Program presented in Chapter 8 of this General Sewer/Facility. 1.3.2 Washington State Department of Ecology This General Sewer/Facility Plan was prepared in accordance with the requirements of Ecology as defined in WAC 173-240, which states that a sewer plan should accomplish the following: • Include sufficient detail to assure the technical feasibility of proposed sewer system improvements. • Provide a method of distributing the cost and expense of the sewer system. • Demonstrate the financial feasibility of the plan implementation. Ecology is responsible for reviewing and approving plans for sewer collection and treatment systems. Before Ecology will review and approve project implementation, the City must have an Ecology- approved sewer plan that describes the need for each project and how the project will fulfill that purpose. The City also needs a Facility Plan before it can receive assistance for those projects from the State of Washington grant and loan programs. CHAPTER 1 – INTRODUCTION 1-4 BI1212191438SEA 1.3.3 Lewis County The Comprehensive Land Use Plan for Lewis County, Washington (Lewis County Plan) (Lewis County, 2013a) was adopted in June 1999 and updated most recently in 2013. It identifies specific policies that are addressed in this General Sewer/Facility Plan. First, extension of sanitary sewer service should be prioritized to those areas where onsite sewage disposal systems have created known pollution or health hazards. Second, primary fiscal responsibility for provision of new services to proposed developments lies with the developer. This General Sewer/Facility Plan also acknowledges the Countywide Planning Policies for Lewis County (Lewis County, 2013b), which require that sewer service extensions be limited to within the City boundary except to solve immediate health or safety problems. Sewer systems for proposed developments within the City's adopted urban growth boundary where urban sewer systems are not available must be designed, sited, and built to facilitate eventual conversion to urban sewer systems. 1.4 General Sewer/Facility Plan Organization • Executive Summary summarizes the plan. • Chapter 1 introduces the reader to the City’s sewer system, the objectives of the plan, and the plan organization. • Chapter 2 presents the sewer service area, describes the existing sewer system, and discusses related plans, land use, and population characteristics. • Chapter 3 presents existing and projected future wastewater flows and loads. • Chapter 4 discusses the facilities within the City’s existing sewer system. • Chapter 5 presents collection system analyses and recommended improvements. • Chapter 6 presents the treatment plant capacity evaluation and future treatment plant upgrades. • Chapter 7 discusses the City’s operations and maintenance program. • Chapter 8 presents the implementation schedule as a Capital Improvement Plan (C.I.P.) and discusses the City’s financing options for the C.I.P. projects. • Chapter 9 summarizes the implementation strategy for adopting the General Sewer/Facility Plan. • Chapter 10 lists references cited. • Appendices 1.5 Required Content The required contents for Facility Plans and General Sewer Plans are included in the Ecology’s Criteria for Sewage Works Design and WAC 173-240-050. Ecology provided additional comments to be addressed when the 2014 General Sewer Plan Update was approved (Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015). A crosswalk demonstrating this General Sewer/Facility Plan’s alignment with these requirements is included in Appendix A. CHAPTER 2 BI1212191438SEA 2-1 Service Area and Vicinity Characteristics This chapter describes the Centralia sewer service area, including a brief history of the City’s sewer collection and treatment systems, existing environment, and municipal water system. It also demonstrates the compatibility of the City’s General Sewer/Facility Plan with other plans; identifies the designated land uses within the existing and future service areas; and presents population projections within the City’s planning area. The plan must be developed and coordinated to support the growth projected in adopted comprehensive plans at the time development occurs and is ready for occupancy. At the same time, the plan must continue to provide established minimum levels of service to the existing population. 2.1 Sewer Service Area The City's sewer system consists of a network of sewer trunks, laterals, force mains, and pump stations that transport the collected sewage to the City's WWTP. Figure 2-1 presents the vicinity map of the City, and the City's current and future sewer service area boundaries are presented in Figure 2-2. 2.1.1 General History The City’s initial collection system was constructed mostly of clay pipe between 1906 and 1914 to serve the downtown area. The system was expanded using concrete pipe between 1924 and 1970 to include areas west and north of downtown, as well as Fords Prairie. Concrete pipe installed before 1965 used mortar joints between the pipe lengths. It was not until after 1965 that gasketed joints were widely used. Asbestos-cement and concrete pipe were used to expand the collection system between 1960 and 1975 west and south of the original WWTP. Polyvinyl chloride (PVC) pipe has been used for subsequent expansions, such as Fords Prairie and Waunch Prairie. Much of the system is in low-lying areas with highly permeable gravelly soils. Because of the flatness of the terrain, outlying developments had to use pump stations to convey sewage to the collection system or the WWTP. As a result, several pump stations serve a single development, and the City has numerous stations to operate and maintain. The City’s original WWTP was located east of the Mellen Street Bridge and was completed in 1951. The WWTP consisted of headworks, primary clarifiers, trickling filters, secondary clarifiers, disinfection, dechlorination and an outfall to the Chehalis River. In 2004, a new WWTP was constructed that replaced the original WWTP. It is located northwest of the City limits adjacent to the Chehalis River and south of the Thurston County border. The new WWTP includes screening, grit removal, activated sludge aeration basins, secondary clarifiers, and UV disinfection prior to discharge to the Chehalis River through a multi- port diffuser at river mile 61.25. 2.1.2 Sewer Drainage Basins The service area where the City currently provides sewer service, or is planning to provide service in the future, is divided into 29 sewer drainage basins. Lewis County is responsible for all sewer service outside the service area including onsite disposal systems such as septic tanks. Figure 2-2 shows the boundary of each of the sewer basins. UNK F:\CENTRALIA_SEWERWASTEWATER\GIS\MAPFILES\CENTRALIA_SEWER_85X11_PORTRAIT_VICINITY.MXD LH013853 7/28/2016 4:26:35 PM §¨¦5 §¨¦5 £¤12 £¤12 UV603 UVe 6 UV507 UV508 UV6 LEW IS C OUN TY TH UR STON COUN TY Chehalis Napavine Bucoda Centralia Data Sources: WSDOT, King County, Lewis County, US Census Bureau, USGS FIGURE 2-1Vicinity MapCity of CentraliaGeneral Sewer/Facility Plan ProjectLocation Tacoma Seattle Spokane Vancouver Bellingham Port Angeles Legend Rail River or Stream Lake or Pond Centralia City County¯0 1.5 30.75 Miles Locator Map W.L.129.3 CHEHALIS RI VER W.L.131.6 W.L.131.8 W.L.134.9 ? W.L.136.7 DRY CREEK W.L.137.5 ? ? W.L.137.9 ? W.L.139.5 ? ? ? 140 140 140 140 140 140 140 140 140 140 140140 140 140 140 140140140 140 140 140140 140 140 140 140 140 140 140 140 140 140 140140 140 140140 W.L.140.4 ? ? ? ??? ? ? PIPE ? W.L.143.7 W.L.144.3 ? ? ? ? ? ? ? ? W.L.147.0 W.L.147.0 ?WAGNERRDWAGNER150 150 150 150 150 GOODRICH RD RD RDDRYCRE EK 150150 150150150160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 160 TRAILERS 160 160 160 160 160 160 160 160HARRISON AV E GOODRICH HARRISONRECAREA B NRR BN RR PAVED PARKING TRAILER COURT BNRR RDOPENSTORAGECHEHALIS WES TE RN RR170 170170 170 17 0 170 170 170 170 170 170 170 S MITH RDI-5 C HEHA LIS WEST E R NI-5 180 180 180180 180 180 180 190 200 200 200 200 220 220 22 0240 UP R/R (ABANDONED UP R/R ) BURLINGTON NORTHERN R/R NORTHERN R/RBURLINGTON CHEHALIS WESTERN R/RBURLINGTON NORTHERN R/R( I - 5 FREEWAY ) ( I- 5 F RE E WA Y ) S ALZE R CRK. CRK. CHINARIVERSKOOK UM CHUCKCOFFEE CRK.RIVE RSKOOKUMCHUCK SCAMMON CRK. SK OOKUM CHUCK RI VER PARK BORST FORT LAKEPLUMMER LAKEHAYES CHEHALIS RIVER SUMMA ST. JOHNSONSCOTT - REYNOLDS AVE. RAINIERL ST.K ST.J ST.H ST.G ST.F ST.E ST.HANAFORD RD.BIG RAYMOND RD. CHENY LANE SAWALL AVE.CAROL RD.HOWARD AVE.EUREKA AVE.NOEL AVE. CINDY RD.SEWARD AVE.EUREKA AVE.SIRKKA ST.CARSON ST. PURVIS BURT ROANOKE ST. OAKVIEW AVE. SCOTT ST. SUSAN ST.ARUNDELWILLIAMSLYNNW. ROANOKE ST. ALASKA WAY FREMONT AVE. TACOMA AVE.HILVIEW RD.BEACH ST.NORTH TOWER AVE.MAY ST.B ST.NORTH TOWER AVE.NORTH PEARL ST.WARD ST.KEARNEY ST. MERIDAN AVE.PROSP ECT AVE.CRESENT AVE.CENTRAL BLVD.LITTLE HANAFORD RD.ROSE ST.MC ATEE RD.LUNDBERG RD.HALIDAY RD.ST. HELENSRHOBINA ST.BAYNE ST. LINCOLN ROYALKULIEN AVE.LOGAN ST.AVE.HIGHLAND PIKE ST.VIENNA ST. WARSAW ST. VIENNA ST. FULTON ST. WARREN ST. DELAWARE AVE.WINDSO R AVE.OXFORD ST.MARION ST.CROSBY AVE.HAM HILL RD.MADRONA AVE.THIRD ST. YAKIMA ST.N. GOLD ST.BELL RD.GLEASON RD.DR.MEADOWSKYHAM HILL RD. ROSWELL RD. GIRARD ST. DAVIS MAGNOLIA ST. MAPLE ST.ST.BYRDST.DUFFY RD. HILL SE MIN A RY PLEASANT AVE.PINE ST.SAXON ST.GREEN ST.BARNER DRIVE BERRY ST.DIAMOND ST.BUCKNER ST.MAIN ST. LOCUST ST. PEAR ST. PLUM ST. CHERRY ST.TOWER AVE.PEARL ST.CHESTNUT ST. NORTHRUP ST.GOLD ST,FIELD ST.BUCKNER ST.CHESTNUT ST. SPRUCE HICKORY ST. VAN BUREN ST.ROOSE VELT AVE.JEFFERSON ST.TOWER AVE.PEARL ST.SILVER ST.GOFF ST.ALVORD RD.PACIFIC AVE.CENTRALIA AVE.STATE ST. GROVE ST. STATE ST. UNION AVE. FAIR ST.KRESKY AVE.GRAND AVE.SO. GOLD ST.KRESKY AVE.SO. GOLD ST.HAMPE RD. EXHIBITOR RD. SEVENTH ST. SIXTH ST. FIFTH ST. FOURTH ST. THIRD ST. SECOND ST. FIRST ST. PARK WAY HILKREST AVE.SILVERIRONROCK ST.OAK ST.MAPLE ST. HANSEN ST. CENTER ST. MAGNOLIA ST. PINE ST.ASH ST.WASHI NGTON AVE.KING ST.SILVER ST.IRON ST.ROCK ST.OAK ST.MAIN ST. LOCUST ST. WALNUT ST. PEAR PLUM ST. CHERRY ST. LOCUST ST. WALNUT ST. PEAR PLUM ST. CHERRY ST. WASHI NGTON AVE.KING ST.ASH ST.CHESTNUT ST. ELM ST. FLORAL AVE. SOU TH ST. BROTHERSON RD.LONG RD.SOUTH ST.WOODLAND AVE.SUMMA ST. HUNT ST. ST. JACKSON JEFFERSON ST. HA MILT ON AVE. MADISON ST.ATHERTON ST. RICHMON D ST. ALDER ST. ALDER ST.YEW ST.BORTHWICK ST. MARS H ST.MELLEN ST.ELLSBURY ST.LAKESHORE DR.CEDAR ST.YEW ST.HEMLOCK ST.COURTLAND ST.LAKESHORE DR.BENJAMIN ST.MAIN ST.L ST. ORTON TILLEY AVE. LEWIS ST. W. MAIN ST.LATONA ST.DENNY WAYAURORA ST. ALEXANDER ST.M ST.M ST .N ST .FIRST ST. BRIDGE ST. HARRISON AVE.LOWE ST. HIGH ST.SHIRLEE AVE.ERICKSON RD.SUNSET WAY BELMONTJENSEN ST.INDUSTRIAL DR.JOHNSON RD.REYNOLDS AVE. NINTH ST. EARL ST.LUM RD.HAVILAND ST.BELMONT AVE.VIEW AVE.BORST AVE. CAVENESS DR.JOHNSON RD.LINDA LN.HARRISON AVEVAN WORMER RD.TAYLOR RD.GALVIN RD. FORDS PRAIRIE AVE. RUSSELL RD. SUNNYSIDE DR.KAYU LANEJAYLYN CRT.JAYLYN ST.ALLEN AVE.SANDYSHARON ST.BRYDEN AVE.SCOTT DR.BENGAL CRT.OAKLAND AVE.SOUTHGATE DR. MT. VISTA RD. BORST AVE.SCHEUBER RD.SCAMMON CR. RD.J. GRAF RD.NICK RD.SHAMROCK DR. MILI TARY RD.WAYNE DR.W. MELLEN ST. COOKS HILL RD.SOTUH SCHEUBER RD.COOKS HILL RD.SUNSET DR.SWANSON DR.SPRING LANEDAVIS HILL RES. SEMINARY HILL RES. UNION PACIFIC R/R R/WRODCIN AVE. MAYBERRY RD. ALBERTA DR. PRILL RD.GREENWOOD LN.FIELDCREST AVE.MASON AVE.RANCHO RD.STEWART PL.LEMAR LN.WASHINGTON WAYKRISTAM PL. TRAVERA PL.MELODY CT. EASTWOOD LN. MARDON PL.GALLAGHER RD.IVES RD. NORTHPARK DRIVE BENNETT RD. HORSLEY AVE.FORON RD.SANDRA RD.COWLITZ RD.PHEASANT RD.TIGER LN. LAUREL LN. GALVIN RD.RI VERHEI GHTS R D. GA LVIN RD. LINCOLN CREEK RD.JOPPISH RD.WILSON LN. RIVERHEIGHTS RD.RIVER HEIGHTS RD.SANDY BLVD.JOPPISH RD.COOKS HILL RD. BL ANC HA RD RD. RD. SUMMERSIDE CLEARVIEW HEIGHTS WOOD HAV EN DR.W. ROANOKE ST.CHEHALIS RIVER HAM HILL RES. COOKS HILL RES. B B B B B CENTRALIA - ALPHA RD.50,000 GAL.S 3.5 MIL. GAL.S 80,000 GAL.S 4.5 MIL. GAL.SPo n d SCOTT RD FILE NAME: 0 1000 2000 3000 Scale In Feet 10-JUN-2014 08:07:50 City of Centralia 1 16 1 2 3 6 17 2512 11 78 9 10 13 14 15 27 5 24 19 18 22 21 20 4 26 Pump Station Sewer Basins City Boundary LEGEND SEWER SERVICE AREA AND BASINS fig2-8.dgn General Sewer/Facility Plan Figure 2-2 23 28 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 North Port Salzer Creek Gravity Long High Jefferson State Floral Ace Auto Fairgrounds Van Buren S. Tower Reynolds Marion Military W. Mellen Scammon Borst Park Jensen Mt Vista Eshom Schueber Industrial S.E. Gravity Downtown Gravity Downtown Gravity Downtown Gravity Downtown Gravity Downtown Gravity 29 25 Number Basin CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-5 2.1.3 Onsite Sewer Systems Prior to 2000, documented septic system failures in the Fords Prairie and Waunch Prairie areas have resulted from the Type 1 soils in those areas, which are gravelly or sandy and highly permeable. There are no known geologic barriers between the ground surface and the groundwater. These prairies have groundwater elevations ranging between 10 to 60 feet below the ground surface, depending on location and time of year. To protect public health, the Lewis County Health Department recommended that improved septic designs be used, including pressure distribution and mound systems. The higher level of treatment attained with the improved septic system designs is considered adequate to protect public health in the Fords Prairie and Waunch Prairie areas. Onsite sewer systems are permitted by the Lewis County Health Department. Lewis County has not completed any sanitary surveys since 1999. Operation and maintenance of onsite sewer systems can be found on the Lewis County Onsite Septic Program website (https://lewiscountywa.gov/environmental- health/operating-and-maintenance). 2.1.4 Unsewered Areas The following are known unsewered areas within the City limits: • Central Boulevard • Linda Lane • Mountain View Trailer Park • Reynolds Road • North end of Waunches Road • 1300 and 1400 block of W. Main Street 2.2 Existing Environment 2.2.1 Topography, Geology, and Soils 2.2.1.1 Topography The Chehalis Valley is characterized by a broad floodplain and low terraces surrounded by upland valleys of low to moderate relief that have broad, rounded ridges. The Chehalis Valley and Salzer Valley to the south and east are flat and range in elevation from 180 to 220 feet above sea level. Waunch Prairie and Fords Prairie, and Zenkner and Hanaford valleys to the north, are also flat and range in elevation from 210 to 230 feet above sea level. Figure 2-3 presents the topography and natural drainage basins within the service area as a vicinity map of the area surrounding the treatment plant. East of the study area, the slope rises abruptly to a plateau approximately 500 feet in elevation. To the north and northwest, valleys and prairies are separated by finger ridges, with slopes that rise moderately to abruptly. The typical elevation of these ridges is 500 feet. Fords Prairie follows the Chehalis River northwest and opens into a broad area referred to as Grand Mound Prairie. 2.2.1.2 Geology Geologic deposits in the Chehalis River valley are primarily non-glacial alluvium (sediments deposited by rivers in relatively recent times) consisting of silt, loam, sand, and gravel. Directly east and northeast of Centralia are the Cascade foothills, which are made up of marine sedimentary rock consisting primarily of sand and silt stone. Farther east, glacial and alpine outwash deposits of sand and gravel predominate with minor amounts of silt and clay. The primary geologic formation in this area is the Skookumchuck CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-6 BI1212191438SEA formation, which developed during the late Eocene and Oligocene epochs 27 million to 40 million years ago. To the west of the City are small, discontinuous areas of the Skookumchuck formation. Adjacent to these areas is a large segment of near-shore sedimentary rock consisting of sandstone, siltstone, shale, claystone, and coal interbedded with lava flows and brackish water deposits. To the north and east of the City, there is a known seismic fault. According to the Geologic Map of Southwest Washington, produced by the Department of Natural Resources (year unknown), there is an inactive syncline over 25,000 years old. 2.2.1.3 Soils The primary soils in the downtown Centralia area are in the Spanaway soil series. Spanaway gravelly, sandy loam is composed of very deep, somewhat excessively drained soils found on glacial outwash terraces and plains. Permeability of this soil is moderately rapid to a depth of 18 inches and very rapid below this depth. Runoff is slow, and the hazard of water erosion is slight. The very rapid permeability of the soil limits filtration and absorption of contaminants, such as those resulting from septic tank fields, pesticides, and automobiles. Soils in the northern and western portions of the study area are primarily Newberg fine sandy loam and Chehalis silty clay. The Newberg soil is very deep and well drained, and it is found on river flood plains and low terraces. Permeability is moderately rapid, and runoff is slow. This soil is subject to occasional brief periods of flooding in winter and early spring. Chehalis silty clay is also very deep and well drained, and it is found on low stream and river terraces. Permeability of this Chehalis soil is moderate, and runoff is slow. This soil is also subject to occasional brief periods of flooding in winter and early spring. Soils found in the south are mostly Indianola loam sand and Nisqually loamy sand. Both soils are very deep, somewhat excessively drained, and located on terraces and broad plains. Permeability is moderately rapid in the surface layer and rapid below. Runoff is very slow. The rapid permeability of the soil restricts filtration and absorption of contaminants caused by septic tanks, pesticides, and automobiles. To the east, in the Cascade foothills, Buckpeak silt loams are found. This is a very deep, well-drained soil located on hillsides and ridgetops. Permeability of Buckpeak soil is moderate, runoff is medium, and the hazard of water erosion is moderate. To the southeast and northeast, along Salzer Valley and China Creek, there are Reed silty clay loams. This very deep, poorly drained soil is found on floodplains. Drainage has been altered by tiling, and permeability and runoff are slow, resulting in frequent seasonal flooding. 2.2.2 Climate Based on historical data from U.S. Climate Data (NOAA, 2016), the climate in the City is typical of Lewis County. The average summer temperature is 62 degrees Fahrenheit with an average daily maximum temperature of 74 degrees Fahrenheit. The average winter temperature in Centralia is 42 degrees Fahrenheit with an average daily minimum temperature of 35 degrees Fahrenheit. Precipitation most often occurs during the months of October to April, with the heaviest rains generally occurring during the month of November. The average total annual precipitation for Centralia is 47 inches. UNK F:\CENTRALIA_SEWERWASTEWATER\GIS\MAPFILES\CENTRALIA_SEWER_11X17_LANDSCAPE_TOPOGRAPHIC.MXD LH013853 7/28/2016 4:44:06 PM Existing WWTP LEWIS COUNTY THURSTON COUNTY Centralia §¨¦5 §¨¦5 H a r r i s o n A v e Cooks Hill Rd Teitzel RdGraf RdSalzer Valley RdBig Hanaford Rd Galvin Rd Little Ha n a f o r d R d Seminary Hill Rd Airport RdJoppish RdJ StHam Hill Rd S Scheuber RdForon RdB l a i r R d B StBorst Ave N Gold StBl a n c h a r d R d W Main S t Wigley RdYew StIves R d S Silver StGoodrich RdSummers RdFair StEureka AveMattson RdW Reynolds Ave River He ights Rd Lincoln Cr e e k R d Marion St Smith Rd McAtee RdKuper Rd Blue RdShelley DrState St L i n c o l n A v e Battler i d g e R d Brier Rd£¤12 £¤12 UV507 Hayes Lake PlummerLake Horseshoe Lake Fort Borst Lake Chehalis River Han a f o r d C reekSkooku m ch u ck R iv er200300400500600800300 3 0 0500 3 0 0 400 300200 4 0 0 50 0400 600200 500200 300300200 400 300500 500 6005006 0020020 0 4 0 0 500 5006002 0 0 2 0 0 200200 40020 0200400 500 4 0 0 400 500 50 0 200200 400 200400600 200400 200 500 200500 200300500400 5 0 0 20020050040040020030 0 200 200 200200300 400 400200200400 200200 400500 300 200 40 0200200 200 200600200 20 0 300400500500 400 4002003 0 0 200600200 500 300 200300 Sources: Esri, USGS, NOAA Data Sources:Esri, NOAA, WSDOT, King County, Lewis County, US Census Bureau, USGS FIGURE 2-3Topography MapCity of CentraliaGeneral Sewer/Facility Plan Project Location Tacoma Seattle Spokane Vancouver Bellingham Port Angeles ¯0 0.55 1.10.275 Miles Legend Rail Waterbody City Urban Growth Area (UGA) County 1,000 100 Elevation (feet) CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-9 2.2.3 Air Quality Under federal regulations, areas that violate primary ambient air quality standards are designated as nonattainment areas, and State Implementation Plans must be developed to bring these areas into attainment. Based on local air quality monitoring data and analysis by Ecology and the Southwest Clean Air Agency (SWCAA), the EPA has determined that the Lewis County area is either in attainment or unclassified for each of these standards. In short, the air quality is good, and the focus of air quality regulatory efforts is to confirm that it remains the same for the future (CH2M, 1999). The SWCAA is responsible for regulating air quality in Centralia. The largest concern for air quality problems in Centralia appears to be the proximity to the Centralia Coal Plant. Combustion of coal produces emissions of sulfur dioxide, nitrogen oxides, particulate matter, carbon monoxide, volatile organic compounds, and certain hazardous air pollutants in sufficient quantities to designate the facility as a Title V source of air pollutants. Additionally, all burning was permanently banned within City limits and UGAs in January 2016. 2.2.4 Water Resources 2.2.4.1 Surface Water The Chehalis River Basin is the second largest drainage basin in the state and covers 2,114 square miles in western Washington. The cities of Centralia and Chehalis lie in the center of the basin. In the Centralia area, the largest tributary to the Chehalis River is the Skookumchuck River. Other smaller tributaries within the study area include Salzer Creek, China Creek, Hanaford Creek, Coffee Creek, and Scammon Creek. The Chehalis River and its tributaries are shown on Figure 2-4. Chehalis River: The main stem of the Chehalis River is composed of over 100 river miles and covers a drainage area of approximately 123 square miles. Most of the river's drainage is outside of the Centralia City limits. The Chehalis River supports a diverse variety of aquatic life. Important salmon runs include spring, fall, and summer Chinook, coho, and chum. Salmon are present within the Chehalis River on a year-round basis. The portion of the Chehalis River located within the Centralia Urban Reserve Boundary is not a prime spawning area but does serve as a transport zone for both spawning and ocean-bound salmon. River banks in this area are commonly lined with deciduous trees or brush, or both. The Chehalis River Basin is not glacially fed, although snowmelt flows make a minor contribution to flows in the upper Skookumchuck River and Newaukum River watersheds. Skookumchuck River: The Skookumchuck River headwaters begin in the foothills of the Cascade Range, and the river meanders southwesterly along the Waunch Prairie until it joins the Chehalis River at river mile 67 between Hayes Lake and Plummer Lake. The Skookumchuck River covers 38 river miles and covers a drainage area of 180 square miles. The river provides migration, spawning, incubation, and rearing waters for coho, spring Chinook, and fall Chinook salmon. Salmon spawning and rearing occurs in riffles between the mouth of the river and the Skookumchuck Dam. All the main stem Skookumchuck River and at least 43 miles of tributary streams are used by salmon for spawning. Salzer Creek: Salzer Creek runs northwest along the Salzer Valley, then turns south and west until it meets the Chehalis River west of Interstate 5 (I-5). The Salzer Creek drainage basin consists of approximately 17.3 square miles, passing mostly through agricultural and forested lands. Although a portion of Salzer Creek is inside the City (north and west of the fairgrounds), the majority of the creek is located outside the City. Hanaford Creek: Hanaford Creek is a major tributary of the Skookumchuck River. A major open-pit coal mine and power plant is located next to the creek. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-10 BI1212191438SEA Scammon Creek: Scammon Creek is a short tributary to the Chehalis River and enters the main stem on the southern bank at river mile 65.8. Its flow in the dry season is very low to nonexistent. China Creek: China Creek is mostly a manufactured ditch that flows through the City and discharges to the Chehalis River at river mile 67.3; it is primarily a conduit of urban stormwater during the wet and dry seasons. Coffee Creek: Coffee Creek is a long tributary to the Skookumchuck River that originates in Thurston County and enters the river between I-5 and Pearl Street. A portion of Coffee Creek has been channelized within a drainage-control ditch that extends from West Roanoke Avenue to the Skookumchuck River. Coffee Creek is located within the Thurston/Lewis County Drainage District No. 7. Standing Freshwater Bodies: There are several manufactured lakes within the City boundary and study area. The lakes are located west of the City (Hayes, Plummer, and Fort Borst lakes) and are former borrow pits that were created as a result of the construction of I-5 in the 1950s. These lakes currently provide recreation opportunities for the public (including swimming, fishing, and boating activities). To the east within the study area are two additional small lakes, the result of gravel excavations. These lakes adjoin Coffee Creek, with the larger one abutting the Union Pacific Railroad right-of-way and the smaller one located directly adjacent to Coffee Creek. These lakes no longer provide recreation opportunities due to recent residential development on the perimeters. In addition, a series of small lakes are located to the east of the study area, which were once holding ponds for nearby logging activities. The ponds are no longer used for this purpose. 2.2.4.2 Floodplains, Shorelands, and Wetlands The Chehalis Valley is characterized by a broad floodplain and low terraces surrounded by upland valleys of low to moderate relief that have broad, rounded ridges. To the southeast and northeast, along Salzer Valley and China Creek, there is very deep, poorly drained soil that is typical of floodplains. Drainage has been altered by tiling, and permeability and runoff are slow, resulting in frequent, seasonal flooding. The City lies within the floodplains of the Skookumchuck River in the north, the Chehalis River in the west, and China Creek. Figure 2-5 is a map produced by the City in 2008 that illustrates the boundaries of the 100-year floodplain and floodway for major streams and rivers within and around the UGA. Chapter 4 discusses the impacts of a severe storm to the City’s wastewater collection and treatment system. The shoreline of the Chehalis River is designated a Shoreline of Statewide Significance by the Washington State Shoreline Management Act of 1971. Activities within the shorelines of these waterways are guided by the regulations contained in the Lewis County Shoreline Master Program. Centralia’s Shoreline Master Plan (City of Centralia, 1998) was amended in June 1998 and is currently being updated. It contains policies and regulations that specify permitted uses within these shoreline areas and affords protection to these areas based on the designated shoreline environments. One policy of note reads as follows: “Sewage treatment, water reclamation, and power plants should be located where they do not interfere with other public uses of water and shoreline” (Shoreline Master Plan, Commercial/Industrial Development, Policy) (City of Centralia, 1998). Wetlands are considered a critical area according to the City’s Critical Area Ordinance and are protected by land use regulations in the Centralia Municipal Code (CMC). Because the City is located in a wide, flat valley with minimal slope variation, the community is surrounded by several small to midsize wetlands. Figure 2-6 was produced by the City in 2009 and approximates wetland boundaries within and around the UGA. Almost all the mapped wetlands are either seasonally or temporarily flooded. 2.2.4.3 Federally Recognized Wild and Scenic Rivers None of the rivers or tributaries within the study area of this plan are listed under the Federal Wild and Scenic Rivers Act. UNK F:\CENTRALIA_SEWERWASTEWATER\GIS\MAPFILES\CENTRALIA_SEWER_11X17_LANDSCAPE_WATERBODIES.MXD LH013853 7/28/2016 4:38:17 PM C hehalisRive r UV507 Existing WWTP Chehalis River Hanaford Creek Skooku m c h u ckRiverHanaford Creek SalzerCreekCoffeeCreek South Ha n aford C r e e k Sc a mmonCreek EagleCreek LincolnCreek Mi l l CreekNorthHanafo r d C r eek CoalCreekCupac o ffe e CreekDryCreek Sou t h B r a nc h S c a m m o n C r e e k CoalCreek China Cree kChinaCreekDry Cree k HayesLake Plummer Lake HorseshoeLake Fort Borst Lake Airport Lake LEWIS COUNTY THURSTON COUNTY Centralia Chehalis §¨¦5 §¨¦5 £¤12 £¤12 UV507 Data Sources:Esri, NOAA, WSDOT, King County, Lewis County, US Census Bureau, USGS FIGURE 2-4Chehalis River and TributariesCity of CentraliaGeneral Sewer/Facility Plan Project Location Tacoma Seattle Spokane Vancouver Bellingham Port Angeles ¯0 0.5 10.25 Miles Legend Rail Stream or Creek Waterbody City Urban Growth Area (UGA) County CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-13 Source: City of Centralia Figure 2-5. Centralia Floodplain Map CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-14 BI1212191438SEA Source: City of Centralia Figure 2-6. Centralia Wetlands Map CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-15 2.2.5 Cultural Resources 2.2.5.1 Prime or Unique Farmland Most of Centralia is developed and is not considered farmland. However, there are a few designated prime farmland areas located mainly in the rich alluvial soils adjacent to the Chehalis and Skookumchuck rivers. The soils in these areas are comprised primarily of Newberg fine sandy loam, with lesser amounts of Chehalis silty clay and Cloquato silt loam. These soils are all designated prime farmland soils by the Natural Resources Conservation Service (NRCS). There are no NRCS-designated unique farmlands in the study area. 2.2.5.2 Archaeological and Historical Sites In order to preserve Washington’s historical and cultural resources, historical, architectural, and archaeological sites can be designated as significant and listed in the National Register of Historic Places or the Washington Heritage Register, or both. Currently, there are nine sites in Centralia listed in the National Register: • Birge, George E., House • Borst, Joseph, House • Centralia Downtown Historic District • Centralia Union Depot • Everest, Wesley, Gravesite • Hubbard Bungalow • Olympic Club Saloon • The Sentinel • U.S. Post Office – Centralia Main There are two additional sites listed on the Washington Heritage Register: • Armistice Day Riot • Fort Borst Blockhouse Prehistoric use of the Chehalis River Valley by Native American people was high due to the abundance of salmon and other resources in the area. The general likelihood of archaeological resources being present is high throughout the study area. Two historical sites are located in the vicinity of the Influent Pump Station: Fort Borst Blockhouse and Joseph Borst House. In 1922, Allen Borst donated 100 acres of his father’s original claim to the City for use as a park where the Borst Blockhouse and Joseph Borst House are currently located. 2.2.6 Endangered Species and Habitats or Threatened Species The Washington Department of Fish and Wildlife (WDFW) maintains the Priority Habitats and Species (PHS) data set. This data set includes species designated at the state or federal level as Endangered (E), Threatened (T), Sensitive (S), candidate (C), and monitor (M). Additionally, the U.S. Fish and Wildlife Service documents wildlife species and their status, including listed and proposed E and T species, C species, and species of concern. Table 2-1 summarizes the current federal and state status of E or T species in Centralia. Important habitats are also found within the study area. WDFW’s PHS database identifies the presence of numerous wetlands (open water and palustrine) along the Chehalis River; anadromous fish runs and priority fish in the Chehalis River; and regular large concentrations of waterfowl along the river. Scrub- shrub and emergent wetlands support regular large concentrations of wintering waterfowl, cavity- nesting ducks, and some Canada goose nesting. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-16 BI1212191438SEA 2.2.7 Public Health There is no declared health emergency in the City related to unsewered communities. However, the groundwater in Fords Prairie and Waunch Prairie has been monitored for possible public health impacts related to contamination of the groundwater by inadequate septic systems. Three sanitary surveys have been conducted by the Lewis County Department of Health in these areas; the most recent survey was in 1990. The surveys have shown increases in the levels of coliform, nitrates, and nitrites over time, although the results indicate that the contamination levels are still lower than drinking water standards. The total number of septic systems in Lewis County and the number of failed systems are unknown. Lewis County Public Health and Social Services requires selected owners to provide site operation and maintenance plans for their septic system. Table 2-1. Federal and State Status of Endangered and Threatened Species in Centralia Common Name Scientific Name Federal Status State Status Marbled Murrelet Brachyramphus marmoratus T T Streaked Horned Lark Eremophila alpestris strigata T E Yellow-billed Cuckoo Coccyzus americanus T C Bull Trout Salvelinus confluentus T C Golden Paintbrush Castilleja levisecta T N/A Kincaid’s Lupine Lupinus sulphureus ssp. kincaidii T N/A Nelson’s Checkermallow Sidalcea nelsoniana T N/A North American Wolverine Gulo luscus PT N/A Bald Eagle Haliaeetus leucocephalus SC S Note: Federal and state status: T = Threatened, M = Monitor, S = Sensitive, E = Endangered, C = Candidate, PT = Proposed Threatened, SC = Species of Concern 2.3 Existing Water System This section provides a description of the City’s existing water system components, while Appendix B illustrates the information as a Water System Facility Map. The information presented in this section is taken from Chapter 5 of the City of Centralia Water System Plan (HDR, 2013). 2.3.1 Sources of Supply The City’s water system currently relies entirely on groundwater for potable water supply. The primary sources of supply for the City are the Tennis Court and Fords Prairie wellfields (including Eshom Well). Seasonal peaking supply is provided by the K Street Well, and the Washington Well serves as an emergency backup supply. 2.3.2 Water Treatment Because the City uses groundwater, its water treatment requirements are primarily disinfection, corrosion control, and, for some sources, contaminant removal. Gaseous chlorine is used for disinfection at the K Street and Washington wells. Hypochlorite disinfection is employed at the Tennis Court and Fords Prairie treatment facilities. Air stripping is also used at these facilities; at the Tennis Court site, the objective is corrosion-control to maintain compliance with the Lead and Copper Rule, and at the Fords CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-17 Prairie site, the objective is removal of perchloroethylene contamination. Fluoride is also added at the Tennis Court and Fords Prairie facilities. 2.3.3 Storage A summary of the City’s existing water storage facilities is provided in Table 2-2. In total, the City’s storage volume is approximately 8 million gallons (MG). Table 2-2. Existing Water Storage Facilities Name Date of Construction Capacity (MG) Construction Material Elevation (feet) Dimension (feet) Overflow Floor Height Diameter Seminary Hill 1993 4.500 Concrete 417 397 20 203 Davis Hill 1982 2.500 Welded Steel 417 397 20 150 Ham Hill – Tank 1 1982 0.071 Welded Steel 552 469 83 12 Ham Hill – Tank 2 2005 0.230 Welded Steel 552 469 83 22 Cooks Hill 2005 0.760 Welded Steel 531 410 121 33 Source: Table 5-2 of HDR, 2013. 2.3.4 Distribution System 2.3.4.1 Pressure Zones The City’s water system is divided into seven pressure zones, as summarized in Table 2-3. Table 2-3. Pressure Zones Pressure Zone Source Maximum Hydraulic Grade Line (feet) Central Seminary Hill and Davis Hill Reservoirs 417 Ham Hill Ham Hill BPS and Reservoirs 552 Zenkner Valley Zenkner Valley BPS Variable Davis Hill Davis Hill BPS Variable Cooks Hill Cooks Hill BPS and Reservoir 531 Seminary Hill Seminary Hill and Gleason BPS Variable Winterwood Estates Halliday Ridge BPS Variable Source: Table 5-3 of HDR, 2013. Note: BPS = booster pump station 2.3.4.2 Booster Pump Stations Table 2-4 describes the City’s seven booster pump stations and their facilities. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-18 BI1212191438SEA Table 2-4. Booster Pump Stations and Zone Pressure Tanks Pump Station Number of Pumps Pump Characteristics Horsepower Q (gpm) Head (feet) Cooks Hill - Lead Pump 1 5 145 156 - Lag Pump 1 10 145 156 - Fire Pump None Davis Hill - Lead Pump 1 5 50 100 - Lag Pump 2 5 50 160 - Fire Pump 1 25 Ham Hill - Lead Pump 1 5 90 164 - Lag Pump 1 5 90 164 - Fire Pump None Gleason - Lead Pump 1 7.5 75 160 - Lag Pump 1 7.5 Combined 160 - Fire Pump None Seminary Hill - Lead Pump 1 30 250 140 - Lag Pump 1 30 250 140 - Fire Pump Combined Winterwood Estates (Halliday Ridge BPS) - Lead Pump 1 7.5 150 115 - Lag Pump 1 7.5 150 115 - Fire Pump 1 30 Zenkner Valley - Lead Pump 1 7.5 50 200 - Lag Pump 1 7.5 50 200 - Fire Pump 1 25 Pressure Tank Tank Set-Pressures (psi) Pump-On Pump-Off Gleason Road 40 60 Upper Seminary Hill Road 50 70 Source: Table 5-4 of HDR, 2013. Notes: gpm = gallon(s) per minute psi = pound(s) per square inch Q = Flow CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-19 2.3.4.3 Distribution Lines Table 2-5 provides a summary of the distribution system piping present in the water system. The system includes approximately 7 miles of 18-inch transmission piping extending to the City from the old Newaukum River supply. This piping is currently maintained for water that is fed from the system (i.e., not from the Newaukum River) to customers along the line. Table 2-5. Water Distribution Pipe Inventory Pipe Diameter (inches) Asbestos Concrete Ductile Iron Galvanized PVC Total Feet Total Miles 1 2,459 5,258 317 8,034 1.52 2 59,694 11,848 5,044 76,586 14.50 3 381 381 0.07 4 1,112 39,291 216 40,619 7.69 6 6,995 194,352 8,199 209,546 39.69 8 121,391 121,391 22.99 10 2,195 58,072 60,267 11.41 12 89,071 89,071 16.87 16 10,255 10,255 1.94 18 37,868 37,868 7.17 36 470 470 0.09 Total (feet) 10,302 613,304 17,106 13,776 654,488 Total (miles) 1.95 116.16 3.24 2.61 124.0 Source: Table 5-5 of HDR, 2013. 2.3.4.4 Pressure-Reducing Valves The transmission main along Galvin Road, conveying water from the Fords Prairie Treatment Facility to the eastern side of the City, is a high-pressure line. Two distribution lines that come off the Galvin Road transmission main at Sandra Avenue and Lum Road require pressure reductions to provide suitable service to customers. Therefore, two pressure-reducing valves (PRVs) have been installed at these locations. Both PRVs are set with an operating pressure of 100 psi (HDR, 2013). 2.4 Planning Considerations The City’s Comprehensive Plan was developed to meet the requirements of the State of Washington Growth Management Act (GMA), which requires, among other things, consistency between land use plans and utility plans. 2.4.1 Growth Management Act The Washington State Legislature adopted the GMA (and its multiple amendments) in 1990 to guide future development in the state. In 1995, the State Environmental Policy Act (SEPA) rules were amended to require the integration of SEPA documents with the GMA process. The goals of the GMA include the following: 1. Planning for urban growth and reducing sprawl while encouraging citizen participation and coordination 2. Providing for transportation, housing, public facilities, and services to meet planned growth 3. Protecting property rights CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-20 BI1212191438SEA 4. Promoting economic development 5. Providing quality of life by promoting environmental protection, open space and recreation, and historical preservation The GMA mandates comprehensive planning in counties with either large or rapidly increasing populations such as Lewis County. Each county is required to prepare a countywide comprehensive plan consistent with the goals of the GMA, and the comprehensive plan must designate natural resource lands and critical areas. Cities within the county are required to identify and protect their designated critical areas and prepare public facilities plans, which must include the following: • An inventory of existing facilities • Forecasts for future capital needs • Proposed levels of service • Proposed locations and capacities of expanded or new capital facilities • A 6-year plan to finance proposed capital improvements identifying sources of public revenue to be used 2.4.2 Lewis County On December 16, 2013, the Board of County Commissioners adopted the amended Countywide Planning Policies for Lewis County (Lewis County, 2013b). The policies address each of the planning goals cited in the GMA and form the framework from which the Lewis County and City utility elements are developed. The countywide planning policies that specifically pertain to this General Sewer/Facility Plan are as follows: 1. Urban Growth. 1.10 The County and Cities shall collaborate to provide a mechanism for siting and maintaining both existing and new essential public facilities using a 50-year planning horizon for essential public facilities including: (a) Sewage treatment and municipal water facilities 2. Reduce Sprawl. 2.2 Large-scale commercial and industrial development shall be located in designated UGAs, or areas authorized by state law, where adequate utility services and transportation networks are available or planned. 2.3 Water and sewer infrastructure expansion should not occur in areas outside the UGAs and adopted water and sewer district boundaries at urban levels except to address specific health and safety problems. 2.4 Lewis County recognizes that sewer is an urban service. Public sewer extension outside Urban Growth Areas shall be provided at a level of service consistent with state law, and the County’s development standards and comprehensive plan for densities and uses associated with size, scale, and intensity for growth in rural parts of the County. Public sewer connections may be permitted only if hookup sites comply with one of the following situations: A. The Lewis County Health Officer has determined that extension of sewer service is necessary to protect public health and safety. B. The public sewer provides service to existing local and major essential public facilities. C. The public sewer provides levels of sewage collection and treatment necessary to facilitate and support infill development or redevelopment of limited areas of more intensive rural development. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-21 2.6 Developments authorized under Revised Code of Washington (RCW) 36.70A.350, .360, .362, .365, .367 and .368 may be served by urban sewer and water systems consistent with state law. However, no additional connections may be allowed at urban levels of service in the rural area and resource lands between adopted UGAs. 5. Economic Development. 5.9 Lewis County should encourage commercial/industrial development along major transportation corridors and where the potential for expansion of water and sewer development exists consistent with the County Comprehensive Plan and state regulations. 10. Environment. 10.3 Septic systems, disposal of dredge spoils and land excavation, filling and clearing activities shall conform with critical area development regulations and not have a significant adverse effect on Lewis County water bodies with respect to public health, fisheries, aquifers, water quality, wetlands, and fish and wildlife habitat. The Comprehensive Land Use Plan for Lewis County, Washington (Lewis County, 2013a) establishes an overall direction for land use planning in Lewis County and sets guidelines for growth in areas where adequate public facilities and services can be economically provided. The Lewis County Plan does not address zoning for future development, but indicates that individual developments must pay the costs of development. The philosophy of the Lewis County Plan is to provide adequate sewer services for existing development and to provide for future development that will contribute to long-term economic stability in the county. The Utilities Element of the Lewis County Plan identifies the following general and specific goals, objectives, and policies relevant to sewer system development: U GOAL 1 Ensure that necessary and adequate utilities to support development in Lewis County are provided. Policy U 1.1 The County will consult with service providers for the efficient sharing of utility corridors. Policy U 1.2 Ensure adopted County plans, regulations and standards including land use designations and population forecasts are available to utility providers. Policy U 1.3 Utility agreements between the County and utility system providers will provide for the coordination between functional plans and capital facility plans; address the joint use of corridors, installations, and rights-of-way; ensure that development permit reviews address all affected utilities; and mitigate impacts of utility improvement projects. Policy U 1.4 The capability of the land and natural systems will be considered when providing services such as storm water drainage, water supply, and sewage disposal. Policy U 1.5 Encourage the development of alternative energy generation facilities. Policy U 1.6 Coordinate land use and facility planning to allow siting and construction of utility distribution lines within new rights-of-way or where roads which are being constructed or reconstructed in existing right-of-way. Policy U 1.7 The County will cooperate with cities and utility providers within designated subareas to form regional utility organizations appropriate to serve local needs when feasible. Policy U 1.8 The County shall plan, design, and operate public utilities in order to protect public health and safety; comply with appropriate state and federal laws; and accommodate the demands of growth consistent with adopted land use designations and zoning. The County shall cooperate in the regionalization of utility provisions, consistent with financial and resource capabilities. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-22 BI1212191438SEA U GOAL 3 Develop an efficient system of wastewater collection and treatment facilities to support urban growth within designated UGAs. Policy U 3.1 The extension of sanitary sewer services to those areas where onsite sewage disposal systems have created known pollution or health hazards as determined by the appropriate regulating local, State, or Federal agency will be given priority over other extensions. Policy U 3.2 The County should consider alternative techniques or innovative systems for sewage and biosolids disposal. Policy U 3.3 Sewer lines will not be extended into rural areas except to remedy documented groundwater contamination problems or to correct documented existing or impending health hazards. 2.4.3 City of Centralia The Centralia Comprehensive Plan was published in December 1999 and amended in October 2007. The Comprehensive Plan is currently being updated. It was developed to serve as a generalized land use policy for the City over a 20-year planning period. The purpose of the Utilities Element in the City Comprehensive Plan is to confirm that utility services will be consistent with the plan and support the growth anticipated over the next 20 years. This General Sewer/Facility Plan was developed to comply with the following pertinent policies for water/wastewater utilities under the Utilities Element Goals and Policies Section of the City Comprehensive Plan: Goal U 1 To manage all utility growth throughout the city and urban growth areas. Policy U 1.1 Consider impacts on future City development and land use patterns due to the timing and location of new facilities and existing facilities improvements. Policy U 1.2 Facilitate the development and maintenance of all utilities at the appropriate levels of service to accommodate the City of Centralia’s projected growth. Policy U 1.3 Encourage the joint use of public facilities. Policy U 1.4 Recover costs related to the extension of services, as well as the costs of maintain and operate these systems. Policy U 1.5 Encourage extension of utilities to mitigate existing or potential environmental problems. Policy U 1.6 Require all utility design and construction to comply with the City’s accepted Public Works Standards and/or adopted Development Guidelines. Policy U 1.7 Operate, maintain, repair, replace and improve the water, wastewater, stormwater and other utility systems’ infrastructure and facilities, in a manner that provides protection to public health and the environment; protects the infrastructure, facilities and system; corrects deficiencies; increases system efficiencies; and is in compliance with federal, state and local regulations. Policy U 1.8 Review, at regular intervals, the City’s utility plans and utility finances to ensure utility revenue and funding sources are sufficient to provide for the utility systems' operation, maintenance, repair, replacement and improvements. Goal U 2 To use public right-of-ways within the city and the adopted Urban Growth Areas for utilities wherever possible (i.e., water, sewer, communications, electric, stormwater, natural gas, etc.). Policy U 2.1 Maintain public rights-of-way for existing and/or planned utilities. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-23 Policy U 2.2 Require effective and timely coordination of all public and private utility trenching activities. Policy U 2.3 Encourage utility providers that work in public rights-of-way to coordinate and install facilities in the common utility trenches. Goal U 4 To encourage home owners to connect to the City’s sewer system. Policy U 4.1 Allow existing single family homes with septic systems to continue to utilize septic systems, providing there are no health or environmental problems and there is no city sewer line in the vicinity. Policy 4.2 Require all developers and/or benefiting property owners to be responsible for funding the planning, installation, and possible upgrade of sewer system. Goal U 5 To plan and develop water and sewer systems to complement the land use plan. Policy U 5.1 Size sewer system improvements to accommodate for at least a 25-year life cycle as per the uses shown in the comprehensive land use plan. 2.5 Land Use 2.5.1 Current Land Use and Zoning This section summarizes the land use and zoning of the sewer study area. Title 20 of the CMC contains the City's zoning ordinance. The primary intent of this ordinance is to facilitate orderly growth and development of the City, consistent with the policies, goals, and objectives of the City Comprehensive Plan. Pursuant to this intent, all lands within the City have been assigned a zoning district. The zoning ordinance contains regulations that specify land uses permitted in each of these districts. Table 2-6 lists the zoning districts and the UGA acreage assigned to each district according to the City Comprehensive Plan. Table 2-6. Zoning Districts within the City’s UGA – 2006 Zone Zone Description Acres Percentage of Total UGA Acres LCR Lewis County 1 unit per 5 acres 3,609.49 35.55 R1 Low Density Residential 2,565.22 25.26 R2 Moderate Density Residential 390.19 3.84 R3 Medium Density Residential 546.49 5.38 R4 High Density Residential 411.89 4.06 LBD Limited Business District 15.20 .15 C-1 General Commercial 837.91 8.25 C-2 Highway Commercial 144.15 1.42 C-3 Core Commercial 42.20 .42 H-1 Health Services District 61.44 .61 M-1 Light Industrial 528.64 5.21 M-2 Heavy Industrial 709.06 6.98 PMP Port Master Plan 292.59 2.88 Total 10,154.48a Source: City of Centralia, 2007. a The land within the City limits is 4,927 acres, leaving 5,227 acres in the UGA and Lewis County. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-24 BI1212191438SEA In unincorporated regions of Lewis County, the Lewis County Plan guides land use activities. Under the plan, the Fords Prairie area has been assigned an urban land use designation. This designation provides for urban levels of service and development. Areas of unincorporated Lewis County with the urban designation are either currently served by both Class I public water systems and sanitary sewer systems or are within the identified future service areas of such utility systems. Lewis County has not adopted a zoning ordinance; therefore, this area is not zoned for any specific land use. Several parcels within the UGA were annexed by the City. Some of the annexed parcels are owned by the Port of Centralia. As a local government body, the Port has its own master plan to guide land use activities in areas within its jurisdiction. When these Port-owned parcels were annexed, the City adopted the Port Master Plan into its Comprehensive Plan. As the Port identifies potential businesses to locate in the City, the sewer utility coordinates with the Port to determine the impact of additional wastewater discharges to the City's sewer facilities. The study area boundaries for this General Sewer/Facility Plan encompass land within the City's UGA, as described in the City Comprehensive Plan and shown on Figure 2-7. The Land Use Designation shown in this figure was provided by the City in August 2016. The boundaries of the areas studied to locate major pump stations and sewer lines are also shown. The study areas included the following: • Ford’s Prairie • Cook’s Hill • Waunch Prairie/Davis Hill • Widgeon Hill • Former City Golf Course The evaluation for Waunch Prairie/Davis Hill was limited to areas adjacent to Reynolds Avenue and Pearl Street and did not include the very low density residential area on Davis Hill. A proposed development that would use grinder pumps in order to lift domestic sewage to the collection system was evaluated and is labeled "Golf Course." The land uses and maximum densities shown on Figure 2-7 were used to estimate potential wastewater flows in individual sewers. The following discussion further summarizes zoning and land use within the UGA. UNK F:\CENTRALIA_SEWERWASTEWATER\GIS\MAPFILES\CENTRALIA_SEWER_11X17_LANDSCAPE_ZONING.MXD LH013853 8/5/2016 12:38:10 PM L E W I S C O U N T Y T H U R S T O N C O U N T Y C e n t r a l i a C h e h a l i s §¨¦5 §¨¦5 £¤12 £¤12 UV507 C hehalis River Hanaford Creek Sko o k u m c h u c k R i v e r Hayes Lake Plummer Lake Horseshoe Lake Fort Borst Lake Airport Lake Ford's Prairie Cook's Hill Widgeon Hill Waunch Prairie/Davis Hill Golf Course Data Sources:Esri, NOAA, WSDOT, King County, Lewis County, US Census Bureau, USGS FIGURE 2-7New Sewer Study AreaCity of CentraliaGeneral Sewer/Facility Plan ¯0 0.5 10.25 Miles * Information provided by City of Centralia in 2016. Legend Rail Waterbody City New Sewer Study Area Urban GrowthArea (UGA) County Zoning CBDCommercial GatewayCommercial District General Commercial Highway Commercial LimitedBusiness District High DensityResidential Medium-High DensityResidentia Medium Density Residential Low Density Residential Very Low Density Residential Rural Residential Heavy Industrial Light Industrial Medical/HealthCare Port MasterPlan Open Space/Public Facilities CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-27 2.5.1.1 Ford’s Prairie Land Use Land uses for estimating wastewater flows for Ford’s Prairie are summarized in Table 2-7. Table 2-7. Ford’s Prairie Land Use Zoning Acres Population Equivalents Number of Dwelling Units Commercial 376 15,027 -- Industrial/Light Industrial 259 10,382 -- Low Density Residential 380 -- 1,520 Medium Density Residential 47 -- 3,76 High Density Residential 5 4,718a 80 Total 1,067 30,127 1,976a a Includes all residential densities. 2.5.1.2 Cook’s Hill Land Use It is estimated that there are 780 acres of developable land in the Cook's Hill sewer area. It is all zoned very low density residential, which allows two dwelling units per acre (DU/acre). This allows for up to 1,560 dwelling units (DUs) in the Cook's Hill sewer area. Assuming 2.4 persons per household, the ultimate sewered population would be 3,750 people. 2.5.1.3 Waunch Prairie/Davis Hill Land Use Land uses for estimating wastewater flows for Waunch Prairie/Davis Hill are summarized in Table 2-8. Table 2-8. Waunch Prairie/Davis Hill Land Use Zoning Acres Population Equivalents Number of DUs Commercial 39 1,566 -- Industrial 3 125 -- Very Low Density Residential 450 -- 900 Low Density Residential 393 -- 1,572 Medium Density Residential 35 7,193a 525 Total 920 8,884 2,997a a Includes all residential densities. 2.5.1.4 Widgeon Hill Land Use The Widgeon Hill area is zoned for future residential development. Approximately 70 acres are zoned medium density residential and could include up to 560 DUs and 1,340 people. The remaining 855 acres are zoned very low density residential, which is estimated to be up to 85 percent developable. There is a ridge running through the Widgeon Hill area that divides the northern and southern portions of the site. The northern portion comprises about 40 percent of the developable area and could include up to 580 DUs and 1,390 people. The southern portion comprises about 60 percent of the developable area and could include up to 870 DUs and 2,100 people. 2.5.1.5 Former City Golf Course Land Use This area is developer-specific and will be analyzed as development occurs in this area. CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS 2-28 BI1212191438SEA 2.6 Population – Historical and Projected The population of Centralia increased approximately 13.9 percent from 2000 to 2015 based on the Washington State Office of Financial Management estimates. Growth from 2000 to 2010 was approximately 1.1 percent per year, while growth in the past 5 years has been approximately 0.55 percent per year. The decreased growth rate over the last several years may be a result of the economic downturn that began in 2008. Table 2-9 illustrates the historical population growth, with the years 1890, 1950, and 1990 included for reference. Chapter 3 presents the sewer customer population. Table 2-9. Population Growth of Centralia Year Population 1890 2,026 1950 8,657 1990 12,101 2000 14,742 2010 16,336 2011 16,440 2012 16,670 2013 16,600 2014 16,640 2015 16,790 Note: The historical population represents the population within the City limits. The sources of the historical population are the Washington Office of Financial Management Decennial Census Counts (1890 to 2010) and the Official April 1, 2015, population estimates (2011 to 2015). The population projections for Centralia are presented in Table 2-10. The projected population data were prepared by the City’s planning department in May 2016 and align with the City’s current Comprehensive Plan as required by the Growth Management Act (GMA). The City’s Comprehensive Plan was prepared to be consistent with the GMA and the Lewis County Comprehensive Plan. Table 2-10. Projected Population Year Estimated Population 2020 17,500 2025 18,765 2030 22,535 2035 24,164 2040 26,395 Note: Population projections were provided by the City on May 4, 2016. For this General Sewer/Facility Plan, the 20-year planning period is assumed to be 2016 to 2035, and the improvements are based on 2035. The population projections, along with the existing per capita sewer data presented in Chapter 3, form the basis for determining future sewer requirements for the City’s CHAPTER 2 – SERVICE AREA AND VICINITY CHARACTERISTICS BI1212191438SEA 2-29 wastewater collection system. The projected sewered customer base cannot be estimated since it is unknown what privately owned systems will fail or be converted to the public sewer system. In order to be conservative, the estimated projected City population is assumed to be connected to the public sewer system. CHAPTER 3 BI1212191438SEA 3-1 Flows and Loads This chapter presents an analysis of the existing and projected sewer flows and loads. It also discusses infiltration and inflow (I/I), water conservation, and wastewater system design criteria. A detailed analysis of flow and loading is crucial to the planning efforts of a sewer service provider. When analyzing a wastewater collection and treatment system, the first step is to identify current flow and load values to determine if the existing system can provide adequate service to its existing customers under the most critical conditions in accordance with federal and state laws. A future sewer system analysis identifies projected flows and loads to determine where the system will need to be improved to satisfy future growth while continuing to meet federal and state laws. Flow and load values in a wastewater system are used to determine the size of gravity collection piping, lift station facilities, and force main piping, and the size and type of treatment facilities needed. This information is also used to develop the sewer service provider’s National Pollutant Discharge Elimination System (NPDES) waste discharge permit, which is required by Ecology. Historical flow and load data were analyzed for the City’s sewer system to develop per capita values. Using population projections provided by the City, the per capita values were used to develop planning flows and loads to be used for this study. This process is described in the subsequent sections of this chapter. 3.1 Flows This section describes existing and future base sanitary flows, peaking factors, I/I, and water conservation. 3.1.1 Existing Base Sanitary Flows The total influent flow to the WWTP is made up of untreated residential and light industrial flow. The wastewater generated from the collection system is sent to either China Creek Pump Station or North Port Pump Station. Both pump stations have two force mains that differ in size in order to manage the variation of flows. China Creek Pump Station has a 14-inch and 18-inch force main and three submersible pumps capable of conveying a maximum flow of 10 mgd. The North Port Pump station has 10-inch and 6-inch force mains to convey a maximum flow of 300 gpm. The City’s existing collection system flows were estimated using the WWTP discharge monitoring reports (DMRs) for the 2011 through 2015 period. The 2015 average annual wastewater flow was 1.94 mgd. The 2015 average annual value includes I/I on an average day basis. Additionally, the existing base flow with minimal I/I influences was calculated based on seasonal flow rates when groundwater levels were anticipated to be lowest (July and August). Table 3-1 summarizes the average annual, maximum month, maximum day, and dry weather flows to the WWTP for the 2011 through 2015 period. CHAPTER 3 – FLOWS AND LOADS 3-2 BI1212191438SEA Table 3-1. Existing Average Annual, Maximum Month, Maximum Day, and Dry Weather Flow Rates Year Flow Scenario Flow (mgd) 2011 Average Annual 1.86 Maximum Month 3.82 Maximum Day 6.40 Dry Weather 1.04 2012 Average Annual 2.15 Maximum Month 4.47 Maximum Day 6.69 Dry Weather 1.06 2013 Average Annual 1.52 Maximum Month 4.20 Maximum Day 4.34 Dry Weather 1.02 2014 Average Annual 1.69 Maximum Month 3.99 Maximum Day 6.28 Dry Weather 1.01 2015 Average Annual 1.94 Maximum Month 5.82 Maximum Day 8.67 Dry Weather 0.99 Note: Dry weather flow assumed to occur in July and August. 3.1.2 Peaking Factors Once existing flow rates are measured and defined, projected flow rates can be developed. Projected flows are used to further analyze how well the existing system will perform in the future, and to determine improvements required to maintain or improve system function. In order to establish projected flow scenarios for a sewer system, peaking factors need to be determined for the existing system, which can then be applied to future flow rates. Peaking factors are the ratio of higher flows, such as maximum day flow, to the average annual flow (AAF). Table 3-2 shows the flow rates and peaking factors as measured at the City’s WWTP. Peaking factors for collection system pipes and lift stations are typically based on peak hour flow rates. Peaking factors in the collection system can be greater than those experienced at the WWTP due to the smaller size of the sewer drainage basin feeding the particular collector or lift station. The top 15 highest flows between 2011 and 2015 occurred in November and December of 2015, with the highest maximum day flow of 8.67 mgd occurring on December 10, 2015 after a large, multi-day storm. The highest peak hour flow was 8.99 mgd, also occurring in 2015. CHAPTER 3 – FLOWS AND LOADS BI1212191438SEA 3-3 Table 3-2. Summary of Existing Flows and Peaking Factors Year Flow Scenario Flow (mgd) Peaking Factor (by AAF) 2011 Average Annual 1.86 1.0 Maximum Month 3.82 2.1 Maximum Day 6.40 3.4 Peak Hour 6.47 3.5 2012 Average Annual 2.15 1.0 Maximum Month 4.47 2.1 Maximum Day 6.69 3.1 Peak Hour 7.35 3.4 2013 Average Annual 1.52 1.0 Maximum Month 4.20 2.8 Maximum Day 4.34 2.9 Peak Hour 5.11 3.4 2014 Average Annual 1.69 1.0 Maximum Month 3.99 2.4 Maximum Day 6.28 3.7 Peak Hour 6.86 4.1 2015 Average Annual 1.94 1.0 Maximum Month 5.82 3.0 Maximum Day 8.67 4.5 Peak Hour 8.99 4.6 AAF = average annual flow 3.1.3 Industrial Sources There are two existing minor industrial establishments that discharge to the City’s WWTP. It is anticipated that both of these facilities will remain in the near future. Their permits and associated information are included in Appendix C. The City is unaware of any high strength users that discharge to the City’s WWTP. Lewis County Central Transfer Station (State Waste Discharge Permit ST0006139) The Lewis County Central Transfer Station is a transfer station located in Centralia. Wastewater is generated during the cleaning/washing of the transfer station solid waste loading and unloading area. The maximum day wastewater generated is 340 gpd and is considered a nonsignificant industrial user since the flow is less than 25,000 gpd. Their maximum daily biochemical oxygen demand (BOD) and total suspended solids (TSS) limit is 50 pounds per day with an oil and grease daily limit of 2 pounds per day. The average monthly limits for these constituents is the same. Review of the existing DMRs did not reveal any violations above their permitted limits. Expansion within the planning period is not anticipated for this facility. Sierra Pacific Industries (State Waste Discharge Permit ST0006220) The Sierra Pacific Industries includes a sawmill, planer mill, boiler/kiln complex, seedling cooler, truck shop and main office. Industrial wastewater is produced in boiler operations used to provide steam to the kilns for drying lumber. The reverse osmosis concentrate stream and boiler blowdown water are the CHAPTER 3 – FLOWS AND LOADS 3-4 BI1212191438SEA two streams generated by this facility that are discharged to the City’s WWTP. Domestic wastewater is also discharge from the on-site restroom. The facility is permitted for an average quarterly flow of 13,040 gpd and maximum day flow of 26,880 gpd. The BOD and TSS limits are 300 milligrams per liter (mg/L) maximum day with an oil and grease maximum day limit of 100 mg/L. Review of the existing DMRs did not reveal any violations above their permitted limits. Expansion within the planning period is not anticipated for this facility. 3.1.4 Contributing Jurisdictions There are two jurisdictions that contribute wastewater to the City: Lewis County and the Port of Centralia. The City does not have an interlocal agreement with the Port of Centralia. Most of the Port of Centralia’s property is within City limits or the UGA. The interlocal agreement with the Lewis County is included in Appendix C and provides for water and sewer services within the UGA consistent with City ordinances and regulations. 3.1.5 Future Base Sanitary Flows Future flow rates were calculated for the 2020 (5-year) and 2035 (20-year) planning horizons. Population projections, as shown in Chapter 2, were used to calculate the projected flow rates. A population increase was established over the projected period, which was in turn applied to the estimated existing flow rates for the City. The projected flows at the WWTP were developed using the following assumptions: • The average flow rate per capita for 2015 is approximately 124 gallons per capita per day (gpcd), as shown in Table 3-3. The 2015 average flow rate per capita corresponds with the per capita flow rate average for the 2011 through 2015 period, excluding the per capita flow rate for 2013 (which is significantly lower and considered an outlier). • The 2015 per capita flow rate of 124 gpcd also corresponds to the influent flow as documented on the City’s discharge monitoring reports for the publicly sewered accounts within the City. • For planning purposes, the future flow rate per capita will be 126 gpcd, which is the average over the 2011 to 2015 period. This per capita flow is applied to the projected City population. This is a more conservative approach since the exact future sewered population cannot be determined. Table 3-3. Existing Average Annual Flow Rates and Flow per Capita Year Average Annual Flow (mgd) Sewered Population Average Day Flow per Capita (gpcd) 2011 1.86 14,060 132 2012 2.15 15,570 138 2013 1.52 15,570 98 2014 1.69 15,570 109 2015 1.95 15,570 124 Averagea 126 a 2013 flow not included in average, because it is very low and considered an outlier. Gpcd = gallons per capita day Table 3-4 presents the projected flow rates for the City under average annual, maximum month, maximum day, and peak hour conditions assuming the estimated City population is served by the public sewer system. The pump station improvements identified in this General Sewer/Facility Plan do not CHAPTER 3 – FLOWS AND LOADS BI1212191438SEA 3-5 increase the pumping capacities. Historical peaking factors were used to determine future peak flows. Full system sewer modeling will need to be performed during the next sewer planning cycle. The existing WWTP is currently rated for a maximum month flow of 5.5 mgd, a maximum day flow of 8.6 mgd, and a peak hour flow of 9.3 mgd. The hydraulic capacity of the plant will be exceeded within the planning period, based on the projected flows presented in Table 3-4. It is important to note that these values are conservative in order to plan for the worst-case scenario assuming that 100 percent of the projected City population connects to the public sewer. The City will annually monitor and evaluate flows and loads to determine if population is increasing as outlined in this planning document in order to effectively plan for future improvements. Refer to Chapter 6 for more discussion regarding the capacity evaluation for the WWTP and planning for additional capacity. Table 3-4. Projected Flow Rates Year Estimated Population (City) Flow Scenario Flow (mgd) 2020 17,500 Average Annual 2.20 Maximum Month 5.40 Maximum Day Peak Hour 7.75 8.28 2025 18,765 Average Annual 2.36 Maximum Month 5.79 Maximum Day Peak Hour 8.31 8.88 2030 22,535 Average Annual 2.84 Maximum Month 6.96 Maximum Day Peak Hour 9.98 10.67 2035 24,164 Average Annual 3.04 Maximum Month Wet Weather Maximum Month Dry Weather 7.46 2.1 Maximum Day Peak Hour 10.70 11.44 3.1.6 Infiltration and Inflow I/I is the combination of groundwater and surface water that enters the sewer system. Infiltration is groundwater entering the sewer system through defects in the sewer system infrastructure (such as fractured pipes, leaking manholes, and pipe joints). Inflow is surface water that enters the sewer system from sources such as roof and street drains and leaky manhole covers. Reducing sewer collection system I/I is essential for two purposes. I/I reduction results in a lowered risk of sanitary sewer overflows and reduces the cost of treating wastewater. By reducing I/I sources, the extraneous water that previously occupied the conveyance and treatment system can now be occupied by sewage. This leads to delaying conveyance and treatment projects. A sanitary sewer system must be able to carry the domestic wastewater generated by utility customers and the extraneous I/I that is a part of every sewer collection system. CHAPTER 3 – FLOWS AND LOADS 3-6 BI1212191438SEA The amount of I/I varies with time of year and between years. The amount of I/I present will impact the ability of the sewer system to accept additional flows, as a given trunk sewer might be adequate for dry weather flows but might be surcharged under wet weather conditions. Wet weather surcharging has been observed within the collection system, indicating that these lines are above design capacity under some conditions. Additional monitoring is required to determine the adequacy of the existing collection system for future flows. The monitoring program is discussed in Chapter 5 and includes visual inspections of water surface levels and flow monitoring during wet and dry seasons. Chapter 5 also includes proposed projects to mitigate I/I within the system. The EPA report Infiltration/Inflow, I/I Analysis and Project Certification (EPA, 1985) developed guidelines to help determine what amount of I/I is considered “excessive” and what amount can be cost-effectively removed. The report established I/I flow rates that were considered normal or acceptable, based on surveys and statistical evaluations of data from hundreds of cities across the nation. Based on the criteria set forth in this report, historical flow and precipitation data were analyzed to determine if the system had “excessive” I/I. The subsequent sub-sections discuss the results of this analysis, and detailed tables of the analysis can be found in Appendix D. 3.1.6.1 Inflow The EPA report gives guidelines for determining whether inflow can be classified as non-excessive. Inflow is considered non-excessive if the average daily flow during periods of heavy rainfall or spring thaw (i.e., any event that creates surface ponding and surface runoff) does not exceed 275 gpcd. Between the beginning of 2011 and the end of 2015, peak flows exceeded this threshold about 4.7 percent of the time. Figure 3-1 illustrates the cumulative flow frequency during this period; the largest peak flow was 516 gpcd in December 2015. This storm event recorded 0.58 inch of precipitation on December 1, 2015, with a peak of 1.35 inches on December 8, 2015, followed by several days of record precipitation for the remaining days of December. The WWTP influent flow does respond to large precipitation events occurring over a few days. The City is conducting an I/I study to confirm these results and to locate the affected collection system areas to determine if there are any cost-effective sewer rehabilitation measures to remove excessive inflow. It is important to note that the inflow in the City’s collection system is excessive as defined by the EPA. The City is actively looking for opportunities to reduce inflow by conducting smoke testing, video data collection and other inflow data collection techniques as part of their O&M program. CHAPTER 3 – FLOWS AND LOADS BI1212191438SEA 3-7 Figure 3-1. Cumulative Flow Frequency (2011 to 2015) 3.1.6.2 Infiltration Although it can be difficult to determine how much of the flow is due to inflow or infiltration, peak inflow will generally occur immediately during or just after a significant rain event, while peak infiltration will occur during the high groundwater period that follows prolonged precipitation events. This analysis assumed that the high groundwater period occurred in the spring (March through May). In order for the amount of infiltration to be considered non-excessive as defined by the EPA, the average daily flow must be less than the national average for dry weather flow of 120 gpcd (i.e., a 7- to 14-day average measured during periods of seasonal high groundwater but without appreciable rainfall). Between the beginning of 2011 and the end of 2015, there were three dry weather flow events during suspected high groundwater conditions. Two of these events (May 2013 and April 2014) did not have “excessive” infiltration with average daily dry weather flows of 81 gpcd and 114 gpcd, respectively. The only event that had “excessive” infiltration occurred in late April of 2015 and had an average daily dry weather flow of 131 gpcd. These results indicate that the system does not experience excessive infiltration. 3.1.7 Water Conservation The use of water-conserving fixtures can reduce the total wastewater flow to the sewer system. It has been estimated that conservation measures can reduce per capita wastewater flows by as much as 20 percent. If the water reduction measures are sustained over time, then facilities can be sized to accommodate the smaller flows, saving construction costs. Low-flow fixtures that can be used to reduce wastewater flows are low-flush toilets, low-flow showerheads, high-efficiency washing machines, and, to a lesser extent, faucet aerators. One note of caution when trying to reduce the size of facilities based on water conservation is that the water savings attributed to many of the fixtures tend to decrease over time as the fixture ages or the homeowner chooses not to use or replace the fixture, or both. Before decreasing the size of any wastewater facilities based on long-term conservation savings, a thorough review of successful case studies such as that undertaken by Lacey/Olympia/ Thurston/Tumwater, should be done to provide reassurance that the 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 200 400 600 800 1000 1200 50 100 150 200 250 300 350 400 MoreFrequency Flow (gpcd) Cumulative Flow Frequency (2011 to 2015) Frequency Cumulative % CHAPTER 3 – FLOWS AND LOADS 3-8 BI1212191438SEA savings can be sustained without impinging on the inherent margin of safety allowed for in facility designs. An analysis conducted in the previous Facilities Plan (CH2M, 2000b) estimated that the City could potentially realize a flow reduction of approximately 0.4 mgd to the WWTP with a comprehensive conservation program. However, the cost savings per household as a result of decreased water use was not determined to be cost-effective to justify purchasing the water conservation measures required for residential and commercial retrofits. It was suggested that it may be feasible for the City to investigate flow reduction using low-flow showerheads, because they provide nearly one-third of the flow reduction and are relatively inexpensive. In addition, it is worthwhile for the City to continue monitoring conservation efforts in other communities to determine whether the successful efforts and programs of other utilities can be modified to benefit the City's customers. Currently, the City has adopted the 2012 Uniform Plumbing Code, which outlines water conservation performance standards for all new construction and remodeling involving replacement of plumbing fixtures (Washington State Building Code Council, 2012). 3.2 Loads 3.2.1 Existing Loads The WWTP DMRs were evaluated to determine current wastewater characteristics and influent loads. The annual average influent 5-day biochemical oxygen demand (BOD5) load ranged from 2,699 pounds per day (ppd) (2011) to 3,406 ppd (2013) for the 5-year period of analysis as shown in Appendix E. The maximum monthly average TSS load ranged from 2,408 ppd (2011) to 4,059 ppd (2013). Apparent BOD5 and TSS exceedances in 2012 and 2013 prompted a loading analysis on the plant. This analysis revealed that influent BOD5 and TSS were suspected to be reported higher than actual loadings due to a replaced sampler. After improving air mixing, it is believed that the new sampler is now taking representative samples. Table 3-5 presents the total and per capita loading data for 2015, which is the first full year of data after the influent sampling improvements. Based on a sewered population of 15,570, the plant had an annual average BOD5 loading of 0.177 pound per capita per day (ppcd) and a TSS loading of 0.207 ppcd. The BOD5 value is less than Ecology’s Criteria for Sewage Works Design (Orange Book) criterion of 0.2 ppcd. As shown in Table 3-5, the maximum month BOD5 load was 3,776 ppd and the maximum month TSS load was 3,973 ppd. Based on the City’s currently rated BOD5 loading capacity of 4,400 ppd and TSS loading capacity of 5,000 ppd, the plant is operating at 86 percent of its BOD5 capacity and 79 percent of its TSS capacity. Table 3-5. 2015 WWTP Loading Constituent Flow Scenario Concentration (mg/L) Loading (ppd) Per Capita Loading (ppcd)a BOD5 Average Annual 230 2,764 0.177 Maximum Month 317 3,776 0.243 Maximum Day 349 5,508 0.354 TSS Average Annual 271 3,230 0.207 Maximum Month 366 3,973 0.255 Maximum Day 412 5,486 0.352 a Based on sewered population of 15,570. Notes: mg/L = milligram(s) per liter CHAPTER 3 – FLOWS AND LOADS BI1212191438SEA 3-9 Table 3-5. 2015 WWTP Loading Constituent Flow Scenario Concentration (mg/L) Loading (ppd) Per Capita Loading (ppcd)a ppd – pounds per day ppcd = pounds per capita day BOD = biochemical oxygen demand TSS = total suspended solids 3.2.2 Future Loads Projected loads for the WWTP were calculated based on the existing per capita load for 2015 and were developed using the following assumptions: • The existing BOD5 per capita loading is as follows: – Average annual = 0.177 ppcd – Maximum month = 0.243 ppcd – Maximum day = 0.354 ppcd • The existing TSS per capita loading is as follows: – Average annual = 0.207 ppcd – Maximum month = 0.255 ppcd – Maximum day = 0.352 ppcd • For planning purposes, the projected BOD and TSS loading is based on the projected City population. This is the conservative approach since the future sewered population cannot be determined. The future loads based on the estimated City population are presented in Table 3-6. It is important to note that these values are conservative in order to plan for the worst-case scenario assuming that 100 percent of the projected City population connects to the public sewer. The City will review and monitor flows and loads to determine if population is increasing as outlined in this planning document in order to effectively plan for future improvements. Table 3-6. Projected Loads Year Estimated Population (City) Flow Scenario Projected BOD Loading (ppd) Projected TSS Loading (ppd) 2020 17,500 Average Annual 3,106 3,630 Maximum Month 4,244 4,465 Maximum Day 6,191 6,167 2025 18,765 Average Annual 3,331 3,893 Maximum Month 4,551 4,788 Maximum Day 6,638 6,612 2030 22,535 Average Annual 4,000 4,675 Maximum Month 5,465 5,750 Maximum Day 7,972 7,941 2035 24,164 Average Annual 4,289 5,013 Maximum Month Wet Weather Maximum Month Dry Weather 5,860 5,430 6,160 6,220 Maximum Day 8,548 8,515 CHAPTER 3 – FLOWS AND LOADS 3-10 BI1212191438SEA Table 3-6. Projected Loads Year Estimated Population (City) Flow Scenario Projected BOD Loading (ppd) Projected TSS Loading (ppd) 3.3 Wastewater Design Criteria This section discusses the design criteria applicable to both the sanitary sewer system and the WWTP. Capacity analysis regarding adherence to these criteria are discussed in Chapter 5 (Sewer Collection System Improvements) and Chapter 6 (Treatment Plant Evaluation). 3.3.1 City of Centralia Design and Development Guidelines System design criteria and standards have been developed to confirm that a consistent, minimum level of service is maintained throughout the sewer system and to facilitate planning, design, and construction of sewer system projects. The City has developed Design and Development Guidelines (Guidelines), which were adopted in October 2008 and revised in February 2009 (City of Centralia, 2009). These Guidelines cover criteria for both design plans and specifications and are consistent with the 2008 Standard Specifications for Road, Bridge, and Municipal Construction prepared by the Washington State Department of Transportation and the American Public Works Association (WSDOT and APWA, 2008). The Guidelines also state that sanitary sewer work must conform to Ecology requirements. The Guidelines can be accessed on the City’s website at http://www.cityofcentralia.com/Page.asp?NavID=30. 3.3.2 Criteria for Sewage Works Design The Criteria for Sewage Works Design (Orange Book), was originally published in 1978 and revised in 2008 (Ecology, 2019). It guides the design of sewage collection, treatment, and reclamation systems for municipal design engineers and consulting engineers. Table 3-7 provides a summary of design criteria as presented in Table G2-1 of the Orange Book. It is important to note that the Orange Book contains additional design criteria not included in Table G2-1 of the Orange Book. Table 3-7. Design Criteria Summary Unit Processes Flow (F) Organic or Solids Loading (L) Effluent Standards Which Determine the Applicable Design Flows & Loadings All plant pumping, conveyance channels, pipes, and flow structures PIDF N/A N/A Primary and secondary clarifiers 1200 g/sf/day at PHDF + recirculation flow for overflow rate and weir loading rate. PHDL (total suspended solids loading rate to clarifiers)a N/A Biological reactor MWDF MWDL (BOD5 loading to reactor[s])a Secondary treatment and/or nutrient removal and/or reuse MDDF MDDL (BOD5 loading to reactors)a Toxics removal and/or reuse Aeration equipment for substrate removal N/A PHDL (BOD5 and for nitrifying systems, TKN loading rate to biological reactor[s])a N/A CHAPTER 3 – FLOWS AND LOADS BI1212191438SEA 3-11 Table 3-7. Design Criteria Summary Unit Processes Flow (F) Organic or Solids Loading (L) Effluent Standards Which Determine the Applicable Design Flows & Loadings Plant liquid stream pumping equipment PIDF N/A N/A Filters/screens used in the liquid stream for secondary clarification Pass all flows N/A N/A Filters used for secondary effluent polishing Pass all flows requiring tertiary treatment N/A Secondary treatment and/or nutrient removal and/or toxics removal and/or reuse Equalization basins/surge basins Continuous flow routing analysisb N/A N/A Primary and secondary sludge wasting equipment N/A MDDL (BOD5 and TSS loading to primary clarifiers and/or biological reactor[s])a N/A Sludge digestion and dewatering equipment N/A MDDL (BOD5 loading to reactor[s])a N/A Disinfection (non-reuse & non- reliability class I plants) MDDF (for disinfection requirements, PHDF (for hydraulic considerations) N/A N/A Disinfection (reuse & reliability class I plants) All flows N/A Reuse, shellfish harvest protection a Organic or solids loading parameters are to be computed with the same time intervals as hydraulic loadings. b Continuous flow routing analysis to insure the discharge from the equalization basin does not exceed the hydraulic design limit for the downstream unit processes. Notes: g/sf/day = gallons per square foot per day PIDF = peak instantaneous design flow PHDF = peak hour design flow MWDF = maximum week design flow MDDF = maximum day design flow TKN = total Kjeldahl nitrogen CHAPTER 4 BI1212191438SEA 4-1 Existing System The facilities within the City's existing sewer system are described in this chapter. Figure 4-1 presents a schematic of the wastewater collection system, including lift stations, force mains, collection system, and the WWTP and outfall. 4.1 Collection System The City's sewer collection system contains 70 miles of gravity pipelines ranging in diameter from 6 inches to 26 inches. Table 4-1 presents an inventory of the City's existing sewer pipelines. Appendix F includes the existing sewer maps and manhole tables. Table 4-1. Gravity Sewer Inventory Diameter (inches) Concrete (feet) Asbestos Cement (feet) Polyvinyl Chloride (feet) HDPE (feet) Vitrified Clay (feet) Ductile Iron (feet) 6 1,962 178 75 8 87,986 12,257 139,443 1,483 25,614 712 10 6,392 2,819 32,585 529 2,572 12 2,319 16,478 337 14 1,561 12 15 12,531 16 850 18 516 6,451 21 5,390 24 1,209 4,924 26 752 Total 100,384 15,254 217,877 3,614 30,084 724 Note: HDPE = high-density polyethylene As discussed in Chapter 2 of this General Sewer/Facility Plan, the City's original sewer system was constructed using clay pipe over 80 years ago. At the time of construction, clay pipe was installed using short lengths of pipe and no gaskets at the joints. These factors contribute to leaking conditions. Currently, clay pipe represents over 10 percent of the entire collection system. Concrete was the predominant pipeline material used from the mid-1920s to 1970. Before 1965, the concrete pipe was also not gasketed and tends to leak at the joints. Concrete pipe installed prior to 1965 represents over 35 percent of the collection system. Infiltration through the joints in wet weather (which also contributes to inflow) is a major issue of concern for the City. High groundwater, combined with the aging pipe and ungasketed joints, is believed to be a major contributor to the problem. Capital improvement projects ES-1 and ES-4 have been scheduled to address the broken and cracked joints on these older sewer lines. Other than grease buildup in a few localized areas and I/I, the City has very few problems with the collection system beyond those described here. CHAPTER 4 – EXISTING SYSTEM 4-2 BI1212191438SEA 4.2 Pump Stations The sewer system includes 25 pump stations as shown on Figure 4-1. Table 4-2 provides an inventory of the pump stations in the Centralia sewer system and the year of the most recent rehabilitations or pump replacements. Many of the pump stations were installed to serve individual developments. The City strives to serve areas by gravity as much as possible. Pump stations are allowed as an interim solution for individual developments until the development can be connected to the municipal sewer system. Table 4-2. Pump Station Inventory No. Pump Station Type Initial Install Most Recent Rehab./ Pump Replacement No. of Pumps Pump Size (hp) Pump Capacity (gpm) 1 Borst Park W/D 1979 2009 2 30 1,100 2 Mt. Vista W/S 1982 2009 2 1.5 150 3 China Creek W/S 2004/11 2011 3 289.5 1,100-4,500 4 Eshom W/S 1982 2012 2 15 250 5 Galvin/Scheuber W/S 1982 2007 2 20 560 6 Industrial Drive W/S 1978 2005 2 1 80 7 Jensen W/S 1981 2011 2 2.5 150 8 High Street W/S 1959 2010 2 5 200 9 Reynolds W/S 1983 2012 2 7.5 250 10 Marion P 1987 Motor #1 2012 2 3 100 11 State W/S 1985 2004/2009 2 1.5 80 12 Salzer W/S 1992 2001 2 7.5 115 13 Floral W/D 1970 1998 2 7.5 350 14 Ace Auto (Gold #2) W/S 1970 2016 2 3 140 15 Fairgrounds (Gold #1) W/S 1970 2012 2 5 120 16 South Tower W/S 1978 2010 2 1.5 80 17 Van Buren W/S 1953 2008 2 3 150 18 Jefferson W/D 1962 2008 2 15 640 19 Long Road W/S 1987 2011 2 7.5 150 20 W. Mellen W/S 1970 2012 2 10 285 21 Military W/S 1970 2010 2 7.5 100 22 Scammon Creek W/S 1987 2010 2 7.5 200 23 Highland Park W/S 1994 2007 2 5 150 24 North Tower W/S 1999 2012 2 7.5 250 25 North Port W/S 2007 ORIGINAL 2 7.5 300 Notes: hp = horsepower P = package pump station Rehab. = rehabilitation W/D = wet well and dry well W/S = wet well, submersible pump Borst Park, Floral, Jefferson, and West Mellen pump stations have a dedicated backup power source. The remaining pump stations share a 100-kilowatt portable generator. Historically, this generator appears to be adequate for the City. CHAPTER 4 – EXISTING SYSTEM BI1212191438SEA 4-5 4.3 Force Mains Each of the pump stations discharge to the gravity sewer system via a force main. The City's sewer system contains about 19 miles of force mains ranging in size from 2.5-inch-diameter to 18-inch- diameter. Table 4-3 presents an inventory of the system force mains based on mapping provided by the City. Table 4-3. Force Main Inventory Size (inches) Length (feet) Material Less than 3 6,365 Polyvinyl chloride 3.0 2,850 Polyvinyl chloride 4.0 1,209 Asbestos cement 3,756 Ductile iron 3,111 Polyvinyl chloride 6.0 1,838 Asbestos cement 13,358 Polyvinyl chloride 8.0 2,753 Asbestos cement 4,798 Polyvinyl chloride 10.0 2,773 Asbestos cement 4,041 Ductile iron 7,452 Polyvinyl chloride 14.0 3,454 Ductile iron 19,774 Polyvinyl chloride 18.0 3,442 Ductile iron 19,762 Polyvinyl chloride Total 100,736 4.4 Flood Events and the Collection and Conveyance System The City experienced a large storm in December 2007 that resulted in flooding in areas of the City. The City received 8.3 inches of rain over three days with 3.4 inches of rain each day for two of the days. The total rainfall for the month of December 2007 was 16.9 inches with maximum day flows of at or near 8 mgd for four days. The areas affected during these several rain events included: • Harrison Avenue east of I-5 including Eckerson, High, Lowe and Bridge Streets. All of the manholes were covered with water during this event. The High Street Pump Station that serves this area was able to pump after power was energized to the station. • Long Road and South Street between I-5 and the railroad tracks. All of the manholes and Long Road Pump Station were covered with water. The Long Road Pump Station has a sealed hatch lid that prevents water from flowing into the wet well. The station was operational when the power was energized. • South Gold, Grand, Kresky and State Streets. All of the manholes were covered with water. Gold Street #1 and #2 pump stations had water in the panels. Since then, Gold Street #2 has had the panels raised to keep it out of the flood water elevation. Gold #1 has a water tight hatch lid; the panels will be raised within the next few years. The State Street Pump Station has had the panels raised out of the flood water, the lid is bolted down and pick holes are sealed during a flood event. All the manhole frame and lids on South Gold have been modified to locking and sealing lids. CHAPTER 4 – EXISTING SYSTEM 4-6 BI1212191438SEA • Jefferson, Woodland, Jackson and Goff Streets. All of the manholes were covered with water. The Jefferson Pump Station had water in the dry well due to sump pump failure. The station is now equipped with redundant sump pumps and the station is tarped and sand bagged before a potential flood event. • Borst Park Pump Station is tarped and sand bagged to prevent water from entering the dry well. The on-site generator is elevated above the flood waters and this practice seems to control the flooding at the station. The City has flooding event management practices in place as part of their flooding protocols. These practices have served the City well for several years; no further improvements are required at this time. 4.5 Sewer Overflows The City is served by a sanitary sewer collection that is classified as a separate system. The original separate system overflow gates were sealed in the early 1980s; therefore, no controlled overflow locations remain. Known overflows after January 2006 are as follows: • On November 19, 2006, approximately 1,260 gallons seeped out of a faulty pipe joint in the 2600 block of Harrison Avenue. The overflow lasted for approximately 1 day, and the joint was repaired. • On December 26, 2012, level sensor operation failed at the China Creek pump station during a higher than average rain event. Following correction of sensor operation, debris typical to wastewater was found at two unfinished manholes that were part of a Washington State Department of Transportation (WSDOT) construction project near Lakeshore Drive at I-5 and at China Creek Pump Station. No discharge from the sanitary sewer system was witnessed, and no standing water or ponding was observed. The affected area was treated with hydrated lime to minimize odors and to stabilize residuals left behind. • On September 5, 2013, a line exfiltrated into the surrounding soil. Staff did not witness any flow; however, there was evidence of sewage flow on the ground. An unknown amount of flow reached China Creek. • On October 20, 2013, an overflow occurred in the Reynolds Road force main on Pearl Street under the Skookumchuck Bridge. The force main was broken at the air release valve, and an unknown volume of wastewater entered the Skookumchuck River. The pipe has been repaired. 4.6 Wastewater Treatment Plant 4.6.1 Liquids Treatment Processes Construction of the Centralia WWTP was completed in March 2004. Centralia WWTP replaced a WWTP located north of Mellen Street on the eastern side of the Chehalis River. The treatment plant includes screening, grit removal, activated sludge aeration basins, secondary clarifiers, and UV disinfection prior to discharge to the Chehalis River through a multi-port diffuser at river mile 61.25. Solids processing includes belt filter press dewatering of activated sludge solids and aerated static pile composting. The City also has the ability to use lime pasteurization as a backup processing alternative. The process schematic is shown on Figure 4-2. 7 6 9 SECONDARY SCUMP PUMPS BIOSOLIDS STORAGE FACILITY LANDAPPLICATION EFFLUENT PUMP STATION OUTFALL TO CHEHALIS RIVER PARSHALL FLUME POST AERATION ULTRAVIOLET LIGHTDISINFECTIONRASRAS PUMPING WAS SC U M FLOW SPLITTER BOX WAS RAS SHCRAS BIOSOLIDS SLURRY TANK PORTABLE SAMPLER WAS PUMPING AERATION BASINSANOXIC SELECTOR PORTABLE SAMPLERGRIT SEPARATOR 2 MECHANICAL BAR SCREENS ODOROUS AIR TO BIOFILTER RAW SEWAGE HEADWORKS GRIT CYCLONE/ CLASSIFIER FUTURE PRIMARY SLUDGE TO GRIT SEPARATOR AND SOLIDS HANDLING SCREENINGS DUMPSTER GRIT TO DISPOSAL DUMPSTER WAS SCUM SECONDARY SLUDGE TO SOLIDS HANDLING SHC SCUM FLOW STREAM IDENTIFICATION NUMBER SAMPLE LOCATION MAGNETIC FLOW METER PUMP STREAM IDENTIFICATION 1 2 3 4 5 6 FLOW RATE (MGD) RAW SEWAGE MIXED LIQUOR SECONDARY EFFLUENT PLANT EFFLUENT RS ML SE 7 RAS RETURN ACTIVATED SLUDGE MAX. DAY TSS (LBS/D) - - 5.5 5.6 8.34 5.5 5.5 2.74 9.3 9.4 9.3 9.3 5.5 4,200 4,620 209,000 459 459 160,000 4,620 459 459PLE 8 WAS -0.10 - WASTE ACTIVATED SLUDGE DEWATERED BIOSOLIDSDB 14.9 - -5,5300.0044 *ABI AERATION BASIN INFLUENT 5,821 BOD (LBS/D) MAXIMUM MONTH MAXIMUM MONTH MAXIMUM MONTH 17 CY/DAY 7,466CLASS A BIOSOLIDS 3 9 POLYMER FEED PUMP PLANT WATER BELT FILTER PRESS FLOW SPLIT WEIR, TYP S M P M M M M P P P P P SECONDARY CLARIFIERS P P P P P 5 S S S 3 S S 8 P M 5,000 1 M M COMPOSTFACILITY LIQUIDS/SOLIDS BALANCE WWTP IS DESIGNED TO TREAT 9.3 MGD AND HYDRAULICALLY PASS 10 MGD. SOLIDS PROCESSING BASED ON 5-DAY PER WEEK OPERATION. 4 DRY AND LIQUID POLYMER SYSTEM PASTEURIZATION VESSEL THERMOBLENDER BELT WASHWATER PUMP FILTRATE TO PLANT DRAIN P SLUDGE TRANSFERCONVEYOR 1 SLUDGE TRANSFERCONVEYOR 2 ODOROUS AIR TO BIOFILTER ODOROUS AIR ODOROUS AIR TO BIOFILTER WET AIR SCRUBBER ODOROUS AIR TO BIOFILTER LIME FEEDER LIME STORAGE SILO 8 PRODUCT TRANSFER CONVEYOR LIME SCREW CONVEYOR CONTRACT MANAGEMENT P Fig 4-2_672413.dgn General Sewer/Facility Plan City of Centralia Figure 4-2 CENTRALIA WASTEWATER TREATMENT PLANT PROCESS FLOW SCHEMATIC CHAPTER 4 – EXISTING SYSTEM BI1212191438SEA 4-9 Influent sewage is pumped to the WWTP by either the China Creek Pump Station or the North Port Pump Station. Both pump stations use twin force mains of different sizes to maintain minimum velocity over the wide range of flows. Magnetic flow meters measure each of the incoming flows at the headworks. Wastewater is first screened through two mechanical quarter-inch-diameter screens with integral brush cleaning and compaction screws. A manual screen is provided in case a mechanical screen is out of service during high flows. Grit is then removed by gravity settling in a detritus grit basin. Grit is pumped through a grit cyclone and classifier to separate the inorganic grit from the organic particles and remove water. The dewatered grit and screenings are collected in dumpsters and periodically hauled by the solid waste company to a landfill. Screened and de-gritted wastewater flows to two aeration basins for activated sludge treatment. Space has been provided between the headworks and aeration basins for future treatment processes or equipment. The aeration basins include anoxic zones where the wastewater is mixed with return activated sludge (RAS). Nitrate in the RAS is used instead of oxygen to remove soluble BOD. The anoxic zone promotes growth of bacteria with good settling characteristics, removes nitrogen, reduces the amount of oxygen required, and produces alkalinity. The mixture, called mixed-liquor suspended solids (MLSS), flows to the aerated portion of the aeration basins where the bacteria remove BOD and convert ammonia to nitrate. The solids retention time is maintained at a long enough duration to provide efficient nitrification (i.e., the conversion of ammonia to nitrate all year round). Aeration is provided by multi-stage centrifugal blowers and fine- and coarse-bubble diffusers with Ethylene Propylene Diene Monomer membranes. Aeration provides oxygen and maintains the MLSS in suspension. The effluent from the settled MLSS flows over the secondary clarifier weirs, and the settled solids are pumped back to the aeration basins by four submersible RAS pumps. There are two circular secondary clarifiers with spiral mechanisms for moving settled solids to the center of the clarifier for removal. The waste activated sludge (WAS), or settled solids, are periodically pumped to the belt filter press for removal. Secondary effluent flows by gravity through three UV disinfection channels. Each channel is equipped with arrays of horizontal UV light tubes that disinfect the secondary effluent by exposure to UV light. The disinfected secondary effluent normally flows by gravity to a multiport outfall for discharge into the Chehalis River. At high Chehalis River flows, gravity flow may not be possible and the secondary effluent is pumped through the outfall using submersible pumps. 4.6.1.1 Biosolids Management The WWTP has two solids processing systems. Aerated static pile composting, constructed in 2013, is the City’s primary method of processing solids with lime stabilization as the backup method. WAS is pumped to the belt filter press for dewatering. Dewatered WAS is mixed with green waste and screened compost oversized material called ‘overs.’ This mixture is placed on a bed of overs and covered with a blanket of overs. The resulting compost pile is aerated by either pulling air through the compost pile or pushing air through the pile using blowers and perforated piping at the base of the compost pile. When air is pulled through the pile, the resulting odorous air is discharged to a compost biofilter for odorous air treatment. The compost piles are made without spaces between individual compost piles to reduce the amount of space required. The compost piles are covered by the biosolids storage building, and the green waste is kept covered to minimize the effect of precipitation. All composting is done on a paved surface, and all runoff is collected and returned to the WWTP for treatment. After composting to achieve sufficient stabilization and temperature to meet EPA Class A biosolids requirements, the composted material is screened. Material passing through the screens is the compost product, and the larger material not passing through the screens is called overs and returned to the process as previously described. The compost product is ‘cured’ by storing in unaerated piles to provide further stabilization before it is tested prior to distribution. Originally, the dewatered WAS was treated in a lime pasteurization system manufactured by RDP. Quicklime (calcium oxide) was mixed with the dewatered WAS and mixed in a thermoblender where CHAPTER 4 – EXISTING SYSTEM 4-10 BI1212191438SEA additional heat was added by electrical resistance heaters. The temperature of the heated mixture was maintained in an insulated box for 30 minutes to produce Class A biosolids. 4.6.1.2 Outfall The existing outfall is 36 inches in diameter with eight 16-inch-diameter outlets designed for a maximum future capacity of 30 mgd. The initial required capacity is 10 mgd. Outfall risers 2, 4, 6, and 8 are equipped with 12-inch-diameter “duckbill” outlets, and the remaining four outlets are installed with blind flanges. The blind flanges can be replaced by 12-inch by 16-inch reducing elbows and duckbill outlets to increase capacity in the future. 4.6.2 Plant Bypass The WWTP has no bypass. 4.6.2.1 Odor Control Odor control is provided by a biofilter located adjacent to the headworks. Since its original construction, the soil in the biofilter was replaced by bark due to plugging issues from the lime pasteurization process. 4.6.2.2 Design Data Plant design data are presented in Appendix G. 4.6.3 Other Facilities The plant has a maintenance facility that includes a maintenance area, laboratory, lunch room, locker rooms, control room, administrative office space, and storage space for chemicals and other supplies. A storage building for collection system equipment and a wastewater decant facility have been added since the plant’s original construction. The collection system storage building is used by collections staff for the eductor trucks and closed-circuit television inspection vehicles and equipment. The decant facility was completed in 2015 and is used to separate the water from material collected during sewer maintenance. This facility has three bays and is enclosed by a three-sided prefabricated metal building. An oil-water separator captures fats, oil and grease (FOG) in the decanted water prior to discharge to the headworks. The facility is located in the southwestern portion of the existing WWTP, adjacent to existing truck access roads and an entrance gate. CHAPTER 5 BI1212191438SEA 5-1 Sewer Collection System Improvements An evaluation of the City's sewer system is presented in this chapter. The evaluation includes proposed future expansions and improvements to the existing system. The existing and future collection systems for basins likely to be impacted by future growth were analyzed. Apparent capacity-related deficiencies were identified with existing flow and pump station telemetry data; and structural and operational deficiencies were identified from staff observations. 5.1 Introduction The objective of conducting a sewer system evaluation is to gain an understanding of the system and its response to various flow conditions. The City has a number of concerns to be addressed within the sewer system, such as service for new development, I/I impacts, prevention of overflows, and compliance with current regulations. A comprehensive system evaluation provides the City with the data needed to make informed decisions for the continued operation and maintenance of the system. 5.2 Collection System Evaluation 5.2.1 Existing Collection System and Flows The following items were developed as part of the 2000 General Sewer Plan: • Base sanitary flows = 76 gpcd • Average annual dry weather flow = 1.5 mgd • Wet weather flow = 6.0 mgd An evaluation of flow data for the 2011 to 2015 period was also completed for this General Sewer/Facility Plan. As presented in Table 3-2, the 2011 to 2015 average dry weather flow is 67 gpcd. This base sanitary flow is lower compared to the 2000 value, but is just marginally lower than the 2011 value. In addition, the average annual dry weather flow is approximately 1.0 mgd (average of the 2011 to 2015 period), which is also lower compared to the 2000 analysis. It is important to note that, although the sewered population has increased by 4,500 people, base flows are lower likely due to water conservation efforts as described in Chapter 4. Additionally, as presented in Table 3-1, the maximum day flows are approximately 6.5 mgd, slightly higher than the wet weather flow identified in the 2000 General Sewer Plan. For planning purposes, the results and assumptions used in the previous sewer plan are considered valid and carried forward in this General Sewer/Facility Plan when no additional data exist. A hydraulic model of the City’s collection system was not completed for this General Sewer/Facility Plan. The existing collection system is assumed to be adequate for existing flows. There have been no sewer backups or overflows reported by City staff. Collection system deficiencies are generally related to component age. The initial collection system installed in the early 1900s was constructed of ungrouted clay pipe in lengths of 3.5 to 8 feet. Concrete sewer pipe laid prior to 1965 was typically ungasketed pipe in similar lengths. These construction techniques have historically resulted in pipe sections that are prone to infiltration in high groundwater conditions. Approximately 142,000 feet of clay and concrete pipe were installed prior to 1965. The recommended improvements to resolve this aged piping are included in Section 5.7. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-2 BI1212191438SEA 5.2.2 Surcharging of Existing Trunk Sewers The existing collection system has surcharged during wet weather conditions. City staff have conducted several visual surveys of manhole water levels during wet weather and dry weather conditions. It is desirable for the water level in the manhole to remain at or below the crown (top) of the trunk sewer pipe that enters and leaves the manhole, although minor surcharging is not unusual. During the dry season, the sewer pipes are flowing less than full, which indicates that the existing collection system has adequate capacity for dry weather flows. Average annual WWTP flows are less than 80 percent of the design average annual flow. The fall season data indicate that the water level in the trunk sewers increases as the WWTP flows increase and as the Chehalis River rises. Surcharging is occurring in downtown trunk sewers No. 1 and 2 and Jefferson. The most significant surcharging is occurring in the deepest sections of the downtown sewers. It is important to note that the level of surcharging within the downtown trunk sewers is directly correlated to the WWTP flow and the Chehalis River elevation. The City has completed several I/I rehabilitation projects that replaced old leaky pipes and has observed reduced surcharging in these areas. Manhole monitoring was undertaken in the Jefferson and Long pump station areas during wet weather conditions in February 2014. Figure 5-1 presents the water level in each of the manholes monitored compared to the manhole depth and sewer pipe crown and invert (bottom) for February 19, 2014. Peak flow to the WWTP on this date was 5.66 mgd, and the Chehalis River flow was 26,000 cubic feet per second (cfs) at Grand Mound. The results show that at this flow and river flow, the existing system can be surcharged and used as storage. 5.2.3 Projected Development Flows Projected future wastewater flows are used to define the required collection system improvements and extensions that will be required to accommodate growth within the sewer service area. Peaking factors are added as a flow component to account for the diurnal flow variation within a basin over the course of day and is based on dry weather flow monitoring data. Since there is limited flow monitoring data, diurnal curves developed by the Unified Sewage Agency in Hillsboro, Oregon, were used to characterize the diurnal characteristics of the basin. These curves are based on an extensive flow monitoring program conducted from 1989 to 1992, which resulted in a series of dimensionless unit diurnal flow curves that are characteristic of basins containing certain land uses. The flow curves were based on a linear regression analysis of data from 126 flow monitoring sites. The nonresidential peaking factor was derived from this data. The saturation population of the 20-year Urban Growth Boundary areas was calculated based on projections in the Centralia Comprehensive Plan of 6.73 DU/acre, 2.4 people per DU, and the acreage of land available for development. Nonresidential flows were estimated using a peaking factor of 2.83 and the developable acreage. The flow estimates from each area assume maximum development. The flow estimates for all the urban growth areas cannot be added, as the total flow would be greater than that which would result from the projected 20-year growth. This analysis technique provides a conservative analysis of the potential impacts on the existing system, if the maximum possible population growth occurred in an urban growth area without redevelopment. Table 5-1 summarizes the projected peak sewage, I/I at 2,500 gpcd, and total wet weather flows for each of the urban growth areas. These areas are coded NS, as new sewers would be required to serve these areas. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-3 Figure 5-1. Existing (2014) System Surcharging Table 5-1. Projected Peak Flows within UGA New Service Areas Peak Sewage (mgd) I/I (mgd) Total (mgd) NS-1 South Port Industrial 0.23 0.15 0.38 NS-2 North Port Industrial 0.23 0.15 0.38 NS-3 East Port Industrial 0.11 0.08 0.19 NS-4 Ives Road Industrial 0.06 0.04 0.09 NS-5 Cooks Hill Residential 0.42 .017 0.437 NS-6 East Waunch Prairie Industrial 0.42 .017 0.437 NS-7 Fords Prairie Residential 0.53 0.15 0.68 NS-8 South Centralia Residential 0.18 0.06 0.24 NS-9 Kresky Residential/Commercial 0.13 0.05 0.18 NS-10 South Ham Hill Residential 0.01 0.04 0.05 NS-11 Logan District Residential 0.01 0.03 0.04 NS-12 Reynolds Road Commercial 0.04 0.01 0.05 NS-13 North Centralia Industrial 0.62 0.42 1.04 NS-14 Taylor/VanWormer Residential 0.07 0.03 0.10 NS-15 Graf Road Residential 0.19 0.08 0.26 NS-16 Lum Road Industrial 0.05 0.09 0.14 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-4 BI1212191438SEA Included in this evaluation are parcels in the UGA that are currently being served by a septic system but that have potential to be served by the municipal sewer collection system in the vicinity. These new unsewered areas are separate from the areas presented in Table 5-1. As the septic system fails, that parcel will need to connect to the City’s municipal collection system. Sewage flows from the unsewered areas (US) were estimated based on a house count and assuming 2.4 people per DU. Table 5-2 summarizes the projected peak sewage, I/I, and total wet weather flows for each of the unsewered areas. Table 5-2. Projected Peak Flows in Unsewered Communities Unsewered Areas Peak Sewerage mgd I/I mgd Total mgd US-1 West Edge of Cook’s Hill Residential 0.02 0.01 0.03 US-2 South of Cook’s Hill Residential 0.003 0.001 0.004 US-3 East of Plummer Lake Residential 0.01 0.01 0.02 US-4 Ham Hill Residential 0.06 0.02 0.08 US-5 North of Meridian Avenue Residential 0.02 0.01 0.03 US-6 Waunch Prairie Residential 0.23 0.09 0.32 US-7 Fords Prairie Residential 0.02 0.01 0.03 US-8 Scammon Creek Residential 0.009 0.004 0.013 The flows from each of the UGAs and the unsewered areas were allocated to the basin most likely to receive those flows. Table 5-3 summarizes the estimated sewer main capacity and estimated proposed peak sewage flows for each sewer main based on the allocation of future flows. As noted in Section 5.2.1, the base and average annual dry weather flows have not significantly increased over the last several years, but a collection system evaluation was not completed as part of this General Sewer/Facility Plan. As future development occurs, a comprehensive downstream collection system evaluation is mandatory to determine the effects from the point of connection to the WWTP of that development. This collection system evaluation is the responsibility of and will be prepared by the developer and reviewed by the City as part of the permit application process. Table 5-3. Evaluation of Potential New Flows on Sewer System Capacity (Peak Sewage Flow Only) Trunk Sewer Identification Pipe Size Estimated Capacity (mgd) Potential New Flow Unsewered Communities (mgd) UBG Areas (mgd) Total New Flow (mgd) Downtown No. 1: Central Boulevard to Creekside Court 10-inch 0.8 0.06 -US-4 0.06 G Street to Central Boulevard 12-inch 1.2 0.04 0.1 First Street to G Street 15-inch 1.5 - 2.2 0.1 Plum Street to First Street 18-inch 3.3 - 4.0 0.01 -US-3 0.11 WWTP to Plum Street 24-inch 6.0 - 6.3 0.11 Downtown No. 2: Oak Street to Hanson Street 14-inch 1.0 - 1.6 0 Pear Street to Oak Street 15-inch 3.3 0 Courtland Street to Pear Street 18-inch 6.0 - 8.0 0 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-5 Table 5-3. Evaluation of Potential New Flows on Sewer System Capacity (Peak Sewage Flow Only) Trunk Sewer Identification Pipe Size Estimated Capacity (mgd) Potential New Flow Unsewered Communities (mgd) UBG Areas (mgd) Total New Flow (mgd) Downtown No. 3: Oak Street to N. Pearl Street 15-inch 3.3 0 Mellen to S. Cooks: Military PS to Scheuber Road 8-inch 1 .003 -US-2 0.003 Mellen to N. Cooks: Mellen PS to Cooks Hill Landing 8-inch 0.8 - 1.0 0.02 0.49 - NS-5 0.51 Waunch Prairie: Reynolds PS to Roanoke Street 12-inch 1.5 0.23 -US-6 0.23 Eshom to S. Port: Midway Court to S. Gallagher Road 8-inch 0.6 0.45 - NS-1 0.45 Eshom PS to Midway Court 10-inch 1.3 -1.7 0.06 -NS-4 0.51 0.02 - NS-3 0.53 0.03 - NS-2 0.56 Eshom to N. Port:a Galvin Road to N. Gallagher Road 10-inch 1.5 - 1.8 0.45 - NS-1 0.45 Eshom PS to Galvin Road 10-inch 1.3 - 1.9 0.06 - NS-4 0.51 0.02 - NS-3 0.53 0.03 -NS-2 0.56 Scammon to W. Cooks: Stillwater Estates 10-inch 0.9 - 1.9 0.02 0.02 Scammon PS to Stillwater Estates 12-inch 1.6 - 3.5 0.49 -NS-5 0.02 Scammon PS to Stillwater Estates 12-inch 1.6 -3.5 0.49 -NS-5 0.51 Borst Park to Borst Avenue: Borst PS to Borst Avenue 12-inch 1.1 0.02 -US-7 0.53 - NS-7 0.53 0.06 -NS-4 0.59 0.02 -NS-3 0.61 0.03 -NS-2 0.64 0.45 -NS-1 1.11 Eshom to Fords Prairie: Eshom PS to S. Scheuber Road 8-inch 0.5 0.26 -NS-7b 0.26 WWTP and Long: E. Borthwick Street to Long PS 10-inch 0.8 0.18 0.48 W. Borthwick Street to E. Borthwick Street 8-inch 0.5 0.18 W. Borthwick Street 10-inch 0.8 0.18 WWTP to W. Borthwick Street 18-inch 2.9 0.18 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-6 BI1212191438SEA Table 5-3. Evaluation of Potential New Flows on Sewer System Capacity (Peak Sewage Flow Only) Trunk Sewer Identification Pipe Size Estimated Capacity (mgd) Potential New Flow Unsewered Communities (mgd) UBG Areas (mgd) Total New Flow (mgd) Jefferson to Basin 6: Railroad to Main 15-inch 2.2 - 2.6 0 Pearl Street to Railroad 30-inch 13.4 - 7.5 0 Jefferson PS to Pearl Street 18-inch 3.4 0 a Does not include industrial flows from bottling plant. b Represents 1/2 of NS-7 projected peak sanitary flow. Notes: -- = not applicable flows NS = New Sewer PS = pump station US = Unsewered Communities Conceptual sewer system layouts were developed to respond to the identified capacity needs in each area of the City where sewer service does not currently exist or where new growth will require the extension of service. Existing collection system improvements were identified based on information from City staff and an evaluation of the age and pipe type of the gravity collection system. As new development occurs, a detailed analysis of the affected collection system sewer pipes will be required to confirm adequate capacity under average and peak flow scenarios. A hydraulic system model would be a valuable tool to assist the City to evaluate the impacts of such developments. As previously noted, a collection system evaluation was not completed for this General Sewer/Facility Plan Update. The areas of growth have mostly occurred or will occur in the proposed development areas (Section 5.2.4). These areas were studied to determine the collection system improvements required to serve these areas. As development occurs in these five areas, the impacts to the downstream collection system will need to be carefully evaluated and assessed to determine existing collection system improvements. 5.2.4 Proposed Development Areas Over the last several years, a number of development areas were proposed and were reviewed for sewer availability and the improvements required to serve these areas. These areas include the following: • Ford’s Prairie • Cook’s Hill • Waunch Prairie/Davis Hill • Widgeon Hill • Former City Golf Course The results of these evaluations are included in this chapter. Additional sewers must be constructed if the City chooses to provide sewer service either to unsewered residences within the City limits or to areas within the 20-year UGA. The flows associated with each area evaluated are summarized in each growth area section. Flows from each of the new identified areas would connect into the existing system to be conveyed to the WWTP. As noted previously, additional developments that will discharge to the City’s collection system and WWTP will need to be evaluated for downstream impacts to verify that capacity is not exceeded. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-7 5.3 Collection System Alternatives 5.3.1 China Creek Interceptor In the summer of 2003, dual force mains of 14- and 18-inch diameter were installed in an existing road along the Chehalis River between the China Creek and Borst Park pump stations. The pipelines were installed in this road, because the areas on either side were classified as wetlands and would have required extensive permits that would have significantly delayed the project. This road has been in this location since 1960. In December 2007, Chehalis River flows reached the maximum on record of 79,100 cfs. After flood waters receded, the controlled density fill surrounding the pipelines was exposed on the river side about 840 feet upstream of the confluence with the Skookumchuck River. Two alternatives were evaluated to address this issue: 1. Riverbank stabilization using riprap to stabilize more of the bank where the pipeline is close to the Chehalis River 2. Relocation of the pipelines away from the Chehalis River 5.3.1.1 Alternative 1 – Riverbank Stabilization (C.I.P. CC-1) The City hired a contractor in May 2008 to perform an emergency repair and place riprap along about 150 linear feet (lf) of riverbank where the pipeline was exposed. The riprap appears to be WSDOT “Heavy/Loose” riprap or larger with a maximum size of approximately 2,000 pounds. It appears that woody debris was embedded into the riprap toe for fish habitat. The riprap appears to have stabilized the intended section of bank, but erosion continues both upstream and downstream of this section. Another flood of 50,700 cfs occurred in January 2009. This alternative involves extending the existing riprap section both upstream (950 lf) and downstream (300 lf) to protect the most threatened sections of pipeline. A riprap volume of 15,000 cubic yards is estimated to be required for this. It is anticipated that riverbank conditions, including existing large trees that may need to be preserved, will mandate that roughly half of this volume will need to be placed by equipment working from the top of the bank, with the remaining volume placed by water-borne equipment. Work done from the top of the bank will have to be done without damaging the existing pipelines. Matting or other methods might be needed to protect the pipelines from concentrated equipment loads during construction. The project is expected to require several federal and state permits and approvals covered by the Joint Aquatic Resource Permit Application (JARPA). Local permits and approvals from the City will also be required. 5.3.1.2 Alternative 2 – Relocation of Pipelines To avoid further exposure of the force mains, the option to relocate the pipelines away from the Chehalis River was also evaluated. The relocated pipes will be located in a new access road to the east of the existing access road for the portion of the roadway where the adjacent riverbank continues to erode. The new road alignment will move the pipelines as far away as possible from the riverbank erosion, without encroaching on the WSDOT right-of-way for I-5. The new road will be located in an existing wetland. This wetland encompasses the entire area between the existing access roadway to the west and the WSDOT property to the east, and cannot be avoided. No excavation will take place in the wetland, and imported fill will be used to build up the road over a layer of geotextile. It is assumed that the roadway will have a 15-foot-wide driving surface, covered with crushed rock. Once the road is completed, the force mains would be relocated and reinstalled in the new roadway. One pipeline will need to remain in service while the other pipeline is moved. Like Alternative 1, this alternative is expected to require federal and state permits and approvals covered by the JARPA, as well as permits and approvals from the City. In addition, compensatory CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-8 BI1212191438SEA mitigation will be required due to the extent of wetland impacts, estimated at about 0.9 acre. The amount of mitigation required will depend on the wetland area impacted and the wetland classification of both impacted and mitigation wetlands, and will be negotiated directly with the regulatory agencies during the permitting process. For the purposes of this evaluation, it was assumed that new wetlands can be created at the City’s WWTP site, although the purchase of wetland credits from a certified mitigation bank may be less costly and involve a shorter timeframe. 5.3.1.3 Costs Class 5 cost estimates were prepared for each alternative, along with an estimate of annual operation and maintenance costs. The costs were originally developed in 2013 dollars then escalated to 2016 dollars using the 20-city average Construction Cost Indexes (CCI) published by Engineering News-Record (ENR). The base construction cost includes mobilization, bonds, contingency, and sales tax. Total project costs were estimated by adding 30 percent to the base construction costs. This additional cost allowance accounts for design, bidding, services during construction, permits, investigations, and legal and administrative services. At this stage, the expected accuracy level of the base costs shown is minus 30 percent to plus 50 percent. These two values were used to develop a 20-year life-cycle cost for both alternatives, as shown in Table 5-4. Table 5-4. China Creek Interceptor Alternatives, Estimated Project and Life Cycle Costs Alternative Base Project Cost Riverbank Stabilization $1,750,000 Relocation of Pipelinesa $3,370,000 a Assumes that new wetlands will be created at the WWTP site. Due to the higher cost and challenges of providing wetland mitigation to relocate the pipeline, the City is no longer considering Alternative 2 and will pursue the option of stabilizing the riverbank with riprap to address the exposure of the China Creek force mains. 5.3.2 Evaluation of Centralia Station Development Providing sewer service to the new Centralia Station Development was evaluated. The development is located within the City’s south sewer area. This area has numerous pump stations that collect and convey sewage to the China Creek PS. Four of the pump stations within the south sewer area (South Tower, Ace Auto, Jefferson, and Van Buren) were determined to require high-priority or near-term improvements under the Task 10 evaluation, “General Sewer Plan Update Task 10: Pump Station Improvements.” Historically, the south sewer system is overloaded by I/I, as documented in the 2000 General Sewer Plan prepared by CH2M. During extreme wet weather events, the surcharging of the gravity sewer system upstream of the Jefferson PS nearly reaches the ground surface. In 2008, the City upgraded the pumps at Jefferson PS in an effort to reduce the level of surcharging in the south sewer system. In 2014 (February 18 to 20), after a significant precipitation event (2.88 inches over 48 hours), the pump station run time (approximately 20 hours a day) showed that the Jefferson PS is still overloaded. Manhole level monitoring indicated there is also surcharging, although much less, in the gravity sewers upstream of the Jefferson PS and in other gravity sewers in the south sewer system. Therefore, there is essentially no capacity for additional flow in the south sewer system, and one of the following two alternatives must be a part of any project to allow new connections: 1. Alternative 1 - Remove I/I to make capacity available for the additional flow being added. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-9 2. Alternative 2 - Increase sewer system capacity by an amount equal to or greater than the additional flow being added. Both alternatives will discharge to an existing 18-inch-diameter gravity sewer that crosses under I-5. The estimated capacity of the undercrossing is 2,600 gpm. The estimated future flow at this location is 1,700 gpm, indicating that the undercrossing has sufficient capacity for either alternative. Manhole observations during high flows on February 18 to 20, 2014, indicated that the system is at capacity with no surcharging observed at the undercrossing. With the projected peak flow increase from the development, approximately 2 feet of surcharge could occur during the highest flows. No adverse impacts are anticipated from the surcharged conditions, and this condition would be the same for either alternative. As a result, it does not affect the comparison of alternatives. Prior to the design of the selected alternative, confirmation of the capacity of the undercrossing should be re-evaluated during wet weather conditions. 5.3.2.1 Alternative 1 The proposed improvements for Alternative 1 are shown on Figure 5-2. Alternative 1 will convey the Centralia Station Development sewage by gravity to the existing system to the maximum extent possible and will include upgrading the existing Long Road PS capacity from 150 gpm to 745 gpm. The northern portion of the development (properties north of the proposed I-5 off ramp) will be able to drain by gravity to the existing 8-inch and 10-inch sewers along Alder Street, with approximately 645 gpm from the development flowing to the Long Road PS. The upgraded pump station will also serve existing properties to the south of the new development. A total of 745 gpm will be conveyed to Long Road PS. The upgraded pump station will include a new 8-inch, 3,100-foot-long force main that will discharge to the existing 18-inch sewer in Borthwick Street. Additional upgrades will include replacement of pumps with larger pumps, upgrading the electrical system, and increasing the capacity of the wet well. This alternative will also include extending the 10-inch sewer on Alder Street to serve the northeastern portion of the development. Alternative 1 will retain the existing pump stations in the Centralia south sewer area. Therefore, the project construction costs include costs for completing the high-priority improvements to the South Tower, Van Buren, and Jefferson PSs. With the increase in flow resulting from the Centralia Station Development, the south Centralia sewer system will be over capacity during prolonged wet-weather periods. Historically, the Jefferson PS and the surrounding area experience significant amounts of I/I. The increase in hydraulic grade at the force main discharge will increase the pumping head and thus reduce the capacity of the Jefferson PS by approximately 10 percent. Because the Jefferson PS is already overloaded, an I/I reduction project should be completed as part of the Centralia Station project to offset the 10 percent (64-gpm) pump station capacity reduction. The I/I project approach will concentrate on replacing or installing cast-in- place (CIP) liners in the pre-1965 concrete pipe and replacing the associated side sewers. This I/I reduction project could be implemented in the Woodland basin for an I/I reduction project that would replace or rehabilitate approximately 6,370 feet of circa 1924 to 1965 sewer. 5.3.2.2 Alternative 2 (C.I.P. CS-1) Alternative 2 Phase 1 (see Figure 5-3) would provide gravity sewer service to the Centralia Station Development and eliminate four existing pump stations. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-10 BI1212191438SEA Figure 5-2. Centralia Station Development, Alternative 1 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-11 Figure 5-3. Centralia Station Development, Alternative 2 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-12 BI1212191438SEA The four abandoned pump stations will be the Floral, Ace Auto, Van Buren, and Long Road PSs. This alternative will also reduce flows to, and increase the capacity of, the Jefferson PS, which, as noted previously, is currently over capacity during significant wet weather events. A new 18-inch-diameter gravity sewer will be constructed to replace the existing 10-inch-diameter sewer, providing increased sewer capacity to south Centralia. The 18-inch-diameter gravity sewer will run along Long Road to Borthwick Street, receiving the discharge of the Jefferson PS near the intersection of Alder Street and Long Road. This new sewer will eliminate a bottleneck in the gravity sewer system serving south Centralia and increase the capacity of the Jefferson PS (because of a reduction in force main length) and the sewers along South Street, Long Road, Alder Street, and Borthwick Street. This alternative will also reduce infiltration in the existing system by replacing approximately 1,450 feet of aged concrete pipe. In addition to the new 18-inch-diameter gravity sewer, Alternative 2 Phase 2 will collect and convey sewage from the existing southern sewer area and the Centralia Station Development. For the existing sewer area, Fairgrounds PS will continue to pump toward the abandoned Ace Auto PS location, at which point sewage will be conveyed via a new gravity sewer to the South Tower PS. This new gravity sewer will also serve areas currently draining to the Ace Auto and Floral PSs, allowing them to be abandoned. A new gravity sewer between the South Tower PS and Van Buren PS will serve the area currently draining to the Van Buren PS, allowing the Van Buren PS to be abandoned as well. The South Tower PS will be upgraded to a capacity of 580 gpm in order to handle its current service area plus the additional flows from the Van Buren and Floral PS service areas. The upgraded pump station will pump through a new 18-inch-diameter force main (which would cross under the BNSF Railroad tracks) into a new 16-inch gravity sewer on South Street west of Woodland Avenue. This new 16-inch- diameter gravity sewer will discharge to the new 18-inch-diameter gravity sewer on Long Road. Properties on South Street, on the western side of the railroad tracks, will be reconnected to the new 16-inch-diameter gravity sewer. For the properties along South Street and Long Road in the Centralia Station Development, wastewater will flow by gravity to the new 16-inch- and 18-inch-diameter gravity sewers. The remainder of the wastewater from the new development will flow to existing sewers along Alder Street. Costs in 2016 dollars for the two alternatives are summarized in Table 5-5. Table 5-5. Centralia Station Development Cost Estimates Alternative 1 $4,100,000 Alternative 2 Phase 1 (Centralia Station) $3,880,000 Phase 2 (City share) $4,170, 000 Alternative 2 can be implemented in two phases, with Phase 1 providing capacity for the new Centralia Station Development and Phase 2 providing capacity for south Centralia. Phase 1 of Alternative 2 has a lower cost than Alternative 1. Alternative 2 provides the following additional benefits to the City compared to Alternative 1: • Eliminates two pump stations, reducing annual operations and maintenance (O&M) costs for these pump stations • Removes I/I as a result of replacing 1,450 feet of pre-1965 gravity sewer pipe to accommodate new flow from Centralia Station CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-13 • Reduces the flow to the overloaded Jefferson PS by two-thirds, providing additional capacity for new customers in the south service area It is recommended that the City implement Phase 1 of Alternative 2 to serve the new Centralia Station Development, because it is the lowest-cost alternative and provides the most long-term benefits to the City. 5.4 Evaluation of Pump Stations and Force Mains A lift station condition assessment was completed in 2013 with City staff. The assessments include the physical condition of the lift stations, their capacity, and their equipment condition. This assessment served as metric to develop the prioritization of the lift station upgrades. This evaluation also assessed the ability of the existing pump stations and force mains to serve both current demands and projected future flows. The adequacy of the pump station at historical peak wet and dry weather flows was determined by evaluating the pump run times during the wet season and the dry season. Pump run times were determined using telemetry data. The dry season is defined by days in which there was not significant precipitation and when the WWTP flows were below 4 mgd. The wet season is defined by days in which there was significant precipitation or the WWTP flows were at or above 4 mgd. Table 5-6 summarizes the dry and wet weather average daily flows based on information provided by City staff through summer 2014. The difference in run time between wet season and dry season represents an approximation of the I/I present within the collection system. The pump stations with the highest I/I are China Creek (0.88 mgd), Jefferson (0.65 mgd), Borst Park (0.35 mgd), High Street (0.20 mgd), West Mellen (0.16 mgd), and Floral (0.15 mgd), based on the rated station capacity with one pump not in service. Table 5-6. Historical Pump Run Time Records Pump Station Average Dry Weather Flow Average Wet Weather Flow Increase Hours of operation per day mgd Hours of operation per day mgd Hours of operation per day mgd Borst Park 3.5 0.23 8.8 0.58 5.3 0.35 Mt. Vista 1.0 0.01 1.5 0.01 0.5 0.00 Scheuber 1.3 0.04 1.5 0.05 0.2 0.01 Industrial 0.5 0.00 1.2 0.01 0.7 0.00 Jensen 0.5 0.00 1.5 0.01 1.0 0.01 High Street 3.8 0.05 20.0 .24 16.2 0.19 Reynolds 3.3 0.05 4.3 0.06 1.0 0.02 State 0.3 0.00 1.2 0.01 0.9 0.00 Salzer Valley 1.5 0.01 12.9 0.09 11.4 0.08 Floral 1.5 0.03 8.7 0.18 7.2 0.15 Fairgrounds (Gold 1) 1.2 0.01 2.5 0.02 1.3 0.01 Jefferson 2.8 0.11 19.6 0.75 16.8 0.65 Long 0.5 0.00 1.0 0.01 0.5 0.00 West Mellen 5.25 0.09 14.6 0.25 9.35 0.16 Military 1.5 0.01 7.3 0.04 5.8 0.03 Scammon 4 0.05 7.0 0.08 3.0 0.04 Highland Park 1.5 0.01 2.0 0.02 0.5 0.00 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-14 BI1212191438SEA Table 5-6. Historical Pump Run Time Records Pump Station Average Dry Weather Flow Average Wet Weather Flow Increase Hours of operation per day mgd Hours of operation per day mgd Hours of operation per day mgd North Tower 1 0.02 1.4 0.02 0.4 0.01 Van Buren 1.8 0.02 5.9 0.05 4.1 0.04 South Tower 0.3 0.00 1.0 0.00 0.7 0.00 Ace Auto 1.0 0.01 3.4 0.03 2.4 0.02 Marion 1.0 0.01 3.4 0.02 2.4 0.01 Eshom 5.0 0.08 6.9 0.10 1.9 0.03 North Port 0.3 0.01 0.3 0.01 0.0 0.00 China Creek 22.0 1.45 – 5.94 24.0 1.58 – 6.48 2.0 0.13 – 0.54 Total 2.29 – 6.78 4.24 – 9.14 1.95 – 2.36 The pump stations were also evaluated for their ability to transfer flows from the UGA and unsewered areas. This analysis was performed using the peak dry weather sanitary flow and did not include I/I for either the existing flows or the flows from the UGA or unsewered areas, assuming that new sewer lines will not leak. Projected future flows were allocated to each pump station based on the most likely point at which the future flows will discharge to the existing collection system. Table 5-7 summarizes the results of the capacity analysis. The "rated capacity" column is the capacity of the pump station with one pump out of service. The "total flow" column combines the estimated existing flow with the projected flows from unsewered and UGA areas. The pump station is predicted to lack sufficient capacity for future flows, if the total flow is greater than the rated capacity. Table 5-7. Pump Station Capacity for Peak Dry Weather Sanitary Flows Pump Station Rated Capacity (mgd) Existing Flows (mgd) Unsewered Communities (mgd) UGA Areas (mgd) Total Flow (mgd) Borst Park 1.6 0.36 0.02 -US-7 0.38 M. Vista 0.2 0.03 0.03 Eshom 0.4 0.12 0.23 -NS-1 0.23 - NS-2 0.11 - NS-3 0.06 - NS-4 0.53 - NS-7 0.07 - NS-14 1.28 Scheuber 0.7 0.07 0.14 Industrial 0.1 0.01 0.01 Jensen 0.2 0.01 0.01 High Street 0.3 0.02 0.02 Reynolds 0.4 0.05 0.23 -US-6 0.04 - NS-12 0.21 - NS-6 0.53 Marion 0.1 0.02 0.02 State 0.1 0.01 0.13 - NS-9 0.14 Salzer Valley 0.2 0.01 0.01 Floral 0.5 0.04 0.04 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-15 Table 5-7. Pump Station Capacity for Peak Dry Weather Sanitary Flows Pump Station Rated Capacity (mgd) Existing Flows (mgd) Unsewered Communities (mgd) UGA Areas (mgd) Total Flow (mgd) Ace Auto 0.2 0.01 0.01 Fairgrounds 0.2 0.01 0.01 S. Tower 0.1 0.01 0.01 Van Buren 0.2 0.05 0.05 Jefferson 0.9 0.22 0.22 Long 0.2 0.03 0.18 -NS-8 0.21 W. Mellen 0.4 0.17 0.02 -US-1 0.003 -US-2 0.42 -NS-5 0.19 - NS-15 0.663a Military 0.1 0.03 0.003 -US-2 0.19 - NS-15 0.223 Scammon 0.3 0.09 0.02 -US-1 0.42 -NS-5 0.53 Total 7.4 1.37 3.87 a Capacity should be evaluated during wet weather conditions also. Note: Pump station capacities that are exceeded are shown in bold. West Mellen, State, Military, and Scammon pump stations should be evaluated further if development occurs that would discharge to these pump stations. This analysis should be repeated for conditions representing the 5-year storm to provide certainty that this initial assessment is correct. The pump station run times should be reviewed for two periods of at least 1 week each, during wet weather conditions when the Chehalis River flow is approximately 33,000 cfs according to National Oceanic and Atmospheric Administration. Force main capacity was evaluated for each of the pump stations that would experience flow increases due to future flows from unsewered or UGB areas, as indicated in Table 5-7. The velocity through the related force mains was calculated for peak sanitary sewage flows for combined existing and future flows. Acceptable velocities are between 4 and 6 feet per second (fps). The results of this analysis are summarized in Table 5-8. Table 5-8. Force Main Analysis for Peak Dry Weather Sanitary Flows Pump Station Force Main Size (inches) Existing Flow (mgd) Future Flow (mgd) Total Flow (mgd) Velocity (fps) Borst Park 10 0.36 0.02 0.38 1.1 Eshom 6 0.12 1.16 1.28 10.1 Reynolds 6 0.05 0.48 0.53 4.2 Long 6 0.03 0.18 0.21 1.7 W. Mellen 6 0.17 0.493 0.663 5.2 Military 4 0.03 0.193 0.223 4.0 Scammon 4a 0.09 0.44 0.53 9.4 a 4-inch force main discharges to 8-inch at Scheuber Road This analysis indicates that velocities will be excessive through the Eshom and Scammon force mains for peak dry weather sanitary flows. Therefore, it is concluded that these force mains will be inadequate for CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-16 BI1212191438SEA projected future flows if development occurs in these pump station basins. This analysis should be repeated to evaluate the sufficiency of the force mains under wet weather conditions after flow monitoring is performed to quantify the I/I within the existing system. This can be completed as part of C.I.P. M-1 by City staff. The Fairgrounds, High Street, Jensen, Long Road, Military, and State pump stations have been historically susceptible to flooding for a variety of reasons. The State PS is located within a low-lying area. The Jensen PS is susceptible to flooding from Coffee Creek, and the remaining pump stations experience flooding related to high water in either the Skookumchuck or Chehalis Rivers. Historical protocol has been to sandbag these pump stations when they appear to be in danger of flooding. Table 5-9 presents the surveyed elevations of the wet well rim for each of the pump stations. As the water surface levels rise in the Chehalis River, Skookumchuck River, and Coffee Creek, the operators can sandbag the pump stations as determined by the wet well levels, with the pump stations at the lowest elevations being sandbagged first. Table 5-9. Pump Station Wet Well Rim Elevations Pump Station Wet Well Rim Elevation (feet) Eshom 166.31 M. Vista 169.00 Scheuber 169.04 Military 169.09 Scammon 169.58 Borst Park 170.32 Long 170.76 Fairgrounds 171.94 High Street 172.84 Jefferson 174.37 Ace Auto 174.73 Jensen 175.84 S. Tower 176.05 Industrial 176.08 State 176.45 Salzer Valley 177.01 Floral 177.17 Van Buren 177.37 W. Mellen 180.29 Marion 194.64 Reynolds 195.04 The City has been able to keep the pump stations operational during high flow events through tarping, sand bagging and with the installation of gasketed hatch lids to prevent water intrusion. Military, Gold #1, and Long Road pumps stations have been retrofitted with gasketed lids. Fairgrounds, Jefferson and Borst are tarped and sand bagged prior to a significant storm event. As noted in Chapter 3, Gold Street Pump Station #1 will have the electrical panel elevated above the flood level in the next few years. Water intrusion during a storm event is controlled with the use of these preventive measures. The City may consider other modifications to the existing pump stations to coincide with a future capital improvement project for a pump station as applicable. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5‐17 5.5 Pump Station Assessment and Prioritization A workshop was held with City staff to review the current condition of each of the existing pump stations and the City’s operational efforts. All pump stations in the system were considered for upgrades and were identified as being one of the following: high priority improvements, moderate priority with improvements that would take place in the near term, or low priority with improvements that would take place beyond 2020. The key points of discussion during the workshop were as follows: Physical condition of each pump station Pump station capacity Pump station equipment condition (including instrumentation and control, and electrical) Improvement priority for capital improvement project After developing the list of potential and desired improvements, each pump station was giving a priority ranking based on how urgent the City deemed the improvement. The ranking criteria were as follows: 1. High priority improvements (required action in the years 2016 to 2017) 2. Near‐term improvements (requiring action in the years 2017 to 2019) 3. Future improvements (requiring further evaluation and action after the year 2020) Table 5‐10 shows the priority given to each pump station. High‐priority improvements are further discussed in Section 5.7.4. Table 5‐10. Pump Station Improvement Priority No. Pump Station Telemetry (yes/no) Redundancy Gravity Bypass (yes/no) Priority a 1 Borst Park yes +1 pump on standby N 2 2 Mt. Vista yes +1 pump on standby N 3 3 China Creek yes +1 pump on standby N 1 4 Eshom yes +1 pump on standby N 2 5 Galvin / Scheuber yes +1 pump on standby N 2 6 Industrial Drive yes +1 pump on standby N 1 7 Jensen yes +1 pump on standby N 3 8 High Street yes +1 pump on standby N 3 9 Reynolds yes +1 pump on standby N 3 10 Marion yes +1 pump on standby N 3 11 State yes +1 pump on standby N 3 12 Salzer yes +1 pump on standby N 3 13 Floral yes +1 pump on standby N 3 14 Ace Auto (Gold #2) yes +1 pump on standby N 3 15 Fairgrounds (Gold #1) yes +1 pump on standby N 3 16 South Tower yes +1 pump on standby N 3 17 Van Buren yes +1 pump on standby N 2 18 Jefferson yes +1 pump on standby N 2 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5‐18 BI1212191438SEA Table 5‐10. Pump Station Improvement Priority No. Pump Station Telemetry (yes/no) Redundancy Gravity Bypass (yes/no) Priority a 19 Long Road yes +1 pump on standby N 3 20 Mellen yes +1 pump on standby N 3 21 Military yes +1 pump on standby N 3 22 Scammon Creek yes +1 pump on standby N 3 23 Highland Park yes +1 pump on standby N 2 24 North Tower yes +1 pump on standby N 3 25 North Port yes +1 pump on standby N 3 a Priority from 1 to 3, with “1” being high priority and “3” low priority. 5.6 Infiltration and Inflow Alternatives Similar to other cities in Washington State, infiltration and inflow is a key concern. The City has evaluated a number of alternatives to determine the best alternative to resolve I/I. The following sections describe these efforts and outcomes. 5.6.1 I/I Reduction Projects to Comply with Ecology Administration Order Ecology Agreed Order No. DE 02WQSR‐3551 was originally requested by the City for the NPDES permit for the new WWTP to obtain a waiver of 85 percent removal for BOD and TSS. Historical data from the old WWTP showed that influent BOD and TSS would be less than 100 mg/L during high flows, and 85 percent removal would require effluent less than 15 mg/L. This potentially could require effluent filtration. As a result, the City requested a waiver from 85 percent removal to 75 percent removal for BOD and 70 percent removal for TSS that was incorporated into NPDES permit No. WA0020982 for when the Chehalis River flow exceeds 1,000 cfs. Ecology required that the City agree to Agreed Order No. DE 02WQSR‐3551, which required the City to complete I/I projects on a defined schedule to obtain the waiver from 85 percent removal for BOD and TSS. The City has completed all the I/I removal projects in the Agreed Order through the year 2015. Beginning in the year 2017, the Agreed Order required the City to replace 7,000 feet of old ungasketed gravity sewer pipe to reduce I/I until 85 percent removal could be achieved. The cost of replacing this pipe was estimated to be greater than the City could afford, and the City requested that the actual percent removals for the WWTP be evaluated to see if the 85 percent removal waiver was still needed. In 2006 and 2007, there were a few instances where the BOD and TSS percent removal was less than 85 percent. Since this time, the City has taken a number of steps that have improved percent removal of BOD and TSS. The City changed operation of the China Creek PS to limit maximum flows to the WWTP based on the water level in an indicator manhole to prevent sewer overflows upstream. Operational improvements were also implemented at the WWTP to treat high flows more efficiently. Finally, the City completed all the I/I removal projects scheduled in the Agreed Order through the year 2015, and these have likely reduced the maximum amount of I/I that reaches the WWTP. There have been several major flood events in this time period, including the flood of record in December 2007, and the WWTP has generally exceeded 85 percent removal with the exception of December 2015. Meeting permit limits and achieving a minimum of 85 percent removal for BOD and TSS is a priority for the City and the WWTP personnel strive to operate the WWTP effectively. Additionally, the C.I.P. includes sliplining and other I/I investigative, planning and implementation projects to continue resolving the high I/I the collection CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-19 system realizes. Appendix D includes inflow and infiltration projects that the City has undertaken to reduce I/I within the collection system. The City requested that Ecology terminate the Agreed Order and modify the NPDES permit to eliminate the waiver of 85 percent removal. This provides the City with flexibility in implementing I/I removal projects to maintain conveyance and treatment capacity as required. This request was approved as part of the 2016 NPDES permit renewal. 5.6.2 Infiltration and Inflow Pilot Projects Pilot I/I reduction projects were evaluated for potential application in Centralia. This evaluation included the following: • Selecting pilot project locations • Identifying technology candidates • Determining pilot project size • Developing evaluation criteria for the pilot projects • Developing costs for the pilot projects The City had previously completed several I/I reduction projects as part of its plan to comply with the Ecology requirement for I/I removal. A portion of the collection system tributary to the Jefferson interceptor was identified as the best candidate for conducting pilot I/I reduction projects with different rehabilitation technologies. This pilot area was selected for the following two reasons: 1. It provided the most homogeneous area in terms of pipe material and size, as well as home construction era and type. This homogeneity will improve the comparison of different rehabilitation technologies performed under similar circumstances. 2. The area is within the project limits for the I/I reduction projects previously identified. The City has included this in their capital improvement plan in order to determine the best rehabilitation technique (see Section 5.7.5). In addition, the existing per capita flow rates for the City are above the criteria set by the EPA for inflow indicating that sources of inflow should investigated as part of an inflow and infiltration study. The City should conduct a detailed and thorough I/I study to confirm the results of the I/I evaluation presented in Chapter 3 and to locate the affected collection system areas to determine if there are any cost-effective sewer rehabilitation measures to remove any excessive inflow. 5.6.3 Feasibility Evaluation of the Cost of Increasing the Hydraulic Capacity of the WWTP to Address I/I A preliminary evaluation was completed of the cost of increasing the hydraulic capacity of the WWTP in order to handle I/I. The intent of the evaluation was to compare these costs with collection system I/I reduction costs to determine whether I/I reduction in the collection system is cost-effective compared to upgrading the WWTP to manage extraneous water that occurs during wet weather events. This evaluation was limited to a hydraulic evaluation and did not include treatment capacity evaluation. The current WWTP hydraulic capacity is 10 mgd based on the firm, peak capacity of the China Creek PS, force main interceptors from the China Creek PS to the WWTP, effluent pump station, and outfall. The costs of expanding these facilities to 15 mgd (a 5-mgd increment) and 20 mgd (doubling the capacity) were both evaluated. The upgraded facilities were planned with an ultimate possible expansion to 30 mgd. Class 5 cost estimates were developed for expanding the pump station to 20 mgd, adding a third force main, expanding the WWTP unit processes to 15 mgd and 20 mgd, and increasing the capacity of the effluent pumps and outfall to 20 mgd (Table 5-11). These costs were originally developed in 2013 dollars and were escalated to 2016 dollars using the 20-city average CCIs published by ENR. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-20 BI1212191438SEA The cost of expanding the WWTP capacity is $27 million for a 5-mgd increase in capacity and $34 million for a 10-mgd increase in capacity, equating to $5.40 per gallon for 5 mgd and $3.40 per gallon for 10 mgd. Unlike collection system I/I removal costs, which can be spent in small increments over a period of time, expansion of the WWTP capacity requires large improvements (and their larger costs) that provide steps of capacity. As described in Section 6.1, the City is continuing its I/I reduction efforts to better quantify I/I flow reduction for comparison to the costs of additional wastewater treatment plant hydraulic capacity. At this time, the City does not plan to expand the wastewater treatment plant hydraulic capacity in order to manage I/I as a result of extreme storm events. Table 5-11. Estimated Expansion Cost to Accommodate Hydraulic Capacity Expansion Instead of I/I Reduction Item Low Range (-30%) Base Cost High Range (+50%) Additional Force Main $10,230,000 $14,600,000 $21,630,000 Upgraded Pump Station (15 mgd) $910,000 $1,300,000 $1,950,000 Upgraded Pump Station (20 mgd) $1,620,000 $2,300,000 $3,470,000 Upgraded WWTP (15 mgd)a $7,940,000 $11,300,000 $16,970,000 Upgraded WWTP (20 mgd)b $11,660,000 $16,680,000 $25,010,000 Total for expansion to 15 mgd (5-mgd increase) $19,080,000 $27,200,000 $40,550,000 Total for expansion to 20 mgd (10-mgd increase) $23,510,000 $33,580,000 $50,110,000 a Includes increasing WWTP unit process hydraulic capacity to 15 mgd and upgrading WWTP effluent pumps, pipeline, and outfall to 20-mgd capacity b Includes increasing WWTP unit process hydraulic capacity to 10 mgd and upgrading WWTP effluent pumps, pipeline, and outfall to 20-mgd capacity 5.7 Recommended Improvements This section presents the recommended improvements to the existing collection system. These improvements will provide service to future growth areas and unsewered communities, address capacity deficiencies related to providing service, and remedy existing system deficiencies. These improvements were developed based on the results of the analysis described previously. In all cases, the improvements were developed with a goal of minimizing cost while maximizing performance of the existing system. The timing of the improvements to new service areas will be driven by development in those areas, cost, and the City's desire to provide service. The historical approach to sewer service development has been to allow individual developers to install the service required solely for the new development. This has resulted in numerous small pump stations and shallow collection systems that cannot be extended to additional service areas. This practice should be modified to minimize the number of pump stations and to provide gravity sewer service by regulating the depth of the pump station wet wells and collection sewers to allow conversion of the collection system proposed for the new development to gravity sewer in the future. The collection sewers should have a slope no greater than 0.004 foot per foot, and the main collector sewer should be located in accordance with the conceptual design discussed and with an invert such that it could be extended to connect with the collection system. Pump station wet wells should be shallow enough to allow them to be drained by gravity to the existing collection system, wherever possible. Pipeline routing for new service areas was determined primarily by existing roads. Where no roads existed, the pipelines were routed between land ownership boundaries or by location of existing housing if land ownership boundaries were unknown. Actual routing may differ somewhat based on the City’s ability to acquire easements, projects in the area that may afford opportunities for coordination of CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-21 utility corridors, and other factors. In all cases, the 8-inch pipelines were assumed to have a slope of 0.004 foot per foot, and 10-inch lines were assumed to have a slope of 0.000285 foot per foot, which are the minimum slopes for gravity sewers allowed by Ecology. It should be noted the costs of repairing existing roadways adds significant additional cost for patching, overlay, and flaggers and traffic control. Pipeline excavation costs are nearly half the estimated cost, if the pipeline work is done at the same time road work is done. Coordination to construct pipeline projects concurrently with road projects is recommended to minimize the cost of constructing new sewer pipelines. Construction of sewer pipelines outside of pavement is less expensive, if right-of-way and easements are available. Development of sewer plans for new areas added to the UGA (Ford's Prairie, Waunch Prairie/Davis Hill, Cook's Hill, Widgeon Hill, and former City Golf Course) for the City were developed using the following assumptions. Areas, land use designations, and development densities are from the adopted Centralia Comprehensive Plan. The residential densities used for estimating maximum populations are summarized as follows: • Very low (VLDR) – 2 DU/acre • Low (LDR) – 4 DU/acre • Medium (MDR) – 8 DU/acre • Medium to High (M-HDR) – 15 DU/acre • High (HDR) – 16 DU/acre The following assumptions were made for the collection system improvements: • Residential population was estimated assuming 2.4 persons per DU. • Average residential wastewater flows are estimated assuming 76 gallons per capita per day. • Peak residential wastewater flows are estimated by multiplying the average flow times at a peaking factor of 2.92 for new sewers. • Commercial average flow was estimated using 2,000 gallons per acre per day. • Industrial average flow was estimated using 1,000 gallons per acre per day. • The industries will produce domestic wastewater only and will not produce any process water. • Peak commercial and industrial flows were estimated by multiplying average flow by a peaking factor of 2.83. • I/I allowance has been added in addition to wastewater flow and is assumed to be 1,000 gallons per acre per day. • Gravity sewers will be located in existing public right-of-way in roadways. • Gravity pipeline sizing was based on required flow capacity and minimum slopes in Table Cl-1 in Ecology’s Criteria for Sewage Works Design (Ecology, 2019). The City follows the sewer standards outlined by Ecology. • Gravity sewers were assumed to have a minimum depth of 5 feet and maximum depth of 15 feet below grade. • The maximum length of service laterals would be 150 feet. • Grinder pumps were assumed to be used in areas that could not be served with gravity sewers because of low elevation relative to the nearest gravity sewer, in low density development areas and areas where extreme elevation changes made gravity sewers impractical. The alternatives CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-22 BI1212191438SEA analysis for providing sewer service to low density residential areas that cannot be served by gravity is presented later in this section. Sewer plans were developed for each geographic area added to the future service area and present the approximate location of gravity sewers, pump stations, and force mains. Individual side sewers, grinder pumps, and small diameter pressure sewers serving grinder pumps are not shown. Sizes and burial depths are estimated for pipe segments for the purpose of showing concept feasibility and for estimating the cost of the pipelines. Using gravity sewers wherever possible is preferred because of the low O&M cost and reliability of gravity sewers. New pump stations should be minimized, and efforts should be made to eliminate existing pump stations where possible because of the higher O&M cost of pump stations. Flows from subareas of each of the new development areas were estimated as described previously. Service to each area was determined by reviewing the topography and application of design criteria for gravity sewers. Topography from the June 2006 and September 2006 orthophotos and topographic maps of the City was used to evaluate potential gravity sewer alternatives. Costs were estimated for gravity sewers, pump stations, force mains, and collector pressure sewers serving significant areas on grinder pumps. The following costs are not included: • Individual service laterals • Grinder pumps • Small diameter pressure sewer serving a small number of grinder pumps • Electrical service • Emergency generator • Obtaining rights-of-way or easements The cost estimates are Class 5 estimates that have an expected accuracy of plus 100 to minus 50 percent of the actual cost when adjusted for the actual date of construction. The accuracy is low, because the level of project definition is low. It is recommended that design and site-specific estimates be developed for each potential sewer project prior to developing a budget for construction. The costs are expressed in July 2016 dollars. The cost opinion shown has been prepared for guidance in project evaluation from the information available at the time of preparation. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope, final project schedule, and other variable factors. As a result, the final project costs will vary from the cost presented herein. Because of these factors, funding needs must be carefully reviewed prior to making specific financial decisions or establishing final budgets. The costs include 30 percent for contingency; 25 percent for engineering, legal, and administration; and 8 percent sales tax. It is assumed that the construction will encounter minimal groundwater and utility conflicts. Pipeline costs assume imported backfill, asphalt patching and full width overlay, and flaggers and traffic control when the pipeline is located within a roadway. 5.7.1 Existing Collection System Deficiencies The recommended improvement projects described below were developed to address the existing collection deficiencies and to upgrade those portions of the existing collection system that will be insufficient to accept the projected future flows. Costs are estimated for all the improvement projects and are presented in the Capital Improvement Program in Chapter 7 of this General Sewer and Facilities Plan. For existing pipeline projects, estimated costs are based on pipeline replacements. Alternative construction techniques, such as slip-lining and pipe bursting, can also be explored to determine the potential cost savings and decrease in site disturbances. Projects are coded using "ES" to designate existing system features. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-23 ES-1, Pipeline Replacement Program. This will be an ongoing maintenance program over the next 20 years to replace the oldest existing clay and concrete pipes that are approaching or have exceeded their design life. These older pipes are expected to crack at the end of their design life. Additionally, many of the older pipes were not originally installed with gaskets at the pipe joints and tend to be deeper pipes serving as main trunk sewers. These factors combine to make these older pipes more susceptible to groundwater-related I/I. This program would target the oldest pipes for replacement and may have the additional benefit of I/I reduction. The cost estimate for this project is $870,000/year in 2016 dollars. ES-4, First Street Between G and F Streets. This project will replace 398 lf of cracked existing 8-inch sewer line with a new 8-inch line. The cost for this sewer is estimated to be $160,000 in 2016 dollars. 5.7.2 New Development Area Improvements 5.7.2.1 Ford’s Prairie Area Figure 5-4 presents the proposed new pump station and sewers to provide sewer service to the Ford's Prairie area. Figure 5-5 shows the remaining proposed projects for new sewers and unsewered areas identified in the 2000 General Sewer Plan. The area can be served almost entirely by conventional gravity sewers. A new gravity interceptor sewer is proposed along Harrison Avenue and Reynolds Avenue to provide sewer service to most of this area and to Waunch Prairie /Davis Hill. Areas adjacent to Harrison and Reynolds Avenues will be served by gravity trunk sewers draining to the interceptor along these streets. The existing Scheuber PS will pump into the new gravity interceptor and remove this flow from the Borst Park PS. The Industrial PS will pump into the gravity interceptor sewer serving Waunch Prairie /Davis Hill. The gravity interceptor sewer will flow to the recently completed North Port PS at the intersection of Kuper Road and Harrison Avenue. The North Port PS will pump collected wastewater to the WWTP through twin force mains under Goodrich Road. Implementation of this plan requires construction of the new gravity interceptor sewer beginning at the North Port PS and extending this interceptor to the location of desired sewer service. It is recommended that this interceptor be constructed before or concurrently with improvements to Harrison Avenue. The phasing of construction will depend on the availability of funding and timing of development in the Ford's Prairie sewer basin. For the purposes of describing the different elements of this sewer plan, the sewers are grouped into 10 separate projects. Figure 5-4 lists the individual segments, and Table 5-12 provides a cost breakdown by individual segments. The main constraint is that the most downstream sewer segments need to be constructed first to permit gravity flow to the North Port PS. Table 5-12. Ford’s Prairie Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost F-1 Ford's Prairie Interceptor F-1.1 430 36 $526,000 F-1.2 960 36 $1,170,000 F-1.3 620 36 $760,000 F-1.4 2,300 36 $2,800,000 F-1.5 1,040 36 $1,270,000 F-1.6 1,400 36 $1,710,000 F-1.7 220 36 $270,000 F-1.8 1,330 36 $1,630,000 F-1.9 160 36 $200,000 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-24 BI1212191438SEA Table 5-12. Ford’s Prairie Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost F-1.10 840 12 $560,000 F-1.11 60 12 $40,000 F-1.12 220 12 $150,000 F-1.13 690 12 $350,000 F-1.14 700 12 $360.000 F-1.15 620 12 $370,000 Total $11,810,000 F-2 Area North of and Adjacent to Kuper Road F-2.1 2,400 10 $1,150,000 F-2.2 1,460 10 $630,000 F-2.3 460 8 $290,000 F-2.4 380 8 $240,000 F-2.5 1,020 10 $487,000 F-2.6 400 8 $150,000 Total $2,950,000 F-3 Private Drives Area F-3.1 1,200 8 $640,000 F-3.2 1,260 8 $670,000 Total $1,310,000 F-4 Trailer Park Area F-4.1 60 8 $41,000 F-4.2 560 8 $360,000 F-4.3 240 8 $150,000 F-4.4 100 8 $60,000 F-4.5 580 8 $310,000 F-4.6 120 8 $60,000 F-4.7 645 8 $290,000 Total $1,270,000 F-5 Southeast Area F-5.1 2,660 10 $1,280,000 F-5.2 760 12 $580,000 F-5.3 690 12 $460,000 F-5.4 1,470 10 $700,000 F-5.5 540 8 $240,000 F-5.6 380 8 $230,000 F-5.7 490 8 $310,000 F-5.8 380 8 $230,000 F-5.9 1,210 12 $800,000 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-25 Table 5-12. Ford’s Prairie Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost F-5.10 1,640 10 $790,000 F-5.11 400 8 $180,000 F-5.12 390 8 $180,000 F-5.13 650 12 $460,000 F-5.14 3,090 10 $1,480,000 Total $7,920,000 F-6 Industrial Area F-6.1 840 10 $470,000 F-6.2 1,180 10 $570,000 Total $1,040,000 F-7 Reynolds Avenue Area F-7.1 200 15 $170,000 F-7.2 1,680 15 $800,000 F-7.3 880 8 $560,000 F-7.4 1,640 15 $1,010,000 Total $2,540,000 F-9 Southwest Area F-9.1 1,710 15 $440,000 F-9.2 1,050 15 $750,000 F-9.3 660 15 $410,000 F-9.4 300 10 $140,000 F-9.5 240 8 $110,000 F-9.6 240 10 $120,000 F-9.7 240 8 $90,000 F-9.8 240 10 $120,000 F-9.9 250 8 $100,000 F-9.10 50 8 $20,000 F-9.11 190 8 $120,000 F-9.12 400 8 $250,000 F-9.13 460 8 $290,000 F-9.14 360 8 $230,000 F-9.15 660 8 $350,000 F-9.16 340 8 $150,000 F-9.17 640 8 $340,000 Total $4,030,000 F-10 Gallagher Road Area F-10.1 550 6 $180,000 F-10.2 180 8 $110,000 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-26 BI1212191438SEA Table 5-12. Ford’s Prairie Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost F-10.3 1,680 15 $1,190,000 F-10.4 80 8 $40,000 F-10.5 1,000 10 $430,000 ‘ Total $1,950,000 Land uses used for estimating wastewater flows are summarized in Chapter 2. Urban Growth Area (UGA) Boundary Sewer Basin Boundary Existing Gravity Sewer Existing Force Main Pump Station New Gravity Sewer New Force Main Line Designation NewExist Legend N SCALE IN FEET 750 15000 FIGURE 5-4 Ford’s Prairie Basin Urban Growth Area City of Centralia General Sewer/Facility Plan WT0621161107SEA Fig5-5_FordsPrairieUGA_v7 CENTRALIA MAPPING1"=200' SCALE AERIALS25 FT CONTOURS ABOVE ELEV 2005 FT CONTOURS BELOW ELEV 200 Chehalis River F-1.15F-1.15F-1.15 F-2.6 F-1.14F-1.13F-2.2 F-1.12F-2.4 F-1.11F-1.10 F-1.1 F-4.2 F-4.3F-4.3F-4.3F-4.1F-4.5 F-4.7F-1.2F-3.2 F-1.3 F-3.1 F-5.1F-5.1F-5.1F-5.5 F-5.4F-5.3F-5.2 F-5.6F-5.7F-5.8 F-5.11 F- 1 . 8 F- 1 . 8 F- 1 . 8 Scheuber PS F-7.1 F-7.2 F-7.4F-7.3F - 1. 7 F-5.14F- 1 . 4F- 1 . 4F- 1 . 4 F-1 . 5 F-1 . 5 F-1 . 5 F-9.1F-9.3 F-9.2 F-10.2 F-10.3F-9.5 F-9.7 F-10.4 F-9.9 F-1.1F-10.5F-9.4 F-9.6 F-9.8 F-9.10 F-9.12 F- 1 . 6 F-1. 6 F- 1 . 6 F-9.14 F-6.1 F-9.17 F-6.2F-9.16 F-9.15F-9.15F-9.15 F-9.13F-9.13F-9.13 F-9.11F-9.11F-9.11 F-10.1 F-5.9 F-5.13 F-5.10F-5.12F-4.6 F-4.4 F-2.1 F-2.3 F-25 F-1 . 9 F-1.9 F-1 . 9 UNK F:\CENTRALIA_SEWERWASTEWATER\GIS\MAPFILES\CENTRALIA_SEWER_11X17_LANDSCAPE_NEWSEWER.MXD LH013853 7/29/2016 1:46:51 PM Centralia LEWIS COUNTY §¨¦5 §¨¦5 Graf RdSeminary Hill RdS Gold StHar r i s o n A v e Galvin Rd Cooks Hill Rd Halliday RdAi rpo rt Rd Little Ha n a f o r d R d Salze r V a l l e y R dJ StH StHam Hill RdF StS Scheuber RdB StBorst Ave N Gold StW Main S t Yew StIves R d S Silver StRussell Rd Fair St Blancha r d R d Bl a i r R d Central BlvdEshom RdW Reynolds AveTaylor StL StGrimes RdJohnson RdMarion St McAtee RdMilitary RdBlack Bear Ln W Plum S t N Tower AveRowswell Rd Aivord RdTeitzel Rd Tri Mountain LnBryden AveState St Gleason RdHam Rd Battler i d g e R d Duffy StAlpenwood RdCs Lewis Dr £¤12 £¤12 UV507 C h e h a lis River S k o o k u m ch u ck River Hanaford CreekChehalis RiverHayesLake PlummerLake HorseshoeLake FortBorstLake Data Sources:Esri, NOAA, WSDOT, King County, Lewis County, US Census Bureau, USGS FIGURE 5-5Proposed New Sewer (NS) and Unsewered (US) ProjectsCity of CentraliaGeneral Sewer/Facility Plan Project Location Tacoma Seattle Spokane Vancouver Bellingham Port Angeles ¯0 0.25 0.50.125 Miles US-7 Legend Existing Sewer Force Main New Sewer Force Main Rail Waterbody City Urban Growth Area (UGA) County Pump Station Pump Station NS-7 NS-5 NS-15 US-2 US-3 NS-9 NS-10 US-4 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-30 BI1212191438SEA F-1, Ford's Prairie Interceptor The gravity interceptor conveys flows from all areas in Ford's Prairie and Waunch Prairie/Davis Hill to the North Port PS located on Kuper Road, a short distance from Harrison Avenue. A portion of the 36-inch-diameter interceptor adjacent to the pump station has been constructed to avoid a conflict with the pump station during construction. It would extend from Reynolds Avenue north to approximately the Thurston County line. Residences and businesses located adjacent to Harrison Avenue will discharge flows directly into this interceptor. The Ford's Prairie interceptor includes the following sewers: • 8,460 lf of 36-inch sewer • 3,130 lf of 12-inch sewer The estimated cost of the entire Ford's Prairie interceptor in July 2016 dollars is $11,810,000. It can be constructed in phases, if desired, beginning at the North Port PS. F-2, Area North of and Adjacent to Kuper Road This area is designated as commercial and industrial in the City Comprehensive Plan. The sewers to serve this area include the following: • 1,240 lf of 8-inch sewer • 4,880 lf of 10-inch sewer The estimated cost of these sewers in July 2016 dollars is $2,950,000. F-3, Private Drives Area The private drives area is located just south of Goodrich Road and extends west from Harrison Avenue. The sewers to serve this area include the following: • 2,460 lf of 8-inch sewer The estimated cost of these sewers in July 2016 dollars is $1,310,000. F-4, Trailer Park Area The trailer park area is located south of the Port PS. There is an existing 8-inch gravity sewer line that travels south from the pump station, beneath Kuper Road. This sewer line can convey flows directly from this area into the pump station wet well. The sewers to serve this area include the following: • 2,305 lf of 8-inch sewer The estimated cost of these sewers in July 2016 dollars is $1,270,000. F-5, Southeast Area The southeast area includes trunk sewers located in existing roads. These roads are Sandra Avenue East, Foron, Bennett, Taylor, Van Wormer, and existing adjoining roads. The sewers to serve this area include the following: • 2,580 lf of 8-inch sewer • 8,860 lf of 10-inch sewer • 3,310 lf of 12-inch sewer The estimated cost these sewers in July 2016 dollars is $7,920,000. These sewers can be constructed in phases as needed to serve development as it occurs and are grouped together only for discussion purposes. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-31 F-6, Industrial Area A portion of this area is currently being served by the Industrial PS. The sewers to serve this area include the following: • 2,520 lf of 8-inch sewer The estimated cost of these sewers in July 2016 dollars is $1,040,000. F-7, Reynolds Avenue Area The Waunch Prairie gravity interceptor is a 15-inch diameter sewer that conveys flows from Waunch Prairie/ Davis Hill and Industrial PSs to the Ford's Prairie interceptor. It continues in the Waunch Prairie/Davis Hill sewer basin described later. The portion described in the Ford's Prairie sewer basin extends from the I-5 overpass west to Harrison Avenue. A gravity sewer to serve an area north of the Industrial PS is included in this area. The sewers to serve this area include the following: • 880 lf of 8-inch sewer • 3,520 lf of 15-inch sewer The estimated cost of these sewers in July 2016 dollars is $2,540,000. F-9, Southwest Area The southwest area includes the drainage area served by the gravity sewers discharging into the Ford's Prairie interceptor at the intersection with Sandra Avenue. The sewers serving this area include the following: • 3,830 lf of 8-inch sewer • 780 lf of 10-inch sewer • 3,420 lf of 15-inch sewer The estimated cost these sewers in July 2016 dollars is $4,030,000. These sewers can be constructed in phases as needed to serve development as it occurs and are grouped together only for discussion purposes. F-10, Gallagher Road Area This area serves areas adjacent to Gallagher Road and includes a gravity sewer that flows north to the proposed Ives Road PS. A new 780-gpm pump station is proposed near the Gallagher and Ives intersection, because the ground surface elevations in the area are low. A portion of Cook's Hill wastewater (540 gpm) will be pumped to this pump station. It will pump 550 feet to a gravity sewer into a gravity sewer to the east on Ives Road. The gravity sewers, pump station, and force main to serve this area include the following: • Pump station with two 15-hp pumps • 550 lf of 6-inch force main • 260 lf of 8-inch sewer • 1,000 lf of 10-inch sewer • 1,680 lf of 15-inch sewer The estimated cost of force main and gravity sewers in July 2016 dollars is $1,950,000. The estimated cost of the Ives Road PS in July 2016 dollars is $350,000. A few low elevation areas shown on Figure 5-4 are most likely best served using grinder pumps. Costs for grinder pumps and associated small-diameter force mains are not included in the CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-32 BI1212191438SEA aforementioned costs, because these costs would likely be paid for by property developers. Costs for side sewers to individual services are also not included in the aforementioned costs. NS-7, Fords Prairie Residential This area is designated as Residential in the City Comprehensive Plan. The existing sewer in Fords Prairie was originally designed to be expanded to serve the NS-7 project area. Stubouts exist in the existing system at the correct inverts to extend service (Figure 5-5). The Eshom PS will have to be upgraded to accept the additional flows, and the force main will be rerouted to discharge to the Sandra PS. The NS-7 conceptual sewer includes the following: • 11,900 lf of 8-inch sewer • Upgrades to Eshom PS and force main The estimated cost of the force main and sewers in July 2016 dollars is $8,200,000. US-7, Fords Prairie This sewer would provide service to the unsewered residences located east of Fords Prairie within the City limits. This area is also designated Residential. Service can be provided by stubbing out from the existing pipeline at a manhole located at the intersection of Harrison and Fords Prairie Roads. These flows will discharge into Basin 9. The US-7 conceptual sewer includes the following: • 1,750 lf of 8-inch sewer The estimated cost of this sewer in July 2016 dollars is $1,090,000. 5.7.2.2 Cook's Hill Area Figure 5-6 presents the proposed sewers and pump stations to provide sewer service to the Cook's Hill area. The extreme elevation differences and low development density will lead to the use of grinder pumps for most of the services in this area zoned very low density residential. Gravity sewers are used where possible to collect wastewater and convey it off Cook's Hill. Pump Station No. 1 is needed to convey wastewater over a rise in the southern area of Cook's Hill. Wastewater then flows into an existing gravity sewer, where it will flow to the West Mellen PS. Wastewater from the northwestern portion of Cook's Hill will be collected by another gravity sewer to be conveyed to Pump Station No. 2 where it will be pumped to Pump Station No. 3. Wastewater from the northeastern portion of Cook's Hill will be collected by a gravity sewer and conveyed to Pump Station No. 3. Pump Station No. 3 will pump wastewater collected from the northern portion of Cook's Hill to a gravity sewer in southwestern Ford's Prairie. The gravity sewer will flow to a new pump station where it will be pumped to the Ford's Prairie Interceptor. Construction of sewers on Cook's Hill must begin with the pump stations and sewers at the lower portion of the hill. Significant gravity sewers are needed for collection of wastewater pumped from individual grinder pumps at each residence. Northern Cook's Hill requires construction of gravity sewers, a new pump station, and the Ford's Prairie Interceptor to provide sewer service. The costs of the grinder pumps and branch small diameter pressure sewers or side sewers where gravity service is possible are not included in the costs shown in Table 5-13. All costs presented in this section are in July 2016 dollars. The pipeline lengths, pipe diameters, pump station sizes, and total costs for the facilities required to provide sewer service to Cook's Hill are summarized in Table 5-13. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-33 Table 5-13. Cook’s Hill Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost T01a 3,600 8 $1,560,000 T01b 1,150 8 $500,000 T02 7,300 8 $3,170,000 T03 5,000 8 $2,170,000 FM01 1,650 2.5 $620,000 FM02 1,000 6 $370,000 FM03 700 6 $260,000 FM04 2,800 3 $1,040,000 FM05 1,300 4 $480,000 FM06 1,850 3 $690,000 FM07 1,600 3 $600,000 FM08 3,000 6 $1,120,000 FM09 5,200 6 $1,940,000 Total (C.I.P. CH-1) $14,520,000 Pump Stations No. 1 200 gpm $330,000 No. 2 275 gpm $330,000 No. 3 380 gpm $370,000 Pump Station Total (C.I.P. CH-2) $1,030,000 NS-5, Cooks Hill Residential Figure 5-6 illustrates the sewer improvements that would be required in order to serve the potential saturation development on Cooks Hill. A combination of gravity sewers and pump station upgrades will be required to serve all residences within the 20-year UGA. Scammon PS and its force main will need to be upgraded. In order to avoid upgrades to the Mellen Street PS, the Scammon PS force main would discharge directly to the WWTP pump station via a new line suspended under the Mellen Street bridge. These flows will discharge to Basin 14. The NS-5 conceptual sewer includes the following: • 5,200 lf of 8-inch sewer • 3,600 lf of 10-inch sewer • 4,400 lf of 6-inch force main • Upgrades to Scammon PS The estimated cost for these improvements in July 2016 dollars is $7,450,000. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-34 BI1212191438SEA NS-15, Graf Road Residential This area is designated Residential in the City Comprehensive Plan, and can be served with small collector sewers and a pump station, which would discharge to Basin 16. Military PS will need to be upgraded to be able to transfer the flows. The NS-15 conceptual sewer includes the following: • 3,800 lf of 8-inch sewer • 3,200 lf of 4-inch force main • New pump station • Upgrades to Military PS The estimated cost for these improvements in July 2016 dollars is $4,660,000. US-2, South Cooks Hill Residential The five existing unsewered residences west of the junction of South Scheuber Road and J. Graf Road can be served by extending the existing sewer, which is routed down Shamrock Road. These flows will discharge to Basin 16. The US-2 conceptual sewer includes the following: • 100 lf of 8-inch sewer The estimated cost for this sewer in July 2016 dollars is $80,000. NSCALE IN FEET 600 12000 FIGURE 5-6 Cook’s Hill Basin Urban Growth Area City of Centralia General Sewer/Facility Plan WT0621161107SEA Fig5-7_CooksHillUGA_v4 CENTRALIA MAPPING1"=200' SCALE AERIALS25 FT CONTOURS ABOVE ELEV 2005 FT CONTOURS BELOW ELEV 200 Chehali s Ri v er Urban Growth Area (UGA) Boundary Sewer Basin Boundary Existing Gravity Sewer Existing Force Main Pump Station New Gravity Sewer New Force Main Elevation Line Designation Legend CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-36 BI1212191438SEA NS-9, Kresky Residential I Commercial One-third of this area is designated Commercial; the remaining two-thirds are designated Residential. A series of sewers will collect flows from the area and transfer them to State PS. It is assumed that the wet well will need to be modified, because the required pipe inverts are lower than the bottom of the existing wet well. These flows will discharge to Basin 24. The NS-9 conceptual sewer includes the following: • 2,800 lf of 8-inch sewer • Modifications to the State PS The estimated cost for these improvements in July 2016 dollars is $2,120,000. US-3, East of Plummer Lake A conceptual sewer for project US-3 was developed to serve the 19 unsewered residences located east of Plummer Lake along West Main Street. The 8-inch trunk sewer can be tapped into a manhole located west of the comer of West Main and Tilley Avenue. These flows will discharge to Basin 4. The US-3 conceptual sewer includes the following: • 1,100 lf of 8-inch sewer The estimated cost for this sewer in July 2016 dollars is $670,000. 5.7.2.3 Waunch Prairie/Davis Hill Area Figure 5-7 presents the gravity sewers and force mains needed to provide sewer service to the Waunch Prairie/Davis Hill sewer basin. The area can be served almost entirely with gravity sewers. A new 15-inch-diameter Waunch Prairie gravity interceptor (W-1) provides the backbone for the gravity sewer system and drains into the upper end of the Harrison Interceptor near the intersection of Reynolds and Harrison Avenues, as shown on Figure 5-4. Construction of the Waunch Prairie interceptor will allow elimination of the Reynolds PS, thereby reducing flows into interceptor No. 1. Implementation of this plan requires the construction of the Ford's Prairie Interceptor (F-1) and construction of the Waunch Prairie Interceptor (W-1) beginning at the intersection of Reynolds and Harrison Avenues to North Pearl Street. All costs presented in this section were originally developed in October 2007 dollars and escalated to July 2016 dollars. Table 5-14 summarizes the costs by sewer segment using the designation shown on Figure 5-7. Land uses used for estimating wastewater flows are summarized in Chapter 2. Table 5-14. Waunch Prairie/Davis Hill Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost W-1 Waunch Prairie Interceptor W-1.1 2,760 15 $1,510,000 W-1.2 550 15 $300,000 W-1.3 280 15 $130,000 W-1.4 500 15 $310,000 W-1.5 200 15 $140,000 W-1.6 1,100 15 $920,000 Total $3,310,000 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-37 Table 5-14. Waunch Prairie/Davis Hill Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost W-2 North Pearl Street Interceptor W-2.1 700 15 $500,000 W-2.2 620 15 $440,000 W-2.3 620 15 $440,000 W-2.4 660 15 $360,000 W-2.5 640 15 $350,000 W-2.6 680 15 $370,000 W-2.7 1,480 10 $930,000 W-2.8 1,080 10 $780,000 W-2.9 200 10 $140,000 Total $4,310,000 W-5 Dixon Road and Roanoke Street Area W-5.1 2,000 15 $1,090,000 W-5.2 450 8 $290,000 W-5.3 1,400 10 $610,000 Total $1,990,000 W-6 Southeast Area W-6.1 300 8 $190,000 W-6.2 500 8 $300,000 W-6.3 1140 8 $520,000 W-6.4 300 8 $160,000 W-6.5 540 8 $290,000 W-6.6 360 8 $230,000 W-6.7 720 8 $390,000 W-6.8 360 8 $190,000 Total $2,270,000 W-7 Oakview Avenue Area W-7.1 300 12 $150,000 W-7.2 940 12 $660,000 W-7.3 320 12 $160,000 W-7.4 260 10 $110,000 $88,000 W-7.5 1,000 10 $480,000 W-7.6 1,000 10 $480,000 Total $2,130,000 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-38 BI1212191438SEA Table 5-14. Waunch Prairie/Davis Hill Sewer Extension Projects Line Designation Pipe Length (feet) Pipe Diameter (inches) Total Cost W-8 Carson Street Area W-8.1 640 15 $350,000 W-8.2 940 15 $580,000 W-8.3 640 15 $300,000 W-8.4 1,960 12 $1,300,000 W-8.5 2,320 12 $1,030,000 $801,000 W-8.6 2,300 15 $1,090,000 W-8.7 1,200 10 $580,000 Total $6,030,000 W-9 Sawall and Lowery Area W-9.1 220 8 $140,000 W-9.2 1,020 8 $710,000 W-9.3 940 8 $430,000 W-9.4 120 8 $80,000 $60,000 W-9.5 820 8 $490,000 W-9.6 2,300 8 $1,230,000 Total $3,140,000 N SCALE IN FEET 750 15000 FIGURE 5-7 Waunch Prairie Basin Urban Growth Area City of Centralia General Sewer/Facility Plan WT0621161107SEA Fig5-8_WaunchPrairieUGA_v4 CENTRALIA MAPPING1"=200' SCALE AERIALS25 FT CONTOURS ABOVE ELEV 2005 FT CONTOURS BELOW ELEV 200 Urban Growth Area (UGA) Boundary Sewer Basin Boundary Existing Gravity Sewer Existing Force Main Existing Pump Station New Gravity Sewer New Force Main Line Designation Legend W-1.1 Chehalis RiverW-9.6W-2.9W-9.3W-9.3W-9.3 W-9.2W-9.4W-9.5 W-2.8W-9.1W-2.7W-8.4W-8.5W-8.6W-8.3W-8.2W-8.1W-8.7 W-2.6W-7.5W-7.6W-7.3 W-7.4W-7.2 W-7.1W-2.5W-2.4W-6.8W-6.7W-6.6 W-5.3W-5.2 W-5.1W-2.3W-2.2W-6.3W-6.5W-6.2W-6.4 W-6.1W-2.1W-1.6W-1.5 W-4.3W-4.2W-1.4W-1.3W-1.2W-1.1 W-4.1Low area, Low area,use grinderuse grinderpumps pumps Low area, use grinderpumps Low Lowarea, area,use usegrindergrinderpumps pumps Low area, use grinderpumps Low Lowarea, area,use usegrindergrinderpumps pumps Low area, use grinderpumps Force main Force mainto eitherto eitherForce main to either CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-40 BI1212191438SEA W-1 Waunch Prairie Interceptor The Waunch Prairie Interceptor is a gravity sewer that extends east from the intersection of Reynolds and Harrison Avenues along Reynolds Avenue to North Pearl Street. The portion west of I-5 has been included in the Ford's Prairie sewer basin. The Waunch Prairie Interceptor east of I-5 includes the following: • 5,390 lf of 15-inch sewer The estimated cost of Waunch Prairie Interceptor east of I-5 in July 2016 dollars is $3,310,000. W-2 North Pearl Street Interceptor The North Pearl Street Interceptor extends north along North Pearl Street from Reynolds Avenue to Downing Road. The North Pearl Street Interceptor includes the following: • 3,920 lf of 15-inch sewer • 2,760 lf of 10-inch sewer The estimated cost of the North Pearl Street Interceptor in July 2016 dollars is $4,310,000. W-4 South Reynolds Avenue Area This area includes residential areas south of Reynolds Avenue, bordered by the Skookumchuck River to the south and North Pearl Street to the east. This area is primarily a floodplain. The ground elevations are very low, and it is assumed that grinder pumps will be used to provide sewer service to this area. It is assumed that the grinder pumps and small-diameter force mains will be paid for by the developers of this area, and the costs are not included in the general sewer/facility plan. W-5 Dixon Road and Roanoke Street Area This area includes the area adjacent to Dixon Road and West Roanoke Street. It is assumed that Dixon Road will be extended to West Roanoke Street to allow construction of this sewer alignment. The sewers to serve this area include the following: • 450 lf of 8-inch sewer • 1,400 lf of 10-inch sewer • 2,000 lf of 15-inch sewer The estimated cost of these sewers in July 2016 dollars is $1,990,000. W-6 Southeast Area The southeast area includes areas adjacent to North Tower Avenue and Beach Street and East Roanoke Street. The sewers to serve this area include the following: • 4,220 lf of 8-inch sewer The estimated cost of these sewers in July 2016 dollars is $2, 270,000 W-7 Oakview Avenue Area This area includes areas adjacent to East Oakview Avenue, Sirkka Street, and South Eureka Avenue. These sewers could convey additional flows from the area east of the end of Oakview Avenue that is low and may require grinder pumps. The grinder pumps and small-diameter force mains are assumed to be installed by the developers of this area, and the costs are not included in the general sewer plan. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-41 The sewers to serve this area include the following: • 2,260 lf of 10-inch sewer • 1,560 lf of 12-inch sewer The estimated cost of these sewers is in July 2016 dollars $2,130,000. W-8 Carson Street Area The Carson Street area includes areas adjacent to Carson Street west and east of North Pearl Street and along roads extending north from Carson Street-Seward Avenue, Eureka Avenue and Howard Street. This portion of the Waunch Prairie area is zoned low-density residential. Most of the parcels in this area are already developed. The sewers to serve this area include the following: • 1,200 lf of 10-inch sewer • 4,280 lf of 12-inch sewer • 4,520 lf of 15-inch sewer The estimated cost of these sewers in July 2016 dollars is $6,030,000. W-9 Sawall and Lowery Area This area includes areas along Sawall Avenue and adjoining roads and Lowery Lane. Some flows from the west ridge of Zenkner Valley Road may need to be conveyed to Lowery Lane gravity sewers in the future if the growth management area is expanded to the north. The sewers to serve this area include the following: • 5,420 lf of 8-inch sewer The estimated cost of these sewers in July 2016 dollars is $3,140,000. 5.7.2.4 Widgeon Hill Area Figure 5-8 presents the proposed pump stations, force mains, and gravity sewers to provide sewer service to the Widgeon Hill area. The sewers shown provide the conveyance of wastewater from Widgeon Hill to the existing City sewer system, but do not show the additional collection sewers that will be required to serve the Widgeon Hill area. It is not possible to determine the additional collection sewers at this time, since the area is nearly undeveloped and the collection sewers need to be constructed as development occurs with the area. The medium density residential area at the northern end of Widgeon Hill may best be served by gravity sewers. The very low density residential portion of Widgeon Hill may be best served by grinder pumps and small-diameter pressure sewers, potentially in combination with gravity collector sewers. A gravity collection sewer can serve the northern portion of the Widgeon Hill area. Two new pump stations and force mains are shown to convey wastewater collected at the southern low point to a high point that will be the beginning of the gravity sewer flowing north through the remainder of the Widgeon Hill area. Two pump stations are required, because the elevation difference between the low and high points is 339 feet, and the maximum pumping head for a wastewater pump station is approximately 200 feet. Sewer service to the southern portion of Widgeon Hill requires the construction of the pump stations and force mains and the gravity collection sewer in the northern portion of Widgeon Hill. Costs for construction of sewers to the Widgeon Hill area are summarized in Table 5-15. The costs are in July 2016 dollars. WT0621161107SEA _Fig5-8_WidgeonHillUGA CENTRALIA MAPPING1"=200' SCALE AERIALS25 FT CONTOURS ABOVE ELEV 2005 FT CONTOURS BELOW ELEV 200 N SCALE IN FEET 600 12000 FIGURE 5-8 Widgeon Hill Basin Urban Growth Area City of Centralia General Sewer/Facility Plan CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-43 Table 5-15. Widgeon Hill Sewer Extension Projects Pipeline Length (feet) Pipe Diameter (inches) Cost W01 5,500 8 $2,120,000 W01FM 1,800 8 $640,000 W02FM 3,200 8 $1,140,000 Total pipeline (C.I.P. WH-1) $3,900,000 Pump station No. 1 $523,324 $520,000 Pump station No. 2 $523,324 $520,000 Total pump station cost (C.I.P. WH-2) $1,040,000 Total sewer cost in Widgeon Hill area $4,940,000 The Widgeon Hill area wastewater flows into a portion of the existing Centralia sewer system that is hydraulically overloaded. The existing gravity sewers drain into the Jefferson PS that does not have sufficient capacity for existing flows during extreme wet weather due to I/I. A new gravity sewer alternative was evaluated in concept and appears to be potentially feasible. The gravity sewer will flow from the Widgeon Hill area to the China Creek PS. It will require installation of approximately 12,600 feet of 8- to 24-inch-diameter sewers and have major under crossings of the main north-south railroads and I-5. The cost was originally estimated in October 2007 dollars and escalated to July 2016 dollars. The estimated cost in July 2016 dollars is $14,100,000. This gravity sewer will eliminate the Floral, Jefferson, and Van Buren PSs. Alternatively, the Jefferson PS and force main capacity could be increased or I/I from this area reduced to allow acceptance of additional wastewater flow from the Widgeon Hill area, or a combination of these measures could be implemented. A detailed evaluation of these alternatives is beyond the scope of this evaluation and should be conducted before implementing new sewers to the Widgeon Hill area. 5.7.2.5 Golf Course A new residential area was proposed for the former City golf course between Roswell Road and Seminary Hill, and the City requested an analysis of the projected wastewater flow loading and the impacts to the City's collection system. The developer proposed using grinder pumps to provide sewer service to this area, because the topography of the site made gravity sewers uneconomic and required several pump stations. Flows were estimated for each segment of the proposed system, and the potential for generation of hydrogen sulfide, a malodorous and corrosive gas, was estimated. Since this analysis was completed, this developer is no longer active. A new analysis will be required for future development in this area. This will be completed as development plans are prepared and provided for this area. Maximum flow for this area is estimated to be 15 gallons per minute. The previous developer originally proposed discharging into the closest available gravity sewer, but this would drain into the hydraulically overloaded Jefferson PS. It was recommended that the discharge not be allowed at this location and that the discharge be allowed into the downtown gravity sewers on the western side of the railroad tracks, which would require an under crossing of the railroad tracks. It is estimated that up to 24.5 mg/L of hydrogen sulfide could be generated in the wastewater by the time it reaches the City's gravity sewer system. This will pose a significant odor and corrosion problem for the City at the discharge to the gravity sewer and in the gravity sewer system downstream of the discharge. It is recommended that the developer install a sodium hypochlorite addition system 2,400 feet upstream of the discharge to the gravity sewer system. It is estimated that the sodium hypochlorite dosage will be 240 mg/L and 44 pounds per day at the estimated maximum flow rate and CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-44 BI1212191438SEA use of 12.5 percent hypochlorite solution. It is recommended that the sodium hypochlorite feed system be capable of feeding up to 6 gallons per minute and have a storage capacity of 1,000 gallons. It is further recommended that the City require the developer to pay the City for higher costs associated with the use of grinder pumps. The developer should pay the City for the present worth of adding sodium hypochlorite for the life the sewer system. The City may also be justified in charging a higher monthly service fee for users of grinder pumps, if the City finds that O&M costs of grinder pumps are higher than the rest of the sewer collection system O&M. This is justified because the residents will benefit from the lower initial cost of a grinder pump sewer system in lower home prices, but residents should have to pay for the additional costs associated with use of this type of sewer system. US-4, Ham H/11. Conceptual sewers were designed to serve the existing 87 unsewered residences on Ham Hill, and the conceptual design allows for expansion to serve future growth. Due to the hilly nature of the area, alternatives will need to be developed to convey the sewage to the gravity portion of the sewage collection system. The preferred alternative will need to be approved by the City. The wastewater will discharge to Basin 3. The US-4 conceptual sewer includes the following: • 9,800 lf of 8-inch sewer • 1,300 lf of 4-inch force mains • Alternatives to pump stations that are yet to be determined; these will be provided by the developer The estimated cost for these improvements in July 2016 dollars is $9,660,000. NS-10, South Ham Hill Residential. This collection system will transfer the flows from the residential area along Roswell Road to discharge to Basin 3. A collection sewer will be located in the roadway and drain to a pump station at the western edge of the area. The force main will be routed along North Gold Street to discharge into Interceptor No. 1. The NS-10 conceptual sewer includes the following: • 2,800 lf of 8-inch sewer • New pump station • 2,600 lf of 4-inch force main The estimated cost for these improvements in July 2016 dollars is $3,000,000. 5.7.3 Collection System Recommendations 5.7.3.1 China Creek Interceptor (C.I.P. CC-1) Because of the difference in cost and challenges of providing wetland mitigation to relocate the pipeline, the City will pursue the option of stabilizing the riverbank with riprap to address the exposure of the China Creek force mains. Alternative 2 is no longer being considered. The City completed a portion of the stabilization in 2009 and will need to complete another 1,500 lf in the future. Figure 5-9 shows the approximate limits of the stabilization. This project is considered a high priority project, because loss of the pipeline would cause sewage to spill into the river. The City will proceed with developing an engineering report and preparing the necessary permit applications for this work. The project is expected to require several federal and state permits and approvals covered by the JARPA. Local permits and approvals from the City will also be required. The estimated Class 5 base construction cost is $1,750,000 in 2016 dollars, based on the quantities shown in Figures 5-10 and 5-11 and assuming that riprap is used and that most of the riprap is installed from the riverbank. This cost includes mobilization, bonds, contingency, and sales tax. Total project costs were estimated by adding 30 percent to the base construction costs. This additional cost allowance accounts for design, bidding, services during construction, permits, investigations, and legal and administrative services. At this stage, the expected accuracy level of the base costs shown is minus 30 percent to plus 50 percent. Plummer Lake CHEHALIS RIVERC HEHALI S RI VERChina CreekPump Station SEEDETAIL DETAIL 300 Feet New Riprap 950 Feet New Riprap Existing Riprap N SCALE IN FEET 250 0050 Existing Riprap New Riprap FIGURE 5-9 New Riprap Locations City of Centralia General Sewer/Facility Plan WT0621161107SEA _Fig5-2_NewRiprapLocations ©2013 Google Maps, Imagery ©2013 Digital Globe, U.S. Geological Survey, USDA Farm Service Agency © 2013 Google Maps, Data S10, NOAA, U.S. Navy, NGA, GEBCO Image Landsat FIGURE 5-10 Riprap Cross Section City of Centralia General Sewer/Facility Plan WT0621161107SEA _Fig5-3_RiprapCrossSection_v2 CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-47 5.7.3.2 Centralia Station Development (C.I.P. CS-1) The recommended sewer improvements for the Centralia Station (Alternative 2) are shown on Figure 5-3 in Section 5.3.2 and include the following: Phase 1 • Construct approximately 3,100 feet of new 18-inch-diameter sewer along Borthwick Street and south along Long Road to the existing Long Road PS. The existing force main from Jefferson PS can be connected to this new sewer main near the Alder Street intersection. This reduces its length by approximately 1,000 feet and increases the capacity of the Jefferson PS, due to less pipe friction head loss allowing the pumping rate to increase. • The project construction costs include costs for completing the high-priority improvements to the South Tower, Van Buren, and Jefferson PSs, because the time span between the two project phases is unknown. Phase 2 • Decommission Floral, Ace Auto, Van Buren, and Long Road PSs, and divert approximately 500 gpm flow from Jefferson PS (which would reduce O&M activities). • Upgrade South Tower PS capacity from 80 gpm to 580 gpm and increase wet well depth to 23 feet (existing depth unknown). • Construct a new 1,800-foot-long, 10-inch-diameter force main from South Tower PS. • Construct approximately 550 feet of new sewer up to 10-inch-diameter to collect flows from the new development. • Construct approximately 850 feet of new 12-inch-diameter sewer and 3,200 feet of 10-inch- diameter sewer from Van Buren, Floral, and Ace Auto PSs. This includes a 100-foot bore-and-jack segment with 24-inch-diameter steel casing under the railroad tracks. • Replace approximately 1,450 feet of aged 10-inch-diameter concrete pipe and 900 feet of 8-inch-diameter concrete pipe. • Construct 2,250 feet of new 16-inch-diameter gravity sewer to collect flows from South Tower PS and convey it to the new 18-inch-diameter gravity sewer on Long Road. This includes a 100-foot bore-and-jack section with 30-inch-diameter steel casing under the railroad tracks; properties along South Street (west of the railroad tracks) would be reconnected to the new 16-inch-diameter sewer. A construction cost estimate was developed. The basis of the cost estimate is summarized as follows: • Estimate Date: October 25, 2013 (Updated July 2016) • Accuracy Level: plus 50 percent to minus 30 percent The final costs of the project will depend on actual labor and material costs at the time of bid, actual site conditions, productivity, competitive market conditions, final project scope, final schedule, and other variable factors. As a result, the final project costs will vary from those presented herein. Because of these factors, funding needs must be carefully reviewed prior to making specific financial decisions or establishing final budgets. The construction cost includes mobilization, bonds, contingency, and sales tax. The percentage markups used for this stage of analysis are as follows: • Contractor overhead and profit (in unit costs): 18 percent • Mobilization/demobilization/bonds/insurance/general conditions: 10 percent • Construction cost estimate contingency: 20 percent CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-48 BI1212191438SEA • Escalation to mid-point of construction: Not included • Sales tax (Centralia, WA): 8.0 percent Total project construction costs were estimated by adding 25 percent to the base construction costs. This additional cost allowance accounts for design, bidding, services during construction, permits, investigations, and legal and administrative services. The estimates were originally developed in October 2013 dollars and escalated to July 2016 dollars using the 20-City Average CCIs published by ENR. The costs for upgrading Jefferson, Van Buren, South Tower, and Ace Auto PSs were included in the project construction costs. Table 5-16 shows an itemization of the construction costs in July 2016 dollars. Table 5-16. Summary of Project Construction Costs for Centralia Station Sewer Improvements (Alternative 2) Improvement Cost PHASE 1 Centralia Station Sewers Gravity Sewer Trunk and Miscellaneous Sewer Improvements a $1,920,000 Mobilization/Bond/Insurance/General Conditions $190,000 Contingency (20%) $380,000 Tax (8%) $150,000 Project Cost Allowance (25%) $660,000 Pump Station Upgrades (Jefferson, Van Buren, Ace Auto, South Tower) $580,000 Phase 1 Total Project Cost (C.I.P. CS-1) $3,880,000 PHASE 2 Demo Existing Pump Stations $30,000 South Tower PS Upgrades $210,000 Jefferson PS Upgrades $120,000 Gravity Sewer Trunk and Miscellaneous Sewer Improvements a $1,870,000 Reconnect South Street Services $20,000 Bore and Jack (two locations) $170,000 Mobilization/Bond/Insurance/General Conditions $240,000 Contingency (20%) $480,000 Tax (8%) $190,000 Project Cost Allowance (25%) $830,000 Phase 2 Total Project Cost $4,160,000 ALTERNATIVE 2 TOTAL PROJECT COST $8,040,000 a Unit price includes demolition, earthwork, shoring, asphalt-concrete paving, and manhole installation. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-49 5.7.4 Pump Station Improvement Recommendations (C.I.P. M-1) City staff reviewed the required pump station improvements and developed the following capital improvement program recognizing the needs for high-priority improvements and budget limitations: 2018 • China Creek – This pump station consists of three pumps. One of the original (Wemco) pumps was replaced by a small Vaughan pump to handle dry weather flow. Two of the pumps have been rebuilt, with one spare on the shelf. Improvements needed include purchasing another replacement (Wemco) pump. • Industrial – This pump station is located in a high-traffic roadway and will need to be retrofitted with a new highway-rated lid, new pumps (non-ragging), rails, check valve vault, coatings, and a new electrical panel. This pump station currently serves a small area, and relocation should be considered as part of these improvements. 2019 to 2020 • Borst Park – There is an existing project to line the 21-foot-diameter caisson wet well. The pump station upgrades will include new electrical (to accommodate the other upgrades) and future rewiring of the pump station. • Eshom – Improvements to this pump station include a new coating for the wet well and new electrical panel. Consideration should be given to relocating this pump station as far north on Eshom as possible; this is included in the capital improvement plan. • Galvin and Scheuber – Upgrades will include rebuilding and rechanneling the bottom of the wet well and providing the wet well with a new coating. New electrical panels will also be required. • Jefferson – The wet well for this pump station is undersized, and the City has been operating the existing gravity system under surcharge conditions to relieve cavitation and to provide more capacity. The existing pump station is a wet well/dry well system, and the City is considering switching to submersible pumps for the upgrade of this pump station. • Highland Park – Needed upgrades include a new valve vault and electrical panel. Future Improvements Improvements that will be made after the year 2020 are described as follows: • Gold #2/Ace Auto – This project will require raising the electrical panel at least 5 feet, so that it is above the flood elevation. This work should be completed as soon as possible to protect the electrical system. The pumps will also require replacement in the near future, and replacement of the pumps is included in the costs for upgrading this pump station. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-50 BI1212191438SEA Table 5-17 provides project costs for the 8 pump station improvements. Table 5-17. Pump Station Improvement Project Costs Pump Station Project Costs High Range Low Range Gold #2/Ace Auto $140,000 $210,000 $100,000 Industrial $230,000 $340,000 $160,000 China Creek $330,000 $500,000 $230,000 Jefferson $140,000 $210,000 $100,000 Highland Park $80,000 $120,000 $60,000 Borst Park $90,000 $140,000 $70,000 Galvin and Scheuber $60,000 $90,000 $40,000 Eshom $750,000 $1,200,000 $500,000 Note: Costs are in 2016 dollars. 5.7.5 Inflow and Infiltration Project Recommendations 5.7.5.1 Inflow and Infiltration Pilot Projects (C.I.P. II-1) Figure 5-11 shows the I/I reduction project boundaries and indicates the area where the pilot projects could be performed. Once implemented, these pilot projects will be evaluated to determine which could be cost-effectively applied to a more extensive portion of the sewer system. Because of small project sizes, the ability to quantify the differences in I/I reduction for each technology combination will be limited. Therefore, the comparison between the technologies will be primarily qualitative and will be based on the difficulty of implementation, construction implications, and overall installation performance of the technologies. The qualitative analysis can include the use of point velocity meter interrogations and dip-stick measurements at the downstream limits of the pilot project areas during the wet weather seasons both before and after the installation to assess the impacts of the rehabilitation. Additional qualitative analysis could include a pre-installation closed-circuit television (CCTV) inspection of the sewers during high groundwater conditions to observe the number of leaking defects prior to rehabilitation. Table 5-18 summarizes the pilot I/I project technology combinations selected. Each pilot project could be completed for approximately $540,000 in 2016 dollars. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-51 Figure 5-11. I/I Reduction Project Table 5-18. Pilot I/I Project Rehabilitation/Replacement Technology Combinations Combi- nation Sewer Main Technology Manhole Technology Lateral Tap Connection Technology Lateral Side Sewer Technology Notes 1 CIPP CIP Dig and install compression tap fitting (Inserta Tee) CIPP City staff had limited experience with CIPP. Neighboring utilities had reported problems with CIPP seals at the lateral taps; therefore, replacement tap fittings were preferred. 2 Pipe bursting Dig and replace Dig and install electrofusion saddle Pipe bursting City staff had previous experience with pipe bursting, where the bursting equipment was stalled on buried obstacles and also caused surface heave in isolated locations. 3 Sliplining CIP Dig and install electrofusion saddle Pipe bursting City staff had previous experience with sliplining. Pipe bursting (or CIPP) must be combined with sliplining for the lateral side sewers because of the need to maintain a minimum pipe diameter. 4 SPR-EX CIP Dig and install compression tap fitting (Inserta Tee) CIPP There is currently only one manufacturer for the SPR-EX spiral-wound rehabilitation system, with limited installation history in the Pacific Northwest. CIPP (or pipe bursting) must be combined with SPR-EX for the lateral side sewers because of the need to maintain a minimum pipe diameter. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-52 BI1212191438SEA Table 5-18. Pilot I/I Project Rehabilitation/Replacement Technology Combinations Combi-nation Sewer Main Technology Manhole Technology Lateral Tap Connection Technology Lateral Side Sewer Technology Notes 5 Dig and replace Dig and replace Dig and replace Dig and replace Notes: A more detailed description of the different technologies, their capabilities, and their limitations may be found in the 2010 EPA State of Technology for Rehabilitation of Wastewater Collection Systems Report (EPA, 2010). CIP = cast-in-place CIPP = cured-in-place pipe SPR-EX = spiral-wound pipe renewal (SPR). SPR-EX is an expandable spiral product trade name. 5.8 Alternative Systems Gravity wastewater sewer collection systems are historically the conventional system used within a community. Current minimum sizing for such systems is 8-inch-diameter pipeline, which allows for a wide range of flows. By using the natural terrain and gravity flow characteristics, pumping requirements are minimized. With periodic inspection and cleaning, maintenance is typically minimal on the gravity portion of the collection system. The pump stations require more frequent inspections, cleaning, and general maintenance. During the process of developing this sewer plan, the City considered the use of alternative sewer systems as a means to reduce I/I in the collection system. In general, alternative systems are typically installed at more shallow depths; therefore, high groundwater levels would potentially have a smaller impact on I/I. Refer to Sections 7.2.2 and 9.8 for more information on the requirements for alternative systems. Gravity wastewater collection systems are not typically suitable for low-lying areas where the access points to the pipelines are located above the residences or where groundwater is extremely shallow, thereby increasing the dewatering construction costs and infiltration potential into the sewer system. Depending on the characteristics of the area to be served, alternative wastewater systems may be more appropriate. In the following sections, brief descriptions of alternative wastewater systems are presented along with discussion of potential benefits and issues to be considered. 5.8.1 Septic Tank Effluent Pumping Sewer System A septic tank effluent pumping (STEP) sewer system is a shallow, small-diameter pipeline pressure sewer (force main) that follows the natural profile of the ground. Each sewer service has a septic tank and a small pump to convey the effluent from the septic tank to the small-diameter sewer main. The discharge pipe from each STEP pump to the force main in the street typically ranges from 1 to 1.5 inches in diameter. The force mains in the street range in size from 2 to 6 inches in diameter and are placed 3 to 4 feet deep. Septic tanks remove most of the solids, grit, and grease from the domestic wastewater and provide some anaerobic treatment of the wastewater. Therefore, STEP system pumps can be liquid-only pumps, which are less expensive than pumps designed to handle solids. The electric power supply for STEP pumps typically comes from the home being served by the system. It is often the property owner's responsibility to provide a suitably sized electrical panel and connection in conformance with applicable codes. There is rarely any provision for an alternative electric power source. However, if the home is old, the electrical systems of the home may not conform to current codes. In such cases, the utility may need to have power supplied from a separate source. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-53 If STEP systems are installed in an area with an existing onsite septic system, the existing septic tanks can occasionally be used. However, it is often found that the septic tanks leak, are otherwise defective, or cannot be inexpensively retrofitted for use with a STEP system. Therefore, it is often assumed that existing septic tanks would be replaced with new septic tanks. New side sewers are also frequently constructed from the structure served to the septic tanks to eliminate any existing I/I problems. Replacement of septic tanks and installation of side sewers can disrupt a homeowner's yard and landscaping. Maintenance of STEP systems mainly consists of repairing and replacing the pumping units. Each pumping unit and power supply must be inspected and repaired as needed. Solids also accumulate in the septic tanks and must be removed every 5 to 10 years. There are a number of benefits to STEP systems over conventional gravity or vacuum sewer systems. Because of the shallow depth of the small-diameter pressure mains, the system can usually be constructed with a minimum of excavation, reducing or eliminating the need for expensive dewatering and minimizing the amount of surface restoration required. Because it is a pressure system, the topography of the area is not as critical as for a gravity system. The septic wastewater from a STEP system will be more corrosive and odorous than wastewater from a gravity or vacuum system because of the initial treatment that has taken place in the septic tank. A STEP sewer system also requires more maintenance than a gravity or vacuum sewer because of the large number of individual pumping units and variety of installations. As stated previously, electric power supply is often the homeowner's responsibility. Ecology requires that the utility own, operate, and maintain the STEP system in accordance with Ecology's Criteria for Sewage Works Design document, Sections Cl-1.2 and Cl-10.4 (Ecology, 2019). Therefore, the homeowner must provide the utility with an easement to access the facilities for maintenance and repair. 5.8.2 Low-pressure Sewer System A low-pressure sewer system has small-diameter force mains similar to a STEP sewer system. Low- pressure sewer systems differ from STEP systems, in that each service connection has a small sump and grinder pump instead of a septic tank and a liquids-only STEP pump. Solids are shredded by a 1- to 2-hp grinder pump into a slurry, and the sewage is pumped into the small-diameter force mains. Any existing septic tanks are abandoned. Most of the maintenance of a low-pressure sewer system is in the repair and replacement of the grinder pumps. In particular, the grinder portion of the pump may need frequent replacement, because it becomes dull or is damaged by hard solids. Hard solids can also become lodged in the grinder unit. Frequency of maintenance depends on the quality of the pump. The benefits and considerations of a low-pressure sewer system over a conventional gravity system or vacuum system are essentially the same as those for a STEP system. And as with a STEP system, Ecology requires that the utility own, operate, and maintain the grinder installations. The City desires to standardize around a single manufacturer to minimize the number of spare parts and spare units kept on hand and to minimize the amount of specialized training required to maintain those units. 5.8.3 Vacuum Sewer System A vacuum sewer system has three basic components: the service, the collection piping, and the vacuum station. Wastewater flows by gravity from one or more homes into a vacuum valve pit located on the street right-of-way. Vacuum valve pits consist of a small sump, topped with a vacuum valve that opens when wastewater in the sump rises to a preset level. When the valve is open, vacuum in the main line propels air and wastewater at high velocities from the valve pit into the 4-inch- to 6-inch-diameter vacuum CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-54 BI1212191438SEA mains and toward the vacuum pump station. The vacuum mains are typically 3 to 4 feet deep. The vacuum pump station then pumps the collected wastewater into a standard force main or gravity main to the WWTP. An engine generator can be installed at the vacuum pump station to provide electric power when the normal power supply is interrupted. Power to operate the valves in the vacuum valve pits is taken from the vacuum in the system, so an external power source is not required. The air from the vacuum pump station has minimal odors, primarily because twice as much air as wastewater is allowed into the system each time a valve opens, and travel times to the vacuum pump station are relatively short. For the same reasons, sewage discharged to the gravity system is typically more oxygenated and less corrosive than in a gravity or low-pressure sewer system. Maintenance for a vacuum sewer system consists of inspecting and periodically rebuilding the vacuum valves and maintenance on the vacuum pump station, which is very similar to the maintenance required for an ordinary gravity pump station. Maintenance for a vacuum sewer system is more than for a gravity sewer system (because of the number of vacuum valve pits that must be inspected and maintained) but less than for a low-pressure sewer system. As with a STEP sewer, vacuum sewer systems can be beneficial in areas with unstable soils, flat terrain, and high water tables. According to information presented by the EPA in Alternative Wastewater Collection Systems (EPA, 1991), vacuum systems are most cost-effective with a minimum of 75 to 100 services per vacuum pump station. Because there is so much air in the line compared to the volume of wastewater, sewage discharged to the gravity system is typically more oxygenated and less corrosive than in a gravity or low-pressure sewer system. A significant advantage is also the presence of the central power supply. Topography is a factor to consider in vacuum sewer systems. Typically, the lifting power of a vacuum station is limited to 15 to 20 vertical feet, although this can be incorporated into the overall design. In general, vacuum sewers may be less costly to construct than conventional sewers, but they may also be more expensive to operate and maintain. There are also a limited number of vacuum system manufacturers, so system guarantees are a factor to consider. 5.8.4 Summary Table 5-19 presents a summary of each alternative sewer system, including advantages and disadvantages. Table 5 19. Alternative Sewer System Comparison System Advantages Disadvantages STEP system • Uses liquid-only pumps • Shallow depth reduces construction costs over conventional system • Topography is not critical • Reduced treatment plant costs • Potentially less 1/1 • Power is homeowner’s responsibility • Requires new septic tank • Need to remove solids every 5 to 10 years • Effluent can be more corrosive than systems with septic tanks • Increased collection system odor or odor control costs • Pumps require increased maintenance • Homeowner must provide City with access easement for maintenance and repair Low-pressure sewer • Abandon septic tanks • Shallow depth reduces construction costs over conventional system • Topography is not critical • Potentially less 1/1 • Frequent repair and replacement of grinder pumps needed • Utility must keep large supply of grinder pumps in stock • Homeowner must provide City with access easement for maintenance and repair CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS BI1212191438SEA 5-55 Table 5 19. Alternative Sewer System Comparison System Advantages Disadvantages Vacuum sewer • No external power require source is required • Wastewater is more oxygenated and less corrosive than STEP or low-pressure sewers; fewer odor issues • Beneficial in areas with unstable soils, flat terrain, and high water tables • Central power supply • Potentially less 1/1 • Large number of vacuum valve pits frequent inspection and maintenance • Topography limits vertical lift per vacuum station • More expensive to operate and maintain than conventional systems • Limited number of manufacturers Conventional gravity systems • No power requirements • Utility staff most familiar with operation and maintenance • Few parts required to keep in stock • Less maintenance required than other types of systems After evaluating the alternatives, the decision was made to use conventional gravity systems except where gravity systems are not feasible. The major factor in the decision was the increased operation and maintenance associated with alternative systems, both in terms of equipment cost and increased staff needs. Another factor is that the success of an alternative system depends on the ability of the utility to enforce the program development and equipment requirements; otherwise the system can become problematic, and associated system costs will increase. In the case of the City's sewer system, the advantages of alternative systems did not appear to outweigh the cited disadvantages. 5.9 Application of Alternative Sewer Systems to New Areas It is recommended that grinder pumps be the alternative sewer system allowed when conventional sewer systems are not feasible (see Section 9.8 for more information). It is further recommended that the City standardize on one manufacturer of grinder pumps to facilitate maintenance of grinder pump installations. E/One is currently the manufacturer selected by the City, based on successful application of their equipment. Vacuum sewers may have application for developments of at least 50 connections in the flatter areas where gravity sewer service is feasible, but finances do not permit construction of gravity sewers at the time the City desires an area to develop. STEP systems are not recommended. In undeveloped areas, it does not make sense to construct new septic tanks. STEP systems generate septic wastewater that will create significant odor and corrosion problems when discharged to conventional gravity sewers and also require periodic pumping of solids from the septic tank. These disadvantages make grinder pumps a more attractive alternative when alternative sewer systems are justified. In the Ford's Prairie and Waunch Prairie/Davis Hill areas, gravity sewers can provide service to nearly all the area, and grinder pumps should be limited to a few low-lying areas that cannot be served by conventional gravity sewers. Vacuum sewers could be used to provide service if it is desired to serve larger developments and finances do not allow construction of gravity sewers at the time development is desired by the City. It is not recommended that grinder pumps be allowed to serve isolated development, unless the City stipulates that the development will change to gravity sewers in the future when available, and improvements are made to the conventional sewers receiving grinder pump discharge to deal with odor and corrosion issues. CHAPTER 5 – SEWER COLLECTION SYSTEM IMPROVEMENTS 5-56 BI1212191438SEA Grinder pumps are recommended for individual services in the Cook's and Widgeon Hill very low density residential zoned areas, because they will not allow economical sewer service using conventional gravity sewers. Elevation differences preclude the use of vacuum sewers in most of the areas. Some areas adjacent to gravity collection sewers will allow these areas to be served by gravity sewers. The City will continue to consider the use of alternative systems only where the use of conventional systems is not feasible because of the desire to minimize operation and maintenance costs, which are paid for by all wastewater utility customers. CHAPTER 6 BI1212191438SEA 6-1 Treatment Plant Evaluation This chapter describes the Centralia WWTP discharge standards, reasonable potential analysis (RPA), evaluation of plant capacity, and potential water reclamation and reuse options. It also describes the alternatives analysis to address future growth and planned wastewater treatment improvements. 6.1 Description of Discharge Standards The City currently discharges treated wastewater to the Chehalis River. The following section describes the applicable water quality standards, required treatment plant effluent quality, and potential future treatment requirements. 6.1.1 Applicable Water Quality Standards 6.1.1.1 Regulatory Authority The federal Clean Water Act (1972 and 1977, 1981 and 1987 modifications) established water quality goals for the navigable (surface) waters of the United States. One of the mechanisms for achieving the goals of the Clean Water Act is the NPDES permit, which is administered by the EPA. The EPA has authorized the State of Washington to administer the NPDES permit program. Chapter 90.48 RCW defines Ecology’s authority and obligations in administering the wastewater discharge permit program. The regulations adopted by the State include procedures for issuing permits (Chapter 173-220 WAC), technical criteria for discharges from municipal wastewater treatment facilities (Chapter 173-221 WAC), water quality criteria for surface and ground waters (Chapters 173-201A and 200 WAC), and sediment management standards (Chapter 173-204 WAC). These regulations require that a permit be issued before discharging wastewater to waters of the State. 6.1.1.2 Technology-based Standards (WAC 173-221) Technology-based standards for municipal WWTPs are defined under federal and state regulations. Refer to Discharge Standards and Effluent Limitations for Domestic Wastewater Facilities, Chapter 173- 221 WAC. These are the default standards for domestic wastewater facility discharges and are based on treatment levels that are readily attainable with secondary treatment practices. Technology-based limits for pH, fecal coliform, BOD5, and TSS (WAC 173-221-040) are as follows: • Effluent pH – The effluent pH shall be between 6.0 and 9.0 standard units unless the permittee demonstrates that: – Inorganic chemicals are not added to the waste stream as part of the treatment process; – Contributions from industrial sources do not cause the pH of the effluent to be less than 6.0 or greater than 9.0; and – The discharge does not cause water quality violations outside of an approved dilution zone. • Fecal coliform – Fecal coliform limits shall not exceed a monthly geometric mean of 200 organisms/100 milliliters (mL) and a weekly mean of 400 organisms per 100 mL. • BOD5 and TSS – Except as allowed under WAC 173-221-050, domestic wastewater facilities which discharge to surface waters shall not exceed a 30-day average of 30 mg/L BOD and 30 mg/L TSS. Seven-day averages shall not exceed 45 mg/L BOD and 45 mg/L TSS. Additionally, the 30-day average percent removals of BOD5 and TSS shall not be less than 85 percent of influent concentrations. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-2 BI1212191438SEA 6.1.1.3 Water Quality Standards for Surface Waters Actions related to surface waters must comply with Water Quality Standards for Surface Waters of the State of Washington, Chapter 173-201A WAC, Publication Number 06-10-091 (Ecology, 2017). Protection of surface waters is regulated under the referenced WAC. Ecology amended the Water Quality Standards, which were made effective on December 21, 2006, and EPA approval has been received. The Water Quality Standards protect surface waters by narrative criteria, designated uses, and an anti- degradation policy. Based on the designated uses for a water body, numeric and narrative criteria are assigned to protect the water body’s existing and designated uses. The Chehalis River is designated as requiring aquatic life protection under “salmonid spawning, rearing, and migration” in the vicinity of the outfall (Ecology, 2006). Characteristic uses of this segment of the Chehalis River include the following: • Water supply (domestic, industrial, and agricultural) • Stock watering • Fish migration • Fish rearing, spawning, and harvesting • Wildlife habitat • Primary contact recreation • Sport fishing • Boating and aesthetic enjoyment • Commerce and navigation The Centralia segment of the Chehalis River also has a supplemental spawning and incubation criterion of 13 degrees Celsius (°C) water temperature from October 1 to May 15. Ecology has included the Chehalis River on the federal 303(d) list for not meeting water quality standards for dissolved oxygen, fecal coliform bacteria, and temperature. Total maximum daily loads (TMDLs) have been implemented for each of these to meet water quality standards. 6.1.2 Required Effluent Quality The City’s WWTP has a NPDES permit (Appendix H) from Ecology for discharge of treated wastewater to the Chehalis River. The current permit sets limits on BOD5 and TSS in the effluent as well as limits on fecal coliform, ammonia, and range of pH, as noted in Table 6-1. It is important to note that the loading limits for ammonia, BOD, and TSS presented in Table 6-1 are more stringent than the concentration- based limits. The City was given loading allocations (as reflected in their NPDES permit) in a consent decree in January 2000 (No. C96-5968 RJB). The ammonia loading limit of 110 pounds per day is reflective of a flow rate of 3.3 mgd at the concentration-based permit limit for ammonia. Similarly, for BOD, the effluent limit of 826 pounds per day equates to a flow of 3.3 mgd at the 20 mg/L limit. Table 6-1. Effluent Limitsa at Outfall No. 001 Parameter (at the River Flows Shown Belowf) Monthly Average Weekly Average Daily Maximumb The following parameters apply at the river flows and seasons shown below:c BOD5 and TSS (all seasons) • flows less than 200 cfsc 20 mg/L 30 mg/L, 826 ppd • flows 200 to 1,000 cfsd 20 mg/L, 85% removal of influent BOD5 and TSS 30 mg/L, 926 ppd CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-3 Table 6-1. Effluent Limitsa at Outfall No. 001 Parameter (at the River Flows Shown Belowf) Monthly Average Weekly Average Daily Maximumb • flows greater than 1,000 cfs 30 mg/L, 925 ppd, 75% removal of influent BOD, 70% removal of influent TSS 45 mg/L, 2,530 ppd Ammonia (NH3-N) March 15 to November 30 • flows 200 to less than 1,000 cfsd 4.0 mg/L, 123 ppd • flows less than 200 cfsd 4.0 mg/L, 110 ppd Ammonia (NH3-N) December 1 to March 14d • flows 200 to less than 1,000 cfsd 15 mg/L, 463 ppd • flows less than 1,000 cfs 15 mg/L, 657 ppd The following parameters apply at all flows and seasons: Fecal coliform 200 col/100 mL 400 col/100 mL Copperg Zincg pHd Daily minimum is equal to or greater than 6.0 and the daily maximum is less than or equal to 9.0. a The average monthly and weekly effluent limitations equal the arithmetic mean of the samples taken. The average monthly and weekly limitations for fecal coliform are equal to the geometric mean of the samples taken. b River flows must be determined from the Grand Mount USGS gauge. c The maximum daily effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day. This does not apply to pH. d These "dry weather" limits (for BOD5 and TSS only) apply on the next day after the 7-day moving average flow at the Grand Mound USGS gauge goes below 1,000 cfs and on all subsequent days until the wet weather limits apply. e These “dry weather” limits (for ammonia only) go into effect 14 days after the 7-day moving average flow at the Grand Mound USGS gauge is less than 1,000 cfs. This dry weather limit for ammonia cannot be applied earlier than March 15 of each year following the 14-day phase-in. f Ecology will recalculate final limits for copper in 2015 using water quality data collected by the discharger. g Indicates the range of permitted values. The permittee must report the instantaneous maximum and minimum pH monthly. Do not average pH values. Note: USGS = U.S. Geological Survey 6.1.3 Potential Future Treatment Requirements Effluent quality limits for the parameters in the current NPDES permit, as shown in Table 6-1, are expected to remain unchanged in the future including loading limits. New future regulatory requirements may include advanced treatment to address increasingly stringent river discharge criteria for nutrients. The nutrients reviewed for this General Sewer/Facility Plan were phosphorus and nitrogen. The WWTP does not routinely monitor the effluent phosphorus concentration; however, based on limited data, it appears that the process achieves good phosphorus removal. Phosphorus is a concern in eastern Washington but does not appear to be a near-future concern on the Chehalis River. A CHAPTER 6 – TREATMENT PLANT EVALUATION 6-4 BI1212191438SEA TMDL on the Chehalis River for nitrogen was considered more likely. Upgrades (described in Section 6.6) were considered to reduce nitrogen to 10 mg/L or less for two reasons: • To improve the water quality discharged to the Chehalis River • To facilitate the reuse of the WWTP effluent The City is evaluating conceptual alternatives for reuse of the WWTP effluent as water resources become more limited in the future. It is understood that any future nutrient limits as developed by Ecology would be based on EPA’s technical guidance and recommendations for the nutrient ecoregion and the data submitted by the City as part of the 3-year Receiving Water and Effluent Study and annual summary reports from December 2013, 2014, and 2015. In addition to nutrients, effluent temperature is a concern, as outlined in the 2001 TMDL. As required in the City’s NPDES permit, the City measured effluent and ambient river temperature during the months of April through October for 2013, 2014, and 2015 to enable Ecology to better evaluate temperature effects. Based on the data and discussions with Ecology, a future effluent temperature limit may be required. This is discussed further in Section 6.2. 6.2 Reasonable Potential Analysis A RPA was completed for the Centralia WWTP for inclusion in the General Sewer Plan/Facility Plan (Appendix I). A RPA is used to determine whether a discharge has a reasonable potential to cause or contribute to a violation of Washington state water quality criteria for toxic pollutants. This RPA was requested by Ecology in order to determine whether the WWTP effluent chemistry and updated dilution factors provide compliance with water quality criteria. An evaluation of temperature compliance was also completed. Dilution factors at the designated mixing zone boundaries of the Centralia WWTP outfall have been updated using projected 2035 plant effluent flows. These updated dilution factors have been used to update the RPA for the Centralia WWTP. The results of the RPA concluded the following: • No reasonable potential to exceed water quality criteria was identified for ammonia or metals. • A tentative reasonable potential determination was shown for 18 organic compounds based on non- detect laboratory test results. • A reasonable potential was identified for bis-ethylhexyl phthalate (BEHP) based on the recently revised human health water quality criteria. Sample contamination is the likely source. BEHP is a plasticizer that may be found in sampling equipment such as autosampler tubing and gloves; as such, future testing requiring a detection limit below the human health criteria, with an emphasis on QC procedures to address the potential for sample contamination is recommended. The City will continue to monitor and enforce QC procedures to prevent future sample contamination. Many of the water quality criteria (updated in December 2016) are less than the lowest laboratory detection limits achieved by the priority pollutant scans. A reasonable potential for cyanide was based on a single detection in 2013 that used an incorrect analytical method for evaluating against water quality criteria. A reasonable potential was identified for temperature during the weeks of transition from the summer spawning, rearing, and migration criteria period (17.5° C) to the start of the supplemental salmon spawning period (13.0° C criteria applicable October 1 to May 15), based on river and effluent temperature monitoring data reported by the WWTP in 2013, 2014, and 2015 and updated dilution factors for project WWTP flows for 2035. The calculated incremental mixed temperature increase at the mixing zone boundary during the spring and fall transition periods to the salmon spawning period showed temperature increases greater than 0.3° C, the maximum allowable incremental temperature increase. Further evaluation of temperature compliance needs and mitigation strategies under future CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-5 conditions is planned to address potential temperature limitations as effluent flows increase. Some mitigation, such as partial diversion of effluent flow to irrigation or groundwater recharge, may be required at least during a portion of this transition into the supplemental spawning period (October 1 to May 15). Based on the results of the RPA, two projects were identified for inclusion in the CIP: WW-6, Temperature Compliance Evaluation This detailed study would further evaluate temperature compliance and mitigation alternatives and select a recommended alternative. The estimated cost in 2016 dollars is $60,000. WW-7, Thermal Mitigation Needs After the completion of C.I.P. WW-6, the predesign, design, and construction of the selected alternative can be implemented. A pilot study of the selected alternative could also be completed. The planning level estimate for this C.I.P. item is based on the lowest costs option for meeting thermal mitigation needs of the construction of wetlands for cooling and development of the wetlands for Class C water use as “noncontact recreational or education use with restricted access.” The estimated costs in 2016 dollars for the predesign and design is $1.24 M, while the construction is estimated to be $6.21 M. 6.3 Plant Capacity 6.3.1 Background In 2012 and 2013, analytical results for samples from influent to the Centralia WWTP showed influent BOD5 and TSS loads that exceeded the plant’s rated design capacity multiple times. These apparent exceedances triggered the Ecology requirement that the City develop a plan to show how capacity will be maintained for future loads. This issue was evaluated in two separate analyses. The initial analysis compared the large increases reported in influent BOD5 and TSS loads between October 25, 2011, and March 2013 with the measured MLSS and WAS amounts during that period. It was expected that the MLSS and WAS increased proportionally to influent BOD5 and TSS increases; however, MLSS and WAS had increased only slightly. This analysis concluded that the disparity could be related to replacement of the plant’s influent sampler, which occurred on October 26, 2011. That is, the new sampler could be taking non- representative samples that led to inaccurately high influent BOD5 and TSS results. This led the City to install additional, improved air mixing in the influent channel to reduce stratification and consequent sample variability. The City also performed intensive manual sampling to determine whether the new wastewater sampler was taking representative samples. The City concluded that (1) improved air mixing reduces variability of BOD5 and TSS test results, and (2) average BOD5 and TSS test results were higher when the new sampler with improved air mixing was used than when the old sampler was used. Additional analysis using the test results from samples taken with the new sampler after improved air mixing was implemented concluded that, with improved air mixing, the new sampler is taking representative samples and that the old sampler was obtaining non-representative samples (lower) based on the following: • MLSS and WAS concentrations and quantities predicted by activated sludge process simulations agreed with WWTP observations using the influent BOD5 and TSS measured using samples from the new automatic influent sample with improved air mixing of the influent channel. • Per capita loadings using influent BOD5 and TSS measured using samples from the new automatic influent sample with improved air mixing of the influent channel are closer to the 0.2 ppcd value that is considered typical of municipal wastewater. In light of these results, the City initiated facility planning and an evaluation of plant capacity. The following evaluation was completed to determine the capacity of the plant to treat projected flows and CHAPTER 6 – TREATMENT PLANT EVALUATION 6-6 BI1212191438SEA loads, and prepare a plan to maintain adequate capacity. In the future, the City may further evaluate the plant capacity through a re-rating analysis, as understanding the actual plant capacity is critical to the timing of future WWTP improvements and their associated costs. The City will continue to collect and monitor data for technical validation of the current actual plant capacity. The capacity of each treatment process (including the headworks screens, aeration basins and secondary clarifiers, UV disinfection system, effluent pumps, and solids handling) was reviewed and compared to projected flows and loads. Table 6-2 presents the 2015 plant influent values, the permitted capacity, and projected 2035 influent flows and loads. For 2015, the plant was at 86 percent of the maximum month BOD loading capacity and 106 percent of the maximum month flow capacity. Table 6-2. Capacity Summary Parameter 2015 Base Year NPDES Permit Capacity 2015 % of Capacity 2035 Projected Influent Value Maximum Month BOD5 (ppd) 3,776 4,400 86 5,860 Maximum Month TSS (ppd) 3,973 5,000a 79 6,165 Maximum Month Flow (mgd) 5.82 5.5 106 7.46 Maximum Day Flow (mgd) 8.67 8.6 101 10.70 Peak hour/instantaneous peak flow (mgd) 9.1 9.3 98 11.44 a As approved in the 2014 General Sewer Plan Update 6.3.2 Capacity Evaluation Results 6.3.2.1 Headworks Screening and Grit Removal (WW-3) The screening facility consists of two quarter-inch rotary screens with a capacity of 5 mgd each. Based on the existing flow data presented in Chapter 3, the screens have adequately passed the highest peak hour flow recorded from 2011 to 2015 of 9.1 mgd. The screens also successfully passed 11.75 mgd during the February 5, 2005, hydraulic performance test. An additional screen will be required as flows increase to the WWTP. This is included in the C.I.P. Aeration Basins and Secondary Clarifiers As shown in Table 6-2, the projected 2035 flow and loads exceed the plant’s rated capacity. Thus, the existing two aeration basins and secondary clarifiers are inadequate for future 2035 flows and loads. A calculation of the aeration needs estimated a required 5,000 standard cubic feet per minute (scfm) air rate, which is less than the 6,400 scfm blower system firm capacity. These calculations are provided in Appendix J. The plant has demonstrated adequate aeration capacity as well. According to plant staff, only one unit out of the three blowers is needed most of time. This agrees with the historical plant data on the daily air flows, which are presented in Appendix J. As shown in Appendix J, the maximum daily air flow recorded was 3,419 scfm, just slightly higher than the rated blower capacity of 3,200 scfm. Since current maximum month loads correspond to 80 to 85 percent of the plant’s rated capacity, the existing three blowers would be adequate for the rated plant capacity. 6.3.2.2 Dewatering The plant has a 2-meter belt filter press with a capacity of 682 pounds per hour per meter (lbs/hr/m), within the 400 to 700 lbs/hr/m range recommended by the Manual of Practice (Water Environment Research Foundation, 2003). Currently, the plant does not have dedicated solids holding volume, and WAS is dewatered two to three times per week. The belt filter press would need to be operated 3 to CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-7 4 days per week, assuming an 8-hour shift, to accommodate future projected plant loads. The plant is able to accommodate scheduled downtime between dewatering periods. 6.3.2.3 Solids Stabilization The Centralia WWTP has two solids stabilization processes: composting (primary) and lime pasteurization (secondary). The existing composting process capacity is 3,500 pounds per day (lbs/d) dry solids and the lime pasteurization process can handle 1,100 pounds per hour dry solids or 8,800 lbs/d (8-hour operation). No redundancy is required for either process. Projected WAS production at 7.5 mgd maximum month flow is approximately 5,600 lbs/d dry solids. This is well within the rated combined capacity of the two stabilization processes. 6.3.2.4 Disinfection The UV disinfection system consists of three channels. Each channel has a low-pressure high-output UV bank. Based on plant experience, the UV system provides adequate disinfection at the rated flow of 5 mgd per channel (10 mgd firm capacity; 15 mgd total). The UV system design criteria is 30 millijoules per square centimeter with a UV transmittance of 65 percent. The February 2005 stress test passed 11.75 mgd through 2 UV channels. The results showed that transmittance decreased significantly when the flow was suddenly increased, contributing to higher effluent fecal coliform in the effluent; however, transmittance improved as the test continued. The geometric mean for flow over 3 mgd was 96. The NPDES permit states that the fecal counts cannot exceed a monthly geometric mean average of more than 200 or a weekly geometric mean of 400. Since the geometric mean was less than 100, the test showed that the UV system performed well within the permit limits. The plant has not experienced any permit violations for effluent fecal coliform. The plant has operated individual channels at their maximum hydraulic capacity for very short durations. Typically, operators are more conservative and bring a second channel online when flows are sustained at 4 mgd or higher. The following major UV system alarms are in place to alert operators to situations where disinfection may be reduced: • Low UV Intensity Alarm • Individual Lamp Alarm Failure Alarm • Multiple Lamp Failure Alarm • Module Failure Alarm • Programmable Logic Controller (PLC) failure • Communication System failure • Bank failure to energize • Loss of power to the System Control Center • Incomplete sequence 6.3.2.5 Effluent Pumping The Centralia WWTP has three submersible, variable speed effluent pumps that pump effluent to the outfall at periods of high river water levels. Each pump is rated at 5 mgd. The February 5, 2005, hydraulic performance test demonstrated that the plant has a sufficient hydraulic capacity to pass through 11.75 mgd peak flow by gravity, at a river water level of 135-foot elevation, which exceeds the projected maximum peak hour flow of 11.44 mgd. Typically, effluent will need to be pumped at the peak hour flow by the three existing pumps. Although each pump is rated at 5 mgd, examination of the pump curve and friction losses experienced during the February 5, 2005, hydraulic performance test results, coupled with analysis of pump discharge losses, show that two pumps can pump up to 11.3 mgd at the river level corresponding to the 100-year flood event, with the third unit serving as standby. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-8 BI1212191438SEA 6.3.2.6 Backup Power The plant has one standby generator with a capacity of 1 megawatt. This is sufficient to provide power to the entire plant at full operating conditions. 6.3.2.7 Redundancy Analysis The plant was also evaluated for plant redundancy requirements per the Orange Book (Ecology, 2008) as shown in Table 6-3. Table 6-3. Centralia WWTP Redundancy Requirements Reliability Class II Requirementa, b Centralia WWTP Mechanically Cleaned Bar Screens. A backup bar screen, designed for mechanical or manual cleaning, must be provided. Facilities with only two bar screens must have at least one bar screen designed to permit manual cleaning. The plant has one backup bar screen designed for manual cleaning. Pumps. A backup pump must be provided for each set of pumps performing the same function. The capacity of the pumps must be such that, with any one pump out of service, the remaining pumps will have the capacity to handle the peak flow. The plant has the following pumps: • RAS pumps: Quantity 4; 950 gpm capacity each or 3,800 gpm total; 2,750 gpm total peak RAS rate flow • Effluent pumps: Quantity 3; Nominal 5 mgd capacity each; based on the hydraulic analysis, two pumps can pass 11.75 mgd • WAS pumps: Quantity 2; 350 gpm capacity each. The plant does not need to continuously waste during peak flow. The plant typically operates the WAS pumps about two times per week, with peak wasting volumes corresponding to a daily average WAS flow of approximately 45 gpm. Final Sedimentation Basins The units must be sufficient in number and size so that, with the largest-flow-capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the design basin flow. The plant has two 3,848 sf secondary clarifiers, each with a peak day overflow rate of 1,200 gpd/sf or 4.6 mgd capacity. Total maximum month design flow: 5.5 mgd per original design 50% of total design flow: 2.25 mgd per original design Activated Sludge Process Components. 1. Aeration Basin. A backup basin will not be required; however, at least two equal-volume basins must be provided. 2. Aeration Blowers or Mechanical Aerators. There must be a sufficient number of blowers or mechanical aerators to enable the design oxygen transfer to be maintained with the largest-capacity-unit out of service. It is permissible for the backup unit to be an uninstalled unit, provided that the installed units can be easily removed and replaced. However, at least two units will be installed. 3. Air Diffusers. The air diffusion system for each aeration basin must be designed so that the largest section of diffusers can be isolated without measurably impairing the oxygen transfer capability of the system. 1. The plant has two aeration basins of 0.9 million gallons each. 2. There are three aeration blowers each with a capacity of 3,200 scfm; firm capacity is equal to 6,400 scfm. Calculated air demands at 6.0 mgd are equal to 6,362 scfm. 3. Each basin has two diffuser sections each with its own control valve. CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-9 Table 6-3. Centralia WWTP Redundancy Requirements Reliability Class II Requirementa, b Centralia WWTP Disinfectant Contact Basins. The units must be sufficient in number and size so that, with the largest-flow-capacity unit out of service, the remaining units will have a design flow capacity of at least 50 percent of the total design flow. The plant has three UV channels with a capacity of 5 mgd each. With one channel out of service, the two remaining channels can handle the peak flow of 10 mgd. a Per Orange Book Table G2-9. General Requirements for Each Reliability Classification (Ecology, 2008) b Communition Facility and Primary sedimentation basins and trickling filters not applicable 6.3.3 Capacity Summary Figure 6-1 shows a summary of the process capacity for each treatment process as presented in the previous section. This shows that the current plant process capacity is 5.5 mgd, as limited by the secondary treatment process. The hydraulic capacity (peak hour) is 9.3 mgd, as limited by the secondary clarifiers. Peak flows do continue to be a concern. The highest maximum month flow experienced by the plant was in December 2015 (5.7 mgd per the plant DMR). From December 7, 2015, to December 8, 2015, influent plant flow more than doubled (from 3.78 mgd to 7.73 mgd), corresponding to an increase in Chehalis River flows to record levels. The average TSS removal was 75 percent in December 2015, though the concentration limits were not exceeded. The City has an ongoing I/I reduction program, as described in Chapter 5, to reduce I/I flows to the plant and consistently meet 85 percent removals of TSS and BOD. Figures 6-2 and 6-3 show projected flows and loadings along with the revised plant capacity. As shown, in order to accommodate future growth, improvements will be required to expand the capacity of the WWTP. If the population increases as described in Chapter 2, the WWTP hydraulic capacity will be exceeded in 2024, and the plant loading will be exceeded in 2026. The City will closely monitor influent flow and loading on a yearly basis to verify influent assumptions presented in this General Sewer/Facility Plan. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-10 BI1212191438SEA Note: Dewatering capacity is based on 5 days per week, 8 hours per day operation. Figure 6-1. Process Capacity Summary 5.5 5.5 10 13.9 19.9 10 10 10 9.3 15 11.3 0 2 4 6 8 10 12 14 16 18 20 Screening Grit Removal Aeration Basins Secondary Clarifiers UV Disinfection Effluent Pump Station Dewatering Solids StabilizationPlant Flow, MGDAverage Maximum Month Peak Hour Average maximum month capacity rating = 5.5 mgd Peak hour capacity rating = 9.3 mgd CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-11 Figure 6-2. Projected Loading versus Proposed Capacity, Maximum Month 3000 3500 4000 4500 5000 5500 6000 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035Maximum Month Loading, ppdYear Projected BOD Loading, ppd Projected TSS Loading, ppd BOD Capacity, ppd TSS Capacity, ppd CHAPTER 6 – TREATMENT PLANT EVALUATION 6-12 BI1212191438SEA Figure 6-3. Projected Flow versus Proposed Capacity, Maximum Month 4 5 6 7 8 9 10 11 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035Plant Flow, mgdYear Projected Max Month Flow, mgd Max Month Flow Capacity, mgd Projected Peak Day Flow, mgd Peak Day Flow Capacity, mgd CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-13 6.4 Alternatives Analysis As shown in Section 6.3, WWTP upgrades are needed by 2024 to increase plant capacity and meet the effluent limits defined in the City’s current NPDES permit. Three alternatives were considered to provide the additional secondary treatment capacity required. The potential for each alternative to meet future potential nutrient removal requirements was also considered. Table 6-4 presents the future (year 2035) design flows and maximum month loads and is followed by a description of other key inputs used in the process evaluation. Table 6-1 shows the City’s current effluent limits, which dictated the design effluent quality that each alternative had to meet. Table 6-4. 2035 Design Flows and Loads Centralia WWTP Parameter Design Value Flow Average Annual 3.04 mgd Maximum Month 7.46 mgd wet weather 2.1 mgd dry weather Maximum Day 10.70 mgd Peak Hour 11.44 mgd Maximum month BOD 5,860 lbs/d wet weather 5,430 lbs/d dry weather Maximum month COD 12,550 lbs/d wet weather 11,640 lbs/d dry weather Maximum month TSS 6,160 lbs/d wet weather 6,220 lbs/d dry weather Maximum month VSS 5,670 lbs/d wet weather 5,720 lbs/d dry weather Maximum month TKN 1,490 lbs/d wet weather 1,360 lbs/d dry weather Maximum month ammonia 840 lbs/d wet weather 940 lbs/d dry weather Minimum temperature 11.5 degrees Celsius Notes: TKN = total Kjeldahl nitrogen VSS = volatile suspended solids Key operating criteria used in the evaluation are described as follows: • Influent maximum month concentrations were projected based on historical data. Future wastewater characteristics are anticipated to be the same as the existing characteristics. • A conservative average effluent ammonia-N goal of 0.5 mg/L was targeted to facilitate reliable compliance with the maximum daily effluent ammonia permit limits of 4 mg/L for summer and 15 mg/L for winter and to avoid partial nitrification that may result in unstable plant operations. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-14 BI1212191438SEA • Influent wastewater characteristics from available plant data and influent COD fractionation, as well as kinetic and stoichiometric parameters for heterotrophs and nitrifiers selected from published ranges (Metcalf & Eddy, 2014), were used to predict the MLSS concentration in the aeration basins. Parameters were selected based on the best correlation to actual WWTP data during three periods of relatively steady operations: July to November 2014, July to October 2015, and March 2015. Steady operations were primarily judged by consistent plant influent loading and temperature, effluent quality, number of aeration basins in service, and operating solids retention time (SRT). 6.4.1 Alternative 1 – Third Aeration Basin Alternative 1 consists of adding a third 0.9-MG aeration basin, a third 70-foot-diameter secondary clarifier, and WAS storage tanks. These structures would be the same dimensions and capacity as the existing facilities. The WAS increase as growth occurs can be managed by the existing belt filter press and composting system. It will require longer operational hours or 1 additional day of processing. The addition of WAS storage tanks to the plant is discussed in Section 6.5.1. Advantages of this alternative include the following: • The plant site has space available for future facilities. • Facility locations for aeration basin and secondary clarifier are already identified as part of original WWTP site planning and design. • The plant process is the same as the existing process. • The City can continue composting for solids processing. • The visual impact is lower relative to the other two alternatives. Disadvantages of this alternative include the following: • Aeration demand is higher; energy requirements are higher relative to Alternative 2. • The biological treatment process is subject to influent loading variability. To meet potential future nutrient requirements, the existing aeration basins would need to be modified. A swing zone would be added after the anoxic zone by constructing a new baffle wall in the first portion of the aerobic zone. Submersible mixers would be added to maintain solids suspension in the swing zone. 6.4.2 Alternative 2 – Primary Clarifiers and Anaerobic Digester Alternative 2 includes adding two 50-foot-diameter primary clarifiers, a third 70-foot-diameter secondary clarifier, two 25-foot-diameter gravity thickeners, two 106,000-gallon anaerobic digesters, and two new gravity belt thickeners to meet future growth needs. The addition of primary clarifiers and gravity thickeners was the original planned for the first phase of expansion when the plant was designed. The addition of primary clarification would generate raw primary solids. Originally, the City had planned to incinerate the raw primary solids that would be generated if primary clarification were added. Instead, lime stabilization was implemented as an interim solids-handling process. Recently, the City implemented aerated static pile composting. Composting of raw primary solids is not recommended, because dewatering and handling of raw primary solids presents serious odor and potential health issues for O&M staff. Thus, this alternative includes adding anaerobic digestion to process solids to a Class B product. Gravity thickeners and gravity belt thickeners would be added to thicken the primary solids and WAS, respectively, prior to digestion. Following digestion and dewatering (using the existing belt filter presses), the dewatered biosolids would be composted in the existing composting facility to create a Class A product, similar to the existing product. CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-15 Advantages of this alternative include the following: • Space is available for future facilities. • Locations are already identified for primary clarifier, secondary clarifier, and gravity thickener facilities as part of original WWTP site plan. • The City has greater ability to accommodate longer-term expansion. • Variability of influent loading for the biological treatment process is reduced. • Energy requirements are lower, and it allows for energy recovery from digestion process. Disadvantages of this alternative include the following: • Staff must learn a new solids handling process. • Anaerobic digestion is a mechanically complex operation. • O&M cost is higher. • Initial capital cost is higher. • Visual impact from digester tanks is higher. To meet potential future nutrient requirements, the existing two aeration basins would need to be modified as described in Alternative 1. A new swing zone would be created and mixers installed to maintain solids suspension. 6.4.3 Alternative 3 – Membrane Bioreactor This alternative consists of adding a 4-mgd membrane bioreactor (MBR) to the WWTP and converting part of the secondary treatment facilities to treat flow via the MBR instead of the conventional activated sludge process. It is assumed that two-thirds of the plant flow would be treated by the MBR process and the remaining one-third by the conventional activated sludge process, to maximize use of existing facilities while still providing capacity for growth. MBR effluent flow would be blended upstream of disinfection. The blower building would be expanded to accommodate new blowers for the MBR. A new chemical facility including chemical storage and distribution would also be required to maintain the membranes. Fine screens would be added for the primary effluent feeding the MBR process to protect the membranes. The additional WAS increase as growth occurs can be managed by the existing belt filter press and composting system; however, it will require longer operations hours or 1 additional day of processing. Advantages of this alternative include the following: • Less space is required, and the footprint is retained for future facilities. • It achieves a higher level of treatment with greater ability to meet potential future more stringent treatment requirements and to produce Class A water for reuse without the addition of tertiary filters. Disadvantages of this alternative include the following: • It is a more complex operation than conventional activated sludge. • Two secondary treatment processes must be operated in parallel. • Chemical addition is required. • It has the highest initial capital cost. • It has higher energy requirements. • It has higher O&M costs. Like the two other alternatives, modifications to add a swing zone to the existing aeration basins would be needed to meet potential future nutrient requirements. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-16 BI1212191438SEA 6.4.4 Alternative Comparison All three alternatives can be implemented within the existing plant site and would thus have comparable, minimal environmental impacts. Impacts to the public are also comparable among the alternatives. Visually, the facilities would be set back from the public access road, and all would be designed to maintain consistency with the plant’s architectural theme. Table 6-5 shows the matrix comparison of the three alternatives. Table 6-5. Alternative Comparison Matrix Criteria Alternative 1 – Third Aeration Basin Alternative 2 – Primary Clarifiers and Digestion Alternative 3 - MBR Footprint required 0 0 + Ability to meet current effluent limits + + + Ability to accommodate potential future nutrient removal + + + Operational complexity + - - Energy required - + - Level of maintenance + - - Environmental impact 0 0 0 Public acceptability 0 0 0 Odor impact 0 0 0 Visual impact 0 - 0 Capital Cost + - - Notes: - = negative or worse compared to other alternatives + = positive or better compared to other alternatives 0 = neutral compared to other alternatives Comparing the advantages and disadvantages of each alternative, Alternative 3 – MBR is the least desirable alternative, because it requires the City to operate two different treatment processes in parallel. It also has the highest initial capital cost and adds a great deal of mechanical complexity to the plant. Although an MBR can provide a higher level of treatment than the other alternatives, this level of treatment is not required by the current permit limits, and the other alternatives can also be adapted to meet potentially more stringent effluent requirements in the future. It has a slightly smaller required footprint but also includes the addition of unplanned facilities such as chemical storage, the MBR tank, and a fine screen facility. Alternative 3 has no other significant advantages over Alternatives 1 and 2. Based on this, Alternative 3 was removed from further consideration. Alternatives 1 and 2 were carried forward for further evaluation. Class 5 capital cost estimates as defined by the Association for the Advancement of Cost Engineering International were developed for both alternatives. Annual O&M costs were developed for both, including labor for operations and routine maintenance, equipment, and electricity. Life-cycle costs were developed for each alternative based on a 50-year project life and a 20-year life for primary equipment. The capital, annual O&M, and life cycle costs developed for each alternative are shown in Table 6-6 for comparison. CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-17 Table 6-6. Alternative Cost Comparison (2016 dollars) Item Alternative 1 Alternative 2 Capital (Project) Cost $10,910,000 $20,308,000 Annual O&M $147,000 $161,000 Life Cycle Cost $13,540,000 $22,890,000 6.4.5 Selected Alternative Alternative 1 – Third Aeration Basin, has the lowest capital and life cycle costs and meets WWTP capacity needs for the planning period. Therefore, Alternative 1 is the selected alternative to increase plant capacity. 6.5 Recommended Wastewater Treatment Plant Upgrades Section 6.4 described the alternatives analysis process to address longer-term plant capacity needs. The City also identified desired improvements to benefit operations in the near-term. Therefore, two phases of major plant upgrades are recommended: Phase I to add operational flexibility for the near term and Phase II to address capacity needs for the longer term. This section describes the recommended improvements for both. 6.5.1 Phase I (C.I.P. WW-1) Phase I WWTP process upgrades will include adding mixed liquor recirculation in the aeration basins and dedicated WAS storage tanks to increase operational flexibility and optimize the existing WWTP capacity. These items were included in the approved 2000 Facilities Plan and then removed during the original plant design and deferred as future improvements due to budget constraints (CH2M, 2000c). Phase I upgrades will include the following: • Installing mixed-liquor recirculation (MLR) pumps in the existing aeration basins to pump mixed liquor from the end of the aeration basins to the beginning (anoxic zone) of the aeration basins • Improving solids handling by installing WAS storage tanks: WAS will be pumped from the secondary clarifiers to the WAS tanks for storage, then pumped from storage to the BFP for dewatering • Installing new positive-displacement blowers in the existing blower building to provide aeration for the WAS storage tanks • Expanding the existing blower building to provide a second electrical room (electrical annex) to allow for expansion of the existing motor control center (MCC) and remote input/output (I/O) racks to supply power and control to the Phase I equipment The General Sewer Phase I Improvements Plans and Specifications (100 percent design documents), dated August 2018, were approved by Ecology on August 29, 2018. 6.5.1.1 Mixed-liquor Recirculation The addition of MLR in the aeration basin will provide alkalinity recovery and reduction in oxygen demand. The required MLR rate for alkalinity recovery depends on influent characteristics such as TKN, ammonia, and alkalinity concentrations. During the Phase I design, the plant collected influent samples for TKN, ammonia, alkalinity, BOD, and TSS analyses in both dry and wet weather seasons. The sampling results, along with available historical data, were used for a sensitivity analysis that investigated the effect of CHAPTER 6 – TREATMENT PLANT EVALUATION 6-18 BI1212191438SEA varying influent characteristics, in particular TKN and alkalinity levels, on effluent alkalinity to inform the MLR pump sizing. The data showed an influent TKN range of 13 mg/L to 58 mg/L, and an influent alkalinity range of 75 mg/L to 241 mg/L. The higher concentrations occurred in the dry-weather season as a result of little dilution from I/I. The MLR rates were selected by trial and error for wet weather maximum month (WWMM) and dry weather maximum month (DWMM) design conditions to optimize the denitrification in the anoxic selectors. A further increase in MLR rates would result in diminishing benefits and increasing risk of oxygen inhibition at the selectors. WWMM and DWMM conditions for optimized MLR are as follows: • WWMM: Design flow of 5.5 mgd and MLR rate of 100 percent • DWMM: Design flow of 1.7 mgd and MLR rate of 170 percent In total, 1,100 lbs/d influent TKN was used per 2002 design criteria, which is likely higher than actual TKN loading. (Influent sampling results showed the TKN to BOD ratios maximized at 22 percent, or 968 lbs/d TKN for the permitted 4,400 lbs/d BOD loading, and averaged at 16 percent, or 704 lbs/d TKN for the permitted 4,400 lbs/d BOD loading.) Table 6-7 confirms that the selector sizing and MLR rate are adequate for optimizing the existing selector performance, as measured by alkalinity recovery and effluent nitrate level. A 100 percent MLR rate for the WWMM condition would recover 36 mg/L alkalinity; achieve 6.9 mg/L effluent nitrate-N and 1.5 mg/L effluent ammonia-N; and save approximately 17 percent of the oxygen demand. In the DWMM condition, even with one train out for maintenance, the MLR rate achieving optimal denitrification (approximately 170 percent MLR rate) would recover 145 mg/L alkalinity as calcium carbonate (CaCO3); achieve approximately 17 mg/L effluent nitrate-N and 0.9 mg/L effluent ammonia-N; and save 21 percent of the oxygen demand. The design MLR rate was selected at 4,000 gallons per minute (gpm), which enables optimal alkalinity recovery for the 5.5-mgd wet-weather maximum month design flow. Two 2,000-gpm pumps equipped with variable-frequency drives (VFDs) will be installed, one at each aeration basin. The size of the proposed MLR pumps (2,000 gpm) is roughly the same size as the MLR pumps indicated in the approved Wastewater Treatment Plant Facilities Plan (1,900 gpm). The MLR rate can be turned down to about 200 percent of 1.7-mgd dry-weather maximum month influent flow (or 2,400 gpm), to optimize alkalinity recovery in the dry-weather season, if both pumps and both aeration basins operate. The MLR rate can be further turned down during DWMM conditions, by operating only one aeration basin and one MLR pump, thus allowing the MLR rate to be further turned down to approximately 100 percent of DWMM flow. If nitrogen removal is required in the future, an MLR rate of 700 percent or greater in dry weather season and 300 percent or greater in wet weather season would be needed, depending on the actual effluent nitrogen permit limit and influent TKN load. Upsizing the MLR pumps during Phase I to meet potential future nitrogen removal requirements would result in oversized pumps that could not be turned down to the optimal MLR rate required for alkalinity recovery in Phase I. This may lead to a lower effluent alkalinity and potentially poorer effluent quality. The technical memorandum Centralia WWTP Phase 1 Improvements Design – Supplemental Calculation and Responses to May 2018 Ecology Comments and supplemental calculations were provided to Ecology, which contain additional detailed information regarding this anoxic selector evaluation and the aeration basin air diffusers. CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-19 Table 6-7. Design Summary for Anoxic Selector/MLR Sizing Parameter Unit WWMM DWMM Effluent Ammonia-N mg/L 1.5 0.9 Effluent Nitrate (NO3) -N mg/L 6.91 17.43 Internal Recycle Ratio Unitless 1.0 1.7 RAS Recycle Ratio Unitless 0.48 0.68 Anoxic Volume m3 954 477 Mixed liquor suspended solids (MLSS) grams per m3 2,900 3,640 Overall Specific Denitrification Rate g/g NO3/MLVSS 0.13 0.18 Detention Time Hours 1.1 1.8 Reduction in Oxygen Demand Percent 17.2 21.2 Mixing Power Kilowatt 11 6 Alkalinity Recovery mg/L 36 145 6.5.1.2 Waste Activated Sludge Storage Tank Currently, the City uses a portion of the aeration basins and secondary clarifiers to store the WAS generated. New WAS storage tanks will allow daily wasting of activated sludge solids on a continuous basis. This will eliminate the need to store sludge in the aeration basins and clarifiers, which will minimize the MLSS-concentration fluctuations in the aeration basins, provide flexibility in operations, and maximize secondary treatment process capacity. Two WAS storage tanks are proposed providing approximately 4 days of storage in total, which allows for storage over a long weekend without needing to dewater (Table 6-8). The existing belt filter press feed pumps, which are oversized for continuous WAS wasting, will be relocated to the new WAS storage tanks to convey WAS from the WAS storage tanks to the belt filter presses. Two new smaller WAS pumps will be installed in the existing WAS wet wells to waste WAS more continuously from clarifiers to the WAS storage tanks. The WAS storage tanks will be aerated to prevent development of a septic condition and associated odor. Coarse bubble diffusers will be used for tank aeration. The aeration will be intermittent to allow denitrification to occur and remove at least 50 percent of the nitrate produced from the nitrification in the tanks. The goal is to minimize the nitrogen load in the belt filter press filtrate that will be recycled to the WWTP, as well as to minimize alkalinity consumption at the WAS storage tanks. Better denitrification performance has been observed in similar processes at other facilities when operated properly. Mixers will be installed to keep the sludge in suspension to improve denitrification during the unaerated period. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-20 BI1212191438SEA Table 6-8. Waste Activated Sludge Tank Design Criteria Summary Tank Parameters Values Number of Tanks 2 Volume (million gallons, each) 0.1 Dimensions (feet, length by width) 26 x 26 Side Water Depth (feet) 20 Maximum Month Total Sludge Storage (days), if no decanting if decanting full tank by 5 feet prior to feeding BFP 3.9 (dry weather) 4.2 (wet weather) 5.2 (dry weather) 5.6 (wet weather) Maximum Month WAS Flows (gpd, per process modeling) 51,463 (dry weather) 47,964 (wet weather) WAS Concentration (mg/L) 8,000 to 10,000 prior to decanting, 10,000 to 15,000 or higher after decanting The WAS TSS concentration in the WAS storage tank effluent is expected to range from 8,000 to 10,000 mg/L, about the same as the WAS TSS withdrawn from the clarifiers. The City indicated that the BFP performs best at feed solids of 2.0 percent or higher, with a preferred minimum solids concentration of 1.0 to 1.5 percent. To achieve a higher feed solids to facilitate BFP operation, a telescoping valve was included in the Phase I design at each WAS storage tank, which will allow decanting. With the anticipated WAS TSS of 8,000 mg/L to 10,000 mg/L, which can be achieved by adjusting the RAS rate, decanting 5 feet of supernatant after the tank is full is expected to raise the WAS solids content to between 1.0 and 1.5 percent. A thicker WAS feed to the belt press can be obtained by additional decanting, or by lowering the RAS rate, which would result in a higher WAS TSS concentration. 6.5.1.3 WAS Blowers Two new positive-displacement blowers (540 scfm capacity each with VFDs) will be used to aerate and mix the WAS storage tanks, with one unit dedicated to each tank under normal operation to allow for independent WAS storage tank operation. If one blower needs maintenance and is out of service, the remaining blower will be sufficient to aerate and mix the contents in both WAS storage tanks at a mixing intensity of 20 scfm per 1,000 cubic feet. In this mode, the interconnecting gate between the two WAS storage tanks will need to be opened to equalize the WAS levels between tanks. These blowers will be installed along the western wall in the existing blower building. 6.5.1.4 Electrical Annex The existing blower building will be expanded to the west to provide a second electrical room (electrical annex) to allow for expansion of the existing MCC and remote I/O racks to supply power and control to the Phase I equipment. The electrical annex will be approximately 13-feet by 30-feet. 6.5.2 Phase II (C.I.P. WW-5) Phase II improvements for the WWTP to meet capacity needs through year 2035 consist of the selected Alternative 1 – Third Aeration Basin. Further improvements required to meet future potential nutrient removal requirements are also described in this section. CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-21 6.5.2.1 Improvements to Increase Plant Capacity Process-capacity driven improvements include a third aeration basin, a third secondary clarifier, and a third WAS storage tank. These structures would be the same size and configuration as the existing ones. The previous General Sewer/Facility Plan (2000) planned for additional structures for expansion, and space has been allotted for them. The construction of the third aeration basin will require one new centrifugal blower that is identical to the existing units. Depending on the actual TKN/ammonia loading, a third 540-scfm positive-displacement blower may be required for the third WAS storage tank. To accommodate these blower improvements, the existing blower building will be expanded approximately 20 feet to the south. The southern wall frame of the existing blower building was constructed as an interior frame to allow the blower building expansion as growth occurred in the sewer service areas. This expansion allows for the installation of a new 3,200-scfm blower and 540-scfm positive-displacement blower. As presented in Table 3-4, the projected 2035 peak day flow will be 10.7 mgd. Based on historical plant data from 2011 to 2015, the highest peak hour flow was 9.1 mgd, which was successfully passed through the plant. The WWTP also successfully passed a peak flow of 11.75 mgd during the plant’s 1-year certification completed in 2005. To maintain redundancy requirements and hydraulic capacity, the headworks screening and grit removal will need to be expanded by adding a third influent screen and second grit removal unit. Space has been allotted for these expansions in the original WWTP design. Additionally, a fourth UV disinfection channel will need to be added. Calculations for the recommended alternative using an Excel spreadsheet provided by Ecology are provided in Appendix K. For redundancy, the results of the Excel calculations were also checked against the results of a whole plant process model. 6.5.2.2 Further Improvements Required for Nutrient Removal If further nitrogen removal is desired or required, additional upgrades will be needed. The existing aeration basins were sized and constructed with sufficient capacity so that a swing zone could be added in the future as needed. A baffle wall can be constructed in the first one-third of the aerobic zone to provide a swing zone after the anoxic zone. Submersible mixers would be added to these new swing zones. The swing zone helps improve the operational flexibility in treating influent TKN/ammonia loading. During the summer months, when the influent TKN/ammonia concentrations are high and a higher level of nitrogen removal is required, the swing zone would be operated in anoxic mode to boost denitrification with a high MLR rate to achieve the required effluent total nitrogen (TN). The existing diffusers may be adequate to supply the required air demand in the aerobic zone. This assumption will need to be verified using additional influent ammonia and TKN data. A mixed-liquor recycle rate of 700 percent of the DWMM influent flow would be required to achieve 10 mg/L TN. During the winter, when the influent TKN concentration is low, the swing zone may be operated in aerobic mode to reliably remove ammonia while meeting the TN goal of 10 mg/L. Preliminary design calculations suggest a 100 percent mixed-liquor recycle rate of the WWMM influent flow would be required to achieve the effluent TN level. Detailed design of this process would likely consider a more conservative pump sizing to provide 300 percent of the WWMM influent flow. Process calculations for denitrification are provided in Appendix K. Optimization of the required recycle rate and further evaluation of alternative aeration basin process configurations can be completed as additional influent wastewater data become available. This includes consideration of aeration basin configurations such as the 4-stage Bardenpho. A budgetary project cost for implementing these improvements is approximately $1 million. ` CHAPTER 6 – TREATMENT PLANT EVALUATION 6-22 BI1212191438SEA 6.5.2.3 Design Criteria Table 6-9 presents a summary of the process improvements required to increase plant capacity and design criteria, including the associated dimensions and capacity, for the Phase II improvements described previously. Table 6-9. Summary of Phase II Improvements Design Criteria Component Quantity (new units) Criteria and Sizing Value Mechanical Screen 1 5 MG Vortex Grit Removal System 1 10 MG Grit Pump 1 250 gpm Aeration Basin 1 Volume 0.9 MG Volume Unaerated 14 percent Sidewater Depth 15 feet Length 205 feet Width 39 feet Hydraulic Retention Time (maximum month) 7.5 hours Solids Retention Time (maximum month)a 10 days Mixed-liquor Suspended Solids 2,900 mg/L Minimum Bioreactor Temperatureb 11.5 degrees Celsius Aeration Equipment Multistage Centrifugal Aeration Basin Blower 1 3,200 scfm Fine Bubble Diffusers 459 2.0 scfm each Dissolved Oxygen Concentration 2.0 mg/L Mixed-liquor Recirculation Pumps 1 2,000 gpm each Secondary Clarifier (circular) 1 Diameter 70 feet Sidewater Depth 18 feet Maximum Month Overflow Rate 715 gpd/sf Peak Flow Overflow Rate 1,200 gpd/sf Maximum Month Solids Loading Rate 23.2 lb/sf/d Peak Solids Loading Rate 41.5 lb/sf/d SVI (peak day design) 150 ml/g RAS Ratio 48 percent WAS Tank (each) 1 Volume 0.1 MG Sidewater Depth 20 ft Length 26 ft Width 26 ft CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-23 Table 6-9. Summary of Phase II Improvements Design Criteria Component Quantity (new units) Criteria and Sizing Value WAS Tank Mixers (each) 2 1 7.5 hp maximum Positive-displacement WAS Blower (each) 1 540 scfm Blower Building Expansion 20 ft x 32 ft Ultraviolet Disinfection 1 channel Type Low pressure Design Flow 3.1 mgd TSS 30 mg/L UV Transmittance 65% Aeration Basin Mixers for Swing Zone (each)c 3 10 hp a The selected SRT provides a safety factor of 1.23 for what is required to nitrify the anticipated peak day TKN loading. This SRT correlates with the 10.8 days used for the 2002 design. b Equal to the minimum 7-day average influent temperature from 2008 to 2016. According to 2014 and 2015 data, the maximum week loading is expected to occur in the wet weather season when the influent temperature is low. Process performance at minimum 30-day temperature (12 degrees Celsius) and minimum day temperature (10.7 degrees Celsius) was also evaluated to test sensitivity of the proposed design to wet weather temperature fluctuations. The proposed design was found to provide sufficient capacity to meet process performance requirements during minimum day wet weather temperatures. c Only required if TN less than 10 mg/L is required 6.5.3 Data Needs The following additional data are required for final design of the Phase II Improvements in order to confirm assumptions and design conditions: • Recording of peak hour flow during wet weather conditions • Daily precipitation (inches) during the peak wet weather events 6.5.4 Site Layout Figure 6-4 presents the conceptual layout of the WWTP improvements for both Phase I and Phase II. The layout is intended to show how the various facilities could be located and how much land area would be required. Figure 6-4 also includes the improvements required for additional nitrogen removal. 6.5.5 Flow Diagram Figure 6-5 presents the process flow diagram for the Phase I and Phase II improvements. Appendix K includes the solids mass balance information. 6.5.6 Hydraulic Profile Figures 6-6a and 6-6b present the hydraulic profiles for the Phase I and Phase II improvements for the WWTP. Flow will be conveyed via gravity when the Chehalis River elevation is low. Pumping is required when the Chehalis River elevation is high. Phase I and Phase II improvements would not significantly change the existing hydraulic profile. For Phase II improvements, a conservative MLR rate of 500 percent of the WWMM influent flow was used to develop the hydraulic profile, which is more than anticipated recirculation rate, even if nitrogen removal is required. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-24 BI1212191438SEA 6.5.7 Biosolids Disposal Plan The plant will continue its existing composting operation with the lime stabilization and heat pasteurization process as a backup and supplemental capacity. Combined, both solids stabilization processes have the capacity to handle additional solids through the planning year. 6.5.8 Design Life and Adequacy of Existing Process The new facilities are designed to accommodate flows and loads through the planning year 2035. Primary equipment design life is estimated at 20 years. Structures are based on a 50-year life cycle. The existing plant was built in 2004, and its structures are in good condition with adequate service life remaining through the planning period. The existing process units to be retained are also expected to have adequate service life through the planning period. Mechanical, electrical, and instrumentation components will continue to be maintained and replaced as required per the City’s maintenance program. 6.5.9 Ability to Expand Treatment Plant As previously discussed, the original planning and design of the WWTP included identification of future treatment facilities to be implemented in phases as growth required. The basic framework of the original expansion plan is still relevant and can be revisited for the next round of planning as growth continues. The plant will continue to reserve space for potential future facilities including primary clarification. 6.5.10 Staffing Needs The WWTP currently has 3.5 operator full-time equivalents (FTEs), 1 laboratory technician, 1 pretreatment FTE, 1 farm FTE, 0.5 FTE for maintenance, and 0.5 FTE for instrumentation and electrical. It is anticipated that no additional plant staff are required for the Phase I improvements. Phase II improvements will require 1 additional FTE for increased solids needs and other process requirements. The staffing requirements were verified using the Northeast Guide for Estimating Staffing at Publicly and Privately Owned Wastewater Treatment Plants (NEIWPCC, 2008) as recommended by Ecology. 6.5.11 Future Environment without the Project Phase I improvements are required so that the City can attain full use of the capacity in the aeration basins and secondary clarifiers. Currently, these structures are used for WAS storage. Phase II improvements are required to accommodate growth within the City’s sewer service areas. If expansion is not planned for and considered, a development moratorium could be imposed until upgrades are planned and completed. 6.5.12 Recreation and Open Space A required element of facility plans is a discussion of whether recreation and open space can be incorporated in the alternatives. The City’s WWTP property includes “The Discovery Trail” that follows the bank of the Chehalis River for over 1 mile. The trail was developed through collaboration between the Chehalis River Land Trust and the City’s Utilities Department. Access to the Discovery Trail will not be affected as part of these improvements. 6.6 Water Reclamation and Reuse The 2014 General Sewer Plan Update considered water reclamation and reuse alternatives that the City may implement through future capital and operations projects to address increasingly stringent river discharge criteria for temperature and nutrients. Solutions that were investigated focused on the use of irrigated reuse, groundwater recharge, and constructed wetlands to provide flow diversion and effluent cooling benefits on land surrounding the Centralia WWTP. + , , I I I r: I I I I I I I I I I I I I I I I E2o1DDO I I I 11 I , , , , , , 1, I 1, I I 100 150 I +E200':1900 ++E2009900 + NOTES: 1.EACH CONTRACTOR SHALL BE RESPONSIBLE FOR SAFETY, SECURITY, UTILITY HOOK-UPS AND MAINTENANCE OF THEIR RESPECTIVE STAGING AREA. 2.STAGING AREAS SHALL BE CONSTRUCTED WITH 12 INCHES OF BALLAST, SHOULDER BALLAST, CRUSHED SURFACING OR AGGREGATE FOR GRAVEL BASE OVER SEPARATION GEOTEXTILE. +E2D098DO NO. NORTHING 944 629411.566 946 629424.983 947 630093.248 NOTE: + -$URVEY CONTRdL'IVl'ONUMENT TkBLE EASTING ELEVATION DESCRIPTION 2009797. 608 152.925 PK & Washer Stamped LS 16908 2009182.530 148.380 PK & Washer Stamped LS 16908 2009193.375 149.244 2x2 H&T + + + + + + I ---' ,, -� ii I ii � + �; ,� PHASE I + PHASE II + 3. PROVIDE GRAVEL CONSTR\JCTION ENTRANCES, SILT FENCING AND OTHER _.j._ E!'iQSION CONTROL MEAS�ES AS OUTLINED IN TrlWAPPROVED STORMWATER PdLLUTION PREVENTION PLAN. SEE DRAWINGS SIT-CG-111,SIT-CG-112 AND SIT-CG-1 HORIZONTAL DATUM: PROJECT POTABLE WATER WELL I ii I 11 I 11 CONVEYANCE PIPING ,-l I ' / CONTRACTOR / I X X X X X X X TO GET TO WASHINGTON STATE PLANE COORDINATE SYSTEM, (WASHINGTON SOUTH -4602, AD83/91) SUBTRACT 100,000.000 FEET FROM THE NORTHING AND 1,000,000.000 FEET FROM THE EAST\ G. 4. COMPLETELY REMOVE GRAVEL AND GEOTEXTILE, AND ALL TEMPORARY UTILITIES FROM STAGING AREA AND RESTORE AREA AT THE COMPLETION OF THE PROJECT THEN MULTIPLY EACH BY COMBINED GRID FACTOR 0.9999132480. HORIZONTAL CONTROL SU VEY PERFORMED USING LEICA SR530 GPS UNITS. BASIS FOR CONTROL BEING WSDOT MONUMENTS 272,301, 3 2, 2350, 2351, AND 2514. WAS STORAG +TANKN0.3 + ,---�I I I I I I I +I I I I I coN6RETE RUBBLE I 'BURIED 2' TO 12' BELOW I SURFAeEc-Rt/8BLE-3'cO'� , MAX SIZE MIXED WITH /GRAVEL AND WALKED IN WITH D-8 CAT ANO VIB + /ROLLER I// 6'CHAIN / / LINKFENCE /4�1/ � + X X +E2009600 X X 1-----, I I L ___ _ + VERTICAL !j)ATUM: NAVD 88 • + ELEVATIOl-ls ESTABLISHED FROM \l\(SDOT MONUMENTS 301 i>3,pJl.,&,1D 2514. CONTRql ELEV TIONS ESTABL$EB""" USING A L�eNlll2002 ELECTRONICl;t.EVEL. T X 1--- L __ J X X BLOWER BUILDING EXPANSION + AERATION B41NS WAS STORAGE TANKN0.1 AERATION BAS!NS I N0.3 ! BIOSOLIDS STORAGE FACILITY + X I I I I I I I I + I I I I I X X I+1I + X X X MECHANICAL SCREEN ADD BAFFLE WALLS AND MIXERS TO CREATE SWING ZONE FOR NITROGEN REMOVAL + I I I + I 11 !l I 11 2 I I I I • I I I +''"\'1''"I I I I 11 I 11 I � w� ,------.J------==�-...::::-:._·--- ACCESS GATE + + CONVEYANCE PIPING AND TREATMENT PLANT CONTRACTOR ACCESS + I' I I I I �I t;e I (s I (51 �I I I I I � PHASE II WITH NITROGEN REMOVAL EXISTING + + -------�----_J + + ,.,,,., + r �1,�-r------l-----, r -946 I I I I I I I I I / / (-I I ---\._ 1�/ / ----¥-/ ' \ ,---1 L l i J I I+ I I L ___ J -�-, I I I I � I ! �z � +E200'1000 City of Centralia General Sewer/Facility Plan + + I I 1 CEN Figure 6-4TRALIA WASTEWATER TREATMENT I I I I ' // cl12WL�'�-------------;;;;.;;;;;:/_ _______ -===;;;L�::===::::;;;;;;;;;;;;;;;:;;;;:==;;;;;;;;;;��;;;;2�--/---------_j_--P--LA=--N--T_:U __ P_:G_R:_A.:_D.:.ES.:.._:,S __ 1T-=E-P_LA_N __ j BORDER SIZE IS ANSI D 8:17:30 AM DATE AND TIME PLOTTED: 2017107\25 DESIGN FILE: FP-471111-Fig 6-2.dgn RAW SEWAGE .. ODOROUS AIR 1 TO BIOFIL TER ,------------------------------1 ANOXIC I I HEADWORKS GRIT FUTURE PRIMARY SELECTOR SEPARATOR CLARIFIERS (DEFERRED PORTABLE I SAMPLER TO PHASE 2) I��� �----1 1 T ----1� i--a-----IT � -.----.---1""--� I ----� I AERATION BASINS ADD BAFFLE AND MIXERS TO CREATE A SWING ZONE FOR NITROGEN REMOVAL IF REQUIRED WAS PUMPING SECONDARY CLARI FIERS ULTRAVIOLET LIGHT DISINFECTION POST AERATION MECH�NICAL SCREEN NOTE 11. SCREENINGS D I ----�------------< 2 >-----------FLOW SP IT/ WEIR.TY J OUTFALL TO CHEHALIS RIVER t f-0 ........ _ I I I I I I I DUMPSTER 0 FLOW STREAM IDENTIFICATION NUMBER 0 SAMPLE LOCATION � MAGNETIC FLOW METER 0 PUMP PHASE I PHASE II - - --PHASE II WITH NITROGEN REMOVAL EXISTING GRIT TO DISPOSAL DUMPSTER GRIT SEPARATOR 1. EXISTING MANUAL BAR SCREEN NOT SHOWN FOR CLARITY. FUTURE PRIMARY SLUDGE TO GRIT SEPARATOR AND SOLIDS HANDLING DRY AND LIQUID RAS RAS IWAS STORAGE _JTANKS L SECONDARY SLUDGE TO SOLIDS HANDLING ODOROUS AIR TO BIOFIL TER LIME STORAGE SILO ,--! ________ _ �1it1R PRESS I I -7 I I ODOROUS AIR TO BIOFIL TER SECONDARY SCUMP PUMPS WET AIR SCRUBBER ODOROUS AIR TO BIOFIL TER RAS PUMPING COMPOST FACILITY EFFLUENT PUMP STATION {\ LAND Ll ----APPLICATIONPOLYMER �--� SYSTEM 0 l ��loER I I I ODOROUS I AIR PLANT WATER p•)-------BELT WASHWATER PUMP LIME r 7 SCREW I CONVEYOR I I BIOSOLIDS STORAGE FACILITY �5�i�Jrr sFER THERMOBLENDEr ��� : * SLUDGE TRANSFER PASTEURIZATION r'---� I �--� I 0 CONVEYOR 2 -------L _____ VESSE':__ __ L _ 1 _J PRODUCT C I LJ ....JI '---� 1 TRANSFER Go oo o I �-� 1 ____ CONVEYO� _____ _J ���x��i1NT �------------����=�- City of Centralia General Sewer/Facility Plan '-.I.- Figure 6-5 CENTRALIA WASTEWATER TREATMENT PLANT PROCESS FLOW DIAGRAM \Jrl2AK�---------------------------------- BORDER SIZE IS ANSI D 8:16:30 AM DATE AND TIME PLOTTED: 20 7107\25 DESIGN FILE: 'P-47' 11 10 -�:Jn1111-Fig 5-2,dgn ELEVAT ION (FT) ELEVAT ION (FT 175----------------------------------------------------------------------------------------------------------------------175 167.02 165.98 . 165.86 165.30 ... 1162.647 ---. -� . 160.85 . -. 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ALL ELEVAT IONS 1988 NAVD. 2. HEADLOSS REQUIREMENT FOR FUTURE PRIMARY CLARI FIERS HAS BEEN INCLUDED IN HYDRAULIC PROFILE. 3. PLANT RECYCLE FLOWS ADDED DOWNSTREAM OF INFLUENT SAMPLER AT HEADWORKS. 4. WE IR GATE DOWNSTREAM OF CONSTANT LEVEL GATE W ILL MODULATE BETWEEN 152.5 AND 152.75 FOR Q<1.2 MGD AND IS.SET TO 149.00 FOR Q>1.2 MGD. ·--------· .1..CHEHALIS . RIVER CITY OF CENTRALIA GENERAL SEWER/ FACILITY PLAN Figure 6-6a HYDRAULIC PROFILE FOR THE CENTRALIA VWVTP PHASE I IMPROVEMENTS geng019d_672413-1.dgn 28-JUL-2017 9:22 AM ELEV ATION (FT) ELEV ATION (FT 175----------------------------------------------------------------------------------------------------------------175 166.86 165.82 . 165.76 164.99 · · ·1162.457 · · · · ·�· 160.92 · · ·[J][IQJ · · · · · · · · · · 157.76 157.66 · · · · · · · · · · · ·�· · · · �T1suiff · · · · 148.60 ...... ·. ·.��·. ·.. . ... ·. ·. ·. ·. ·. ·. ·. ·. ·. ·. ...... ·.ill7-a-W. ·. ·. ·. ·. ·. ·. . .... ·. ·. ·. ·. ·. ·. ·. ·. . .. ·. ·. ·. ·. ·. ·. ·. ·. · .... ·.l-12�·. · . . ·. ·. ·. ·. ·. ·. ·. · .. �� ... ·. ·. ·. ·. ·. · .. ·. ·. ·. . . . . . . . . . . . . . . ........... . 170-------------'""_-..;.._-.;...=+-;..;.-..;..-.;...;..;. ...... -__ · .·+-·-··_--__ · -----------------------+--·-·· _--L. n,-J. -·t ·_-_-_-_------+----··...,--�/ _______________ r __ o_.w _ _-_f6-·9_.:o _ _-o_· .-_._. ________ · -------------------------+-----t---+--· _--_-_-_---+-----·----+--+·--_--_-_-_-_-_· -----+-· -_-_-_-_-----·-+-----·--_-_--_-_-_-_-_· +--+---· +--_-_-_-_----+·----+------+------· _--_-_-_-_--_-_· _____ ·_-_-_--_-_-_-_-_· --170 BYP ASS .-----t-------t-----t-----1------."-______ TOP .OE FUTURE. ________ ........ _ . _ . ________ . . _______ . wE1R::f 67:�� � �lt===·:;,:· z:::. ;::: :=:=:L:-:-: :-:-:-/:-fr:!:,: 1�fc:=·�=: :_:_· _· _· ·+-·�· �· ---, :::,�� . --: w,u_ ,,,,,., :_\ ••••• ·�· . . . . . •. . • . • • • • • • . . . 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ALL ELEV ATIONS 1988 NAVO. 2. HE ADL OSS REQUIREMENT FOR FUTURE PRIM ARY CL ARI FIERS H AS BE EN INCL UDED IN HYD RAULIC PROFIL E.3. PL ANT RECYCLE FLOWS ADDE D DOWNSTRE AM OF INFLUENT S AMPLER AT HE ADWORKS. 4. WEIR GATE DOWNSTRE AM OF CONST ANT L EVEL GATE WILL MODUL ATE BETWE EN 152.5 AND 152.75 FOR Q<1.2 MGD AND IS_SETTO 149.00 FOR Q>1.2 MGD. .CHE HALIS . RIVER CITY OF CENTRALIA GENERAL SEWER/ FACILITY PLAN Figure 6-6b HYDRAULIC PROFILE FOR THE CENTRALIA VWVTP PHASE II IMPROVEMENTS geng019d_672413-2.dgn 28-JUL-2017 9:44 AM CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-33 Due to the changing weather patterns and recent drought, impacts to the City’s water supply initiated an investigation of potential long-term options to manage the City’s water resources. This investigation built on the previous work and focused on resource recovery options, especially in the event that river discharge becomes infeasible. Options considered the following evaluation criteria: • Available potential locations • Practicality of the alternative • Facility needs (or capital costs) • Annual maintenance costs • Regulatory requirements • Effectiveness of the alternative at reducing the development of potable resources • Managing WWTP effluent characteristics Based on the evaluation, three alternatives stood out as the most desirable: aquifer storage and recovery (ASR), constructed wetland, and a combination of ASR and seasonal irrigation. Table 6-10 compares these three options further by identifying capital costs, applicable permits, potential data needs for implementation, and the relation to drivers for reclaimed water use. Table 6-10. Evaluation of Top Alternatives Alternative Class 5 Estimated Costa Permits Data Needs Relation to Drivers Water Quality Offset Potable Demands ASR $1,145,000 to $2,455,000 • Reclaimed Water Permit • State Wastewater Discharge Permit • Well logs • Soil investigation • Hydrogeologic study • Water chemistry report • Class A • Indirectly Constructed Wetlands $1,960,000 to $4,203,000 • Reclaimed Water Permit • NPDES Permit • Soil investigation • Hydrogeologic study • Floodway investigation/site survey • Preferred type of wetland • Class A • Indirectly ASR and Seasonal Irrigation $1,590,000 to $3,405,000 • Reclaimed Water Permit • State Wastewater Discharge Permit • NPDES Permit • Soil investigation • Hydrogeologic study • Water balance • Evapotranspiration rates • Crop options • Class A • Directly, depending on the season a Class 5 cost estimate includes a -30% to +50% accuracy range (CH2M, 2013). It is important to note that the estimated costs do not include construction and O&M to produce Class A effluent. Depending on current State regulations for the effluent characteristics at the time of implementation, one of the following options can be used for additional treatment: advanced UV oxidation or reverse osmosis. Further investigations and data collection are needed to determine the best alternative for the City should reclaimed water become a necessary solution. The City will continue to track water demands (along with developments in reclaiming and reusing wastewater for municipal water supply) and will consider pursuing reuse at the appropriate time, including preparation of a plan that meets the requirements of Chapter 90.46 WAC. CHAPTER 6 – TREATMENT PLANT EVALUATION 6-34 BI1212191438SEA 6.7 Other Potential Improvements Plant staff identified other improvements they wish to implement, which are described in the following subsections. 6.7.1.1 Ultraviolet Channel Gates The existing Westech floating gates on the UV channel are prone to leakage, which initiates plant alarms. The City tested a finger weir in place of the gate on one channel to provide level control while avoiding nuisance alarms. The test was successful, and the City plans to replace all the gates with steel finger weirs as a permanent solution. This would be implemented as part of the City’s plant maintenance program and is not included in the capital improvement projects presented in Chapter 8. 6.7.1.2 Solids Handling Upgrades (C.I.P. WW-2) Three projects are included in C.I.P. WW-2 and include dewatered sludge conveyance, belt filter press and compost facility covers. The following describes each of the projects in more detail. (i) Dewatered Sludge Conveyance (C.I.P. WW-2, part a) Modifications to the solids handling facility for dewatered sludge conveyance were first described in and approved as part of the 2011 Facility Plan Amendment (CH2M, 2011). WAS is dewatered to 12 to 16 percent total solids using an existing 2-meter BFP in the solids handling facility. Polymer is added to the WAS to coagulate the solids to assist in dewatering. A conveyor belt transports dewatered WAS to a Serpentix conveyor, which feeds the lime pasteurization system. For composting, the dewatered WAS is run through the RDP Technologies equipment without lime addition, so it can be loaded into a truck and taken to the biosolids storage facility for composting. Modifications to the existing solids handling facility are necessary to transport dewatered WAS to the composting facility without operating the RDP lime pasteurization equipment. Dewatered WAS will be conveyed to a new progressing cavity pump using the existing conveyor belt. The Serpentix conveyor will be removed and a new pump located in its place, so the conveyor belt discharges to the new pump’s feed hopper. The pump will be able to discharge either to the RDP system or the truck loading area by use of valves and piping on the discharge of the pump. Figures 6-7 and 6-8 show plan and section views of the proposed modifications. The pump will be equipped with a receiving hopper and inlet screw conveyor to allow handling of the dewatered WAS. The hopper will be located directly beneath the conveyor belt discharge, so there will likely be a higher surface in the middle of the hopper than the edge. The pump will have a VFD and will operate based on the level in the hopper. An ultrasonic level sensor will be placed in the hopper with an aiming style mount to sense the level at the outer edge of the hopper where the dewatered WAS level is likely lowest. A proportional control will be used to adjust the pump speed to maintain hopper level. A pressure switch would be installed immediately downstream of the pump to automatically stop the progressing cavity pump in the event of low or high pressure. Low pressure indicates the pump is running dry, which will damage the pump. High pressure indicates that the discharge pipeline is blocked. Dewatered WAS will be pumped through a 6-inch-diameter, glass-lined, ductile iron pipe either to a dump truck in the existing biosolids load-out area for transport to the composting facility or to the inlet of the thermoblender at the beginning of the lime pasteurization process. A tee and two plug valves downstream of the pump discharge will allow plant staff to control where the WAS is pumped. ...\FPA_4-1A_406250.dgn 11/4/2010 7:18:13 AM City of Centralia General Sewer/Facility Plan Figure 6-7 PLAN VIEW OF PROPOSED MODIFICATIONS ...\FPA_4-1B_406250.dgn 11/4/2010 7:46:11 AM City of CentraliaGeneral Sewer/Facility Plan Figure 6-8 SECTION VIEW OF PROPOSED MODIFICATIONS CHAPTER 6 – TREATMENT PLANT EVALUATION BI1212191438SEA 6-39 (b) Belt Filter Press (C.I.P. WW-2, part b) The City currently has one BFP and, though not required, would like to add a second 2-meter press as a standby unit to increase operational flexibility and better accommodate unforeseen equipment downtime. As discussed in Section 6.4, the existing BFP has enough capacity to handle existing solids production and dewater a few times each week. A second BFP would provide the City with a backup unit, as well as helping to maintain operational flexibility with future growth. (c) Compost Facility Improvements (C.I.P. WW-2, part c) While the composting piles are under cover in the biosolids storage building, the green waste used as amendment in the compost operations are outside the building and covered by tarps to protect them from the rain. These tarps tend to break down from UV exposure after 1 year and need to be replaced frequently. The City is considering investing in a manufactured compost cover system that is waterproof but does not trap moisture to cover the amendment piles instead. Additionally, since the compost facility design capacity is short of the capacity needed once maximum month plant flows surpass 5.5 mgd, the City is considering adding concrete or wooden bay walls between compost piles, to allow for taller piles and to use more space between piles. This would increase facility capacity by at least 10 percent and allow the City to continue using the composting facility without the need to use the lime stabilization process for supplemental capacity for a few more years. 6.7.1.3 Programmable Logic Controller and Motor Control Center Upgrades (C.I.P. WW-4) The WWTP recently experienced a failure of one of the solids system adjustable-frequency drive (AFD) units. While addressing this failure, it was discovered that the AFD units at the WWTP are no longer supported by the manufacturer and that installation of a new AFD would not be supported by the current control system. The control system PLCs were also discontinued by the manufacturer as of March 2011. Upgrading AFD units and PLC controller modules is recognized as a significant upgrade to the facility with the objective of maintaining stable operations. Additionally, the existing DeviceNet communication between the PLCs and the equipment in the MCCs should be replaced. Migrating away from DeviceNet to Ethernet will increase the maintainability of the equipment. Starting in 2017, the City has been working to implement required improvements to the MCCs and PLCs. CHAPTER 7 BI1212191438SEA 7-1 Operations and Maintenance This section presents descriptions of the various routines and programs needed to operate and maintain the City's WWTP and sewer system. The City Wastewater Department provides the resources and staff to perform system repairs, implementation of the standard operating procedures, and ongoing system maintenance. Future projects or equipment replacement recommendations to improve the operation and minimize the maintenance of the system are provided in the last section of this chapter. 7.1 Staffing The City currently employs the equivalent of 13 full-time equivalent (FTE) positions to oversee the O&M of the collection system and WWTP. Table 7-1 presents a breakdown of the type and amount of staff allocated to various positions within the City’s Wastewater Department. Some positions represent less than one FTE position, because of shared duties among other positions and City Departments. Table 7-1. Wastewater Department Operations and Maintenance Staff Position FTE Wastewater Treatment Plant Manager 0.5 Operators 3.5 Maintenance 0.5 Instrumentation and Electrical 0.5 Laboratory 1.0 Pretreatment 1.0 Farm 1.0 Total WWTP 8.0 FTE Collection System Manager 0.5 Instrumentation and Electrical 0.5 Technicians 4 Total Collection System 5.0 FTE 7.2 Scheduled Operations and Maintenance Activities 7.2.1 Wastewater Treatment Plant The plant is staffed 5 days per week, 8 hours per day, by the plant manager, a process analyst, a lead operator, three operators, and a half-time I&E technician on a Monday through Friday, 8-hour shift. An on-call person staffs the plant for 2 to 3 hours per day on the weekends and holidays. Additionally, the collection system and WWTP require staff to be on call for afterhours emergencies and unscheduled O&M needs. Plant operations activities include continual process control, laboratory analysis, and CHAPTER 7 – OPERATIONS AND MAINTENANCE 7-2 BI1212191438SEA regulatory reporting. Maintenance activities include lubrication, cleaning, equipment maintenance, replacement, and repairs. 7.2.2 Collection System Collection system staff are responsible for the O&M of the collection system sewer mains and pump stations. The City has adopted a regularly scheduled maintenance program for the pump stations. Additionally, a few problem areas within the collection system require ongoing maintenance. Grinder Pumps The City has approximately 39 grinder pumps installed throughout the City. The City has developed a service agreement with the owners of these systems, which states that operations and maintenance of these systems is the responsibility of the owner and that a qualified individual or firm is performing proper maintenance. The City’s Municipal Code Title 15.10.180 Paragraph H outlines the use of alternative systems which covers the installation, ownership and maintenance of the systems. The City is planning to add a list of approved qualified contractors that can perform maintenance on these systems in the near future. All maintenance and inspections scheduled will be tracked and maintained by the City of Centralia maintenance program. Appendix L contains the service agreement example between the City and sewer customer. Sewer Cleaning Staff members have identified areas that tend to have recurring requirements for sewer cleaning, and these areas have been set up in the City’s management system to generate timely work orders (annually, quarterly, or weekly) depending on the severity. Typically, the problem areas are those where grease buildup occurs. On average, a crew spends approximately 5 days per month flushing the lines. Root Control Certain areas of the sewer system routinely experience problems root intrusion. Root intrusion is a chronic problem at numerous points in the system. Approximately twice per year, staff must trim and remove roots from inside the affected sewer lines to prevent blockages. Manhole Lid Replacement and Adjustment The City routinely replaces up to 10 manhole frames and lids per year. The manhole frame and lid replacement program allows the City to replace broken manholes, replace unsealed manholes, and adjust manholes as needed to match existing road grades. This program is also used to directly address inflow into the City’s collection system. 7.2.3 Pump Station The City’s 25 pump stations are inspected once per week. During the weekly check, the wet well and control panel are inspected, the volume of grease in the wet well is noted, and the pumps and valves are exercised. At a minimum, the pump station wet wells are cleaned monthly. Equipment amperage draw is measured every month for predictive maintenance on the mechanical equipment. All pump stations have radio telemetry and are monitored continuously for alarms. For 2 days each year, the crew will check the alarms triggered from the pump stations as they are received at the WWTP. The four largest pump stations are equipped with permanent standby power and are tested weekly. The generators are equipped with timers to allow them to be exercised weekly. The generators are serviced annually and are load-tested during that time. The remaining pump stations are powered by one portable unit when necessary, which is tested quarterly. Staff also maintain the grounds around pump stations on an as-needed basis. CHAPTER 7 – OPERATIONS AND MAINTENANCE BI1212191438SEA 7-3 7.3 Programs 7.3.1 Sewer Service The City has a sewer ordinance (Centralia Municipal Code 15.10) that describes domestic and high strength users, user charges, side sewer connections, damage to sewers, permit application, type, and fees, sewer construction and testing, prohibited discharges, violations and penalties, and schedule of charges. A copy of this ordinance is included in Appendix L. 7.3.2 Fats, Oil, and Grease The City has a fats, oil, and grease (FOG) program including mandatory FOG pretreatment per the Centralia Municipal Code 15.10.280. One staff member is dedicated to the operation of this program, which requires that any customers serving or preparing food where grease may be introduced into the system shall have pretreatment facilities to prevent discharge of FOG. At a minimum, the grease interceptors must meet the specifications of the current Uniform Plumbing Code, and the dischargers must maintain the grease interceptors in a manner that will prevent FOG from being carried into the system. Grease traps and interceptors are required to be regularly cleaned and maintained by the customer, such that the total volume of captured grease and settled solid material never displaces more than 25 percent of the total volume of the unit. The cleaning frequency shall be at least once per week, unless an alternate schedule is approved by the City. Maintenance logs are required and must be presented to the City during inspections. Part of the FOG program includes customer education, including spending time with each new customer explaining the purpose for a FOG program, providing materials documenting options to the customer, and providing equipment alternatives. As a result, customers may be more responsive to installing and maintaining the required systems. In addition, the City imposes a fine for City-sponsored cleanings and re-inspection of systems that have not been properly maintained. 7.3.3 Water Surface Elevation Monitoring This program consists of measuring water surface elevations at strategic manholes within the existing collection system to evaluate the wet weather system flows. Centralia staff began this monitoring program in October 1998 and are continuing to gather data. The initial findings were summarized in the previous General Sewer Plan, and more recent work is summarized in Section 5.2.2. This program is used to identify the extent of surcharging in the system and the variation in surcharging during the year. For each measurement, the manhole lid is removed, and the water surface elevation in relation to the pipe crown is observed and recorded. If the pipe is flowing more than full, the distance between the water surface elevation and the manhole rim is recorded. A data sheet template is presented in Appendix M. Two staff are required for each measurement: one person to control traffic; and the other to remove the manhole lid, take measurements, record the observations, and replace the manhole lid. Measurements are taken routinely at each identified manhole once per month from May through October and weekly from November through April. This frequency was identified because the wet season WWTP flow can fluctuate widely over the course of a single week, while the WWTP flow is relatively stable during dry periods. Each trunk is measured over a 5-year period to develop a relationship with Chehalis River flow. River flow data is recorded on the same day that pipe and manhole levels are measured to develop the correlation between the two items. Three groundwater monitoring wells were installed in the 1990s in downtown Centralia. The data from these monitoring wells are used to monitor groundwater elevation and its linkage, if any, to sewer surcharging. CHAPTER 7 – OPERATIONS AND MAINTENANCE 7-4 BI1212191438SEA 7.3.4 Flow Monitoring The City’s flow monitoring program is another approach to evaluating wet weather flow. This program consists of monitoring dry and wet weather flow at select locations and recording and evaluating flows at existing pump stations. Flow monitoring is used to quantify the impact of I/I reduction projects. Positive results in the form of measurable differences between the ratio of dry weather to wet weather flows can serve to validate the City's I/I reduction program and provide justification for future pipeline replacement projects. The City currently has four flow monitors to measure flows in the collection system. In the absence of additional flow monitoring devices, pump station run records are used as surrogates to quantify flows. This information can be used to support the development of a hydraulic model of the sewer system. 7.4 Unscheduled Maintenance Activities Approximately twice per month, the City will get calls from customers complaining of a backed-up sewer. Staff will perform a customer courtesy check by investigating whether the blockage is occurring on the customer's property or out in the street. If the blockage is within the City's portion of the system, efforts are taken to clear the sewer immediately. Staff also respond to odor complaints by determining the source of odors and flushing the line as required to remove the odiferous conditions. This approach appears to be adequate to date. A crew is sent out to perform repairs on collection lines and force mains as breakages occur. Typically, a line break will occur during construction of non-sewer projects in the area, and spot repairs are required. Staff perform sewer permit connection inspections on an as-requested basis. Typically, the majority of inspections are requested during the summer. 7.5 Management System and Recordkeeping The City currently uses Rockwell’s FactoryTalk View supervisory control and data acquisition (SCADA) system for the WWTP and collections system. The SCADA system controls WWTP operations and Collections lift/pump station monitoring. The historian software (Pi) records flow data and process control data and is used to generate the monthly NPDES permit’s required DMR. Data are stored on a server. The WWTP and Collections department use additional software, a computerized maintenance management system, to record maintenance activities and generate work orders. 7.6 Improvements There are several items or programs that can be added to the City's Wastewater Department to support improvement of the entire sewer system. The following subsections present each potential improvement. 7.6.1 Equipment To better maintain and operate the system, the City recently purchased a new sewer jet truck and a CCTV truck. In addition, the following equipment items have been identified as required by staff: • WAS storage tank (discussed in Chapter 6) • MLSS recirculation pumps/piping (discussed in Chapter 6) • Vactor truck, purchased in 2003 and scheduled for replacement in 2018 • Service truck with crane, purchased in 2003 and scheduled for replacement in 2018 • Duty truck, half-ton, purchased in 2006 and scheduled for replacement in 2020 CHAPTER 7 – OPERATIONS AND MAINTENANCE BI1212191438SEA 7-5 • John Deere backhoe, purchased in 2002 and scheduled for replacement in 2020 • Lead Coll tech truck, Chevy Colorado, purchased in 2006 and scheduled for replacement in 2020 7.6.2 Flow Monitoring The City recognizes that high rates of infiltration are a critical concern for its sewer system; however, there is limited data to substantiate the variation of I/I in the sewer system. High river elevations and a corresponding high groundwater table are believed to be the cause of the City's excessive infiltration occurrences. The collection system contains approximately 41 miles of clay pipeline, 19 miles of concrete pipeline, and 3 miles of asbestos cement pipeline (installed over 80 years ago). These are the areas suspected of having the highest amounts of I/I. The City has conducted extensive I/I reduction efforts at various times within the past 40 years in an attempt to reduce infiltration into the sewer system. The efforts undertaken between 1977 and 1980 had no noticeable effect. The City replaced approximately 22 percent of its collection system between 1990 and 1996. Based on measurements taken downstream at the WWTP, no significant reduction in I/I was measured as a result of these programs. However, recent efforts to remove I/I, such as slip lining the interceptor that crosses China Creek, have been successful. There was a noticeable decrease in influent flow to the plant corresponding with completion of the slip lining project. To demonstrate to Ecology that the City is committed to working on the I/I problem, the City has dedicated $540,000 per year for I/I demonstration, reduction and removal projects. The I/I reduction program described in Chapter 5 proposes a methodology for flow monitoring that both establishes whether I/I reduction is effective and provides information necessary to determine whether adequate capacity exists for future flows. As discussed in Chapter 5, the existing sewer system analysis was based on peak sanitary flows, not peak wet weather flows, because of the absence of data. Prior to connecting new services, it is recommended that the City verify existing wet weather flows in the trunk sewers to determine what additional capacity is present within the existing collection system. The water surface elevation monitoring approach is a minimal program designed to use the fewest resources to collect data that can be used to verify the pipe flow assumptions made in the Chapter 5 analysis and quantify the impact of I/I on system capacity. The City has a limited number of flow monitors that can be deployed to quantify existing collection system flows. The City is researching new flow monitors to increase the number of useable flow monitors and is also pilot testing the use of SmartCovers that can monitor and record level data in a manhole. The City currently has three SmartCovers in use and is considering installing additional SmartCovers. As more resources become available, a more comprehensive flow monitoring program can be implemented to better characterize the system and form the basis for the development of a hydraulic model. The most critical issue is to determine the extent and impact of surcharging in the existing system, which could limit future system connections. The data from the monitoring program will be used to determine the ability of the existing system to accept additional flows, as discussed in Chapter 9. 7.6.3 Television Inspection and Cleaning As noted previously, the City cleans sewers on an as-needed basis. To be more proactive in maintaining the sewer system and identifying problem areas, the City is implementing a comprehensive CCTV inspection and sewer cleaning program. In general, the program is conducted during the four summer months when flows are the lowest. It is possible to clean approximately 5,000 feet of pipe per day using a truck-mounted sewer jet. By inspecting the cleaned line with a CCTV camera, problems within the sewer line can potentially be identified before they become critical. The program has been developed with the goal of cleaning and inspecting the entire system over a 5-year cycle. The priority should be to clean and inspect the main trunk sewers first to determine their CHAPTER 7 – OPERATIONS AND MAINTENANCE 7-6 BI1212191438SEA condition. The other sewers should then be inspected in order of those most likely to be impacted by future development. A proposed schedule by area is as follows: 1. Downtown 2. Fords Prairie 3. Waunch Prairie 4. Cooks Hill 5. South Centralia 7.6.4 Smoke Testing The City does not currently perform regular smoke testing. Smoke testing is a useful tool to identify building sewers, grinder pumps, and under-house plumbing that are a source of I/I. It can also demonstrate to property owners the need for required corrections. Periodic smoke testing throughout the service area would assist the City in identifying sources of I/I, especially inflow, and working with property owners to reduce or eliminate these problems. 7.6.5 Staffing The Phase II improvements will require 1 additional FTE to handle additional solids and process requirements. Additionally, for the collection system, implementation of an expanded flow monitoring program and routine comprehensive sewer cleaning would be beneficial to the City. Depending on the magnitude of the programs, up to two additional staff could be required to implement the proposed programs. CHAPTER 8 BI1212191438SEA 8-1 Financial This chapter presents the financial analysis for the capital improvement projects identified in this plan, including estimated capital costs, O&M costs, and life-cycle costs. Project financing and user charges required to support the projects are also discussed. 8.1 Costs Class 5 capital cost estimates were prepared to the Association for the Advancement of Cost Engineering International standards for the projects identified in the plan. As defined by these standards, the expected accuracy range for a Class 5 estimate is a low of minus 30 percent and a high of plus 50 percent. 8.1.1 Capital Table 8-1 summarizes the capital projects identified in this sewer system evaluation and estimated cost. Table 8-1. Proposed Sewer and Facility Plan Capital Projects ID Project Description Total Estimated Cost (2016 dollars) CC-1 China Creek Interceptor Stabilization Install riprap along Chehalis River to protect pipelines from erosion $1,750,000 CS-1 Centralia Station New sewer to serve Centralia Station development $3,880,000 M-1 Pump Station Maintenance Replacement of mechanical and electrical and concrete corrosion coatings $1,820,000 II-1 I/I Demonstration and Removal Projects Demonstrate technology, determine effectiveness and confirm costs of I/I removal technologies $2,700,000 WW-1 Phase 1 WWTP Improvements Design and construction of recirculation pumps and solids storage $5,840,000 WW-2 Solids Handling Upgrades Upgrade dewatered sludge conveyance, new belt filter press, and compost facility covers $1,630,000 WW-3 Headworks Screen Additional headworks screen $2,120,000 WW-4 PLC and MCC Upgrades Upgrade PLC and MCC equipment $500,000 WW-5 Phase 2 WWTP Improvements Design and construction of additional plant capacity $17,202,000 WW-6 Temperature Compliance Evaluation Update Evaluate and select temperature mitigation alternative $60,000 WW-7 Thermal Mitigation Needs Design and construct thermal mitigation alternative $1,240,000 ES-1 Pipeline Replacement Program Aging pipeline replacement program $5,220,000 ES-4 First Street Between G and F Streets Existing System Improvement $160,000 F-1 Ford’s Prairie Interceptor Provide sewer to UGA $11,810,000 F-2 Area North of and Adjacent to Kuper Road Provide sewer to UGA $2,950,000 F-3 Private Drives Area Provide sewer to UGA $1,310,000 CHAPTER 8 – FINANCIAL 8-2 BI1212191438SEA Table 8-1. Proposed Sewer and Facility Plan Capital Projects ID Project Description Total Estimated Cost (2016 dollars) F-4 Trailer Park Area Provide sewer to UGA $1,270,000 F-5 Southeast Area Provide sewer to UGA $7,920,000 F-6 Industrial Area Provide sewer to UGA $1,040,000 F-7 Reynolds Avenue Area Provide sewer to UGA $2,540,000 F-9 Southwest Area Provide sewer to UGA $4,030,000 F-10 Gallagher Road Area Provide sewer to UGA $1,950,000 NS-7 Fords Prairie Residential Provide sewer to UGA $8,200,000 US-7 Fords Prairie Provide sewer to unsewered area within City limits $1,090,000 CH-1 Cook’s Hill Sewer Extension Provide sewer to UGA $14,520,000 CH-2 Cook’s Hill Pump Stations Provide sewer to UGA $1,030,000 NS-5 Cooks Hill Residential Provide sewer to UGA $7,450,000 NS-15 Graf Road Residential Provide sewer to UGA $4,660,000 US-2 South Cooks Hill Residential Provide sewer to unsewered area within City limits $80,000 NS-9 Kresky Residential I Commercial Provide sewer to UGA $2,120,000 US-3 East of Plummer Lake Provide sewer to unsewered area within City limits $670,000 W-1 Waunch Prairie Interceptor Provide sewer to UGA $3,310,000 W-2 North Pearl Street Interceptor Provide sewer to UGA $4,310,000 W-5 Dixon Road and Roanoke Street Area Provide sewer to UGA $1,990,000 W-6 Southeast Area Provide sewer to UGA $2,270,000 W-7 Oakview Avenue Area Provide sewer to UGA $2,130,000 W-8 Carson Street Area Provide sewer to UGA $6,030,000 W-9 Sawall and Lowery Area Provide sewer to UGA $3,140,000 WH-1 Widgeon Hill Sewer Extension Provide sewer to UGA $3,900,000 WH-2 Widgeon Hill Pump Station Provide sewer to UGA $1,040,000 US-4 Ham H/11 Provide sewer to unsewered area within City limits $9,660,000 NS-10 South Ham Hill Residential Provide sewer to UGA $3,000,000 Total $159,542,000 Table 8-2 (which is located at the end of Section 8.1) summarizes proposed system improvements for implementation over the next 6 years (2019 through 2024) based on the analysis described in Chapters 5 and 6 and the review of sewer projects necessary for improvement of the collection system. CHAPTER 8 – FINANCIAL BI1212191438SEA 8-3 It is also recommended that the City begin implementation of the Ford’s Prairie interceptor by constructing the first two segments before 2020. The Ford’s Prairie interceptor provides several benefits to the City: • Allows for future growth in an area located outside the flood plain • Diverts flow away from the China Creek pump station, thus providing capacity without the need to expand the China Creek pump station and interceptor • Eliminates several pump stations and maximizes gravity sewers, thereby minimizing long-term maintenance costs • Provides an opportunity to remove flow from the Downtown Trunk 1 by diverting flows from Waunch Prairie/Davis Hill It is important for the City to begin constructing this interceptor in advance of WSDOT’s improvements to Harrison Avenue and to coordinate completion with improvements to Harrison Avenue. 8.1.2 Life Cycle Table 8-3 presents the estimated total capital, annual O&M, and life cycle costs based on the conceptual design for the Phase 1 and 2 WWTP improvements. These costs are in 2016 dollars and have been rounded. Life-cycle costs were developed from the total capital (project) costs, annual O&M costs, and replacement costs for a 50-year project life. Annual O&M costs included labor for operations and routine maintenance, materials, and electricity. Equipment replacement was based on a 20-year mechanical equipment life. The following are assumptions used in the analysis: • Initial year of operations: 2018 for Phase 1 and 2027 for Phase 2 • Life-cycle cost analysis period: 50-year operation • Year of analysis for present worth computations: 2016 • Inflation Rate: 3.0 percent • Discount rate: 5.0 percent 8.2 User Charges The two main revenue sources for the wastewater department consist of revenues from the monthly base rate and a usage charge. All residential sewer customers pay a monthly minimum plus an amount that is the lesser of (1) a charge for units of water used that month or (2) the "Winter Cap", which is the average monthly charge for water used in the months December through March. The Winter Cap is reset each April. Commercial customers have no cap feature. The 2016 rates are shown in Table 8-2. Table 8-2. Monthly Sewer Rates, 2016 Charge Single- Family Residential Low-Income Senior/Totally Disabled Multiple- Family Residential Domestic-Strength Commercial/ Industrial High-Strength Commercial/ Industrial Inside City Limits Monthly Base Rate $63.82 $57.41 N/A $24.17 To be determined on a case-by-case basis Usage per unit of watera $2.25 $2.25 $2.21 $12.87 To be determined on a case-by-case basis First Dwelling — — $62.48 — — Each Additional — — $55.68 — — CHAPTER 8 – FINANCIAL 8-4 BI1212191438SEA Table 8-2. Monthly Sewer Rates, 2016 Charge Single-Family Residential Low-Income Senior/Totally Disabled Multiple-Family Residential Domestic-Strength Commercial/Industrial High-Strength Commercial/Industrial Monthly Minimum — — — $81.17 — Outside City Limits Monthly Base Rate $95.75 $86.10 — $36.26 To be determined on a case-by-case basis Usage per unit of watera $3.39 $3.39 $3.30 $19.33 To be determined on a case-by-case basis First Dwelling — — $93.72 — — Each Additional — — $83.53 — — Monthly Minimum — — — $121.76 — a Unit of water equals 100 cubic feet 8.3 Funding Sources A number of funding sources might be available to the City for financing the City-sponsored projects presented in Table 8-3. Potential funding sources are described in this section. The existing system improvements were prioritized by the City based on the perceived need for the improvement to be completed prior to projects with fewer deficiencies or less risk of damage due to failure of the system. Priority and schedule for developer funded projects is dependent on the timing and specific needs of the developer and the industrial facilities. For planning purposes, a general schedule has been established for the developer funded projects; however, the estimated schedule will need to be modified as residential and commercial development occurs. Future projects that are not identified as part of the City’s C.I.P may become necessary. Such projects may be required in order to remedy an emergency situation or to address unforeseen problems. Due to budgetary constraints, the completion of such projects may require modifications to the recommended C.I.P. The City retains the flexibility to reschedule, expand or reduce the projects included in the CIP and to add new projects to the C.I.P when new information becomes available for review and analysis. 8.3.1 Conventional Revenue Bond Financing Conventional revenue bond financing assumes the City would issue debt in the tax-exempt bond market through an investment banking firm for the capital needs of the C.I.P. Revenue bonds are secured by the rate revenues of the utility. The interest rate is dependent on the market and the bond rating of the City. CHAPTER 8 – FINANCIAL BI1212191438SEA 8-5 Table 8-3. Proposed System Improvements (2016 Dollars) Project Description Year and Estimated Cost Total Estimated Costa 2019 2020 2021 2022 2023 2024 CC-1 - China Creek Interceptor Stabilization Install riprap along Chehalis River to protect pipelines from erosion $107,000 $162,000 $1,481,000 $1,750,000 M -1 - Pump Station Maintenance Replacement of mechanical and electrical and concrete corrosion coatings $560,000 $560,000 $560,000 $140,000 $1,820,000 II-1 - I/I Demonstration & Removal Projects Demonstrate technology, determine effectiveness and confirm costs of I/I removal technologies $540,000 $540,000 $540,000 $540,000 $540,000 $2,700,000 WW-1 - Phase 1 WWTP Improvements Design and construction of recirculation pumps and solids storage $800,000 $5,040,000 $5,840,000 WW-4 - PLC and MCC Upgrades Upgrade PLC and MCC equipment $100,000 $100,000 $100,000 Total $900,000 $6,347,000 $1,362,000 $2,581,000 $680,000 $550,000 $9,970,000 a All costs are in 2016 dollars and are Class 5 estimates with an expected range of accuracy of -30% to +50%. b Total project cost is shown. It is assumed that the cost will be shared by the Port of Centralia and the City. CHAPTER 8 – FINANCIAL 8-6 BI1212191438SEA Table 8-4 presents the Phase I and Phase II WWTP improvements capital, annual O&M costs and total life cycle costs. Table 8-4. Wastewater Treatment Plant Improvements Costs (2016 dollars) Item Phase I WWTP Improvements Phase II WWTP Improvements Capital Cost $5,840,000 $10,910,000 Annual O&M Cost $29,000 $147,000 Total Life-Cycle Cost $5,869,000 $13,540,000 8.3.2 Double-barreled Revenue Bonds Double-barreled revenue bond financing assumes that the City will issue debt in the governmental tax-exempt bond market though an investment banking firm in the amount of the capital needs. Double-barreled revenue bonds are secured by City taxes but are repaid by the utility's rate revenues. The interest rate is dependent on the market and the bond rating of the City and may be 25 to 50 basis points lower than a conventional revenue bond. Bond coverage is typically not required and is assumed to be zero. 8.3.3 Centennial Clean Water Fund - Design and Construction The Centennial Clean Water Fund is a state grant/loan program that finances water pollution control facilities and activities. Eligible projects include planning, design, acquisition, construction, and improvement of water pollution control facilities and activities. Facilities planning and design are eligible for loans, and facilities construction is eligible for grants and loans. The interest rate for a 15- to 20-year term is 75 percent of the market rate. 8.3.4 State Revolving Fund for Water Pollution Control The State Revolving Fund (SRF) for Water Pollution Control is a loan program to fund high-priority projects to protect water quality. Eligible projects include wastewater treatment facilities, nonpoint source pollution projects, and estuary protection and preservation programs for Puget Sound and the lower Columbia River region. Loans are available for planning, design, and construction up to 100 percent of total eligible project costs. Ceiling amounts are dependent on total funds available. 8.3.5 Public Works Trust Fund Construction Program The Public Works Trust Fund Construction Program is a revolving loan fund that provides low-interest loans to eligible local governments in Washington State to finance the construction phase of infrastructure projects. The interest rate may be 1 to 3 percent with local matches of 10 to 30 percent, respectively. The loan term would be a maximum of 20 years or the life of the project. Eligible projects must improve public health and safety, respond to environmental issues, promote economic development, or upgrade system performance. In addition, only sanitary sewer projects that are not eligible for the SRF loan program are eligible for public works board construction loans. The Legislature changed the Construction Loan eligibility criteria when it passed the 2015-2017 Biennial Capital Budget. 8.3.6 Alternate Funding Projects not financed by the City include those that may be funded partially through various private sources, primarily using developer financing. Another financing possibility for certain types of projects is the formation of special assessment districts, such as local improvement districts, wherein the benefited properties would be assessed the cost of system improvement based on benefits received. CHAPTER 8 – FINANCIAL BI1212191438SEA 8-7 8.4 Capital Financing Plan Financing for the City’s wastewater capital program consists primarily of proceeds from long-term, fixed-rate sewer revenue bond sales; short-term variable rate borrowing; cash transfers from the operating fund; and low-interest loan programs administered by the State of Washington, such as State Water Pollution Control Revolving Loan Fund loans and Public Works Trust Fund loans. Ongoing system O&M programs (including pump station maintenance and I/I removal) is paid from the wastewater O&M budget and is funded by rates. Projects driven by development, such as the Centralia Station, are assumed to be paid for by the developer. The City contracted with FCS Group to complete a rate and sufficiency analysis including the wastewater system. Due to the Centennial Grant and the ongoing strong fiscal and operational performance of the utility, the analysis determined that no rate adjustments are needed above the previously-adopted inflationary rate adjustment policy of 2.00 percent annually. It recommended that the City revisit the study findings during the budget cycle to check that the assumptions used remain appropriate and no significant changes have occurred that would alter the results of the study. The City should use the study findings as a living document, continuously comparing the study outcomes to actual revenues and expenses. Any significant or unexpected changes will require adjustments to the rate strategy proposed. The City annually reviews the proposed sewer system improvements to prioritize funds and plan financing for capital projects. Annual wastewater budgets, including capital expenditures, are then reviewed and approved each year by the City Council. The FCS Group analysis also identified the Phase II WWTP Improvements as a significant item for future study. The anticipated timing of this project is outside the capital cost horizon used in the rate study. As such, detailed design and construction costs estimates are not yet available, and the rate revenue requirements for this project are not reflected in the financial modeling. Potential project funding sources include the State Centennial Grant program, the Clean Water State Revolving Fund loan program, wastewater revenue bonds, Capital Facility Charge revenues, and general wastewater rate revenues. FCS Group recommended that once a construction date and project cost estimates are known, an update to the wastewater rate study be conducted. Completing this planning effort at least three years prior to the project will maximize the City’s ability to mitigate the rate impacts of the project, as well as position the City to achieve the best outcomes for project funding. CHAPTER 9 BI1212191438SEA 9-1 Implementation This chapter describes the implementation of improvements described in this General Sewer/Facility Plan, including the following: • Plan adoption • Water quality management plant conformance • Environmental checklist and permits • Public involvement process • Developer extensions • Construction standards 9.1 Plan Adoption A key element of implementing the General Sewer/Facility Plan is proper compliance with state and local requirements governing adoption of such documents. The plan should be reviewed by City staff and then submitted to Ecology for review. An electronic version of the plan should also be made available on the City’s website. Following receipt of comments from affected agencies and completion of the final environmental determination, the plan will be adopted by the City Council. The final environmental determination and Ecology approval will serve as additional support and endorsement of the Plan and the recommended improvements contained in the document. 9.2 Water Quality Management Plan There is no formal water quality management plan in place for the Chehalis River near the City. As previously discussed in Chapter 2, TMDLs for temperature, DO, and fecal coliform are being implemented by Ecology through the City’s NPDES discharge permit. In particular, the loading allocations in the City’s NPDES permit are part of the TMDL for DO. WWTP effluent is expected to continue to meet or exceed current effluent quality and meet the plant’s NPDES discharge permit obligations as discussed in Chapter 6. 9.3 State Environmental Policy Act Compliance with SEPA is a prerequisite for obtaining any permits and approvals for a WWTP project. SEPA allows agencies to both consider and mitigate for environmental impacts of proposals as well as to provide opportunities for public participation prior to any final decision. SEPA Environmental Checklists were developed for both the Phase I WWTP Modifications project and the non-project review of the plan. The City, as the SEPA lead agency, has conducted SEPA review for the Phase I project and will conduct the non-project review for the plan prior to finalizing the plan. No comments were received during the comment period for the Phase 1 WWTP Modifications SEPA checklist, which ended on November 3, 2017, and the City issued a Determination of Non-Significance for the project on October 10, 2017 and for the plan on March 2, 2019. The SEPA Environmental Checklists and documentation can be found in Appendix N. 9.4 State Environmental Review Process All projects that apply for financial assistance from the SRF for facility planning or construction must meet the provisions of the State Environmental Review Process (SERP; WAC 173-98-720). SERP compliance helps to ensure that environmentally sound and cost-effective alternatives are selected and CHAPTER 9 – IMPLEMENTATION 9-2 BI1212191438SEA that the public has had an opportunity to learn about and comment on the potential environmental impacts of a proposal. SERP documentation for the Phase I WWTP Modifications project is included in Appendix N. All projects that apply for financial assistance from the SRF for construction must comply with the federal cross cutting authorities (cross-cutters). These include several federal laws, executive orders, and government-wide policies that apply their own terms to projects and activities receiving federal financial assistance, regardless of whether the statute authorizing the assistance makes them applicable. Appendix O summarizes how the Phase I WWTP Modifications project will comply with the cross- cutters. 9.5 Schedule Table 8-3 shows the planned system improvement projects for the next 6 years. The design of Phase I WWTP improvements would be completed in 2017 with construction and improvements operational in 2020. If growth continues as projected, Phase II WWTP improvements would be required by approximately 2024. If the City chooses to apply for SRF monies to help fund the Phase II improvements, application for design funding would be completed in 2020, design would be completed in 2021, and construction would be completed in 2022 to 2023. 9.6 List of Required Permits The following is a preliminary list of anticipated permits and approvals for the Phase I and II WWTP improvements project: • State Environmental Review Process Compliance, Washington State Department of Ecology • Notice of Construction, Washington State Department of Ecology • State Environmental Policy Act Documentation and Determination, City of Centralia • Building Permit, Lewis County • Grading Permit, Lewis County • Electrical permits, Department of Labor and Industries • Plumbing permits, Department of Health • NPDES general construction permit, Washington State Department of Ecology 9.7 Public Involvement Process The draft General Sewer/Facility Plan was made available to the public through the City’s website. 9.8 Developer Extensions Private funding is a frequently used mechanism for financing construction of sewer system improvements in the City. Historically, system improvements have been required as a condition of approval of any proposed development project. A primary implementation goal of the City is to be able to respond to developer requests for sewer connections. To date, the City is not able to determine the available capacity in its system and the requirements for additional connections. The analysis presented in Chapter 5 gives the City an indication of those lines, which appear to be approaching capacity during existing peak sanitary dry weather flows. In addition, the amount of surcharge that might be expected from the identified additional flows was also estimated. This information, combined with the flow monitoring program, will give the City the tools to better estimate the capability of the existing trunks to accept additional flows. CHAPTER 9 – IMPLEMENTATION BI1212191438SEA 9-3 The ability for the City to make this estimation will improve over time as data is collected and the preliminary assessments in this plan are refined. Three options for a level of effort of data collection are (1) no action, use only existing information, (2) visually inspect water surface elevations in manholes, and (3) detailed flow monitoring analysis. If additional connections are made, the risk to the City includes the potential for sewer backups or overflows. Sewer backups into residences or businesses are highly undesirable and could result in citizen complaints or legal action or both. The level of effort expended in data collection affects the amount of certainty with which the City can add future hookups. The City can use data collected from monitoring water surface elevations to confirm the estimations in this plan. The level of surcharging present (if any) can be used as an indicator of the remaining capacity of each main trunk sewer. The projected flows from the proposed new hookups can be used to calculate the additional headloss, which could occur in the trunk sewer. This, combined with the documented level of surcharging in the trunk sewer, can be balanced against the potential for overflows and/ or sewer backups and can be used as a basis for determining whether the additional flows should be accepted. The pump station records can be used to quantify how much capacity remains in the appropriate pump station and to determine if it is sufficient for the new flows. Much of this analysis can be conducted by City staff using a basic hydraulics analysis program. The least risky approach is to perform the detailed flow monitoring analysis. The flow monitoring analysis data could be used to quantify the flows in the existing system under surcharged and non- surcharged conditions and to predict the flow characteristics of new hookups. The flow information could be used to develop a hydraulic model, which predicts the hydraulic grade line through the system with existing and future flows. This can indicate whether potential exists for sewer backups or overflows, or both, related to the addition of the new flows. Another implementation goal of the City is to minimize the number of pump stations in the system by requiring a comprehensive approach to laying out new systems that employ deeper sewer lines laid at minimum slopes, which could eventually feed into the existing system via gravity. In the past, most developments that applied for sewer service developed a sewer system that meets the development's immediate needs. Often this took the form of a shallow collection system and pump station to connect to the existing system. In the short-term, developers could be allowed to install pump stations; however, the ultimate plan would be to convert them to a gravity system. This requires the developers to plan ahead and submit a two-phase development approach to the City, demonstrating the compliance of the development's sewer service with the City's vision. The City’s Municipal Code Title 15.10.180 Paragraph H outlines the use of alternative systems which covers the installation, ownership and maintenance of the systems. The City is planning to add a list of approved qualified contractors that can perform maintenance on these temporary systems. All maintenance and inspections scheduled will be tracked and maintained by the City of Centralia maintenance program. Specific items must be required of new pump stations to permit the area served by the pump station to be connected via gravity sewer in the future. The wet well bottom depth must be low enough so that it could discharge to the existing system via a gravity line at 0.4 percent slope in the future. Lines that discharge to the pump station must be laid out such that they could also discharge directly to the nearest trunk sewer at 0.4 percent slope. An exception to these requirements may be granted if the potential pump station is in a low area, which precludes connecting with the gravity system. 9.9 Construction Standards Contract documents for all projects constructed within the City shall be prepared based on the most current edition of the City of Centralia Design and Development Guidelines. These guidelines are the same as the standards in Ecology's Criteria for Sewage Works Design (Ecology, 2019). CHAPTER 10 BI1212191438SEA 10-1 References Executive Summary City of Centralia. 2007. Centralia Comprehensive Plan. Accessed February 28, 2018. http://www.cityofcentralia.com/Page.asp?NavID=396. Adopted fall of 2007. Metcalf & Eddy, Inc. (Metcalf & Eddy). 2014. Wastewater Engineering, Treatment and Reuse. Fifth Edition. Washington State Department of Ecology (Ecology). 2019. Criteria for Sewage Works Design (Orange Book). Publication 98-37. August. Accessed February 28, 2018. https://fortress.wa.gov/ecy/publications/summarypages/9837.html. Water Environment Research Foundation. 2003. Methods for Wastewater Characterization in Activated Sludge Modeling. Chapter 1 Lewis County. 2013a. Comprehensive Land Use Plan for Lewis County, Washington (Lewis County Plan). Updated November 25, 2013. Accessed February 28, 2018. http://lewiscountywa.gov/communitydevelopment/comprehensive-plan. Lewis County. 2013b. Countywide Planning Policies for Lewis County. Adopted December 16, 2013. Accessed February 28, 2018. http://lewiscountywa.gov/attachment/7682/CWPPAdopted16Dec2013.stan.pdf. Washington State. 2018. Washington Administrative Code. Accessed February 28, 2018. http://apps.leg.wa.gov/wac/. Chapter 2 City of Centralia. 1998. Shoreline Master Plan. June. City of Centralia. 2017. Centralia Comprehensive Plan. Adopted summer of 2017. Accessed February 28, 2018. http://www.cityofcentralia.com/Page.asp?NavID=396. CH2M HILL Engineers, Inc. (CH2M). 2000a. Wastewater Treatment Plant Final Environmental Impact Statement. December. HDR Engineering Inc. 2013. City of Centralia Water System Plan. April. Accessed February 28, 2018. http://www.cityofcentralia.com/Page.asp?NavID=773. Lewis County. 2013a. Comprehensive Land Use Plan for Lewis County, Washington (Lewis County Plan). http://lewiscountywa.gov/communitydevelopment/comprehensive-plan. Updated November 25, 2013. Lewis County. 2013b. Countywide Planning Policies for Lewis County. http://lewiscountywa.gov/attachment/3158/MicrosoftWordCWPP.may13.2010w.phil2.pdf. Adopted December 16, 2013. National Oceanic and Atmospheric Administration (NOAA). 2016. U.S. Climate Data. National Centers for Environmental Information. Accessed February 28, 2018. http://www.ncdc.noaa.gov/. Washington Department of Natural Resources. No Date. Geologic Map of Southwest Washington. CHAPTER 10 – REFERENCES 10-2 BI1212191438SEA Chapter 3 CH2M HILL Engineers, Inc. (CH2M). 2000b. Wastewater Treatment Plant Facilities Plan. Prepared for the City of Centralia. February. City of Centralia. 2009. Design and Development Guidelines (Guidelines). February. http://www.cityofcentralia.com/Page.asp?NavID=861. U.S. Environmental Protection Agency (EPA). 1985. Infiltration/Inflow, I/I Analysis and Project Certification. May 1985. Washington State Building Code Council. 2012. Uniform Plumbing Code. Washington State Building Code. Chapters 51-56 WAC. July. Accessed February 28, 2018. https://fortress.wa.gov/ga/apps/SBCC/File.ashx?cid=2663. Washington State Department of Ecology (Ecology). 2019. Criteria for Sewage Works Design (Orange Book). Publication 98-37. August. Accessed February 28, 2018. https://fortress.wa.gov/ecy/publications/summarypages/9837.html. Washington State Department of Transportation and the American Public Works Association (WSDOT and APWA). 2008. 2008 Standard Specifications for Road, Bridge, and Municipal Construction. Accessed February 28, 2018. https://www.wsdot.wa.gov/publications/manuals/fulltext/M41-10/SS2008.pdf. Chapter 4 None Chapter 5 City of Centralia. 2017. Centralia Comprehensive Plan. Adopted summer of 2017. Accessed February 28, 2018. http://www.cityofcentralia.com/Page.asp?NavID=396. Washington State Department of Ecology (Ecology). 2019. Criteria for Sewage Works Design (Orange Book). Publication 98-37. August. Accessed February 28, 2018. https://fortress.wa.gov/ecy/publications/summarypages/9837.html. U.S. Environmental Protection Agency (EPA). 1991. Alternative Wastewater Collection Systems. U.S. Environmental Protection Agency (EPA). 2010. State of Technology for Rehabilitation of Wastewater Collection Systems Report. EPA/600/R-10/078. Chapter 6 CH2M HILL Engineers, Inc. (CH2M). 2000c. City of Centralia Utilities Department Wastewater Treatment Plant Facilities Plan. January. CH2M HILL Engineers, Inc. (CH2M). 2011. Facility Plan Amendment for the City of Centralia Wastewater Treatment Plant Composting Facility. CH2M HILL Engineers, Inc. (CH2M). 2017. City of Centralia WWTP – Phase I Improvements Design. October 3. Jenkins D., M. Richard, and G. Daigger (Jenkins et al.). 2003. Manual on the Causes and Control of Activated Sludge Bulking, Foaming, and Other Solids Separation Problems, 3rd edition. IWA Publishing. Metcalf & Eddy, Inc. (Metcalf & Eddy). 2014. Wastewater Engineering, Treatment and Reuse. Fifth Edition. New England Interstate Water Pollution Control Commission (NEIWPCC). 2008. The Northeast Staffing Guide for Estimating Staffing and Privately and Publicly Owned Wastewater Treatment Plants. CHAPTER 10 – REFERENCES BI1212191438SEA 10-3 Washington State Department of Ecology (Ecology). 2019. Criteria for Sewage Works Design (Orange Book). Publication 98-37. August. Accessed February 28, 2018. https://fortress.wa.gov/ecy/publications/summarypages/9837.html. Water Environment Research Foundation. 2003. Methods for Wastewater Characterization in Activated Sludge Modeling. Washington State Department of Ecology (Ecology). 2016. Water Quality Standards for Surface Waters of the State of Washington, Chapter 173-201A WAC, Publication Number 06-10-091. Adopted August 1, 2016. Revised October 2017. Chapter 7 None Chapter 8 None Chapter 9 City of Centralia. Various dates. Design and Development Guidelines. http://www.cityofcentralia.com/Page.asp?NavID=30. Washington State Department of Ecology (Ecology). 2008. Criteria for Sewage Works Design (Orange Book). Publication 98-37. August. Accessed February 28, 2018. https://fortress.wa.gov/ecy/publications/summarypages/9837.html. Appendix A City of Centralia General Sewer/ Facility Plan Crosswalk WT0621161107SEA A‐1 APPENDIX A City of Centralia General Sewer/Facility Plan Crosswalk TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS I. General Information A. Site Description X Chapter 2 B. Location Map X Chapter 2 C. Present and Proposed Sewer Service Area X X Chapter 2 D. Problem Identification; Purpose and Need for Proposed Plan X X Chapter 1 E. Description of Discharge Standards including NPDES Permit requirements X Chapter 6 F. Remove Legacy Information X Completed II. Background Information A. Existing Environment 1. Water X Chapter 2 2. Air X Chapter 2 3. Floodplains X Chapter 2 4. Shorelands X Chapter 2 5. Wetlands X Chapter 2 6. Prime or unique farmland X Chapter 2 7. Archaeological and historical sites X Chapter 2 APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK A‐2 WT0621161107SEA TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS 8. Wild and scenic rivers X Chapter 2 9. Endangered and threatened species/habitats X Chapter 2 10. Public health X Chapter 2 B. Demography and Land Use 1. Current population X Chapter 2 2. Current land use zoning X Chapter 2 3. Current land use map X Chapter 2 4. Population trends and methods used to determine those trends X Chapter 2 5. Design Growth Rate analysis X Chapter 2 C. Layout Maps 1. Boundary lines of municipality and vicinity X Chapter 2 2. Existing and proposed sewers and areas served X Chapter 4, Chapter 5 3. Existing and proposed pump stations and force mains X Chapter 4, Chapter 5 4. Topography and elevations of existing and proposed ground X Chapter 2 5. Information on streams, lakes, other bodies of water, and discharges. X Chapter 2 6. Information on water systems X Chapter 2 D. Existing Wastewater Facilities 1. Information on existing wastewater facilities in the area. X Chapter 4 2. Describe current treatment process X Chapter 4 a. Discussion on the provisions for treatment, discharge, and reuse. X Chapter 4 b. Existing design capacity & wastewater flows and characteristics X Chapter 4 APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK WT0621161107SEA A‐3 TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS 3. Current plant loading (tables of at least 1 year of data) X Chapter 3 4. Locations & waste characteristics of current industrial dischargers. X X Chapter 3 5. Sources of plant loadings a. Industrial X Chapter 3 b. Commercial X Chapter 3 c. Domestic X Chapter 3 d. Infiltration X Chapter 3 e. Inflow X Chapter 3 6. Seasonal and diurnal load and flow variations X Chapter 3 7. Flow meter accuracy checked X Flow meter accuracy has been checked 8. Lab analysis checked for accuracy by state certified lab X Lab analysis has been checked 9. Plant bypasses X Chapter 4 10. Sewer System Design Criteria X Chapter 3 E. Receiving Water Evaluations 1. Summary of existing water quality data X Chapter 6 – Reasonable Potential Analysis 2. AWT need evaluated X Chapter 6 – Reasonable Potential Analysis 3. Impairment Analysis X Chapter 6 – Reasonable Potential Analysis a. Water quality analyzed to comply with Antidegradation provisions of WAC 173‐201A‐300 to 330 X Chapter 6 – Reasonable Potential Analysis b. Mixing zone analysis X Not applicable. Permit‐defined dilution factors used in Impairment Analysis. c. Toxics in effluent X Chapter 6 – Reasonable Potential Analysis APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK A‐4 WT0621161107SEA TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS d. Nutrient, bacteria, and chemical impacts X Chapter 4, Chapter 6 – Reasonable Potential Analysis e. Measurable change in water quality standards being at the boundary of the chronic mixing zone (if allowed) X Chapter 6 – Reasonable Potential Analysis f. Receiving water flows X Not applicable. Permit‐defined dilution factors used in Impairment Analysis. g. Metals Limits X Chapter 6 – Reasonable Potential Analysis h. Temperature X Chapter 6 – Reasonable Potential Analysis F. I/I Discussion X X Chapter 3 1. Degree in collection system X Chapter 3 a. Methods used and data adequate to support excessive or non‐excessive I/I determination X Chapter 3 b. Non‐excessive I/I determined and used as part of base flow in design X X Chapter 3 c. Schedule for sewer rehab including where rehabilitation is proposed and amount of correction from rehabilitation is realistic X X Chapter 5 2. Sewer overflows X Chapter 4 a. Fixes recommended X Chapter 4 includes improvements made 3. Combined sewer overflows X Not applicable; no combined sewer overflows G. Sanitary surveys for unsewered Communities X Chapter 2 H. Information on existing wells or other water supply sources X Chapter 2 I. Detailed Plant Capacity Analysis X Chapter 6 III. Future Conditions A. Demography or Land Use Chapter 2 APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK WT0621161107SEA A‐5 TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS 1. Population projections based on appropriate data source X Chapter 2 2. Future land use changes/zoning densities X Chapter 2 3. Reserved capacity X Capacity has not been reserved for any specific developers. 4. Recreation and open space alternatives including access to bodies of water X Chapter 6 B. Waste Load X Chapter 3 1. Future flows & loadings X Chapter 3 a. Domestic X Chapter 3 b. Commercial X Chapter 3 c. Industrial X Chapter 3 d. I/I X Chapter 3 2. Industrial wastes requiring special handling? X None IV. Alternatives A. Locations 1. Alternative sites X Not applicable; all treatment alternatives located within existing plant site 2. Proximity of residences or developed areas X Not applicable; all treatment alternatives located within existing plant site 3. Topography and flood potential for 25‐year and 100‐year flood X Not applicable; all treatment alternatives located within existing plant site 3. Impacts to existing wetlands including mapping of existing wetlands X Not applicable; all treatment alternatives located within existing plant site APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK A‐6 WT0621161107SEA TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS 4. Adequacy of site soils to support the facility X Not applicable; all treatment alternatives located within existing plant site B. Design Criteria 1. Design population X Chapter 2 2. Design flow conditions (peak, average, wet, & dry weather) X Chapter 3 3. BOD, TSS, nutrients X Chapter 3 4. Recycle streams X Chapter 3 5. Special handling for industrial wastes X Not applicable a. Treatability in STP X Not applicable b. Pretreatment needs X Not applicable C. Collection System Alternatives X Chapter 5 D. Types of Systems Evaluated (i.e., all practicable waste treatment technologies) X Chapter 6 1. Fixed growth X Not selected for further evaluation; did not want to change existing plant suspended growth process 2. Suspended growth X Chapter 6 3. Land treatment X Not selected for further evaluation; did not want to change existing plant suspended growth process 4. Lagoons X Not selected for further evaluation; did not want to change existing plant suspended growth process 5. Operational improvements and use of existing facilities X Chapter 6 6. Innovative or alternative X Chapter 4 APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK WT0621161107SEA A‐7 TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS 7. No action X Not selected for further evaluation; action is required to provide adequate treatment capacity for future growth 8. Provide for nutrient removal X Chapter 6 E. Residual Solids Management Plan X Chapter 4 1. Evaluation of expected solids quantities and quality X Chapter 6 2. Potential disposal or beneficial use options (including regional biosolids disposal and utilization options) X Chapter 6 F. Evaluation and Effects of Flow Reduction Measures X Chapter 3 and Chapter 5 G. Evaluate & Rank Alternatives X X Chapter 6 1. Criteria Chapter 6 a. Total capital costs X Chapter 6 b. Environmental impacts X Chapter 6 c. Public acceptability X Chapter 6 d. Meet effluent limits X Chapter 6 e. Ease of maintenance X Chapter 6 f. Present worth (including O & M) X Chapter 6 H. Select Final Alternatives to Further Evaluate and Rank Chapter 6 1. Evaluate and rank final alternatives X Chapter 6 2. Select recommended alternative X X Chapter 6 V. Final Recommended/Selected Alternatives A. Site Layout including proposed sampling locations X Chapter 6 APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK A‐8 WT0621161107SEA TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS B. Flow Diagram X Chapter 6 C. Hydraulic Profiles (peak plant flow and high receiving water flow or elevation and low plant flow conditions) X Chapter 6 D. Solids Mass Balance X Chapter 6 E. Follows Recommendations in Criteria Manual X Yes F. Design Criteria for Each Process Unit X X Chapter 6 G. Sizing Calculations for Each Process Unit X Chapter 6, appendix H. Design Life X Chapter 6 I. Age and Adequacy of Existing Process X Chapter 6 J. Environmental Impacts X Chapter 9 K. Recycle Flow Accounted for? X Yes, design calculations in appendix L. Site Specific Outfall Analysis X Chapter 6 – Reasonable Potential Analysis M. Biosolids Disposal Plan X Chapter 6 N. Ability to Expand Treatment Plant X Chapter 6 O. Growth expectations X Chapter 2 1. Population X Chapter 2 2. Commercial X Chapter 2 3. Industrial X Chapter 2 P. Ability to Expand Collection System X Chapter 5 Q. Future Environment Without the Project X Chapter 6 R. Implementation APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK WT0621161107SEA A‐9 TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS 1. O&M Staffing Requirements X Chapter 9 2. Lab Staffing Requirements X Chapter 9 3. Feasibility of Implementation X Chapter 9 6. Schedule Chapter 9 VI. Financial A. Capital, O&M, Costs of Selected Alternative X Chapter 8 B. User Charges for Selected Alternative With Loan & Without Loan X X Chapter 8 C. Existing and Proposed Cost per Service X X Chapter 8 D. Funding of Project X X Chapter 8 1. Possible funding sources identified X Chapter 8 2. Effects of possible funding sources on project and user costs evaluated X Chapter 8 E. Capital Financing Plan X Chapter 8 VII. Other Requirements A. WQMP Conformance X X Chapter 9 B. SEPA Compliance Achieved X X Chapter 9 C. NEPA compliance X X Chapter 9 D. SERP compliance X Chapter 9 E. Environmental Issues Analysis X Chapter 9 F. Projects identified in a: 1. General sewer plan X Current Plan 2. Capital improvement plan X Chapter 8 APPENDIX A CITY OF CENTRALIA GENERAL SEWER/FACILITY PLAN CROSSWALK A‐10 WT0621161107SEA TOPIC Washington State Department of Ecology Facility Plan Washington State Department of Ecology General Sewer Plan Attachment 1 to Centralia General Sewer Plan Approval, dated July 28, 2015 SECTION IN REPORT/COMMENTS G. Public participation X Chapter 9 H. List of Needed Permit Approvals for Recommended Alternative X Chapter 9 I. Discussion of who will own, operate, and maintain the system X Chapter 7 Appendix B Water System Facility Map UT UT UT UT [Ú [Ú [Ú [Ú [Ú [Ú #### ## # # # "b"b §¨¦5 S em i n a r y H i l l D r Little Hanaford Rd Harrison AveSkookumchuck River Reynolds Ave Chehalis Rive r Galvin Rd Cooks Hill Rd Ham Hill RdSa l z e r V a l l e y R dPearl StPearl StTower AveMain S t Seminary Hill Reservoir Gleason BPS Seminary BPS Ham Hill Reservoir Ham Hill BPS N. Tower Well Downing Road Well Zenkner Valley BPS Davis Hill BPS Davis Hill Reservoir K Street Well Washington Street Well Riverside Well Fords Prairie Wells and Treatment Facility Eshom Road Well Tennis Court Wells Borst Park Wells Cooks Hill BPS Cooks Hill Reservoir Locust S t Walnut S t Pear S t Cherr y S tAsh StKing St1st St 3rd St 5th St 6th St Central BlvdOxford AveMarion St Nick RdRussel Rd Eshom RdTilly Av eJoppish RdRiver Heights Rd Scammon Creek RdBlanchard Rd Roanoke St ¯0 5,000 10,0002,500 Feet Figure 5-1 Water System Facility Map April 2013 CITY OF CENTRALIA WATER SYSTEM PLAN Legend [Ú Pump Station UT Reservoir #Inactive Well #Active Well "b PRV Waterline Diameter (in) <4 4 6 8 10 12 16 18 Water Body Road Centralia City Limits Centralia Urban Growth Boundary City of Centralia Retail Service Area City of Chehalis Water Service Area Appendix C Industrial User Permits and Lewis County Interlocal Agreement Page 1 of 35 Permit No. ST 6139 Issuance Date: February 24, 2015 Effective Date: July 1, 2015 Expiration Date: June 30, 2020 STATE WASTE DISCHARGE PERMIT NUMBER ST 6139 State of Washington DEPARTMENT OF ECOLOGY Southwest Regional Office P.O. Box 47775 Olympia, WA 98504-7775 In compliance with the provisions of the State of Washington Water Pollution Control Law Chapter 90.48 Revised Code of Washington, as amended, Lewis County Community Development Department P.O. Box 180 Centralia, WA 98531 is authorized to discharge wastewater in accordance with the special and general conditions which follow. Facility Location: 1411 South Tower Avenue Centralia, WA 98531 SIC Code: 4212 NAICS Code:562111 Industry Type: Solid Waste Transfer Station POTW Receiving Discharge: The City of Centralia Minor Industrial User Richard Doenges Southwest Region Manager Water Quality Program Washington State Department of Ecology Page 2 of 35 Permit No. ST 6139 TABLE OF CONTENTS SUMMARY OF PERMIT REPORT SUBMITTALS ............................................................................. 4 SPECIAL CONDITIONS .......................................................................................................................... 5 S1. DISCHARGE LIMITS .................................................................................................................... 5 S2. MONITORING REQUIREMENTS ................................................................................................ 5 A. Monitoring Requirements ................................................................................................... 5 B. Sampling and Analytical Procedures .................................................................................. 7 C. Flow Measurement, Field Measurement, and Continuous Monitoring Devices ................ 7 D. Laboratory Accreditation .................................................................................................... 8 E. Request for Reduction in Monitoring ................................................................................. 8 S3. REPORTING AND RECORDING REQUIREMENTS ................................................................. 8 A. Discharge Monitoring Reports ............................................................................................ 8 B. Permit Submittals and Schedules ...................................................................................... 10 C. Records Retention ............................................................................................................. 10 D. Recording of Results ......................................................................................................... 10 E. Additional Monitoring by the Permittee ........................................................................... 10 F. Reporting Permit Violations ............................................................................................. 11 G. Other Reporting ................................................................................................................ 12 H. Maintaining a Copy of this Permit .................................................................................... 13 I. Dangerous Waste Discharge Notification ......................................................................... 13 J. Spill Notification ............................................................................................................... 13 S4. OPERATION AND MAINTENANCE ......................................................................................... 13 A. Bypass Procedures ............................................................................................................ 13 S5. PROHIBITED DISCHARGES ...................................................................................................... 15 A. General Prohibitions ......................................................................................................... 15 B. Specific Prohibitions ......................................................................................................... 16 C. Prohibited Unless Approved ............................................................................................. 16 S6. DILUTION PROHIBITED ............................................................................................................ 16 S7. APPLICATION FOR PERMIT RENEWAL OR MODIFICATION FOR FACILITY CHANGES........................................................................................................................ 17 S8. NON-ROUTINE AND UNANTICIPATED DISCHARGES ....................................................... 17 S9. SPILL CONTROL PLAN.............................................................................................................. 17 A. Spill Control Plan Submittals and Requirements .............................................................. 17 B. Spill Control Plan Components ........................................................................................ 18 S10. SLUG DISCHARGE CONTROL PLAN ...................................................................................... 18 GENERAL CONDITIONS ...................................................................................................................... 20 G1. SIGNATORY REQUIREMENTS ................................................................................................. 20 G2. RIGHT OF ENTRY ....................................................................................................................... 20 G3. PERMIT ACTIONS....................................................................................................................... 21 G4. REPORTING A CAUSE FOR MODIFICATION ........................................................................ 21 G5. PLAN REVIEW REQUIRED ....................................................................................................... 21 Page 3 of 35 Permit No. ST 6139 G6. COMPLIANCE WITH OTHER LAWS AND STATUTES ......................................................... 21 G7. TRANSFER OF THIS PERMIT ................................................................................................... 21 G8. REDUCED PRODUCTION FOR COMPLIANCE ...................................................................... 22 G9. REMOVED SUBSTANCES ......................................................................................................... 22 G10. PAYMENT OF FEES .................................................................................................................... 22 G11. PENALTIES FOR VIOLATING PERMIT CONDITIONS.......................................................... 22 G12. DUTY TO PROVIDE INFORMATION ....................................................................................... 22 G13. DUTY TO COMPLY .................................................................................................................... 22 APPENDIX A ............................................................................................................................................ 23 Page 4 of 35 Permit No. ST 6139 SUMMARY OF PERMIT REPORT SUBMITTALS Refer to the Special and General Conditions of this permit for additional submittal requirements. Permit Section Submittal Frequency First Submittal Date S3.A. Discharge Monitoring Report (DMR) Monthly August 15, 2015 S3.A. DMR - Priority Pollutant Data - Single Sample Data 2/permit cycle February 1, 2016 & January 2, 2019 S3.F. Reporting Permit Violations As necessary S4.B. Reporting Bypasses As necessary S7. Application for Permit Renewal 1/permit cycle January 2, 2019 S9. Spill Plan 1/permit cycle February 1, 2016 S10. Slug Discharge Control Plan 1/permit cycle February 1, 2016 G1. Notice of Change in Authorization As necessary G4. Permit Application for Substantive Changes to the Discharge As necessary G5. Engineering Report for Construction or Modification Activities As necessary G7. Notice of Permit Transfer As necessary G10. Duty to Provide Information As necessary Page 5 of 35 Permit No. ST 6139 SPECIAL CONDITIONS S1. DISCHARGE LIMITS All discharges and activities authorized by this permit must comply with the terms and conditions of this permit. The discharge of any of the following pollutants more frequently than, or at a concentration in excess of, that authorized by this permit violates the terms and conditions of this permit. A discharge of a pollutant in excess of local limits set by the city of Centralia violates the terms and conditions of this permit. Beginning on the effective date, the Permittee is authorized to discharge wastewater to the city of Centralia sewer system subject to the following limits: Effluent Limits: Outfall 001 Latitude 46.69933 Longitude -122.96170 Parameter Average Monthly a Maximum Daily b Biochemical Oxygen Demand (BOD5) 50 lbs/day 50 lbs/day Total Suspended Solids (TSS) 50 lbs/day 50 lbs/day Oil and Grease 2 lbs/day 2 lbs/day Parameter Minimum Maximum pH 6.0 Standard Units 9.0 Standard Units a Average monthly effluent limit means the highest allowable average of daily discharges over a calendar month. To calculate the discharge value to compare to the limit, you add the value of each daily discharge measured during a calendar month and divide this sum by the total number of daily discharges measured. b Maximum daily effluent limit means the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limits expressed in units of mass, calculate the daily discharge as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day. This does not apply to pH. S2. MONITORING REQUIREMENTS A. Monitoring Requirements The Permittee must monitor the wastewater and production according to the following schedule: The Permittee must monitor in accordance with the following schedule and the requirements specified in Appendix A. Page 6 of 35 Permit No. ST 6139 Parameter Units Sampling Frequency Sample Type (1) Final Wastewater Effluent Flow gpd Monthly Metered BOD5 mg/L Monthly Graba BOD5 lbs/day Monthly Calculated TSS mg/L Monthly Graba TSS lbs/day Monthly Calculated Oil and Grease mg/L Monthly Graba Oil and Grease lbs/day Monthly Calculated TKN mg/L Monthly Graba pH Standard Units Monthly Graba (2) Permit Renewal Application Requirements – Final Wastewater Effluentc Cyanide µg/L Graba Total Phenolic Compounds µg/L Graba Priority Pollutants (PP) – Total Metals µg/L; ng/L for mercury 1/permit cycle 24-Hour Compositeb Graba for Mercury PP – Volatile Organic Compounds µg/L 1/permit cycle Graba PP – Acid-extractable Compounds µg/L 1/permit cycle 24-Hour Compositeb PP – Base-neutral Compounds µg/L 1/permit cycle 24-Hour Compositeb PP - Dioxin pg/L 1/permit cycle 24-Hour Compositeb PP – Pesticides/PCBs µg/L 1/permit cycle 24-Hour Compositeb (3) Effluent Characterization – Final Wastewater Effluentc Cyanide µg/L Graba Total Phenolic Compounds µg/L Graba Priority Pollutants (PP) – Total Metals µg/L; ng/L for mercury 1/permit cycle 24-Hour Compositeb Grab for mercury Page 7 of 35 Permit No. ST 6139 PP – Volatile Organic Compounds µg/L 1/permit cyclec Graba Parameter Units Sampling Frequency Sample Type PP – Acid-extractable Compounds µg/L 1/permit cyclec 24-Hour Compositeb PP – Base-neutral Compounds µg/L 1/permit cyclec 24-Hour Compositeb PP - Dioxin pg/L 1/permit cyclec 24-Hour Compositeb PP – Pesticides/PCBs µg/L 1/permit cyclec 24-Hour Compositeb a Grab means an individual sample collected over a 15 minute, or less, period. b Twenty-four (24)-hour composite means a series of individual samples collected over a 24-hour period into a single container, and analyzed as one sample. c The Permittee is required to submit the priority pollutant scan twice during five year permit cycle. First priority pollutant scan must be submitted by February 1, 2016, and second priority pollutant scan must be submitted by January 2, 2019. B. Sampling and Analytical Procedures Samples and measurements taken to meet the requirements of this permit must represent the volume and nature of the monitored parameters, including representative sampling of any unusual discharge or discharge condition, including bypasses, upsets and maintenance-related conditions affecting effluent quality. Sampling and analytical methods used to meet the water and wastewater monitoring requirements specified in this permit must conform to the latest revision of the following rules and documents unless otherwise specified in this permit or approved in writing by the Department of Ecology (Ecology). • Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 Code of Federal Regulations (CFR) Part 136 • Standard Methods for the Examination of Water and Wastewater (APHA) C. Flow Measurement, Field Measurement, and Continuous Monitoring Devices The Permittee must: 1. Select and use appropriate flow measurement, field measurement, and continuous monitoring devices and methods consistent with accepted scientific practices. 2. Install, calibrate, and maintain these devices to ensure the accuracy of the measurements is consistent with the accepted industry standard, the Page 8 of 35 Permit No. ST 6139 manufacturer’s recommendation, and approved Operation and Maintenance (O&M) Manual procedures for the device and the wastestream. 3. Calibrate flow-monitoring devices at a minimum frequency of at least one calibration per year. 4. Maintain calibration records for at least three years. D. Laboratory Accreditation The Permittee must ensure that all monitoring data required by Ecology for permit specified parameters is prepared by a laboratory registered or accredited under the provisions of chapter 173-50 Washington Administrative Code (WAC), Accreditation of Environmental Laboratories. Flow, temperature, settleable solids, conductivity, pH, and internal process control parameters are exempt from this requirement. The Permittee must obtain accreditation for conductivity and pH if it must receive accreditation or registration for other parameters. E. Request for Reduction in Monitoring The Permittee may request a reduction of the sampling frequency after 12 months of monitoring. Ecology will review each request and at its discretion grant the request when it reissues the permit or by a permit modification. The Permittee must: 1. Provide a written request. 2. Clearly state the parameters for which it is requesting reduced monitoring. 3. Clearly state the justification for the reduction. S3. REPORTING AND RECORDING REQUIREMENTS The Permittee must monitor and report in accordance with the following conditions. Falsification of information submitted to Ecology is a violation of the terms and conditions of this permit. A. Discharge Monitoring Reports The first monitoring period begins on the effective date of the permit (unless otherwise specified). The Permittee must: 1. Summarize, report, and submit monitoring data obtained during each monitoring period on the electronic discharge monitoring report (DMR) form provided by Ecology within the Water Quality Permitting Portal. Include data for each of the parameters tabulated in Special Condition S2 and as required by the form. Report a value for each day sampling occurred (unless specifically exempted in the permit) and for the summary values (when applicable) included on the electronic form. Page 9 of 35 Permit No. ST 6139 To find out more information and to sign up for the Water Quality Permitting Portal go to: http://www.ecy.wa.gov/programs/wq/permits/paris/webdmr.html. 2. Enter the “No Discharge” reporting code for an entire DMR, for a specific monitoring point, or for a specific parameter as appropriate, if the Permittee did not discharge wastewater or a specific pollutant during a given monitoring period. 3. Report single analytical values below detection as “less than the detection level (DL)” by entering < followed by the numeric value of the detection level (e.g. < 2.0) on the DMR. If the method used did not meet the minimum DL and quantitation level (QL) identified in the permit, report the actual QL and DL in the comments or in the location provided. 4. Report the test method used for analysis in the comments if the laboratory used an alternative method not specified in the permit and as allowed in Appendix A. 5. Calculate average values and calculated total values (unless otherwise specified in the permit) using: a. The reported numeric value for all parameters measured between the agency-required detection value and the agency-required quantitation value. b. One-half the detection value (for values reported below detection) if the lab detected the parameter in another sample from the same monitoring point for the reporting period. c. Zero (for values reported below detection) if the lab did not detect the parameter in another sample for the reporting period. 6. Report single-sample grouped parameters (for example: priority pollutants, PAHs, pulp and paper chlorophenolics, TTOs) on the WQWebDMR form and include: sample date, concentration detected, detection limit (DL) (as necessary), and laboratory quantitation level (QL) (as necessary). The Permittee must also submit an electronic copy of the laboratory report as an attachment using WQWebDMR. The contract laboratory reports must also include information on the chain of custody, QA/QC results, and documentation of accreditation for the parameter. 7. Ensure that DMRs are electronically submitted no later than the dates specified below, unless otherwise specified in this permit. 8. Submit DMRs for parameters with the monitoring frequencies specified in S2 at the reporting schedule identified below. The Permittee must: a. Submit monthly DMRs by the 15th day of the following month. b. Submit priority pollutant scan by February 1, 2016. Page 10 of 35 Permit No. ST 6139 c. Submit permit renewal application monitoring data in WQWebDMR as required in Special Condition S2 by January 2, 2019. B. Permit Submittals and Schedules The Permittee must use the Water Quality Permitting Portal – Permit Submittals application (unless otherwise specified in the permit) to submit all other written permit- required reports by the date specified in the permit. When another permit condition requires submittal of a paper (hard-copy) report, the Permittee must ensure that it is postmarked or received by Ecology no later than the dates specified by this permit. Send these paper reports to Ecology at: Water Quality Permit Coordinator Department of Ecology Southwest Regional Office P.O. Box 47775 Olympia, WA 98504-7775 C. Records Retention The Permittee must retain records of all monitoring information for a minimum of three years. Such information must include all calibration and maintenance records and all original recordings for continuous monitoring instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit. The Permittee must extend this period of retention during the course of any unresolved litigation regarding the discharge of pollutants by the Permittee or when requested by Ecology. D. Recording of Results For each measurement or sample taken, the Permittee must record the following information: 1. The date, exact place, method, and time of sampling or measurement. 2. The individual who performed the sampling or measurement. 3. The dates the analyses were performed. 4. The individual who performed the analyses. 5. The analytical techniques or methods used. 6. The results of all analyses. E. Additional Monitoring by the Permittee If the Permittee monitors any pollutant more frequently than required by Condition S2 of this permit, then the Permittee must include the results of such monitoring in the Page 11 of 35 Permit No. ST 6139 calculation and reporting of the data submitted in the Permittee's DMR unless otherwise specified by Condition S2. F. Reporting Permit Violations The Permittee must take the following actions when it violates or is unable to comply with any permit condition: 1. Immediately take action to stop, contain, and cleanup unauthorized discharges or otherwise stop the noncompliance and correct the problem. 2. If applicable, immediately repeat sampling and analysis. Submit the results of any repeat sampling to Ecology within 30 days of sampling. a. Immediate Reporting The Permittee must report any noncompliance that may endanger health or the environment immediately to the Department of Ecology's Regional Office 24-hour number listed below: Southwest Regional Office 360-407-6300 b. Twenty-Four-Hour Reporting The Permittee must report the following occurrences of noncompliance by telephone, to Ecology at the telephone numbers listed above, within 24 hours from the time the Permittee becomes aware of any of the following circumstances. The Permittee must report: i. Any noncompliance that may endanger health or the environment, unless previously reported under immediate reporting requirements. ii. Any unanticipated bypass that causes an exceedance of an effluent limit in the permit (see Part S4.A, “Bypass Procedures”). iii. Any upset that causes an exceedance of an effluent limit in the permit. Upset means an exceptional incident in which there is unintentional and temporary noncompliance with technology- based permit effluent limits because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. iv. Any violation of a maximum daily or instantaneous maximum discharge limit for any of the pollutants in Section S1.A of this permit. Page 12 of 35 Permit No. ST 6139 v. Any overflow prior to the treatment works, whether or not such overflow endangers health or the environment or exceeds any effluent limit in the permit. This requirement does not include industrial process wastewater overflows to impermeable surfaces which are collected and routed to the treatment works. c. Report Within Five Days The Permittee must also submit a written report within five days of the time that the Permittee becomes aware of any reportable event under subparts a or b, above. The report must contain: i. A description of the noncompliance and its cause. ii. The period of noncompliance, including exact dates and times. iii. The estimated time the Permittee expects the noncompliance to continue if not yet corrected. iv. Steps taken or planned to reduce, eliminate, and prevent recurrence of the noncompliance. v. If the noncompliance involves an overflow prior to the treatment works, an estimate of the quantity (in gallons) of untreated overflow. d. Waiver of Written Reports Ecology may waive the written report required in subpart c, above, on a case-by-case basis upon request if the Permittee has submitted a timely oral report. e. All Other Permit Violation Reporting The Permittee must report all permit violations, which do not require immediate or within 24 hours reporting, when it submits monitoring reports for S3.A ("Reporting"). The reports must contain the information listed in subpart c, above. Compliance with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply. G. Other Reporting 1. Spills of Oil or Hazardous Materials The Permittee must report a spill of oil or hazardous materials in accordance with the requirements of Revised Code of Washington (RCW) 90.56.280 and chapter 173-303-145. You can obtain further instructions at the following website: http://www.ecy.wa.gov/programs/spills/other/reportaspill.htm. Page 13 of 35 Permit No. ST 6139 2. Failure to Submit Relevant or Correct Facts Where the Permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application, or in any report to Ecology, it must submit such facts or information promptly. H. Maintaining a Copy of this Permit The Permittee must keep a copy of this permit at the facility and make it available upon request to Ecology inspectors. I. Dangerous Waste Discharge Notification The Permittee must notify the publicly owned treatment works (POTW) and Ecology in writing of the intent to discharge into the POTW any substance designated as a dangerous waste in accordance with the provisions of WAC 173-303-070. It must make this notification at least 90 days prior to the date that it proposes to initiate the discharge. The Permittee must not discharge this substance until authorized by Ecology and the POTW. It must also comply with the notification requirements of Special Condition S8 and General Condition G4. J. Spill Notification The Permittee must notify the POTW immediately (as soon as discovered) of all discharges that could cause problems to the POTW, such as process spills and unauthorized discharges (including slug discharges). S4. OPERATION AND MAINTENANCE The Permittee must, at all times, properly operate and maintain all facilities or systems of treatment and control (and related appurtenances) which are installed to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems, which are installed by a Permittee only when the operation is necessary to achieve compliance with the conditions of this permit. A. Bypass Procedures This permit prohibits a bypass, which is the intentional diversion of waste streams from any portion of a treatment facility. Ecology may take enforcement action against a Permittee for a bypass unless one of the following circumstances (1, 2, or 3) applies. 1. Bypass for essential maintenance without the potential to cause violation of permit limits or conditions. This permit authorizes a bypass if it allows for essential maintenance and does not have the potential to cause violations of limits or other conditions of this permit, or adversely impact public health as determined by Ecology prior to the bypass. The Permittee must submit prior notice, if possible, at least 10 days before the date of the bypass. Page 14 of 35 Permit No. ST 6139 2. Bypass is unavoidable, unanticipated, and results in noncompliance of this permit. This permit authorizes such a bypass only if: a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage. “Severe property damage” means substantial physical damage to property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. b. No feasible alternatives to the bypass exist, such as: • The use of auxiliary treatment facilities. • Retention of untreated wastes. • Stopping production. • Maintenance during normal periods of equipment downtime, but not if the Permittee should have installed adequate backup equipment in the exercise of reasonable engineering judgment to prevent a bypass. • Transport of untreated wastes to another treatment facility. c. The Permittee has properly notified Ecology of the bypass as required in Condition S3.F of this permit. 3. If bypass is anticipated and has the potential to result in noncompliance of this permit. a. The Permittee must notify Ecology at least 30 days before the planned date of bypass. The notice must contain: • A description of the bypass and its cause. • An analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing. • A cost-effectiveness analysis of alternatives including comparative resource damage assessment. • The minimum and maximum duration of bypass under each alternative. • A recommendation as to the preferred alternative for conducting the bypass. • The projected date of bypass initiation. Page 15 of 35 Permit No. ST 6139 • A statement of compliance with State Environmental Policy Act (SEPA). • A request for modification of water quality standards as provided for in WAC 173-201A-410, if an exceedance of any water quality standard is anticipated. • Details of the steps taken or planned to reduce, eliminate, and prevent reoccurrence of the bypass. b. For probable construction bypasses, the Permittee must notify Ecology of the need to bypass as early in the planning process as possible. The Permittee must consider the analysis required above during the project planning and design process. The project-specific engineering report or facilities plan as well as the plans and specifications must include details of probable construction bypasses to the extent practical. In cases where the Permittee determines the probable need to bypass early, the Permittee must continue to analyze conditions up to and including the construction period in an effort to minimize or eliminate the bypass. c. Ecology will consider the following prior to issuing an administrative order for this type of bypass: • If the bypass is necessary to perform construction or maintenance-related activities essential to meet the requirements of this permit. • If feasible alternatives to bypass exist, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production, maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility. • If the Permittee planned and scheduled the bypass to minimize adverse effects on the public and the environment. After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve or deny the request. Ecology will give the public an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Ecology will approve a request to bypass by issuing an administrative order under RCW 90.48.120. S5. PROHIBITED DISCHARGES The Permittee must comply with these General and Specific Prohibitions. A. General Prohibitions The Permittee must not introduce into the POTW pollutant(s), which cause Pass Through or Interference. Page 16 of 35 Permit No. ST 6139 B. Specific Prohibitions In addition, the Permittee must not introduce the following into the POTW: 1. Pollutants which create a fire or explosion hazard in the POTW, including, but not limited to, waste streams with a closed cup flashpoint of less than 60 degrees C (140 degrees F) using the test methods specified in 40 CFR 261.21. 2. Solid or viscous pollutants in amounts, which will cause obstruction to the flow in the POTW resulting in interference. 3. Any pollutant (including oxygen-demanding pollutants (BOD5, etc.), released in a discharge at a flow rate and/or pollutant concentration that will cause interference with the POTW. 4. Heat in amounts which will inhibit biological activity in the POTW resulting in interference, but in no case heat in such quantities that the temperature at the POTW treatment plant exceeds 40 degrees C (104 degrees F) unless the approval authority, upon request of the POTW, approves alternative temperature limits. 5. Petroleum oil, non-biodegradable cutting oil, or products of mineral oil origin in amounts that will cause interference or pass through. 6. Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems. 7. Any trucked or hauled pollutants, except at discharge points designated by the POTW. 8. Pollutants that will cause corrosive structural damage to the POTW. C. Prohibited Unless Approved Any of the following discharges are prohibited unless approved by Ecology under extraordinary circumstances (such as a lack of direct discharge alternatives due to combined sewer service or a need to augment sewage flows due to septic conditions): 1. Noncontact cooling water in significant volumes. 2. Storm water and other direct inflow sources. 3. Wastewaters significantly affecting system hydraulic loading, which do not require treatment or would not be afforded a significant degree of treatment by the system. 4. The discharge of dangerous wastes as defined in Chapter 173-303 WAC (Unless specifically authorized in this permit). S6. DILUTION PROHIBITED The Permittee must not dilute the wastewater discharge with stormwater or increase the use of potable water, process water, noncontact cooling water, or, in any way, attempt to dilute an Page 17 of 35 Permit No. ST 6139 effluent as a partial or complete substitute for adequate treatment to achieve compliance with the limits contained in this permit. S7. APPLICATION FOR PERMIT RENEWAL OR MODIFICATION FOR FACILITY CHANGES The Permittee must submit an application for renewal of this permit by January 2, 2019. The Permittee must also submit a new application or supplement at least 180 days prior to commencement of discharges, resulting from the activities listed below, which may result in permit violations. These activities include any facility expansions, production increases, or other planned changes, such as process modifications, in the permitted facility. S8. NON-ROUTINE AND UNANTICIPATED DISCHARGES A. Beginning on the effective date of this permit, the Permittee is authorized to discharge non-routine wastewater on a case-by-case basis to the sanitary sewer if approved by Ecology and the POTW. Prior to any such discharge, the Permittee must contact Ecology and at a minimum provide the following information: 1. The proposed discharge location 2. The nature of the activity that will generate the discharge 3. Any alternatives to the discharge, such as reuse, storage, or recycling of the water 4. The total volume of water it expects to discharge 5. The results of the chemical analysis of the water 6. The date of proposed discharge 7. The expected rate of discharge discharged, in gallons per day B. The expected rate of discharge in gallons per minute for discharges greater than 20,000 gallons. C. The Permittee must analyze the water for all constituents limited for the discharge and report them as required by subpart 1.e above. The analysis must also include any parameter deemed necessary by Ecology. All discharges must comply with the effluent limits as established in Condition S1 of this permit and any other limits imposed by Ecology. D. The discharge cannot proceed until Ecology has reviewed the information provided and has authorized the discharge by letter to the Permittee or by an Administrative Order. S9. SPILL CONTROL PLAN A. Spill Control Plan Submittals and Requirements The Permittee must: Page 18 of 35 Permit No. ST 6139 1. Submit to Ecology an update to the existing Spill Control Plan by February 1, 2016. 2. Review the plan at least annually and update the spill plan as needed. 3. Send changes to the plan to Ecology. 4. Follow the plan and any supplements throughout the term of the permit. B. Spill Control Plan Components The spill control plan must include the following: 1. A list of all oil and petroleum products and other materials used and/or stored on- site, which when spilled, or otherwise released into the environment, designate as Dangerous Waste (DW) or Extremely Hazardous Waste (EHW) by the procedures set forth in WAC 173-303-070. Include other materials used and/or stored on-site, which may become pollutants or cause pollution upon reaching state's waters. 2. A description of preventive measures and facilities (including an overall facility plot showing drainage patterns) which prevent, contain, or treat spills of these materials. 3. A description of the reporting system the Permittee will use to alert responsible managers and legal authorities in the event of a spill. 4. A description of operator training to implement the plan. The Permittee may submit plans and manuals required by 40 CFR Part 112, contingency plans required by Chapter 173-303 WAC, or other plans required by other agencies, which meet the intent of this section. S10. SLUG DISCHARGE CONTROL PLAN A. Slug Discharge Control Plan Submittal and Requirements The Permittee must: 1. Prepare and submit to Ecology, by February 1, 2016, a plan to minimize the potential of slug discharges from the facility covered by this permit. The Plan and any subsequent revisions become effective 30 days following submission. 2. Review its slug discharge plan and update it as needed. 3. Submit all revisions or updates of this plan to Ecology for review and approval. 4. Keep the current approved plan on the plant site and make it readily available to facility personnel. 5. Follow the approved plan and any approved supplements throughout the term of the permit. Page 19 of 35 Permit No. ST 6139 B. Slug Discharge Control Plan Components The slug discharge control plan must include the following information and procedures relating to the prevention of unauthorized slug discharges; it must include: 1. A description of a reporting system the Permittee will use to immediately notify facility management, the POTW operator, and appropriate state, federal, and local authorities of any slug discharges, and provisions to provide a written follow-up report within five days. 2. A description of operator training, equipment, and facilities (including overall facility plan) for preventing, containing, or treating slug discharges. 3. Procedures to prevent adverse impact from accidental spills including: a. Inspection and maintenance of storage areas b. Handling and transfer of materials c. Loading and unloading operations d. Control of plant site run-off e. Worker training f. Building of containment structures or equipment g. Measures for containing toxic organic pollutants (including solvents) h. Measures and equipment for emergency response 4. A list of all raw materials, products, chemicals, and hazardous materials used, processed, or stored at the facility; the normal quantity maintained on the premises for each listed material; and a map showing where they are located. 5. A description of discharge practices for batch and continuous processes under normal and non-routine circumstances. 6. A brief description of any unauthorized discharges which occurred during the 36- month period preceding the effective date of this permit and subsequent measures taken by Permittee to prevent or to reduce the possibility of further unauthorized discharges. 7. An implementation schedule including additional operator training and procurement and installation of equipment or facilities required to properly implement the plan. Page 20 of 35 Permit No. ST 6139 GENERAL CONDITIONS G1. SIGNATORY REQUIREMENTS All applications, reports, or information submitted to Ecology must be signed as follows: A. All permit applications must be signed by either a principal executive officer or ranking elected official. B. All reports required by this permit and other information requested by Ecology must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by the person described above and is submitted to Ecology at the time of authorization, and 2. The authorization specifies either a named individual or any individual occupying a named position. C. Changes to authorization. If an authorization under paragraph G1.B above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Certification. Any person signing a document under this section must make the following certification: "I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." G2. RIGHT OF ENTRY Representatives of Ecology have the right to enter at all reasonable times in or upon any property, public or private, for the purpose of inspecting and investigating conditions relating to the pollution or the possible pollution of any waters of the state. Reasonable times include normal business hours; hours during which production, treatment, or discharge occurs; or times when Ecology suspects a violation requiring immediate inspection. Representatives of Ecology must be allowed to have access to, and copy at reasonable cost, any records required to be kept under terms and conditions of the permit; to inspect any monitoring equipment or method required in the permit; and to sample the discharge, waste treatment processes, or internal waste streams. Page 21 of 35 Permit No. ST 6139 G3. PERMIT ACTIONS This permit is subject to modification, suspension, or termination, in whole or in part by Ecology for any of the following causes: A. Violation of any permit term or condition; B. Obtaining a permit by misrepresentation or failure to disclose all relevant facts; C. A material change in quantity or type of waste disposal; D. A material change in the condition of the waters of the state; or E. Nonpayment of fees assessed pursuant to RCW 90.48.465. Ecology may also modify this permit, including the schedule of compliance or other conditions, if it determines good and valid cause exists, including promulgation or revisions of regulations or new information. G4. REPORTING A CAUSE FOR MODIFICATION The Permittee must submit a new application, or a supplement to the previous application, along with required engineering plans and reports, whenever a new or increased discharge or change in the nature of the discharge is anticipated which is not specifically authorized by this permit. This application must be submitted at least 180 days prior to any proposed changes. Submission of this application does not relieve the Permittee of the duty to comply with the existing permit until it is modified or reissued. G5. PLAN REVIEW REQUIRED Prior to constructing or modifying any wastewater control facilities, an engineering report and detailed plans and specifications must be submitted to Ecology for approval in accordance with Chapter 173-240 WAC. Engineering reports, plans, and specifications should be submitted at least 180 days prior to the planned start of construction. Facilities must be constructed and operated in accordance with the approved plans. G6. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in the permit excuses the Permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations. G7. TRANSFER OF THIS PERMIT This permit is automatically transferred to a new owner or operator if: A. A written agreement between the old and new owner or operator containing a specific date for transfer of permit responsibility, coverage, and liability is submitted to Ecology; B. A copy of the permit is provided to the new owner and; C. Ecology does not notify the Permittee of the need to modify the permit. Page 22 of 35 Permit No. ST 6139 Unless this permit is automatically transferred according to Section A above, this permit may be transferred only if it is modified to identify the new Permittee and to incorporate such other requirements as determined necessary by Ecology. G8. REDUCED PRODUCTION FOR COMPLIANCE The Permittee must control production or discharge to the extent necessary to maintain compliance with the terms and conditions of this permit upon reduction of efficiency, loss, or failure of its treatment facility until the treatment capacity is restored or an alternative method of treatment is provided. This requirement applies in the situation where, among other things, the primary source of power for the treatment facility is reduced, lost, or fails. G9. REMOVED SUBSTANCES Collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of wastewaters must not be resuspended or reintroduced to the effluent stream for discharge. G10. PAYMENT OF FEES The Permittee must submit payment of fees associated with this permit as assessed by Ecology. Ecology may revoke this permit if the permit fees established under Chapter 173-224 WAC are not paid. G11. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit is guilty of a crime, and upon conviction thereof shall be punished by a fine of up to $10,000 and costs of prosecution, or by imprisonment in the discretion of the court. Each day upon which a willful violation occurs is a separate and additional violation. Any person who violates the terms and conditions of a waste discharge permit incurs, in addition to any other penalty as provided by law, a civil penalty in the amount of up to $10,000 for every such violation. Each and every such violation is a separate and distinct offense, and in case of a continuing violation, every day’s continuance is a separate and distinct violation. G12. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all information which Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology upon request, copies of records required to be kept by this permit. G13. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of chapter 90.48 RCW and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. Page 23 of 35 Permit No. ST 6139 APPENDIX A LIST OF POLLUTANTS WITH ANALYTICAL METHODS, DETECTION LIMITS AND QUANTITATION LEVELS The Permittee must use the specified analytical methods, detection limits (DLs) and quantitation levels (QLs) in the following table for permit and application required monitoring unless: • Another permit condition specifies other methods, detection levels, or quantitation levels. • The method used produces measurable results in the sample and EPA has listed it as an EPA-approved method in 40 CFR Part 136. If the Permittee uses an alternative method, not specified in the permit and as allowed above, it must report the test method, DL, and QL on the discharge monitoring report or in the required report. If the Permittee is unable to obtain the required DL and QL in its effluent due to matrix effects, the Permittee must submit a matrix-specific detection limit (MDL) and a quantitation limit (QL) to Ecology with appropriate laboratory documentation. When the permit requires the Permittee to measure the base neutral compounds in the list of priority pollutants, it must measure all of the base neutral pollutants listed in the table below. The list includes EPA required base neutral priority pollutants and several additional polynuclear aromatic hydrocarbons (PAHs). The Water Quality Program added several PAHs to the list of base neutrals below from Ecology’s Persistent Bioaccumulative Toxics (PBT) List. It only added those PBT parameters of interest to Appendix A that did not increase the overall cost of analysis unreasonably. Ecology added this appendix to the permit in order to reduce the number of analytical “non-detects” in permit-required monitoring and to measure effluent concentrations near or below criteria values where possible at a reasonable cost. CONVENTIONAL PARAMETERS Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Biochemical Oxygen Demand SM5210-B 2 mg/L Chemical Oxygen Demand SM5220-D 10 mg/L Page 24 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Total Organic Carbon SM5310-B/C/D 1 mg/L Total Suspended Solids SM2540-D 5 mg/L Total Ammonia (as N) SM4500-NH3-B and C/D/E/G/H 20 Flow Calibrated device Dissolved oxygen SM4500-OC/OG 0.2 mg/L Temperature (max. 7-day avg.) Analog recorder or Use micro-recording devices known as thermistors 0.2º C pH SM4500-H+ B N/A N/A NONCONVENTIONAL PARAMETERS Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL)2 µg/L unless specified Total Alkalinity SM2320-B 5 mg/L as CaCO3 Chlorine, Total Residual SM4500 Cl G 50.0 Color SM2120 B/C/E 10 color units Fecal Coliform SM 9221E,9222 N/A Specified in method - sample aliquot dependent Fluoride (16984-48-8) SM4500-F E 25 100 Nitrate + Nitrite Nitrogen (as N) SM4500-NO3- E/F/H 100 Nitrogen, Total Kjeldahl (as N) SM4500-NorgB/C and SM4500NH3- 300 Page 25 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL)2 µg/L unless specified B/C/D/EF/G/H Soluble Reactive Phosphorus (as P) SM4500- PE/PF 3 10 Phosphorus, Total (as P) SM 4500 PB followed by SM4500-PE/PF 3 10 Oil and Grease (HEM) 1664 A or B 1,400 5,000 Salinity SM2520-B 3 practical salinity units or scale (PSU or PSS) Settleable Solids SM2540 -F 100 Sulfate (as mg/L SO4) SM4110-B 200 Sulfide (as mg/L S) SM4500-S2F/D/E/G 200 Sulfite (as mg/L SO3) SM4500-SO3B 2000 Total Coliform SM 9221B, 9222B, 9223B N/A Specified in method - sample aliquot dependent Total dissolved solids SM2540 C 20 mg/L Total Hardness SM2340B 200 as CaCO3 Aluminum, Total (7429-90-5) 200.8 2.0 10 Barium Total (7440-39-3) 200.8 0.5 2.0 BTEX (benzene +toluene + ethylbenzene + m,o,p xylenes) EPA SW 846 8021/8260 1 2 Boron Total (7440-42-8) 200.8 2.0 10.0 Cobalt, Total (7440-48-4) 200.8 0.05 0.25 Iron, Total (7439-89-6) 200.7 12.5 50 Magnesium, Total (7439-95-4) 200.7 10 50 Page 26 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL)2 µg/L unless specified Molybdenum, Total (7439-98- 7) 200.8 0.1 0.5 Manganese, Total (7439-96-5) 200.8 0.1 0.5 NWTPH Dx Ecology NWTPH Dx 250 250 NWTPH Gx Ecology NWTPH Gx 250 250 Tin, Total (7440-31-5) 200.8 0.3 1.5 Titanium, Total (7440-32-6) 200.8 0.5 2.5 PRIORITY POLLUTANTS Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified METALS, CYANIDE & TOTAL PHENOLS Antimony, Total (7440-36-0) 200.8 0.3 1.0 Arsenic, Total (7440-38-2) 200.8 0.1 0.5 Beryllium, Total (7440-41-7) 200.8 0.1 0.5 Cadmium, Total (7440-43-9) 200.8 0.05 0.25 Chromium (hex) dissolved (18540-29-9) SM3500-Cr EC 0.3 1.2 Chromium, Total (7440-47-3) 200.8 0.2 1.0 Copper, Total (7440-50-8) 200.8 0.4 2.0 Lead, Total (7439-92-1) 200.8 0.1 0.5 Mercury, Total (7439-97-6) 1631E 0.0002 0.0005 Nickel, Total (7440-02-0) 200.8 0.1 0.5 Page 27 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Selenium, Total (7782-49-2) 200.8 1.0 1.0 Silver, Total (7440-22-4) 200.8 0.04 0.2 Thallium, Total (7440-28-0) 200.8 0.09 0.36 Zinc, Total (7440-66-6) 200.8 0.5 2.5 Cyanide, Total (57-12-5) 335.4 5 10 Cyanide, Weak Acid Dissociable SM4500-CN I 5 10 Cyanide, Free Amenable to Chlorination (Available Cyanide) SM4500-CN G 5 10 Phenols, Total EPA 420.1 50 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified ACID COMPOUNDS 2-Chlorophenol (95-57-8) 625 1.0 2.0 2,4-Dichlorophenol (120-83-2) 625 0.5 1.0 2,4-Dimethylphenol (105-67-9) 625 0.5 1.0 4,6-dinitro-o-cresol (534-52-1) (2-methyl-4,6,-dinitrophenol) 625/1625B 1.0 2.0 2,4 dinitrophenol (51-28-5) 625 1.0 2.0 2-Nitrophenol (88-75-5) 625 0.5 1.0 4-nitrophenol (100-02-7) 625 0.5 1.0 Page 28 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Parachlorometa cresol (59-50- 7) (4-chloro-3-methylphenol) 625 1.0 2.0 Pentachlorophenol (87-86-5) 625 0.5 1.0 Phenol (108-95-2) 625 2.0 4.0 2,4,6-Trichlorophenol (88-06-2) 625 2.0 4.0 VOLATILE COMPOUNDS Acrolein (107-02-8) 624 5 10 Acrylonitrile (107-13-1) 624 1.0 2.0 Benzene (71-43-2) 624 1.0 2.0 Bromoform (75-25-2) 624 1.0 2.0 Carbon tetrachloride (56-23-5) 624/601 or SM6230B 1.0 2.0 Chlorobenzene (108-90-7) 624 1.0 2.0 Chloroethane (75-00-3) 624/601 1.0 2.0 2-Chloroethylvinyl Ether (110-75-8) 624 1.0 2.0 Chloroform (67-66-3) 624 or SM6210B 1.0 2.0 Dibromochloromethane (124-48-1) 624 1.0 2.0 1,2-Dichlorobenzene (95-50-1) 624 1.9 7.6 1,3-Dichlorobenzene (541-73-1) 624 1.9 7.6 1,4-Dichlorobenzene (106-46-7) 624 4.4 17.6 Page 29 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Dichlorobromomethane (75-27- 4) 624 1.0 2.0 1,1-Dichloroethane (75-34-3) 624 1.0 2.0 1,2-Dichloroethane (107-06-2) 624 1.0 2.0 1,1-Dichloroethylene (75-35-4) 624 1.0 2.0 1,2-Dichloropropane (78-87-5) 624 1.0 2.0 1,3-dichloropropene (mixed isomers) (1,2- dichloropropylene) (542-75-6) 3 624 1.0 2.0 Ethylbenzene (100-41-4) 624 1.0 2.0 Methyl bromide (74-83-9) (Bromomethane) 624/601 5.0 10.0 Methyl chloride (74-87-3) (Chloromethane) 624 1.0 2.0 Methylene chloride (75-09-2) 624 5.0 10.0 1,1,2,2-Tetrachloroethane (79-34-5) 624 1.9 2.0 Tetrachloroethylene (127-18-4) 624 1.0 2.0 Toluene (108-88-3) 624 1.0 2.0 1,2-Trans-Dichloroethylene (156-60-5) (Ethylene dichloride) 624 1.0 2.0 1,1,1-Trichloroethane (71-55-6) 624 1.0 2.0 1,1,2-Trichloroethane (79-00-5) 624 1.0 2.0 Trichloroethylene (79-01-6) 624 1.0 2.0 Page 30 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Vinyl chloride (75-01-4) 624/SM6200B 1.0 2.0 BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs) Acenaphthene (83-32-9) 625 0.2 0.4 Acenaphthylene (208-96-8) 625 0.3 0.6 Anthracene (120-12-7) 625 0.3 0.6 Benzidine (92-87-5) 625 12 24 Benzyl butyl phthalate (85-68-7) 625 0.3 0.6 Benzo(a)anthracene (56-55-3) 625 0.3 0.6 Benzo(b)fluoranthene (3,4-benzofluoranthene) (205-99-2) 4 610/625 0.8 1.6 Benzo(j)fluoranthene (205-82-3) 4 625 0.5 1.0 Benzo(k)fluoranthene (11,12-benzofluoranthene) (207-08-9) 4 610/625 0.8 1.6 Benzo(r,s,t)pentaphene (189-55-9) 625 0.5 1.0 Benzo(a)pyrene (50-32-8) 610/625 0.5 1.0 Benzo(ghi)Perylene (191-24-2) 610/625 0.5 1.0 Bis(2-chloroethoxy)methane (111-91-1) 625 5.3 21.2 Bis(2-chloroethyl)ether (111- 44-4) 611/625 0.3 1.0 Bis(2-chloroisopropyl)ether (39638-32-9) 625 0.3 0.6 Page 31 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Bis(2-ethylhexyl)phthalate (117-81-7) 625 0.1 0.5 4-Bromophenyl phenyl ether (101-55-3) 625 0.2 0.4 2-Chloronaphthalene (91-58-7) 625 0.3 0.6 4-Chlorophenyl phenyl ether (7005-72-3) 625 0.3 0.5 Chrysene (218-01-9) 610/625 0.3 0.6 Dibenzo (a,h)acridine (226-36-8) 610M/625M 2.5 10.0 Dibenzo (a,j)acridine (224-42-0) 610M/625M 2.5 10.0 Dibenzo(a-h)anthracene (53-70-3)(1,2,5,6- dibenzanthracene) 625 0.8 1.6 Dibenzo(a,e)pyrene (192-65-4) 610M/625M 2.5 10.0 Dibenzo(a,h)pyrene (189-64-0) 625M 2.5 10.0 3,3-Dichlorobenzidine (91-94- 1) 605/625 0.5 1.0 Diethyl phthalate (84-66-2) 625 1.9 7.6 Dimethyl phthalate (131-11-3) 625 1.6 6.4 Di-n-butyl phthalate (84-74-2) 625 0.5 1.0 2,4-dinitrotoluene (121-14-2) 609/625 0.2 0.4 2,6-dinitrotoluene (606-20-2) 609/625 0.2 0.4 BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs) Di-n-octyl phthalate (117-84-0) 625 0.3 0.6 Page 32 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified 1,2-Diphenylhydrazine (as Azobenzene) (122-66-7) 1625B 5.0 20 Fluoranthene (206-44-0) 625 0.3 0.6 Fluorene (86-73-7) 625 0.3 0.6 Hexachlorobenzene (118-74-1) 612/625 0.3 0.6 Hexachlorobutadiene (87-68-3) 625 0.5 1.0 Hexachlorocyclopentadiene (77-47-4) 1625B/625 0.5 1.0 Hexachloroethane (67-72-1) 625 0.5 1.0 Indeno(1,2,3-cd)Pyrene (193-39-5) 610/625 0.5 1.0 Isophorone (78-59-1) 625 0.5 1.0 3-Methyl cholanthrene (56-49-5) 625 2.0 8.0 Naphthalene (91-20-3) 625 0.3 0.6 Nitrobenzene (98-95-3) 625 0.5 1.0 N-Nitrosodimethylamine (62- 75-9) 607/625 2.0 4.0 N-Nitrosodi-n-propylamine (621-64-7) 607/625 0.5 1.0 N-Nitrosodiphenylamine (86- 30-6) 625 0.5 1.0 Perylene (198-55-0) 625 1.9 7.6 Phenanthrene (85-01-8) 625 0.3 0.6 Pyrene (129-00-0) 625 0.3 0.6 Page 33 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified 1,2,4-Trichlorobenzene (120-82-1) 625 0.3 0.6 DIOXIN 2,3,7,8-Tetra-Chlorodibenzo-P- Dioxin (176-40-16) (2,3,7,8 TCDD) 1613B 1.3 pg/L 5 pg/L PESTICIDES/PCBs Aldrin (309-00-2) 608 0.025 0.05 alpha-BHC (319-84-6) 608 0.025 0.05 beta-BHC (319-85-7) 608 0.025 0.05 gamma-BHC (58-89-9) 608 0.025 0.05 delta-BHC (319-86-8) 608 0.025 0.05 Chlordane (57-74-9) 5 608 0.025 0.05 4,4’-DDT (50-29-3) 608 0.025 0.05 4,4’-DDE (72-55-9) 608 0.025 0.0510 4,4’ DDD (72-54-8) 608 0.025 0.05 Dieldrin (60-57-1) 608 0.025 0.05 alpha-Endosulfan (959-98-8) 608 0.025 0.05 beta-Endosulfan (33213-65-9) 608 0.025 0.05 Endosulfan Sulfate (1031-07- 8) 608 0.025 0.05 Endrin (72-20-8) 608 0.025 0.05 Endrin Aldehyde (7421-93-4) 608 0.025 0.05 Heptachlor (76-44-8) 608 0.025 0.05 Page 34 of 35 Permit No. ST 6139 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Heptachlor Epoxide (1024-57- 3) 608 0.025 0.05 PCB-1242 (53469-21-9) 6 608 0.25 0.5 PCB-1254 (11097-69-1) 608 0.25 0.5 PCB-1221 (11104-28-2) 608 0.25 0.5 PCB-1232 (11141-16-5) 608 0.25 0.5 PCB-1248 (12672-29-6) 608 0.25 0.5 PCB-1260 (11096-82-5) 608 0.13 0.5 PCB-1016 (12674-11-2) 6 608 0.13 0.5 Toxaphene (8001-35-2) 608 0.24 0.5 1. Detection level (DL) or detection limit means the minimum concentration of an analyte (substance) that can be measured and reported with a 99% confidence that the analyte concentration is greater than zero as determined by the procedure given in 40 CFR part 136, Appendix B. 2. Quantitation Level (QL) also known as Minimum Level of Quantitation (ML) – The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that the lab has used all method-specified sample weights, volumes, and cleanup procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest to (1, 2, or 5) x 10n, where n is an integer. (64 FR 30417). ALSO GIVEN AS: The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) achieves the objectives of the intended purpose. (Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency December 2007). 3. Soluble Biochemical Oxygen Demand method note: First, filter the sample through a Millipore Nylon filter (or equivalent) - pore size of 0.45-0.50 um (prep all filters by filtering 250 ml of laboratory grade deionized water through the filter and discard). Then, analyze sample as per method 5210-B. Page 35 of 35 Permit No. ST 6139 4. NWTPH Dx - Northwest Total Petroleum Hydrocarbons Diesel Extended Range – see http://www.ecy.wa.gov/biblio/97602.html 5. NWTPH Gx - Northwest Total Petroleum Hydrocarbons Gasoline Extended Range – see http://www.ecy.wa.gov/biblio/97602.html 6. 1, 3-dichloroproylene (mixed isomers) You may report this parameter as two separate parameters: cis-1, 3-dichlorpropropene (10061-01-5) and trans-1, 3-dichloropropene (10061-02-6). 7. Total Benzofluoranthenes - Because Benzo(b)fluoranthene, Benzo(j)fluoranthene and Benzo(k)fluoranthene co-elute you may report these three isomers as total benzofluoranthenes. 8. Chlordane – You may report alpha-chlordane (5103-71-9) and gamma-chlordane (5103-74-2) in place of chlordane (57-74-9). If you report alpha and gamma-chlordane, the DL/PQLs that apply are 0.025/0.050. 9. PCB 1016 & PCB 1242 – You may report these two PCB compounds as one parameter called PCB 1016/1242. Page 1 of 30 Permit No. ST 6220 Issuance Date: May 12, 2014 Effective Date: June 1, 2014 Expiration Date: May 31, 2019 STATE WASTE DISCHARGE PERMIT NO. ST 6220 STATE OF WASHINGTON DEPARTMENT OF ECOLOGY SOUTHWEST REGIONAL OFFICE In compliance with the provisions of the State of Washington Water Pollution Control Law Chapter 90.48 Revised Code of Washington, as amended, And The Federal Water Pollution Control Act (The Clean Water Act) Title 33 United States Code, Section 1251 et seq Sierra Pacific Industries Centralia Lumber Manufacturing Company 3115 Kuper Road Centralia, WA 98531 is authorized discharge wastewater in accordance with the special and general conditions which follow. Facility Address:: Sierra Pacific Industries Lumber Manufacturing Facility 3115 Kuper Road Centralia, WA 98531 Discharge Location: Latitude: 46.755769 Longitude: -122.994286 Publicly Owned Treatment Works (POTW) Receiving Discharge: The city of Centralia’s Wastewater Treatment Plant Industry Type: Sawmill SIC Code: 2421 Richard Doenges Southwest Region Manager Water Quality Program Washington State Department of Ecology Page 2 of 30 Permit No. ST 6220 TABLE OF CONTENTS SUMMARY OF PERMIT REPORT SUBMITTALS .................................................................................. 4 SPECIAL CONDITIONS S1. DISCHARGE LIMITS .................................................................................................................... 5 S2. MONITORING REQUIREMENT .................................................................................................. 5 A. Wastewater Monitoring B. Sampling and Analytical Procedures C. Flow Measurement D. Laboratory Accreditation E. Request for Reduction in Monitoring S3. REPORTING AND RECORDKEEPING REQUIREMENTS ....................................................... 8 A. Reporting B. Records Retention C. Recording of Results D. Additional Monitoring by the Permittee E. Reporting Permit Violations F. Other Reporting G Maintaining a Copy of This Permit H Dangerous Waste Discharge Notification I Spill Notification S4. OPERATION AND MAINTENANCE ......................................................................................... 13 A. Operations and Maintenance Manual B. Bypass Procedures S5. PROHIBITED DISCHARGES ...................................................................................................... 16 A. General Prohibitions B. Specific Prohibitions C. Prohibited Unless Approved S6. DILUTION PROHIBITED ............................................................................................................ 17 S7. APPLICATION FOR PERMIT RENEWAL ................................................................................ 17 S8. NON-ROUTINE AND UNANTICIPATED DISCHARGES ....................................................... 17 S9. SPILL PLAN ................................................................................................................................. 18 S10. SLUG DISCHARGE CONTROL PLAN ...................................................................................... 19 GENERAL CONDITIONS G1. SIGNATORY REQUIREMENTS ................................................................................................. 20 G2. RIGHT OF ENTRY ....................................................................................................................... 20 G3. PERMIT ACTIONS ....................................................................................................................... 21 G4. REPORTING A CAUSE FOR MODIFICATION ........................................................................ 21 G5. PLAN REVIEW REQUIRED ....................................................................................................... 21 Page 3 of 30 Permit No. ST 6220 G6. COMPLIANCE WITH OTHER LAWS AND STATUTES ......................................................... 21 G7. TRANSFER OF THIS PERMIT ................................................................................................... 21 G8. REDUCED PRODUCTION FOR COMPLIANCE ...................................................................... 22 G9. REMOVED SUBSTANCES ......................................................................................................... 22 G10. PAYMENT OF FEES .................................................................................................................... 22 G11. PENALTIES FOR VIOLATING PERMIT CONDITIONS .......................................................... 22 G12. DUTY TO PROVIDE INFORMATION ....................................................................................... 22 G13. DUTY TO COMPLY .................................................................................................................... 22 APPENDIX A ............................................................................................................................................ 23 Page 4 of 30 Permit No. ST 6220 SUMMARY OF PERMIT REPORT SUBMITTALS Refer to the Special and General Conditions of this permit for additional submittal requirements. Permit Section Submittal Frequency First Submittal Date S3.A. Discharge Monitoring Report Quarterly July 15, 2014 S3.E Noncompliance Notification As necessary S4.A. Operation and Maintenance (O&M) Manual 1/permit cycle January 2, 2018 S4.A. O&M Manual Update/Review Letter Annually January 2, 2015 S4.B Reporting Bypasses As necessary S7. Application for Permit Renewal 1/permit cycle January 2, 2018 S9.A. Spill Plan 1/permit cycle January 2, 2018 S10. Slug Discharge Control Plan 1/permit cycle January 2, 2018 G1. Notice of Change in Authorization As necessary G4. Permit Application for Substantive Changes to the Discharge As necessary G5. Engineering Report for Construction or Modification Activities As necessary G7. Notice of Permit Transfer As necessary Page 5 of 30 Permit No. ST 6220 SPECIAL CONDITIONS S1. DISCHARGE LIMITS All discharges and activities authorized by this permit must comply with the terms and conditions of this permit. The discharge of any of the following pollutants more frequently than, or at a concentration in excess of, that authorized by this permit violates the terms and conditions of this permit. Beginning on the effective date of this permit, the Permittee is authorized to discharge the boiler blowdown and Reverse Osmosis (RO) concentrate to the city of Centralia’s wastewater collection system through the discharge point 001 (Outfall 001), subject to the following limits: EFFLUENT LIMITS – OUTFALL 001 Parameter Average Quarterly a Maximum Daily b Flow (GPD) 13,040 26,880 Temperature (°C) --- Report c BOD5 (mg/L) --- 300 TSS (mg/L) --- 300 Oil & Grease (mg/L) --- 100 pH (Standard Units) Daily minimum is equal to or greater than 6.0 and the daily maximum is less than or equal to 9.0 a Average Quarterly effluent limit means the highest allowable average of daily discharges over a calendar quarter. To calculate the discharge value to compare to the limit, you add the value of each daily discharge measured during a calendar quarter and divide this sum by the total number of daily discharges measured. b Maximum daily effluent means the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limits expressed in units of mass, the daily discharge is calculated as the total mass of pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day. This does not apply to pH. c See permit condition S5.B.5. S2. MONITORING REQUIREMENT A. Wastewater Monitoring The Permittee must monitor the wastewater in accordance with the following schedule and requirements specified in Appendix A, before this wastewater is discharged to the city of Centralia’s sanitary sewer system. Page 6 of 30 Permit No. ST 6220 Parameter Units Location Sample Frequency Sample Type Flow GPD Wastewater Storage Tank Continuous a Metered pH Standard Units Wastewater Storage Tank Daily Grab Temperature °C Wastewater Storage Tank Monthly Grab BOD5 mg/L Wastewater Storage Tank Quarterly b Composite c TSS mg/L Wastewater Storage Tank Quarterly b Composite c TDS mg/L Wastewater Storage Tank Quarterly b Grab Chloride mg/L Wastewater Storage Tank Quarterly b Grab Oil & Grease mg/L Wastewater Storage Tank Quarterly b Grab Arsenic µg/L Wastewater Storage Tank Quarterly b Composite c Cadmium µg/L Wastewater Storage Tank Quarterly b Composite c Chromium µg/L Wastewater Storage Tank Quarterly b Composite c Copper µg/L Wastewater Storage Tank Quarterly b Composite c Lead µg/L Wastewater Storage Tank Quarterly b Composite c Molybdenum µg/L Wastewater Storage Tank Quarterly b Composite c Nickel µg/L Wastewater Storage Tank Quarterly b Composite c Selenium µg/L Wastewater Storage Tank Quarterly b Composite c Silver µg/L Wastewater Storage Tank Quarterly b Composite c Zinc µg/L Wastewater Storage Tank Quarterly b Composite c a Continuous means uninterrupted except for brief lengths of time for calibration, for power failure, or for un-anticipated equipment repair or maintenance. Sampling must be Page 7 of 30 Permit No. ST 6220 Parameter Units Location Sample Frequency Sample Type taken monthly when continuous monitoring is not possible. b Quarterly is defined as January through March, April through June, July through September, and October through December. c Composite sample must consist of a minimum of four grab samples, each collected at least one hour apart. B. Sampling and Analytical Procedures Samples and measurements taken to meet the requirements of this permit must represent the volume and nature of the monitored parameters, including representative sampling of any unusual discharge or discharge condition, including bypasses, upsets, and maintenance-related conditions affecting effluent quality. Sampling and analytical methods used to meet the water and wastewater monitoring requirements specified in this permit must conform to the latest revision of the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 Code of Federal Regulations (CFR) Part 136 or to the latest revision of Standard Methods for the Examination of Water and Wastewater (American Public Health Association), unless otherwise specified in this permit or approved in writing by the Department of Ecology (Ecology). C. Flow Measurement The Permittee must: 1. Select and use appropriate flow measurement, field measurement, and continuous monitoring devices and methods consistent with accepted scientific practices. 2. Install, calibrate, and maintain these devices to ensure the accuracy of the measurements is consistent with the accepted industry standard and the manufacturer’s recommendation for that type of device. 3. Use field measurement devices as directed by the manufacturer and do not use reagents beyond their expiration dates. 4. Calibrate these devices at the frequency recommended by the manufacturer. 5. Calibrate flow monitoring devices at a minimum frequency of at least one calibration per year. 6. Maintain calibration records for at least three years. D. Laboratory Accreditation The Permittee must ensure that all monitoring data required by Ecology is prepared by a laboratory registered or accredited under the provisions of chapter 173-50 Administrative Code (WAC), Accreditation of Environmental Laboratories. Flow, temperature, Page 8 of 30 Permit No. ST 6220 settleable solids, conductivity, pH, and internal process control parameters are exempt from this requirement. The Permittee must obtain accreditation for conductivity and pH if it must receive accreditation or registration for other parameters. E. Request for Reduction in Monitoring The Permittee may request a reduction of the sampling frequency after 12 months of monitoring. Ecology will review each request and at its discretion grant the request through a permit modification or when it reissues the permit. The Permittee must: 1. Provide a written request. 2. Clearly state the parameters for which it is requesting reduced monitoring. 3. Clearly state the justification for the reduction. S3. REPORTING AND RECORDKEEPING REQUIREMENTS The Permittee must monitor and report in accordance with the following conditions. Falsification of information submitted to Ecology is a violation of the terms and conditions of this permit. A. Reporting The first monitoring period begins on the effective date of the permit. The Permittee must: 1. Summarize, report, and submit monitoring data obtained during each monitoring period on the electronic Discharge Monitoring Report (DMR) form provided by Ecology within WAWebDMR. Include data for each of the parameters tabulated in Special Condition S2 and as required by the form. Report a value for each day sampling occurred (unless specifically exempted in the permit) and for the summary values (when applicable) included on the electronic form. To find out more information and to sign up for WAWebDMR go to: http://www.ecy.wa.gov/programs/wq/permits/paris/webdmr.html If unable to submit electronically (for example, if you do not have an internet connection), the Permittee must contact Ecology to request a waiver and obtain instructions on how to obtain a paper copy DMR. 2. Enter the “No Discharge” reporting code for an entire DMR, for a specific monitoring point, or for a specific parameter as appropriate, if the Permittee did not discharge wastewater or a specific pollutant during a given monitoring period. 3. Report single analytical values below detection as “less than the detection level (DL)” by entering < followed by the numeric value of the detection level (e.g. < 2.0) on the DMR. If the method used did not meet the minimum DL and Page 9 of 30 Permit No. ST 6220 quantitation level (QL) identified in the permit, report the actual QL and DL in the comments or in the location provided. 4. Report the test method used for analysis in the comments if the laboratory used an alternative method not specified in the permit and as allowed in Appendix A. 5. Calculate average values (unless otherwise specified in the permit) using: a. The reported numeric value for all parameters measured between the agency-required detection value and the agency-required quantitation value. b. One-half the detection value (for values reported below detection) if the lab detected the parameter in another sample for the reporting period. c. Zero (for values reported below detection) if the lab did not detect the parameter in another sample for the reporting period. 6. Report single-sample grouped parameters (for example priority pollutants, PAHs, pulp and paper chlorophenolics, TTOs) on the WAWebDMR form and include: sample date, concentration detected, detection limit (DL) (as necessary), and laboratory quantitation level (QL) (as necessary). The Permittee must also submit an electronic PDF copy of the laboratory report using WAWebDMR. If the Permittee has obtained a waiver from electronic reporting or if submitting prior to the compliance date, the Permittee must submit a paper copy of the laboratory report providing the following information: date sampled, sample location, date of analysis, parameter name, CAS number, analytical method/number, detection limit (DL), laboratory quantitation level (QL), reporting units, and concentration detected. The contract laboratory reports must also include information on the chain of custody, QA/QC results, and documentation of accreditation for the parameter. 7. Ensure that DMRs are electronically submitted no later than the dates specified below, unless otherwise specified in this permit. If the Permittee has obtained a waiver, it must ensure that paper forms are postmarked or received by Ecology no later than the dates specified below, unless otherwise specified in this permit. 8. Submit DMRs for parameters with the monitoring frequencies specified in S2 (monthly, quarterly, annual, etc.) at the reporting schedule identified below. The Permittee must: a. Submit quarterly DMRs, unless otherwise specified in the permit, by the 15th day of the month following the monitoring period. Quarterly sampling periods are January through March, April through June, July through September, and October through December. Page 10 of 30 Permit No. ST 6220 9. Submit reports to Ecology online using Ecology’s electronic WAWebDMR submittal forms (electronic DMRs) as required above. Send paper reports to Ecology at: Water Quality Permit Coordinator Department of Ecology Southwest Regional Office P.O. Box 47775 Olympia, WA 98504-7775 B. Records Retention The Permittee must retain records of all monitoring information for a minimum of three years. Such information must include all calibration and maintenance records and all original recordings for continuous monitoring instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit. The Permittee must extend this period of retention during the course of any unresolved litigation regarding the discharge of pollutants by the Permittee or when requested by Ecology. C. Recording of Results For each measurement or sample taken, the Permittee must record the following information: 1. The date, exact place, method, and time of sampling or measurement 2. The individual who performed the sampling or measurement 3. The dates the analyses were performed 4. The individual who performed the analyses 5. The analytical techniques or methods used 6. The results of all analyses D. Additional Monitoring by the Permittee If the Permittee monitors any pollutant more frequently than required by Condition S2 of this permit, then the Permittee must include the results of such monitoring in the calculation and reporting of the data submitted in the Permittee's DMR unless otherwise specified by Condition S2. E. Reporting Permit Violations The Permittee must take the following actions when it violates or is unable to comply with any permit condition: 1. Immediately take action to stop, contain, and cleanup unauthorized discharges or otherwise stop the noncompliance and correct the problem. Page 11 of 30 Permit No. ST 6220 2. If applicable, immediately repeat sampling and analysis. Submit the results of any repeat sampling to Ecology within 30 days of sampling. a. Immediate Reporting The Permittee must report any noncompliance that may endanger health or the environment immediately to the Department of Ecology's Regional Office 24-hr. number listed below: Southwest Regional Office 360-407-6300 b. Twenty-Four-Hour Reporting The Permittee must report the following occurrences of noncompliance by telephone, to Ecology at 360-407-6300, within 24 hours from the time the Permittee becomes aware of any of the following circumstances. The Permittee must report: i. Any noncompliance that may endanger health or the environment, unless previously reported under immediate reporting requirements. ii. Any unanticipated bypass that causes an exceedance of an effluent limit in the permit (See Part S4.B., “Bypass Procedures”). iii. Any upset that causes an exceedance of an effluent limit in the permit. Upset means an exceptional incident in which there is unintentional and temporary noncompliance with technology- based permit effluent limits because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. iv. Any violation of a maximum daily or instantaneous maximum discharge limit for any of the pollutants in Section S1.A of this permit. v. Any overflow prior to the treatment works, whether or not such overflow endangers health or the environment or exceeds any effluent limit in the permit. c. Report Within Five Days The Permittee must also submit a written report within five days of the time that the Permittee becomes aware of any reportable event under subparts a or b, above. The report must contain: i. A description of the noncompliance and its cause. Page 12 of 30 Permit No. ST 6220 ii. The period of noncompliance, including exact dates and times. iii. The estimated time the Permittee expects the noncompliance to continue if not yet corrected. iv. Steps taken or planned to reduce, eliminate, and prevent recurrence of the noncompliance. v. If the noncompliance involves an overflow prior to the treatment works, an estimate of the quantity (in gallons) of untreated overflow. d. Waiver of Written Reports Ecology may waive the written report required in subpart c, above, on a case-by-case basis upon request if the Permittee has submitted a timely oral report. e. All Other Permit Violation Reporting The Permittee must report all permit violations, which do not require immediate or within 24 hours reporting, when it submits monitoring reports for S3.A ("Reporting"). The reports must contain the information listed in subpart c, above. Compliance with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply. f. Report Submittal The Permittee must submit reports to the address listed in S3.A.9. F. Other Reporting 1. Spills of Oil or Hazardous Materials The Permittee must report a spill of oil or hazardous materials in accordance with the requirements of RCW 90.56.280 and chapter 173-303-145. You can obtain further instructions at the following website: http://www.ecy.wa.gov/programs/spills/other/reportaspill.htm . 2. Failure to Submit Relevant or Correct Facts Where the Permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application, or in any report to Ecology, it must submit such facts or information promptly. G. Maintaining a Copy of this Permit The Permittee must keep a copy of this permit at the facility and make it available upon request to Ecology inspectors. Page 13 of 30 Permit No. ST 6220 H. Dangerous Waste Discharge Notification The Permittee must notify the publicly owned treatment works (POTW) and Ecology in writing of the intent to discharge into the POTW any substance designated as a dangerous waste in accordance with the provisions of WAC 173-303-070. It must make this notification at least 90 days prior to the date that it proposes to initiate the discharge. The Permittee must not discharge this substance until authorized by Ecology and the POTW. It must also comply with the notification requirements of Special Condition S8 and General Condition G4. I. Spill Notification The Permittee must notify the POTW immediately (as soon as discovered) of all discharges that could cause problems to the POTW, such as process spills and unauthorized discharges (including slug discharges). S4. OPERATION AND MAINTENANCE The Permittee must, at all times, properly operate and maintain all facilities or systems of treatment and control (and related appurtenances) which are installed to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems, which are installed by a Permittee only when the operation is necessary to achieve compliance with the conditions of this permit. A. Operations and Maintenance Manual The Permittee must: 1. Prepare an Operations and Maintenance (O&M) Manual in accordance with WAC 173-240-150 and submit it to Ecology for approval by January 2, 2018. 2. Review the O&M Manual at least annually and confirm this review by letter to Ecology by January 2nd of each year. 3. Submit to Ecology for review and approval substantial changes or updates to the O&M Manual whenever it incorporates them into the manual. 4. Keep the approved O&M Manual at the permitted facility. 5. Follow the instructions and procedures of this manual. In addition to the requirements of WAC 173-240-150(1) and (2), the O&M manual must include: 1. Emergency procedures for plant shutdown and cleanup in event of wastewater system upset, spill, failure, or demand by the POTW treating the discharge. 2. Wastewater system maintenance procedures that contribute to the generation of process wastewater. Page 14 of 30 Permit No. ST 6220 3. Any directions to maintenance staff when cleaning, or maintaining other equipment or performing other tasks which are necessary to protect the operation of the wastewater system (for example, defining maximum allowable discharge rate for draining a tank, blocking all floor drains before beginning the overhaul of a stationary engine.) 4. Wastewater sampling protocols and procedures for compliance with the sampling and reporting requirements in the wastewater discharge permit. 5. Minimum staffing adequate to operate and maintain the treatment processes and carry out compliance monitoring required by the permit. 6. Treatment plant process control monitoring schedule. B. Bypass Procedures This permit prohibits a bypass which is the intentional diversion of waste streams from any portion of a treatment facility. Ecology may take enforcement action against a Permittee for a bypass unless one of the following circumstances (1, 2, or 3) applies. 1. Bypass is for essential maintenance without the potential to cause violation of permit limits or conditions. This permit authorizes a bypass if it allows for essential maintenance and does not have the potential to cause violations of limits or other conditions of this permit, or adversely impact public health as determined by Ecology prior to the bypass. The Permittee must submit prior notice, if possible, at least 10 days before the date of the bypass. 2. Bypass is unavoidable, unanticipated, and results in noncompliance with the conditions of this permit. This permit authorizes such a bypass only if: a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage. “Severe property damage” means substantial physical damage to property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. b. No feasible alternatives to the bypass exist, such as: • The use of auxiliary treatment facilities. • Retention of untreated wastes. • Stopping production. • Maintenance during normal periods of equipment downtime, but not if the Permittee should have installed adequate backup Page 15 of 30 Permit No. ST 6220 equipment in the exercise of reasonable engineering judgment to prevent a bypass. • Transport of untreated wastes to another treatment facility. c. The Permittee has properly notified Ecology of the bypass as required in Condition S3.E of this permit. 3. If bypass is anticipated and has the potential to result in noncompliance of this permit. a. The Permittee must notify Ecology at least 30 days before the planned date of bypass. The notice must contain: • A description of the bypass and its cause. • An analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing. • A cost-effectiveness analysis of alternatives including comparative resource damage assessment. • The minimum and maximum duration of bypass under each alternative. • A recommendation as to the preferred alternative for conducting the bypass. • The projected date of bypass initiation. • A statement of compliance with State Environmental Policy Act (SEPA). • A request for modification of water quality standards as provided for in WAC 173-201A-410, if an exceedance of any water quality standard is anticipated. • Details of the steps taken or planned to reduce, eliminate, and prevent reoccurrence of the bypass. b. For probable construction bypasses, the Permittee must notify Ecology of the need to bypass as early in the planning process as possible. The Permittee must consider the analysis required above during preparation of the engineering report or facilities plan and plans and specifications and must include these to the extent practical. In cases where the Permittee determines the probable need to bypass early, the Permittee must continue to analyze conditions up to and including the construction period in an effort to minimize or eliminate the bypass. c. Ecology will consider the following prior to issuing an administrative Page 16 of 30 Permit No. ST 6220 order for this type of bypass: • If the bypass is necessary to perform construction or maintenance-related activities essential to meet the requirements of this permit. • If feasible alternatives to bypass exist, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production, maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility. • If the Permittee planned and scheduled the bypass to minimize adverse effects on the public and the environment. After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve or deny the request. Ecology will give the public an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Ecology will approve a request to bypass by issuing an administrative order under RCW 90.48.120. S5. PROHIBITED DISCHARGES A. General Prohibitions The Permittee must not introduce into the POTW pollutant(s) which cause Pass Through or Interference. B. Specific Prohibitions In addition, the following must not be introduced into the POTW: 1. Pollutants which create a fire or explosion hazard in the POTW, including, but not limited to, waste streams with a closed cup flashpoint of less than 60oC (140oF) using the test methods specified in 40 CFR 261.21. 2. Solid or viscous pollutants in amounts which will cause obstruction to the flow in the POTW resulting in interference. 3. Any pollutant, including oxygen demanding pollutants (BOD, etc.), released in a discharge at a flow rate and/or pollutant concentration which will cause interference with the POTW. 4. Heat in amounts which will inhibit biological activity in the POTW resulting in interference, but in no case heat in such quantities that the temperature at the POTW treatment plant exceeds 40°C (104°F) unless the approval authority, upon request of the POTW, approves alternative temperature limits. Page 17 of 30 Permit No. ST 6220 5. Petroleum oil, non-biodegradable cutting oil, or products of mineral oil origin in amounts that will cause interference or pass through. 6. Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems. 7. Any trucked or hauled pollutants, except at discharge points designated by the POTW. 8. Pollutants which will cause corrosive structural damage to the POTW, but in no case discharges with pH lower than 5.0 or greater than 11.0, unless the collection and treatment system is specifically designed to accommodate such discharges. C. Prohibited Unless Approved 1. Any of the following discharges are prohibited unless approved by Ecology under extraordinary circumstances (such as a lack of direct discharge alternatives due to combined sewer service or a need to augment sewage flows due to septic conditions): a. Noncontact cooling water in significant volumes. b. Storm water and other direct inflow sources. c. Wastewaters significantly affecting system hydraulic loading, which do not require treatment or would not be afforded a significant degree of treatment by the system. 2. Unless specifically authorized in this permit, the discharge of dangerous wastes as defined in Chapter 173-303 WAC, is prohibited. S6. DILUTION PROHIBITED The Permittee must not dilute the wastewater discharge with stormwater or increase the use of potable water, process water, noncontact cooling water, or, in any way, attempt to dilute an effluent as a partial or complete substitute for adequate treatment to achieve compliance with the limits contained in this permit. S7. APPLICATION FOR PERMIT RENEWAL The Permittee must submit an application for renewal of this permit by January 2, 2018. S8. NON-ROUTINE AND UNANTICIPATED DISCHARGES Beginning on the effective date of this permit, the Permittee is authorized to discharge non- routine wastewater on a case-by-case basis if approved by Ecology and the POTW. Prior to any such discharge, the Permittee must contact Ecology and the POTW and at a minimum provide the following information: 1. The proposed discharge location. Page 18 of 30 Permit No. ST 6220 2. The nature of the activity that will generate the discharge. 3. Any alternatives to the discharge, such as reuse, storage or recycling of the water. 4. The total volume of water it expects to discharge. 5. The results of the chemical analysis of the water. The Permittee must analyze the water for all constituents limited for the discharge. The analysis must also include hardness, any metals that are limited by water quality standards, and any other parameter deemed necessary by Ecology. All discharges must comply with the effluent limits as established in Condition S1 of this permit, water quality standards, and any other limits imposed by Ecology. 6. The date of the proposed discharge. 7. The expected rate of discharge discharged, in gallons per minute. The discharge cannot proceed until Ecology has reviewed the information provided and has authorized the discharge by letter to the Permittee or by an Administrative Order. S9. SPILL PLAN The Permittee must: A. Submit to Ecology a Spill Control Plan for the prevention, containment, and control of spills or unplanned releases of pollutants by January 2, 2018. B. Review the plan at least annually and update the Spill Plan as needed. C. Send changes to the plan to Ecology. D. Follow the Plan and any supplements throughout the term of the permit. The spill control plan must include the following: ● A list of all oil and petroleum products and other materials used and/or stored on site, which when spilled, or otherwise released into the environment, designate as Dangerous (DW) or Extremely Hazardous Waste (EHW) by the procedures set forth in WAC 173- 303-070. Include other materials used and/or stored on site which may become pollutants or cause pollution upon reaching state's waters. ● A description of preventive measures and facilities (including an overall facility plot showing drainage patterns) which prevent, contain, or treat spills of these materials. ● A description of the reporting system the Permittee will use to alert responsible managers and legal authorities in the event of a spill. ● A description of operator training to implement the plan. Page 19 of 30 Permit No. ST 6220 The Permittee may submit plans and manuals required by 40 CFR Part 112, contingency plans required by Chapter 173-303 WAC, or other plans required by other agencies which meet the intent of this section. S10. SLUG DISCHARGE CONTROL PLAN If required to also complete a spill plan as described in S9, the Permittee may combine it with the slug discharge control plan described in this section. By January 2, 2018, the Permittee must prepare and submit to Ecology a plan to minimize the potential of slug discharges from the facility covered by this permit. The plan and any subsequent revisions become effective 30 days following submission. The plan must include the following information and procedures relating to the prevention of unauthorized slug discharges: A. A description of a reporting system the Permittee will use to immediately notify facility management, the POTW operator, and appropriate state, federal, and local authorities of any slug discharges, and provisions to provide a written follow-up report within five days; B. A description of operator training, equipment, and facilities (including overall facility plan) for preventing, containing, or treating slug discharges; C. A list of all raw materials, products, chemicals, and hazardous materials used, processed, or stored at the facility; the normal quantity maintained on the premises for each listed material; and a map showing where they are located. D. A description of discharge practices for batch and continuous processes under normal and non-routine circumstances; E. A brief description of any unauthorized discharges which occurred during the 36-month period preceding the effective date of this permit and subsequent measures taken by Permittee to prevent or to reduce the possibility of further unauthorized discharges; and F. An implementation schedule including additional operator training and procurement and installation of equipment or facilities required to properly implement the plan. The Permittee must: ● Review its slug discharge plan and update it as needed but no less than every two years. ● Submit all revisions or updates of this plan to Ecology for review and approval. ● Maintain the current approved plan on the plant site and make it readily available to facility personnel. ● The Permittee must submit an update of the Slug Discharge Control Plan, or a certification that it is current with the application for permit renewal. Page 20 of 30 Permit No. ST 6220 GENERAL CONDITIONS G1. SIGNATORY REQUIREMENTS All applications, reports, or information submitted to Ecology must be signed as follows: A. All permit applications must be signed by either a principal executive officer or ranking elected official. B. All reports required by this permit and other information requested by Ecology must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by the person described above and is submitted to Ecology at the time of authorization, and 2. The authorization specifies either a named individual or any individual occupying a named position. C. Changes to authorization. If an authorization under paragraph B.2 above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Certification. Any person signing a document under this section must make the following certification: "I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." G2. RIGHT OF ENTRY Representatives of Ecology must have the right to enter at all reasonable times in or upon any property, public or private, for the purpose of inspecting and investigating conditions relating to the pollution or the possible pollution of any waters of the state. Reasonable time includes normal business hours; hours during which production, treatment, or discharge occurs; or times when Ecology suspects a violation requiring immediate inspection. Representatives of Ecology must be allowed to have access to, and copy at reasonable cost, any records required to be kept under terms and conditions of the permit; to inspect any monitoring equipment or method required in the permit; and to sample the discharge, waste treatment processes, or internal waste streams. Page 21 of 30 Permit No. ST 6220 G3. PERMIT ACTIONS This permit is subject to modification, suspension, or termination, in whole or in part by Ecology for any of the following causes: A. Violation of any permit term or condition; B. Obtaining a permit by misrepresentation or failure to disclose all relevant facts; C. A material change in quantity or type of waste disposal; D. A material change in the condition of the waters of the state; or E. Nonpayment of fees assessed pursuant to RCW 90.48.465. Ecology may also modify this permit, including the schedule of compliance or other conditions, if the agency determines good and valid cause exists, including promulgation or revisions of regulations or new information. G4. REPORTING A CAUSE FOR MODIFICATION The Permittee must submit a new application, or a supplement to the previous application, along with required engineering plans and reports, whenever a new or increased discharge or change in the nature of the discharge is anticipated which is not specifically authorized by this permit. This application must be submitted at least 60 days prior to any proposed changes. Submission of this application does not relieve the Permittee of the duty to comply with the existing permit until it is modified or reissued. G5. PLAN REVIEW REQUIRED Prior to constructing or modifying any wastewater control facilities, an engineering report and detailed plans and specifications must be submitted to Ecology for approval in accordance with Chapter 173-240 WAC. Engineering reports, plans, and specifications should be submitted at least 180 days prior to the planned start of construction. Facilities must be constructed and operated in accordance with the approved plans. G6. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in the permit excuses the Permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations. G7. TRANSFER OF THIS PERMIT This permit is automatically transferred to a new owner or operator if: A. A written agreement between the old and new owner or operator containing a specific date for transfer of permit responsibility, coverage, and liability is submitted to Ecology; B. A copy of the permit is provided to the new owner and the receiving POTW is notified and; Page 22 of 30 Permit No. ST 6220 C. Ecology does not notify the Permittee of the need to modify the permit. Unless this permit is automatically transferred according to subsection A. above, this permit may be transferred only if it is modified to identify the new Permittee and to incorporate such other requirements as determined necessary by Ecology. G8. REDUCED PRODUCTION FOR COMPLIANCE The Permittee must control production or discharge to the extent necessary to maintain compliance with the terms and conditions of this permit upon reduction of efficiency, loss, or failure of its treatment facility until the treatment capacity is restored or an alternative method of treatment is provided. This requirement applies in the situation where, among other things, the primary source of power for the treatment facility is reduced, lost, or fails. G9. REMOVED SUBSTANCES Collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of wastewaters must not be resuspended or reintroduced to the effluent stream for discharge. G10. PAYMENT OF FEES The Permittee must submit payment of fees associated with this permit as assessed by Ecology. Ecology may revoke this permit if the permit fees established under Chapter 173-224 WAC are not paid. G11. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit is guilty of a crime, and upon conviction thereof will be punished by a fine of up to $10,000 and costs of prosecution, or by imprisonment in the discretion of the court. Each day upon which a willful violation occurs is a separate and additional violation. Any person who violates the terms and conditions of a waste discharge permit will incur, in addition to any other penalty as provided by law, a civil penalty in the amount of up to $10,000 for every such violation. Each and every such violation is a separate and distinct offense, and in case of a continuing violation, every day’s continuance is a separate and distinct violation. G12. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all information which Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology upon request, copies of records required to be kept by this permit. G13. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. Page 23 of 30 Permit No. ST 6220 APPENDIX A LIST OF POLLUTANTS WITH ANALYTICAL METHODS, DETECTION LIMITS AND QUANTITATION LEVELS The Permittee must use the specified analytical methods, detection limits (DLs) and quantitation levels (QLs) in the following table for permit and application required monitoring unless: • Another permit condition specifies other methods, detection levels, or quantitation levels. • The method used produces measurable results in the sample and EPA has listed it as an EPA- approved method in 40 CFR Part 136. If the Permittee uses an alternative method, not specified in the permit and as allowed above, it must report the test method, DL, and QL on the discharge monitoring report or in the required report. If the Permittee is unable to obtain the required DL and QL in its effluent due to matrix effects, the Permittee must submit a matrix-specific detection limit (MDL) and a quantitation limit (QL) to Ecology with appropriate laboratory documentation. When the permit requires the Permittee to measure the base neutral compounds in the list of priority pollutants, it must measure all of the base neutral pollutants listed in the table below. The list includes EPA required base neutral priority pollutants and several additional polynuclear aromatic hydrocarbons (PAHs). The Water Quality Program added several PAHs to the list of base neutrals below from Ecology’s Persistent Bioaccumulative Toxics (PBT) List. It only added those PBT parameters of interest to Appendix A that did not increase the overall cost of analysis unreasonably. Ecology added this appendix to the permit in order to reduce the number of analytical “non-detects” in permit-required monitoring and to measure effluent concentrations near or below criteria values where possible at a reasonable cost. CONVENTIONAL PARAMETERS Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Biochemical Oxygen Demand SM5210-B 2 mg/L Chemical Oxygen Demand SM5220-D 10 mg/L Total Organic Carbon SM5310-B/C/D 1 mg/L Total Suspended Solids SM2540-D 5 mg/L Total Ammonia (as N) SM4500-NH3-B and C/D/E/G/H 20 Flow Calibrated device Dissolved oxygen SM4500-OC/OG 0.2 mg/L Temperature (max. 7-day avg.) Analog recorder or Use micro-recording devices known as thermistors 0.2º C pH SM4500-H+ B N/A N/A Page 24 of 30 Permit No. ST 6220 NONCONVENTIONAL PARAMETERS Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL)2 µg/L unless specified Total Alkalinity SM2320-B 5 mg/L as CaCO3 Chlorine, Total Residual SM4500 Cl G 50.0 Color SM2120 B/C/E 10 color units Fecal Coliform SM 9221E,9222 N/A Specified in method - sample aliquot dependent Fluoride (16984-48-8) SM4500-F E 25 100 Nitrate + Nitrite Nitrogen (as N) SM4500-NO3- E/F/H 100 Nitrogen, Total Kjeldahl (as N) SM4500-NorgB/C and SM4500NH3-B/C/D/EF/G/H 300 Soluble Reactive Phosphorus (as P) SM4500- PE/PF 3 10 Phosphorus, Total (as P) SM 4500 PB followed by SM4500-PE/PF 3 10 Oil and Grease (HEM) 1664 A or B 1,400 5,000 Salinity SM2520-B 3 practical salinity units or scale (PSU or PSS) Settleable Solids SM2540 -F 100 Sulfate (as mg/L SO4) SM4110-B 200 Sulfide (as mg/L S) SM4500-S2F/D/E/G 200 Sulfite (as mg/L SO3) SM4500-SO3B 2000 Total Coliform SM 9221B, 9222B, 9223B N/A Specified in method - sample aliquot dependent Total dissolved solids SM2540 C 20 mg/L Total Hardness SM2340B 200 as CaCO3 Aluminum, Total (7429-90-5) 200.8 2.0 10 Barium Total (7440-39-3) 200.8 0.5 2.0 BTEX (benzene +toluene + ethylbenzene + m,o,p xylenes) EPA SW 846 8021/8260 1 2 Boron Total (7440-42-8) 200.8 2.0 10.0 Cobalt, Total (7440-48-4) 200.8 0.05 0.25 Iron, Total (7439-89-6) 200.7 12.5 50 Magnesium, Total (7439-95-4) 200.7 10 50 Molybdenum, Total (7439-98- 7) 200.8 0.1 0.5 Manganese, Total (7439-96-5) 200.8 0.1 0.5 NWTPH Dx Ecology NWTPH Dx 250 250 NWTPH Gx Ecology NWTPH Gx 250 250 Page 25 of 30 Permit No. ST 6220 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL)2 µg/L unless specified Tin, Total (7440-31-5) 200.8 0.3 1.5 Titanium, Total (7440-32-6) 200.8 0.5 2.5 PRIORITY POLLUTANTS Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified METALS, CYANIDE & TOTAL PHENOLS Antimony, Total (7440-36-0) 200.8 0.3 1.0 Arsenic, Total (7440-38-2) 200.8 0.1 0.5 Beryllium, Total (7440-41-7) 200.8 0.1 0.5 Cadmium, Total (7440-43-9) 200.8 0.05 0.25 Chromium (hex) dissolved (18540-29-9) SM3500-Cr EC 0.3 1.2 Chromium, Total (7440-47-3) 200.8 0.2 1.0 Copper, Total (7440-50-8) 200.8 0.4 2.0 Lead, Total (7439-92-1) 200.8 0.1 0.5 Mercury, Total (7439-97-6) 1631E 0.0002 0.0005 Nickel, Total (7440-02-0) 200.8 0.1 0.5 Selenium, Total (7782-49-2) 200.8 1.0 1.0 Silver, Total (7440-22-4) 200.8 0.04 0.2 Thallium, Total (7440-28-0) 200.8 0.09 0.36 Zinc, Total (7440-66-6) 200.8 0.5 2.5 Cyanide, Total (57-12-5) 335.4 5 10 Cyanide, Weak Acid Dissociable SM4500-CN I 5 10 Cyanide, Free Amenable to Chlorination (Available Cyanide) SM4500-CN G 5 10 Phenols, Total EPA 420.1 50 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified ACID COMPOUNDS 2-Chlorophenol (95-57-8) 625 1.0 2.0 2,4-Dichlorophenol (120-83-2) 625 0.5 1.0 2,4-Dimethylphenol (105-67-9) 625 0.5 1.0 4,6-dinitro-o-cresol (534-52-1) (2-methyl-4,6,-dinitrophenol) 625/1625B 1.0 2.0 2,4 dinitrophenol (51-28-5) 625 1.0 2.0 2-Nitrophenol (88-75-5) 625 0.5 1.0 4-nitrophenol (100-02-7) 625 0.5 1.0 Page 26 of 30 Permit No. ST 6220 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Parachlorometa cresol (59-50- 7) (4-chloro-3-methylphenol) 625 1.0 2.0 Pentachlorophenol (87-86-5) 625 0.5 1.0 Phenol (108-95-2) 625 2.0 4.0 2,4,6-Trichlorophenol (88-06-2) 625 2.0 4.0 VOLATILE COMPOUNDS Acrolein (107-02-8) 624 5 10 Acrylonitrile (107-13-1) 624 1.0 2.0 Benzene (71-43-2) 624 1.0 2.0 Bromoform (75-25-2) 624 1.0 2.0 Carbon tetrachloride (56-23-5) 624/601 or SM6230B 1.0 2.0 Chlorobenzene (108-90-7) 624 1.0 2.0 Chloroethane (75-00-3) 624/601 1.0 2.0 2-Chloroethylvinyl Ether (110-75-8) 624 1.0 2.0 Chloroform (67-66-3) 624 or SM6210B 1.0 2.0 Dibromochloromethane (124-48-1) 624 1.0 2.0 1,2-Dichlorobenzene (95-50-1) 624 1.9 7.6 1,3-Dichlorobenzene (541-73-1) 624 1.9 7.6 1,4-Dichlorobenzene (106-46- 7) 624 4.4 17.6 Dichlorobromomethane (75-27- 4) 624 1.0 2.0 1,1-Dichloroethane (75-34-3) 624 1.0 2.0 1,2-Dichloroethane (107-06-2) 624 1.0 2.0 1,1-Dichloroethylene (75-35-4) 624 1.0 2.0 1,2-Dichloropropane (78-87-5) 624 1.0 2.0 1,3-dichloropropene (mixed isomers) (1,2- dichloropropylene) (542-75-6) 3 624 1.0 2.0 Ethylbenzene (100-41-4) 624 1.0 2.0 Methyl bromide (74-83-9) (Bromomethane) 624/601 5.0 10.0 Methyl chloride (74-87-3) (Chloromethane) 624 1.0 2.0 Methylene chloride (75-09-2) 624 5.0 10.0 1,1,2,2-Tetrachloroethane (79-34-5) 624 1.9 2.0 Tetrachloroethylene (127-18-4) 624 1.0 2.0 Toluene (108-88-3) 624 1.0 2.0 Page 27 of 30 Permit No. ST 6220 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified 1,2-Trans-Dichloroethylene (156-60-5) (Ethylene dichloride) 624 1.0 2.0 1,1,1-Trichloroethane (71-55-6) 624 1.0 2.0 1,1,2-Trichloroethane (79-00-5) 624 1.0 2.0 Trichloroethylene (79-01-6) 624 1.0 2.0 Vinyl chloride (75-01-4) 624/SM6200B 1.0 2.0 BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs) Acenaphthene (83-32-9) 625 0.2 0.4 Acenaphthylene (208-96-8) 625 0.3 0.6 Anthracene (120-12-7) 625 0.3 0.6 Benzidine (92-87-5) 625 12 24 Benzyl butyl phthalate (85-68-7) 625 0.3 0.6 Benzo(a)anthracene (56-55-3) 625 0.3 0.6 Benzo(b)fluoranthene (3,4-benzofluoranthene) (205- 99-2) 4 610/625 0.8 1.6 Benzo(j)fluoranthene (205-82- 3) 4 625 0.5 1.0 Benzo(k)fluoranthene (11,12-benzofluoranthene) (207-08-9) 4 610/625 0.8 1.6 Benzo(r,s,t)pentaphene (189-55-9) 625 0.5 1.0 Benzo(a)pyrene (50-32-8) 610/625 0.5 1.0 Benzo(ghi)Perylene (191-24-2) 610/625 0.5 1.0 Bis(2-chloroethoxy)methane (111-91-1) 625 5.3 21.2 Bis(2-chloroethyl)ether (111- 44-4) 611/625 0.3 1.0 Bis(2-chloroisopropyl)ether (39638-32-9) 625 0.3 0.6 Bis(2-ethylhexyl)phthalate (117-81-7) 625 0.1 0.5 4-Bromophenyl phenyl ether (101-55-3) 625 0.2 0.4 2-Chloronaphthalene (91-58-7) 625 0.3 0.6 4-Chlorophenyl phenyl ether (7005-72-3) 625 0.3 0.5 Chrysene (218-01-9) 610/625 0.3 0.6 Dibenzo (a,h)acridine (226-36-8) 610M/625M 2.5 10.0 Dibenzo (a,j)acridine (224-42-0) 610M/625M 2.5 10.0 Page 28 of 30 Permit No. ST 6220 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Dibenzo(a-h)anthracene (53-70-3)(1,2,5,6-dibenzanthracene) 625 0.8 1.6 Dibenzo(a,e)pyrene (192-65-4) 610M/625M 2.5 10.0 Dibenzo(a,h)pyrene (189-64-0) 625M 2.5 10.0 3,3-Dichlorobenzidine (91-94-1) 605/625 0.5 1.0 Diethyl phthalate (84-66-2) 625 1.9 7.6 Dimethyl phthalate (131-11-3) 625 1.6 6.4 Di-n-butyl phthalate (84-74-2) 625 0.5 1.0 2,4-dinitrotoluene (121-14-2) 609/625 0.2 0.4 2,6-dinitrotoluene (606-20-2) 609/625 0.2 0.4 BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs) Di-n-octyl phthalate (117-84-0) 625 0.3 0.6 1,2-Diphenylhydrazine (as Azobenzene) (122-66-7) 1625B 5.0 20 Fluoranthene (206-44-0) 625 0.3 0.6 Fluorene (86-73-7) 625 0.3 0.6 Hexachlorobenzene (118-74-1) 612/625 0.3 0.6 Hexachlorobutadiene (87-68-3) 625 0.5 1.0 Hexachlorocyclopentadiene (77-47-4) 1625B/625 0.5 1.0 Hexachloroethane (67-72-1) 625 0.5 1.0 Indeno(1,2,3-cd)Pyrene (193-39-5) 610/625 0.5 1.0 Isophorone (78-59-1) 625 0.5 1.0 3-Methyl cholanthrene (56-49-5) 625 2.0 8.0 Naphthalene (91-20-3) 625 0.3 0.6 Nitrobenzene (98-95-3) 625 0.5 1.0 N-Nitrosodimethylamine (62- 75-9) 607/625 2.0 4.0 N-Nitrosodi-n-propylamine (621-64-7) 607/625 0.5 1.0 N-Nitrosodiphenylamine (86-30-6) 625 0.5 1.0 Perylene (198-55-0) 625 1.9 7.6 Phenanthrene (85-01-8) 625 0.3 0.6 Pyrene (129-00-0) 625 0.3 0.6 1,2,4-Trichlorobenzene (120-82-1) 625 0.3 0.6 DIOXIN 2,3,7,8-Tetra-Chlorodibenzo-P-Dioxin (176-40-16) (2,3,7,8 TCDD) 1613B 1.3 pg/L 5 pg/L Page 29 of 30 Permit No. ST 6220 PESTICIDES/PCBs Aldrin (309-00-2) 608 0.025 0.05 alpha-BHC (319-84-6) 608 0.025 0.05 beta-BHC (319-85-7) 608 0.025 0.05 gamma-BHC (58-89-9) 608 0.025 0.05 delta-BHC (319-86-8) 608 0.025 0.05 Chlordane (57-74-9) 5 608 0.025 0.05 4,4’-DDT (50-29-3) 608 0.025 0.05 4,4’-DDE (72-55-9) 608 0.025 0.0510 4,4’ DDD (72-54-8) 608 0.025 0.05 Dieldrin (60-57-1) 608 0.025 0.05 alpha-Endosulfan (959-98-8) 608 0.025 0.05 beta-Endosulfan (33213-65-9) 608 0.025 0.05 Endosulfan Sulfate (1031-07-8) 608 0.025 0.05 Endrin (72-20-8) 608 0.025 0.05 Endrin Aldehyde (7421-93-4) 608 0.025 0.05 Heptachlor (76-44-8) 608 0.025 0.05 Heptachlor Epoxide (1024-57- 3) 608 0.025 0.05 PCB-1242 (53469-21-9) 6 608 0.25 0.5 PCB-1254 (11097-69-1) 608 0.25 0.5 PCB-1221 (11104-28-2) 608 0.25 0.5 PCB-1232 (11141-16-5) 608 0.25 0.5 PCB-1248 (12672-29-6) 608 0.25 0.5 PCB-1260 (11096-82-5) 608 0.13 0.5 PCB-1016 (12674-11-2) 6 608 0.13 0.5 Toxaphene (8001-35-2) 608 0.24 0.5 1. Detection level (DL) or detection limit means the minimum concentration of an analyte (substance) that can be measured and reported with a 99% confidence that the analyte concentration is greater than zero as determined by the procedure given in 40 CFR part 136, Appendix B. 2. Quantitation Level (QL) also known as Minimum Level of Quantitation (ML) – The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that the lab has used all method-specified sample weights, volumes, and cleanup procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest to (1, 2, or 5) x 10n, where n is an integer. (64 FR 30417). ALSO GIVEN AS: The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) achieves the objectives of the intended purpose. (Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency December 2007). Page 30 of 30 Permit No. ST 6220 3. Soluble Biochemical Oxygen Demand method note: First, filter the sample through a Millipore Nylon filter (or equivalent) - pore size of 0.45-0.50 um (prep all filters by filtering 250 ml of laboratory grade deionized water through the filter and discard). Then, analyze sample as per method 5210-B. 4. NWTPH Dx - Northwest Total Petroleum Hydrocarbons Diesel Extended Range – see http://www.ecy.wa.gov/biblio/97602.html 5. NWTPH Gx - Northwest Total Petroleum Hydrocarbons Gasoline Extended Range – see http://www.ecy.wa.gov/biblio/97602.html 6. 1, 3-dichloroproylene (mixed isomers) You may report this parameter as two separate parameters: cis-1, 3-dichlorpropropene (10061-01-5) and trans-1, 3-dichloropropene (10061-02-6). 7. Total Benzofluoranthenes - Because Benzo(b)fluoranthene, Benzo(j)fluoranthene and Benzo(k)fluoranthene co-elute you may report these three isomers as total benzofluoranthenes. 8. Chlordane – You may report alpha-chlordane (5103-71-9) and gamma-chlordane (5103-74-2) in place of chlordane (57-74-9). If you report alpha and gamma-chlordane, the DL/PQLs that apply are 0.025/0.050. 9. PCB 1016 & PCB 1242 – You may report these two PCB compounds as one parameter called PCB 1016/1242. Lewis County Interlocal Agreement Appendix D Infiltration and Inflow (I/I) Analysis and City Completed Projects to Address I/I City of Centralia Inflow Analysis Date Q (MGD)Precip. (in.)Q (gpcd)Year Average Annual Flow (mgd) Sewered Population 1/12/2011 3.48 0.90 211 2011 1.86 14,060 1/13/2011 4.81 0.40 292 2012 2.15 15,570 1/14/2011 4.63 0.10 281 2013 1.96 15,570 1/15/2011 5.22 0.60 318 2014 1.69 15,570 1/16/2011 6.40 0.60 390 2015 1.94 15,570 1/17/2011 6.11 0.00 372 1/18/2011 5.29 0.20 321 Inflow: non excessive if average daily flow during periods of heavy rainfall < 275 gpcd 1/19/2011 5.00 0.00 304 Data Source: National Oceanic and Atmospheric Administration (NOAA) 1/20/2011 4.65 0.00 283 Flow Data Source: City of Centralia Discharge Monitor Reports 1/21/2011 4.51 0.20 275 3/9/2011 3.85 0.90 234 3/10/2011 5.66 0.60 345 3/11/2011 5.19 0.00 316 3/12/2011 4.86 0.20 296 3/13/2011 4.86 0.30 295 3/14/2011 4.75 0.30 289 3/15/2011 5.29 0.40 322 3/16/2011 5.16 0.20 314 3/17/2011 4.92 0.00 299 3/18/2011 4.64 0.04 282 1/17/2012 1.57 0.79 94 1/18/2012 1.57 0.04 94 1/19/2012 2.94 0.62 176 1/20/2012 4.43 0.63 266 1/21/2012 5.24 0.30 314 1/22/2012 4.77 0.14 286 3/10/2012 2.32 0.20 139 3/11/2012 2.48 0.97 149 3/12/2012 3.24 0.10 194 3/13/2012 4.01 0.37 240 3/14/2012 4.55 0.41 273 3/15/2012 5.88 0.75 353 3/16/2012 6.04 0.31 363 3/17/2012 6.01 0.29 361 3/18/2012 5.56 0.05 334 3/19/2012 4.83 0.00 290 3/27/2012 2.92 0.12 175 3/28/2012 3.01 0.23 180 3/29/2012 6.00 1.38 360 3/30/2012 6.59 0.24 395 3/31/2012 6.69 0.59 401 4/1/2012 6.10 0.14 366 4/2/2012 5.39 0.00 324 4/3/2012 4.83 0.16 290 11/16/2012 1.33 0.14 80 11/17/2012 1.63 0.46 98 11/18/2012 2.47 0.66 148 11/19/2012 5.57 1.73 334 11/29/2012 1.74 0.11 104 11/30/2012 3.65 1.59 219 12/1/2012 5.06 0.37 304 12/2/2012 5.89 1.28 353 12/3/2012 6.22 0.33 373 12/4/2012 6.54 0.51 393 12/5/2012 5.99 0.02 360 12/6/2012 4.94 0.08 296 12/15/2012 2.57 0.19 154 12/16/2012 3.51 0.58 210 12/17/2012 4.32 0.41 259 12/18/2012 4.10 0.13 246 12/19/2012 5.55 1.07 333 12/20/2012 6.55 0.18 393 12/21/2012 6.10 0.04 366 12/22/2012 5.24 0.14 314 12/23/2012 4.92 0.36 295 12/24/2012 4.57 0.02 274 12/25/2012 3.74 0.56 224 12/26/2012 5.11 0.09 307 2/14/2014 1.83 0.27 110 2/15/2014 2.27 0.50 137 2/16/2014 3.63 0.64 218 2/17/2014 6.28 0.66 378 2/18/2014 5.67 0.33 341 2/19/2014 5.27 0.25 316 2/20/2014 4.90 0.23 294 3/2/2014 2.29 0.20 137 3/3/2014 2.60 0.32 156 3/4/2014 2.56 0.07 154 3/5/2014 2.34 0.04 141 3/6/2014 5.54 0.44 333 3/7/2014 4.61 0.01 277 3/8/2014 5.12 0.60 307 3/9/2014 6.20 0.04 373 3/10/2014 5.94 0.19 357 3/11/2014 5.03 0.00 302 1/4/2015 3.57 1.30 213 1/5/2015 6.48 1.50 386 1/6/2015 6.50 0.00 387 1/7/2015 6.40 0.01 381 1/8/2015 5.10 0.00 304 2/4/2015 1.79 0.31 106 2/5/2015 2.41 0.42 143 2/6/2015 3.55 0.41 212 2/7/2015 5.02 0.86 299 2/8/2015 4.96 0.24 295 11/11/2015 1.25 0.23 74 11/12/2015 1.35 0.15 80 11/13/2015 3.69 1.34 220 11/14/2015 5.20 1.88 310 11/15/2015 5.36 0.58 319 11/16/2015 4.73 0.36 282 11/17/2015 7.74 1.24 461 11/18/2015 7.13 0.12 425 11/19/2015 5.42 0.09 323 12/1/2015 1.75 0.58 104 12/2/2015 1.95 0.06 116 12/3/2015 2.25 0.36 134 12/4/2015 2.35 0.21 140 12/5/2015 2.29 0.09 137 12/6/2015 2.30 0.10 137 12/7/2015 3.78 0.92 225 12/8/2015 7.73 1.35 460 12/9/2015 8.66 0.35 516 12/10/2015 8.67 0.84 516 12/11/2015 8.18 0.16 487 12/12/2015 7.89 0.27 470 12/13/2015 7.41 0.15 442 12/14/2015 6.43 0.00 383 12/15/2015 5.47 0.01 326 12/16/2015 4.81 0.05 287 12/17/2015 6.20 0.97 369 12/18/2015 7.74 0.51 461 12/19/2015 7.22 0.05 430 12/20/2015 6.85 0.31 408 12/21/2015 7.65 0.71 456 12/22/2015 7.39 0.15 440 12/23/2015 7.94 0.74 473 12/24/2015 8.03 0.05 478 12/25/2015 7.07 0.00 421 12/26/2015 6.21 0.00 370 12/27/2015 5.60 0.19 334 12/28/2015 4.88 0.01 290 City of Centralia Infiltration Analysis Date Q (MGD) Precip. (in.)Q (gpcd) Average Daily Dry Weather Q (gpcd)Year Average Annual Flow (mgd) Sewered Population 4/27/2012 2.28 0.01 137 2011 1.86 14,060 4/28/2012 2.17 0.05 130 2012 2.15 15,570 4/29/2012 2.17 0.09 130 2013 1.96 15,570 4/30/2012 2.23 0.25 134 2014 1.69 15,570 5/1/2012 2.14 0.00 129 2015 1.94 15,570 5/2/2012 2.10 0.00 126 5/3/2012 2.90 0.00 174 5/4/2012 2.81 0.00 169 Infiltration: non excessive if average dry weather daily flow < 120 gpcd 5/5/2012 2.68 0.00 161 Rainfall Data Source: National Oceanic and Atmospheric Administration (NOAA) 5/6/2012 2.53 0.00 152 Flow Data Source: City of Centralia Discharge Monitor Reports 5/7/2012 2.32 0.00 139 5/8/2012 2.15 0.00 129 5/9/2012 2.00 0.00 120 5/10/2012 1.90 0.00 114 5/11/2012 1.82 0.00 109 5/12/2012 1.77 0.00 106 5/13/2012 1.71 0.00 102 5/14/2012 1.67 0.00 100 131 5/26/2013 1.37 0.17 82 5/27/2013 1.57 0.33 95 5/28/2013 1.44 0.01 87 5/29/2013 1.54 0.40 93 5/30/2013 1.40 0.06 84 5/31/2013 1.33 0.01 80 6/1/2013 1.34 0.00 81 6/2/2013 1.32 0.00 80 6/3/2013 1.28 0.00 77 6/4/2013 1.23 0.00 74 6/5/2013 1.23 0.00 74 6/6/2013 1.20 0.00 73 6/7/2013 1.17 0.00 70 81 4/5/2014 2.28 0.20 137 4/6/2014 2.20 0.03 132 4/7/2014 2.09 0.00 126 4/8/2014 2.04 0.13 123 4/9/2014 1.94 0.00 116 4/10/2014 1.86 0.00 112 4/11/2014 1.82 0.00 110 4/12/2014 1.75 0.00 105 4/13/2014 1.73 0.00 104 4/14/2014 1.66 0.00 100 4/15/2014 1.52 0.00 92 114 Infiltration and Inflow Projects Completed Inflow and Infiltration projects 2016/2019 • Structure coating with Raven 405 o Asset # MH-I11-26 o Asset # MH-O13-02 o Asset # WW-O13-03 o Asset # MH-P13-01 o Asset # WW-M12-22 o Asset # MH-M12-14 • Spot repairs using CIPP sleeves. o Asset # 6233 o Asset # 6173 o Asset # 5558 o Asset # 6396 o Asset # 6694 (2 spot repairs on same line) o Asset # 6467 o Asset # 5564 (2 spot repairs on same line) o Asset # 6203 (2 spot repairs on same line) • Lines cleaned and camera to verify condition and prioritize for repair. o 89,716 feet of mainline. o Additional 50,000 feet of mainline cleaned. • CIPP project o Asset # 5827 o Asset # 5900 • Pipe Bursting project to reduce I&I. o 2018 Asset # 5987 Asset # 5986 Asset # 6130 Asset # 6672 Asset # 6554 o 2019 Asset # 5985 Asset # 5988 Asset # 5990 Asset # 5991 Asset # 6356 Asset # 6131 Asset # 6284 Asset # 6128 • Inflow protectors installed in the system o 87 total inflow protectors • Ergo sealing manhole lids and frames o 27 installed in system along with along with 36 installed by contractors. o City changed its developer guidelines to only allow EJ ergo sealing lids or equivalent within its sewer system to cut down on Infiltration at the lid and frame, also wrapped seal is used to cover all joints and chimney on the manholes during installation • Coating of manholes during new construction with Ravens 405 o Another 10 manholes have been coated by contractors in the system. • Smoke testing. o South Tower pump station and its gravity system were smoke tested to determine high flow’s during rain events. o Salzer valley pump station and its gravity system were smoke tested to find inflow from removed clean outs and broken lines inside the Cherry Blossom Trailer park. Appendix E Existing Load Analysis WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 1/1/2011 2.581 3.31 6.9 13 100 2663 82 2177 5 1/2/2011 2.495 3.33 6.8 13 100 2663 82 2177 4 1/3/2011 2.322 3.36 6.9 13 100 2663 82 2177 4 1/4/2011 2.184 3.37 6.9 13 161 104 2939 2684 135 86 2458 2199 4 1/5/2011 2.351 3.40 6.8 13 134 107 2631 2680 117 88 2294 2206 4 1/6/2011 2.506 3.42 6.9 13 131 102 2747 2666 106 84 2216 2192 4 1/7/2011 2.960 3.44 6.9 13 98 2649 80 2160 4 1/8/2011 2.836 3.43 6.9 13 98 2656 79 2136 5 1/9/2011 2.608 3.42 7.0 13 98 2656 79 2136 4 1/10/2011 2.424 3.36 6.8 13 98 2656 79 2136 5 1/11/2011 2.360 3.25 6.8 13 142 102 2797 2667 121 82 2382 2154 5 1/12/2011 3.475 3.19 6.8 13 103 102 2984 2689 102 84 2956 2212 5 1/13/2011 4.805 3.16 6.7 12 57 102 2282 2691 55 84 2204 2212 6 1/14/2011 4.625 3.15 6.6 12 106 2731 87 2234 6 1/15/2011 5.221 3.18 6.9 13 110 2768 90 2262 3 1/16/2011 6.404 3.25 6.0 12 110 2768 90 2262 6 1/17/2011 6.110 3.31 6.5 12 110 2768 90 2262 7 1/18/2011 5.285 3.36 6.5 12 64 106 2841 2774 60 88 2645 2291 5 1/19/2011 5.004 3.42 6.6 12 53 103 2201 2719 41 84 1711 2234 6 1/20/2011 4.652 3.47 6.7 12 56 99 2175 2686 45 82 1746 2214 4 1/21/2011 4.513 3.53 6.8 12 99 2708 82 2237 4 1/22/2011 4.218 3.58 6.7 13 99 2708 82 2237 6 1/23/2011 3.962 3.63 6.9 13 99 2708 82 2237 4 1/24/2011 3.615 3.66 6.6 13 99 2708 82 2237 4 1/25/2011 3.225 3.67 6.8 13 86 98 2308 2677 85 82 2286 2241 5 1/26/2011 3.002 3.64 6.4 13 85 97 2136 2625 82 83 2053 2215 4 1/27/2011 2.827 3.60 6.8 13 102 97 2397 2537 86 85 2028 2226 5 1/28/2011 2.657 3.58 6.9 13 98 2537 86 2248 5 1/29/2011 2.555 3.56 6.8 13 98 2537 86 2248 4 1/30/2011 2.408 3.54 6.7 13 98 2537 86 2248 4 1/31/2011 2.299 3.53 6.7 12 98 2537 86 2248 5 2/1/2011 2.202 3.52 6.8 12 136 101 2499 2534 114 88 2094 2236 4 2/2/2011 2.090 3.51 6.9 13 145 104 2535 2534 125 91 2179 2232 4 2/3/2011 2.015 3.51 6.9 13 151 103 2533 2505 121 90 2033 2202 4 2/4/2011 2.104 3.50 6.9 13 101 2495 88 2195 4 2/5/2011 2.035 3.48 6.9 14 98 2474 86 2193 4 2/6/2011 2.071 3.45 6.9 14 98 2474 86 2193 3 2/7/2011 2.137 3.43 6.8 13 98 2474 86 2193 4 2/8/2011 2.058 3.41 6.9 13 162 103 2773 2497 128 90 2197 2193 4 2/9/2011 1.971 3.40 6.9 13 159 107 2613 2505 131 93 2153 2191 4 2/10/2011 1.921 3.38 6.9 13 189 111 3025 2522 131 93 2099 2170 4 2/11/2011 1.874 3.33 6.8 13 111 2486 93 2110 4 2/12/2011 1.960 3.23 6.9 14 116 2503 96 2102 4 2/13/2011 1.995 3.15 6.8 14 116 2503 96 2102 4 2/14/2011 2.395 3.05 6.9 13 116 2503 96 2102 4 2/15/2011 2.597 2.93 6.8 13 129 117 2784 2525 105 96 2275 2115 5 2/16/2011 2.423 2.80 6.7 13 119 117 2403 2516 95 96 1919 2101 5 2/17/2011 2.257 2.70 6.8 13 138 122 2588 2498 98 99 1845 2044 5 2/18/2011 2.104 2.60 6.9 13 127 2521 104 2070 4 2/19/2011 2.022 2.52 7.1 13 133 2550 108 2097 4 2/20/2011 1.892 2.43 6.8 13 133 2550 108 2097 4 2/21/2011 1.888 2.35 6.8 13 133 2550 108 2097 4 2/22/2011 1.850 2.28 7.0 13 205 139 3159 2596 158 112 2437 2123 4 2/23/2011 1.982 2.23 7.0 13 169 141 2785 2610 132 114 2181 2127 4 2/24/2011 1.960 2.19 7.0 13 174 147 2844 2648 133 117 2174 2119 4 2/25/2011 1.924 2.15 6.9 13 152 2688 120 2124 4 2/26/2011 1.832 2.12 6.9 13 156 2712 123 2132 4 2/27/2011 2.539 2.11 7.0 13 156 2712 123 2132 4 2/28/2011 3.776 2.15 6.7 12 156 2712 123 2132 6 3/1/2011 3.683 2.20 6.7 12 95 151 2906 2727 69 118 2120 2131 7 3/2/2011 3.476 2.23 6.8 12 87 147 2511 2711 74 115 2145 2132 5 3/3/2011 3.255 2.27 6.8 12 90 143 2431 2707 79 113 2145 2136 5 3/4/2011 3.083 2.30 6.7 12 143 2720 112 2132 4 3/5/2011 2.898 2.33 6.8 12 143 2735 111 2141 4 3/6/2011 2.764 2.35 6.8 12 143 2735 111 2141 5 3/7/2011 2.574 2.37 6.6 13 143 2735 111 2141 4 3/8/2011 2.431 2.38 6.8 13 133 142 2695 2732 102 110 2068 2135 5 3/9/2011 3.852 2.44 6.9 12 99 139 3182 2764 113 111 3630 2242 5 3/10/2011 5.665 2.56 6.6 11 62 132 2952 2777 58 106 2740 2281 6 3/11/2011 5.193 2.67 6.6 12 130 2790 104 2291 6 3/12/2011 4.861 2.77 6.7 12 125 2770 101 2307 6 3/13/2011 4.856 2.87 6.6 12 125 2770 101 2307 5 3/14/2011 4.752 2.96 6.6 12 125 2770 101 2307 6 3/15/2011 5.289 3.07 6.6 12 60 120 2634 2760 59 98 2602 2329 6 3/16/2011 5.159 3.16 6.6 12 60 116 2587 2747 57 95 2453 2338 5 3/17/2011 4.923 3.24 6.6 12 58 110 2381 2719 51 91 2094 2325 5 3/18/2011 4.635 3.31 6.7 12 110 2743 91 2356 5 3/19/2011 4.366 3.38 6.6 12 108 2756 90 2399 6 3/20/2011 4.120 3.45 6.7 12 108 2756 90 2399 4 10/12/2016 Page 1 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 3/21/2011 3.592 3.50 6.7 12 108 2756 90 2399 5 3/22/2011 3.209 3.55 6.8 13 96 107 2575 2742 80 90 2141 2379 4 3/23/2011 3.021 3.58 6.7 13 104 107 2633 2734 89 90 2243 2370 6 3/24/2011 2.999 3.62 6.7 13 135 101 3365 2749 117 87 2926 2404 4 3/25/2011 2.781 3.65 6.8 13 96 2746 83 2422 4 3/26/2011 2.725 3.67 6.8 13 90 2738 79 2442 4 3/27/2011 2.626 3.70 6.9 13 90 2738 79 2442 3 3/28/2011 2.542 3.72 6.8 13 90 2738 79 2442 4 3/29/2011 2.701 3.73 6.8 13 128 93 2874 2748 127 83 2861 2474 5 3/30/2011 3.178 3.71 6.7 13 101 93 2670 2743 89 83 2359 2466 5 3/31/2011 3.652 3.71 6.8 13 86 93 2623 2722 70 83 2132 2467 5 4/1/2011 3.521 3.71 6.7 13 93 2739 84 2492 5 4/2/2011 3.153 3.70 6.8 13 93 2764 84 2521 5 4/3/2011 2.870 3.70 6.8 13 93 2764 84 2521 4 4/4/2011 3.375 3.71 6.7 13 93 2764 84 2521 4 4/5/2011 3.598 3.74 6.8 13 68 92 2027 2708 70 83 2100 2488 4 4/6/2011 3.898 3.78 6.7 12 69 90 2236 2674 60 82 1951 2450 5 4/7/2011 3.632 3.82 6.6 13 79 86 2402 2653 60 79 1817 2432 6 4/8/2011 3.311 3.81 6.7 13 85 2612 76 2340 5 4/9/2011 3.031 3.72 6.8 13 87 2584 77 2307 4 4/10/2011 2.805 3.64 7.0 13 87 2584 77 2307 4 4/11/2011 2.640 3.57 6.8 13 87 2584 77 2307 4 4/12/2011 2.522 3.49 6.8 13 122 90 2569 2583 102 79 2146 2294 4 4/13/2011 2.423 3.41 6.8 13 124 92 2499 2577 105 81 2122 2282 5 4/14/2011 2.981 3.33 6.8 13 112 96 2796 2588 108 85 2685 2288 5 4/15/2011 3.298 3.27 6.7 13 99 2588 87 2275 6 4/16/2011 3.105 3.21 6.8 13 102 2606 90 2290 6 4/17/2011 2.892 3.15 6.9 13 102 2606 90 2290 6 4/18/2011 2.677 3.10 6.8 13 102 2606 90 2290 5 4/19/2011 2.457 3.04 6.8 13 130 104 2669 2611 102 91 2090 2275 5 4/20/2011 2.325 3.00 6.7 14 142 107 2754 2621 115 92 2230 2272 5 4/21/2011 2.165 2.96 6.8 14 148 111 2673 2628 115 95 2076 2267 5 4/22/2011 2.098 2.93 6.9 14 111 2628 95 2269 4 4/23/2011 2.056 2.90 6.8 14 109 2566 94 2214 4 4/24/2011 2.011 2.88 6.8 14 109 2566 94 2214 4 4/25/2011 2.297 2.86 6.8 14 109 2566 94 2214 4 4/26/2011 2.110 2.84 6.7 14 176 114 3102 2607 153 98 2692 2251 4 4/27/2011 2.229 2.83 6.8 14 134 116 2484 2599 119 100 2212 2248 5 4/28/2011 2.320 2.82 6.8 14 159 118 3076 2613 135 100 2612 2230 5 4/29/2011 2.154 2.79 6.8 14 119 2609 101 2220 5 4/30/2011 2.059 2.73 6.8 14 122 2607 104 2228 4 5/1/2011 1.992 2.68 6.9 14 122 2607 104 2228 4 5/2/2011 1.880 2.64 6.7 14 122 2607 104 2228 4 5/3/2011 2.073 2.61 6.8 14 189 127 3268 2658 163 108 2818 2273 4 5/4/2011 1.801 2.56 6.8 15 212 133 3179 2695 164 112 2463 2287 5 5/5/2011 1.876 2.50 6.7 14 185 142 2890 2757 150 118 2347 2304 4 5/6/2011 1.895 2.44 6.8 15 147 2797 122 2332 3 5/7/2011 1.952 2.38 7.0 15 153 2830 128 2374 4 5/8/2011 1.888 2.33 7.0 15 153 2830 128 2374 5 5/9/2011 2.042 2.30 6.8 15 153 2830 128 2374 4 5/10/2011 1.733 2.26 6.9 15 188 155 2711 2821 153 130 2211 2362 4 5/11/2011 2.060 2.25 6.8 15 143 155 2457 2795 138 130 2371 2363 4 5/12/2011 1.966 2.23 6.8 15 164 158 2681 2803 129 132 2115 2360 5 5/13/2011 1.881 2.21 6.9 15 160 2826 134 2379 3 5/14/2011 1.975 2.18 6.8 15 164 2829 136 2353 4 5/15/2011 2.862 2.16 6.9 14 164 2829 136 2353 5 5/16/2011 2.519 2.14 6.7 14 164 2829 136 2353 4 5/17/2011 2.302 2.12 6.8 15 128 161 2454 2800 126 136 2419 2358 4 5/18/2011 2.087 2.10 6.8 15 139 160 2411 2772 120 134 2088 2339 4 5/19/2011 1.949 2.09 6.8 15 164 162 2668 2772 139 137 2259 2351 4 5/20/2011 1.809 2.07 6.8 15 164 2774 139 2360 4 5/21/2011 1.753 2.05 6.8 15 165 2782 141 2384 3 5/22/2011 1.702 2.04 6.9 15 165 2782 141 2384 3 5/23/2011 1.664 2.03 6.9 15 165 2782 141 2384 3 5/24/2011 1.600 2.01 6.9 16 197 167 2634 2771 166 143 2214 2371 4 5/25/2011 1.620 1.99 7.1 15 193 169 2610 2759 155 144 2094 2351 4 5/26/2011 1.537 1.97 6.9 16 130 166 1666 2657 164 144 2102 2309 3 5/27/2011 1.514 1.95 7.0 16 168 2670 146 2316 4 5/28/2011 1.466 1.92 7.1 16 169 2636 147 2292 3 5/29/2011 1.432 1.90 6.9 16 169 2636 147 2292 3 5/30/2011 1.484 1.88 7.1 16 169 2636 147 2292 3 5/31/2011 1.493 1.86 7.0 16 233 174 2906 2657 180 150 2242 2288 3 6/1/2011 1.422 1.85 7.1 16 218 177 2588 2652 171 151 2027 2269 4 6/2/2011 1.430 1.82 7.1 16 255 182 3039 2636 187 153 2231 2227 4 6/3/2011 1.393 1.81 7.1 16 180 2594 152 2209 4 6/4/2011 1.389 1.79 7.2 17 179 2569 152 2198 3 6/5/2011 1.368 1.78 7.0 17 179 2569 152 2198 3 6/6/2011 1.334 1.76 7.1 17 179 2569 152 2198 3 6/7/2011 1.269 1.74 7.0 17 257 185 2718 2580 179 154 1894 2174 3 10/12/2016 Page 2 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 6/8/2011 1.299 1.71 7.0 17 234 189 2540 2578 179 156 1939 2158 3 6/9/2011 1.302 1.70 7.0 17 275 195 2984 2597 195 159 2118 2151 2 6/10/2011 1.280 1.67 7.0 17 199 2608 161 2134 3 6/11/2011 1.274 1.65 7.1 17 202 2602 163 2136 7 6/12/2011 1.272 1.63 7.0 17 202 2602 163 2136 3 6/13/2011 1.271 1.60 6.9 17 202 2602 163 2136 2 6/14/2011 1.238 1.55 7.0 17 252 206 2606 2602 202 166 2085 2132 3 6/15/2011 1.235 1.51 6.9 17 211 206 2175 2572 181 167 1865 2113 2 6/16/2011 1.199 1.47 7.0 17 277 217 2774 2594 187 172 1871 2074 2 6/17/2011 1.177 1.44 7.0 18 223 2609 176 2072 3 6/18/2011 1.225 1.42 6.8 18 228 2604 179 2057 3 6/19/2011 1.208 1.40 6.9 18 228 2604 179 2057 3 6/20/2011 1.214 1.38 7.0 18 228 2604 179 2057 3 6/21/2011 1.185 1.36 7.0 18 269 231 2662 2608 203 181 2006 2053 3 6/22/2011 1.175 1.34 6.9 18 268 234 2628 2609 209 183 2049 2053 2 6/23/2011 1.159 1.33 6.9 18 299 241 2887 2628 210 186 2030 2039 2 6/24/2011 1.159 1.31 7.0 18 245 2629 188 2035 2 6/25/2011 1.167 1.30 7.0 18 254 2709 190 2030 3 6/26/2011 1.134 1.29 7.0 18 254 2709 190 2030 3 6/27/2011 1.135 1.28 6.9 18 254 2709 190 2030 3 6/28/2011 1.126 1.27 7.1 18 286 257 2685 2707 215 192 2019 2029 2 6/29/2011 1.117 1.26 7.1 18 285 259 2653 2703 218 194 2031 2029 2 6/30/2011 1.120 1.24 7.0 18 290 263 2711 2689 185 194 1728 1992 2 7/1/2011 1.107 1.23 7.0 19 266 2697 196 1990 2 7/2/2011 1.091 1.22 7.0 19 267 2669 197 1969 3 7/3/2011 1.049 1.21 6.9 19 267 2669 197 1969 3 7/4/2011 1.042 1.20 7.0 19 267 2669 197 1969 3 7/5/2011 1.052 1.19 6.7 19 320 271 2804 2679 257 202 2255 1991 3 7/6/2011 1.069 1.18 7.0 19 291 273 2595 2673 217 203 1934 1987 3 7/7/2011 1.075 1.17 6.9 19 302 276 2704 2672 219 206 1963 1992 3 7/8/2011 1.044 1.16 7.0 19 279 2682 208 1996 2 7/9/2011 1.087 1.16 7.0 19 279 2657 209 1986 3 7/10/2011 1.075 1.15 6.8 20 279 2657 209 1986 3 7/11/2011 1.067 1.14 6.9 20 279 2657 209 1986 3 7/12/2011 1.077 1.14 7.0 19 305 281 2740 2663 248 212 2228 2005 2 7/13/2011 1.114 1.13 7.0 19 311 283 2888 2679 239 214 2221 2020 2 7/14/2011 1.051 1.12 7.0 19 334 289 2926 2702 262 218 2297 2035 2 7/15/2011 1.144 1.12 6.7 19 295 2743 221 2049 3 7/16/2011 1.155 1.12 7.0 19 297 2740 224 2063 3 7/17/2011 1.112 1.12 6.8 19 297 2740 224 2063 3 7/18/2011 1.096 1.11 6.9 20 297 2740 224 2063 3 7/19/2011 1.064 1.11 7.0 19 307 297 2724 2739 241 225 2139 2069 2 7/20/2011 1.064 1.10 6.9 20 334 300 2961 2755 306 231 2716 2115 2 7/21/2011 1.068 1.10 6.9 19 340 305 3029 2781 248 234 2209 2130 2 7/22/2011 1.051 1.10 7.0 19 308 2793 236 2136 2 7/23/2011 1.031 1.09 6.9 20 309 2785 238 2145 3 7/24/2011 1.042 1.09 6.7 20 309 2785 238 2145 1 7/25/2011 1.072 1.08 7.1 20 309 2785 238 2145 2 7/26/2011 1.066 1.08 6.9 20 271 306 2412 2756 266 240 2365 2162 2 7/27/2011 1.049 1.08 7.1 20 279 304 2446 2734 213 238 1864 2141 2 7/28/2011 1.038 1.08 6.9 20 277 303 2393 2713 207 238 1791 2124 2 7/29/2011 1.015 1.07 7.2 20 305 2718 239 2132 3 7/30/2011 0.996 1.07 6.9 20 306 2718 244 2165 3 7/31/2011 1.004 1.07 7.0 20 306 2718 244 2165 3 8/1/2011 1.024 1.06 7.1 20 306 2718 244 2165 2 8/2/2011 1.023 1.06 6.9 21 329 308 2804 2725 271 246 2312 2177 2 8/3/2011 1.010 1.06 7.0 21 304 307 2555 2713 237 245 1995 2164 2 8/4/2011 1.035 1.06 6.9 21 291 305 2507 2692 217 242 1872 2136 1 8/5/2011 1.019 1.06 7.0 20 306 2699 244 2152 2 8/6/2011 1.002 1.06 7.1 21 307 2699 246 2168 2 8/7/2011 1.016 1.06 7.1 21 307 2699 246 2168 2 8/8/2011 1.008 1.05 7.1 21 307 2699 246 2168 2 8/9/2011 1.006 1.05 7.3 21 312 307 2617 2692 233 245 1956 2151 1 8/10/2011 1.022 1.05 7.0 21 313 308 2672 2691 251 246 2140 2150 1 8/11/2011 1.041 1.05 6.8 21 299 307 2595 2681 239 245 2074 2139 2 8/12/2011 1.030 1.05 7.1 21 307 2665 245 2133 3 8/13/2011 1.033 1.04 7.0 21 305 2643 244 2120 2 8/14/2011 1.018 1.04 7.1 21 305 2643 244 2120 4 8/15/2011 1.050 1.04 7.0 21 305 2643 244 2120 2 8/16/2011 1.033 1.03 7.0 21 317 305 2728 2649 239 244 2059 2115 2 8/17/2011 1.022 1.03 6.9 21 294 305 2507 2639 241 244 2054 2111 2 8/18/2011 1.042 1.03 6.7 21 299 304 2600 2630 232 243 2016 2102 2 8/19/2011 1.063 1.03 6.9 21 302 2605 238 2054 2 8/20/2011 1.004 1.03 7.1 21 299 2570 237 2042 2 8/21/2011 1.035 1.03 7.1 21 299 2570 237 2042 3 8/22/2011 1.015 1.03 6.9 21 299 2570 237 2042 2 8/23/2011 0.966 1.03 7.1 21 337 302 2715 2581 262 239 2112 2047 1 8/24/2011 0.993 1.02 6.6 22 359 306 2970 2609 336 246 2783 2099 2 8/25/2011 0.991 1.02 7.2 22 318 309 2627 2624 283 247 2339 2098 1 10/12/2016 Page 3 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 8/26/2011 0.966 1.02 7.2 22 311 2638 250 2116 4 8/27/2011 0.991 1.02 6.7 22 314 2658 253 2143 2 8/28/2011 0.996 1.02 7.0 21 314 2658 253 2143 2 8/29/2011 0.984 1.01 6.9 21 314 2658 253 2143 2 8/30/2011 0.946 1.01 7.2 21 309 314 2438 2641 256 254 2021 2133 1 8/31/2011 0.993 1.01 6.9 21 299 313 2475 2629 252 254 2087 2130 2 9/1/2011 0.966 1.01 6.9 21 314 312 2528 2610 262 253 2112 2116 2 9/2/2011 0.969 1.01 6.8 21 312 2614 254 2125 2 9/3/2011 0.917 1.00 6.9 21 314 2623 257 2146 2 9/4/2011 0.911 1.00 7.1 21 314 2623 257 2146 4 9/5/2011 1.037 1.00 7.0 21 314 2623 257 2146 2 9/6/2011 0.970 1.00 6.8 21 257 310 2082 2581 250 257 2022 2136 1 9/7/2011 0.953 1.00 7.0 22 268 307 2128 2549 256 257 2035 2129 2 9/8/2011 0.966 1.00 6.9 22 286 305 2302 2526 235 257 1893 2125 2 9/9/2011 0.941 0.99 7.0 22 304 2515 257 2123 2 9/10/2011 0.938 0.99 7.1 22 305 2508 259 2128 4 9/11/2011 0.987 0.99 7.0 22 305 2508 259 2128 2 9/12/2011 0.799 0.98 6.8 21 305 2508 259 2128 2 9/13/2011 0.960 0.98 6.7 21 324 306 2593 2515 279 260 2234 2136 2 9/14/2011 0.941 0.98 6.8 21 221 300 1736 2459 271 261 2127 2135 1 9/15/2011 0.949 0.97 6.9 21 266 296 2104 2415 217 259 1718 2111 2 9/16/2011 0.974 0.97 6.8 21 297 2408 261 2115 2 9/17/2011 1.017 0.97 7.0 20 296 2392 263 2123 2 9/18/2011 1.049 0.97 6.9 21 296 2392 263 2123 2 9/19/2011 0.997 0.97 6.9 21 296 2392 263 2123 3 9/20/2011 0.961 0.97 6.9 21 298 297 2390 2391 222 260 1779 2097 1 9/21/2011 0.936 0.97 7.0 21 289 296 2253 2382 222 257 1732 2071 3 9/22/2011 0.943 0.96 6.8 21 305 294 2399 2359 239 256 1880 2054 2 9/23/2011 0.981 0.96 6.7 21 289 2312 250 1998 2 9/24/2011 0.999 0.96 6.9 21 286 2286 247 1970 2 9/25/2011 1.019 0.97 6.9 21 286 2286 247 1970 3 9/26/2011 1.063 0.97 6.9 20 286 2286 247 1970 3 9/27/2011 0.968 0.97 6.9 20 369 293 2977 2339 307 251 2479 2009 2 9/28/2011 0.990 0.97 6.9 20 312 294 2577 2356 245 251 2023 2010 1 9/29/2011 0.962 0.97 7.0 21 342 296 2747 2378 271 252 2175 2021 2 9/30/2011 0.971 0.97 7.0 20 296 2371 252 2016 1 10/1/2011 0.990 0.97 7.0 20 295 2357 251 2008 1 10/2/2011 1.012 0.97 7.0 20 295 2357 251 2008 2 10/3/2011 0.996 0.97 7.0 20 295 2357 251 2008 2 10/4/2011 1.014 0.98 6.8 20 326 297 2759 2388 224 249 1895 1999 1 10/5/2011 1.052 0.98 6.9 20 287 296 2515 2397 225 247 1974 1998 2 10/6/2011 0.968 0.98 6.8 20 306 300 2468 2425 243 247 1962 1993 2 10/7/2011 0.964 0.98 6.9 20 302 2448 246 1990 2 10/8/2011 1.018 0.98 6.7 20 304 2460 247 1998 2 10/9/2011 1.041 0.98 6.8 19 304 2460 247 1998 2 10/10/2011 1.152 0.99 6.9 20 304 2460 247 1998 2 10/11/2011 1.198 1.00 6.9 19 346 307 3462 2537 337 254 3368 2104 3 10/12/2011 1.039 1.00 7.0 19 353 310 3060 2574 365 262 3164 2179 3 10/13/2011 0.999 1.01 7.5 19 335 311 2792 2589 269 261 2241 2180 3 10/14/2011 1.018 1.01 6.9 20 318 2654 260 2184 2 10/15/2011 0.989 1.01 7.0 19 322 2700 264 2223 2 10/16/2011 1.020 1.01 6.9 19 322 2700 264 2223 2 10/17/2011 0.934 1.01 7.1 19 322 2700 264 2223 3 10/18/2011 0.947 1.00 6.9 19 472 334 3732 2779 502 282 3967 2357 2 10/19/2011 0.820 1.00 6.9 19 335 334 2291 2744 317 285 2168 2343 2 10/20/2011 0.923 1.00 6.9 19 432 344 3324 2811 425 299 3270 2450 3 10/21/2011 0.950 1.00 6.9 19 348 2854 305 2505 2 10/22/2011 1.074 1.00 7.1 19 351 2892 311 2557 4 10/23/2011 1.000 1.00 6.9 19 351 2892 311 2557 3 10/24/2011 1.00 6.9 351 2892 311 2557 2 10/25/2011 1.00 6.9 577 369 2892 372 316 2557 2 10/26/2011 0.929 1.00 6.9 19 383 370 2965 2898 432 324 3346 2618 2 10/27/2011 0.914 1.00 7.0 19 389 371 2966 2897 398 330 3034 2661 2 10/28/2011 1.020 1.00 6.9 19 376 2924 337 2714 2 10/29/2011 1.022 1.00 6.9 19 378 2940 342 2763 3 10/30/2011 1.026 1.00 7.2 19 378 2940 342 2763 4 10/31/2011 0.933 1.00 7.0 19 378 2940 342 2763 3 11/1/2011 0.964 1.00 7.0 18 520 389 4183 3043 502 355 4037 2869 2 11/2/2011 1.049 1.00 6.9 18 348 386 3046 3043 336 353 2938 2874 2 11/3/2011 1.015 1.00 7.1 18 400 392 3385 3092 360 363 3047 2963 2 11/4/2011 1.017 1.00 7.0 18 400 3140 374 3045 2 11/5/2011 1.066 1.00 6.9 18 408 3201 385 3144 2 11/6/2011 1.073 1.01 7.1 18 408 3201 385 3144 3 11/7/2011 1.062 1.01 7.0 18 454 411 4018 3269 502 394 4446 3252 2 11/8/2011 1.013 1.01 7.0 17 361 408 3054 3252 456 398 3853 3298 2 11/9/2011 1.037 1.00 7.1 18 638 423 5513 3414 556 409 4808 3406 3 11/10/2011 0.988 0.99 7.1 18 428 3410 414 3409 2 11/11/2011 1.108 1.00 7.2 17 434 3439 417 3430 2 11/12/2011 1.133 1.00 7.1 17 442 3498 430 3538 3 10/12/2016 Page 4 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 11/13/2011 1.187 1.01 7.1 17 442 3498 430 3538 2 11/14/2011 1.170 1.01 7.1 17 442 3498 430 3538 3 11/15/2011 1.157 1.02 7.1 17 389 438 3755 3519 471 433 4545 3622 3 11/16/2011 1.328 1.03 7.2 17 227 423 2516 3442 255 420 2824 3560 4 11/17/2011 1.438 1.05 7.1 16 226 406 2705 3363 256 403 3070 3491 3 11/18/2011 1.342 1.07 7.0 16 411 3453 409 3601 3 11/19/2011 1.290 1.08 8.2 16 409 3464 408 3632 3 11/20/2011 1.246 1.09 7.3 16 409 3464 408 3632 3 11/21/2011 1.487 1.11 7.2 16 224 395 2779 3407 304 400 3771 3643 3 11/22/2011 4.267 1.22 7.1 15 102 374 3618 3423 158 383 5623 3796 2 11/23/2011 4.451 1.34 6.7 14 81 355 3005 3394 91 363 3360 3764 8 11/24/2011 3.227 1.40 6.8 14 339 3394 363 3764 8 11/25/2011 2.560 1.45 6.8 15 335 3427 357 3797 6 11/26/2011 2.100 1.49 6.9 15 331 3465 354 3860 4 11/27/2011 2.173 1.53 7.0 15 331 3465 354 3860 5 11/28/2011 1.921 1.56 7.0 15 331 3465 354 3860 4 11/29/2011 1.762 1.59 7.1 15 169 318 2481 3389 182 341 2675 3769 4 11/30/2011 1.646 1.61 7.1 15 172 308 2360 3316 189 330 2595 3685 4 12/1/2011 1.516 1.63 7.2 15 178 283 2255 3178 189 307 2389 3567 4 12/2/2011 1.503 1.64 6.9 15 278 3188 305 3616 4 12/3/2011 1.395 1.66 7.1 15 268 3172 301 3663 5 12/4/2011 1.436 1.67 7.2 15 268 3172 301 3663 4 12/5/2011 1.388 1.68 7.0 15 268 3172 301 3663 3 12/6/2011 1.328 1.69 7.1 15 170 261 1880 3072 232 295 2564 3579 4 12/7/2011 1.268 1.70 7.0 15 218 243 2303 2940 212 273 2242 3409 3 12/8/2011 1.283 1.70 7.0 15 221 232 2360 2887 234 256 2498 3305 5 12/9/2011 1.275 1.71 6.9 15 198 2668 231 3180 4 12/10/2011 1.203 1.72 7.2 15 198 2668 231 3180 7 12/11/2011 1.228 1.72 7.1 15 198 2668 231 3180 4 12/12/2011 1.242 1.73 7.1 15 198 2668 231 3180 4 12/13/2011 1.181 1.73 7.1 14 257 203 2532 2658 262 233 2575 3133 4 12/14/2011 1.174 1.73 6.9 15 260 207 2544 2649 298 238 2918 3118 3 12/15/2011 1.147 1.73 6.7 14 258 197 2468 2558 245 222 2339 2960 4 12/16/2011 1.173 1.72 6.9 15 195 2561 219 2971 4 12/17/2011 1.226 1.71 7.0 15 192 2549 216 2962 4 12/18/2011 1.171 1.71 7.0 15 192 2549 216 2962 4 12/19/2011 1.174 1.71 7.0 15 192 2549 216 2962 4 12/20/2011 1.167 1.70 6.9 15 245 196 2387 2536 281 221 2731 2945 4 12/21/2011 1.156 1.69 6.9 14 229 197 2211 2493 240 216 2310 2832 4 12/22/2011 1.145 1.59 6.8 14 289 211 2755 2426 270 225 2578 2598 4 12/23/2011 1.193 1.48 7.0 15 222 2378 236 2534 5 12/24/2011 1.143 1.41 7.0 15 222 2378 236 2534 6 12/25/2011 1.026 1.36 7.0 14 222 2378 236 2534 5 12/26/2011 1.187 1.33 7.2 14 222 2378 236 2534 6 12/27/2011 1.435 1.30 7.1 14 213 221 2548 2391 282 239 3369 2599 4 12/28/2011 2.364 1.32 7.1 14 161 217 3179 2447 217 238 4268 2718 4 12/29/2011 2.757 1.35 6.9 13 109 213 2503 2449 124 234 2851 2731 4 12/30/2011 2.722 1.39 6.9 13 216 2456 237 2741 6 12/31/2011 2.121 1.41 7.0 13 219 2473 241 2770 5 1/1/2012 1.834 1.42 7.0 13 219 2473 241 2770 5 1/2/2012 1.775 1.43 7.0 14 219 2473 241 2770 5 1/3/2012 1.594 1.44 7.0 14 173 215 2294 2459 219 239 2905 2781 4 1/4/2012 1.679 1.45 7.1 14 170 212 2387 2454 209 237 2920 2791 4 1/5/2012 1.714 1.46 7.1 14 192 214 2743 2515 209 236 2987 2821 4 1/6/2012 1.628 1.47 6.9 14 214 2532 237 2865 4 1/7/2012 1.575 1.48 7.2 14 213 2546 238 2896 5 1/8/2012 1.558 1.49 7.1 14 213 2546 238 2896 4 1/9/2012 1.464 1.50 7.0 14 213 2546 238 2896 4 1/10/2012 1.437 1.51 7.0 14 195 212 2338 2530 215 236 2577 2871 3 1/11/2012 1.394 1.51 7.1 14 215 212 2495 2527 262 238 3046 2884 4 1/12/2012 1.372 1.52 7.1 14 226 210 2586 2531 244 237 2786 2899 4 1/13/2012 1.327 1.52 7.1 14 206 2530 232 2897 3 1/14/2012 1.360 1.53 7.0 13 201 2536 231 2944 4 1/15/2012 1.356 1.54 7.0 13 201 2536 231 2944 4 1/16/2012 1.361 1.54 7.3 13 201 2536 231 2944 4 1/17/2012 1.569 1.55 7.2 13 195 201 2548 2537 214 229 2794 2932 4 1/18/2012 1.573 1.57 7.2 13 175 199 2294 2519 188 226 2460 2899 4 1/19/2012 2.937 1.63 7.2 12 205 196 5019 2707 267 225 6540 3171 5 1/20/2012 4.428 1.73 6.9 12 194 2745 224 3237 6 1/21/2012 5.242 1.87 6.7 11 186 2745 221 3292 8 1/22/2012 4.765 1.99 6.7 12 186 2745 221 3292 8 1/23/2012 3.938 2.08 6.8 12 186 2745 221 3292 7 1/24/2012 4.130 2.19 6.8 12 89 178 3068 2769 110 212 3772 3329 6 1/25/2012 4.353 2.29 6.8 12 64 170 2310 2737 93 204 3376 3332 8 1/26/2012 3.922 2.38 6.8 12 75 160 2468 2731 95 190 3107 3314 7 1/27/2012 3.399 2.41 6.8 12 160 2696 188 3240 7 1/28/2012 3.021 2.42 6.7 12 164 2712 194 3273 6 1/29/2012 3.277 2.44 6.8 12 164 2712 194 3273 5 1/30/2012 3.425 2.48 6.8 12 164 2712 194 3273 6 10/12/2016 Page 5 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 1/31/2012 3.147 2.52 7.1 12 120 161 3144 2746 138 189 3622 3299 5 2/1/2012 2.870 2.56 6.9 12 115 158 2748 2746 135 185 3232 3295 5 2/2/2012 2.631 2.60 6.9 13 111 153 2439 2756 124 179 2720 3281 5 2/3/2012 2.433 2.62 6.9 13 152 2785 176 3309 6 2/4/2012 2.246 2.64 6.9 13 149 2788 174 3336 5 2/5/2012 2.117 2.65 7.0 13 149 2788 174 3336 5 2/6/2012 1.992 2.67 7.0 13 149 2788 174 3336 5 2/7/2012 1.856 2.68 6.9 13 252 157 3901 2874 265 181 4103 3395 4 2/8/2012 1.823 2.69 7.0 13 227 162 3445 2915 231 184 3511 3403 5 2/9/2012 1.927 2.71 7.0 14 263 166 4227 3050 268 188 4307 3527 4 2/10/2012 1.835 2.72 7.1 15 163 3092 182 3564 5 2/11/2012 1.773 2.73 7.2 13 157 3134 177 3629 5 2/12/2012 1.860 2.75 7.2 14 157 3134 177 3629 5 2/13/2012 1.865 2.77 7.1 13 157 3134 177 3629 5 2/14/2012 1.883 2.79 7.1 13 222 162 3487 3161 238 182 3738 3637 5 2/15/2012 1.769 2.80 7.1 13 227 167 3343 3174 244 186 3600 3635 5 2/16/2012 1.818 2.81 7.2 13 244 171 3699 3257 244 189 3699 3699 5 2/17/2012 1.945 2.82 7.2 13 170 3331 189 3795 4 2/18/2012 2.852 2.82 7.1 12 167 3190 182 3566 5 2/19/2012 2.704 2.76 6.9 12 167 3190 182 3566 5 2/20/2012 2.459 2.67 6.9 13 167 3190 182 3566 5 2/21/2012 2.945 2.61 7.0 12 175 168 4298 3275 202 184 4961 3673 6 2/22/2012 3.849 2.60 7.0 12 137 166 4403 3356 154 181 4943 3764 7 2/23/2012 3.552 2.58 6.9 12 131 169 3874 3413 176 186 5214 3867 7 2/24/2012 3.406 2.55 6.8 12 177 3498 193 3905 7 2/25/2012 3.637 2.54 6.9 13 185 3584 202 3971 6 2/26/2012 3.546 2.55 6.8 12 185 3584 202 3971 6 2/27/2012 3.273 2.56 6.8 12 185 3584 202 3971 6 2/28/2012 3.068 2.55 6.9 12 186 185 4757 3674 254 206 6499 4165 6 2/29/2012 3.763 2.56 7.0 12 151 183 4724 3749 196 205 6152 4307 6 3/1/2012 3.877 2.59 6.8 12 104 182 3351 3764 124 204 4009 4335 7 3/2/2012 3.494 2.61 6.9 12 187 3842 209 4420 8 3/3/2012 3.145 2.62 6.9 12 193 3959 216 4561 7 3/4/2012 2.913 2.64 6.8 14 193 3959 216 4561 5 3/5/2012 3.149 2.67 7.0 12 193 3959 216 4561 5 3/6/2012 2.800 2.69 6.9 12 147 190 3436 3919 190 214 4437 4552 6 3/7/2012 2.620 2.71 7.0 12 167 188 3644 3899 201 213 4392 4540 6 3/8/2012 2.611 2.74 7.0 12 236 187 5134 3987 305 216 6641 4722 5 3/9/2012 2.300 2.75 6.9 13 184 4029 215 4815 5 3/10/2012 2.319 2.77 6.9 13 177 4013 211 4857 5 3/11/2012 2.483 2.79 6.9 13 177 4013 211 4857 8 3/12/2012 3.238 2.84 7.0 12 177 4013 211 4857 6 3/13/2012 4.005 2.91 6.8 12 129 173 4305 4035 184 209 6147 4956 6 3/14/2012 4.549 3.00 6.8 12 161 172 6091 4182 241 211 9144 5255 7 3/15/2012 5.877 3.13 6.8 12 99 164 4841 4279 136 204 6665 5465 8 3/16/2012 6.045 3.27 6.7 11 159 4351 201 5608 8 3/17/2012 6.014 3.41 6.6 11 152 4405 197 5767 8 3/18/2012 5.562 3.54 6.8 12 152 4405 197 5767 5 3/19/2012 4.834 3.60 6.8 12 152 4405 197 5767 7 3/20/2012 4.560 3.66 6.8 12 116 149 4398 4404 173 195 6580 5830 6 3/21/2012 4.459 3.73 6.8 12 104 146 3882 4367 163 193 6062 5846 7 3/22/2012 4.317 3.78 6.8 12 141 143 5075 4423 178 191 6409 5950 7 3/23/2012 3.862 3.78 6.8 12 144 4424 194 6027 7 3/24/2012 3.592 3.78 6.6 12 145 4470 195 6095 6 3/25/2012 3.316 3.77 6.7 12 145 4470 195 6095 5 3/26/2012 3.050 3.75 6.8 13 145 4470 195 6095 6 3/27/2012 2.923 3.73 6.9 13 162 146 3937 4429 250 200 6095 6095 6 3/28/2012 3.006 3.73 7.0 13 165 148 4127 4407 210 200 5265 6035 6 3/29/2012 5.998 3.82 7.0 12 181 147 9044 4714 232 199 11606 6400 9 3/30/2012 6.585 3.92 6.7 12 147 4713 199 6419 8 3/31/2012 6.692 4.01 6.5 12 150 4826 205 6620 4 4/1/2012 6.095 4.10 6.4 12 150 4826 205 6620 8 4/2/2012 5.394 4.17 6.6 12 150 4826 205 6620 7 4/3/2012 4.833 4.24 6.8 12 102 147 4124 4772 126 199 5079 6502 7 4/4/2012 4.496 4.28 6.8 12 114 144 4285 4737 169 197 6336 6490 7 4/5/2012 4.216 4.33 6.7 12 142 144 4985 4848 167 195 5872 6592 7 4/6/2012 3.852 4.37 6.8 13 142 4941 195 6762 8 4/7/2012 3.596 4.40 6.7 13 135 4925 186 6772 6 4/8/2012 3.281 4.44 6.7 13 135 4925 186 6772 6 4/9/2012 3.082 4.46 6.8 13 135 4925 186 6772 5 4/10/2012 2.844 4.47 6.9 13 169 137 4013 4854 222 189 5265 6656 6 4/11/2012 2.990 4.46 6.9 13 167 139 4160 4805 250 193 6235 6626 6 4/12/2012 2.777 4.42 7.0 13 172 142 3984 4782 223 196 5165 6555 6 4/13/2012 2.553 4.36 7.1 13 141 4681 192 6356 5 4/14/2012 2.384 4.24 6.9 14 145 4668 197 6331 5 4/15/2012 2.351 4.12 6.9 14 145 4668 197 6331 5 4/16/2012 2.332 3.99 7.0 13 145 4668 197 6331 5 4/17/2012 2.208 3.88 6.9 13 71 139 1311 4410 229 199 4217 6168 5 4/18/2012 2.112 3.79 7.0 13 197 143 3463 4342 291 206 5126 6094 6 10/12/2016 Page 6 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 4/19/2012 2.702 3.73 7.1 13 218 150 4921 4379 265 213 5972 6050 6 4/20/2012 3.163 3.69 6.9 13 154 4418 216 6049 6 4/21/2012 2.989 3.64 6.8 13 155 4363 220 6019 6 4/22/2012 2.746 3.61 6.8 14 155 4363 220 6019 5 4/23/2012 2.493 3.57 6.9 14 155 4363 220 6019 6 4/24/2012 2.252 3.53 6.9 14 178 157 3345 4285 207 219 3888 5855 4 4/25/2012 2.389 3.51 6.4 14 208 160 4144 4274 268 222 5340 5819 5 4/26/2012 2.487 3.50 6.9 14 206 164 4264 4298 233 221 4833 5728 6 4/27/2012 2.278 3.47 6.9 14 163 4311 222 5764 6 4/28/2012 2.169 3.34 6.8 14 162 3917 221 5277 5 4/29/2012 2.172 3.20 6.8 14 162 3917 221 5277 4 4/30/2012 2.231 3.05 6.9 14 162 3917 221 5277 5 5/1/2012 2.143 2.92 7.0 14 184 164 3289 3868 240 222 4289 5201 5 5/2/2012 2.101 2.81 7.0 14 188 165 3287 3827 260 225 4555 5155 5 5/3/2012 2.904 2.74 7.0 14 186 171 4515 3855 234 233 5667 5197 6 5/4/2012 2.813 2.69 6.9 14 176 3822 238 5109 6 5/5/2012 2.679 2.64 6.9 14 179 3725 244 5046 5 5/6/2012 2.529 2.59 6.9 14 179 3725 244 5046 5 5/7/2012 2.318 2.55 7.1 14 179 3725 244 5046 3 5/8/2012 2.155 2.51 6.9 14 221 182 3973 3744 231 243 4151 4977 5 5/9/2012 2.002 2.48 6.9 14 212 184 3537 3729 231 242 3858 4897 5 5/10/2012 1.900 2.44 6.8 14 256 190 4051 3732 247 244 3913 4801 5 5/11/2012 1.821 2.41 7.1 15 192 3699 243 4690 5 5/12/2012 1.770 2.37 6.9 15 194 3675 245 4651 5 5/13/2012 1.707 2.34 6.9 16 194 3675 245 4651 4 5/14/2012 1.668 2.32 7.0 16 194 3675 245 4651 5 5/15/2012 1.606 2.29 7.0 16 242 197 3235 3641 242 244 3241 4542 5 5/16/2012 1.568 2.27 7.0 16 233 200 3046 3599 245 245 3203 4447 5 5/17/2012 1.538 2.25 7.0 16 249 213 3188 3733 235 245 3014 4361 4 5/18/2012 1.458 2.22 7.0 16 214 3753 241 4302 4 5/19/2012 1.440 2.18 6.9 16 213 3656 239 4163 4 5/20/2012 1.526 2.13 6.8 16 213 3656 239 4163 4 5/21/2012 1.645 2.08 6.9 16 213 3656 239 4163 4 5/22/2012 1.593 2.05 7.0 16 137 208 1827 3515 226 238 3003 4073 4 5/23/2012 1.618 2.02 7.1 16 229 209 3091 3485 217 237 2928 3992 5 5/24/2012 1.629 2.00 7.0 16 227 213 3084 3466 207 237 2812 3915 4 5/25/2012 1.547 1.97 7.0 16 213 3414 234 3805 4 5/26/2012 1.455 1.93 6.8 16 214 3343 235 3719 4 5/27/2012 1.387 1.90 6.9 16 214 3343 235 3719 4 5/28/2012 1.433 1.88 7.0 16 214 3343 235 3719 4 5/29/2012 1.388 1.85 7.0 16 264 218 3061 3322 247 236 2860 3653 4 5/30/2012 1.363 1.82 7.0 17 257 220 2925 3293 255 237 2899 3599 4 5/31/2012 1.404 1.80 7.0 17 251 225 2934 3268 257 238 3009 3508 4 6/1/2012 1.330 1.77 7.1 17 228 3267 236 3428 4 6/2/2012 1.314 1.72 6.8 17 231 3163 237 3241 4 6/3/2012 1.333 1.67 6.9 17 231 3163 237 3241 3 6/4/2012 1.300 1.62 7.0 16 231 3163 237 3241 4 6/5/2012 1.270 1.58 7.0 17 309 237 3269 3171 300 242 3177 3236 5 6/6/2012 1.282 1.55 6.9 17 295 241 3148 3169 307 246 3282 3239 4 6/7/2012 1.435 1.52 6.8 17 297 247 3548 3139 284 250 3398 3185 3 6/8/2012 1.457 1.51 7.1 17 250 3108 251 3134 4 6/9/2012 1.382 1.49 7.0 17 249 3030 252 3069 4 6/10/2012 1.367 1.47 7.0 17 249 3030 252 3069 4 6/11/2012 1.319 1.46 7.0 17 249 3030 252 3069 4 6/12/2012 1.286 1.44 7.1 17 264 250 2835 3015 259 252 2777 3046 4 6/13/2012 1.262 1.43 7.0 17 306 254 3223 3030 327 258 3443 3075 3 6/14/2012 1.258 1.42 7.1 17 255 3014 259 3062 3 6/15/2012 1.242 1.41 7.0 17 299 260 3100 3018 313 264 3241 3065 3 6/16/2012 1.216 1.40 7.1 18 261 3004 267 3069 5 6/17/2012 1.248 1.39 6.9 17 261 3004 267 3069 3 6/18/2012 1.240 1.38 7.0 17 261 3004 267 3069 4 6/19/2012 1.223 1.37 7.0 17 305 265 3105 3012 332 272 3385 3093 4 6/20/2012 1.325 1.36 7.0 18 293 267 3234 3027 324 275 3581 3128 4 6/21/2012 1.173 1.35 7.0 18 268 276 2621 3084 294 280 2877 3119 4 6/22/2012 1.182 1.33 6.9 18 280 3084 285 3134 3 6/23/2012 1.385 1.33 7.0 17 284 3084 292 3161 3 6/24/2012 1.267 1.32 7.1 18 284 3084 292 3161 4 6/25/2012 1.234 1.31 7.0 18 284 3084 292 3161 8 6/26/2012 1.213 1.30 7.0 18 296 285 2997 3077 280 291 2833 3136 4 6/27/2012 1.226 1.30 7.2 18 240 282 2450 3032 270 289 2761 3109 4 6/28/2012 1.193 1.29 7.2 18 272 282 2702 3007 307 294 3054 3123 4 6/29/2012 1.185 1.28 7.0 18 284 3013 296 3140 3 6/30/2012 1.179 1.28 7.0 18 287 3019 300 3151 3 7/1/2012 1.106 1.27 7.1 18 287 3019 300 3151 3 7/2/2012 1.200 1.27 6.9 18 287 3019 300 3151 3 7/3/2012 1.161 1.26 7.1 18 311 289 3011 3019 307 300 2971 3137 4 7/4/2012 1.072 1.25 6.9 19 261 287 2335 2970 282 299 2521 3093 3 7/5/2012 1.187 1.25 7.2 19 275 284 2721 2931 284 298 2811 3067 4 7/6/2012 1.179 1.25 7.0 19 284 2914 297 3050 3 10/12/2016 Page 7 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 7/7/2012 1.143 1.24 7.0 19 282 2861 298 3021 3 7/8/2012 1.128 1.23 7.1 20 282 2861 298 3021 3 7/9/2012 1.130 1.22 7.0 19 282 2861 298 3021 4 7/10/2012 1.118 1.21 7.0 20 289 283 2693 2848 295 298 2751 3000 4 7/11/2012 1.109 1.20 7.1 20 270 282 2500 2823 289 297 2674 2977 2 7/12/2012 1.089 1.20 7.0 19 315 286 2862 2825 319 302 2897 2986 3 7/13/2012 1.250 1.20 7.0 19 284 2795 300 2951 3 7/14/2012 1.136 1.19 7.1 20 284 2795 300 2951 3 7/15/2012 1.080 1.19 7.1 20 283 2769 299 2926 4 7/16/2012 1.048 1.18 6.8 21 283 2769 299 2926 3 7/17/2012 1.065 1.17 7.1 20 357 289 3171 2800 332 301 2950 2928 3 7/18/2012 1.056 1.17 7.1 20 326 291 2867 2805 314 302 2765 2917 3 7/19/2012 1.049 1.16 7.1 20 302 291 2646 2772 296 300 2590 2860 3 7/20/2012 1.055 1.15 7.1 20 291 2737 298 2804 4 7/21/2012 1.048 1.15 7.0 20 293 2746 298 2798 4 7/22/2012 1.071 1.15 7.0 20 293 2746 298 2798 4 7/23/2012 1.077 1.14 7.1 20 293 2746 298 2798 3 7/24/2012 1.050 1.13 7.0 20 328 296 2875 2756 308 299 2697 2790 4 7/25/2012 1.066 1.12 7.0 20 312 297 2773 2757 315 300 2801 2791 3 7/26/2012 1.046 1.12 7.0 20 300 297 2621 2731 300 301 2618 2776 3 7/27/2012 1.037 1.11 6.9 20 301 2752 304 2777 3 7/28/2012 1.043 1.11 6.8 20 304 2756 303 2754 3 7/29/2012 1.051 1.10 6.8 20 304 2756 303 2754 2 7/30/2012 1.030 1.10 6.9 20 304 2756 303 2754 3 7/31/2012 1.022 1.09 6.8 20 386 310 3287 2797 358 308 3052 2777 5 8/1/2012 1.013 1.09 6.8 20 331 312 2795 2797 322 309 2721 2773 4 8/2/2012 1.018 1.08 6.9 20 328 313 2785 2781 317 309 2692 2753 4 8/3/2012 1.015 1.08 6.9 21 317 2815 311 2771 3 8/4/2012 1.034 1.08 7.0 21 320 2823 314 2767 1 8/5/2012 1.025 1.07 7.0 21 320 2823 314 2767 3 8/6/2012 1.047 1.07 7.0 21 320 2823 314 2767 2 8/7/2012 1.008 1.06 6.8 21 341 322 2865 2826 326 315 2741 2765 3 8/8/2012 1.027 1.06 6.8 21 303 321 2594 2810 335 316 2870 2773 4 8/9/2012 1.048 1.06 7.1 21 324 323 2830 2819 333 319 2909 2784 3 8/10/2012 1.074 1.06 7.0 21 327 2844 321 2793 2 8/11/2012 1.044 1.05 6.9 21 328 2843 321 2784 2 8/12/2012 1.043 1.05 6.9 21 328 2843 321 2784 2 8/13/2012 1.032 1.04 7.0 21 328 2843 321 2784 2 8/14/2012 1.033 1.04 6.9 21 334 329 2878 2845 347 323 2991 2800 3 8/15/2012 1.046 1.04 7.1 21 299 326 2611 2829 326 324 2845 2803 2 8/16/2012 1.069 1.04 7.1 22 331 325 2951 2813 336 324 2997 2806 3 8/17/2012 1.070 1.04 7.0 22 325 2809 325 2810 2 8/18/2012 1.055 1.04 7.1 21 326 2822 327 2828 3 8/19/2012 1.051 1.04 7.1 21 326 2822 327 2828 2 8/20/2012 1.013 1.04 6.8 22 326 2822 327 2828 2 8/21/2012 1.009 1.04 6.9 21 333 327 2801 2821 347 328 2920 2835 3 8/22/2012 0.998 1.04 6.8 21 290 324 2411 2791 340 329 2831 2835 2 8/23/2012 0.998 1.04 7.0 21 309 323 2576 2770 356 333 2963 2854 3 8/24/2012 1.030 1.03 6.9 21 324 2770 334 2858 3 8/25/2012 1.017 1.03 7.1 22 326 2782 337 2878 2 8/26/2012 1.043 1.03 6.9 21 326 2782 337 2878 2 8/27/2012 1.034 1.03 7.0 21 326 2782 337 2878 2 8/28/2012 0.990 1.03 6.8 21 279 322 2304 2745 387 341 3195 2902 3 8/29/2012 1.008 1.03 7.0 21 226 315 1902 2685 431 347 3622 2954 3 8/30/2012 0.985 1.03 7.1 21 293 309 2406 2622 423 352 3475 2984 3 8/31/2012 0.971 1.03 7.0 21 307 2609 354 3004 3 9/1/2012 0.971 1.03 7.0 21 305 2594 357 3030 2 9/2/2012 0.940 1.02 7.0 21 305 2594 357 3030 2 9/3/2012 1.043 1.02 7.0 21 305 2594 357 3030 2 9/4/2012 0.986 1.02 6.9 21 305 2594 357 3030 2 9/5/2012 0.993 1.02 7.0 21 296 304 2454 2583 385 359 3188 3042 3 9/6/2012 0.961 1.02 7.0 21 272 299 2184 2531 356 362 2854 3051 2 9/7/2012 0.952 1.02 7.1 21 314 300 2489 2523 387 366 3071 3066 3 9/8/2012 0.973 1.01 6.9 21 298 2497 368 3079 4 9/9/2012 0.996 1.01 6.9 21 298 2497 368 3079 4 9/10/2012 0.938 1.01 6.9 21 298 2497 368 3079 2 9/11/2012 0.945 1.01 7.0 21 341 301 2689 2512 394 370 3107 3081 3 9/12/2012 0.979 1.00 6.9 21 332 304 2709 2526 358 370 2924 3070 3 9/13/2012 0.980 1.00 7.0 21 374 306 3059 2539 388 372 3171 3083 3 9/14/2012 1.005 1.00 6.9 21 307 2533 376 3101 2 9/15/2012 0.973 1.00 6.9 21 305 2499 379 3110 3 9/16/2012 1.008 0.99 7.0 21 305 2499 379 3110 3 9/17/2012 0.968 0.99 7.0 21 305 2499 379 3110 2 9/18/2012 0.973 0.99 6.9 21 344 308 2794 2521 369 379 2995 3101 3 9/19/2012 1.016 0.99 6.8 21 319 309 2699 2534 366 378 3101 3101 3 9/20/2012 0.971 0.99 7.1 21 386 313 3128 2557 390 381 3157 3118 3 9/21/2012 0.994 0.99 7.0 21 314 2569 384 3140 2 9/22/2012 0.991 0.99 6.8 21 315 2568 386 3155 3 9/23/2012 1.016 0.99 7.0 21 315 2568 386 3155 3 10/12/2016 Page 8 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 9/24/2012 0.996 0.99 6.9 21 315 2568 386 3155 2 9/25/2012 0.981 0.98 7.0 21 355 318 2906 2594 375 385 3068 3148 3 9/26/2012 0.991 0.98 7.0 21 303 317 2503 2587 332 382 2744 3119 2 9/27/2012 0.959 0.98 7.1 21 354 322 2832 2625 380 381 3041 3108 3 9/28/2012 0.967 0.98 7.0 21 329 2681 377 3069 2 9/29/2012 0.962 0.98 7.0 21 333 2704 373 3035 3 9/30/2012 1.008 0.98 7.1 21 333 2704 373 3035 4 10/1/2012 1.021 0.98 6.9 21 333 2704 373 3035 4 10/2/2012 0.982 0.98 6.9 21 335 333 2741 2707 363 373 2972 3030 3 10/3/2012 0.984 0.98 6.9 20 307 331 2520 2693 337 370 2765 3011 3 10/4/2012 0.986 0.98 6.9 20 333 331 2737 2696 338 368 2781 2996 3 10/5/2012 0.973 0.98 7.0 20 333 2714 367 2982 4 10/6/2012 0.978 0.98 6.8 20 338 2754 367 2992 3 10/7/2012 1.009 0.98 6.8 20 340 2776 366 2985 2 10/8/2012 0.956 0.98 6.9 20 340 2776 366 2985 3 10/9/2012 0.996 0.98 6.9 20 388 344 3219 2810 391 368 3247 3006 3 10/10/2012 0.948 0.98 6.9 20 385 347 3046 2827 406 371 3211 3020 4 10/11/2012 0.952 0.98 6.9 20 367 349 2915 2843 374 369 2970 3010 4 10/12/2012 0.973 0.98 6.8 20 350 2854 370 3017 4 10/13/2012 0.989 0.98 6.9 20 348 2837 368 3004 3 10/14/2012 1.177 0.99 6.9 20 348 2837 368 3004 2 10/15/2012 1.245 1.00 6.9 20 348 2837 368 3004 4 10/16/2012 1.061 1.00 7.1 20 344 348 3046 2853 362 368 3204 3020 4 10/17/2012 1.006 1.00 7.1 19 410 352 3437 2895 790 398 6629 3277 4 10/18/2012 1.016 1.00 6.7 20 358 353 3029 2911 421 402 3566 3318 3 10/19/2012 1.020 1.00 7.2 19 356 2928 405 3335 3 10/20/2012 1.148 1.01 7.0 19 353 2911 406 3350 3 10/21/2012 1.079 1.01 7.1 19 353 2911 406 3350 4 10/22/2012 1.212 1.02 7.1 19 353 2911 406 3350 4 10/23/2012 1.043 1.02 7.2 18 368 354 3200 2933 366 403 3183 3337 4 10/24/2012 1.062 1.02 7.1 19 292 350 2589 2909 344 398 3047 3316 4 10/25/2012 1.045 1.02 7.0 19 323 348 2817 2902 361 397 3147 3322 4 10/26/2012 1.054 1.03 7.1 18 351 2933 403 3366 4 10/27/2012 1.340 1.04 7.1 18 351 2941 404 3393 3 10/28/2012 1.377 1.05 6.9 18 351 2941 404 3393 3 10/29/2012 1.315 1.07 7.1 18 351 2941 404 3393 4 10/30/2012 1.937 1.10 7.2 18 237 342 3822 3009 274 394 4427 3473 4 10/31/2012 1.986 1.13 7.1 18 154 329 2542 2976 196 380 3246 3457 4 11/1/2012 1.781 1.15 7.0 18 180 317 2674 2971 217 370 3224 3475 4 11/2/2012 1.821 1.18 7.1 18 318 3006 372 3529 4 11/3/2012 1.545 1.20 6.9 18 317 3028 375 3592 4 11/4/2012 1.485 1.22 7.1 18 317 3028 375 3592 4 11/5/2012 1.452 1.23 7.1 18 317 3028 375 3592 3 11/6/2012 1.400 1.25 7.1 18 106 301 1239 2890 266 367 3106 3554 4 11/7/2012 1.346 1.26 7.0 18 212 294 2382 2854 257 359 2884 3507 4 11/8/2012 1.326 1.27 6.9 17 257 285 2837 2827 282 351 3118 3497 4 11/9/2012 1.265 1.28 7.0 17 277 2810 347 3519 4 11/10/2012 1.246 1.29 7.2 17 270 2801 345 3565 4 11/11/2012 1.434 1.31 7.2 17 270 2801 345 3565 4 11/12/2012 1.487 1.32 7.0 17 270 2801 345 3565 4 11/13/2012 1.388 1.33 7.1 17 214 266 2478 2776 271 339 3137 3532 4 11/14/2012 1.371 1.34 7.1 17 218 262 2496 2756 282 335 3225 3510 4 11/15/2012 1.344 1.34 7.2 17 247 255 2772 2737 299 330 3353 3521 4 11/16/2012 1.331 1.36 7.2 17 243 2683 295 3282 4 11/17/2012 1.634 1.38 6.8 17 234 2654 285 3258 4 11/18/2012 2.469 1.42 7.1 16 168 229 3455 2716 207 279 4263 3336 5 11/19/2012 5.566 1.57 7.0 16 126 222 5833 2938 192 272 8912 3734 6 11/20/2012 3.975 1.67 6.8 15 141 216 4682 3055 159 265 5271 3836 7 11/21/2012 3.499 1.74 6.9 15 216 3055 265 3836 7 11/22/2012 2.767 1.80 6.7 16 205 3044 258 3883 5 11/23/2012 2.776 1.86 6.8 15 199 3079 251 3947 5 11/24/2012 2.578 1.91 6.8 15 188 3101 242 4014 5 11/25/2012 2.348 1.95 6.9 15 188 3101 242 4014 5 11/26/2012 2.187 1.98 6.7 15 188 3101 242 4014 1 11/27/2012 1.974 2.00 6.9 15 185 188 3042 3097 250 242 4115 4022 5 11/28/2012 1.868 2.02 7.0 15 206 189 3205 3104 387 253 6030 4165 5 11/29/2012 1.741 2.01 7.1 15 221 188 3213 3061 307 255 4459 4167 5 11/30/2012 3.650 2.07 7.2 16 191 3101 260 4238 4 12/1/2012 5.063 2.18 6.6 14 192 3136 263 4323 8 12/2/2012 5.890 2.31 6.7 14 192 3136 263 4323 7 12/3/2012 6.225 2.47 6.7 14 192 3136 263 4323 6 12/4/2012 6.544 2.64 6.7 14 80 183 4359 3230 99 251 5403 4406 6 12/5/2012 5.993 2.79 6.6 14 64 175 3187 3227 94 239 4699 4427 7 12/6/2012 4.939 2.91 6.7 14 77 172 3151 3364 101 228 4160 4502 7 12/7/2012 4.346 3.01 6.7 14 169 3439 225 4627 6 12/8/2012 3.743 3.09 6.8 15 162 3489 221 4752 6 12/9/2012 3.378 3.16 6.8 15 162 3489 221 4752 6 12/10/2012 3.061 3.22 6.8 14 162 3489 221 4752 5 12/11/2012 2.999 3.27 6.9 15 167 163 4165 3541 206 220 5152 4783 5 10/12/2016 Page 9 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 12/12/2012 2.724 3.31 6.9 15 170 163 3865 3564 243 221 5520 4836 5 12/13/2012 2.635 3.35 6.9 15 134 157 2949 3598 176 214 3868 4888 5 12/14/2012 2.467 3.39 6.9 14 153 3683 209 5016 5 12/15/2012 2.567 3.43 6.9 14 145 3759 202 5154 5 12/16/2012 3.505 3.50 6.9 14 145 3759 202 5154 5 12/17/2012 4.317 3.59 6.8 14 145 3759 202 5154 6 12/18/2012 4.101 3.65 6.8 13 90 138 3088 3728 120 195 4104 5141 6 12/19/2012 5.546 3.65 6.8 13 96 136 4445 3613 148 191 6845 4969 5 12/20/2012 6.548 3.73 6.7 13 66 130 3591 3522 87 185 4751 4925 8 12/21/2012 6.103 3.82 6.7 13 130 3522 185 4925 7 12/22/2012 5.236 3.90 6.7 14 130 3522 185 4925 7 12/23/2012 4.924 3.97 6.6 14 130 3522 185 4925 7 12/24/2012 4.572 4.04 6.7 14 130 3522 185 4925 6 12/25/2012 3.736 4.09 6.7 13 148 131 4622 3606 215 187 6700 5062 6 12/26/2012 5.110 4.18 6.7 13 95 128 4042 3637 139 184 5923 5123 6 12/27/2012 4.275 4.26 6.8 13 80 121 2839 3623 121 175 4315 5138 6 12/28/2012 3.859 4.33 6.7 13 114 3655 158 5069 7 12/29/2012 3.498 4.39 6.7 14 105 3692 146 5120 6 12/30/2012 3.181 4.37 6.8 14 105 3692 146 5120 6 12/31/2012 2.981 4.30 6.8 14 105 3692 146 5120 5 1/1/2013 2.797 4.20 6.9 14 185 112 4306 3739 254 154 5926 5182 5 1/2/2013 2.696 4.08 6.9 14 132 113 2966 3684 147 154 3305 5048 6 1/3/2013 2.537 3.95 6.9 13 116 3632 158 5021 7 1/4/2013 2.383 3.83 7.0 14 171 124 3397 3648 174 164 3458 4925 6 1/5/2013 2.276 3.74 7.0 14 128 3690 169 4989 5 1/6/2013 2.267 3.67 7.0 14 128 3690 169 4989 5 1/7/2013 2.454 3.62 6.9 14 128 3690 169 4989 5 1/8/2013 2.894 3.61 6.9 13 142 129 3421 3669 171 169 4128 4923 5 1/9/2013 4.338 3.65 6.9 13 85 126 3069 3626 109 165 3944 4853 5 1/10/2013 3.799 3.68 6.8 13 103 121 3273 3562 111 158 3517 4736 6 1/11/2013 3.281 3.70 6.8 13 117 3539 152 4676 6 1/12/2013 2.967 3.71 6.8 13 116 3588 150 4743 6 1/13/2013 2.694 3.71 6.9 13 116 3588 150 4743 6 1/14/2013 2.480 3.71 7.0 13 116 3588 150 4743 5 1/15/2013 2.334 3.67 7.0 13 116 3588 150 4743 6 1/16/2013 2.202 3.60 7.0 13 204 123 3747 3601 213 155 3911 4679 6 1/17/2013 2.127 3.54 7.1 13 188 130 3339 3620 176 159 3123 4603 5 1/18/2013 2.034 3.42 7.1 13 195 138 3309 3532 199 163 3376 4337 5 1/19/2013 1.948 3.27 7.0 13 144 3527 169 4302 5 1/20/2013 1.860 3.12 7.1 13 144 3527 169 4302 5 1/21/2013 1.899 3.01 7.1 13 144 3527 169 4302 5 1/22/2013 1.774 2.91 7.1 13 244 152 3613 3534 299 179 4423 4311 5 1/23/2013 1.769 2.81 6.8 13 202 155 2987 3495 212 181 3128 4227 5 1/24/2013 1.765 2.75 7.1 13 211 160 3100 3386 217 182 3195 3976 5 1/25/2013 1.753 2.64 7.2 13 165 3336 185 3827 5 1/26/2013 1.739 2.55 6.9 13 172 3377 190 3786 4 1/27/2013 1.726 2.48 7.1 13 172 3377 190 3786 4 1/28/2013 1.859 2.43 7.1 13 172 3377 190 3786 5 1/29/2013 1.844 2.38 7.0 13 195 174 2999 3348 216 192 3321 3750 5 1/30/2013 1.963 2.35 7.0 13 204 176 3334 3347 216 194 3536 3735 5 1/31/2013 1.903 2.32 7.0 13 194 176 3071 3259 198 190 3142 3536 5 2/1/2013 1.860 2.29 6.9 13 180 3282 193 3554 5 2/2/2013 1.816 2.27 7.0 13 180 3282 193 3554 5 2/3/2013 1.744 2.25 7.0 14 181 3272 195 3562 4 2/4/2013 1.728 2.23 6.9 13 181 3272 195 3562 4 2/5/2013 1.789 2.21 7.0 14 210 183 3140 3262 243 198 3626 3567 4 2/6/2013 1.850 2.19 7.1 13 185 183 2846 3232 239 201 3687 3575 5 2/7/2013 1.853 2.16 7.1 13 200 187 3095 3209 214 204 3308 3517 6 2/8/2013 1.735 2.07 7.0 13 195 3220 212 3484 5 2/9/2013 1.685 2.00 7.1 14 203 3215 220 3481 5 2/10/2013 1.661 1.95 7.1 13 203 3215 220 3481 5 2/11/2013 1.583 1.90 7.1 13 203 3215 220 3481 5 2/12/2013 1.555 1.86 7.2 13 233 205 3025 3200 260 223 3372 3473 5 2/13/2013 1.497 1.83 7.0 13 243 208 3028 3188 284 228 3546 3478 5 2/14/2013 1.479 1.80 7.1 14 303 214 3739 3225 386 238 4760 3564 5 2/15/2013 1.459 1.78 6.7 14 215 3187 240 3539 5 2/16/2013 1.477 1.75 7.1 14 217 3176 245 3571 4 2/17/2013 1.424 1.73 9.1 14 219 3165 249 3587 4 2/18/2013 1.481 1.72 7.0 14 219 3165 249 3587 5 2/19/2013 1.431 1.70 7.2 14 290 224 3458 3187 315 254 3760 3600 5 2/20/2013 1.407 1.69 7.2 14 269 227 3159 3185 346 260 4060 3633 5 2/21/2013 1.422 1.68 7.0 13 321 233 3805 3199 406 268 4814 3661 5 2/22/2013 2.186 1.69 7.2 13 235 3215 272 3702 5 2/23/2013 2.049 1.70 7.1 13 237 3225 277 3744 5 2/24/2013 1.911 1.70 7.0 13 237 3225 277 3744 5 2/25/2013 2.037 1.71 7.1 13 237 3225 277 3744 5 2/26/2013 1.852 1.72 6.8 13 179 233 2759 3189 238 274 3676 3739 5 2/27/2013 1.794 1.72 7.1 13 217 232 3244 3193 282 275 4218 3773 5 2/28/2013 2.101 1.72 7.0 13 240 235 4203 3279 291 280 5099 3900 5 10/12/2016 Page 10 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 3/1/2013 2.064 1.73 7.0 13 237 3275 285 3928 6 3/2/2013 1.980 1.73 6.9 14 241 3292 292 3994 5 3/3/2013 1.883 1.73 7.0 14 241 3292 292 3994 4 3/4/2013 1.780 1.73 7.1 13 241 3292 292 3994 5 3/5/2013 1.754 1.73 6.9 14 251 242 3673 3321 320 294 4682 4047 5 3/6/2013 1.964 1.74 7.2 13 232 241 3801 3355 300 295 4914 4109 6 3/7/2013 1.898 1.74 7.2 13 237 243 3754 3399 301 299 4766 4190 5 3/8/2013 1.785 1.74 7.1 13 247 3442 303 4229 5 3/9/2013 1.697 1.73 7.2 13 251 3471 311 4306 5 3/10/2013 1.661 1.73 7.1 14 251 3471 311 4306 5 3/11/2013 1.616 1.73 7.0 13 251 3471 311 4306 5 3/12/2013 1.627 1.73 7.0 14 229 250 3111 3443 331 312 4492 4320 5 3/13/2013 1.686 1.73 7.2 14 217 247 3056 3415 280 310 3938 4293 5 3/14/2013 1.599 1.73 7.2 14 248 3445 314 4363 5 3/15/2013 1.575 1.74 7.0 14 299 253 3932 3515 330 317 4333 4424 4 3/16/2013 1.618 1.74 7.0 14 248 3496 312 4396 4 3/17/2013 1.592 1.75 7.0 14 248 3496 312 4396 4 3/18/2013 1.546 1.75 7.2 14 248 3496 312 4396 5 3/19/2013 1.729 1.76 7.1 14 276 251 3987 3534 325 313 4687 4418 5 3/20/2013 2.596 1.79 7.1 13 175 245 3798 3553 237 307 5131 4469 5 3/21/2013 2.552 1.83 7.0 13 179 237 3803 3578 207 300 4406 4515 7 3/22/2013 2.330 1.86 6.9 13 235 3610 296 4550 6 3/23/2013 2.152 1.89 7.0 13 228 3593 287 4528 5 3/24/2013 2.010 1.88 7.1 13 228 3593 287 4528 5 3/25/2013 1.884 1.88 7.0 14 228 3593 287 4528 5 3/26/2013 1.763 1.87 7.0 14 229 228 3362 3576 265 285 3897 4480 5 3/27/2013 1.726 1.86 7.1 14 243 229 3496 3570 327 288 4708 4496 5 3/28/2013 1.724 1.86 7.0 14 252 234 3623 3632 347 296 4989 4590 6 3/29/2013 1.624 1.85 7.1 14 235 3661 297 4619 4 3/30/2013 1.609 1.83 6.8 14 235 3616 298 4579 5 3/31/2013 1.503 1.82 8.0 15 235 3616 298 4579 6 4/1/2013 1.47 1.80 7.1 14.6 235 3616 298 4579 4/2/2013 1.42 1.78 6.9 14.4 286 239 3397 3600 340 301 4033 4537 4/3/2013 1.41 1.77 7.2 14.6 225 238 2655 3532 318 302 3750 4480 4/4/2013 1.65 1.77 7.2 14.6 259 239 3561 3524 340 303 4675 4480 4/5/2013 2.00 1.77 7.0 14.3 239 3503 304 4447 4/6/2013 2.87 1.80 6.9 13.9 239 3482 304 4420 4/7/2013 3.82 1.87 6.7 13.2 239 3482 304 4420 4/8/2013 3.05 1.91 6.8 13.4 239 3482 304 4420 4/9/2013 2.64 1.95 6.9 13.6 152 233 3357 3472 199 296 4382 4417 4/10/2013 2.57 1.98 6.9 13.9 126 225 2709 3418 182 288 3906 4381 4/11/2013 2.30 2.00 6.9 13.9 169 221 3229 3426 232 281 4445 4377 4/12/2013 2.20 2.02 6.9 14.2 221 3455 281 4411 4/13/2013 2.18 2.04 7.1 14.2 221 3455 281 4411 4/14/2013 2.29 2.06 7.1 14.2 214 3415 277 4417 4/15/2013 2.24 2.08 6.9 14.0 214 3415 277 4417 4/16/2013 2.12 2.10 7.0 13.8 172 211 3042 3386 199 271 3520 4348 4/17/2013 2.01 2.12 7.0 14.1 179 209 3002 3359 219 267 3663 4299 4/18/2013 1.97 2.12 7.0 14.0 216 205 3564 3328 256 262 4215 4266 4/19/2013 2.08 2.11 7.0 14.0 207 3292 264 4199 4/20/2013 1.94 2.09 7.0 14.5 209 3250 269 4182 4/21/2013 1.87 2.07 7.0 14.5 209 3250 269 4182 4/22/2013 1.78 2.06 7.1 14.5 209 3250 269 4182 4/23/2013 1.73 2.05 7.0 14.5 217 210 3127 3240 256 268 3693 4144 4/24/2013 1.69 2.04 7.2 14.7 224 211 3159 3235 293 270 4127 4143 4/25/2013 1.63 2.04 7.0 15.2 248 212 3376 3236 278 270 3780 4135 4/26/2013 1.56 2.03 6.9 15.3 210 3216 266 4091 4/27/2013 1.52 2.03 7.0 15.1 206 3182 259 4016 4/28/2013 1.52 2.02 7.2 15.5 206 3182 259 4016 4/29/2013 1.48 2.02 7.0 15.2 206 3182 259 4016 4/30/2013 1.45 2.02 7.1 15.1 259 210 3132 3178 290 262 3501 3976 5/1/2013 1.42 2.01 7.0 15.4 245 213 2887 3157 297 264 3507 3943 5/2/2013 1.55 2.02 7.0 15.6 281 212 3619 3173 330 264 4255 3958 5/3/2013 1.81 2.03 6.9 15.9 211 3213 259 3974 5/4/2013 1.38 2.02 7.1 16.3 207 3184 253 3916 5/5/2013 1.38 2.00 7.0 16.8 207 3184 253 3916 5/6/2013 1.33 1.95 7.1 18.7 207 3184 253 3916 5/7/2013 1.34 1.87 7.0 16.4 309 215 3447 3204 310 257 3458 3881 5/8/2013 1.27 1.81 7.2 16.5 233 217 2476 3152 289 259 3072 3823 5/9/2013 1.26 1.76 7.0 16.9 265 225 2798 3112 289 266 3047 3728 5/10/2013 1.40 1.72 6.7 17.2 232 3143 272 3714 5/11/2013 1.22 1.69 7.0 17.5 237 3136 276 3653 5/12/2013 1.22 1.65 6.4 17.6 237 3136 276 3653 5/13/2013 1.26 1.62 7.0 17.0 237 3136 276 3653 5/14/2013 1.18 1.59 7.2 17.3 302 242 2979 3124 332 280 3279 3624 5/15/2013 1.22 1.55 7.2 17.0 260 244 2640 3089 364 286 3699 3630 10/12/2016 Page 11 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 5/16/2013 1.22 1.52 6.8 17.4 306 253 3116 3094 367 298 3732 3645 5/17/2013 1.20 1.50 7.0 17.2 259 3102 304 3643 5/18/2013 1.20 1.47 7.2 17.3 262 3063 308 3596 5/19/2013 1.24 1.44 6.9 17.5 262 3063 308 3596 5/20/2013 1.26 1.42 7.4 17.4 262 3063 308 3596 5/21/2013 1.25 1.40 7.3 17.1 289 264 3005 3059 359 312 3737 3607 5/22/2013 1.31 1.38 7.2 16.8 242 263 2643 3029 294 311 3209 3578 5/23/2013 1.58 1.38 7.3 16.4 241 265 3189 3033 276 312 3646 3575 5/24/2013 1.41 1.37 7.0 16.7 268 3024 313 3533 5/25/2013 1.32 1.36 7.2 16.9 269 2994 316 3512 5/26/2013 1.37 1.35 7.2 17.1 269 2994 316 3512 5/27/2013 1.57 1.35 7.2 17.1 269 2994 316 3512 5/28/2013 1.44 1.35 6.9 17.0 250 268 3008 2995 284 314 3418 3505 5/29/2013 1.54 1.35 7.0 16.8 208 264 2665 2972 259 310 3324 3492 5/30/2013 1.40 1.35 7.0 16.8 274 265 3199 2976 343 314 4007 3528 5/31/2013 1.33 1.35 7.1 17.1 266 2983 315 3530 6/1/2013 1.34 1.34 7.2 17.4 265 2930 314 3469 6/2/2013 1.32 1.33 7.1 17.6 265 2930 314 3469 6/3/2013 1.28 1.32 7.0 17.6 265 2930 314 3469 6/4/2013 1.23 1.32 6.7 17.8 317 269 3252 2955 367 318 3768 3492 6/5/2013 1.23 1.31 7.0 18.2 242 267 2478 2921 353 320 3617 3501 6/6/2013 1.20 1.31 6.9 18.2 290 266 2914 2883 358 324 3597 3511 6/7/2013 1.17 1.31 7.0 18.0 268 2914 327 3545 6/8/2013 1.18 1.30 7.1 18.3 268 2924 330 3586 6/9/2013 1.19 1.30 6.9 18.3 268 2924 330 3586 6/10/2013 1.18 1.30 7.2 18.3 268 2924 330 3586 6/11/2013 1.13 1.29 7.1 18.1 318 272 2999 2930 392 334 3698 3595 6/12/2013 1.14 1.29 7.0 18.2 350 278 3338 2959 377 338 3594 3595 6/13/2013 1.16 1.29 7.0 18.5 363 282 3521 2998 387 341 3750 3629 6/14/2013 1.14 1.29 7.0 18.1 284 3025 340 3623 6/15/2013 1.10 1.28 7.0 18.7 282 3017 337 3614 6/16/2013 1.11 1.28 7.1 18.7 282 3017 337 3614 6/17/2013 1.09 1.27 7.2 18.8 282 3017 337 3614 6/18/2013 1.08 1.27 7.1 18.7 352 287 3184 3030 379 341 3425 3599 6/19/2013 1.09 1.26 7.1 18.8 346 292 3139 3038 485 351 4399 3657 6/20/2013 1.11 1.26 7.0 18.7 356 296 3291 3058 386 353 3565 3644 6/21/2013 1.10 1.25 7.2 18.7 301 3090 357 3678 6/22/2013 1.08 1.23 7.3 19.3 305 3082 364 3680 6/23/2013 1.23 1.23 6.9 19.0 305 3082 364 3680 6/24/2013 1.16 1.22 6.9 18.9 305 3082 364 3680 6/25/2013 1.18 1.22 7.0 18.9 284 304 2786 3059 341 362 3348 3655 6/26/2013 1.15 1.20 7.0 18.9 277 302 2656 3031 373 363 3583 3650 6/27/2013 1.20 1.20 7.1 19.0 289 305 2902 3023 355 368 3559 3660 6/28/2013 1.18 1.18 7.1 19.6 312 3051 377 3685 6/29/2013 1.11 1.17 7.1 19.7 315 3038 379 3659 6/30/2013 1.14 1.17 7.0 19.8 315 3038 379 3659 7/1/2013 1.11 1.16 7.0 19.8 315 3038 379 3659 7/2/2013 1.10 1.15 7.0 21.6 306 315 2810 3021 338 376 3105 3616 7/3/2013 1.10 1.15 6.9 20.0 269 311 2468 2981 371 376 3400 3601 7/4/2013 1.03 1.14 7.1 19.8 279 309 2399 2920 350 375 3011 3547 7/5/2013 1.07 1.13 7.1 19.7 314 2954 376 3541 7/6/2013 1.07 1.13 6.8 20.0 316 2958 378 3536 7/7/2013 1.08 1.13 7.1 19.9 316 2958 378 3536 7/8/2013 1.09 1.12 7.0 20.1 316 2958 378 3536 7/9/2013 1.11 1.12 7.2 20.3 319 316 2954 2957 349 376 3231 3513 7/10/2013 1.06 1.12 7.0 20.2 284 314 2516 2926 327 372 2899 3469 7/11/2013 1.09 1.12 7.2 20.2 306 313 2771 2910 376 371 3404 3448 7/12/2013 1.06 1.11 7.1 20.2 310 2877 371 3437 7/13/2013 1.12 1.11 7.2 20.4 306 2823 369 3411 7/14/2013 1.06 1.11 7.1 20.5 306 2823 369 3411 7/15/2013 1.06 1.11 7.1 20.5 306 2823 369 3411 7/16/2013 1.04 1.11 7.0 20.6 318 307 2760 2818 413 373 3579 3424 7/17/2013 1.02 1.10 7.2 20.6 275 304 2344 2784 364 372 3103 3401 7/18/2013 1.02 1.10 7.2 20.6 319 302 2722 2751 397 373 3391 3398 7/19/2013 1.01 1.10 7.1 20.8 299 2721 365 3321 7/20/2013 0.97 1.09 6.9 20.8 294 2674 363 3301 7/21/2013 1.02 1.09 6.9 20.8 294 2674 363 3301 7/22/2013 1.04 1.09 7.0 20.8 294 2674 363 3301 7/23/2013 1.00 1.08 7.0 21.1 294 2674 363 3301 7/24/2013 1.03 1.08 7.0 21.3 299 294 2578 2667 379 364 3263 3298 7/25/2013 1.00 1.07 7.1 21.2 316 297 2641 2655 399 369 3336 3297 7/26/2013 0.99 1.07 6.9 21.3 297 298 2456 2640 402 371 3321 3277 7/27/2013 1.00 1.06 6.9 21.3 299 2618 372 3254 7/28/2013 1.01 1.05 7.0 21.1 299 2618 372 3254 10/12/2016 Page 12 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 7/29/2013 1.01 1.05 6.9 21.3 299 2618 372 3254 7/30/2013 1.01 1.05 7.3 21.4 287 298 2417 2603 374 372 3150 3246 7/31/2013 1.05 1.04 7.2 21.5 310 299 2723 2611 381 373 3343 3253 8/1/2013 0.98 1.04 7.2 21.3 318 300 2609 2597 410 378 3361 3271 8/2/2013 0.99 1.04 6.9 21.4 302 2607 379 3261 8/3/2013 1.00 1.04 6.9 21.7 304 2624 381 3282 8/4/2013 1.00 1.03 7.0 22.3 304 2624 381 3282 8/5/2013 0.94 1.03 7.0 22.0 304 2624 381 3282 8/6/2013 0.95 1.02 6.8 21.9 319 305 2519 2616 391 382 3084 3267 8/7/2013 0.96 1.02 7.1 21.9 210 298 1672 2549 262 373 2089 3182 8/8/2013 0.96 1.01 7.2 21.9 253 294 2026 2482 298 370 2387 3122 8/9/2013 0.99 1.01 7.0 21.8 294 2480 373 3139 8/10/2013 0.99 1.01 7.2 21.7 294 2456 373 3117 8/11/2013 1.00 1.01 6.9 21.7 294 2456 373 3117 8/12/2013 0.99 1.00 7.0 21.8 294 2456 373 3117 8/13/2013 1.00 1.00 7.0 22.0 346 298 2892 2489 447 378 3734 3165 8/14/2013 1.00 1.00 7.2 21.8 280 296 2323 2477 347 376 2880 3144 8/15/2013 1.01 1.00 7.1 21.6 302 295 2538 2462 400 375 3359 3129 8/16/2013 0.98 1.00 7.1 22.0 297 2471 376 3131 8/17/2013 1.04 1.00 7.0 21.9 295 2450 374 3109 8/18/2013 0.99 1.00 7.1 22.0 295 2450 374 3109 8/19/2013 1.04 1.00 6.9 25.3 295 2450 374 3109 8/20/2013 0.97 1.00 7.1 22.1 306 296 2488 2453 428 378 3477 3137 8/21/2013 0.94 0.99 7.3 22.2 288 295 2262 2439 389 379 3059 3132 8/22/2013 0.98 0.99 7.1 22.1 320 297 2626 2451 416 382 3416 3150 8/23/2013 1.00 0.99 7.0 21.9 297 2442 382 3142 8/24/2013 1.03 0.99 6.9 22.0 295 2427 380 3128 8/25/2013 0.96 0.99 7.0 21.7 295 2425 379 3111 8/26/2013 0.99 0.99 7.0 21.9 295 2425 379 3111 8/27/2013 1.01 0.99 7.1 22.1 295 295 2484 2429 428 382 3601 3149 8/28/2013 1.01 0.99 7.1 22.1 309 296 2616 2443 446 387 3774 3194 8/29/2013 1.09 0.99 7.0 22.0 335 299 3055 2488 460 393 4200 3269 8/30/2013 1.01 0.99 7.0 22.1 299 2470 394 3263 8/31/2013 1.00 0.99 6.9 22.4 297 2459 393 3255 9/1/2013 0.99 0.99 6.9 22.3 297 2459 393 3255 9/2/2013 1.12 1.00 7.3 22.1 297 2459 393 3255 9/3/2013 1.08 1.00 7.0 21.8 324 299 2933 2495 385 392 3480 3272 9/4/2013 1.03 1.00 7.0 21.9 314 300 2689 2509 397 392 3400 3281 9/5/2013 2.18 1.04 7.1 21.8 471 311 8558 2940 530 402 9640 3750 9/6/2013 1.96 1.08 6.8 20.7 319 3038 413 3877 9/7/2013 1.43 1.09 7.1 21.4 324 3122 423 4002 9/8/2013 1.28 1.10 7.2 21.6 324 3122 423 4002 9/9/2013 1.23 1.11 7.1 21.7 324 3122 423 4002 9/10/2013 1.15 1.12 7.0 21.8 298 322 2854 3101 356 418 3413 3956 9/11/2013 1.12 1.12 7.2 22.1 262 318 2450 3055 327 411 3061 3892 9/12/2013 1.12 1.12 7.1 21.9 285 313 2654 3038 340 404 3164 3852 9/13/2013 1.05 1.13 7.1 21.6 316 3093 408 3926 9/14/2013 1.07 1.13 7.3 21.6 317 3139 409 3974 9/15/2013 1.12 1.13 7.3 21.5 317 3139 409 3974 9/16/2013 1.11 1.14 6.9 21.6 317 3139 409 3974 9/17/2013 1.08 1.14 6.9 21.5 308 316 2777 3111 393 407 3544 3941 9/18/2013 1.07 1.14 7.0 21.6 280 314 2505 3068 396 407 3545 3912 9/19/2013 1.04 1.14 7.2 21.7 325 315 2822 3092 452 408 3924 3944 9/20/2013 1.02 1.14 6.9 21.4 317 3156 410 4013 9/21/2013 1.05 1.15 6.9 21.3 317 3200 409 4062 9/22/2013 1.23 1.15 7.2 20.8 317 3200 409 4062 9/23/2013 1.14 1.16 6.8 20.8 317 3200 409 4062 9/24/2013 1.11 1.16 6.6 20.7 300 316 2771 3167 381 407 3524 4021 9/25/2013 1.09 1.17 6.7 20.7 283 313 2565 3124 367 404 3323 3971 9/26/2013 1.10 1.17 6.7 20.8 388 320 3560 3201 478 408 4391 4027 9/27/2013 1.23 1.18 6.8 20.3 321 3246 405 4047 9/28/2013 3.03 1.24 7.0 19.6 320 3262 400 4034 9/29/2013 3.82 1.33 6.4 19.8 320 3262 400 4034 9/30/2013 3.67 1.42 6.3 18.3 320 3262 400 4034 10/1/2013 2.99 1.49 6.4 18.1 129 305 3220 3258 186 384 4638 4081 10/2/2013 2.92 1.55 6.3 18.1 128 292 3107 3248 181 369 4409 4104 10/3/2013 2.43 1.60 6.8 18.1 131 279 2665 3229 171 354 3470 4103 10/4/2013 2.04 1.63 7.3 18.0 276 3270 351 4158 10/5/2013 1.81 1.62 6.9 18.7 260 2829 336 3701 10/6/2013 1.70 1.61 7.1 18.9 260 2829 336 3701 10/7/2013 1.64 1.62 6.9 18.1 260 2829 336 3701 10/8/2013 1.59 1.63 6.9 18.4 216 256 2856 2831 292 332 3868 3714 10/9/2013 1.52 1.64 7.3 18.3 237 255 3000 2843 294 330 3716 3714 10/10/2013 1.42 1.64 7.1 18.4 318 256 3760 2908 350 329 4142 3766 10/12/2016 Page 13 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 10/11/2013 1.40 1.65 6.9 18.7 256 2943 329 3820 10/12/2013 1.40 1.66 6.9 18.5 254 2968 328 3875 10/13/2013 1.37 1.67 6.9 17.9 254 2968 328 3875 10/14/2013 1.31 1.68 6.9 18.6 254 2968 328 3875 10/15/2013 1.27 1.69 7.2 18.4 278 255 2945 2966 385 333 4083 3891 10/16/2013 1.24 1.69 6.9 18.4 302 259 3133 2978 407 338 4224 3914 10/17/2013 1.24 1.70 7.2 18.5 326 260 3375 3020 405 339 4188 3960 10/18/2013 1.23 1.70 7.0 18.4 258 3060 335 3992 10/19/2013 1.20 1.71 7.2 18.2 253 3080 325 3998 10/20/2013 1.19 1.71 6.9 18.2 253 3080 325 3998 10/21/2013 1.20 1.72 6.9 18.2 253 3080 325 3998 10/22/2013 1.18 1.72 6.8 18.4 312 257 3067 3079 427 333 4199 4013 10/23/2013 1.17 1.72 7.0 18.2 317 262 3083 3079 439 340 4271 4032 10/24/2013 1.15 1.72 7.1 18.3 328 264 3148 3106 422 343 4054 4070 10/25/2013 1.14 1.72 6.8 18.4 262 3148 341 4127 10/26/2013 1.18 1.72 6.8 18.1 252 3113 330 4105 10/27/2013 1.18 1.72 6.8 18.0 252 3113 330 4105 10/28/2013 1.18 1.66 7.0 18.3 252 3113 330 4105 10/29/2013 1.16 1.57 7.0 18.1 335 258 3237 3123 432 338 4174 4110 10/30/2013 1.14 1.49 7.0 17.8 344 264 3264 3133 453 346 4294 4124 10/31/2013 1.08 1.42 6.9 18.0 367 281 3303 3139 446 365 4012 4079 11/1/2013 1.23 1.37 7.0 18.3 293 3141 379 4053 11/2/2013 1.26 1.33 7.0 17.6 307 3181 396 4102 11/3/2013 1.25 1.30 7.0 17.6 307 3181 396 4102 11/4/2013 1.25 1.28 7.0 17.3 307 3181 396 4102 11/5/2013 1.21 1.27 6.8 17.5 293 306 2966 3164 357 393 3617 4065 11/6/2013 1.33 1.26 7.0 17.5 284 304 3149 3163 367 391 4074 4065 11/7/2013 1.87 1.27 7.0 16.9 258 307 4037 3248 337 394 5266 4165 11/8/2013 1.68 1.27 6.9 16.9 312 3267 402 4200 11/9/2013 1.54 1.27 7.1 16.8 312 3226 406 4205 11/10/2013 1.44 1.28 6.9 17.1 312 3226 406 4205 11/11/2013 1.43 1.28 7.0 17.2 312 3226 406 4205 11/12/2013 1.35 1.28 7.0 17.1 269 309 3031 3211 377 404 4255 4208 11/13/2013 1.33 1.28 7.0 17.1 282 307 3137 3205 346 400 3844 4182 11/14/2013 1.29 1.28 7.1 17.1 300 308 3234 3226 366 399 3947 4173 11/15/2013 1.39 1.28 6.9 16.8 309 3233 398 4169 11/16/2013 1.37 1.29 7.1 16.8 307 3221 397 4167 11/17/2013 1.89 1.31 6.9 16.5 307 3221 397 4167 11/18/2013 2.30 1.35 6.8 16.3 307 3221 397 4167 11/19/2013 2.51 1.39 6.7 15.7 182 298 3826 3268 249 386 5222 4248 11/20/2013 2.05 1.42 6.9 15.8 177 289 3026 3251 225 375 3838 4219 11/21/2013 1.77 1.44 7.3 15.8 239 284 3520 3283 295 365 4344 4229 11/22/2013 1.65 1.45 7.1 15.7 281 3298 359 4226 11/23/2013 1.54 1.47 7.1 15.9 278 3311 354 4241 11/24/2013 1.51 1.48 7.2 16.1 278 3311 354 4241 11/25/2013 1.45 1.49 7.1 16.0 278 3311 354 4241 11/26/2013 1.41 1.50 7.1 15.6 278 3311 354 4241 11/27/2013 1.45 1.50 7.2 15.8 224 273 2713 3265 330 352 3993 4222 11/28/2013 1.29 1.51 7.0 16.0 315 272 3397 3277 381 348 4112 4217 11/29/2013 1.26 1.51 7.1 15.7 363 273 3818 3320 349 340 3667 4169 11/30/2013 1.40 1.52 7.1 15.7 266 3321 332 4182 12/1/2013 2.07 1.55 7.1 15.9 266 3321 332 4182 12/2/2013 2.02 1.58 7.0 14.9 266 3321 332 4182 12/3/2013 1.81 1.60 7.1 14.9 184 259 2782 3280 240 325 3622 4139 12/4/2013 1.67 1.61 7.2 14.8 209 256 2921 3254 276 321 3854 4118 12/5/2013 1.59 1.62 7.3 14.8 336 259 4450 3360 413 325 5470 4251 12/6/2013 1.55 1.63 7.4 14.6 257 3376 322 4264 12/7/2013 1.49 1.62 7.1 11.6 257 3321 321 4181 12/8/2013 1.46 1.61 6.9 9.1 257 3321 321 4181 12/9/2013 1.40 1.61 7.3 14.3 257 3321 321 4181 12/10/2013 1.40 1.60 7.1 14.5 394 267 4604 3420 404 327 4727 4223 12/11/2013 1.36 1.60 7.2 14.4 269 267 3067 3395 295 325 3358 4161 12/12/2013 1.37 1.60 7.1 14.3 287 269 3268 3412 260 316 2962 4069 12/13/2013 1.34 1.60 7.0 14.4 268 3433 314 4086 12/14/2013 1.33 1.60 7.3 14.4 265 3449 310 4097 12/15/2013 1.33 1.60 7.2 14.6 265 3449 310 4097 12/16/2013 1.28 1.60 7.3 14.3 265 3449 310 4097 12/17/2013 1.27 1.58 7.1 14.4 274 266 2896 3407 332 311 3512 4052 12/18/2013 1.24 1.54 7.2 14.6 273 266 2813 3364 291 310 3002 3977 12/19/2013 1.22 1.50 7.1 14.4 309 275 3155 3316 313 315 3195 3833 12/20/2013 1.28 1.47 7.2 14.0 283 3339 321 3832 12/21/2013 1.27 1.46 6.9 14.6 286 3324 324 3789 12/22/2013 1.25 1.44 7.0 14.5 286 3324 324 3789 12/23/2013 1.43 1.44 7.1 14.2 286 3324 324 3789 10/12/2016 Page 14 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 12/24/2013 1.35 1.43 7.0 14.7 274 285 3097 3306 300 322 3390 3759 12/25/2013 1.20 1.43 7.1 14.1 273 285 2726 3265 298 320 2978 3703 12/26/2013 1.32 1.42 7.1 14.2 438 295 4830 3369 317 320 3497 3689 12/27/2013 1.29 1.42 7.1 14.5 300 3416 319 3668 12/28/2013 1.24 1.42 7.0 14.4 299 3417 314 3633 12/29/2013 1.22 1.41 6.9 13.8 293 3384 312 3631 12/30/2013 1.24 1.41 7.0 14.2 293 3384 312 3631 12/31/2013 1.25 1.38 7.1 14.1 269 291 2802 3339 311 312 3235 3600 1/1/2014 1.18 1.35 7.2 14.0 269 290 2654 3290 385 317 3793 3614 1/2/2014 1.23 1.34 6.9 14.2 330 300 3376 3333 392 328 4010 3642 1/3/2014 1.18 1.32 7.0 14.4 307 3364 332 3625 1/4/2014 1.16 1.30 7.1 14.2 305 3274 325 3472 1/5/2014 1.18 1.29 7.1 14.3 305 3274 325 3472 1/6/2014 1.26 1.28 7.2 14.1 305 3274 325 3472 1/7/2014 1.44 1.28 7.2 13.8 285 303 3433 3286 321 325 3864 3502 1/8/2014 1.69 1.29 7.1 13.7 496 317 7002 3552 320 324 4519 3574 1/9/2014 1.74 1.31 7.2 13.4 387 317 5612 3624 229 312 3325 3474 1/10/2014 2.09 1.33 7.2 13.3 320 3666 313 3483 1/11/2014 3.26 1.39 8.5 12.6 323 3700 317 3527 1/12/2014 2.97 1.45 6.9 12.8 323 3700 317 3527 1/13/2014 2.51 1.49 7.0 13.2 323 3700 317 3527 1/14/2014 2.22 1.52 7.0 13.4 194 313 3595 3692 219 310 4052 3567 1/15/2014 2.00 1.54 7.0 13.4 158 302 2635 3616 167 300 2781 3511 1/16/2014 1.84 1.56 7.1 13.6 197 297 3021 3625 221 292 3389 3502 1/17/2014 1.73 1.58 7.0 13.5 298 3688 292 3541 1/18/2014 1.62 1.59 7.2 13.7 298 3732 290 3569 1/19/2014 1.53 1.60 7.1 13.9 298 3732 290 3569 1/20/2014 1.56 1.61 7.1 13.8 298 3732 290 3569 1/21/2014 1.45 1.61 7.1 13.6 243 293 2937 3671 276 289 3330 3551 1/22/2014 1.41 1.61 7.1 13.8 253 291 2979 3621 333 292 3916 3577 1/23/2014 1.35 1.61 7.2 13.8 366 297 4130 3695 342 295 3855 3610 1/24/2014 1.33 1.62 7.2 13.9 299 3770 295 3659 1/25/2014 1.33 1.62 7.1 13.9 287 3681 293 3672 1/26/2014 1.29 1.62 7.2 13.9 287 3681 293 3672 1/27/2014 1.31 1.62 7.0 13.8 287 3681 293 3672 1/28/2014 1.43 1.63 7.0 13.9 430 298 5134 3793 307 294 3668 3672 1/29/2014 1.43 1.63 7.3 13.6 218 293 2586 3707 283 293 3364 3650 1/30/2014 1.54 1.64 7.2 13.7 247 291 3177 3734 271 290 3486 3668 1/31/2014 1.52 1.65 7.1 13.5 293 3817 283 3658 2/1/2014 1.48 1.66 7.2 13.9 290 3853 274 3629 2/2/2014 1.46 1.67 7.1 13.9 290 3853 274 3629 2/3/2014 1.39 1.68 7.1 13.4 290 3853 274 3629 2/4/2014 1.37 1.69 7.3 13.4 268 288 3051 3792 332 279 3785 3641 2/5/2014 1.32 1.69 7.2 13.2 328 291 3620 3779 381 286 4208 3682 2/6/2014 1.35 1.68 7.2 13.0 262 289 2946 3745 306 285 3441 3651 2/7/2014 1.29 1.67 7.2 13.1 273 3494 282 3585 2/8/2014 1.24 1.65 7.1 13.2 264 3318 287 3606 2/9/2014 1.38 1.63 7.1 13.2 264 3318 287 3606 2/10/2014 1.50 1.57 7.2 13.4 264 3318 287 3606 2/11/2014 1.60 1.53 7.1 12.8 207 259 2758 3275 204 280 2722 3538 2/12/2014 1.61 1.50 7.2 13.0 147 251 1970 3181 227 276 3043 3503 2/13/2014 1.68 1.48 7.2 13.2 184 251 2566 3108 186 274 2600 3399 2/14/2014 1.83 1.47 7.2 12.9 258 3144 282 3447 2/15/2014 2.27 1.49 7.0 12.6 263 3154 287 3451 2/16/2014 3.63 1.55 7.0 12.9 263 3154 287 3451 2/17/2014 6.28 1.71 6.8 11.4 263 3154 287 3451 2/18/2014 5.67 1.84 6.8 11.5 76 248 3570 3186 80 271 3782 3477 2/19/2014 5.27 1.97 6.8 11.7 78 236 3413 3203 87 258 3821 3502 2/20/2014 4.90 2.08 6.7 11.7 74 224 3036 3210 190 252 7764 3818 2/21/2014 4.23 2.18 6.7 11.8 222 3227 246 3811 2/22/2014 3.66 2.25 6.7 12.1 210 3152 238 3807 2/23/2014 3.30 2.32 6.8 12.3 210 3152 238 3807 2/24/2014 3.26 2.38 6.9 11.8 210 3152 238 3807 2/25/2014 2.99 2.44 6.9 12.2 129 203 3201 3156 176 233 4383 3851 2/26/2014 2.77 2.49 6.8 12.8 150 200 3463 3178 159 228 3674 3839 2/27/2014 2.58 2.53 6.9 12.8 159 180 3413 3055 189 219 4068 3867 2/28/2014 2.42 2.56 6.9 13.1 177 3091 214 3906 3/1/2014 2.22 2.58 7.0 12.8 172 3084 210 3941 3/2/2014 2.29 2.61 7.0 12.6 172 3084 210 3941 3/3/2014 2.60 2.64 6.9 13.0 172 3084 210 3941 3/4/2014 2.56 2.68 6.9 12.9 172 3084 210 3941 3/5/2014 2.34 2.71 6.9 13.2 130 168 2537 3042 140 204 2730 3848 3/6/2014 5.54 2.85 6.8 12.3 53 152 2444 2995 56 183 2587 3756 3/7/2014 4.61 2.96 6.8 12.3 62 131 2396 2901 49 158 1885 3577 10/12/2016 Page 15 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 3/8/2014 5.12 3.09 6.8 12.3 121 2897 145 3588 3/9/2014 6.20 3.25 6.7 13.0 121 2897 145 3588 3/10/2014 5.94 3.41 6.7 12.3 121 2897 145 3588 3/11/2014 5.03 3.53 6.7 12.3 55 116 2300 2851 50 138 2097 3474 3/12/2014 4.37 3.62 6.6 12.8 57 111 2069 2795 54 132 1969 3366 3/13/2014 3.89 3.70 6.7 12.9 44 100 1428 2700 65 122 2110 3322 3/14/2014 3.81 3.77 6.8 13.1 96 2756 114 3344 3/15/2014 3.46 3.83 7.2 13.7 89 2772 108 3406 3/16/2014 4.40 3.92 7.1 12.8 89 2772 108 3406 3/17/2014 4.29 3.99 6.8 12.4 89 2772 108 3406 3/18/2014 3.79 3.99 6.7 12.8 89 2772 108 3406 3/19/2014 3.39 3.90 6.8 12.7 82 88 2334 2739 73 105 2066 3303 3/20/2014 3.08 3.81 6.8 13.0 104 90 2666 2669 98 107 2513 3205 3/21/2014 2.83 3.73 6.8 13.0 105 93 2491 2598 90 107 2126 3075 3/22/2014 2.65 3.65 6.8 13.7 94 2562 100 2684 3/23/2014 2.50 3.60 7.2 13.8 94 2562 100 2684 3/24/2014 2.35 3.55 6.9 14.3 94 2562 100 2684 3/25/2014 2.25 3.52 6.9 13.5 139 98 2601 2565 115 101 2159 2644 3/26/2014 2.29 3.49 7.0 13.3 135 100 2578 2566 116 102 2212 2613 3/27/2014 2.23 3.46 6.9 13.8 151 102 2816 2538 207 104 3854 2575 3/28/2014 2.46 3.45 6.7 13.7 98 2467 100 2490 3/29/2014 4.28 3.51 6.9 12.8 93 2388 93 2359 3/30/2014 3.96 3.56 6.7 13.0 93 2388 93 2359 3/31/2014 3.48 3.60 6.7 13.2 93 2388 93 2359 4/1/2014 3.05 3.63 6.7 13.6 81 92 2069 2364 53 90 1346 2281 4/2/2014 2.76 3.63 6.8 13.8 106 93 2441 2369 101 91 2328 2284 4/3/2014 2.54 3.63 6.9 13.2 116 95 2448 2375 103 91 2182 2278 4/4/2014 2.33 3.63 6.8 13.8 92 2363 88 2245 4/5/2014 2.28 3.52 6.9 13.7 95 2357 90 2219 4/6/2014 2.20 3.44 6.9 14.5 98 2353 94 2247 4/7/2014 2.09 3.34 6.8 15.1 98 2353 94 2247 4/8/2014 2.04 3.20 7.1 14.8 53 94 898 2241 88 93 1499 2189 4/9/2014 1.94 3.07 6.9 15.5 211 103 3399 2324 211 102 3405 2276 4/10/2014 1.86 2.96 6.9 14.4 200 113 3110 2382 215 114 3338 2365 4/11/2014 1.82 2.88 6.8 14.7 117 2406 118 2395 4/12/2014 1.75 2.81 7.0 14.8 124 2488 123 2419 4/13/2014 1.73 2.74 7.1 15.3 124 2488 123 2419 4/14/2014 1.66 2.68 7.0 15.4 124 2488 123 2419 4/15/2014 1.52 2.58 7.1 15.2 223 131 2831 2514 209 129 2658 2437 4/16/2014 1.63 2.49 7.1 14.7 239 139 3261 2567 281 140 3829 2537 4/17/2014 2.00 2.43 7.2 14.5 249 146 4152 2673 245 147 4090 2640 4/18/2014 1.79 2.38 7.0 15.0 151 2697 152 2681 4/19/2014 1.88 2.34 6.9 14.5 154 2700 156 2694 4/20/2014 1.73 2.30 6.9 15.4 159 2717 162 2742 4/21/2014 1.77 2.27 7.0 15.5 159 2717 162 2742 4/22/2014 2.00 2.26 7.0 14.7 226 164 3755 2797 243 168 4044 2842 4/23/2014 2.72 2.27 7.0 14.1 160 163 3642 2857 183 169 4159 2936 4/24/2014 3.35 2.31 6.8 14.2 119 162 3336 2910 147 172 4110 3075 4/25/2014 2.75 2.32 6.8 14.5 164 2935 176 3142 4/26/2014 2.52 2.33 6.9 14.5 165 2945 173 3082 4/27/2014 2.59 2.33 6.9 14.3 165 2945 173 3082 4/28/2014 2.27 2.27 6.9 14.9 165 2945 173 3082 4/29/2014 2.10 2.21 6.9 15.7 174 166 3055 2954 206 176 3612 3123 4/30/2014 2.00 2.16 6.9 16.2 177 167 2960 2954 210 178 3506 3150 5/1/2014 1.93 2.12 7.0 16.7 206 176 3317 3043 224 190 3608 3312 5/2/2014 1.82 2.09 6.9 16.2 181 3090 197 3388 5/3/2014 2.31 2.08 7.0 15.5 186 3143 205 3488 5/4/2014 2.79 2.10 6.8 15.1 186 3143 205 3488 5/5/2014 2.48 2.10 6.8 15.1 186 3143 205 3488 5/6/2014 2.21 2.10 6.9 15.2 142 183 2614 3102 179 203 3303 3474 5/7/2014 2.06 2.10 6.9 15.4 167 182 2861 3085 215 204 3686 3489 5/8/2014 2.12 2.10 6.9 14.9 180 191 3177 3248 224 214 3960 3665 5/9/2014 2.26 2.11 6.9 14.9 189 3236 214 3685 5/10/2014 2.17 2.13 7.0 16.8 188 3247 214 3714 5/11/2014 2.05 2.13 6.8 17.7 188 3247 214 3714 5/12/2014 1.92 2.14 6.8 16.5 188 3247 214 3714 5/13/2014 1.83 2.14 6.9 17.1 196 189 2987 3227 246 216 3758 3717 5/14/2014 1.77 2.15 6.9 17.8 197 190 2908 3204 256 219 3781 3722 5/15/2014 1.67 2.15 6.9 18.0 208 189 2893 3209 256 223 3560 3786 5/16/2014 1.62 2.15 6.9 16.8 185 3204 218 3783 5/17/2014 1.63 2.14 6.9 16.7 179 3125 216 3757 5/18/2014 1.72 2.13 7.0 16.6 179 3125 216 3757 5/19/2014 1.59 2.13 7.0 17.0 179 3125 216 3757 5/20/2014 1.48 2.12 7.0 17.4 215 182 2647 3089 254 219 3132 3709 10/12/2016 Page 16 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 5/21/2014 1.44 2.11 7.0 17.2 212 184 2551 3050 276 223 3315 3681 5/22/2014 1.43 2.09 7.0 17.9 245 186 2922 2991 306 227 3655 3653 5/23/2014 1.43 2.04 7.0 17.2 187 2941 231 3614 5/24/2014 1.38 1.98 7.0 17.5 193 2908 238 3573 5/25/2014 1.45 1.93 7.0 17.1 193 2908 238 3573 5/26/2014 1.50 1.90 7.0 17.3 193 2908 238 3573 5/27/2014 1.38 1.86 7.0 17.5 252 198 2893 2907 298 242 3421 3561 5/28/2014 1.35 1.83 6.9 17.3 277 203 3108 2921 312 247 3502 3557 5/29/2014 1.29 1.80 7.0 17.4 320 214 3429 2948 404 261 4333 3609 5/30/2014 1.28 1.78 7.1 17.8 217 2947 265 3616 5/31/2014 1.28 1.76 7.0 18.3 217 2916 269 3617 6/1/2014 1.28 1.74 6.9 18.4 217 2916 269 3617 6/2/2014 1.31 1.71 7.0 18.3 217 2916 269 3617 6/3/2014 1.22 1.65 7.0 18.3 330 226 3364 2950 415 280 4235 3665 6/4/2014 1.22 1.61 7.1 18.1 259 228 2629 2927 306 282 3104 3625 6/5/2014 1.13 1.58 7.0 18.8 203 233 1925 2878 209 284 1978 3530 6/6/2014 1.16 1.55 7.1 19.0 238 2880 289 3518 6/7/2014 1.16 1.51 7.0 19.3 243 2855 295 3481 6/8/2014 1.19 1.48 6.9 19.3 243 2855 295 3481 6/9/2014 1.15 1.44 6.9 19.3 243 2855 295 3481 6/10/2014 1.14 1.41 7.0 19.4 300 247 2845 2854 321 297 3045 3448 6/11/2014 1.14 1.39 7.0 20.3 314 252 2983 2863 356 301 3382 3443 6/12/2014 1.22 1.37 6.9 18.9 354 263 3608 2908 422 314 4300 3482 6/13/2014 1.16 1.35 6.9 18.7 268 2907 318 3459 6/14/2014 1.11 1.33 7.0 19.0 273 2909 323 3450 6/15/2014 1.13 1.31 7.0 19.0 273 2909 323 3450 6/16/2014 1.12 1.29 7.0 18.7 273 2909 323 3450 6/17/2014 1.06 1.27 7.2 18.5 471 289 4180 3006 560 341 4970 3567 6/18/2014 1.06 1.26 6.6 18.9 351 293 3106 3014 380 344 3362 3552 6/19/2014 1.07 1.24 7.6 20.7 256 296 2279 2987 208 341 1853 3461 6/20/2014 1.08 1.23 7.1 19.3 302 3021 346 3472 6/21/2014 1.09 1.22 7.1 19.6 307 3029 349 3457 6/22/2014 1.08 1.21 7.1 20.1 307 3029 349 3457 6/23/2014 1.24 1.20 7.1 19.4 307 3029 349 3457 6/24/2014 1.07 1.19 7.0 19.6 298 306 2644 2999 355 350 3154 3434 6/25/2014 1.25 1.18 7.1 20.3 262 303 2737 2981 340 349 3548 3442 6/26/2014 1.06 1.17 7.0 19.4 350 310 3104 2996 406 357 3598 3455 6/27/2014 1.06 1.16 7.1 19.4 313 2987 360 3451 6/28/2014 1.08 1.15 7.2 20.7 312 2950 357 3377 6/29/2014 1.06 1.15 6.9 20.9 312 2950 357 3377 6/30/2014 1.04 1.14 6.9 20.5 312 2950 357 3377 7/1/2014 1.02 1.13 7.0 21.8 330 314 2809 2939 438 363 3724 3404 7/2/2014 1.04 1.12 7.0 21.1 294 312 2563 2912 383 364 3336 3399 7/3/2014 1.03 1.11 7.1 21.3 331 312 2861 2877 372 361 3211 3326 7/4/2014 0.97 1.11 7.0 23.6 317 2896 365 3343 7/5/2014 1.04 1.10 7.1 20.1 326 2976 378 3457 7/6/2014 1.06 1.10 6.9 21.8 326 2976 378 3457 7/7/2014 1.03 1.09 6.9 21.6 326 2976 378 3457 7/8/2014 1.01 1.09 7.1 22.0 354 328 2995 2978 396 380 3347 3448 7/9/2014 1.04 1.09 7.0 21.1 300 326 2604 2951 388 380 3363 3442 7/10/2014 1.01 1.08 6.9 21.3 342 329 2870 2953 437 389 3671 3487 7/11/2014 1.00 1.08 7.0 21.8 330 2951 391 3495 7/12/2014 1.03 1.07 6.9 22.0 328 2896 389 3428 7/13/2014 1.03 1.07 7.0 21.7 328 2896 389 3428 7/14/2014 1.02 1.06 7.0 21.4 328 2896 389 3428 7/15/2014 1.03 1.06 7.0 22.1 327 328 2807 2889 381 388 3273 3416 7/16/2014 1.02 1.06 7.0 22.3 278 325 2361 2851 360 386 3057 3390 7/17/2014 1.00 1.05 7.0 21.3 335 315 2794 2752 406 375 3383 3277 7/18/2014 1.02 1.05 6.9 21.3 312 2725 375 3271 7/19/2014 1.01 1.05 6.8 21.7 317 2762 389 3389 7/20/2014 1.00 1.05 7.0 21.1 317 2762 389 3389 7/21/2014 1.00 1.04 7.1 21.2 317 2762 389 3389 7/22/2014 1.03 1.04 6.9 21.2 328 318 2819 2767 373 387 3203 3374 7/23/2014 1.11 1.04 6.9 20.4 301 317 2788 2768 352 385 3265 3367 7/24/2014 1.04 1.04 7.0 20.8 319 318 2773 2777 389 387 3377 3383 7/25/2014 1.03 1.03 7.0 21.3 322 2780 391 3370 7/26/2014 1.02 1.03 6.9 22.1 320 2754 390 3351 7/27/2014 1.03 1.03 7.1 22.4 320 2754 390 3351 7/28/2014 1.01 1.03 7.0 27.4 320 2754 390 3351 7/29/2014 1.01 1.02 7.0 24.9 398 326 3360 2800 258 379 2175 3260 7/30/2014 0.99 1.02 6.9 22.5 288 323 2372 2770 379 379 3127 3251 7/31/2014 0.99 1.02 7.0 22.9 332 323 2745 2765 399 377 3299 3221 8/1/2014 0.97 1.02 6.8 22.7 326 2781 376 3212 8/2/2014 0.99 1.02 7.0 23.0 325 2774 377 3212 10/12/2016 Page 17 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 8/3/2014 1.01 1.02 6.9 23.1 325 2774 377 3212 8/4/2014 0.99 1.02 7.0 23.3 325 2774 377 3212 8/5/2014 0.93 1.01 7.0 22.3 301 323 2326 2739 389 377 3009 3196 8/6/2014 0.99 1.01 7.0 23.3 271 320 2232 2703 369 377 3037 3185 8/7/2014 0.98 1.01 7.0 22.1 333 318 2724 2684 429 379 3511 3196 8/8/2014 1.00 1.01 7.0 22.1 319 2690 379 3184 8/9/2014 1.02 1.01 7.0 22.7 318 2675 374 3143 8/10/2014 0.72 1.00 6.9 23.8 318 2675 374 3143 8/11/2014 0.99 1.00 6.9 24.2 318 2675 374 3143 8/12/2014 1.08 1.00 6.8 22.0 350 320 3151 2711 416 377 3745 3189 8/13/2014 1.08 1.00 6.9 21.7 448 329 4031 2806 363 376 3267 3195 8/14/2014 1.06 1.00 7.1 22.1 329 329 2904 2813 404 378 3571 3216 8/15/2014 1.04 1.01 7.0 22.2 333 2847 379 3228 8/16/2014 1.04 1.01 7.0 24.4 333 2852 377 3216 8/17/2014 1.04 1.01 7.3 25.8 333 2852 377 3216 8/18/2014 1.02 1.01 7.0 22.9 333 2852 377 3216 8/19/2014 1.01 1.01 6.9 22.7 312 331 2616 2834 291 370 2443 3156 8/20/2014 0.97 1.01 6.9 21.9 310 330 2511 2811 351 369 2843 3134 8/21/2014 0.95 1.00 7.0 22.1 318 329 2523 2790 412 372 3268 3138 8/22/2014 0.98 1.00 7.0 22.2 331 2790 373 3129 8/23/2014 1.00 1.00 7.2 22.7 332 2791 372 3108 8/24/2014 1.03 1.00 7.1 22.1 332 2791 372 3108 8/25/2014 0.97 1.00 6.9 22.4 332 2791 372 3108 8/26/2014 0.97 1.00 7.0 23.3 306 330 2480 2767 384 373 3115 3108 8/27/2014 0.97 0.99 7.0 22.8 283 327 2286 2733 377 373 3048 3104 8/28/2014 0.97 0.99 6.9 22.3 359 324 2904 2700 408 384 3302 3185 8/29/2014 0.97 0.99 7.0 22.1 327 2725 384 3189 8/30/2014 0.97 0.99 7.0 21.6 327 2724 383 3180 8/31/2014 0.94 0.99 7.0 22.2 327 2724 383 3180 9/1/2014 1.00 0.99 7.0 22.3 327 2724 383 3180 9/2/2014 1.01 0.99 7.0 22.0 306 325 2587 2713 347 380 2931 3161 9/3/2014 0.97 0.99 7.1 21.5 390 330 3139 2744 356 378 2868 3140 9/4/2014 0.97 0.99 6.9 22.1 284 328 2293 2741 317 373 2564 3108 9/5/2014 0.94 0.99 7.0 22.9 333 2781 373 3114 9/6/2014 0.94 0.99 6.8 23.4 333 2785 369 3080 9/7/2014 1.00 0.99 7.1 23.1 333 2785 369 3080 9/8/2014 0.97 0.99 6.9 21.9 333 2785 369 3080 9/9/2014 0.98 0.99 7.1 22.1 331 333 2695 2778 374 369 3043 3077 9/10/2014 0.98 0.99 6.7 21.6 311 331 2536 2761 345 368 2814 3059 9/11/2014 0.95 0.99 7.0 22.0 307 328 2427 2709 358 363 2831 2993 9/12/2014 0.97 0.99 7.0 22.0 319 2608 363 2972 9/13/2014 0.97 0.98 7.0 22.9 318 2583 360 2922 9/14/2014 0.98 0.98 7.2 22.8 318 2583 360 2922 9/15/2014 0.97 0.98 6.9 23.0 318 2583 360 2922 9/16/2014 0.96 0.98 6.9 22.0 401 324 3201 2631 394 363 3145 2939 9/17/2014 0.96 0.97 7.1 22.0 301 323 2404 2614 383 364 3057 2948 9/18/2014 0.95 0.97 6.8 21.6 325 324 2588 2612 393 371 3130 2997 9/19/2014 0.95 0.97 7.1 23.3 325 2620 373 3009 9/20/2014 0.97 0.97 7.0 22.9 325 2628 370 2987 9/21/2014 0.99 0.97 7.1 22.7 325 2628 370 2987 9/22/2014 0.96 0.97 6.9 21.2 325 2628 370 2987 9/23/2014 1.12 0.97 6.9 21.2 299 323 2801 2642 378 370 3542 3030 9/24/2014 1.21 0.98 7.1 21.2 272 320 2753 2650 383 371 3879 3091 9/25/2014 1.07 0.99 7.1 21.2 325 321 2888 2679 410 373 3647 3129 9/26/2014 1.22 0.99 7.2 20.9 324 2709 373 3135 9/27/2014 1.05 1.00 7.0 21.1 321 2693 370 3121 9/28/2014 1.03 1.00 7.0 21.0 321 2693 370 3121 9/29/2014 1.02 1.00 6.9 20.7 321 2693 370 3121 9/30/2014 0.99 1.00 7.1 20.8 300 319 2481 2676 362 369 2991 3111 10/1/2014 0.98 1.00 7.1 20.7 298 318 2444 2660 413 372 3391 3131 10/2/2014 1.00 1.00 7.1 20.7 338 320 2820 2676 420 378 3504 3172 10/3/2014 0.95 1.00 7.0 20.9 315 2641 379 3195 10/4/2014 0.97 1.00 7.0 20.9 317 2670 384 3248 10/5/2014 1.00 1.00 6.9 20.9 317 2670 384 3248 10/6/2014 0.97 1.00 7.0 21.1 317 2670 384 3248 10/7/2014 0.98 1.00 6.8 20.9 289 315 2356 2646 367 383 2993 3228 10/8/2014 0.97 1.00 6.9 20.9 265 312 2147 2610 377 383 3058 3216 10/9/2014 0.97 1.00 6.9 20.6 372 314 3007 2632 413 385 3339 3237 10/10/2014 0.94 1.00 7.1 20.8 315 2640 389 3270 10/11/2014 0.99 1.00 7.2 20.8 315 2658 391 3306 10/12/2014 1.01 1.00 7.0 20.7 315 2658 391 3306 10/13/2014 1.11 1.01 6.9 20.6 315 2658 391 3306 10/14/2014 1.02 1.01 7.0 20.2 319 316 2719 2662 371 390 3159 3295 10/15/2014 1.02 1.01 7.0 20.1 350 318 2966 2684 463 395 3922 3340 10/12/2016 Page 18 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 10/16/2014 1.00 1.01 7.2 20.1 344 314 2865 2660 447 399 3729 3381 10/17/2014 0.98 1.01 6.9 20.0 315 2680 400 3406 10/18/2014 1.00 1.01 7.0 20.2 314 2687 400 3429 10/19/2014 1.01 1.02 6.9 20.3 314 2687 400 3429 10/20/2014 1.05 1.02 7.1 20.1 314 2687 400 3429 10/21/2014 1.01 1.02 7.2 20.2 300 313 2518 2674 363 397 3046 3400 10/22/2014 1.40 1.03 7.1 19.8 262 309 3064 2702 388 397 4545 3482 10/23/2014 1.49 1.05 7.1 19.3 236 305 2935 2712 261 388 3253 3461 10/24/2014 1.27 1.05 7.1 19.2 307 2709 389 3429 10/25/2014 1.38 1.06 7.2 19.2 306 2694 387 3411 10/26/2014 1.39 1.06 6.9 18.9 306 2694 387 3411 10/27/2014 1.23 1.07 7.0 18.9 306 2694 387 3411 10/28/2014 1.20 1.08 6.9 18.8 275 304 2752 2698 350 384 3498 3417 10/29/2014 1.15 1.08 7.0 18.8 276 302 2644 2694 340 381 3254 3406 10/30/2014 1.45 1.10 7.1 18.9 267 299 3224 2747 325 378 3928 3473 10/31/2014 1.63 1.12 7.1 18.6 299 2771 376 3479 11/1/2014 1.39 1.13 7.0 18.5 296 2767 372 3477 11/2/2014 1.36 1.14 7.0 18.6 296 2767 372 3477 11/3/2014 1.44 1.16 7.0 18.5 296 2767 372 3477 11/4/2014 1.42 1.17 7.1 18.4 296 2767 372 3477 11/5/2014 1.36 1.19 7.3 18.5 232 291 2631 2756 268 364 3046 3444 11/6/2014 1.61 1.21 7.0 18.3 200 284 2687 2782 239 354 3216 3461 11/7/2014 1.44 1.22 7.1 18.2 199 279 2393 2801 260 345 3129 3466 11/8/2014 1.33 1.24 7.1 18.2 272 2783 340 3477 11/9/2014 1.34 1.25 7.1 18.1 272 2783 340 3477 11/10/2014 1.25 1.26 7.2 18.1 272 2783 340 3477 11/11/2014 1.23 1.27 7.2 18.0 300 274 3072 2806 392 344 4021 3519 11/12/2014 1.17 1.27 7.1 17.8 290 275 2833 2808 373 346 3642 3528 11/13/2014 1.15 1.27 7.2 17.5 361 278 3458 2860 340 344 3262 3535 11/14/2014 1.12 1.28 7.0 17.4 272 2852 334 3505 11/15/2014 1.10 1.28 7.1 17.1 266 2851 325 3487 11/16/2014 1.15 1.28 7.0 16.8 266 2851 325 3487 11/17/2014 1.10 1.29 7.0 16.7 266 2851 325 3487 11/18/2014 1.09 1.29 7.2 17.1 364 274 3301 2886 419 332 3802 3511 11/19/2014 1.07 1.29 7.1 17.1 270 274 2411 2852 312 331 2786 3459 11/20/2014 1.06 1.29 7.1 17.1 264 271 2336 2839 282 325 2494 3420 11/21/2014 1.22 1.29 7.1 16.9 272 2821 320 3333 11/22/2014 1.31 1.28 6.9 16.7 275 2812 325 3340 11/23/2014 2.03 1.31 6.9 16.0 275 2812 325 3340 11/24/2014 1.86 1.32 6.9 16.2 204 269 3170 2840 250 319 3883 3382 11/25/2014 2.23 1.35 6.9 15.9 169 262 3149 2862 190 310 3536 3393 11/26/2014 1.93 1.37 6.9 16.3 216 259 3473 2902 212 303 3412 3394 11/27/2014 1.98 1.40 6.8 16.4 258 2913 300 3387 11/28/2014 2.27 1.44 7.1 15.9 256 2934 297 3397 11/29/2014 2.11 1.46 6.8 15.7 256 2910 295 3352 11/30/2014 1.83 1.46 7.2 15.6 256 2910 295 3352 12/1/2014 1.63 1.47 7.1 15.8 256 2910 295 3352 12/2/2014 1.51 1.48 7.2 15.5 230 254 2908 2910 209 288 2639 3298 12/3/2014 1.43 1.48 7.1 15.7 247 253 2944 2912 257 286 3068 3281 12/4/2014 1.37 1.48 7.1 15.7 243 253 2775 2903 214 281 2440 3225 12/5/2014 1.39 1.48 7.0 15.8 254 2922 282 3238 12/6/2014 1.40 1.47 7.4 15.8 258 2940 285 3240 12/7/2014 1.36 1.47 7.0 15.8 263 2986 288 3249 12/8/2014 1.31 1.47 7.1 15.8 263 2986 288 3249 12/9/2014 1.92 1.49 7.1 15.9 235 261 3756 3045 203 281 3249 3249 12/10/2014 2.20 1.52 6.8 15.2 157 254 2877 3033 149 272 2730 3212 12/11/2014 2.62 1.56 6.9 14.9 148 243 3226 3044 154 255 3368 3165 12/12/2014 2.20 1.60 6.9 15.1 239 3060 245 3128 12/13/2014 1.90 1.62 6.8 15.3 229 3027 238 3117 12/14/2014 1.75 1.64 6.9 15.3 229 3027 238 3117 12/15/2014 1.62 1.66 7.0 15.2 229 3027 238 3117 12/16/2014 1.50 1.67 7.0 15.3 210 227 2630 2997 209 235 2613 3078 12/17/2014 1.46 1.69 7.0 15.3 251 229 3053 3001 224 235 2726 3053 12/18/2014 1.55 1.70 7.1 15.4 203 218 2623 2952 205 219 2646 2971 12/19/2014 1.57 1.72 7.0 15.1 214 2994 212 2985 12/20/2014 2.89 1.78 7.3 14.7 209 3049 206 3026 12/21/2014 3.08 1.84 6.8 14.6 104 201 2672 3020 114 199 2932 3019 12/22/2014 2.52 1.88 6.8 14.8 127 196 2657 2994 122 194 2559 2986 12/23/2014 2.52 1.90 6.9 14.9 49 186 1027 2863 55 184 1157 2864 12/24/2014 2.74 1.93 6.8 14.8 185 2841 180 2791 12/25/2014 2.18 1.92 6.9 14.6 186 2817 179 2734 12/26/2014 2.05 1.93 6.8 14.9 184 2762 176 2677 12/27/2014 2.14 1.93 6.8 14.8 184 2762 176 2677 12/28/2014 2.03 1.93 6.9 14.8 159 182 2688 2757 165 175 2797 2686 10/12/2016 Page 19 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 12/29/2014 1.87 1.92 7.0 14.5 173 181 2696 2752 196 177 3064 2713 12/30/2014 1.76 1.92 7.0 14.4 197 182 2882 2761 216 179 3166 2744 12/31/2014 1.69 1.92 6.8 14.4 182 2761 179 2744 1/1/2015 1.56 1.92 6.9 14.3 179 2750 177 2751 1/2/2015 1.56 1.92 7.0 14.4 173 2735 171 2727 1/3/2015 1.53 1.93 7.0 14.3 168 2732 168 2751 1/4/2015 3.57 2.00 6.9 14.3 168 2732 168 2751 1/5/2015 6.48 2.17 6.5 11.2 168 2732 168 2751 1/6/2015 6.50 2.34 6.4 12.2 47 158 2571 2720 60 159 3254 2789 1/7/2015 6.40 2.51 6.4 12.6 55 151 2913 2734 61 152 3255 2823 1/8/2015 5.10 2.62 6.6 13.0 72 139 3046 2683 97 145 4129 2885 1/9/2015 3.92 2.68 6.6 13.3 138 2668 144 2897 1/10/2015 3.27 2.70 6.5 13.7 137 2621 144 2858 1/11/2015 2.86 2.72 6.7 13.8 137 2621 144 2858 1/12/2015 2.51 2.74 6.8 13.8 137 2621 144 2858 1/13/2015 2.30 2.76 6.8 13.9 155 138 2971 2648 165 145 3164 2882 1/14/2015 2.16 2.78 6.9 14.0 147 139 2643 2648 173 147 3114 2898 1/15/2015 2.10 2.80 6.9 13.9 151 135 2643 2649 173 145 3036 2929 1/16/2015 1.98 2.81 6.8 13.9 126 2618 139 2944 1/17/2015 3.10 2.87 6.9 13.7 119 2617 133 2969 1/18/2015 3.87 2.94 6.7 13.2 119 2617 133 2969 1/19/2015 3.75 2.97 6.6 13.3 119 2617 133 2969 1/20/2015 3.21 2.97 6.7 13.3 103 119 2761 2625 134 135 3592 3024 1/21/2015 2.86 2.99 6.8 13.7 103 117 2455 2608 135 136 3220 3079 1/22/2015 2.57 2.99 6.8 13.6 131 124 2817 2757 163 145 3498 3274 1/23/2015 2.60 2.98 6.8 13.5 124 2757 145 3274 1/24/2015 2.77 3.00 6.7 13.8 124 2757 145 3274 1/25/2015 2.53 3.02 6.8 13.9 124 2757 145 3274 1/26/2015 2.38 3.03 6.8 13.9 124 2757 145 3274 1/27/2015 2.14 3.03 6.8 13.8 159 124 2828 2769 181 146 3227 3310 1/28/2015 2.00 3.03 6.9 13.9 166 124 2779 2776 198 146 3309 3330 1/29/2015 1.94 3.04 6.9 13.8 180 122 2906 2778 208 146 3359 3346 1/30/2015 1.82 3.04 7.2 13.9 122 2778 146 3346 1/31/2015 1.82 3.05 6.9 14.1 122 2778 146 3346 2/1/2015 1.76 3.06 6.9 14.4 122 2778 146 3346 2/2/2015 1.73 3.07 6.9 14.0 122 2778 146 3346 2/3/2015 1.65 3.00 7.0 14.1 206 129 2840 2783 242 153 3335 3346 2/4/2015 1.79 2.85 7.1 14.1 214 135 3190 2812 285 163 4249 3410 2/5/2015 2.41 2.71 6.9 13.8 191 145 3836 2902 270 178 5417 3565 2/6/2015 3.55 2.61 6.7 13.4 152 2901 186 3588 2/7/2015 5.02 2.61 6.6 13.0 159 2889 194 3543 2/8/2015 4.96 2.65 6.5 13.1 159 2889 194 3543 2/9/2015 4.51 2.69 6.7 13.1 159 2889 194 3543 2/10/2015 3.90 2.72 6.5 13.2 85 153 2775 2880 114 188 3708 3556 2/11/2015 3.50 2.76 6.7 13.3 97 149 2826 2876 128 184 3735 3569 2/12/2015 3.11 2.78 6.8 13.6 125 147 3228 2895 167 184 4327 3652 2/13/2015 2.79 2.80 6.7 13.8 147 2914 184 3693 2/14/2015 2.55 2.82 6.8 14.0 147 2937 185 3748 2/15/2015 2.40 2.83 6.8 14.2 147 2937 185 3748 2/16/2015 2.28 2.80 6.9 14.1 147 2937 185 3748 2/17/2015 2.09 2.75 6.8 14.0 190 150 3317 2966 242 190 4223 3785 2/18/2015 1.97 2.69 6.9 14.1 206 154 3394 2997 258 195 4242 3817 2/19/2015 1.90 2.64 7.1 14.1 204 161 3227 3030 245 203 3882 3838 2/20/2015 1.83 2.61 6.8 14.1 166 3074 208 3885 2/21/2015 1.77 2.58 6.9 14.5 169 3095 212 3918 2/22/2015 1.75 2.55 6.8 14.5 169 3095 212 3918 2/23/2015 1.69 2.52 6.9 14.2 169 3095 212 3918 2/24/2015 1.62 2.49 6.9 14.3 186 170 2514 3051 216 212 2925 3841 2/25/2015 1.56 2.46 7.0 14.6 239 175 3117 3055 296 218 3854 3842 2/26/2015 1.80 2.45 7.0 14.3 208 178 3119 3076 252 223 3774 3881 2/27/2015 1.93 2.45 6.8 14.1 179 3099 225 3925 2/28/2015 1.81 2.44 6.8 14.5 179 3115 226 3973 3/1/2015 1.72 2.44 6.8 14.5 179 3115 226 3973 3/2/2015 1.66 2.43 6.7 14.4 179 3115 226 3973 3/3/2015 1.55 2.43 6.7 14.3 198 181 2562 3073 228 226 2957 3894 3/4/2015 1.53 2.42 6.9 14.7 206 182 2624 3041 248 228 3163 3842 3/5/2015 1.45 2.41 7.0 14.6 246 185 2990 3051 247 228 2997 3818 3/6/2015 1.41 2.40 6.9 14.6 183 3041 224 3785 3/7/2015 1.44 2.37 6.8 14.9 182 2974 220 3649 3/8/2015 1.44 2.30 6.8 14.9 182 2974 220 3649 3/9/2015 1.40 2.18 6.8 14.8 182 2974 220 3649 3/10/2015 1.35 2.06 6.8 14.8 219 185 2464 2935 302 226 3394 3629 3/11/2015 1.33 1.95 7.0 14.9 251 190 2773 2924 358 236 3961 3653 3/12/2015 1.29 1.86 7.0 15.1 254 202 2724 2920 298 249 3200 3617 10/12/2016 Page 20 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 3/13/2015 1.34 1.79 7.4 15.1 210 2927 258 3608 3/14/2015 2.12 1.76 6.8 14.8 217 2902 266 3548 3/15/2015 3.60 1.79 6.7 13.6 217 2902 266 3548 3/16/2015 2.74 1.79 6.6 13.7 217 2902 266 3548 3/17/2015 2.25 1.79 6.6 14.1 149 212 2788 2893 198 261 3717 3561 3/18/2015 1.99 1.78 6.8 14.2 165 209 2738 2882 214 257 3554 3560 3/19/2015 1.86 1.77 6.9 14.4 201 209 3119 2868 261 259 4049 3548 3/20/2015 1.78 1.76 6.8 14.6 210 2828 259 3494 3/21/2015 2.02 1.77 6.8 14.8 210 2794 260 3462 3/22/2015 1.87 1.77 7.0 14.8 210 2794 260 3462 3/23/2015 2.02 1.78 6.8 14.4 210 2794 260 3462 3/24/2015 2.08 1.79 6.9 14.4 166 207 2881 2801 197 255 3423 3459 3/25/2015 2.19 1.80 6.9 14.3 153 203 2797 2801 204 251 3721 3478 3/26/2015 2.02 1.82 6.9 14.5 160 201 2697 2814 211 251 3550 3522 3/27/2015 1.89 1.83 6.9 14.6 198 2791 248 3497 3/28/2015 1.80 1.83 7.0 14.9 197 2763 247 3474 3/29/2015 1.76 1.82 6.9 15.1 197 2763 247 3474 3/30/2015 1.66 1.82 7.0 15.0 197 2763 247 3474 3/31/2015 1.66 1.82 7.0 15.0 189 197 2613 2752 248 247 3424 3470 4/1/2015 1.67 1.82 7.0 15.0 189 196 2630 2743 247 247 3437 3468 4/2/2015 1.64 1.82 7.0 15.0 213 197 2903 2767 296 252 4041 3545 4/3/2015 1.69 1.82 6.8 15.0 197 2778 252 3574 4/4/2015 1.65 1.83 7.0 15.1 192 2761 253 3623 4/5/2015 1.55 1.84 6.9 15.2 192 2761 253 3623 4/6/2015 1.47 1.84 6.9 15.1 192 2761 253 3623 4/7/2015 1.52 1.84 7.1 15.2 217 194 2756 2760 307 257 3896 3644 4/8/2015 1.44 1.84 6.9 15.3 222 196 2659 2753 288 259 3452 3630 4/9/2015 1.39 1.84 7.0 15.3 249 198 2894 2784 310 260 3598 3644 4/10/2015 1.48 1.85 7.0 15.3 194 2785 252 3620 4/11/2015 1.56 1.86 7.0 15.2 189 2790 248 3655 4/12/2015 1.50 1.86 6.8 15.4 189 2790 248 3655 4/13/2015 1.51 1.84 6.9 15.0 189 2790 248 3655 4/14/2015 1.45 1.77 6.9 15.2 237 193 2875 2796 258 249 3129 3615 4/15/2015 1.40 1.73 6.9 15.3 216 195 2509 2776 280 251 3259 3589 4/16/2015 1.39 1.70 7.0 15.4 236 201 2730 2772 286 258 3315 3560 4/17/2015 1.34 1.68 6.9 15.6 204 2774 261 3561 4/18/2015 1.35 1.66 6.9 15.8 204 2745 261 3520 4/19/2015 1.36 1.64 6.8 16.0 204 2745 261 3520 4/20/2015 1.30 1.62 6.9 16.0 204 2745 261 3520 4/21/2015 1.26 1.60 6.9 15.8 244 207 2558 2731 291 263 3047 3484 4/22/2015 1.24 1.57 7.0 15.9 233 209 2418 2709 313 267 3246 3467 4/23/2015 1.26 1.55 6.9 15.9 263 216 2751 2699 298 274 3122 3445 4/24/2015 1.29 1.52 6.9 15.7 221 2692 279 3424 4/25/2015 1.25 1.49 6.8 16.1 226 2691 285 3414 4/26/2015 1.23 1.47 6.9 16.1 226 2691 285 3414 4/27/2015 1.21 1.45 6.9 16.3 226 2691 285 3414 4/28/2015 1.20 1.43 6.9 16.2 245 227 2457 2673 312 287 3130 3392 4/29/2015 1.18 1.41 7.0 16.4 253 229 2482 2660 318 289 3121 3373 4/30/2015 1.17 1.40 6.9 16.4 232 2663 325 295 3185 3355 5/1/2015 1.15 1.38 6.9 16.5 236 2666 299 3349 5/2/2015 1.21 1.37 6.9 16.9 238 2644 299 3292 5/3/2015 1.21 1.35 6.8 17.0 238 2644 299 3292 5/4/2015 1.17 1.33 6.8 16.9 332 245 3256 2695 299 3292 5/5/2015 1.18 1.32 7.0 16.8 299 250 2799 2703 357 303 3506 3308 5/6/2015 1.12 1.31 6.9 16.9 322 255 3048 2728 341 306 3190 3300 5/7/2015 1.14 1.30 7.0 17.1 258 2726 393 312 3726 3288 5/8/2015 1.09 1.29 6.9 17.1 261 2731 314 3275 5/9/2015 1.13 1.28 6.7 17.4 262 2717 314 3248 5/10/2015 1.13 1.27 7.0 17.5 262 2717 314 3248 5/11/2015 1.14 1.25 6.8 17.2 251 261 2566 2704 314 3248 5/12/2015 1.23 1.24 6.8 17.2 253 260 2452 2685 300 313 3069 3234 5/13/2015 1.16 1.23 6.9 17.2 257 260 2409 2665 301 312 2922 3212 5/14/2015 1.12 1.22 6.9 17.5 262 2649 301 315 2819 3190 5/15/2015 1.09 1.21 6.8 17.4 266 2660 318 3184 5/16/2015 1.10 1.20 6.7 17.5 268 2654 321 3173 5/17/2015 1.14 1.19 6.7 17.8 268 2654 321 3173 5/18/2015 1.13 1.19 6.8 17.9 288 270 2627 2652 321 3173 5/19/2015 1.09 1.18 6.9 18.0 293 272 2592 2647 340 322 3105 3168 5/20/2015 1.06 1.17 6.9 17.9 292 273 2517 2638 339 324 2998 3156 5/21/2015 1.03 1.16 6.9 17.8 275 2644 316 325 2723 3133 5/22/2015 1.01 1.15 6.8 17.9 279 2663 326 3124 5/23/2015 1.04 1.15 6.9 17.9 280 2655 329 3124 5/24/2015 1.02 1.14 6.8 18.1 280 2655 329 3124 5/25/2015 1.08 1.13 6.9 18.2 293 281 2519 2644 329 3124 10/12/2016 Page 21 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 5/26/2015 1.03 1.13 6.8 18.0 267 280 2299 2617 353 330 3038 3118 5/27/2015 1.03 1.12 6.9 18.3 315 283 2694 2623 324 330 2794 3095 5/28/2015 1.02 1.11 6.9 18.5 286 2635 362 334 3092 3092 5/29/2015 1.00 1.11 6.8 18.5 288 2648 335 3090 5/30/2015 0.97 1.10 6.8 18.5 288 2648 336 3082 5/31/2015 1.05 1.10 6.8 18.7 288 2648 336 3082 6/1/2015 1.04 1.09 6.8 18.4 288 2648 336 3082 6/2/2015 1.04 1.09 6.8 18.4 297 289 2576 2643 356 337 3088 3082 6/3/2015 1.13 1.09 6.9 19.5 263 284 2479 2583 341 337 3211 3091 6/4/2015 1.15 1.08 7.0 18.7 248 280 2391 2551 311 334 2994 3055 6/5/2015 1.26 1.09 7.0 19.0 276 2510 334 3044 6/6/2015 1.02 1.09 7.0 19.1 276 2510 329 2988 6/7/2015 1.07 1.08 6.9 19.4 276 2510 329 2988 6/8/2015 1.04 1.08 7.0 19.6 276 2510 329 2988 6/9/2015 1.01 1.08 6.9 19.6 290 277 2450 2505 363 331 3065 2993 6/10/2015 1.02 1.07 6.9 19.6 268 279 2275 2483 332 331 2815 2981 6/11/2015 1.01 1.07 7.0 19.5 283 281 2382 2478 348 335 2928 2971 6/12/2015 1.02 1.06 6.8 19.7 283 2483 337 2974 6/13/2015 1.01 1.06 6.8 19.7 283 2483 340 2987 6/14/2015 1.06 1.06 7.0 19.7 283 2483 340 2987 6/15/2015 1.03 1.05 7.0 19.8 283 2483 340 2987 6/16/2015 1.03 1.05 7.0 20.0 284 283 2440 2480 327 339 2807 2973 6/17/2015 1.03 1.05 6.9 20.1 282 283 2422 2464 355 341 3052 2979 6/18/2015 1.00 1.04 6.9 20.2 296 283 2478 2455 347 341 2908 2965 6/19/2015 1.00 1.04 6.9 20.3 282 2450 341 2963 6/20/2015 1.00 1.04 7.0 20.2 282 2450 343 2982 6/21/2015 0.98 1.04 6.9 20.5 282 2450 343 2982 6/22/2015 1.01 1.04 6.9 20.6 282 2450 343 2982 6/23/2015 1.00 1.04 6.9 20.6 294 283 2458 2451 342 343 2858 2973 6/24/2015 0.98 1.03 6.9 20.6 298 284 2440 2445 363 345 2971 2973 6/25/2015 1.00 1.03 6.9 20.6 349 290 2893 2491 365 345 3030 2972 6/26/2015 0.98 1.03 6.9 20.9 288 2474 347 2986 6/27/2015 0.99 1.03 6.9 20.9 288 2474 346 2977 6/28/2015 1.01 1.03 6.9 21.0 288 2474 346 2977 6/29/2015 1.02 1.03 6.9 21.1 288 2474 346 2977 6/30/2015 0.97 1.03 6.8 21.3 292 288 2374 2466 375 348 3046 2982 7/1/2015 0.98 1.03 6.9 21.2 261 286 2127 2442 335 347 2733 2965 7/2/2015 0.99 1.03 6.9 21.4 286 285 2355 2426 336 346 2767 2942 7/3/2015 1.00 1.02 6.9 21.4 287 2422 346 2921 7/4/2015 0.94 1.02 6.8 21.5 290 2425 349 2915 7/5/2015 1.00 1.01 6.8 21.4 290 2425 349 2915 7/6/2015 1.00 1.01 7.0 21.5 290 2425 349 2915 7/7/2015 0.99 1.00 6.8 21.6 275 289 2279 2413 328 347 2717 2900 7/8/2015 0.98 1.00 6.9 21.7 249 286 2041 2387 328 346 2694 2885 7/9/2015 0.99 1.00 6.8 21.8 298 287 2464 2388 354 345 2924 2875 7/10/2015 0.97 1.00 6.9 21.9 288 2396 346 2880 7/11/2015 1.03 1.00 6.9 21.8 289 2398 346 2876 7/12/2015 1.00 1.00 6.9 21.9 289 2398 346 2876 7/13/2015 1.00 1.00 6.8 21.9 289 2398 346 2876 7/14/2015 0.99 1.00 6.9 21.8 278 288 2307 2391 339 346 2813 2871 7/15/2015 0.99 1.00 6.9 21.9 280 287 2300 2384 350 346 2875 2871 7/16/2015 0.98 0.99 6.8 21.8 289 288 2371 2379 354 348 2901 2878 7/17/2015 0.97 0.99 6.8 21.8 288 2376 347 2864 7/18/2015 0.97 0.99 6.8 22.0 287 2367 347 2861 7/19/2015 0.98 0.99 6.8 22.1 287 2367 347 2861 7/20/2015 1.00 0.99 6.9 22.1 287 2367 347 2861 7/21/2015 1.00 0.99 6.9 22.0 307 289 2566 2383 388 351 3248 2891 7/22/2015 0.97 0.99 6.9 21.9 254 286 2061 2360 322 349 2618 2871 7/23/2015 0.97 0.99 7.0 22.1 292 286 2369 2353 362 350 2936 2877 7/24/2015 0.97 0.99 6.9 22.3 285 2347 349 2869 7/25/2015 0.97 0.99 6.8 22.1 280 2301 348 2856 7/26/2015 0.99 0.99 7.0 22.0 280 2301 348 2856 7/27/2015 0.97 0.99 6.6 22.0 280 2301 348 2856 7/28/2015 0.96 0.99 6.9 22.1 295 281 2362 2306 344 347 2759 2849 7/29/2015 0.95 0.98 6.9 22.2 286 281 2268 2303 359 348 2848 2849 7/30/2015 0.95 0.98 6.9 22.3 321 284 2546 2315 374 348 2966 2843 7/31/2015 0.95 0.98 6.9 22.3 285 2330 349 2851 8/1/2015 0.96 0.98 6.8 22.3 285 2328 350 2858 8/2/2015 0.99 0.98 6.9 22.2 285 2328 350 2858 8/3/2015 0.96 0.98 6.8 22.4 285 2328 350 2858 8/4/2015 0.98 0.98 6.8 22.5 295 286 2405 2334 376 352 3061 2874 8/5/2015 0.98 0.98 6.8 22.3 261 284 2127 2319 320 350 2613 2855 8/6/2015 0.98 0.98 6.8 22.3 309 287 2532 2337 372 353 3051 2879 8/7/2015 0.97 0.98 6.8 22.6 290 2360 355 2893 10/12/2016 Page 22 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 8/8/2015 0.97 0.98 6.9 22.5 289 2351 355 2891 8/9/2015 0.98 0.98 6.9 22.6 289 2351 355 2891 8/10/2015 0.97 0.98 6.8 22.5 289 2351 355 2891 8/11/2015 0.96 0.98 6.8 22.5 324 292 2597 2370 412 359 3300 2922 8/12/2015 0.99 0.97 6.9 22.6 291 291 2398 2372 355 359 2924 2922 8/13/2015 0.99 0.97 6.9 22.8 329 295 2705 2401 411 364 3377 2963 8/14/2015 1.00 0.97 6.8 22.5 296 2408 365 2969 8/15/2015 1.00 0.98 6.8 22.6 297 2411 366 2975 8/16/2015 1.00 0.98 6.9 22.5 297 2411 366 2975 8/17/2015 0.98 0.98 7.0 22.5 297 2411 366 2975 8/18/2015 0.99 0.98 6.9 22.5 331 300 2739 2437 356 365 2943 2973 8/19/2015 1.00 0.98 6.9 22.8 280 298 2328 2429 362 365 3012 2975 8/20/2015 1.00 0.98 6.8 23.5 313 299 2605 2432 347 362 2888 2950 8/21/2015 0.96 0.98 6.8 22.5 302 2460 365 2975 8/22/2015 0.97 0.98 6.8 22.5 303 2468 366 2979 8/23/2015 0.99 0.98 6.9 22.8 303 2468 366 2979 8/24/2015 0.97 0.98 6.8 22.6 303 2468 366 2979 8/25/2015 0.96 0.98 6.8 22.4 302 303 2410 2463 339 364 2703 2957 8/26/2015 0.94 0.97 6.9 22.5 310 303 2429 2461 353 363 2764 2944 8/27/2015 0.96 0.97 6.9 22.5 325 306 2602 2478 364 364 2916 2955 8/28/2015 0.97 0.98 6.8 22.5 307 2494 365 2963 8/29/2015 1.20 0.98 6.8 22.5 306 2490 364 2963 8/30/2015 1.09 0.99 6.7 22.4 306 2490 364 2963 8/31/2015 1.01 0.99 7.0 22.2 306 2490 364 2963 9/1/2015 0.99 0.99 6.8 22.1 292 305 2410 2484 346 363 2859 2955 9/2/2015 1.00 0.99 6.9 22.3 275 303 2293 2470 306 359 2550 2926 9/3/2015 0.96 0.99 6.9 22.0 307 304 2468 2475 340 356 2732 2902 9/4/2015 0.94 0.99 6.8 21.9 307 2501 359 2924 9/5/2015 0.97 0.99 6.9 22.0 307 2499 358 2914 9/6/2015 0.95 0.99 6.8 21.8 307 2499 358 2914 9/7/2015 1.05 0.99 6.8 21.9 307 2499 358 2914 9/8/2015 1.00 0.99 6.8 21.9 338 309 2810 2523 388 360 3230 2938 9/9/2015 0.96 0.99 6.8 21.9 285 307 2284 2506 345 359 2769 2926 9/10/2015 0.96 0.99 6.8 21.9 295 305 2361 2489 349 354 2797 2890 9/11/2015 0.95 0.99 6.7 22.0 306 2496 354 2888 9/12/2015 0.97 0.99 6.6 21.9 304 2478 350 2847 9/13/2015 1.02 0.99 6.7 21.9 304 2478 350 2847 9/14/2015 0.96 0.99 6.6 21.8 304 2478 350 2847 9/15/2015 0.95 0.99 6.6 21.7 335 307 2644 2491 333 348 2631 2830 9/16/2015 0.96 0.99 6.6 21.7 305 307 2435 2487 354 349 2831 2830 9/17/2015 0.97 0.99 6.6 21.7 342 307 2766 2489 387 351 3131 2844 9/18/2015 0.94 0.98 6.6 21.6 309 2501 350 2831 9/19/2015 0.97 0.98 6.6 21.7 309 2493 350 2826 9/20/2015 1.00 0.98 6.6 21.8 309 2493 350 2826 9/21/2015 0.95 0.98 6.6 21.6 309 2493 350 2826 9/22/2015 0.95 0.98 6.6 21.4 309 309 2457 2490 328 349 2604 2809 9/23/2015 0.92 0.98 6.6 21.5 301 309 2317 2478 338 348 2604 2794 9/24/2015 0.94 0.98 6.6 21.5 313 309 2458 2481 353 349 2772 2799 9/25/2015 0.93 0.98 6.8 21.4 309 2485 349 2802 9/26/2015 0.94 0.98 6.8 21.5 308 2475 347 2792 9/27/2015 0.96 0.98 6.9 21.3 308 2475 347 2792 9/28/2015 0.94 0.97 6.9 21.3 308 2475 347 2792 9/29/2015 0.93 0.96 6.8 21.3 291 307 2254 2458 319 345 2473 2768 9/30/2015 0.94 0.96 6.8 21.2 303 306 2388 2453 346 345 2724 2765 10/1/2015 0.93 0.96 6.8 21.1 322 309 2502 2460 336 344 2609 2747 10/2/2015 0.91 0.96 6.8 21.0 311 2473 347 2762 10/3/2015 0.96 0.96 6.8 21.1 311 2473 348 2765 10/4/2015 0.98 0.96 6.7 21.0 311 2473 348 2765 10/5/2015 0.94 0.96 7.0 21.0 311 2473 348 2765 10/6/2015 0.93 0.96 6.7 20.8 318 312 2478 2473 333 347 2594 2752 10/7/2015 1.01 0.96 6.8 20.7 304 311 2547 2479 353 347 2962 2767 10/8/2015 0.96 0.95 6.7 20.9 297 308 2367 2447 349 345 2785 2735 10/9/2015 0.94 0.95 6.7 20.8 310 2460 344 2732 10/10/2015 1.02 0.96 6.6 20.8 312 2468 344 2727 10/11/2015 0.99 0.96 6.6 20.7 312 2468 344 2727 10/12/2015 0.97 0.96 6.7 20.6 312 2468 344 2727 10/13/2015 0.95 0.95 6.8 20.6 321 312 2529 2472 338 344 2665 2722 10/14/2015 0.96 0.95 6.8 20.6 292 311 2348 2464 363 345 2921 2736 10/15/2015 0.94 0.95 6.7 20.5 303 309 2378 2445 312 344 2446 2723 10/16/2015 0.91 0.95 6.7 20.4 309 2445 343 2715 10/17/2015 0.95 0.95 6.7 20.5 306 2419 339 2680 10/18/2015 0.98 0.95 6.6 20.5 306 2419 339 2680 10/19/2015 0.94 0.95 6.7 20.5 306 2419 339 2680 10/20/2015 0.93 0.95 6.7 20.3 319 307 2488 2424 346 340 2697 2681 10/12/2016 Page 23 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 10/21/2015 0.93 0.95 6.7 20.3 331 309 2569 2434 363 341 2815 2691 10/22/2015 0.92 0.95 6.6 20.2 340 311 2618 2446 377 345 2903 2712 10/23/2015 0.93 0.95 6.7 20.2 312 2456 345 2721 10/24/2015 0.95 0.95 6.7 20.1 312 2456 345 2716 10/25/2015 1.12 0.96 6.7 19.9 312 2456 345 2716 10/26/2015 1.03 0.96 6.6 19.7 312 2456 345 2716 10/27/2015 0.98 0.96 6.7 19.8 311 312 2541 2462 377 347 3081 2744 10/28/2015 1.03 0.96 6.8 19.6 314 312 2686 2478 355 348 3035 2765 10/29/2015 1.11 0.97 6.6 19.7 348 316 3234 2548 405 354 3758 2857 10/30/2015 1.29 0.98 6.8 19.4 317 2560 354 2867 10/31/2015 2.81 1.04 6.7 18.6 317 2565 356 2889 11/1/2015 2.31 1.09 6.4 18.4 317 2565 356 2889 11/2/2015 1.77 1.12 6.4 18.5 317 2565 356 2889 11/3/2015 1.41 1.13 6.7 18.5 185 306 2177 2535 235 347 2767 2879 11/4/2015 1.26 1.14 6.9 18.7 202 299 2115 2505 246 339 2578 2858 11/5/2015 1.29 1.15 6.7 18.5 228 292 2448 2503 277 335 2976 2885 11/6/2015 1.18 1.16 6.7 18.8 292 2500 334 2879 11/7/2015 1.32 1.17 6.8 18.5 291 2511 333 2887 11/8/2015 1.38 1.18 6.5 18.6 291 2511 333 2887 11/9/2015 1.25 1.19 6.5 18.3 291 2511 333 2887 11/10/2015 1.22 1.20 6.7 18.2 282 290 2874 2539 335 333 3413 2927 11/11/2015 1.25 1.21 6.8 18.3 235 287 2440 2532 298 331 3100 2940 11/12/2015 1.35 1.22 6.7 18.0 255 282 2867 2556 323 329 3629 3009 11/13/2015 3.69 1.31 7.1 17.6 281 2572 327 3015 11/14/2015 5.20 1.46 6.7 15.5 279 2588 328 3063 11/15/2015 5.36 1.60 6.6 15.5 279 2588 328 3063 11/16/2015 4.73 1.73 6.9 15.9 279 2588 328 3063 11/17/2015 7.74 1.96 6.8 15.4 60 262 3881 2688 85 309 5486 3249 11/18/2015 7.13 2.16 6.7 15.2 54 247 3223 2726 64 292 3806 3289 11/19/2015 5.42 2.31 6.6 15.4 78 230 3537 2801 90 274 4067 3387 11/20/2015 4.07 2.42 6.7 15.5 223 2819 267 3431 11/21/2015 3.33 2.50 6.8 15.7 213 2835 258 3475 11/22/2015 2.84 2.56 6.9 15.8 140 207 3320 2873 163 250 3854 3504 11/23/2015 2.51 2.61 7.0 16.0 145 203 3045 2885 178 245 3729 3520 11/24/2015 2.31 2.65 7.0 15.9 163 200 3149 2902 172 240 3319 3507 11/25/2015 2.08 2.69 7.2 16.1 200 2902 240 3507 11/26/2015 1.85 2.72 7.2 16.3 192 2928 230 3537 11/27/2015 1.75 2.74 7.1 15.9 183 2947 221 3576 11/28/2015 1.69 2.76 7.2 15.8 169 2923 206 3560 11/29/2015 1.63 2.77 7.3 15.9 169 2923 206 3560 11/30/2015 1.52 2.73 7.2 15.6 169 2923 206 3560 12/1/2015 1.75 2.71 7.0 15.6 242 175 3526 2969 222 207 3238 3536 12/2/2015 1.95 2.72 7.1 15.4 306 184 4985 3113 144 202 2343 3450 12/3/2015 2.25 2.74 7.2 15.1 274 190 5139 3325 77 191 1444 3356 12/4/2015 2.35 2.78 6.9 15.0 189 3418 187 3416 12/5/2015 2.29 2.81 7.0 15.1 186 3499 179 3452 12/6/2015 2.30 2.85 6.9 15.4 186 3499 179 3452 12/7/2015 3.78 2.93 7.1 14.8 186 3499 179 3452 12/8/2015 7.73 3.14 6.8 13.9 66 177 4227 3555 80 172 5158 3584 12/9/2015 8.66 3.39 6.5 13.2 35 167 2498 3479 41 162 2960 3539 12/10/2015 8.67 3.64 6.6 13.1 40 150 2880 3480 43 141 3108 3517 12/11/2015 8.18 3.87 6.6 13.4 41 136 2808 3506 43 123 2934 3505 12/12/2015 7.89 4.09 6.4 13.5 59 122 3891 3579 46 103 3026 3462 12/13/2015 7.41 4.21 6.5 13.7 63 118 3876 3599 49 100 3030 3434 12/14/2015 6.43 4.25 6.5 13.8 63 114 3364 3584 76 98 4073 3474 12/15/2015 5.47 4.26 6.7 14.1 79 112 3617 3586 88 98 4012 3505 12/16/2015 4.81 4.26 6.7 14.2 109 112 4369 3630 136 100 5461 3614 12/17/2015 6.20 4.21 6.8 13.8 115 3615 101 3504 12/18/2015 7.74 4.23 6.7 13.3 119 3639 103 3485 12/19/2015 7.22 4.29 6.6 13.5 122 3646 104 3446 12/20/2015 6.85 4.38 6.7 13.5 122 3646 104 3446 12/21/2015 7.65 4.53 6.6 13.0 47 117 2991 3605 56 101 3573 3454 12/22/2015 7.39 4.68 6.5 13.3 48 111 2960 3583 49 94 3022 3402 12/23/2015 7.94 4.86 6.6 12.9 83 107 5508 3737 70 87 4636 3459 12/24/2015 8.03 5.05 6.5 13.0 104 3776 81 3468 12/25/2015 7.07 5.22 6.6 13.2 104 3776 81 3468 12/26/2015 6.21 5.36 6.5 13.3 104 3776 81 3468 12/27/2015 5.60 5.49 6.6 13.3 104 3776 81 3468 12/28/2015 4.88 5.60 6.7 13.6 90 103 3661 3769 118 84 4799 3551 12/29/2015 4.38 5.69 6.7 13.6 80 101 2919 3719 90 84 3290 3536 12/30/2015 3.86 5.76 6.8 13.6 108 102 3475 3705 115 86 3705 3545 12/31/2015 3.49 5.82 6.7 13.6 94 3716 78 3563 10/12/2016 Page 24 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 2011 Average 1.86 226.95 2699.40 200.05 2407.85 Max 6.40 3.82 637.50 442.43 5513.20 3519.46 556.00 433.00 5623.04 3860.09 Min 0.80 52.75 1666.45 41.00 1711.06 2012 Average 2.15 229.83 3271.60 265.72 3953.76 Max 6.69 4.47 409.50 355.70 9043.92 4940.69 789.84 405.74 11605.67 6771.54 Min 0.94 63.64 1239.30 87.00 2460.05 2013 Average 1.96 214.45 3405.86 256.05 4058.96 Max 4.34 4.20 320.90 252.66 4305.63 3739.11 406.00 317.38 5925.60 5181.90 Min 1.41 84.83 2759.27 109.00 3122.82 2014 Average 1.69 247.24 2891.12 281.96 3265.88 Max 6.28 3.99 495.90 333.27 7002.30 3853.49 560.00 400.33 7763.86 3940.90 Min 0.72 43.99 898.26 49.00 1156.72 2015 Average 1.94 229.79 2763.53 270.73 3229.79 Max 8.67 5.82 348.50 316.95 5508.06 3775.95 412.00 366.25 5486.49 3972.60 Min 0.91 43.99 898.26 49.00 1156.72 Monthly Data 1/31/2011 2.29898 3.53 97.92 2536.53 86.25 2248.27 2/28/2011 3.7755 2.15 156.16 2711.90 122.58 2132.16 3/31/2011 3.65229 3.71 92.72 2722.37 83.21 2467.13 4/30/2011 2.05888 2.73 121.93 2607.39 103.67 2227.81 5/31/2011 1.49341 1.86 174.17 2656.76 149.77 2288.03 6/30/2011 1.11995 1.24 262.67 2689.38 194.36 1992.24 7/31/2011 1.00432 1.07 305.79 2718.39 243.58 2165.30 8/31/2011 0.99304 1.01 312.74 2629.41 253.50 2129.88 9/30/2011 0.97059 0.97 296.20 2370.54 252.00 2016.01 10/31/2011 0.9328 1.00 378.41 2939.52 342.42 2762.68 11/30/2011 1.646 1.61 307.90 3315.68 329.82 3685.02 12/31/2011 2.12064 1.41 219.08 2472.51 241.08 2770.34 1/31/2012 3.14745 2.52 161.00 2745.68 189.23 3299.43 2/29/2012 3.76331 2.56 182.81 3749.23 204.93 4307.33 3/31/2012 6.69242 4.01 150.48 4826.25 205.25 6620.16 4/30/2012 2.23128 3.05 162.02 3916.62 220.83 5277.31 5/31/2012 1.40396 1.80 225.11 3268.05 238.14 3508.06 6/30/2012 1.17936 1.28 286.85 3019.47 299.75 3150.69 7/31/2012 1.0223 1.09 310.17 2797.13 307.62 2776.85 8/31/2012 0.97147 1.03 306.88 2608.80 354.15 3003.97 9/30/2012 1.00814 0.98 332.54 2703.82 373.33 3035.13 10/31/2012 1.98563 1.13 328.51 2975.71 380.20 3456.76 11/30/2012 3.65016 2.07 190.83 3100.66 259.69 4238.34 12/31/2012 2.98059 4.30 105.50 3691.91 145.75 5119.92 1/31/2013 1.90281 2.32 176.40 3259.03 189.86 3536.13 2/28/2013 2.10091 1.72 234.75 3279.01 279.86 3900.23 3/31/2013 1.50323 1.82 235.02 3616.37 297.50 4578.55 4/30/2013 1.44762 2.02 5/31/2013 1.328 1.35 6/30/2013 1.13955 1.17 7/31/2013 1.05219 1.04 8/31/2013 0.99684 0.99 9/30/2013 3.67044 1.42 10/31/2013 1.0785 1.42 11/30/2013 1.39637 1.52 12/31/2013 1.24717 1.38 1/31/2014 1.5184 1.65 2/28/2014 2.41807 2.56 3/31/2014 3.47683 3.60 4/30/2014 2.00182 2.16 5/31/2014 1.28322 1.76 6/30/2014 1.03513 1.14 7/31/2014 0.9915 1.02 8/31/2014 0.94006 0.99 9/30/2014 0.99056 1.00 10/31/2014 1.62527 1.12 11/30/2014 1.82794 1.46 12/31/2014 1.69387 1.92 10/12/2016 Page 25 OF 26 WASTEWATER TREATMENT OPERATIONS REPORT 2011 - Present CH2M HILL Calculation Permit No: WA0020982 Facility Name: City of Centralia Receiving Water: Chehalis Plant Type: Activated Sludge INFLUENT Date Influent Flow Total Influent Flow 30- day avg Influent pH Influent Temperature Influent BOD Concentration Influent BOD Concentration 30-day avg Influent BOD Influent BOD 30- day avg Influent TSS Concentration Influent TSS Concentration 30-day avg Influent TSS Influent TSS 30- day avg Influent Dissolved Oxygen MGD MGD oC mg/L mg/L lbs./day lbs./day mg/L mg/L lbs./day lbs./day mg/L 1/31/2015 1.82084 3.05 2/28/2015 1.80909 2.44 3/31/2015 1.65524 1.82 4/30/2015 1.17495 1.40 5/31/2015 1.04619 1.10 6/30/2015 0.97406 1.03 7/31/2015 0.95212 0.98 8/31/2015 1.00649 0.99 9/30/2015 0.94382 0.96 10/31/2015 2.80821 1.04 11/30/2015 1.52453 2.73 12/31/2015 3.49291 5.82 10/12/2016 Page 26 OF 26 Appendix F City of Centralia Sewer Collection System Mapping and Data (on CD) Appendix G Plant Design Data APPENDIX B Composting Facility Design Criteria Description Value Amendment Storage Volume, Phase 1/Phase 2 35 CY/2,700 CY Storage Time, Phase 1/Phase 2 1 week/6 months Pile Depth, Phase 1/Phase 2 6 feet/10 feet Compost Curing Volume, Phase 1/Phase 2 304 CY/1,600 CY Curing Time, Phase 1/Phase 2 3 months/6 months Pile Depth, Phase 1/Phase 2 10 feet/10 feet Compost Aeration Pile Volume, Phase 1/Phase 2 207 CY/207 CY Composting Time 28 days Pile Depth 8 feet Aeration Fans Number, Phase 1/Phase 2 3/10 Type Centrifugal Capacity 450 cfm, 7.5 in w.c. Power 3 hp Biofilter Fan Number 1 Type Centrifugal Capacity 2700 cfm, 10 in w.c. Power 10 HP Biofilter Design airflow 2 CFM/SF Expected removal efficiency 98% for hydrogen sulfide; 80% for odor Volume 203 CY Media Wood and /or bark Filter Depth 4 feet Stormwater Retention Pond Pond Bottom Dimensions 50 feet long, 26 feet wide Side slope 2 horizontal:1 vertical Depth 7 feet, including 2 feet of freeboard Active Storage Volume 41,000 gallons APPENDIX B Composting Facility Design Criteria Description Value Liner 30‐mil thick geomembrane Discharge rate 170 gpm Discharge pump One 7.5 hp submersible pump Discharge pipe 12‐inch diameter Screen Number 1 Type Trommel with Perkins 4 cylinder diesel engine Capacity 200 CY/hr (based on City experience) Mixer Number 1 Type Knight Reel Auggie 2450 Capacity 16 CY Front End Loader Number 1 Type V623 Versa Handler Capacity 2 CY bucket capacity Power 99 HP Appendix H City of Centralia National Pollutant Discharge Elimination System Waste Discharge Permit Page 1 of 41 Permit No. WA0020982 Issuance Date: March 28, 2011 Effective Date: May 1, 2011 Expiration Date: April 30, 2016 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM WASTE DISCHARGE PERMIT NO. WA0020982 State of Washington DEPARTMENT OF ECOLOGY Olympia, Washington 98504-7775 In compliance with the provisions of The State of Washington Water Pollution Control Law Chapter 90.48 Revised Code of Washington and The Federal Water Pollution Control Act (The Clean Water Act) Title 33 United States Code, Section 1342 et seq. City of Centralia 1100 North Tower Avenue Centralia, WA 98531 Plant Location: 1101 Goodrich Road, Centralia, WA 98531 Receiving Water: Chehalis River, Approximate River Mile 61.25 Water Body I.D. No.: Old ID No. WA-23- 1020, New ID No. 1238225469619 Discharge Location: Latitude: 46.76128 N Longitude: -123.02944W Plant Type: Extended Air Activated sludge with UV disinfection is authorized to discharge in accordance with the special and general conditions that follow. Steven G Eberl, P.E. Acting Southwest Regional Manager Water Quality Program Washington State Department of Ecology Page 2 of 41 Permit No. WA0020982 TABLE OF CONTENTS SUMMARY OF PERMIT REPORT SUBMITTALS .................................................................................. 4 SPECIAL CONDITIONS S1. DISCHARGE LIMITS .................................................................................................................... 5 A. Effluent Limits B. Mixing Zone Descriptions S2. MONITORING REQUIREMENTS ................................................................................................ 7 A. Monitoring Schedule B. Sampling and Analytical Procedures C. Flow Measurement S3. REPORTING AND RECORDING REQUIREMENTS ............................................................... 12 A. Reporting B. Recording of Results C. Additional Monitoring by the Permittee D. Notice of Noncompliance Reporting F. Other Noncompliance Reporting. G. Maintaining a Copy of This Permit S4. FACILITY LOADING .................................................................................................................. 14 A. Design Criteria B. Plans for Maintaining Adequate Capacity C. Duty to Mitigate D. Notification of New or Altered Sources E. Waste Load Assessment S5. OPERATION AND MAINTENANCE ......................................................................................... 16 A. Certified Operator B. O & M Program C. Short-term Reduction D. Electrical Power Failure E. Prevent Connection of Inflow F. Bypass Procedures G. Operations and Maintenance Manual S6. PRETREATMENT ........................................................................................................................ 20 A. General Requirements B. Wastewater Discharge Permit Required C. Identification and Reporting of Existing, New, and Proposed Industrial Users D. Annual Submittal of List of Industrial Users E. Duty to Enforce Discharge Prohibitions S7. RESIDUAL SOLIDS ..................................................................................................................... 22 S8. APPLICATION FOR PERMIT RENEWAL ................................................................................ 22 Page 3 of 41 Permit No. WA0020982 S9. RECEIVING WATER AND EFFLUENT STUDY OF TEMPERATURE, HARDNESS AND METALS ....................................................................................................................................... 22 S10. ACUTE TOXICITY ...................................................................................................................... 24 A. Testing When There Is No Permit Limit for Acute Toxicity B. Sampling and Reporting Requirements S11. CHRONIC TOXICITY A. Testing When There Is No Permit Limit for Chronic Toxicity B. Sampling and Reporting Requirements S12. OUTFALL EVALUATION .......................................................................................................... 28 S13. COPPER AND ZINC COMPLIANCE ......................................................................................... 28 GENERAL CONDITIONS G1. SIGNATORY REQUIREMENTS ................................................................................................. 29 G2. RIGHT OF INSPECTION AND ENTRY ..................................................................................... 30 G3. PERMIT ACTIONS....................................................................................................................... 30 G4. REPORTING PLANNED CHANGES .......................................................................................... 32 G5. PLAN REVIEW REQUIRED ....................................................................................................... 32 G6. COMPLIANCE WITH OTHER LAWS AND STATUTES ......................................................... 32 G7. TRANSFER OF THIS PERMIT ................................................................................................... 32 G8. REDUCED PRODUCTION FOR COMPLIANCE ...................................................................... 33 G9. REMOVED SUBSTANCES ......................................................................................................... 33 G10. DUTY TO PROVIDE INFORMATION ....................................................................................... 33 G11. OTHER REQUIREMENTS OF 40 CFR ....................................................................................... 33 G12. ADDITIONAL MONITORING .................................................................................................... 33 G13. PAYMENT OF FEES .................................................................................................................... 33 G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS.......................................................... 33 G15. UPSET ........................................................................................................................................... 34 G16. PROPERTY RIGHTS .................................................................................................................... 34 G17. DUTY TO COMPLY .................................................................................................................... 34 G18. TOXIC POLLUTANTS................................................................................................................. 34 G19. PENALTIES FOR TAMPERING ................................................................................................. 34 G20. REPORTING ANTICIPATED NON-COMPLIANCE ................................................................. 35 G21. REPORTING OTHER INFORMATION ...................................................................................... 35 G22. COMPLIANCE SCHEDULES ..................................................................................................... 35 G23. CONTRACT REVIEW ................................................................................................................. 35 Page 4 of 41 Permit No. WA0020982 SUMMARY OF PERMIT REPORT SUBMITTALS Refer to the Special and General Conditions of this permit for additional submittal requirements. Permit Section Submittal Frequency First Submittal Date S3. Discharge Monitoring Report Monthly June 15, 2011 S3.E Noncompliance Notification As necessary S4.B. Plans for Maintaining Adequate Capacity As necessary S4.D. Notification of New or Altered Sources As necessary S4.E. Wasteload Assessment Annually May 15, 2012 S5.G. Operations and Maintenance Manual As necessary S5.G. Operations and Maintenance Manual Update/Review Letter Annually March 15, 2012 S6.D. List of Industrial Users 1/permit cycle January 1, 2012 S8. Application for permit renewal 1/permit cycle November 1, 2015 S9. Receiving Water and Effluent Study Sampling and Quality Assurance Plan 1/permit cycle September 15, 2012 S9. Receiving Water and Effluent Sampling Reports 3/permit cycle December 15, 2013 December 15, 2014 December 15, 2015 S10.B. Acute Toxicity Effluent Test Results with Permit Renewal Application 2/permit cycle September 15, 2013, March 15, 2014, and November 1, 2015 S11.B Chronic Toxicity Effluent Test Results with Permit Renewal Application 2/permit cycle September 15, 2013, March 15, 2014, and November 1, 2015 S12. Outfall Evaluation 1/permit cycle September 15, 2011 S13. Copper and Zinc Reduction Activities Annually September 1, 2011 G1. Notice of Change in Authorization as necessary G4. Reporting Planned Changes As necessary G5. Engineering Report for Construction or Modification Activities As necessary G21. Reporting Anticipated Non-compliance As necessary G22. Reporting Other Information As necessary G23. Contract Submittal As necessary Page 5 of 41 Permit No. WA0020982 SPECIAL CONDITIONS In this permit the word must denotes an action that is mandatory and is equivalent to the word shall used in previous permits. S1. DISCHARGE LIMITS A. Effluent Limitations All discharges and activities authorized by this permit must comply with the terms and conditions of this permit. The discharge of any of the following pollutants more frequently than, or at a level in excess of, that identified and authorized by this permit constitutes a violation of the terms and conditions of this permit. Beginning on the effective date of this permit and lasting through the expiration of the permit, the Permittee may discharge municipal wastewater at the permitted location subject to compliance with the following limits: EFFLUENT LIMITSa: OUTFALL # 001 Parameter (at the River Flows Shown Belowf) Monthly Average Weekly Average Daily Maximumb BOD5 and TSS (flows < 200 cfs)c (flows 200 -- 1000 cfs)c 20 mg/L 20 mg/L 85% removal of influent BOD and TSS 30 mg/L, 826 lbs/day 30 mg/L, 926 lbs/day (flows > 1000 cfs) 30 mg/L, 925 lbs/day 75% removal of influent BOD 70% removal of influent TSS 45 mg/L, 2,530 lbs/day Ammonia (NH3-N) (March 15th – November 30th) (flows < 200 cfs)d 4.0 mg/L, 110 lbs/day (flows 200–<1000 cfs)d 4.0 mg/L, 123 lbs/day Ammonia (NH3-N) (December 1st - March 14th)d (flows 200–<1000 cfs)d 15 mg/L, 463 lbs/day Page 6 of 41 Permit No. WA0020982 EFFLUENT LIMITSa: OUTFALL # 001 Parameter (at the River Flows Shown Belowf) Monthly Average Weekly Average Daily Maximumb Ammonia (NH3-N) (flows >1000 cfs) 15 mg/L, 657 lbs/day The following parameters apply to all flows and seasons Parameter Monthly Average Weekly Average Daily Maximum Fecal coliform 200 col/100 ml 400 col/100 ml Copperg Zincg pHe Daily minimum is equal to or greater than 6.0 and the daily maximum is less than or equal to 9.0. a The average monthly and weekly effluent limitations equal the arithmetic mean of the samples taken. The average monthly and weekly limitations for fecal coliform are equal to the geometric mean of the samples taken. b The maximum daily effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day. This does not apply to pH. c These “dry weather” limits (for BOD & TSS only) apply on the next day after the 7-day moving average flow at the Grand Mound USGS gage goes below 1,000 cfs and on all subsequent days until the wet weather limits apply. d These “dry weather” limits (for ammonia only) go into effect 14 days after the seven-day moving average flow at the Grand Mound USGS gage is less than 1,000 cfs. This dry weather limit for ammonia cannot be applied earlier than March 15 of each year following the 14-day phase in. e Indicates the range of permitted values. The Permittee must report the instantaneous maximum and minimum pH monthly. Do not average pH values. f River flows must be determined from the Grand Mound USGS gage. g Ecology will recalculate final limits for copper in 2015 using water quality data collected by the discharger (see Section S9). Should a condition arise where the Permittee is unable to use UV light disinfection, the Permittee is authorized to use chlorine as a final disinfectant on a limited emergency basis. During periods when chlorine use is necessary, the Permittee shall conform to a total residual chlorine discharge limit of 0.5 mg/L monthly average and 0.75 mg/L weekly average. The limit will remain in effect until such time as UV disinfection has been restored. Page 7 of 41 Permit No. WA0020982 B. Mixing Zone Descriptions The following paragraph defines the maximum boundaries or flow-volume restriction of the mixing zones: Chronic Mixing Zone Washington Administrative Code (WAC) 173-201A-400(7)(a)(i) specifies that mixing zones must not extend downstream from the discharge ports for a distance of more than 300 feet plus the depth of water over the discharge ports as measured during the 7Q10 seasonal low flow and must not extend upstream more than one hundred feet. Given a 7Q10 water depth of 5 feet for the Permittee's outfall, the mixing zone boundary is limited to 305 feet downstream and 100 feet upstream from the discharge ports. The maximum width of the mixing zone is limited to not more than 25 percent of the flow and not more than 25 percent of the width of the water body. Therefore, the maximum flow at the 7Q10 flow is limited to 28.5 cfs (18.4 mgd). Because the river width is 160 feet wide at low flow, the maximum plume width is limited to 40 feet. Chronic aquatic life criteria and human health criteria must be met at the edge of the chronic zone. Acute Mixing Zone WAC 173-201A-400(8)(a) specifies that in riverine waters a zone where acute criteria may be exceeded must not extend beyond 10 percent of the distance established for the maximum or chronic zone as measured independently from the discharge ports. The acute mixing zone is therefore limited to 30.5 feet downstream, ten feet upstream and no more than 4 feet wider than the maximum width measured from the center of each discharge port. The mixing zone extends from the riverbed to the top of the water surface. Acute aquatic life criteria must be met at the edge of the acute zone. Available Dilution (dilution factor) Acute Aquatic Life Criteria 2.2 Chronic Aquatic Life Criteria 16 Human Health Criteria - Carcinogen 48 Human Health Criteria - Non-carcinogen 17.4 S2. MONITORING REQUIREMENTS A. Monitoring Schedule The Permittee must monitor in accordance with the following schedule: Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Wastewater Influent BOD5 mg/L lbs/day Influent Sampler 3/week 24-hour composite Page 8 of 41 Permit No. WA0020982 Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Wastewater Influent TSS mg/L lbs/day Influent Sampler 3/week 24-hour composite Wastewater Influent pH S.U. Influent Sampler Daily Grab Wastewater Influent Temperatureb ºC Influent Continuousa recording Wastewater Influent Flow mgd Influent mag. meter Continuous On-line recording Wastewater Effluent Flow mgd Effluent Parshall flume Continuous On-line recording Wastewater Effluent BOD5 mg/L Following post aeration 3/week 24-hour composite Wastewater Effluent BOD5 lbs/day Following post aeration 3/week Calculation Wastewater Effluent BOD5 % removal Following post aeration 3/week Calculation Wastewater Effluent TSS mg/L Following post aeration 3/week 24-hour composite Wastewater Effluent TSS lbs/day Following post aeration 3/week Calculation Wastewater Effluent TSS % removal Following post aeration 3/week Calculation Wastewater Effluent pH Standard Units Following post aeration Daily Grab Wastewater Effluent Temperatureb °C (report 10ths of a degree) Post aeration or at outfall vent Continuous Recording Wastewater Effluent Fecal Coliform Org./100 mL Following post aeration 3/week Grab Wastewater Effluent Total Ammonia-(As NH3-N) mg/L Following post aeration 3/week 24-hour composite Wastewater Effluent Total Ammonia-(As NH3-N) lbs/day Following post aeration 3/week Calculation Page 9 of 41 Permit No. WA0020982 Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Wastewater Effluent Total Residual Chlorinec mg/L Following post aeration As Needed, Daily Grab Receiving Water and Effluent Study (See S9) Copper, Zinc, Silver, Lead, Mercury, pH, Hardness (influent and effluent), Soluble Reactive Phosphorus, Total Phosphorus, Total Nitrogen, and Dissolved Inorganic Nitrogen µg/L Effluent 2/month (2012-2014)d Metals with Clean grab, other parameters with grab Receiving Water (See S9) Copper, Zinc, Silver, Lead, Mercury, pH, Hardness (influent and effluent), Soluble Reactive Phosphorus, Total Phosphorus, Total Nitrogen, and Dissolved Inorganic Nitrogen µg/L Chehalis River upstream 2/month (2012-2014)d Metals with Clean grab, other parameters with grab Receiving Water Temperatureb ºC Chehalis River upstream 3/permit Recording Acute Toxicity Testing As specified in S10. Effluent 2/permit in last year prior to new permit application 24-hour composite Page 10 of 41 Permit No. WA0020982 Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Chronic Toxicity Testing As specified in S11. Effluent 2/permit in last year prior to new permit application 24-hour composite Reapplication Monitoring to be Completed Prior to Application Submittal Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Reapplication Monitoring Dissolved Oxygen mg/L Effluent 1/year Grab Reapplication Monitoring Oil and Grease mg/L Effluent 1/year Grab Reapplication Monitoring Total Dissolved Solids mg/L Effluent 1/year 24-hour composite Reapplication Monitoring EPA Priority Pollutants - metals, cyanide and total phenols. 1M-15M µg/L Effluent 1/year 24-hour composite Reapplication Monitoring EPA Priority Pollutants – Volatile Organic Compounds. 1V – 31V µg/L Effluent 1/year 24-hour composite Reapplication Monitoring EPA Priority Pollutants – Acid- extractable compounds 1A – 11A µg/L Effluent 1/year 24-hour composite Reapplication Monitoring EPA Priority Pollutants – Base-neutral compounds 1B – 46B µg/L Effluent 1/year 24-hour composite a Continuous means uninterrupted except for brief lengths of time for calibration, for power failure, or for unanticipated equipment repair or maintenance. The Permittee must sample daily when continuous monitoring is not possible. Page 11 of 41 Permit No. WA0020982 Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type b Temperature must be measured continuously. A daily maximum must be determined and reported from half-hour measurements in a 24-hour period. If continuous thermister problems are temporarily unavailable, then sample temperature daily with a grab. Sampling must occur when the effluent is at or near its daily maximum temperature which will usually be in the late afternoon. c In the event that chlorine use is required for disinfection, the Permittee shall monitor the final effluent for total residual chlorine concentrations. This monitoring shall be conducted with grab sampling, to be performed each day that chlorine is being used. d Monthly sampling must occur in June, July, September and October of each year from 2012 -2014. B. Sampling and Analytical Procedures Samples and measurements taken to meet the requirements of this permit must be representative of the volume and nature of the monitored parameters. The Permittee must conduct representative sampling of any unusual discharge or discharge condition, including bypasses, upsets and maintenance-related conditions that may affect effluent quality. Sampling and analytical methods used to meet the monitoring requirements specified in this permit must conform to the latest revision of the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 Code of Federal Regulations (CFR) Part 136. C. Flow Measurement The Permittee must select and use appropriate flow measurement devices and methods consistent with accepted scientific practices. The Permittee must install, calibrate, and maintain the flow devices. This work is necessary to ensure that the accuracy of the measurements are consistent with the accepted industry standard and the manufacturers recommendation for that type of device. The Permittee must maintain calibration records for at least three years. D. Laboratory Accreditation The Permittee must ensure that all monitoring data required by the Department of Ecology (Ecology) is prepared by a laboratory registered or accredited under the provisions of Chapter 173-50 WAC, Accreditation of Environmental Laboratories. Flow, temperature, settleable solids, conductivity, pH, and internal process control parameters are exempt from this requirement. Conductivity and pH must be accredited if the laboratory must otherwise be registered or accredited. Ecology exempts crops, soils, and hazardous waste data from this requirement pending accreditation of laboratories for analysis of these media. Page 12 of 41 Permit No. WA0020982 S3. REPORTING AND RECORDING REQUIREMENTS The Permittee must monitor and report in accordance with the following conditions. Falsification of information submitted to Ecology is a violation of the terms and conditions of this permit. A. Reporting The first monitoring period begins on the effective date of the permit. The Permittee must submit monitoring results each month. The Permittee must summarize, report, and submit monitoring data obtained during each monitoring period on a DMR form provided, or otherwise approved, by Ecology. The Permittee must ensure that DMR forms are postmarked or received by Ecology no later than the 15th day of the month following the completed monitoring period, unless otherwise specified in this permit. The Permittee must submit priority pollutant analysis data no later than 45 days following the monitoring period. Unless otherwise specified, the Permittee must submit all toxicity test data within 60 days after the sample date. The Permittee must send report(s) to Ecology of Ecology, Southwest Regional Office, P.O. Box 47775, Olympia, Washington 98504- 7775. All laboratory reports providing data for organic and metal parameters must include the following information: sampling date, sample location, date of analysis, parameter name, CAS number, analytical method/number, method detection limit (MDL), laboratory practical quantitation limit (PQL), reporting units, and concentration detected. Analytical results from samples sent to a contract laboratory must include information on the chain of custody, the analytical method, QA/QC results, and documentation of accreditation for the parameter. The Permittee must submit DMR forms monthly whether or not the facility was discharging. If there was no discharge during a given monitoring period, the Permittee must submit the form as required with the words "no discharge" entered in place of the monitoring results. B. Recording of Results For each measurement or sample taken, the Permittee must record the following information: 1. The date, exact place, method, and time of sampling or measurement; 2. The individual who performed the sampling or measurement; 3. The dates the analyses were performed; 4. The individual who performed the analyses; 5. The analytical techniques or methods used; and 6. The results of all analyses. C. Additional Monitoring by the Permittee If the Permittee monitors any pollutant more frequently than required by Condition S2 of this permit, then the Permittee must include the results of such monitoring in the calculation and reporting of the data submitted in the Permittee's DMR. Page 13 of 41 Permit No. WA0020982 D. Notice of Noncompliance Reporting The Permittee must take the following action upon violation of any permit condition: Immediately take action to stop, contain, and cleanup unauthorized discharges or otherwise stop the noncompliance and correct the problem and, if applicable, immediately repeat sampling and analysis. The results of any repeat sampling must be submitted to Ecology within 30 days of sampling. 1. Immediate Noncompliance Notification Any failure of the disinfection system, must be reported immediately to Ecology's Regional Office 24-hour number 360-407-6300. Any failure of the disinfection system, any collection system overflows, or any plant bypass discharging to a waterbody used as a source of drinking water must be reported immediately to the Department of Ecology and the Department of Health, Drinking Water Program. The Department of Health’s Drinking Water Program number is 360-521-0323 (business hours) or 360-481-4901 (after business hours). 2. Twenty-four (24) Hour Noncompliance Notification The Permittee must report the following occurrences of noncompliance by telephone, to Ecology at 360-407-6300, within 24 hours from the time the Permittee becomes aware of any of the following circumstances: a. Any noncompliance that may endanger health or the environment, unless previously reported under subpart 1. above; b. Any unanticipated bypass that exceeds any effluent limitation in the permit (See Part S4.B., “Bypass Procedures”); c. Any upset that exceeds any effluent limitation in the permit (See G.15, “Upset”); d. Any violation of a maximum daily or instantaneous maximum discharge limitation for any of the pollutants in Section S1.A. of this permit; or e. Any overflow prior to the treatment works, whether or not such overflow endangers health or the environment or exceeds any effluent limitation in the permit. 3. Report Within Five (5) Days The Permittee must also provide a written submission within five days of the time that the Permittee becomes aware of any event required to be reported under subparts 1 or 2, above. The written submission must contain: a. A description of the noncompliance and its cause; b. The period of noncompliance, including exact dates and times; Page 14 of 41 Permit No. WA0020982 c. The estimated time noncompliance is expected to continue if it has not been corrected; d. Steps taken or planned to reduce, eliminate, and prevent recurrence of the noncompliance; and e. If the non compliance involves an overflow prior to the treatment works, an estimate of the quantity (in gallons) of untreated overflow. 4. Waiver of Written Reports Ecology may waive the written report required in subpart 3 above on a case-by-case basis upon request if a timely oral report has been received. 5. Report Submittal Reports must be submitted to the address in S3 (“REPORTING AND RECORDKEEPING REQUIREMENTS”). F. Other Noncompliance Reporting. The Permittee must report all instances of noncompliance, not required to be reported immediately or within 24 hours, at the time that monitoring reports for S3.A ("Reporting") are submitted. The reports must contain the information listed in paragraph E.3 above. Compliance with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply. The spill of oil or hazardous materials must be reported in accordance with the instructions obtained at the following website: http://www.ecy.wa.gov/programs/spills/other/reportaspill.htm G. Maintaining a Copy of This Permit The Permittee must keep a copy of this permit at the facility and make it available upon request to Department inspectors. S4. FACILITY LOADING A. Design Criteria The flows or waste loads for the permitted facility must not exceed the following design criteria: Average flow for the maximum month: 5.5 mgd Peak Daily Flow: 9.3 mgd BOD5 loading for maximum month: 4400 lbs/day TSS loading for maximum month: 4200 lbs/day Page 15 of 41 Permit No. WA0020982 B. Plans for Maintaining Adequate Capacity The Permittee must submit a plan and a schedule for continuing to maintain capacity to Ecology when: 1. The actual flow or waste load reaches 85 percent of any one of the design criteria in S4.A for three consecutive months; or 2. The projected increase would reach design capacity within five years, whichever occurs first. 3. The plan and schedule for continuing to maintain capacity must be sufficient to achieve the effluent limitations and other conditions of this permit. This plan must identify any of the following actions or any other actions necessary to meet the objective of maintaining capacity. a. Analysis of the present design including the introduction of any process modifications that would establish the ability of the existing facility to achieve the effluent limits and other requirements of this permit at specific levels in excess of the existing design criteria specified in paragraph A above. b. Reduction or elimination of excessive infiltration and inflow of uncontaminated ground and surface water into the sewer system. c. Limitation on future sewer extensions or connections or additional waste loads. d. Modification or expansion of facilities necessary to accommodate increased flow or waste load. e. Reduction of industrial or commercial flows or waste loads to allow for increasing sanitary flow or waste load. 4. Engineering documents associated with the plan must meet the requirements of WAC 173-240-060, "Engineering Report," and be approved by Ecology prior to any construction. 5. If the Permittee intends to apply for state or federal funding for the design or construction of a facility project, the plan must also meet the requirements of a “Facility Plan” as described in 40 CFR 35.2030. The plan must specify any contracts, ordinances, methods for financing, or other arrangements necessary to achieve this objective. C. Duty to Mitigate The Permittee must take all reasonable steps to minimize or prevent any discharge or sludge use or disposal in violation of this permit that has a reasonable likelihood of adversely affecting human health or the environment Page 16 of 41 Permit No. WA0020982 D. Notification of New or Altered Sources 1. The Permittee must submit written notice to Ecology whenever any new discharge or a substantial change in volume or character of an existing discharge into the Publicly Owned Treatment Works (POTW) is proposed which: a. Would interfere with the operation of, or exceed the design capacity of, any portion of the POTW; b. Is not part of an approved general sewer plan or approved plans and specifications; or c. Would be subject to pretreatment standards under 40 CFR Part 403 and Section 307(b) of the Clean Water Act. 2. This notice must include an evaluation of the POTW's ability to adequately transport and treat the added flow and/or waste load, the quality and volume of effluent to be discharged to the POTW, and the anticipated impact on the Permittee’s effluent [40 CFR 122.42(b)]. E. Wasteload Assessment 1. The Permittee must conduct an assessment of their flow and waste load and submit a report to Ecology by May 15, 2012, and annually thereafter. 2. The report must contain the following: an indication of compliance or noncompliance with the permit effluent limitations; a comparison between the existing and design monthly average dry weather and wet weather flows, peak flows, BOD, and total suspended solids loadings; and the percentage change in these parameters since the previous report. 3. The report must also state the present and design population or population equivalent, projected population growth rate, and the estimated date upon which the design capacity is projected to be reached, according to the most restrictive of the parameters above. 4. Ecology may modify the interval for review and reporting if it determines that a different frequency is sufficient. S5. OPERATION AND MAINTENANCE The Permittee must at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) that are installed to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance also includes keeping a daily operation logbook (paper or electronic), adequate laboratory controls and appropriate quality assurance procedures. This provision of the permit requires the Permittee to operate back- up or auxiliary facilities or similar systems only when the operation is necessary to achieve compliance with the conditions of this permit. Page 17 of 41 Permit No. WA0020982 A. Certified Operator This permitted facility must be operated by an operator certified by the state of Washington by the state of Washington for at least a Class III plant. This operator must be in responsible charge of the day-to-day operation of the wastewater treatment plant. An operator certified for at least a Class II plant must be in charge during all regularly scheduled shifts. B. O & M Program 1. The Permittee must institute an adequate operation and maintenance program for the entire sewage system. 2. The Permittee must keep maintenance records on all major electrical and mechanical components of the treatment plant, as well as the sewage system and pumping stations. Such records must clearly specify the frequency and type of maintenance recommended by the manufacturer and must show the frequency and type of maintenance performed. 3. The Permittee must make maintenance records available for inspection at all times. C. Short-term Reduction If a Permittee contemplates a reduction in the level of treatment that would cause a violation of permit discharge limitations on a short-term basis for any reason, and such reduction cannot be avoided, the Permittee must 1. Give written notification to Ecology, if possible, 30 days prior to such activities, 2. The notice must detail the reasons for, length of time of, and the potential effects of the reduced level of treatment. 3. This notification does not relieve the Permittee of its obligations under this permit. D. Electrical Power Failure The Permittee must ensure that adequate safeguards prevent the discharge of untreated wastes or wastes not treated in accordance with the requirements of this permit during electrical power failure at the treatment plant and/or sewage lift stations. Adequate safeguards include but are not limited to: alternate power sources, standby generator(s), or retention of inadequately treated wastes. For Reliability Class II - The Permittee must maintain Reliability Class II (EPA 430/9- 74-001) at the wastewater treatment plant; Reliability Class II requires a backup power source sufficient to operate all vital components and critical lighting and ventilation during peak wastewater flow conditions. Vital components used to support the secondary processes (i.e., mechanical aerators or aeration basin air compressors) need not be operable to full levels of treatment, but must be sufficient to maintain the biota. Page 18 of 41 Permit No. WA0020982 E. Prevent Connection of Inflow The Permittee must strictly enforce its sewer ordinances and not allow the connection of inflow (roof drains, foundation drains, etc.) to the sanitary sewer system. F. Bypass Procedures Bypass is the intentional diversion of waste streams from any portion of a treatment facility. This permit prohibits bypass. Ecology may take enforcement action against a Permittee for bypass unless one of the following circumstances (1, 2, or 3) is applicable. 1. Bypass is for essential maintenance without the potential to cause violation of permit limits or conditions. This permit authorizes a bypass if it allows for essential maintenance and does not have the potential to cause violations of limitations or other conditions of this permit, or adversely impact public health as determined by Ecology prior to the bypass. The Permittee must submit prior notice, if possible, at least ten (10) days before the date of the bypass. 2. Bypass is unavoidable, unanticipated and results in noncompliance with the conditions of this permit. This permit authorizes such a bypass only if: a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage. “Severe property damage” means substantial physical damage to property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. b. No feasible alternatives to the bypass exist, such as: • The use of auxiliary treatment facilities • Retention of untreated wastes • Stopping production • Maintenance during normal periods of equipment downtime, but not if adequate backup equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass, or • Transport of untreated wastes to another treatment facility c. The Permittee has properly notified Ecology of the bypass as required in condition S3.E of this permit. 3. If bypass is anticipated and has the potential to result in noncompliance of this permit. Page 19 of 41 Permit No. WA0020982 a. The Permittee must notify Ecology at least 30 days before the planned date of bypass. The notice must contain: i. A description of the bypass and its cause; ii. An analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing; iii. A cost-effectiveness analysis of alternatives including comparative resource damage assessment; iv. The minimum and maximum duration of bypass under each alternative; v. A recommendation as to the preferred alternative for conducting the bypass; vi. The projected date of bypass initiation; vii. A statement of compliance with State Environmental Policy Act (SEPA); viii. A request for modification of water quality standards as provided for in WAC 173-201A-410, if an exceedance of any water quality standard is anticipated; and ix. Details of the steps taken or planned to reduce, eliminate, and prevent reoccurrence of the bypass. b. For probable construction bypasses, the Permittee must notify Ecology of the need to bypass as early in the planning process as possible. The Permittee must consider the analysis required above during preparation of the engineering report or facilities plan and plans and specifications and must include these to the extent practical. In cases where the Permittee determines the probable need to bypass early, the Permittee must continue to analyze conditions up to and including the construction period in an effort to minimize or eliminate the bypass. c. Ecology will consider the following prior to issuing an administrative order for this type of bypass: i. If the bypass is necessary to perform construction or maintenance-related activities essential to meet the requirements of this permit. ii. If feasible alternatives to bypass exist, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production, maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility. iii. If the Permittee planned and scheduled the bypass to minimize adverse effects on the public and the environment. After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve or deny the request. The Page 20 of 41 Permit No. WA0020982 public will be given an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Ecology will approve of a request to bypass by issuing an administrative order under Revised Code of Washington (RCW) 90.48.120. G. Operations and Maintenance (O&M) Manual The Permittee must keep the approved O&M Manual available at the treatment plant and all operators must follow the instructions and procedures of this manual. The Permittee must review the O&M Manual at least annually and confirm this review by letter to Ecology by March 15, 2012, and annually thereafter. Whenever the Permittee makes substantial changes or updates to the O&M Manual the Permittee must submit the changes to Ecology. S6. PRETREATMENT A. General Requirements The Permittee must work with Ecology to ensure that all commercial and industrial users of the POTW comply with the pretreatment regulations in 40 CFR Part 403 and any additional regulations that may be promulgated under Section 307(b) (pretreatment) and 308 (reporting) of the Federal Clean Water Act. B. Wastewater Discharge Permit Required The Permittee must not allow any significant industrial users (SIUs) to discharge wastewater to the Permittee's sewer system until such user has received a wastewater discharge permit from Ecology in accordance with Chapter 90.48 RCW and Chapter 173-216 WAC. C. Identification and Reporting of Existing, New, and Proposed Industrial Users 1. The Permittee must take continuous, routine measures to identify all existing, new, and proposed SIUs and potential significant industrial users (PSIUs) discharging or proposing to discharge to the Permittee's sewer system (see Appendix B of the Fact Sheet for definitions). 2. Within 30 days of becoming aware of an unpermitted existing, new, or proposed industrial user who may be an SIU, the Permittee must notify such user by registered mail that, if classified as an SIU, they must apply to Ecology and obtain a State Waste Discharge Permit. The Permittee must send a copy of this notification letter to Ecology within this same 30-day period. 3. The Permittee must also notify all Potential SIUs (PSIUs), as they are identified, that if their classification should change to an SIU, they must apply to Ecology for a State Waste Discharge Permit within 30 days of such change. Page 21 of 41 Permit No. WA0020982 D. Annual Submittal of List of Industrial Users The Permittee must submit to Ecology a list summarizing all existing and proposed SIUs and PSIUs. The Permittee must submit this list to Ecology by January 1, 2012, and annually thereafter. E. Duty to Enforce Discharge Prohibitions 1. Under 40 CFR 403.5(a), the Permittee must not authorize or knowingly allow the discharge of any pollutants into its POTW which cause pass through or interference, or which otherwise violate general or specific discharge prohibitions contained in 40 CFR Part 403.5 or WAC-173-216-060. 2. The Permittee must not authorize or knowingly allow the introduction of any of the following into their treatment works: a. Pollutants which create a fire or explosion hazard in the POTW (including, but not limited to waste streams with a closed cup flashpoint of less than 140 degrees Fahrenheit or 60 degrees Centigrade using the test methods specified in 40 CFR 261.21). b. Pollutants which will cause corrosive structural damage to the POTW, but in no case discharges with pH lower than 5.0, or greater than 11.0 standard units, unless the works are specifically designed to accommodate such discharges. c. Solid or viscous pollutants in amounts that could cause obstruction to the flow in sewers or otherwise interfere with the operation of the POTW. d. Any pollutant, including oxygen demanding pollutants, (BOD, etc.) released in a discharge at a flow rate and/or pollutant concentration which will cause interference with the POTW. e. Petroleum oil, nonbiodegradable cutting oil, or products of mineral origin in amounts that will cause interference or pass through. f. Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity which may cause acute worker health and safety problems. g. Heat in amounts that will inhibit biological activity in the POTW resulting in interference but in no case heat in such quantities such that the temperature at the POTW headworks exceeds 40 degrees Centigrade (104 degrees Fahrenheit) unless Ecology, upon request of the Permittee, approves, in writing, alternate temperature limits. h. Any trucked or hauled pollutants, except at discharge points designated by the Permittee. Page 22 of 41 Permit No. WA0020982 i. Wastewaters prohibited to be discharged to the POTW by the Dangerous Waste Regulations (Chapter 173-303 WAC), unless authorized under the Domestic Sewage Exclusion (WAC 173-303-071). 3. This Permit prohibits all of the following from discharge to the POTW unless approved in writing by Ecology under extraordinary circumstances (such as a lack of direct discharge alternatives due to combined sewer service or the need to augment sewage flows due to septic conditions): a. Noncontact cooling water in significant volumes. b. Stormwater, and other direct inflow sources. c. Wastewaters significantly affecting system hydraulic loading, which do not require treatment, or would not be afforded a significant degree of treatment by the system. 4. The Permittee must notify Ecology if any industrial user violates the prohibitions listed in this section. S7. RESIDUAL SOLIDS Residual solids include screenings, grit, scum, primary sludge, waste activated sludge, and other solid waste. The Permittee must store and handle all residual solids in a manner that prevents their entry into state ground or surface waters. The Permittee must not discharge leachate from residual solids to state surface or ground waters. The Permittee shall comply with WAC 173-308 and any associated order for handling biosolids. S8. APPLICATION FOR PERMIT RENEWAL The Permittee must submit an application for renewal of this permit by November 1, 2015. S9. RECEIVING WATER AND EFFLUENT STUDY OF TEMPERATURE, HARDNESS AND METALS The Permittee must collect information on the effluent and receiving water to confirm that the effluent does or does not have a reasonable potential to cause a violation of the water quality standards. The Permittee must conduct chemical analyses of influent and effluent samples collected from the wastewater treatment system in accordance with protocols, monitoring requirements, and QA/QC procedures specified in this section. The Permittee must conduct sample analysis in accordance with 40 CFR Part 136. Quality Assurance Project Plan for metals and temperature: The Permittee must submit a sampling and quality assurance plan for temperature and metals monitoring for Ecology review and approval by September 15, 2012. The Permittee must conduct all sampling and analysis in accordance with the guidelines given in Guidelines for Preparing Quality Assurance Project Plans for Environmental Studies, Ecology Publication 04-03-030 (http://www.ecy.wa.gov/pubs/0403030.pdf). A model Quality Assurance Plan specific for temperature may be found at: http://www.ecy.wa.gov/programs/wq/permits/guidance.html. Page 23 of 41 Permit No. WA0020982 Temperature Sampling Temperature must be measured in the effluent and in the ambient water upstream of the outfall. Temperature must be measured at a minimum during the months of April through October of each year, beginning April 1, 2013, when flows are below 1,000 cfs in the receiving waters. Temperature must be monitored using micro-recording temperature devices known as thermistors. Ecology’s Quality Assurance Project Plan Development Tool (Continuous Temperature Sampling Protocols for the Environmental Monitoring and Trends) contains protocols for continuous temperature sampling. This document is available online at http://www.ecy.wa.gov/biblio/0503202.html. Calibration as specified in this document is not required if the Permittee uses recording devices which are certified by the manufacturer. Ecology does not require manufacture-specific equipment as given in this document; however, if the Permittee wishes to use measuring devices from another company the accuracy must be demonstrated to be equivalent. The recording devices must be set to record at one-half hour intervals. Temperature monitoring data must be reported as: daily maximum, seven-day running average of the daily maximums, and the monthly maximum of the seven-day running average. The model Quality Assurance Plan shows an example of these calculations. Temperature data from each April-October sampling period must be submitted to Ecology by December 15th of that year. Metals, Hardness, and Nutrient Sampling The Permittee shall sample and analyze the effluent and receiving water twice monthly during the critical season (June, July, August, September, and October) during the years 2013 through 2015 (inclusive) for the following parameters: Hardness (influent and effluent), pH, Copper, Zinc, Lead, Silver, and Mercury. The Permittee must follow the clean sampling techniques (Method 1669: Sampling Ambient Water for Trace Metals at EPA Water Quality Criteria Levels, EPA Publication No. 821-R-95-034, April 1995). The clean sampling techniques described in method 1669 are intended for ambient monitoring and must be modified for effluent sampling. All metals and hardness samples must be taken as grab samples. Clean sampling requires two samplers working as a team with; one sampler with “dirty hands” and another sampler with “clean hands.” The sampling station accuracy requirements are ± 20 meters. The receiving water sampling location must be outside the zone of influence of the effluent. All chemical analysis shall be conducted according to methods given in 40 CFR 136 and shall have the following detection levels: POLLUTANT PARAMETER METHOD DETECTION LIMIT REQUIRED (Total Recoverable) Copper (T) 200.8 1.0 μg/L Zinc (T) 200.8 2.0 μg/L Lead 200.8 1.0 mg/L Silver 200.8 0.1 mg/L Mercury 1631 c 0.2 ng/L Page 24 of 41 Permit No. WA0020982 Priority pollutant metals must be sampled and tested as total recoverable. The additional metals, that do not have listed minimum detection limits in the table above, require the Permittee to follow minimum detection levels according to the recommended testing procedures given in 40 CFR 136. Any subsequent sampling and analysis must also meet these requirements. The Permittee may conduct a cooperative receiving water study with other National Pollutant Discharge Elimination System (NPDES) Permittees discharging in the same vicinity. The Permittee must submit the results of the study to Ecology within 90 days of completing the effluent and receiving water studies. Nutrient Monitoring The Permittee must also monitor four key nutrient levels in both their effluent and the receiving stream and include these values in their annual report of monitoring. The parameters are Total Nitrogen, Dissolved Inorganic Nitrogen (DIN), Total Phosphorus, and Soluble and Reactive Phosphorus (SRP). The Permittee must collect samples twice monthly during the months of June through October (inclusively five months) in both the POTW’s effluent and in the river immediately upstream of the outfall. The Permittee must analyze these samples with a method sensitive enough to obtain quantifiable results. If levels are below the detection levels of the method employed, the Permittee shall use a more sensitive method for subsequent tests if such exits. For method listed under 40 CFR part 136, then the Permittee shall achieve that detection level or better. For Total Nitrogen, the Permittee may analyze the sample for Total Kjeldahl Nitrogen (TKN) and Nitrate-Nitrite (both of which are approved methods under 40 CFR part 136) and report the sum as total nitrogen. Two analytes, DIN and SRP, do not have approved methods, and the Permittee must ensure the laboratory uses appropriately sensitive analytical methods for these analytes. Sampling reports must be submitted which detail the results of the sampling. The Permittee must submit the first report by December 15, 2013, the second report by December 15, 2014, and the final report by December 15, 2015. The reports must contain the results of all sampling to date. S10. ACUTE TOXICITY A. Testing When There Is No Permit Limit for Acute Toxicity The Permittee must: • Conduct acute toxicity testing on final effluent during July 2013 and January 2014 (once in the last summer and once in the last winter prior to submission of the application for permit renewal). Resubmit the results to Ecology with the permit renewal application by November 1, 2015. • Conduct acute toxicity testing on a series of at least five concentrations of effluent, including 100 percent effluent and a control. • Use each of the following species and protocols for each acute toxicity test: 1. Fathead minnow, Pimephales promelas (96-hour static-renewal test, method: EPA-821-R-02-012). Page 25 of 41 Permit No. WA0020982 2. Daphnid, Ceriodaphnia dubia, Daphnia pulex, or Daphnia magna (48- hour static test, method: EPA-821-R-02-012). 3. Rainbow trout, Oncorhynchus mykiss (96-hour static-renewal test, method: EPA-821-R-02-012). B. Sampling and Reporting Requirements 1. The Permittee must submit all reports for toxicity testing in accordance with the most recent version of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. Reports must contain bench sheets and reference toxicant results for test methods. If the lab provides the toxicity test data in electronic format for entry into Ecology’s database, then the Permittee must send the data to Ecology along with the test report, bench sheets, and reference toxicant results. 2. The Permittee must collect 24-hour composite effluent samples or grab samples for toxicity testing. The Permittee must cool the samples to 0 - 6 degrees Celsius during collection and send them to the lab immediately upon completion. The lab must begin the toxicity testing as soon as possible but no later than 36 hours after sampling was completed. 3. The laboratory must conduct water quality measurements on all samples and test solutions for toxicity testing, as specified in the most recent version of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. 4. All toxicity tests must meet quality assurance criteria and test conditions specified in the most recent versions of the EPA methods listed in subsection C. and Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. If Ecology determines any test results to be invalid or anomalous, the Permittee must repeat the testing with freshly collected effluent. 5. The laboratory must use control water and dilution water meeting the requirements of the EPA methods listed in subsection A. or pristine natural water of sufficient quality for good control performance. 6. The Permittee must conduct whole effluent toxicity tests on an unmodified sample of final effluent. 7. The Permittee may choose to conduct a full dilution series test during compliance testing in order to determine dose response. In this case, the series must have a minimum of five effluent concentrations and a control. The series of concentrations must include the acute critical effluent concentration (ACEC). The ACEC equals 50 percent effluent. Page 26 of 41 Permit No. WA0020982 8. All whole effluent toxicity tests, effluent screening tests, and rapid screening tests that involve hypothesis testing must comply with the acute statistical power standard of 29 percent as defined in WAC 173-205-020. If the test does not meet the power standard, the Permittee must repeat the test on a fresh sample with an increased number of replicates to increase the power. 9. Reports of individual characterization or compliance test results must be submitted to Ecology within 60 days after each sample date. 10. The Acute Toxicity Summary Report for the summer sampling must be submitted to Ecology by September 15, 2013, and the winter sampling must be submitted by March 15, 2014. You must also resubmit the full test results to Ecology with the permit renewal application by November 1, 2015. S11. CHRONIC TOXICITY A. Testing When There Is No Permit Limit for Chronic Toxicity The Permittee must: • Conduct chronic toxicity testing on final effluent during July 2013 and January 2014 (once in the last summer and once in the last winter prior to submission of the application for permit renewal by December 1, 2014). • Submit the results to Ecology with the permit renewal application. • Conduct chronic toxicity testing on a series of at least five concentrations of effluent and a control. This series of dilutions must include the acute critical effluent concentration (ACEC). The ACEC equals 5 percent effluent. • Compare the ACEC to the control using hypothesis testing at the 0.05 level of significance as described in Appendix H, EPA/600/4-89/001. • Perform chronic toxicity tests with all of the following species and the most recent version of the following protocols: Freshwater Chronic Test Species Method Fathead minnow Pimephales promelas EPA-821-R-02-013 Water flea Ceriodaphnia dubia EPA-821-R-02-013 Page 27 of 41 Permit No. WA0020982 B. Sampling and Reporting Requirements 1. The Permittee must submit all reports for toxicity testing in accordance with the most recent version of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. Reports must contain bench sheets and reference toxicant results for test methods. If the lab provides the toxicity test data in electronic format for entry into Ecology’s database, then the Permittee must send the data to Ecology along with the test report, bench sheets, and reference toxicant results. 2. The Permittee must collect 24-hour composite effluent samples for toxicity testing. The Permittee must cool the samples to 0 - 6 degrees Celsius during collection and send them to the lab immediately upon completion. The lab must begin the toxicity testing as soon as possible but no later than 36 hours after sampling was completed. 3. The laboratory must conduct water quality measurements on all samples and test solutions for toxicity testing, as specified in the most recent version of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. 4. All toxicity tests must meet quality assurance criteria and test conditions specified in the most recent versions of the EPA methods listed in subsection C and Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. If Ecology determines any test results to be invalid or anomalous, the Permittee must repeat the testing with freshly collected effluent. 5. The laboratory must use control water and dilution water meeting the requirements of the EPA methods listed in subsection C. or pristine natural water of sufficient quality for good control performance. 6. The Permittee must conduct whole effluent toxicity tests on an unmodified sample of final effluent. 7. The Permittee may choose to conduct a full dilution series test during compliance testing in order to determine dose response. In this case, the series must have a minimum of five effluent concentrations and a control. The series of concentrations must include the CCEC and the ACEC. The CCEC and the ACEC may either substitute for the effluent concentrations that are closest to them in the dilution series or be extra effluent concentrations. The CCEC equals 8 percent effluent. The ACEC equals 50 percent effluent. 8. All whole effluent toxicity tests that involve hypothesis testing must comply with the chronic statistical power standard of 39 percent as defined in WAC 173-205- 020. If the test does not meet the power standard, the Permittee must repeat the test on a fresh sample with an increased number of replicates to increase the power. Page 28 of 41 Permit No. WA0020982 9. Reports of individual characterization or compliance test results must be submitted to Ecology within 60 days after each sample date. 10. The Chronic Toxicity Summary Report for the summer sampling must be submitted to Ecology by September 15, 2013, and the winter sampling must be submitted by March 15, 2014. You must also resubmit the full test results to Ecology with the permit renewal application by November 1, 2015. S12. OUTFALL EVALUATION The Permittee must inspect the submerged portion of the outfall line and diffuser once per permit to document its integrity and continued function. If conditions allow for a photographic verification, the Permittee must include such verification in the report. If there were problems found with the outfall, the report must recommend a solution and a schedule to fix the problem. The Permittee must submit a report on the condition of the outfall and solutions by September 15, 2011, to Ecology. If the Permittee finds significant integrity and functionality issues with the outfall, they must notify Ecology within 30 days of making that finding. S13. COPPER AND ZINC COMPLIANCE The Permittee must take ongoing actions to minimize the discharge of copper and zinc throughout the term of this permit. The Permittee must report annually on efforts to reduce metals levels in the effluent, which may include: • Control of supply water alkalinity and pH or other corrosion controls. • Optimizing the existing treatment processes. • Adding additional treatment to remove metals before discharge. • Identification and control of non-domestic metal sources. • Identifying reuse opportunities in lieu of disposal. Milestone Reporting Reporting Date Report on copper and zinc reduction activities September 1, 2011, and annually thereafter Page 29 of 41 Permit No. WA0020982 GENERAL CONDITIONS G1. SIGNATORY REQUIREMENTS A. All applications, reports, or information submitted to Ecology must be signed and certified. 1. In the case of corporations, by a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (i) A president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision making functions for the corporation, or (ii) the manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures. 2. In the case of a partnership, by a general partner. 3. In the case of sole proprietorship, by the proprietor. 4. In the case of a municipal, state, or other public facility, by either a principal executive officer or ranking elected official. Applications for permits for domestic wastewater facilities that are either owned or operated by, or under contract to, a public entity shall be submitted by the public entity. B. All reports required by this permit and other information requested by Ecology must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by a person described above and submitted to Ecology. 2. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility, such as the position of plant manager, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters. (A duly authorized representative may thus be either a named individual or any individual occupying a named position.) C. Changes to authorization. If an authorization under paragraph B.2 above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of paragraph B.2 Page 30 of 41 Permit No. WA0020982 above must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Certification. Any person signing a document under this section must make the following certification: I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. G2. RIGHT OF INSPECTION AND ENTRY The Permittee must allow an authorized representative of Ecology, upon the presentation of credentials and such other documents as may be required by law: A. To enter upon the premises where a discharge is located or where any records must be kept under the terms and conditions of this permit. B. To have access to and copy, at reasonable times and at reasonable cost, any records required to be kept under the terms and conditions of this permit. C. To inspect, at reasonable times, any facilities, equipment (including monitoring and control equipment), practices, methods, or operations regulated or required under this permit. D. To sample or monitor, at reasonable times, any substances or parameters at any location for purposes of assuring permit compliance or as otherwise authorized by the Clean Water Act. G3. PERMIT ACTIONS This permit may be modified, revoked and reissued, or terminated either at the request of any interested person (including the Permittee) or upon Ecology’s initiative. However, the permit may only be modified, revoked and reissued, or terminated for the reasons specified in 40 CFR 122.62, 40 CFR 122.64 or WAC 173-220-150 according to the procedures of 40 CFR 124.5. A. The following are causes for terminating this permit during its term, or for denying a permit renewal application: 1. Violation of any permit term or condition. 2. Obtaining a permit by misrepresentation or failure to disclose all relevant facts. Page 31 of 41 Permit No. WA0020982 3. A material change in quantity or type of waste disposal. 4. A determination that the permitted activity endangers human health or the environment, or contributes to water quality standards violations and can only be regulated to acceptable levels by permit modification or termination. 5. A change in any condition that requires either a temporary or permanent reduction, or elimination of any discharge or sludge use or disposal practice controlled by the permit. 6. Nonpayment of fees assessed pursuant to RCW 90.48.465. 7. Failure or refusal of the Permittee to allow entry as required in RCW 90.48.090. B. The following are causes for modification but not revocation and reissuance except when the Permittee requests or agrees: 1. A material change in the condition of the waters of the state. 2. New information not available at the time of permit issuance that would have justified the application of different permit conditions. 3. Material and substantial alterations or additions to the permitted facility or activities which occurred after this permit issuance. 4. Promulgation of new or amended standards or regulations having a direct bearing upon permit conditions, or requiring permit revision. 5. The Permittee has requested a modification based on other rationale meeting the criteria of 40 CFR Part 122.62. 6. Ecology has determined that good cause exists for modification of a compliance schedule, and the modification will not violate statutory deadlines. 7. Incorporation of an approved local pretreatment program into a municipality’s permit. C. The following are causes for modification or alternatively revocation and reissuance: 1. When cause exists for termination for reasons listed in A1 through A7 of this section, and Ecology determines that modification or revocation and reissuance is appropriate. 2. When Ecology has received notification of a proposed transfer of the permit. A permit may also be modified to reflect a transfer after the effective date of an automatic transfer (General Condition G8) but will not be revoked and reissued after the effective date of the transfer except upon the request of the new Permittee. Page 32 of 41 Permit No. WA0020982 G4. REPORTING PLANNED CHANGES The Permittee must, as soon as possible, but no later than 60 days prior to the proposed changes, give notice to Ecology of planned physical alterations or additions to the permitted facility, production increases, or process modification which will result in: 1) the permitted facility being determined to be a new source pursuant to 40 CFR 122.29(b); 2) a significant change in the nature or an increase in quantity of pollutants discharged; or 3) a significant change in the Permittee’s sludge use or disposal practices. Following such notice, and the submittal of a new application or supplement to the existing application, along with required engineering plans and reports, this permit may be modified, or revoked and reissued pursuant to 40 CFR 122.62(a) to specify and limit any pollutants not previously limited. Until such modification is effective, any new or increased discharge in excess of permit limits or not specifically authorized by this permit constitutes a violation. G5. PLAN REVIEW REQUIRED Prior to constructing or modifying any wastewater control facilities, an engineering report and detailed plans and specifications must be submitted to Ecology for approval in accordance with Chapter 173-240 WAC. Engineering reports, plans, and specifications must be submitted at least 180 days prior to the planned start of construction unless a shorter time is approved by Ecology. Facilities must be constructed and operated in accordance with the approved plans. G6. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in this permit must be construed as excusing the Permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations. G7. TRANSFER OF THIS PERMIT In the event of any change in control or ownership of facilities from which the authorized discharge emanate, the Permittee must notify the succeeding owner or controller of the existence of this permit by letter, a copy of which must be forwarded to Ecology. A. Transfers by Modification Except as provided in paragraph (B) below, this permit may be transferred by the Permittee to a new owner or operator only if this permit has been modified or revoked and reissued under 40 CFR 122.62(b)(2), or a minor modification made under 40 CFR 122.63(d), to identify the new Permittee and incorporate such other requirements as may be necessary under the Clean Water Act. B. Automatic Transfers This permit may be automatically transferred to a new Permittee if: 1. The Permittee notifies Ecology at least 30 days in advance of the proposed transfer date. Page 33 of 41 Permit No. WA0020982 2. The notice includes a written agreement between the existing and new Permittees containing a specific date transfer of permit responsibility, coverage, and liability between them. 3. Ecology does not notify the existing Permittee and the proposed new Permittee of its intent to modify or revoke and reissue this permit. A modification under this subparagraph may also be minor modification under 40 CFR 122.63. If this notice is not received, the transfer is effective on the date specified in the written agreement. G8. REDUCED PRODUCTION FOR COMPLIANCE The Permittee, in order to maintain compliance with its permit, must control production and/or all discharges upon reduction, loss, failure, or bypass of the treatment facility until the facility is restored or an alternative method of treatment is provided. This requirement applies in the situation where, among other things, the primary source of power of the treatment facility is reduced, lost, or fails. G9. REMOVED SUBSTANCES Collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of wastewaters must not be resuspended or reintroduced to the final effluent stream for discharge to state waters. G10. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all information which Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology upon request, copies of records required to be kept by this permit. G11. OTHER REQUIREMENTS OF 40 CFR All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference. G12. ADDITIONAL MONITORING Ecology may establish specific monitoring requirements in addition to those contained in this permit by administrative order or permit modification. G13. PAYMENT OF FEES The Permittee must submit payment of fees associated with this permit as assessed by Ecology. G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit is deemed guilty of a crime, and upon conviction thereof must be punished by a fine of up to $10,000 and costs of prosecution, or by imprisonment in the discretion of the court. Each day upon which a willful violation occurs may be deemed a separate and additional violation. Page 34 of 41 Permit No. WA0020982 Any person who violates the terms and conditions of a waste discharge permit will incur, in addition to any other penalty as provided by law, a civil penalty in the amount of up to $10,000 for every such violation. Each and every such violation is a separate and distinct offense, and in case of a continuing violation, every day's continuance is deemed to be a separate and distinct violation. G15. UPSET Definition – “Upset” means an exceptional incident in which there is unintentional and temporary noncompliance with technology-based permit effluent limitations because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. An upset constitutes an affirmative defense to an action brought for noncompliance with such technology-based permit effluent limitations if the requirements of the following paragraph are met. A Permittee who wishes to establish the affirmative defense of upset must demonstrate, through properly signed, contemporaneous operating logs, or other relevant evidence that: 1) an upset occurred and that the Permittee can identify the cause(s) of the upset; 2) the permitted facility was being properly operated at the time of the upset; 3) the Permittee submitted notice of the upset as required in condition S3.E; and 4) the Permittee complied with any remedial measures required under S4.C of this permit. In any enforcement action the Permittee seeking to establish the occurrence of an upset has the burden of proof. G16. PROPERTY RIGHTS This permit does not convey any property rights of any sort, or any exclusive privilege. G17. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. G18. TOXIC POLLUTANTS The Permittee must comply with effluent standards or prohibitions established under Section 307(a) of the Clean Water Act for toxic pollutants within the time provided in the regulations that establish those standards or prohibitions, even if this permit has not yet been modified to incorporate the requirement. G19. PENALTIES FOR TAMPERING The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required to be maintained under this permit must, upon conviction, be punished by a fine of not more than $10,000 per violation, or by Page 35 of 41 Permit No. WA0020982 imprisonment for not more than two years per violation, or by both. If a conviction of a person is for a violation committed after a first conviction of such person under this Condition, punishment must be a fine of not more than $20,000 per day of violation, or by imprisonment of not more than four years, or by both. G20. REPORTING ANTICIPATED NON-COMPLIANCE The Permittee must give advance notice to Ecology by submission of a new application or supplement thereto at least 180 days prior to commencement of such discharges, of any facility expansions, production increases, or other planned changes, such as process modifications, in the permitted facility or activity which may result in noncompliance with permit limits or conditions. Any maintenance of facilities, which might necessitate unavoidable interruption of operation and degradation of effluent quality, must be scheduled during noncritical water quality periods and carried out in a manner approved by Ecology. G21. REPORTING OTHER INFORMATION Where the Permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application, or in any report to Ecology, such facts or information must be submitted promptly. G22. COMPLIANCE SCHEDULES Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule of this permit must be submitted no later than 14 days following each schedule date. G23. CONTRACT REVIEW The Permittee must submit to Ecology any proposed contract for the operation of any wastewater treatment facility covered by this permit. The review is to insure consistency with chapters 90.46 and 90.48 RCW. In the event that Ecology does not comment within a 30-day period, the Permittee may assume consistency and proceed with the contract. Page 36 of 41 Permit No. WA0020982 APPENDIX A EFFLUENT CHARACTERIZATION FOR POLLUTANTS THIS LIST INCLUDES EPA REQUIRED POLLUTANTS (PRIORITY POLLUTANTS) AND SOME ECOLOGY PRIORITY TOXIC CHEMICALS (PBTs) The following table specifies analytical methods and levels to be used for effluent characterization in NPDES and State waste discharge permits. This appendix specifies effluent characterization requirements of the Department of Ecology unless other methods are specified in the body of this permit. This permit specifies the compounds and groups of compounds to be analyzed. Ecology may require additional pollutants to be analyzed within a group. The objective of this appendix is to reduce the number of analytical “non-detects” in permit-required monitoring and to measure effluent concentrations near or below criteria values where possible at a reasonable cost. If a Permittee knows that an alternate, less sensitive method (higher DL and QL) from 40 CFR Part 136 is sufficient to produce measurable results in their effluent, that method may be used for analysis. Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified CONVENTIONALS Biochemical Oxygen Demand SM5210-B 2 mg/L Chemical Oxygen Demand SM5220-D 10 mg/L Total Organic Carbon SM5310-B/C/D 1 mg/L Total Suspended Solids SM2540-D 5 mg/L Total Ammonia (as N) SM4500-NH3- GH 0.3 mg/L Flow Calibrated device Dissolved oxygen 4500-OC/OG 0.2 mg/L Temperature (max. 7-day avg.) Analog recorder or Use micro-recording devices known as thermistors 0.2º C pH SM4500-H+ B N/A N/A NONCONVENTIONALS Total Alkalinity SM2320-B 5 mg/L as CaCo3 Chlorine, Total Residual 4500 Cl G 50.0 Color SM2120 B/C/E 10 color unit Fecal Coliform SM 9221D/E,9222 N/A N/A Fluoride (16984-48-8) SM4500-F E 25 100 Nitrate-Nitrite (as N) 4500-NO3- E/F/H 100 Nitrogen, Total Kjeldahl (as N) 4500-NH3-C/E/FG 300 Page 37 of 41 Permit No. WA0020982 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Ortho-Phosphate (PO4 as P) 4500- PE/PF 3 10 Phosphorus, Total (as P) 4500-PE/PF 3 10 Oil and Grease (HEM) 1664A 1,400 5,000 Salinity SM2520-B 3 PSS Settleable Solids SM2540 -F 100 Sulfate (as mg/L SO4) SM4110-B 200 Sulfide (as mg/L S) 4500-S2F/D/E/G 200 Sulfite (as mg/L SO3) SM4500-SO3B 2000 Total dissolved solids SM2540 C 20 mg/L Total Hardness 2340B 200 as CaCO3 Aluminum, Total (7429-90-5) 200.8 2.0 10 Barium Total (7440-39-3) 200.8 0.5 2.0 Boron Total (7440-42-8) 200.8 2.0 10.0 Cobalt, Total (7440-48-4) 200.8 0.05 0.25 Iron, Total (7439-89-6) 200.7 12.5 50 Magnesium, Total (7439-95-4) 200.7 10 50 Molybdenum, Total (7439-98-7) 200.8 0.1 0.5 Manganese, Total (7439-96-5) 200.8 0.1 0.5 Tin, Total (7440-31-5) 200.8 0.3 1.5 METALS, CYANIDE & TOTAL PHENOLS Antimony, Total (7440-36-0) 200.8 0.3 1.0 Arsenic, Total (7440-38-2) 200.8 0.1 0.5 Beryllium, Total (7440-41-7) 200.8 0.1 0.5 Cadmium, Total (7440-43-9) 200.8 0.05 0.25 Chromium (hex) dissolved (18540-29-9) SM3500-Cr EC 0.3 1.2 Chromium, Total (7440-47-3) 200.8 0.2 1.0 Copper, Total (7440-50-8) 200.8 0.4 2.0 Lead, Total (7439-92-1) 200.8 0.1 0.5 Mercury, Total (7439-97-6) 1631E 0.0002 0.0005 Nickel, Total (7440-02-0) 200.8 0.1 0.5 Selenium, Total (7782-49-2) 200.8 1.0 1.0 Silver, Total (7440-22-4) 200.8 0.04 0.2 Thallium, Total (7440-28-0) 200.8 0.09 0.36 Zinc, Total (7440-66-6) 200.8 0.5 2.5 Cyanide, Total (57-12-5) 335.4 2 10 Cyanide, Weak Acid Dissociable SM4500-CN I 2 10 Phenols, Total EPA 420.1 50 DIOXIN 2,3,7,8-Tetra-Chlorodibenzo-P-Dioxin (176-40-16) 1613B 1.3 pg/L 5 pg/L Page 38 of 41 Permit No. WA0020982 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified VOLATILE COMPOUNDS Acrolein (107-02-8) 624 5 10 Acrylonitrile (107-13-1) 624 1.0 2.0 Benzene (71-43-2) 624 1.0 2.0 Bromoform (75-25-2) 624 1.0 2.0 Carbon tetrachloride (56-23-5) 624/601 or SM6230B 1.0 2.0 Chlorobenzene (108-90-7) 624 1.0 2.0 Chloroethane (75-00-3) 624/601 1.0 2.0 2-Chloroethylvinyl Ether (110- 75-8) 624 1.0 2.0 Chloroform (67-66-3) 624 or SM6210B 1.0 2.0 Dibromochloromethane (124- 48-1) 624 1.0 2.0 1,2-Dichlorobenzene (95-50-1) 624 1.9 7.6 1,3-Dichlorobenzene (541-73- 1) 624 1.9 7.6 1,4-Dichlorobenzene (106-46-7) 624 4.4 17.6 Dichlorobromomethane (75-27-4) 624 1.0 2.0 1,1-Dichloroethane (75-34-3) 624 1.0 2.0 1,2-Dichloroethane (107-06-2) 624 1.0 2.0 1,1-Dichloroethylene (75-35-4) 624 1.0 2.0 1,2-Dichloropropane (78-87-5) 624 1.0 2.0 1,3-dichloropropylene (mixed isomers) (542-75-6) 624 1.0 2.0 Ethylbenzene (100-41-4) 624 1.0 2.0 Methyl bromide (74-83-9) (Bromomethane) 624/601 5.0 10.0 Methyl chloride (74-87-3) (Chloromethane) 624 1.0 2.0 Methylene chloride (75-09-2) 624 5.0 10.0 1,1,2,2-Tetrachloroethane (79-34-5) 624 1.9 2.0 Tetrachloroethylene (127-18-4) 624 1.0 2.0 Toulene (108-88-3) 624 1.0 2.0 1,2-Trans-Dichloroethylene (156-60-5) (Ethylene dichloride) 624 1.0 2.0 1,1,1-Trichloroethane (71-55-6) 624 1.0 2.0 1,1,2-Trichloroethane (79-00-5) 624 1.0 2.0 Trichloroethylene (79-01-6) 624 1.0 2.0 Page 39 of 41 Permit No. WA0020982 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified Vinyl chloride (75-01-4) 624/SM6200B 1.0 2.0 ACID COMPOUNDS 2-Chlorophenol (95-57-8) 625 1.0 2.0 2,4-Dichlorophenol (120-83-2) 625 0.5 1.0 2,4-Dimethylphenol (105-67-9) 625 0.5 1.0 4,6-dinitro-o-cresol (534-52-1) (2-methyl-4,6,-dinitrophenol) 625/1625B 1.0 2.0 2,4 dinitrophenol (51-28-5) 625 1.0 2.0 2-Nitrophenol (88-75-5) 625 0.5 1.0 4-nitrophenol (100-02-7) 625 0.5 1.0 Parachlorometa cresol (59-50- 7) (4-chloro-3-methylphenol) 625 1.0 2.0 Pentachlorophenol (87-86-5) 625 0.5 1.0 Phenol (108-95-2) 625 2.0 4.0 2,4,6-Trichlorophenol (88-06-2) 625 2.0 4.0 BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs) Acenaphthene (83-32-9) 625 0.2 0.4 Acenaphthylene (208-96-8) 625 0.3 0.6 Anthracene (120-12-7) 625 0.3 0.6 Benzidine (92-87-5) 625 12 24 Benzyl butyl phthalate (85-68-7) 625 0.3 0.6 Benzo(a)anthracene (56-55-3) 625 0.3 0.6 Benzo(j)fluoranthene (205-82-3) 625 0.5 1.0 Benzo(r,s,t)pentaphene (189-55-9) 625 0.5 1.0 Benzo(a)pyrene (50-32-8) 610/625 0.5 1.0 3,4-benzofluoranthene (Benzo(b)fluoranthene) (205- 99-2) 610/625 0.8 1.6 11,12-benzofluoranthene (Benzo(k)fluoranthene) (207-08-9) 610/625 0.8 1.6 Benzo(ghi)Perylene (191-24-2) 610/625 0.5 1.0 Bis(2-chloroethoxy)methane (111-91-1) 625 5.3 21.2 Bis(2-chloroethyl)ether (111- 44-4) 611/625 0.3 1.0 Bis(2-chloroisopropyl)ether (39638-32-9) 625 0.3 0.6 Bis(2-ethylhexyl)phthalate (117-625 0.1 0.5 Page 40 of 41 Permit No. WA0020982 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified 81-7) 4-Bromophenyl phenyl ether (101-55-3) 625 0.2 0.4 2-Chloronaphthalene (91-58-7) 625 0.3 0.6 4-Chlorophenyl phenyl ether (7005-72-3) 625 0.3 0.5 Chrysene (218-01-9) 610/625 0.3 0.6 Dibenzo (a,j)acridine (224-42-0) 610M/625M 2.5 10.0 Dibenzo (a,h)acridine (226-36- 8) 610M/625M 2.5 10.0 Dibenzo(a-h)anthracene (53-70-3)(1,2,5,6-dibenzanthracene) 625 0.8 1.6 Dibenzo(a,e)pyrene (192-65-4) 610M/625M 2.5 10.0 Dibenzo(a,h)pyrene (189-64-0) 625M 2.5 10.0 3,3-Dichlorobenzidine (91-94-1) 605/625 0.5 1.0 Diethyl phthalate (84-66-2) 625 1.9 7.6 Dimethyl phthalate (131-11-3) 625 1.6 6.4 Di-n-butyl phthalate (84-74-2) 625 0.5 1.0 2,4-dinitrotoluene (121-14-2) 609/625 0.2 0.4 2,6-dinitrotoluene (606-20-2) 609/625 0.2 0.4 Di-n-octyl phthalate (117-84-0) 625 0.3 0.6 1,2-Diphenylhydrazine (as Azobenzene) (122-66-7) 1625B 5.0 20 Fluoranthene (206-44-0) 625 0.3 0.6 Fluorene (86-73-7) 625 0.3 0.6 Hexachlorobenzene (118-74-1) 612/625 0.3 0.6 Hexachlorobutadiene (87-68-3) 625 0.5 1.0 Hexachlorocyclopentadiene (77-47-4) 1625B/625 0.5 1.0 Hexachloroethane (67-72-1) 625 0.5 1.0 Indeno(1,2,3-cd)Pyrene (193-39-5) 610/625 0.5 1.0 Isophorone (78-59-1) 625 0.5 1.0 3-Methyl cholanthrene (56-49-5) 625 2.0 8.0 Naphthalene (91-20-3) 625 0.3 0.6 Nitrobenzene (98-95-3) 625 0.5 1.0 N-Nitrosodimethylamine (62-75-9) 607/625 2.0 4.0 N-Nitrosodi-n-propylamine 607/625 0.5 1.0 Page 41 of 41 Permit No. WA0020982 Pollutant & CAS No. (if available) Recommended Analytical Protocol Detection (DL)1 µg/L unless specified Quantitation Level (QL) 2 µg/L unless specified (621-64-7) N-Nitrosodiphenylamine (86- 30-6) 625 0.5 1.0 Perylene (198-55-0) 625 1.9 7.6 Phenanthrene (85-01-8) 625 0.3 0.6 Pyrene (129-00-0) 625 0.3 0.6 1,2,4-Trichlorobenzene (120-82-1) 625 0.3 0.6 PESTICIDES/PCBs Aldrin (309-00-2) 608 0.025 0.05 alpha-BHC (319-84-6) 608 0.025 0.05 beta-BHC (319-85-7) 608 0.025 0.05 gamma-BHC (58-89-9) 608 0.025 0.05 delta-BHC (319-86-8) 608 0.025 0.05 Chlordane (57-74-9) 608 0.025 0.05 4,4’-DDT (50-29-3) 608 0.025 0.05 4,4’-DDE (72-55-9) 608 0.025 0.0510 4,4’ DDD (72-54-8) 608 0.025 0.05 Dieldrin (60-57-1) 608 0.025 0.05 alpha-Endosulfan (959-98-8) 608 0.025 0.05 beta-Endosulfan (33213-65-9) 608 0.025 0.05 Endosulfan Sulfate (1031-07-8) 608 0.025 0.05 Endrin (72-20-8) 608 0.025 0.05 Endrin Aldehyde (7421-93-4) 608 0.025 0.05 Heptachlor (76-44-8) 608 0.025 0.05 Heptachlor Epoxide (1024-57- 3) 608 0.025 0.05 PCB-1242 (53469-21-9) 608 0.25 0.5 PCB-1254 (11097-69-1) 608 0.25 0.5 PCB-1221 (11104-28-2) 608 0.25 0.5 PCB-1232 (11141-16-5) 608 0.25 0.5 PCB-1248 (12672-29-6) 608 0.25 0.5 PCB-1260 (11096-82-5) 608 0.13 0.5 PCB-1016 (12674-11-2) 608 0.13 0.5 Toxaphene (8001-35-2) 608 0.24 0.5 1. Detection level (DL) or detection limit means the minimum concentration of an analyte (substance) that can be measured and reported with a 99% confidence that the analyte concentration is greater than zero as determined by the procedure given in 40 CFR part 136, Appendix B. 2. Quantitation Level (QL) is equivalent to EPA’s Minimum Level (ML) which is defined in 40 CFR Part 136 as the minimum level at which the entire GC/MS system must give recognizable mass spectra (background corrected) and acceptable calibration points. These levels were published as proposed in the Federal Register on March 28, 1997. Appendix I Reasonable Potential Analysis TECHNICAL MEMORANDUM 1 City of Centralia Wastewater General Sewer/Facility Plan – Reasonable Potential Analysis PREPARED FOR: City of Centralia COPY TO: Karla Kasick, Jacobs-CH2M PREPARED BY: Erin Thatcher, Jacobs-CH2M Brad Paulson, Jacobs-CH2M DATE: December 4, 2018; updated December 6, 2019 PROJECT NUMBER: 672413 REVIEWED BY: David Wilson, Jacobs-CH2M Jason Smesrud, Jacobs-CH2M Summary A reasonable potential analysis (RPA) was completed for the Centralia Wastewater Treatment Plant (WWTP) as part of the 2019 General Sewer Plan/Facility Plan. An RPA is used to determine whether a discharge has a reasonable potential to cause or contribute to a violation of Washington state water quality criteria for toxic pollutants. This RPA was requested by the Washington Department of Ecology (Ecology) in order to determine whether the WWTP effluent chemistry and updated dilution factors provide compliance with water quality criteria. An evaluation of temperature compliance was also completed. Ecology’s Permit Calculation worksheet (November 2016 version) was developed for the WWTP discharge using previously-established dilution factors for critical receiving water conditions, available effluent monitoring data, ambient Chehalis River temperature and chemistry data, and priority pollutant scan data from the past three years (2013 through 2015). This technical memorandum summarizes these data sources and results of the RPA. The Reasonable Potential Calculation spreadsheet is provided in Attachment A. Dilution factors at the designated mixing zone boundaries of the Centralia WWTP outfall have been updated using projected 2035 plant effluent flows, a most conservative approach. These updated dilution factors have been used to update the RPA for the Centralia WWTP. No reasonable potential to exceed water quality criteria were identified for ammonia or metals. No reasonable potential was identified for organic priority pollutants except for 18 organic compounds that are based solely on non-detected laboratory test results, and the compound bis-ethylhexyl phthalate (BEHP). Many of the water quality criteria (updated in December 2016) are below the lowest laboratory detection limits achieved by the priority pollutant scans. A reasonable potential for cyanide is based on a single detection in 2013 that used an incorrect analytical method for evaluating against water quality criteria. Reasonable potential calculations for temperature were completed based on river and effluent temperature monitoring data reported by the WWTP in 2013, 2014 and 2015 and updated dilution factors for project WWTP flows for 2035. Background river temperatures during summer low river flow conditions (May 16 to September 30) often exceed the salmon spawning, rearing and migration criteria CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 2 of 17.5° C in the Chehalis River. Using the updated dilution factor based on 2035 projected WWTP flows does not result in a reasonable potential determination for temperature during the summer low flow period. A reasonable potential was identified for temperature during the weeks of transition to the supplemental salmon spawning period (applicable October 1 to May 15). Temperature monitoring data also shows background Chehalis River temperatures periodically exceed the 13.0° C salmon spawning criteria during the spring and fall periods of transition to this salmon spawning period. The calculated incremental mixed temperature increase at the mixing zone boundary during the spring and fall transition periods to the salmon spawning period show temperature increases greater than 0.3° C, the maximum allowable incremental temperature increase. Background The Centralia WWTP discharges treated wastewater to the Chehalis River at river mile 61.25 through a 36-inch diameter outfall and multi-port diffuser that was constructed in 2003. The diffuser section begins approximately 35 to 40 feet off of the east bank (at low river flow) and the end gate structure of the diffuser is approximately 60 feet off of the west bank (at low river flow). Based on the latest outfall inspection completed in September 2015, the outfall is in very good condition and no repairs were needed. The City’s NDPES Permit (Permit No. WA0020982) was issued in 2011 and expired on April 30, 2016, and it is administratively extended until a new permit is issued. The City applied for permit renewal in December 2015, in accordance with the permit requirement, and a new permit has not yet been issued by Ecology. The previous permit established requirements for effluent and background receiving water monitoring for temperature and metals, which were completed by the City during 2013, 2014, and 2015. This monitoring established background temperature and background metals in the Chehalis River, as well as effluent metals concentrations, in order to evaluate the City’s WWTP effluent discharge with Washington State water quality criteria. The Chehalis River background temperature data were also collected to support Ecology’s implementation of the Chehalis River Total Maximum Daily Load (TMDL) for temperature. A total of 35 effluent and 35 background river samples were collected for analyses of metals and conventional pollutants over these three study years and reported by CH2M HILL in three annual reports (CH2M HILL 2013; 2014; 2015), hereinafter referred to as the Centralia Effluent and Receiving Water Study. The reasonable potential analysis (RPA) presented in this document was developed for the NPDES permit renewal based on the Centralia Effluent and Receiving Water Study and applicable Discharge Monitoring Report (DMR) data for 2013 - 2015. This RPA was completed as part of the General Sewer/Facility Plan currently being prepared for review and approval by Ecology. Data Sources and Assumptions The RPA was completed using Ecology’s Permit Calculation spreadsheet (November 2016 version) and is included in Attachment A. The RPA is based on the following data sources: • Centralia WWTP Effluent and Receiving Water Study (CH2M HILL 2013; 2014; 2015): effluent and background river pH, hardness, ammonia, copper, zinc, silver, lead, and mercury. • Semi-annual priority pollutant scans from July 2013, December 2013, June 2014, December 2014, October 2015, and November 2015: effluent metals and other toxics concentrations. • City of Centralia QAPP Temperature Study 2013, City of Centralia QAPP Temperature Study 2014, and City of Centralia QAPP Temperature Study 2015 (Microsoft Excel files provided to CH2M by the City): effluent and background river temperature. • Updated dilution factors calculated in February 2018 to reflect projected 2035 plant flows, as presented in the section below. CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 3 • The water quality criteria (human health and acute and chronic aquatic life criteria for freshwater) are from Chapter 173-201A-240 WAC Water Quality Standards for Washington. The RPA calculations here reflect revised human health criteria promulgated in late 2016, which include several federal human health criteria promulgated by the U.S. EPA for Washington state. Background (river) metals concentrations were analyzed as total recoverable metals in 2013, 2014, and 2015 data collections and as dissolved metals in 2015. Effluent metals concentrations were analyzed as total recoverable metals, in accordance with Sections S2.B and S9 in the NPDES Permit and 40 CFR 136. Background concentrations of other metals and organic pollutants that were not directly measured in the Chehalis River in the Centralia Effluent and Receiving Water Study, in accordance with the NPDES permit requirements, and are assumed to be 0 µg/L. Where metals were undetected in all samples, one- half of the laboratory’s detection limit was used in the reasonable potential calculation (occurred only for dissolved silver in the background river samples, 2015). Detection limits for mercury, copper, lead, and silver in the 2014 priority pollutant scan were higher than those used in the Centralia Effluent and Receiving Water Study. Silver (detection limit of 10 µg/L) and mercury (detection limit of 0.5 µg/L) were undetected at these higher reporting limits in the June and December 2014 priority pollutant scans. These reported non-detect results from the 2014 priority pollutant scan for silver and mercury were excluded from this RPA. Cadmium, chromium, copper, lead, nickel, silver, and zinc are hardness-dependent. The effluent and receiving water hardness values used in the reasonable potential calculations were the averages of the results of the 35 effluent samples and averages of the 35 receiving water samples collected during the Centralia Effluent and Receiving Water Study. Average effluent hardness based on these samples is 85.6 mg/L (as CaCO3), and the average receiving water hardness based on these samples is 31.2 mg/L (as CaCO3). Dilution Factors The reasonable potential analysis presented in the following sections is based on the dilution factors presented in Table 1. Previous reasonable potential calculations were based on the dilution factors specified in Section 1.B of the Centralia WWTP NPDES permit (issued 2011), which are: Aquatic Life, Acute: 2.2; Aquatic Life, Chronic: 16; Human Health, Carcinogen: 48; Human Health, Non-carcinogen: 17. Dilution factors for the Centralia WWTP outfall have been updated using projected 2035 plant effluent flows, which is a conservative approach. These dilution factors have been used to update the reasonable potential analysis (RPA) that was previously completed for the Centralia WWTP in May 2016, and this RPA will be included in the General Sewer/Facility Plan. The Water Quality Standards for the Surface Waters of the State of Washington (WAC 173-201A-400) specify that dilution in freshwater rivers and streams is restricted to defined acute and chronic mixing zones regions and is also limited based on available river flows. In rivers, the maximum chronic mixing zone boundary is 300 feet downstream from an outfall plus the depth of the outfall diffuser at 7Q10 river flow; and the acute mixing zone is limited to 10% of the chronic mixing zone size. These Water Quality Standards (WAC 173-201A-400) also specify the maximum ambient river flow that may be used in the calculation of dilution factors. The maximum river flow rate in rivers that can be utilized is 25 percent of the total river flow for the chronic mixing zone and volume-based dilution factors; and 2.5 percent of the total river flow for the acute mixing zone and volume-based dilution factor. Therefore, 7Q10 low river flow represents critical conditions that establish the river flow-based dilution restrictions. Under river flows greater than 7Q10 low river flow conditions, the dilution factors may be greater, but the mixing zone width and length restrictions remain the controlling limit to allowable dilution factors. Ecology’s Guidance for Conducting Mixing Zone Analyses (Appendix C of the Water Quality Program Permit Writer’s Manual; Ecology, 2015) specifies restrictions on the maximum ambient river flow that may be used in the calculation of dilution factors. As stated in this guidance document, the maximum CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 4 flow rate in non-tidally reversing rivers and streams that can be utilized by a chronic mixing zone is 25 percent of the total flow; and for an acute mixing zone, the maximum river flow rate that can be utilized is 2.5 percent of the total flow. The formulation of acute and chronic dilution factors for both aquatic life and human health water quality criteria involves solving the following volume-based equations: where DFmax_ is the maximum dilution factor allowed under acute and chronic conditions; Qamb is the critical flow rate of the receiving (ambient) water; and Qe is the critical effluent flow rate. The critical condition for the Chehalis River is the 7-day average low river flow with a recurrence interval of ten years (i.e., 7Q10). Additionally, the 30-day average low river flow with a recurrence interval of five years (i.e., 30Q5) and the harmonic mean (long term average) flows were used to develop dilution factors for evaluation of human health water quality criteria. These hydrologically-based design river flows were updated using the EPA program DFLOW1 (U.S. EPA, 1986). DFLOW requires input of daily stream flow records--such as those records from the systematic data collection program maintained by the USGS--and calculates user-specified biologically-based design flows, hydrologically-based design flows, harmonic and percentile flows. The 42-year record period from October 1975 to September 2017 using Chehalis River discharge data collected at USGS gaging station 12027500 located near Ground Mound, WA was used in this evaluation. Based on DFLOW results, these discharge data yielded critical river design flows for the 7Q10, 30Q5, and harmonic mean of 146 cfs, 185 cfs, and 668 cfs, respectively. Projected effluent flows for 2035 have been previously developed and, based on these future flow estimates, the highest daily maximum, highest monthly average, and the annual average projected 2035 flows are 10.70, 7.46, and 3.04 million gallons per day (mgd), respectively. Further, per Section 6-1 of the mixing zone guidance document, these effluent flows are to be used for determination of the maximum dilution factors for both aquatic life and human health water quality criteria. Based on the updated river and effluent flow information presented, dilution factors for the projected 2035 effluent flows are summarized in Table 1 below: Table 1. Dilution Factors and Assumptions for Centralia WWTP Projected 2035 Flows Water Quality Criteria Critical River Discharge Conditions Critical Effluent Conditions (Projected 2035) Volume-Based Dilution Factor Design Flow Flow (cfs) Flow Statistic Flow (mgd) Flow (cfs) Acute Chronic Aquatic Life 7Q10 146 Daily maximum 10.70 16.56 1.2 -- 7Q10 146 Monthly average 7.46 11.54 -- 4.2 Human Health— Carcinogen Harmonic mean 668 Annual average 3.04 4.70 -- 37 Human Health— Non- Carcinogen 30Q5 185 Annual average 3.04 4.70 -- 11 1 https://www.epa.gov/waterdata/dflow CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 5 Section 1.B of the existing NPDES permit specifies the limits of the acute and chronic mixing zone boundaries. Based on the mixing zone rules in the Water Quality Standards (WAC 173-201A-400), the renewed NPDES permit should define the Centralia WWTP mixing zones as: “limited to 305 feet downstream and 100 feet upstream from the discharge ports. The maximum width of the chronic mixing zone is limited to 25 percent of the width of the water body at low flow condition, or 40 feet based on the river width of 160 feet. The volume-based dilution factors are limited to 25 percent of the river flow under critical river discharge conditions for aquatic life and human health criteria. The acute mixing zone boundaries are limited to 30.5 feet downstream, ten feet upstream and no more than 40 feet width. The acute and chronic mixing zones extend from the riverbed to the top of the water surface.” Reasonable Potential Analysis Results Temperature Effluent and Background River Temperature Data The City obtained continuous effluent and background river water temperature data in the Chehalis River during the following low-flow periods: May 15, 2013 – October 31, 2013; June 3, 2014 – October 14, 2014; and April 28, 2015 – October 30, 2015. Effluent temperature data were also collected for similar periods in 2008 through 2012; these data are used again to evaluate future cooling or flow diversion needs. Only 2013-2015 temperature data were used for the reasonable potential calculation. Figure 1 below shows the Chehalis River temperature probe data and the effluent temperature for the entire paired river and effluent temperature dataset as 7-DADMax values, which is the 7-day average of the daily maximum recorded temperatures. The background Chehalis River temperature exceeded the effluent temperature during most of the summer period and during some weeks in the spring and fall periods of transition to the supplemental salmon spawning period (October 1 to May 15). Figure 1 shows that the effluent temperature was actually lower than the background river temperature during portions of the hottest summer months in 2013, 2014 and 2015. Temperature probe and Centralia WWTP outfall locations are shown on Figure 2. Temperature Reasonable Potential The applicable temperature criteria in the Chehalis River during the summer salmonid rearing and migration period (May 16 to September 30) is 17.5° C. As shown in Figure 1, the background Chehalis River temperatures exceed this criteria during the majority of the summer period; during this period an incremental temperature increase up to 0.3° C is allowed at the Centralia WWTP’s mixing zone boundary. No reasonable potential for temperatures to exceed the maximum allowable incremental temperature increase (0.3° C) was identified for critical conditions during the summer (May 16 to September 30) period, based on the updated chronic dilution factor of 4.2 at the mixing zone boundary and applicable effluent and river data from 2013-2015. See the reasonable potential calculation in Attachment A. The 95th-percentile 7-DADMax effluent temperature of 23.7° C and 90th-percentile 7-DADMax river temperature of 24.0° C were calculated from the maximum daily temperature data reported by the City for the summer low-flow periods (May 16 – September 30) in 2013, 2014 and 2015. The applicable temperature criteria in the Chehalis River during the supplemental salmon spawning period (October 1 to May 15) is 13.0° C. Applying the updated chronic dilution factor of 4.2 at the mixing zone boundary results in a worst-case maximum incremental temperature increase of 1.2° C during this period. See the temperature reasonable potential and limit calculation in Attachment A. This calculation used background river and effluent temperature data from only the transition periods for which background river temperature data were collected, which covered only a portion of the October 1 to May 15 time period each year of monitoring (2013, 2014, and 2015). These data periods included early October until the temperature probe in the river was removed, and early May through May 15 when it was re-deployed each year. A 7-DADMax effluent temperature (95th-percentile) of 18.1° C during this CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 6 transition period is required under the chronic worst-case conditions applied in the RPA to prevent an incremental increase of 0.3° C. The low chronic dilution factor of 4.2 is only applicable when river flows are at 7Q10 low flow conditions. Using the temperature reasonable potential calculation worksheet in Ecology’s PermitCalc tool, and assuming the same effluent flow and 7DADMax temperatures applied in the RPA, a dilution factor of 15 is needed during the supplemental spawning period (October 1 to May 15) to prevent an incremental temperature increase more than 0.3° C under the conservative effluent flow and temperature conditions applied in the RPA. A dilution factor of 15 can be achieved at river flows of 646 cfs and projected monthly maximum effluent flow of 11.54 cfs (see Table 1 above), according to the volume-based dilution factor equation: 𝐷𝐷𝐷𝐷max _𝑐𝑐ℎ𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑐𝑐=15 =(0.25 × 𝑄𝑄𝑎𝑎𝑎𝑎𝑎𝑎+𝑄𝑄𝑒𝑒)𝑄𝑄𝑒𝑒 𝑄𝑄𝑎𝑎𝑎𝑎𝑎𝑎=646 𝑐𝑐𝑐𝑐𝑐𝑐 During this supplemental spawning period, actual river flows in the Chehalis River range from 200 to 40,000 cfs. The actual recorded daily average river flow dropped below 646 cfs during this October 1 to May 15 period for the first few or several days during the transition period to the supplemental spawning period (see Figure 3). During the remaining majority of the supplemental spawning period, river flows are substantially higher than 646 cfs and provide more than enough dilution to prevent an incremental temperature increase greater than 0.3° C. Temperature Acute Lethality Acute lethality temperature barriers are also addressed in Chapter 173-201A WAC, (1)(c)(vii): (vii) The department will incorporate the following guidelines on preventing acute lethality and barriers to migration of salmonids into determinations of compliance with the narrative requirements for use protection established in this chapter (e.g., WAC 173-201A-310(1), 173-201A-400(4), and 173-201A-410 (1)(c)). The following site-level considerations do not, however, override the temperature criteria established for waters in subsection (1)(c) of this section or WAC 173-201A-602: (A) Moderately acclimated (16-20°C, or 60.8-68°F) adult and juvenile salmonids will generally be protected from acute lethality by discrete human actions maintaining the 7-DADMax temperature at or below 22°C (71.6°F) and the 1-day maximum (1-DMax) temperature at or below 23°C (73.4°F). (B) Lethality to developing fish embryos can be expected to occur at a 1-DMax temperature greater than 17.5°C (63.5°F). (C) To protect aquatic organisms, discharge plume temperatures must be maintained such that fish could not be entrained (based on plume time of travel) for more than two seconds at temperatures above 33°C (91.4°F) to avoid creating areas that will cause near instantaneous lethality. (D) Barriers to adult salmonid migration are assumed to exist any time the 1-DMax temperature is greater than 22°C (71.6°F) and the adjacent downstream water temperatures are 3°C (5.4°F) or cooler. The temperature limits of 22° C and 23° C for moderately acclimated salmon (see subsection A above) and 17.5° C for embryos (see subsection B above) are regularly exceeded by background river temperatures during the summer months. The effluent’s contribution to this exceedance was only calculated under critical conditions as defined in the reasonable potential analysis (see Attachment A). Additional analysis would be required to assess whether and how much the discharge contributes to the CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 7 exceedances under actual conditions. As described above, during much of the summer months, actual river flows remain above the 7Q10 low flow (see Figure 3), providing more dilution than the 4.2 dilution factor assumed in the reasonable potential calculation. The temperature limit of 33° C (see subsection C above) to prevent instantaneous lethality applies to all existing and proposed discharges. However, based on historical effluent temperature from the Centralia WWTP only being recorded as high as 24.4° C, this limitation should not require any modifications to current operations. The requirement to assess barriers to adult salmon migration (see subsection D above) requires analysis of additional river temperature data and was not included in this assessment. Future Effluent Cooling or Flow Diversion Needs Since the temperature limits are based on an allowable temperature increase at the mixing zone boundary, the limit is a function of both dilution flows and water temperature which represents a thermal wasteload allocation. The process for calculating the maximum allowable temperature increase was presented in the Water Quality Program Guidance Manual: Procedures to Implement the State’s Temperature Standards through NPDES Permits (Ecology, 2010): 𝑇𝑇𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁=[𝑇𝑇𝑟𝑟𝑐𝑐− 0.3oC]+[𝑐𝑐ℎ𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑐𝑐 𝑑𝑑𝑟𝑟𝑑𝑑𝑑𝑑𝑑𝑑𝑟𝑟𝑟𝑟𝑟𝑟 𝑐𝑐𝑓𝑓𝑐𝑐𝑑𝑑𝑟𝑟𝑟𝑟]∙0.3oC Where: chronic dilution factor = (Qeff + 0.25 x Q7Q10) / Qeff TNPDES = maximum allowable effluent temperature (°C) Trc = aquatic life temperature criteria (°C) Qeff = effluent flow (cfs) Q7Q10 = 7Q10 river flow (cfs) 0.25 = 25% by volume mixing zone allowance (unitless) When applied on a seasonal basis, maximum month effluent flows are used and consequently, the temperature limits can be excessively restrictive during lower flow periods. Applying the calculation as a flow-based limit requires continuous measurement of effluent and river flow but provides additional flexibility to adjust the temperature limits according to actual effluent flows. Both effluent and river flows are continuously measured at the WWTP and at the Grand Mound USGS gage, respectively. The mixing calculations presented above were applied to the daily effluent and river flow and effluent temperature data for the 2008 through 2015 calendar years to evaluate potential compliance issues that would have been encountered using a flow-based limit. The daily effluent temperatures and resulting temperature limits for effluent discharge to the river are presented in Figure 4. The calculated flow- based temperature limits were capped at 33 o C in accordance with the water quality standard limitations on maximum temperatures to prevent instantaneous lethality. This analysis shows that the effluent temperature limits would not have been exceeded in 2008 through 2014. In 2015, flow-based temperature limits would have been exceeded for most of August 2015; however, during this time the river flow drops below the calculated 7Q10 river flow. At river flows at or above the 7Q10, there would have been no exceedance of flow-based temperature limits in 2015. The flow-based limits were calculated using actual recorded daily average effluent flow data during 2008 through 2015. Some exceedances would be shown if effluent flows had been higher during these years. For example, if the 2008 through 2012 effluent flows were increased by 0.4 mgd, there would have been 14 days in October 2012 and 4 days in August 2009 during which the temperatures limits would have been exceeded. Further evaluation of temperature compliance needs and mitigation strategies under future conditions is planned to address potential temperature limitations as effluent flows increase. As shown in the evaluation above, some mitigation may be required at least during a portion of the transition into the supplemental spawning period (October 1 to May 15). One approach to thermal load compliance is partial diversion of effluent flow to irrigation or groundwater recharge. To establish requirements for CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 8 flow diversions or effluent cooling and appropriate design conditions will require additional statistical evaluation to correlate effluent flows with low river flows. An updated evaluation of temperature mitigation technologies such as irrigated reuse, discharge to constructed wetlands for ambient cooling, and groundwater recharge, including land availability/suitability and costs, will also be completed. pH The applicable pH criteria in the Chehalis River is within the range of 6.5 to 8.5, with a human-caused variation of less than 0.5 pH units within the range. The discharge will not cause a violation of water quality standards for pH. The average and maximum background Chehalis River pH was determined to be 7.48 and 7.97, respectively, based on the Centralia Effluent and Receiving Water Study. The average and maximum effluent pH from these studies was 6.97 and 7.30, respectively. The mixed effluent and river pH will limit the variation to less than 0.5 pH units within the range of 6.5 to 8.5. CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 9 Figure 1. Chehalis River Ambient Temperature and City of Centralia WWTP Effluent Temperature, 2013 – 2015 CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 10 Figure 2. Chehalis River Background Temperature Probe and City of Centralia WWTP Discharge Locations Figure 3. Chehalis River Flows During the Supplemental Spawning Period, Oct 1 – May 15 Chehalis River CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 11 Figure 4. 2008-2015 Analysis of Actual 7-DADM WWTP Effluent Temperatures and Projected Effluent Temperature Limits CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 12 Ammonia Based on this RPA, the Centralia WWTP discharge does not have a reasonable potential to violate water quality standards for ammonia. The Centralia WWTP has very efficient ammonia treatment processes. The 95th-percentile effluent ammonia concentration of 1.176 mg/L was calculated from DMR data and Centralia Effluent and Receiving Water Study data, 2013 - 2015. The background ammonia concentration of 0.036 mg/L was calculated from data obtained in the Centralia Effluent and Receiving Water Study. This is similar to the background ammonia concentration of 0.033 mg/L used in the RPA completed by Ecology during the previous permit cycle. Ecology requested the City also consider only river pH in the ammonia criteria calculation as a more conservative approach than using a mixed pH (Attachment B). In addition, Attachment B reflects the ammonia criteria calculations based on the 2015 max 7-DADMax river temp of 27.2° C. The results show that both approaches demonstrate the Centralia discharge complies with ammonia criteria. Metals In the previous permit, Ecology identified a reasonable potential to violate water quality criteria for copper, zinc, mercury, and silver, based on limited effluent and river chemistry data. Based on the established dilution factors and effluent and receiving water metals concentrations measured in 2013, 2014, and 2015, the City’s discharge does not have a reasonable potential to violate water quality criteria for any metals. The effluent and river metals data allowed the reasonable potential analysis to be prepared for antimony, arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc. Hexavalent chromium was tested for in the December 2014 priority pollutant analyses, and was undetected at a detection limit of 0.016 µg/L. Effluent metals concentrations were not analyzed in the December 2013 scan. See Attachment A for the reasonable potential calculations for each of these metals. Organic Pollutants Organic pollutants tested for in the 2013, 2014 and 2015 priority pollutant scans included a large suite of chemicals that includes volatile and semi-volatile organic compounds, pesticides and polychlorinated bi-phenyls (PCBs). In general, the lowest detection limits for organic pollutants were achieved in the 2015 priority pollutant scan. Assuming a concentration in the effluent of one-half of the lowest detection limit (from 2015) results in a reasonable potential determination for the organic pollutants listed below in Table 2, because the laboratory detection limits are higher than the applicable water quality criteria. The detection limits of these chemicals that were achieved in 2015 are consistent with, and in some cases exceed, the requirements of Appendix A of the Centralia WWTP’s current NPDES permit. Future priority pollutant scans may be able to achieve laboratory detection limits that can demonstrate water quality compliance for these chemicals. Table 2. Organic Priority Pollutants Identified With a Reasonable Potential Based On Non-Detect Test Results Priority Pollutant Lowest Laboratory Detection Limit (November 2015) Reasonable Potential Determinationa Applicable Water Quality Criteria Pesticides/PCBs Aldrin 0.0056 µg/L Chronic Aquatic Life, Human Health 0.0019 µg/L, 0.000000041 µg/L BHC – Alpha 0.0050 µg/L Human Health 0.000048 µg/L CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 13 Table 2. Organic Priority Pollutants Identified With a Reasonable Potential Based On Non-Detect Test Results Priority Pollutant Lowest Laboratory Detection Limit (November 2015) Reasonable Potential Determinationa Applicable Water Quality Criteria Chlordane 0.005 µg/L Human Health 0.000022 µg/L Dieldrin 0.0059 µg/L Chronic Aquatic Life, Human Health 0.0019 µg/L 0.00000007 µg/L 4,4-DDD 0.0073 µg/L Human Health 0.0000079 µg/L 4,4-DDE 0.0071 µg/L Chronic Aquatic Life, Human Health 0.001 µg/L, 0.00000088 µg/L 4,4-DDT 0.014 µg/L Chronic Aquatic Life, Human Health 0.001 µg/L, 0.0000012 Endrin 0.0074 µg/L Chronic Aquatic Life 0.0023 µg/L Heptachlor 0.0073 µg/L Chronic Aquatic Life, Human Health 0.0038 µg/L, 0.00000034 µg/L Heptachlor epoxide 0.0071 µg/L Chronic Aquatic Life, Human Health 0.0038 µg/L, 0.0000024 µg/L Toxaphene 0.35 µg/L Acute Aquatic Life, Chronic Aquatic Life, Human Health 0.73 µg/L, 0.0002 µg/L, 0.000032 µg/L Semi-Volatile Organic Compounds Benzo(a)anthracene 0.015 µg/L Human Health 0.00016 µg/L Benzo(b)fluoranthene 0.018 µg/L Human Health 0.00016 µg/L Benzo(a)pyrene 0.021 µg/L Human Health 0.000016 µg/L Benzidine 0.048 µg/L Human Health 0.00002 µg/L Dibenzo(a,h)anthracene 0.017 µg/L Human Health 0.000016 µg/L Hexachlorobenzene 0.023 µg/L Human Health 0.000005 µg/L Indeno(1,2,3-cd)pyrene 0.020 µg/L Human Health 0.00016 µg/L a Based on a concentration in the effluent assumed to be one-half of the detection limit. See calculations in Attachment A. Aldrin and heptachlor were detected in the effluent in a single priority pollutant sample prior to the 2011 permit. Aldrin and heptachlor are pesticides that are no longer in legal production or use in this area, and their presence would likely indicate legacy pollution from past land use. The current permit required that the City test for these pollutants during the current permit cycle. Aldrin and heptachlor were tested for in the 2010, 2011, 2014, and 2015 semi-annual priority pollutant scans for the Centralia WWTP. Neither were detected in any of these priority pollutant scans. The lowest laboratory detection limits for these two pollutants were achieved in 2015 and are listed above in Table 2. A reasonable potential was identified for bis-ethylhexyl phthalate (BEHP) based on the recently revised human health water quality criteria. BEHP was noted in the 2011 NPDES permit fact sheet as present possibly due to sample contamination, as this compound is a plasticizer that may be found in sampling equipment such as autosampler tubing and gloves. The maximum detected concentration of BEHP was 10 µg/L in December 2013, while no sample contamination was indicated by the laboratory quality control results. The recommended detection limit for BEHP in the permit’s Appendix A (0.1 ug/L) is CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 14 above the current human health limit of 0.045 ug/L (which triggered the reasonable potential). Recent analyses completed by the WWTP (2014, 2015) have resulted in non-detects of BEHP at a detection limit of 1.5 ug/L. As such, we recommend future testing requiring a detection limit below the human health criteria (and below that recommended in the NPDES permit), with an emphasis on QC procedures to address the potential for sample contamination. Reported effluent cyanide values were based on total cyanide analyses, which is not the correct method to use for evaluating against the water quality criteria. The water quality criteria for cyanide is based on weak acid dissociable cyanide instead of total cyanide. Total cyanide was detected at 0.012 mg/L in the July 2013 priority pollutant scan and the acute water quality standard for cyanide of 22 µg/L (for weak acid dissociable cyanide), higher than the maximum effluent value (12 µg/L). Total cyanide was undetected at a detection limit of 0.0015 mg/L in two samples in 2015. Toluene and di-n-butylphthalate were detected in the effluent at concentrations less than 1 µg/L, which is below the current human health water quality limits of 72 µg/L and 8 µg/L, respectively. As such, it was not necessary to complete the reasonable potential calculation for these two pollutants. Only those organic pollutants for which the water quality criteria are near or below the lowest achieved laboratory detection limit were evaluated in the reasonable potential calculations provided in Attachment A. Conclusions and Recommendations • No reasonable potential to cause or contribute to a violation of Washington’s current water quality criteria was identified for ammonia, metals, and the majority of the other priority pollutants in the Centralia WWTP discharge to the Chehalis River. This conclusion is based on the reasonable potential analysis developed with three years of comprehensive monitoring data (2013, 2014, and 2015) and dilution factors based on projected 2035 WWTP flows. A tentative reasonable potential determination was shown for 18 organic compounds based on non-detect laboratory test results. These chemicals are not expected to be present in the effluent. The detection limits of these chemicals that were achieved in 2015 are consistent with, and in some cases exceed, the requirements of Appendix A of the Centralia WWTP’s current NPDES permit (with the exception of toxaphene). • We recommend future testing for priority pollutants with detection limit below the human health criteria (and below that recommended in the NPDES permit), where possible, with an emphasis on QC procedures to address the potential for sample contamination. We recommend that the Centralia WWTP require contracted laboratories to test for weak acid dissociable cyanide in future priority pollutant scans to ensure compliance with water quality criteria. • The results of temperature compliance evaluations show the following: • Based on river and effluent temperature monitoring data reported by the City in 2013, 2014 and 2015 and updated dilution factors for project WWTP flows through 2035, a reasonable potential for excess temperature was identified during the weeks of transition from the summer spawning, rearing and migration criteria period (17.5° C) to the start of the supplemental salmon spawning period (13.0° C criteria applicable October 1 to May 15). • Further evaluation of temperature compliance needs and mitigation strategies under future conditions is planned to address potential temperature limitations as effluent flows increase. As shown in the evaluation above, some mitigation may be required at least during a portion of the transition into the supplemental spawning period (October 1 to May 15). CITY OF CENTRALIA WASTEWATER GENERAL SEWER/FACILITY PLAN – REASONABLE POTENTIAL ANALYSIS 15 References CH2M HILL. 2013. Receiving Water & Effluent Study of Metals and Hardness. Prepared for City of Centralia, Centralia Wastewater Treatment Plant, NPDES Permit No. WA0020982. December. CH2M HILL. 2014. Receiving Water & Effluent Study of Metals and Hardness. Prepared for City of Centralia, Centralia Wastewater Treatment Plant, NPDES Permit No. WA0020982. December. CH2M HILL. 2015. Receiving Water & Effluent Study of Metals and Hardness. Prepared for City of Centralia, Centralia Wastewater Treatment Plant, NPDES Permit No. WA0020982. December. U.S. Environmental Protection Agency. 1986. Technical guidance manual for performing wasteload allocation; Book VI, design conditions; Chapter 1, stream design flow for steady-state modeling. Office of Water Regulations and Standards, US Environmental Protection Agency. EPA Document PB92-231178. Washington State Department of Ecology (Ecology). 2010. Water Quality Program Guidance Manual: Procedures to Implement the State’s Temperature Standards through NPDES Permits. Publication #06- 10-100. Revised October 2010. Washington Department of Ecology (Ecology). 2011. Final Permit for NPDES Permit WA0020982, City of Centralia. Effective May 1, 2011. Fact Sheet for NPDES Permit WA0020982, City of Centralia. Effective May 1, 2011. Washington Department of Ecology (Ecology). 2015. Water Quality Program Permit Writer’s Manual. Publication No. 92-109. Revised January 2015. Attachments A Reasonable Potential Calculations (PermitCalc-Nov2016_Centralia2018.xls) B Reasonable Potential Calculations (Based on River pH) Attachment A Reasonable Potential Calculations (PermitCalc- Nov2016_Centralia2018.xls) Step 1: Enter Waterbody Type Facility Name Water Body Type Freshwater Receiving Water Step 2: Enter Dilution Factors -OR- Calculate DFs by entering Facility/Receiving Water Flow Data Do you want to enter dilution factors -or- flow data?Dilution Factors Annual Average Max Monthly Average Daily Max Facility Flow, MGD Facility Flow, cfs (calculated)0.00 0.00 0.00 Condition Receiving Water Flow, cfs Allowable % of river flow Max Dilution Factor Allowed Aquatic Life - Acute 7Q10 0.025 1.2 Aquatic Life - Chronic 7Q10 0.25 4.2 HH-Non-Carcinogen 30Q5 0.25 11.0 HH-Carcinogen Harmonic Mean 0.25 37.0 Whole river at 7Q10 7Q10 1 Step 3: Enter Critical Data Effluent Receiving Water Temp, °C 23.7 24 pH, s.u.6.97 7.48 Alkalinity, mg/L as CaCO3 Hardness, mg/L CaCO3 85.6 31.2 Salinity, psu Step 4: Specifiy if using 'Mixed' values for hardness, temperature, and pH Use 'Mixed Hardness' (Y/N) Use 'Mixed Max Temp' (Y/N) Use 'Mixed pH (Y/N) Y Y Y Acute Zone Boundary 76.5 23.8 #DIV/0! Chronic Zone Boundary 44.2 23.9 #DIV/0! Whole river at 7Q10 #VALUE!#VALUE!#VALUE! Receiving water TSS, mg/L (leave blank if unknown) If TSS is annual data, enter 'A'; if from critical period, enter 'S'; If no TSS, leave blank Dilution Factor Calculations and Receiving Water Critical Conditions Centralia WWTP Chehalis River Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 AMMONIA, Criteria as Total NH3ANTIMONY (INORGANIC) 7440360 1MARSENIC (dissolved) 7440382 2MBERYLLIUM 7440417 3MCADMIUM - 7440439 4M Hardness dependentCHROMIUM(TRI) -16065831 5M Hardness dependentCOPPER - 744058 6M Hardness dependentLEAD - 7439921 7M Dependent on hardnessMERCURY 7439976 8MNICKEL - 7440020 9M - Dependent on hardnessSELENIUM 7782492 10M267 6 6 6 6 6 40 40 38 6 6 3.1 0.6 0.6 0.6 0.6 0.6 0.5 1.2 1.4 0.6 0.6 1,176 0.53 0.58 0.07 0.088 0.76 9.24 0.83 0.00528 17 0.401 6.12 0.00168 36 0 0 0 1.23 0.08 0.00135 0 0 0 0.77 0.0006 0 0 Acute 13,684 -360 -2.77073 440.797 13.226 48.2098 2.1 1128.8 20 Chronic 1,113 -190 -0.56304 91.1275 5.64473 1.02276 0.012 78.7159 5 -6 ----1300 -0.14 80 60 Acute --1 -0.943 0.316 0.996 0.466 0.85 0.998 - Chronic --1 -0.943 0.86 0.996 0.466 -0.997 - N N Y Y N N N N N N N Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 1.537 0.555 0.555 0.555 0.555 0.555 0.472 0.944 1.042 0.555 0.555 Pn 0.989 0.607 0.607 0.607 0.607 0.607 0.928 0.928 0.924 0.607 0.607 1.00 2.14 2.14 2.14 2.14 2.14 1.00 1.00 1.00 2.14 2.14 Acute 986 0.946 1.035 0.125 0.148 0.429 7.874 0.336 0.004 30.280 0.716 Chronic 307 0.270 0.296 0.036 0.042 0.333 3.128 0.153 0.002 8.643 0.204 NO n/a NO n/a NO NO NO NO NO NO NO Aquatic Life Limit Calculation 3.1 0.6 0.6 0.6 0.6 0.6 0.5 1.2 1.4 0.6 0.6 3.1 0.6 0.6 0.6 0.6 0.6 0.5 1.2 1.4 0.6 0.6 Acute 16413.6 -432 -3.32488 528.957 15.6252 57.8357 2.51973 1354.57 24 Chronic 4560.72 -798 -2.36475 382.736 19.7719 4.03957 0.04608 330.607 21 Acute 1498.37 -138.708 -1.06756 169.839 5.82232 10.0422 0.38431 434.928 7.706 Chronic 641.363 -420.892 -1.24725 201.868 11.4944 1.29704 0.01295 174.373 11.0761 641.363 0 138.708 0 1.06756 169.839 5.82232 1.29704 0.01295 174.373 7.706 1.00 1.00 1.00 1.00 0.94 0.32 1.00 0.47 1.00 1.00 1.00 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 7025.7 0.0 432.0 0.0 3.5 1673.9 15.7 16.0 0.1 544.7 24.0 Human Health Reasonable Potential s 1.537 0.55451 0.55451 0.55451 0.55451 0.55451 0.47238 0.94446 1.04172 0.55451 0.55451 Pn 0.989 0.607 0.607 0.607 0.607 0.607 0.928 0.928 0.924 0.607 0.607 0.030 0.86028 0.86028 0.86028 0.86028 0.86028 0.50176 0.25188 0.22455 0.86028 0.86028 11 11 37 37 11 11 11 11 11 11 11 3.191 0.04145 0.01349 0.00163 0.00688 5.9E-02 1.3E+00 0.01901 0.0007 1.32952 0.03136 n/a NO n/a n/a n/a n/a NO n/a NO NO NO Human Health Limit Calculation 0 66 0 0 0 0 14292.3 0 1.534 880 660 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Centralia WWTP Freshwater Acute=76.5, Chronic=44.2 mg/L Aquatic Life Human Health Non-Carcinogenic Human Health Carcinogenic WQ Criteria for Protection of Human Health, ug/L Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? Pn=(1-confidence level)1/n s2=ln(CV2+1) Multiplier Dilution Factor Maximum Daily Limit (MDL), ug/L # of Compliance Samples Expected per month Waste Load Allocations, ug/L LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal s2=ln(CV2+1) Pn=(1-confidence level)1/n Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Effluent percentile value Reasonable Potential Calculation Long Term Averages, ug/L Effluent Data # of Samples (n) Effluent Concentration, ug/L (Max. or 95th Percentile) Pollutant, CAS No. & NPDES Application Ref. No. Aquatic Life Criteria, ug/L Carcinogen? Water Quality Criteria Coeff of Variation (Cv) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Metal Criteria Translator, decimal Maximum Daily Effluent Limit, ug/L Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 SILVER - 7740224 11M dependent on hardness. THALLIUM 7440280 12MZINC- 7440666 13M hardness dependentCYANIDE 57125 14MNITRATE/NITRITE (N)METHYLENE CHLORIDE 75092 22VPHENOL 108952 10ABIS(2-ETHYLHEXYL) PHTHALATE 117817 13BBENZIDINE 92875 4BALDRIN 309002 1PHEPTACHLOR 76448 16P38 4 40 6 35 6 6 5 1 1 1 0.7 0.6 0.4 0.6 0.2 0.6 0.6 0.6 0.6 0.6 0.6 0.03 0.064 79.4 12 4.1 0.995 10 0.024 0.0028 0.00365 59.7 23000 0.0125 3.2 0 0 0 0 3.2 0 225 0 0 0 0 0 0 Acute 2.17792 -91.2415 22 -----2.5 0.52 Chronic --52.2779 5.2 -----0.0019 0.0038 -1.7 1000 9 10000 10 9000 0.045 0.00002 4.1E-08 3.4E-07 Acute 0.85 -0.996 -------- Chronic --0.996 -------- N N N N N Y N Y Y Y Y Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.631 0.555 0.385 0.555 0.198 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.924 0.473 0.928 0.607 0.918 0.607 0.607 0.549 0.050 0.050 0.050 1.00 2.59 1.00 2.14 1.00 2.14 2.14 2.32 6.20 6.20 6.20 Acute 0.023 0.138 66.435 21.417 0.000 7.317 1.776 19.369 0.124 0.014 0.019 Chronic 0.017 0.039 21.267 6.119 0.000 2.091 0.507 5.534 0.035 0.004 0.005 NO n/a NO YES n/a n/a n/a n/a n/a YES YES Aquatic Life Limit Calculation 0.7 0.6 0.4 0.6 0.2 0.6 0.6 0.6 0.6 0.6 0.6 0.7 0.6 0.4 0.6 0.2 0.6 0.6 0.6 0.6 0.6 0.6 Acute 2.611 -108.85 26.4 -----3 0.624 Chronic ---209.327 21.84 -----0.00798 0.01596 Acute 0.73366 -47.8504 8.4766 -----0.96325 0.20036 Chronic ---134.675 11.5191 -----0.00421 0.00842 0.73366 0 47.8504 8.4766 0 0 0 0 0 0.00421 0.00842 0.85 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 3.1 0.0 109.3 26.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Human Health Reasonable Potential s 0.63149 0.55451 0.38525 0.55451 0.19804 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 Pn 0.924 0.473 0.928 0.607 0.918 0.607 0.607 0.549 0.050 0.050 0.050 0.40436 1.03846 0.56982 0.86028 0.75913 0.86028 0.86028 0.93363 2.48953 2.48953 2.48953 11 11 11 11 11 37 11 37 37 37 37 0.0011 0.00604 8.33636 0.93848 2295.45 9.5E-02 7.8E-02 0.25233 0.00161 0.00019 0.00025 n/a NO NO NO NO NO NO YES YES YES YES Human Health Limit Calculation 33 0 18.7 10968 99 107750 370 99000 1.665 0.00074 1.5E-06 1.3E-05 #DIV/0!#DIV/0!#DIV/0!261.191 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Metal Criteria Translator, decimal LTA Coeff. Var. (CV), decimal Multiplier Max concentration (ug/L) at edge of… Maximum Daily Limit (MDL), ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Reasonable Potential Calculation - Page 2 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Carcinogen? s2=ln(CV2+1) Pn=(1-confidence level)1/n Long Term Averages, ug/L Effluent percentile value Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? Average Monthly Effluent Limit, ug/L # of Compliance Samples Expected per month Maximum Daily Effluent Limit, ug/L Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 HEXACHLOROBENZENE 118741 33BPENTACHLOROPHENOL 87865 9A (pH dependent in freshwater)BENZO(a)ANTHRACENE 56553 5B3,3 DICHLOROBENZIDINE 91941 23BCHRYSENE 218019 18BBENZO(b)FLUORANTHENE 205992 7BBENZO(a)PYRENE 50328 6BINDENO(1,2,3-cd)PYRENE 193395 37BDIBENZO(a,h)ANTHRACENE 53703 19BACRYLONITRILE 107131 2VNITROSODIMETHYLAMINE N 62759 41B1 1 1 1 1 1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.0115 0.022 0.0075 0.0135 0.011 0.009 0.0105 0.01 0.0085 0.25 0.0044 0.022 0 0 0 0 0 0 0 0 0 0 0 0 Acute -#DIV/0!--------- Chronic -#DIV/0!--------- 5E-06 0.002 0.00016 0.0031 0.016 0.00016 1.6E-05 0.00016 1.6E-05 0.019 0.00065 Acute ----------- Chronic ----------- Y Y Y Y Y Y Y Y Y Y Y Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 Acute 0.059 0.114 0.039 0.070 0.057 0.046 0.054 0.052 0.044 1.291 0.023 Chronic 0.017 0.032 0.011 0.020 0.016 0.013 0.015 0.015 0.013 0.369 0.006 n/a #DIV/0!n/a n/a n/a n/a n/a n/a n/a n/a n/a Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute -#DIV/0!--------- Chronic -#DIV/0!--------- Acute -#DIV/0!--------- Chronic -#DIV/0!--------- 0 #DIV/0!0 0 0 0 0 0 0 0 0 1.00 #DIV/0!1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 0.0 #DIV/0!0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Human Health Reasonable Potential s 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 0.55451 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 2.48953 2.48953 2.48953 2.48953 2.48953 2.48953 2.48953 2.48953 2.48953 2.48953 2.48953 37 37 37 37 37 37 37 37 37 37 37 0.00077 0.00059 0.0005 0.00091 0.00074 6.1E-04 7.1E-04 0.00067 0.00057 0.01682 0.0003 YES NO YES NO NO YES YES YES YES NO NO Human Health Limit Calculation 0.00019 0.074 0.00592 0.1147 0.592 0.00592 0.00059 0.00592 0.00059 0.703 0.02405 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent percentile value Reasonable Potential? Limit Required? Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Maximum Daily Limit (MDL), ug/L # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Multiplier Max concentration (ug/L) at edge of… Dilution Factor Reasonable Potential Calculation - Page 3 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) WQ Criteria for Protection of Human Health, ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Long Term Averages, ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Pollutant, CAS No. & NPDES Application Ref. No. Max Conc. at edge of Chronic Zone, ug/L # of Compliance Samples Expected per month Reasonable Potential? Limit Required? Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Multiplier Instructions Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 BIS(2-CHLOROETHYL)ETHER 111444 11BN- NITROSODI-N-PROPYLAMINE 621647 42BDDT 50293 7PDDT METABOLITE (DDE) 72559 8PDDT METABOLITE (DDD) 72548 9PCHLORDANE 57749 6PBHC - ALPHA 319846 2PBHC - BETA 319857 3PBHC - DELTA 319868 5PHEPTACHLOR EPOXIDE 1024573 17PTOXAPHENE 8001352 25P1 1 1 1 1 1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.0185 0.012 0.007 0.0036 0.00037 0.0025 0.0025 0.0041 0.0028 0.0036 0.175 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Acute --1.1 1.1 1.1 2.4 ---0.52 0.73 Chronic --0.001 0.001 0.001 0.043 ane-Alpha ane-Beta -0.0038 0.0002 0.02 0.0044 1.2E-06 9E-07 7.9E-06 2.2E-05 4.8E-05 0.0013 -2E-06 3E-05 Acute ----------- Chronic ----------- Y Y Y Y Y Y Y Y Y Y Y Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 Acute 0.096 0.062 0.036 0.018 0.002 0.013 0.013 0.021 0.014 0.018 0.904 Chronic 0.027 0.018 0.010 0.005 0.001 0.004 0.004 0.006 0.004 0.005 0.258 n/a n/a YES YES NO NO #VALUE!######n/a YES YES Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute --1.32 1.32 1.32 2.88 ---0.624 0.876 Chronic --0.0042 0.0042 0.0042 0.1806 #VALUE!######-0.016 0.0008 Acute --0.42383 0.4238 0.42383 0.92472 ---0.2004 0.2813 Chronic --0.00222 0.0022 0.00222 0.09525 #VALUE!######-0.0084 0.0004 0 0 0.00222 0.0022 0.00222 0.09525 #VALUE!######0 0.0084 0.0004 1.00 1.00 1.00 1.00 1.00 1.00 #VALUE!######1.00 1.00 1.00 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#VALUE!#######DIV/0!#DIV/0!#DIV/0! 0.0 0.0 0.0 0.0 0.0 0.3 #VALUE!######0.0 0.0 0.0 Human Health Reasonable Potential s 0.5545 0.5545 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 2.4895 2.4895 2.48953 2.4895 2.48953 2.48953 2.48953 2.4895 2.4895 2.4895 2.4895 37 37 37 37 37 37 37 37 37 37 37 0.0012 0.0008 0.00047 0.0002 2.5E-05 1.7E-04 1.7E-04 0.0003 0.0002 0.0002 0.0118 NO NO YES YES YES YES YES NO n/a YES YES Human Health Limit Calculation 0.74 0.1628 4.4E-05 3E-05 0.00029 0.00081 0.00178 0.0481 0 9E-05 0.0012 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 N N N N N N N N N N N N N N N N N N N N N N Reasonable Potential Calculation - Page 4 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent percentile value s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Long Term Averages, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Override formatting & show Aq. Life Limit Calc? Override formatting & show HH Limit Calc? Instructions Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 BENZO(k) FLUORANTHENE 207089 9BENDRIN 72208 14PENDRIN ALDEHYDE 7421934 15PDIELDRIN 60571 10P BENZO(k) FLUORANTHENE 207089 9BENDOSULFAN SULFATE 1031078 13PBHC - GAMMA 58899 4P (Lindane)2-CHLOROPHENOL 95578 1A1,3 DICHLOROBENZENE 541731 21B1,4 DICHLOROBENZENE 106467 22B1,2 DICHLOROBENZENE 95501 20B1 1 1 1 1 1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.01 0.0037 0.00415 0.003 0.01 0.00275 0.00325 0.014 0.0145 0.0145 0.0165 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Acute -0.18 -2.5 ------- Chronic -0.0023 -0.0019 -- a (lindane)---- 0.0016 0.002 0.034 7E-08 0.0016 9 0.43 15 2 200 700 Acute ----------- Chronic ----------- Y N N Y Y N Y N N N N Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 Acute 0.052 0.019 0.021 0.015 0.052 0.014 0.017 0.072 0.075 0.075 0.085 Chronic 0.015 0.005 0.006 0.004 0.015 0.004 0.005 0.021 0.021 0.021 0.024 n/a YES n/a YES n/a n/a #VALUE!n/a n/a n/a n/a Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute -0.216 -3 ------- Chronic -0.0097 -0.008 --#VALUE!---- Acute -0.0694 -0.9632 ------- Chronic -0.0051 -0.0042 --#VALUE!---- 0 0.0051 0 0.0042 0 0 #VALUE!0 0 0 0 1.00 1.00 1.00 1.00 1.00 1.00 #VALUE!1.00 1.00 1.00 1.00 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#VALUE!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 0.0 0.0 0.0 0.0 0.0 0.0 #VALUE!0.0 0.0 0.0 0.0 Human Health Reasonable Potential s 0.5545 0.5545 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 2.4895 2.4895 2.48953 2.4895 2.48953 2.48953 2.48953 2.4895 2.4895 2.4895 2.4895 37 11 11 37 37 11 37 11 11 11 11 0.0007 0.0008 0.00094 0.0002 0.00067 6.2E-04 2.2E-04 0.0032 0.0033 0.0033 0.0037 NO NO NO YES NO NO NO NO NO NO NO Human Health Limit Calculation 33 0.0592 0.022 0.374 3E-06 0.0592 99 15.91 165 22 2200 7700 #DIV/0!#DIV/0!#DIV/0!7E-06 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 N N N N N N N N N N N N N N N N N N N N N N Maximum Daily Effluent Limit, ug/L Override formatting & show Aq. Life Limit Calc? Override formatting & show HH Limit Calc? Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Long Term Averages, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent percentile value s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Max concentration (ug/L) at edge of… Reasonable Potential Calculation - Page 5 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Instructions Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 CHLOROISOPROPYL ETHER (BIS-2) 108601HEXACHLOROETHANE 67721 36BTRICHLOROBENZENE 1,2,4 120821 46BHEXACHLOROBUTADIENE 87683 34BBUTYLBENZYL PHTHALATE 85687 15B3,3 DICHLOROBENZIDINE 91941 23B1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.0175 0.0105 0.018 0.0055 0.0225 0.0135 0 0 0 0 0 0 0 0 0 0 0 Acute ------#N/A #N/A #N/A #N/A #N/A Chronic hyl) Ether -----#N/A #N/A #N/A #N/A #N/A 400 0.02 0.036 0.01 0.013 0.0031 #N/A #N/A #N/A #N/A #N/A Acute ------#N/A #N/A #N/A #N/A #N/A Chronic ------#N/A #N/A #N/A #N/A #N/A N Y -Y N Y #N/A #N/A #N/A #N/A #N/A Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 6.20 6.20 6.20 6.20 6.20 6.20 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Acute 0.090 0.054 0.093 0.028 0.116 0.070 #N/A #N/A #N/A #N/A #N/A Chronic 0.026 0.015 0.027 0.008 0.033 0.020 #N/A #N/A #N/A #N/A #N/A ######n/a n/a n/a n/a n/a #N/A #N/A #N/A #N/A #N/A Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute ------#N/A #N/A #N/A #N/A #N/A Chronic ######-----#N/A #N/A #N/A #N/A #N/A Acute ------#N/A #N/A #N/A #N/A #N/A Chronic ######-----#N/A #N/A #N/A #N/A #N/A ######0 0 0 0 0 #N/A #N/A #N/A #N/A #N/A ######1.00 1.00 1.00 1.00 1.00 #N/A #N/A #N/A #N/A #N/A #######DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#N/A #N/A #N/A #N/A #N/A ######0.0 0.0 0.0 0.0 0.0 #N/A #N/A #N/A #N/A #N/A Human Health Reasonable Potential s 0.5545 0.5545 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 2.4895 2.4895 2.48953 2.4895 2.48953 2.48953 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 11 37 37 37 11 37 #N/A #N/A #N/A #N/A #N/A 0.004 0.0007 0.00121 0.0004 0.00509 9.1E-04 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! NO NO NO NO NO NO #N/A #N/A #N/A #N/A #N/A Human Health Limit Calculation 33 4400 0.74 1.332 0.37 0.143 0.1147 #N/A #N/A #N/A #N/A #N/A #DIV/0!#DIV/0!#DIV/0!0.9762 #DIV/0!#DIV/0!#N/A #N/A #N/A #N/A #N/A Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 N N N N N N N N N N N N N N N N N N N N N N Reasonable Potential Calculation - Page 6 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent percentile value s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Override formatting & show Aq. Life Limit Calc? Override formatting & show HH Limit Calc? Waste Load Allocations, ug/L Long Term Averages, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Spawning/Rearing/Supplemental Migration Criteria INPUT May 16 - Sept 30 Oct 1 - May 15 1. Chronic Dilution Factor at Mixing Zone Boundary 4.2 4.2 2. 7DADMax Ambient Temperature (T) (Upstream Background 90th percentile)24.0 °C 16.7 °C 3. 7DADMax Effluent Temperature (95th percentile)23.7 °C 21.8 °C 4. Aquatic Life Temperature WQ Criterion in Fresh Water 17.5 °C 13.0 °C OUTPUT 5. Temperature at Chronic Mixing Zone Boundary:23.9 °C 17.9 °C 6. Incremental Temperature Increase or decrease:-0.1 °C 1.2 °C 7. Maximum Allowable Incremental Temperature Increase:0.3 °C 0.3 °C 8. Maximum Allowable Temperature at Mixing Zone Boundary:24.3 °C 17.0 °C A. If ambient temp is warmer than WQ criterion 9. Does temp fall within this warmer temp range?YES YES 10. Temperature Limit if Required:NO LIMIT 0.3 B. If ambient temp is cooler than WQ criterion but within 28/(Tamb+7) and within 0.3 °C of the criterion 11. Does temp fall within this incremental temp. range? ------ 12. Temp increase allowed at mixing zone boundary, if required:------ C. If ambient temp is cooler than (WQ criterion-0.3) but within 28/(Tamb+7) of the criterion 13. Does temp fall within this Incremental temp. range?------ 14. Temp increase allowed at mixing zone boundary, if required:------ D. If ambient temp is cooler than (WQ criterion - 28/(Tamb+7)) 15. Does temp fall within this Incremental temp. range?------ 16. Temp increase allowed at mixing zone boundary, if required:------ RESULTS 17. Do any of the above cells show a temp increase?NO YES 18. Temperature Limit if Required?NO LIMIT 14.0 °C Freshwater Temperature Reasonable Potential and Limit Calculation Based on WAC 173-201A-200(1)(c)(i)--(ii) and the Water Quality Program Guidance. All data inputs must meet WQ guidelines. The Water Quality temperature guidance document may be found at: https://fortress.wa.gov/ecy/publications/summarypages/0610100.html Attachment B Reasonable Potential Calculations (Based on River pH) Step 1: Enter Waterbody Type Facility Name Water Body Type Freshwater Receiving Water Step 2: Enter Dilution Factors -OR- Calculate DFs by entering Facility/Receiving Water Flow Data Do you want to enter dilution factors -or- flow data?Dilution Factors Annual Average Max Monthly Average Daily Max Facility Flow, MGD Facility Flow, cfs (calculated)0.00 0.00 0.00 Condition Receiving Water Flow, cfs Allowable % of river flow Max Dilution Factor Allowed Aquatic Life - Acute 7Q10 0.025 1.2 Aquatic Life - Chronic 7Q10 0.25 4.2 HH-Non-Carcinogen 30Q5 0.25 11.0 HH-Carcinogen Harmonic Mean 0.25 37.0 Whole river at 7Q10 7Q10 1 Step 3: Enter Critical Data Effluent Receiving Water Temp, °C 23.7 27.2 pH, s.u.7.3 7.97 Alkalinity, mg/L as CaCO3 Hardness, mg/L CaCO3 85.6 31.2 Salinity, psu Step 4: Specifiy if using 'Mixed' values for hardness, temperature, and pH Use 'Mixed Hardness' (Y/N) Use 'Mixed Max Temp' (Y/N) Use 'Mixed pH (Y/N) Y Y N Acute Zone Boundary 76.5 24.3 #DIV/0! Chronic Zone Boundary 44.2 26.4 #DIV/0! Whole river at 7Q10 #VALUE! #VALUE! #VALUE! Receiving water TSS, mg/L (leave blank if unknown) If TSS is annual data, enter 'A'; if from critical period, enter 'S'; If no TSS, leave blank Dilution Factor Calculations and Receiving Water Critical Conditions Centralia WWTP Chehalis River Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 AMMONIA, Criteria as Total NH3ANTIMONY (INORGANIC) 7440360 1MARSENIC (dissolved) 7440382 2MBERYLLIUM 7440417 3MCADMIUM - 7440439 4M Hardness dependentCHROMIUM(TRI) -16065831 5M Hardness dependentCOPPER - 744058 6M Hardness dependentLEAD - 7439921 7M Dependent on hardnessMERCURY 7439976 8MNICKEL - 7440020 9M - Dependent on hardnessSELENIUM 7782492 10M267 6 6 6 6 6 40 40 38 6 6 3.1 0.6 0.6 0.6 0.6 0.6 0.5 1.2 1.4 0.6 0.6 1,176 0.53 0.58 0.07 0.088 0.76 9.24 0.83 0.0053 17 0.401 6.12 0.0017 36 0 0 0 1.23 0.08 0.0014 0 0 0 0.77 0.0006 0 0 Acute 5,941 - 360 - 2.77073 440.797 13.226 48.21 2.1 1128.8 20 Chronic 589 - 190 - 0.56304 91.1275 5.64473 1.0228 0.012 78.716 5 - 6 - - - - 1300 - 0.14 80 60 Acute - - 1 - 0.943 0.316 0.996 0.466 0.85 0.998 - Chronic - - 1 - 0.943 0.86 0.996 0.466 - 0.997 - N N Y Y N N N N N N N Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 1.537 0.555 0.555 0.555 0.555 0.555 0.472 0.944 1.042 0.555 0.555 Pn 0.989 0.607 0.607 0.607 0.607 0.607 0.928 0.928 0.924 0.607 0.607 1.00 2.14 2.14 2.14 2.14 2.14 1.00 1.00 1.00 2.14 2.14 Acute 986 0.946 1.035 0.125 0.148 0.429 7.874 0.336 0.004 30.280 0.716 Chronic 307 0.270 0.296 0.036 0.042 0.333 3.128 0.153 0.002 8.643 0.204 NO n/a NO n/a NO NO NO NO NO NO NO Aquatic Life Limit Calculation 3.1 0.6 0.6 0.6 0.6 0.6 0.5 1.2 1.4 0.6 0.6 3.1 0.6 0.6 0.6 0.6 0.6 0.5 1.2 1.4 0.6 0.6 Acute 7122.2 - 432 - 3.32488 528.957 15.6252 57.836 2.5197 1354.6 24 Chronic 2360.6 - 798 - 2.36475 382.736 19.7719 4.0396 0.0461 330.61 21 Acute 650.17 - 138.708 - 1.06756 169.839 5.82232 10.042 0.3843 434.93 7.706 Chronic 331.97 - 420.892 - 1.24725 201.868 11.4944 1.297 0.0129 174.37 11.076 331.97 0 138.708 0 1.06756 169.839 5.82232 1.297 0.0129 174.37 7.706 1.00 1.00 1.00 1.00 0.94 0.32 1.00 0.47 1.00 1.00 1.00 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! 3636.4 0.0 432.0 0.0 3.5 1673.9 15.7 16.0 0.1 544.7 24.0 Human Health Reasonable Potential s 1.537 0.55451 0.55451 0.5545 0.55451 0.55451 0.47238 0.9445 1.0417 0.5545 0.5545 Pn 0.989 0.607 0.607 0.607 0.607 0.607 0.928 0.928 0.924 0.607 0.607 0.030 0.86028 0.86028 0.8603 0.86028 0.86028 0.50176 0.2519 0.2245 0.8603 0.8603 11 11 37 37 11 11 11 11 11 11 11 3.191 0.04145 0.01349 0.0016 0.00688 5.9E-02 1.3E+00 0.019 0.0007 1.3295 0.0314 n/a NO n/a n/a n/a n/a NO n/a NO NO NO Human Health Limit Calculation 0 66 0 0 0 0 14292.3 0 1.534 880 660 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Centralia WWTP Freshwater Acute=76.5, Chronic=44.2 mg/L Aquatic Life Human Health Non-Carcinogenic Human Health Carcinogenic WQ Criteria for Protection of Human Health, ug/L Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? Pn=(1-confidence level)1/n s2=ln(CV2+1) Multiplier Dilution Factor Maximum Daily Limit (MDL), ug/L # of Compliance Samples Expected per month Waste Load Allocations, ug/L LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal s2=ln(CV2+1) Pn=(1-confidence level)1/n Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Effluent percentile value Reasonable Potential Calculation Long Term Averages, ug/L Effluent Data # of Samples (n) Effluent Concentration, ug/L (Max. or 95th Percentile) Pollutant, CAS No. & NPDES Application Ref. No. Aquatic Life Criteria, ug/L Carcinogen? Water Quality Criteria Coeff of Variation (Cv) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Metal Criteria Translator, decimal Maximum Daily Effluent Limit, ug/L Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 SILVER - 7740224 11M dependent on hardness. THALLIUM 7440280 12MZINC- 7440666 13M hardness dependentCYANIDE 57125 14MNITRATE/NITRITE (N)METHYLENE CHLORIDE 75092 22VPHENOL 108952 10ABIS(2-ETHYLHEXYL) PHTHALATE 117817 13BBENZIDINE 92875 4BALDRIN 309002 1PHEPTACHLOR 76448 16P38 4 40 6 35 6 6 5 1 1 1 0.7 0.6 0.4 0.6 0.2 0.6 0.6 0.6 0.6 0.6 0.6 0.03 0.064 79.4 12 4.1 0.995 10 0.024 0.0028 0.0037 59.7 23000 0.0125 3.2 0 0 0 0 3.2 0 225 0 0 0 0 0 0 Acute 2.1779 - 91.2415 22 - - - - - 2.5 0.52 Chronic - - 52.2779 5.2 - - - - - 0.0019 0.0038 - 1.7 1000 9 10000 10 9000 0.045 2E-05 4E-08 3E-07 Acute 0.85 - 0.996 - - - - - - - - Chronic - - 0.996 - - - - - - - - N N N N N Y N Y Y Y Y Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.631 0.555 0.385 0.555 0.198 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.924 0.473 0.928 0.607 0.918 0.607 0.607 0.549 0.050 0.050 0.050 1.00 2.59 1.00 2.14 1.00 2.14 2.14 2.32 6.20 6.20 6.20 Acute 0.023 0.138 66.435 21.417 0.000 7.317 1.776 19.369 0.124 0.014 0.019 Chronic 0.017 0.039 21.267 6.119 0.000 2.091 0.507 5.534 0.035 0.004 0.005 NO n/a NO YES n/a n/a n/a n/a n/a YES YES Aquatic Life Limit Calculation 0.7 0.6 0.4 0.6 0.2 0.6 0.6 0.6 0.6 0.6 0.6 0.7 0.6 0.4 0.6 0.2 0.6 0.6 0.6 0.6 0.6 0.6 Acute 2.611 - 108.85 26.4 - - - - -3 0.624 Chronic -- - 209.327 21.84 - - - - -0.008 0.016 Acute 0.7337 - 47.8504 8.4766 - - - - -0.9632 0.2004 Chronic -- - 134.675 11.519 - - - - -0.0042 0.0084 0.7337 0 47.8504 8.4766 0 0 0 0 0 0.0042 0.0084 0.85 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 #DIV/0! #DIV/0! #DIV/0!#DIV/0!#DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0!#DIV/0! #DIV/0! 3.1 0.0 109.3 26.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Human Health Reasonable Potential s 0.6315 0.55451 0.38525 0.5545 0.19804 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.924 0.473 0.928 0.607 0.918 0.607 0.607 0.549 0.050 0.050 0.050 0.4044 1.03846 0.56982 0.8603 0.75913 0.86028 0.86028 0.9336 2.4895 2.4895 2.4895 11 11 11 11 11 37 11 37 37 37 37 0.0011 0.00604 8.33636 0.9385 2295.45 9.5E-02 7.8E-02 0.2523 0.0016 0.0002 0.0002 n/a NO NO NO NO NO NO YES YES YES YES Human Health Limit Calculation 33 0 18.7 10968 99 107750 370 99000 1.665 0.0007 2E-06 1E-05 #DIV/0!#DIV/0!#DIV/0!261.19 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Metal Criteria Translator, decimal LTA Coeff. Var. (CV), decimal Multiplier Max concentration (ug/L) at edge of… Maximum Daily Limit (MDL), ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Reasonable Potential Calculation - Page 2 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Carcinogen? s2=ln(CV2+1) Pn=(1-confidence level)1/n Long Term Averages, ug/L Effluent percentile value Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? Average Monthly Effluent Limit, ug/L # of Compliance Samples Expected per month Maximum Daily Effluent Limit, ug/L Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 HEXACHLOROBENZENE 118741 33BPENTACHLOROPHENOL 87865 9A (pH dependent in freshwater)BENZO(a)ANTHRACENE 56553 5B3,3 DICHLOROBENZIDINE 91941 23BCHRYSENE 218019 18BBENZO(b)FLUORANTHENE 205992 7BBENZO(a)PYRENE 50328 6BINDENO(1,2,3-cd)PYRENE 193395 37BDIBENZO(a,h)ANTHRACENE 53703 19BACRYLONITRILE 107131 2VNITROSODIMETHYLAMINE N 62759 41B1 1 1 1 1 1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.0115 0.022 0.0075 0.0135 0.011 0.009 0.0105 0.01 0.0085 0.25 0.0044 0.022 0 0 0 0 0 0 0 0 0 0 0 0 Acute - 24.0431 - - - - - - - - - Chronic - 15.178 - - - - - - - - - 5E-06 0.002 0.00016 0.0031 0.016 0.00016 1.6E-05 0.0002 2E-05 0.019 0.0007 Acute - - - - - - - - - - - Chronic - - - - - - - - - - - Y Y Y Y Y Y Y Y Y Y Y Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 Acute 0.059 0.114 0.039 0.070 0.057 0.046 0.054 0.052 0.044 1.291 0.023 Chronic 0.017 0.032 0.011 0.020 0.016 0.013 0.015 0.015 0.013 0.369 0.006 n/a NO n/a n/a n/a n/a n/a n/a n/a n/a n/a Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute - 28.8518 - - - - - - - - - Chronic - 63.7478 - - - - - - - - - Acute - 9.26382 - - - - - - - - - Chronic - 33.6227 - - - - - - - - - 0 9.26382 0 0 0 0 0 0 0 0 0 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! 0.0 28.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Human Health Reasonable Potential s 0.5545 0.55451 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 2.4895 2.48953 2.48953 2.4895 2.48953 2.48953 2.48953 2.4895 2.4895 2.4895 2.4895 37 37 37 37 37 37 37 37 37 37 37 0.0008 0.00059 0.0005 0.0009 0.00074 6.1E-04 7.1E-04 0.0007 0.0006 0.0168 0.0003 YES NO YES NO NO YES YES YES YES NO NO Human Health Limit Calculation 0.0002 0.074 0.00592 0.1147 0.592 0.00592 0.00059 0.0059 0.0006 0.703 0.0241 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent percentile value Reasonable Potential? Limit Required? Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Maximum Daily Limit (MDL), ug/L # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Multiplier Max concentration (ug/L) at edge of… Dilution Factor Reasonable Potential Calculation - Page 3 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) WQ Criteria for Protection of Human Health, ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Long Term Averages, ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Pollutant, CAS No. & NPDES Application Ref. No. Max Conc. at edge of Chronic Zone, ug/L # of Compliance Samples Expected per month Reasonable Potential? Limit Required? Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Multiplier Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 BIS(2-CHLOROETHYL)ETHER 111444 11BN- NITROSODI-N-PROPYLAMINE 621647 42BDDT 50293 7PDDT METABOLITE (DDE) 72559 8PDDT METABOLITE (DDD) 72548 9PCHLORDANE 57749 6PBHC - ALPHA 319846 2PBHC - BETA 319857 3PBHC - DELTA 319868 5PHEPTACHLOR EPOXIDE 1024573 17PTOXAPHENE 8001352 25P1 1 1 1 1 1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.0185 0.012 0.007 0.0036 0.00037 0.0025 0.0025 0.0041 0.0028 0.0036 0.175 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Acute - - 1.1 1.1 1.1 2.4 - - - 0.52 0.73 Chronic - - 0.001 0.001 0.001 0.043See Hexachlorocyclohexane-AlphaSee Hexachlorocyclohexane-Beta - 0.0038 0.0002 0.02 0.0044 1.2E-06 9E-07 7.9E-06 2.2E-05 4.8E-05 0.0013 - 2E-06 3E-05 Acute - - - - - - - - - - - Chronic - - - - - - - - - - - Y Y Y Y Y Y Y Y Y Y Y Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 Acute 0.096 0.062 0.036 0.018 0.002 0.013 0.013 0.021 0.014 0.018 0.904 Chronic 0.027 0.018 0.010 0.005 0.001 0.004 0.004 0.006 0.004 0.005 0.258 n/a n/a YES YES NO NO #VALUE! ######n/a YES YES Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute - -1.32 1.32 1.32 2.88 - - -0.624 0.876 Chronic - -0.0042 0.0042 0.0042 0.1806 #VALUE! ###### -0.016 0.0008 Acute - -0.42383 0.4238 0.42383 0.92472 - - -0.2004 0.2813 Chronic - -0.00222 0.0022 0.00222 0.09525 #VALUE! ###### -0.0084 0.0004 0 0 0.00222 0.0022 0.00222 0.09525 #VALUE! ###### 0 0.0084 0.0004 1.00 1.00 1.00 1.00 1.00 1.00 #VALUE! ###### 1.00 1.00 1.00 #DIV/0! #DIV/0!#DIV/0! #DIV/0!#DIV/0! #DIV/0! #VALUE! ###### #DIV/0!#DIV/0! #DIV/0! 0.0 0.0 0.0 0.0 0.0 0.3 #VALUE! ###### 0.0 0.0 0.0 Human Health Reasonable Potential s 0.5545 0.55451 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 2.4895 2.48953 2.48953 2.4895 2.48953 2.48953 2.48953 2.4895 2.4895 2.4895 2.4895 37 37 37 37 37 37 37 37 37 37 37 0.0012 0.00081 0.00047 0.0002 2.5E-05 1.7E-04 1.7E-04 0.0003 0.0002 0.0002 0.0118 NO NO YES YES YES YES YES NO n/a YES YES Human Health Limit Calculation 0.74 0.1628 4.4E-05 3E-05 0.00029 0.00081 0.00178 0.0481 0 9E-05 0.0012 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Reasonable Potential Calculation - Page 4 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent percentile value s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Long Term Averages, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 BENZO(k) FLUORANTHENE 207089 9BENDRIN 72208 14PENDRIN ALDEHYDE 7421934 15PDIELDRIN 60571 10P BENZO(k) FLUORANTHENE 207089 9BENDOSULFAN SULFATE 1031078 13PBHC - GAMMA 58899 4P (Lindane)2-CHLOROPHENOL 95578 1A1,3 DICHLOROBENZENE 541731 21B1,4 DICHLOROBENZENE 106467 22B1,2 DICHLOROBENZENE 95501 20B1 1 1 1 1 1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.01 0.0037 0.00415 0.003 0.01 0.00275 0.00325 0.014 0.0145 0.0145 0.0165 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Acute - 0.18 - 2.5 - - - - - - - Chronic - 0.0023 - 0.0019 - -See Hexachlorocyclohexane-Gamma (lindane)- - - - 0.0016 0.002 0.034 7E-08 0.0016 9 0.43 15 2 200 700 Acute - - - - - - - - - - - Chronic - - - - - - - - - - - Y N N Y Y N Y N N N N Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 6.20 Acute 0.052 0.019 0.021 0.015 0.052 0.014 0.017 0.072 0.075 0.075 0.085 Chronic 0.015 0.005 0.006 0.004 0.015 0.004 0.005 0.021 0.021 0.021 0.024 n/a YES n/a YES n/a n/a #VALUE!n/a n/a n/a n/a Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute -0.216 -3 - - - - - - - Chronic -0.00966 -0.008 - - #VALUE! - - - - Acute -0.06935 -0.9632 - - - - - - - Chronic -0.0051 -0.0042 - - #VALUE! - - - - 0 0.0051 0 0.0042 0 0 #VALUE! 0 0 0 0 1.00 1.00 1.00 1.00 1.00 1.00 #VALUE! 1.00 1.00 1.00 1.00 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! #DIV/0! #VALUE! #DIV/0! #DIV/0! #DIV/0! #DIV/0! 0.0 0.0 0.0 0.0 0.0 0.0 #VALUE! 0.0 0.0 0.0 0.0 Human Health Reasonable Potential s 0.5545 0.55451 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 0.050 2.4895 2.48953 2.48953 2.4895 2.48953 2.48953 2.48953 2.4895 2.4895 2.4895 2.4895 37 11 11 37 37 11 37 11 11 11 11 0.0007 0.00084 0.00094 0.0002 0.00067 6.2E-04 2.2E-04 0.0032 0.0033 0.0033 0.0037 NO NO NO YES NO NO NO NO NO NO NO Human Health Limit Calculation 33 0.0592 0.022 0.374 3E-06 0.0592 99 15.91 165 22 2200 7700 #DIV/0!#DIV/0!#DIV/0!7E-06 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Reasonable Potential Calculation - Page 5 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent percentile value s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal Waste Load Allocations, ug/L Long Term Averages, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Dilution Factors:Acute Chronic Facility 1.2 4.2 Water Body Type 37.0 Rec. Water Hardness 11.0 CHLOROISOPROPYL ETHER (BIS-2) 108601HEXACHLOROETHANE 67721 36BTRICHLOROBENZENE 1,2,4 120821 46BHEXACHLOROBUTADIENE 87683 34BBUTYLBENZYL PHTHALATE 85687 15B3,3 DICHLOROBENZIDINE 91941 23B1 1 1 1 1 1 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.0175 0.0105 0.018 0.0055 0.0225 0.0135 0 0 0 0 0 0 0 0 0 0 0 Acute - - - - - -#N/A #N/A #N/A #N/A #N/A ChronicSee Bis(2 Chloro-1-Methylethyl) Ether - - - - -#N/A #N/A #N/A #N/A #N/A 400 0.02 0.036 0.01 0.013 0.0031 #N/A #N/A #N/A #N/A #N/A Acute - - - - - -#N/A #N/A #N/A #N/A #N/A Chronic - - - - - -#N/A #N/A #N/A #N/A #N/A N Y - Y N Y #N/A #N/A #N/A #N/A #N/A Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.050 0.050 0.050 0.050 0.050 0.050 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! 6.20 6.20 6.20 6.20 6.20 6.20 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! Acute 0.090 0.054 0.093 0.028 0.116 0.070 #N/A #N/A #N/A #N/A #N/A Chronic 0.026 0.015 0.027 0.008 0.033 0.020 #N/A #N/A #N/A #N/A #N/A ######n/a n/a n/a n/a n/a #N/A #N/A #N/A #N/A #N/A Aquatic Life Limit Calculation 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute - - - - - - #N/A #N/A #N/A #N/A #N/A Chronic ###### - - - - - #N/A #N/A #N/A #N/A #N/A Acute - - - - - - #N/A #N/A #N/A #N/A #N/A Chronic ###### - - - - - #N/A #N/A #N/A #N/A #N/A ###### 0 0 0 0 0 #N/A #N/A #N/A #N/A #N/A ###### 1.00 1.00 1.00 1.00 1.00 #N/A #N/A #N/A #N/A #N/A ###### #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #N/A #N/A #N/A #N/A #N/A ###### 0.0 0.0 0.0 0.0 0.0 #N/A #N/A #N/A #N/A #N/A Human Health Reasonable Potential s 0.5545 0.55451 0.55451 0.5545 0.55451 0.55451 0.55451 0.5545 0.5545 0.5545 0.5545 Pn 0.050 0.050 0.050 0.050 0.050 0.050 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 2.4895 2.48953 2.48953 2.4895 2.48953 2.48953 #DIV/0!#DIV/0!#DIV/0!#DIV/0!#DIV/0! 11 37 37 37 11 37 #N/A #N/A #N/A #N/A #N/A 0.004 0.00071 0.00121 0.0004 0.00509 9.1E-04 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! NO NO NO NO NO NO #N/A #N/A #N/A #N/A #N/A Human Health Limit Calculation 33 4400 0.74 1.332 0.37 0.143 0.1147 #N/A #N/A #N/A #N/A #N/A #DIV/0!#DIV/0!#DIV/0!0.9762 #DIV/0!#DIV/0!#N/A #N/A #N/A #N/A #N/A Comments/Notes: References:WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Reasonable Potential Calculation - Page 6 Centralia WWTP Aquatic Life Freshwater Human Health Carcinogenic Acute=76.5, Chronic=44.2 mg/L Human Health Non-Carcinogenic Pollutant, CAS No. & NPDES Application Ref. No. Effluent Data # of Samples (n) Coeff of Variation (Cv) Effluent Concentration, ug/L (Max. or 95th Percentile) Calculated 50th percentile Effluent Conc. (when n>10) Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Water Quality Criteria Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Carcinogen? Effluent percentile value s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Max concentration (ug/L) at edge of… Reasonable Potential? Limit Required? # of Compliance Samples Expected per month LTA Coeff. Var. (CV), decimal Permit Limit Coeff. Var. (CV), decimal Dilution Factor Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required? # of Compliance Samples Expected per month Average Monthly Effluent Limit, ug/L Maximum Daily Effluent Limit, ug/L Waste Load Allocations, ug/L Long Term Averages, ug/L Limiting LTA, ug/L Metal Translator or 1? Average Monthly Limit (AML), ug/L Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1) Pn=(1-confidence level)1/n Multiplier Spawning/Rearing/ Supplemental Migration Criteria INPUT May 16 - Sept 30 Oct 1 - May 15 1. Chronic Dilution Factor at Mixing Zone Boundary 4.2 4.2 2. 7DADMax Ambient Temperature (T) (Upstream Background 90th percentile) 24.0 °C 16.7 °C 3. 7DADMax Effluent Temperature (95th percentile)23.7 °C 21.8 °C 4. Aquatic Life Temperature WQ Criterion in Fresh Water 17.5 °C 13.0 °C OUTPUT 5. Temperature at Chronic Mixing Zone Boundary:23.9 °C 17.9 °C 6. Incremental Temperature Increase or decrease:-0.1 °C 1.2 °C 7. Maximum Allowable Incremental Temperature Increase:0.3 °C 0.3 °C 8. Maximum Allowable Temperature at Mixing Zone Boundary:24.3 °C 17.0 °C A. If ambient temp is warmer than WQ criterion 9. Does temp fall within this warmer temp range?YES YES 10. Temperature Limit if Required:NO LIMIT 0.3 B. If ambient temp is cooler than WQ criterion but within 28/(Tamb+7) and within 0.3 °C of the criterion 11. Does temp fall within this incremental temp. range? --- --- 12. Temp increase allowed at mixing zone boundary, if required:--- --- C. If ambient temp is cooler than (WQ criterion-0.3) but within 28/(Tamb+7) of the criterion 13. Does temp fall within this Incremental temp. range?--- --- 14. Temp increase allowed at mixing zone boundary, if required:--- --- D. If ambient temp is cooler than (WQ criterion - 28/(Tamb+7)) 15. Does temp fall within this Incremental temp. range?--- --- 16. Temp increase allowed at mixing zone boundary, if required:--- --- RESULTS 17. Do any of the above cells show a temp increase?NO YES 18. Temperature Limit if Required?NO LIMIT 14.0 °C Freshwater Temperature Reasonable Potential and Limit Calculation Based on WAC 173-201A-200(1)(c)(i)--(ii) and the Water Quality Program Guidance. All data inputs must meet WQ guidelines. The Water Quality temperature guidance document may be found at: https://fortress.wa.gov/ecy/publications/summarypages/0610100.html Appendix K Plant Capacity Analysis BI1212191438SEA K-1 Appendix K Plant Process Calculations The following plant process Excel calculations for Phase II WWTP Improvements are included on the enclosed CD. • Phase II expansion under WWMM conditions • Phase II expansion under DWMM conditions • Phase II expansion under WWMM conditions and minimum 7-day temperature • Phase II expansion under WWMM conditions and minimum 30-day temperature • Phase II expansion under WWMM conditions and minimum day temperature • Phase II expansion with nutrient removal Appendix L City of Centralia Sewer Service Ordinance and Grinder Pump Agreement Chapter 15.10 SEWER SERVICE Sections: 15.10.010 Acronyms. 15.10.020 Definitions. 15.10.030 User charges. 15.10.040 Domestic user—Definition—Categories. 15.10.050 Domestic users—User charges. 15.10.060 Domestic-strength commercial/ industrial users—Definitions—Application of charge formula. 15.10.070 High-strength commercial/industrial users—User charges. 15.10.080 Collection of user charge—Delinquency—Penalties—Shut-off. 15.10.090 Implementation of user charge system. 15.10.100 Use of public sewers required. 15.10.110 Side sewers and connections. 15.10.120 Damage to sanitary sewer system. 15.10.130 Permit requirements. 15.10.140 Permit application and fees. 15.10.145 Term of permit. 15.10.150 Pipe material. 15.10.160 Joints. 15.10.170 Fittings and cleanout. 15.10.180 Connections to public sewer. 15.10.190 Size and slope of side sewer pipe. 15.10.200 Excavation and laying of pipe. 15.10.210 Testing and inspection. 15.10.220 Backfilling. 15.10.230 Side sewer contractor. 15.10.240 Latecomer reimbursement. 15.10.250 Septage dumping. 15.10.260 Prohibited discharge standards. 15.10.270 Commercial/industrial waste discharges. 15.10.280 Pretreatment of fats, oils and grease required. 15.10.290 Washing facilities, grease rack—Pretreatment. 15.10.300 Inspection fees. 15.10.310 Right of revision. 15.10.320 Entry of private property. 15.10.330 Violations. 15.10.340 Penalties. Page 1 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 15.10.350 Schedule of charges. 15.10.360 Effective date of charges. 15.10.010 Acronyms. “AKART” means all known, available, and reasonable methods (prevention, control, and treatment) to prevent and control pollution of the waters of the state of Washington. (Chapter 90.48 RCW.) AKART shall represent the most current methodology that can be reasonably required for preventing, controlling, or abating the pollutants associated with a discharge. AKART shall be applied by all users of the POTW. AKART includes best management practices and may be required by the utilities director for any discharge to the POTW. “ANSI” means the American National Standards Institute. “ASTM” means the American Society for Testing and Materials. “BOD” means biochemical oxygen demand as defined in CMC 15.10.020. “DOE” or “Ecology” means the Washington State Department of Ecology. “EPA” means U.S. Environmental Protection Agency. “ERU” means equivalent residential unit as defined under “normal domestic waste” in CMC 15.10.020. “FIFRA” means the Federal Insecticide Fungicide Rodenticide Act. “FOG” means fats, oils and grease. “NPDES” means the National Pollutant Discharge Elimination System. “POTW” means publicly owned treatment works as defined in CMC 15.10.020. “PVC” means polyvinyl chloride. “RCRA” means the Resource Conservation and Recovery Act. “RCW” means Revised Code of Washington. “SDR” means standard dimension ratios. “SIC” means Standard Industrial Classification. “SNC” means significant noncompliance as defined in CMC 15.10.020. “STEP” means septic tank effluent pumping. Page 2 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “TKN” means total kjeldahl nitrogen as defined in CMC 15.10.020. “TRC” means technical review criteria as defined in CMC 15.10.020. “TSCA” means the Toxic Substances Control Act. “TSS” means total suspended solids as defined in CMC 15.10.020. “SWDA” means the Solid Waste Disposal Act. “WAC” means the Washington Administrative Code. (Ord. 2148 § 2, 2005: Ord. 2051 § 1 (part), 2000). 15.10.020 Definitions. For the purpose of this chapter the words set out in this section shall have the following meanings: “Act” means the Federal Water Pollution Control Act, also known as the Clean Water Act (33 USC 1251 et seq.), as amended. “Administrative authority” means the public works director of the city of Centralia or his/her designee. “Alternative sewer systems” shall mean STEP systems, vacuum sewers, and grinder pump low-pressure sewer systems. “Applicable pretreatment standards” means for any specified pollutant: the more stringent of the city of Centralia prohibitive standards, state of Washington pretreatment standards, or applicable National Categorical Pretreatment Standards. “Authorized representative of the user”: 1. If the user is a corporation: the president, secretary, treasurer, or a vice president of the corporation in charge of a principal business function, or any other person who performs similar policy or decision-making functions for the corporation; or 2. If the user is a partnership or sole proprietorship: a general partner or proprietor, respectively; or 3. If the user is a federal, state, or local governmental facility: a director or highest official appointed or designated to oversee the operation and performance of the activities of the government facility, or his/her designee. 4. The individuals described in subsections (1) through (3) of this definition may designate another authorized representative if the authorization is in writing, the Page 3 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl authorization specifies the individual or position responsible for the overall operation of the facility from which the discharge originates or having overall responsibility for environmental matters for the company, and the written authorization is submitted to the city of Centralia. “Biochemical oxygen demand (BOD)” means the quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedures during five days at twenty degrees centigrade, usually expressed as a concentration (milligrams per liter (mg/l)). “Building drain” means that part of the lowest piping of a drainage system which receives the discharge from waste and other drainage pipes inside the walls of the building and conveys it to the side sewer beginning three feet outside the building wall. “Bypass” means the intentional diversion of waste streams from any portion of a user’s treatment facility. “Capital costs” means all costs incurred as a result of planning, permitting, design or construction of the wastewater collection or treatment facilities. “Categorical pretreatment standard or categorical standard” means any regulation containing pollutant discharge limits promulgated by EPA in accordance with Section 307(b) and (c) of the Act (33 USC 1317) which applies to a specific category of users and which appears in 40 CFR Chapter I, Subchapter N, Parts 405—471. “Categorical user” means a user covered by one or more categorical standards as defined herein. “Centralia urban region” means the city of Centralia and that portion of Lewis County outside the Centralia corporate city limits that will be served by the Centralia wastewater treatment facility, shown in Figure 2-3 of the 1999 Facility Plan as now in existence or hereinafter amended. “City” means the city of Centralia. “City council” means the governing body of the city of Centralia. “Combined business-residential user” means any user whose plumbing facilities serve both a domestic user and a commercial user. “Commercial user” means any nonresidential customer who engages in business activities or combination of business and residential activities if combined through a single-meter service. Page 4 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “Cooling water” means water used for cooling purposes generated from any use, such as air conditioning, heat exchangers, cooling or refrigeration. For purposes of this chapter, such waters are further divided into two subcategories: 1. Uncontaminated: water to which the only pollutant added is heat, which has no direct contact with any raw material, waste, intermediate, or final product, and which does not contain a level of contaminants detectably higher than that of the intake water. 2. Contaminated: water likely to contain levels of pollutants detectably higher than intake water. This includes water contaminated through any means, including chemicals added for water treatment, corrosion inhibition, or biocides, or by direct contact with any process materials, products, and/or wastewater. “Color” means the optical density at the visual wave length of maximum absorption, relative to distilled water. One hundred percent transmittance is equivalent to zero optical density. “Composite sample” means the sample resulting from the combination of individual wastewater samples taken at selected intervals based on an increment of either flow or time. “County” means Lewis County or any other county in which the city’s wastewater facilities are located. “Customer” (synonymous with user) means each person, business, property owner, sewer user, other entity separately billed by the city for the use or availability of public sewers in the Centralia sanitary sewer service area. “Department of Ecology (DOE)” means the Washington State Department of Ecology or authorized representatives thereof. “Domestic user” means any person who contributes, causes, or allows the discharge of wastewater into the city of Centralia’s POTW that is similar in volume and/or chemical make-up to domestic wastewater. For comparison, the utilities director may assume discharges of domestic wastewater from dwelling units to be one hundred gallons containing 0.2 pounds (three hundred mg/l) of BOD, 0.2 pounds (three hundred mg/l) of TSS and 0.024 pounds (24 mg/l) of TKN per capita per day, or as identified in the design of the POTW. “Domestic wastewater” means wastewater from residential kitchens, bathrooms, and laundries, and water borne human wastes from sanitary facilities in all other buildings, together with such groundwater infiltration or surface waters as may be present. Page 5 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “Environmental Protection Agency (EPA)” means the U.S. Environmental Protection Agency or, where appropriate, the regional water management division director, or other duly authorized official of the agency. “Enzyme” means any complex chemical produced by living cells that is a biochemical catalyst. “Explosion meter” means an electrical device that measures air quality for flammable or explosive gases. “Facility plan” means a report titled “City of Centralia Wastewater Facilities Plan,” 1999, CH2M Hill as the same now exists or hereafter amended. “Grab sample or discrete sample” means a sample which is taken from a waste stream on a one-time basis without regard to the flow in the waste stream and without consideration of time. “Grinder pump systems” means low pressure sewer systems designed to grind or macerate the materials in the domestic sewage discharged from a residential or commercial/industrial customer and pump it to the existing gravity sanitary sewer system. The system includes all tanks, pumps, valves, control systems, and the low-pressure force main pipe conveying the sewage to the gravity sewer. “Health department” means the Lewis County environmental health department. “Income,” as used herein, means gross income as defined in Section 61(a) of the Internal Revenue Code of 1954, as now in effect or hereafter amended, plus any and all social security retirement and/or disability payments, Veterans Administration retirement and/or disability payments, Railroad Retirement Board pension and/or disability payments, and payments received from any other public or private pension, retirement, profit-sharing and disability plans, and unemployment compensation. “Indirect discharge or discharge” means the introduction of pollutants into the POTW from any nondomestic source regulated under Section 307(b), (c), or (d) of the Act. The discharge into the POTW is normally by means of pipes, conduits, pumping stations, force mains, constructed drainage ditches, surface water intercepting ditches, and all constructed devices and appliances appurtenant thereto. “Industrial user” means any nonresidential user whose wastewater results from any process or activity conducted by that user. Such wastewater includes contaminated wash water or leachate from solid waste facilities that may enter the wastewater utility collection system. Page 6 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “Industrial wastewater” means water or liquid-carried waste from any industry, manufacturing operation, trade, or business which includes any combination of process wastewater, cooling water, contaminated stormwater, contaminated leachates, or other waters such that the combined effluent differs in some way from purely domestic wastewater, or is subject to regulation under the Federal Categorical Pretreatment Standards, the State Waste Discharge Permit program, or this chapter. “Interference” means the effect of a discharge or discharges on the POTW from one or more users which results in either: (1) inhibition or disruption of the POTW, its treatment processes or operations, or its sludge processes, use or disposal; (2) violation of any permit regulating the city of Centralia wastewater discharge or sewage sludge; or (3) prevention of sewage sludge use or disposal in compliance with any applicable statutory or regulatory provision or permit issued thereunder. (Application sludge regulations shall include Section 405 of the Clean Water Act (33 USC 1345 et seq.); the Solid Waste Disposal Act (SWDA), including Title II commonly referred to as the Resource Conservation and Recovery Act (RCRA) (42 USC 6901 et seq.); state regulations contained in any state sludge management plan prepared pursuant to Subtitle D of the SWDA; the Clean Air Act (42 USC 7401 et seq.); the Toxic Substances Control Act (TSCA) (15 USC 2601 et seq.); the Marine Protection, Research, and Sanctuaries Act (33 USC et seq.); and 40 CFR Part 503). “Low-income senior citizen user” shall be defined as sixty-two years of age or older and whose total income, including that of his or her spouse or cotenant, does not exceed the amount specified in RCW 84.36.381(5)(b)(ii) as the same now exists or is hereafter amended. “Low-income totally disabled user” shall be defined as any person who has been classified as totally disabled by the Social Security Administration and whose total income does not exceed the amount provided for low-income senior citizen users. “Maximum daily concentration allowed” means the maximum concentration of a pollutant allowed to be discharged at any time, determined from the analysis of any discrete or composited sample collected, independent of the industrial flow rate and the duration of the sampling event. “Medical wastes” means isolation wastes, infectious agents, human blood and blood products or byproducts, pathological wastes, sharps, body parts, fomites, etiology agents, contaminated bedding, surgical wastes, potentially contaminated laboratory wastes, and dialysis wastes. “National Pollutant Discharge Elimination System (NPDES)” as defined under Section 402 of the Clean Water Act. Page 7 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “New source” means: 1. Any facility constructed after proposed categorical standards applicable to operations conducted at the facility where published, provided the facility is or may be a source of discharge to the POTW, and: a. The building, structure, facility, or installation is constructed at a site at which no other source is located; or b. The new construction totally replaces the process or production equipment that causes the discharge of pollutants at an existing source; or c. Construction of a new source as defined under this paragraph has commenced if the owner or operation has either: (i) begun, or caused to begin any placement, assembly, or installation of facilities or equipment; (ii) begun, or caused to begin significant site preparation work including removal of existing facilities necessary for the emplacement of new source facilities or equipment; or (iii) entered into a binding contractual obligation for the purchase of facilities or equipment for use in operation of a new source. “New user” means any noncategorical user that plans to discharge a new source of wastewater to the city of Centralia’s collection system after the effective date of the ordinance codified in this chapter. This discharge may be from either a new or an existing facility. Any person that buys an existing facility discharging nondomestic wastewater will be considered an “existing user” if no significant changes in facility operation are made and wastewater characteristics are not expected to change. “Normal domestic waste” means one hundred gpd/c containing less than three hundred mg/l BOD and TSS, twenty-four mg/l TKN, one hundred mg/l FOG. “Overhead” means all costs and expenses, including administrative overhead and equipment replacement, chargeable directly to the operation and maintenance of the wastewater treatment and collection facilities. “Pass through” means a condition occurring when discharges from users, (singly or in combination), exit the POTW in quantities or concentrations which either: (1) cause a violation of any requirement of the city of Centralia’s NPDES or state waste discharge permit; (2) cause an increase in the magnitude or duration of a violation; or (3) cause a violation of any water quality standard for waters in the state promulgated under state regulations including Chapter 173-201A WAC. “Permittee” means any person or user issued a wastewater discharge permit by EPA, DOE or the city. Page 8 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “Person” means any individual, partnership, firm, company, corporation, association, joint stock company, trust, estate, any federal, state, or local governmental agency or entity, or any other entity whatsoever; or their legal representatives, agents or assigns. “pH” means a measure of the acidity or alkalinity of a substance, expressed in standard units (technically defined as the logarithm of the reciprocal of the mass of hydrogen ions in gram moles per liter of solution). “Pollutant” means any substance, either liquid, gaseous, solid, or radioactive, discharged to the POTW which, if discharged directly, would alter the chemical, physical, thermal, biological, or radiological properties of waters of the state of Washington including pH, temperature, taste, color, turbidity, oxygen demand, toxicity or odor. This includes any discharge likely to create a nuisance or render such waters harmful, detrimental or injurious to any beneficial uses, terrestrial or aquatic life, or to public health, safety or welfare. “Pollution prevention” means source reduction; protection of natural resources by conservation; or increased efficiency in the use of raw materials, energy, water or other resources. “Population equivalent” means a measure of wastewater production equivalent to one person served by the wastewater treatment facilities: one hundred gallons per day, 0.2 lbs per day BOD and TSS, three hundred mg/l BOD and TSS, 0.024 lbs per day or twenty-four mg/l TKN. “Population equivalent user factor” means the number of population equivalents assigned to each user for the purposes of calculating sewer service charges. “Pretreatment” means the reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater prior to (or in lieu of) introducing such pollutants into the POTW. This reduction or alteration can be obtained by physical, chemical, or biological processes; by process changes; or by other means (except by diluting the concentration of the pollutants unless allowed by an applicable pretreatment standard). “Pretreatment requirements” means any substantive or procedural local, state, or federal requirement related to pretreatment developed under Chapter 90.48 RCW and/or Sections 307 and 402 of the Clean Water Act or this chapter. “Pretreatment standards” means any pollutant discharge limitations including categorical standards, state standards, and limits of CMC 15.10.280, 15.10.290 and 15.10.300 applicable to the discharge of nondomestic wastes to the POTW. The term shall also include the prohibited discharge standards of this chapter, WAC 173-216-060, and 40 CFR Part 403.5. Page 9 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “Prohibited discharge standards or prohibited discharges” means absolute prohibitions against the discharge of certain substances; these prohibitions appear in CMC 15.10.260. “Public sewer” means a common sewer directly controlled by public authority. “Publicly owned treatment works (POTW)” means a treatment works, as defined by Section 212 of the Act (33 USC 1292) which is owned by the city of Centralia. This definition includes any devices or systems used in the collection, storage, treatment, recycling, and reclamation of sewage or industrial wastewater and any conveyances which convey wastes to a wastewater treatment plant. The terms shall also mean the city of Centralia. “Septage” means the liquid and solid material pumped from a septic tank, cesspool, or similar domestic sewage treatment system. This includes liquids and solids from domestic holding tanks, chemical toilets, campers, and trailers, when these systems are cleaned or maintained. “Sewage or wastewater” means water-carried human wastes or a combination of water- carried wastes from residences, business buildings, institutions and industrial establishments, together with such ground, surface, storm, or other waters as may be present. “Sewer” means any pipe, conduit, ditch, or other device used to collect and transport sewage. “Sewer service charges” includes all charges billed to a particular user. “Side sewer” means that part of the horizontal piping of a drainage system which extends from the end of the building drain and which receives the discharge of the building drain and conveys it to a public sewer, private sewer or individual sewage disposal system. “Significant industrial user”: 1. A user subject to categorical pretreatment standards; or 2. A user that: a. Discharges an average of twenty-five thousand gallons per day or more of process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler blowdown wastewater); or b. Contributes a process waste stream which makes up five percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or Page 10 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl c. Is designated as such by the DOE with input from the city of Centralia on the basis that it, alone or in conjunction with other sources, has a reasonable potential for adversely affecting the POTW’s operation or for violating any pretreatment standard or requirement. 3. Upon a finding that a user meeting the criteria in subsection (2) of this definition has no reasonable potential for adversely affecting the POTW’s operation or for violating any applicable pretreatment standard or requirement, the DOE may at any time, on its own initiative or in response to a petition received from a user or the city of Centralia and in accordance with procedures in 40 CFR 403.8(f)(6) determine that such user should not be considered a significant industrial user. “Significant noncompliance (SNC)” shall refer to a violation or pattern of violation of one of the following natures: 1. Chronic violations of wastewater discharge limits, defined here as those in which sixty-six percent or more of all wastewater measurements taken during a six-month period exceed the daily maximum limit or average limit for the same pollutant parameter by any amount; 2. Technical review criteria (TRC) violations, defined herein as those in which thirty- three percent or more of all wastewater measurements taken for each pollutant parameter during a six-month period equal or exceed the product of the daily maximum limit or the average limit multiplied by the applicable TRC (1.4 for BOD, TSS, fats, oils and grease, and 1.2 for all other pollutants except pH); 3. Any other discharge violation that the city of Centralia believes has caused, alone or in combination with other discharges, interference or pass through (including endangering the health of the city of Centralia personnel or the general public); 4. Any discharge of pollutants that has caused imminent endangerment to human health, welfare or to the environment, or has resulted in the city of Centralia’s exercise of its emergency authority to halt or prevent such a discharge; 5. Failure to meet, within ninety days after the scheduled date, a compliance schedule milestone contained in a wastewater discharge permit or enforcement order for starting construction, completing construction, or attaining final compliance; 6. Failure to provide within thirty days after the due date, any required reports, including baseline monitoring reports, periodic self-monitoring reports, and reports on compliance with compliance schedules; 7. Failure to accurately report noncompliance; or Page 11 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 8. Any other violation(s) which the administrative authority determines will adversely affect the operation or implementation of the local pretreatment program. “Slug load” means any pollutant released in a discharge at a flow rate or concentration which could violate this chapter, or any discharge of a nonroutine, episodic nature such as an accidental spill or a noncustomary batch discharge. “Standard Industrial Classification (SIC) Code” means a classification pursuant to the “Standard Industrial Classification Manual” issued by the United States office of management and budget. “State” means the state of Washington. “STEP system” means septic tank effluent pumping sewer systems consisting of a liquid/solids separation tank with a pumping system discharging into the gravity sewer system. “Stormwater” means any flow occurring during or following any form of natural precipitation, and resulting from such precipitation, including snowmelt. “Total kjeldahl nitrogen (TKN)” means the total of organic compounds, i.e., amino acids, proteins, etc. (human waste). The TKN measures the combined amount of organic nitrogen and the amount of ammonia in a given sample. “Total suspended solids (TSS)” means the total suspended matter that floats on the surface of, or is suspended in, water, wastewater, or other liquids, and which is removable by laboratory filtering. “Toxic pollutant” means one or a combination of the pollutants listed as toxic in regulations promulgated by EPA under Section 307 (33 USC 1317) of the Act. “Treatment plant effluent” means the discharge from the city of Centralia POTW. “UGA” means the City’s urban growth area. “Upset” means an exceptional incident in which there is unintentional and temporary noncompliance with applicable treatment standards because of factors beyond the reasonable control of the user. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. “User or industrial user” means any nondomestic source of wastewater discharged to the POTW. This excludes domestic users as defined herein. Page 12 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl “Vacuum sewer systems” means sewage conveyance systems consisting of a receiving storage tank, valve system, collection pipeline and a vacuum pump conveying normal domestic sewage from residential or commercial/industrial customers to a discharge point into the sanitary gravity sewer system. “Wastewater.” See “Sewage.” “Wastewater discharge permit (industrial wastewater discharge permit, discharge permit)” means an authorization or equivalent control document issued by the DOE to users discharging wastewater to the POTW. The permit may contain appropriate pretreatment standards and requirements as set forth in this chapter. “Wastewater treatment facilities” means the city of Centralia wastewater treatment plant and outfall and all facilities designed for the collection and transmission of sewage to the plant. “Wastewater utility” means the entity reporting to the city manager, which is responsible for the operation, maintenance, upgrade and improvement of the wastewater collection and treatment system serving the city of Centralia urban area. (Ord. 2298 § 1, 2013: Ord. 2051 § 1 (part), 2000). 15.10.030 User charges. The user charge system shall distribute: A. The costs of operation and maintenance of the wastewater treatment facilities owned and/or operated by the city, including administrative costs; B. The costs of repayment of revenue bonds issued for financing the local capital cost of treatment plant renovations or expansion; and C. The costs of repayment of loans issued by state or federal agencies for utility work, to each user in proportion to such user’s contribution of wastewater to the wastewater treatment facilities. (Ord. 2051 § 1 (part), 2000). 15.10.040 Domestic user—Definition—Categories. A. A domestic user shall be defined as any user whose discharge into the sewage facilities originates only from a residence or residences in which no commercial or industrial activities are taking place. B. There shall be two categories of domestic users: 1. Single-family residential; and 2. Multiple-family residential. Page 13 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl The administrative authority will establish the population equivalent user factor for each category of domestic user based on water consumption data. (Ord. 2051 § 1 (part), 2000). 15.10.050 Domestic users—User charges. A. “Low-income senior citizen users” and “low-income totally disabled users” shall qualify to pay a reduced domestic user charge upon qualifying for the exemption by application made to the utilities customer service center; provided, however, this exemption shall only apply to the domestic user charge for low-income senior citizen users and totally disabled users residing in single-family dwelling units. This exemption shall not apply to residents and/or owners of multifamily structures. All low-income senior citizen customers and totally disabled customers applying for low- income senior citizen customer or totally disabled customer exemptions herein provided shall furnish to the utilities customer service center of the city of Centralia, Washington, a claim for exemption. Such form shall be furnished to the utilities customer service center on or before the thirty- first day of March of each year or within thirty days from the date of account opening or unexpected change in income status. B. The user charge for a single-family residential user, defined as a person whose structure, building, or property is designed to house a single family and is connected to a single side sewer to the public sewer, shall be as listed in CMC 15.10.350 (see CMC 15.10.110(B)). C. Where one side sewer serves more than one separate single-family residential building, structure, or property, the single-family residential user charge shall be charged continuously on each such connected building as long as water service is available for all such buildings, either from a municipal or private supply. D. The user charge for a multiple-family residential user, defined as a person whose structure, building, or property is designed to house more than one tenant or family in separate units and is connected by a single side sewer to the public sewer, shall be as listed in CMC 15.10.350. This category includes such establishments as apartments, multiplex units, trailer courts, or recreational vehicle courts. Each unit of the structure, building, or property, irrespective of occupancy or size, shall be included in the charge calculations as long as water service is available for that unit, either from a municipal or private supply. If the wastewater facility is required to own, operate or maintain a private collection system for such a user or for a combined commercial-residential user, or for a multiple commercial user, an appropriate contract addressing specific costs shall be entered into by the city and the user. Page 14 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl E. Where a single side sewer serves both commercial (or industrial) and domestic units (either single or multiple-family residential) served by the same water meter, the commercial/industrial rate provided in CMC 15.10.060 or 15.10.070 shall apply, without regard to the fact that the domestic units are connected with that side sewer. (Ord. 2298 § 2, 2013: Ord. 2051 § 1 (part), 2000). 15.10.060 Domestic-strength commercial/ industrial users—Definitions—Application of charge formula. A. A domestic-strength commercial/industrial user shall be defined as any user not falling into the classification of domestic user as defined. These users shall include, but are not limited to, such establishments as schools, churches, hotels, motels, offices, hospitals, businesses, combined business-residences, and industries with primarily domestic-type sanitary wastes. B. The same charge formula shall apply to all users within this classification. C. The user charge for all domestic-strength commercial/industrial users shall be as listed in CMC 15.10.350. This charge shall be based on monthly water meter readings. A minimum user charge equal to the single-family residential charge shall be levied if the charge calculated from water consumption would otherwise be less. D. No discount will be applied for water not returning to sanitary sewer facilities. A sprinkling meter may be utilized by commercial/industrial users for irrigation purposes only; no sewer billing will be levied on this commercial/industrial water use. (Ord. 2225 § 1, 2008: Ord. 2051 § 1 (part), 2000). 15.10.070 High-strength commercial/ industrial users—User charges. A. The high-strength user charge, as set forth in CMC 15.10.350, shall apply to those users discharging wastewater or wastes with BOD’s and/or suspended solids greater than three hundred mg/l, in quantities exceeding fifty pounds per day, and/or fats, oil and grease (FOG) greater than one hundred mg/l or greater than twenty-four mg/l TKN. B. The charge will be based on periodic monitoring of the wastewater entering the public sewer through the side sewer or by reported average values of typical wastewater strengths for that category of discharger. Users will administer these tests through a qualified person and use state certified testing labs at user’s expense. C. It shall be the responsibility of each sewer user whose wastewater strength exceeds that stipulated in subsection (A) of this section to notify the administrative authority that the discharge may be subject to high-strength surcharge. Those users who discharge higher strength wastes without approval from the administrative authority are subject to the penalties outlined in CMC 15.10.340. Page 15 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl D. If the city’s evaluation establishes that a particular user falls within the high-strength industrial/commercial user class, that user may file a written appeal with the administrative authority within thirty days after notification of the classification. Such appeal shall set forth in reasonable detail the source of error being appealed and the appellant’s grounds for modification thereof. If the city’s analysis determines there is no basis for modification, the decision of the administrative authority shall be final. E. All high-strength dischargers shall be subject to the terms of the industrial pretreatment program set out in CMC 15.10.270, 15.10.280 and 15.10.290. (Ord. 2051 § 1 (part), 2000). 15.10.080 Collection of user charge—Delinquency—Penalties—Shutoff. A. The following schedule for sewer user charge reductions shall be used for those domestic users who initiate or terminate sewer service between billing intervals. Charges computed for a actual water usage shall not be reduced. PERCENTAGE OF NORMAL CHARGE Service Interval After Last Bill or Before First Bill 0—7 Days 8—14 Days 15—22 Days 23—30 Days 31—45 Days 46—60 Days Monthly 25 50 75 100 — — B. Commercial/industrial users who initiate or terminate sewer service between billing periods shall be required to pay user charges only on the basis of water use. The minimum charge shall not apply to commercial/industrial customers in the case of a partial period of less than one month. C. Sewer users who desire to terminate service shall notify the finance department at city hall before the date of such termination. The notification shall include a forwarding address to which the final billing will be sent. (Ord. 2051 § 1 (part), 2000). 15.10.090 Implementation of user charge system. A. The city finance department shall keep and maintain the following records for purposes of evaluation and/or updating the user charge system: 1. Expenditures for operation and maintenance of the wastewater collection and treatment facilities; 2. Expenditures attributable to the administration of the wastewater treatment facilities; 3. Expenditures for the repayment of principal and interest on all outstanding revenue bonds and loans; Page 16 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 4. Moneys placed in the equipment rental replacement fund, interest accrued, and withdrawals from the fund; 5. Records of payments from individual users; 6. Records of water consumption from individual users; 7. A record of population equivalent user factor for the classifications of domestic users and each new commercial/industrial user; 8. A record of the total number of domestic and commercial/industrial users by category within the Centralia urban area; 9. Records of total user charge revenue and total revenues received from each user classification; B. The user charge program shall be reviewed annually to ensure continued equitability and generation of sufficient revenue to ensure self-sufficient operation and maintenance of the wastewater collection and treatment facilities. User charges shall be adjusted by action of the city council if such review reveals a deficiency in the rate structure. (Ord. 2051 § 1 (part), 2000). 15.10.100 Use of public sewers required. A. It is unlawful for any person to place, deposit, or permit to be deposited in any unsanitary manner upon public or private property within the corporate city limits of Centralia any human excrement, garbage, or other objectionable waste. B. The owners of all houses, buildings, or properties used for human occupancy, employment, recreation, or other purposes, situated within the city and abutting on any street, alley, easement, or right-of-way in which there is now located or may in the future be located a public sanitary sewer of the city, are required at their expense to install suitable sanitary plumbing fixtures therein and to connect such facilities correctly to the sanitary sewer in accordance with the provisions of this chapter within sixty days after the date of receipt of a notice in writing issued by the administrative authority for connection to be made, providing that the public sewer is within two hundred feet of the building, and the connection is approved by the administrative authority. Such notice will also be given when the owner is required to repair or completely replace the side sewer, such as during, but not limited to, a sewer rehabilitation project. When properties with existing dwellings are required to hook up to the sewer due to the extension of new sewer lines the administrative authority is authorized to negotiate a payment schedule for payment of capital facilities charges levied under CMC 15.10.350. Page 17 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl Special benefit fees and latecomer fees must be paid when the permit for the connection is issued. C. If any such connection, repair or replacement shall not have been made within the time provided, the administrative authority is authorized and directed, at its discretion, to either: 1. Cause such connection to be made, in which case the administrative authority shall file a statement of the cost thereof with the finance director and thereupon a warrant shall be issued under the direction of the city council by the city finance director and against the wastewater utility fund, created by city of Centralia Ordinance No. 1600 passed on December 30, 1986, for the payment of such costs. Such amount, together with applicable interest, in accordance with state law, shall be assessed against the property upon which the building or structure is situated and shall become a lien thereon. Such lien may be enforced by termination of some or all of the utility services provided to the property or in any other manner authorized by law. Such total amount, when collected, shall be paid into the wastewater utility fund; or 2. Cause water service to the property to be terminated, if service is provided by the Centralia water utility. Notice to the owner and occupant shall be by certified mail, return receipt requested, with a copy to the Lewis County environmental health department. Action will be taken thirty days after receipt of notice in the event of failure of other alternatives or high pollution potential. Final decision on the alternative action to be selected by the administrative authority shall be based upon such factors as location of the unconnected building or structure, effectiveness of existing private treatment facilities, if present, and groundwater contamination potential. (Ord. 2179 § 1, 2006: Ord. 2051 § 1 (part), 2000). 15.10.110 Side sewers and connections. A. All costs and expenses related to the installation and connection, operation and maintenance, and replacement of the side sewer, including backflow devices, where required, shall be borne by the owner. The owner shall indemnify the city from any loss or damage that may directly or indirectly be occasioned by the installation of the side sewer. B. A separate and independent side sewer shall be provided for every building. If one building stands at the rear of another on an interior lot under the same ownership and no private sewer is available or can be constructed to the rear building through an adjoining alley, courtyard, yard, or driveway, the side sewer from the front building may be extended to the rear building and the whole considered as one building sewer, with prior approval of the administrative authority. If the administrative authority finds that it may be necessary or beneficial to allow two adjacent buildings to connect to the public sewer through a common side sewer, such side sewer shall have a diameter of six inches or greater. When such Page 18 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl connection is made under one owner, then later sold to multiple owners, it shall be the responsibility of the property owner(s) to provide proof of the recorded easement to the wastewater utility. Penalty for noncompliance after certified mail notice to the owner giving sixty days to remedy the situation may include termination of city water service to any or all involved buildings. C. Old side sewers may be used in connection with new buildings only after they are found, on examination by the administrative authority, to meet all requirements of this chapter. D. Any building required to connect to a public sewer shall also disconnect from existing cesspool(s) or septic tank(s). Procedures for abandoning cesspools and septic tanks shall be in accordance with the regulations and standards enforced by the Lewis County environmental health department. Failure to properly abandon may result in the termination of water and sewer service, at the discretion of the administrative authority and on the advice of the Lewis County environmental health department. E. Any residential, commercial or industrial user requesting connection with the public sewer, shall first install or have installed an approved water meter, if such meter is not already installed. If the user obtains or can obtain water from sources other than the municipal supply, the meter shall measure the incoming flow from all such sources, and the installation and maintenance of the meter shall be at the user’s expense. In circumstances where the wastewater flow is not generated through a metered water supply, the wastewater discharge must be metered directly. The meter shall be installed and maintained at the property owner’s expense. Such a meter must be located to allow easy accessibility to city staff. Such direct readings will be increased by twenty percent for billing purposes to gain equivalency with other user’s billing basis of nonreturning flow. If either type of meter is found to be defective or otherwise inoperative, usage shall be estimated by the city to be at the highest monthly level recorded for the preceding twelve months. Such meter shall be repaired within sixty days of notification from the administrative authority. (Ord. 2051 § 1 (part), 2000). 15.10.120 Damage to sanitary sewer system. In the event of damage caused by a person, firm or corporation to the city’s sewer system, the city reserves the right to reject same and then charge such responsible party the cost of labor, materials, equipment and overhead, which billing, if unpaid sixty days thereafter, shall be turned over to a collection agency as designated by the city, thereto including, but not limited to, lien and discontinuance of service. (Ord. 2051 § 1 (part), 2000). 15.10.130 Permit requirements. Page 19 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl A. No person shall uncover, make any connections with or opening into, use, alter, or disturb any public sewer or appurtenance thereof, or engage in the construction of a side sewer, either on private property or within public rights-of-way, without first obtaining a written side sewer permit from the city community development department. In the event such sewer service is outside the city, the applicant by applying therefore and accepting such service shall be deemed bound by the current and future ordinances of the city affecting such sewer service. B. A side sewer permit will be required for each individual structure to be connected and for the collection system of a multiple dwelling or multiple commercial installation. C. Application for a side sewer permit will be made by a registered, bonded, insured side sewer contractor or the owner of the property to be served, in accordance with CMC 15.10.230. D. No side sewer contractor shall do any side sewer work under any other person’s permit nor shall any unauthorized person do any side sewer work under a side sewer contractor’s permit, except as may be otherwise authorized by the administrative authority. E. When a side sewer is to be installed across the private property of another person, the applicant for the side sewer must first provide proof that a duly executed easement has been obtained from other such property owner and officially recorded. A copy shall be provided by the applicant for the wastewater utility records. F. When work or excavation is performed within the public right-of-way, a right-of-way permit is required. This permit shall be obtained for the work prior to issuance of a side sewer permit by the city. G. The issuance of a side sewer permit by the city shall not relieve the permit holder from the responsibility of obtaining other such permits or licenses as may be required by the city, the county, or other jurisdictions in which the side sewer is installed. Permit holders shall contact other utilities for location of their facilities before starting excavation through the underground utilities locating service toll-free number (1-800-424-5555). H. Before a permit shall be issued for the construction of any side sewer to serve any commercial or industrial users, as defined in CMC 15.10.060(A) or 15.10.070(A), the applicant shall first supply proof that an approved water meter has been installed, or will be installed, during the process of constructing the side sewer, in accordance with CMC 15.10.110(E). Alternatively, a direct flow measuring device, in accordance with CMC 15.10.110(E) will be required. Page 20 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl I. The side sewer permit shall expire one hundred eighty days after the date of issuance. Upon expiration, the applicant must re-apply and pay for a new side sewer permit and all other applicable fees. (Ord. 2051 § 1 (part), 2000). 15.10.140 Permit application and fees. A. There shall be nine classes of side sewer permits/fees: (1) for single-family residential service; (2) for multiple-family residential service; (3) for service to establishments producing commercial or industrial wastes; (4) for alteration or abandonment of an existing side sewer; (5) for infiltration and inflow (I&I) rehabilitation permits; (6) for residential grinder pump connection; (7) for commercial and industrial grinder pump connection; (8) for after hours or holiday inspection fee; and (9) for re-inspection fee. The permit application shall be supplemented by approvable plans, specifications, or other information considered pertinent in the judgment of the administrative authority. B. Permit Fees (Includes Inspection During Normal Business Hours). 1. For each single-family residential connection to public sewer, fifty dollars. 2. For each multiple-family residential connection to public sewer, seventy-five dollars. 3. For each commercial or industrial connection to public sewer, one hundred dollars. 4. For alteration, abandonment or repair to existing connection, or complete replacement of side sewer, fifty dollars. 5. I&I rehabilitation project, no charge. 6. Grinder pump residential connection permit, one hundred dollars. 7. Grinder pumps commercial or industrial connection, one hundred fifty dollars. 8. After hours or holiday inspection fee, one hundred dollars. 9. Re-inspection fee, fifty dollars: one hundred dollars if after hours. C. Demolished or Removed Buildings. The property owner or their contractor engaged in demolishing or removing any structure connected to the public sewer shall notify the city of such work, obtain an abandonment permit from the community development department, and shall expose and plug the side sewer connection of such structure at the property line in accordance with the requirements found in the city of Centralia’s design and development Page 21 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl guidelines. A city inspector must observe and document all abandonments. Obtaining an abandonment permit does not relinquish the right to a future connection. D. Permit fees shall be paid to the community development department, with such amount credited to the wastewater utility, which conducts such inspections. E. Reference codes adopted by the city include the most current Washington State Uniform Plumbing Code and the most current DOE manual “Criteria for Sewage Works Design.” Specifications included in this chapter shall prevail when in conflict with, or where not addressed by, the aforementioned codes. In unclear circumstances, interpretation will be made by the administrative authority. (Ord. 2298 § 3, 2013: Ord. 2051 § 1 (part), 2000). 15.10.145 Term of permit. A. Work authorized by permit shall be completed within one hundred eighty days from date of approval by the city, unless extended by the building official. If a building permit is also required, fees shall be collected and both permits shall be obtained simultaneously. If work is not completed within one hundred eighty days or work is suspended or abandoned during the one hundred eighty day period, the permit shall expire and become null and void. Projects where the permit has been deemed null and void shall require the issuance of a new permit accompanied by the required fees and plan reviews. B. In the event that permit becomes null and void, the following shall not be refunded: 1. Sewer connection permit fees; 2. Latecomer fees; 3. Five percent capital facility fees. (Ord. 2051 § 1 (part), 2000). 15.10.150 Pipe material. A. Pipes acceptable for gravity side sewers shall be as follows: 1. Ductile iron: ANSI A 21.51, thickness class 51; 2. Polyvinyl chloride (PVC): ASTM D3034 with SDR equals 35. B. The water and wastewater utilities director, wastewater manager, lead collections technician and city engineer, as a committee of four shall consider any proposed sewer pipe other than those specifically set forth in subsection (A) of this section to determine its acceptability for use. C. Whenever possible, side sewers should be laid at least ten feet horizontally from any existing or proposed water main. Should local conditions prevent a lateral separation of ten Page 22 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl feet, a sewer may be laid closer than ten feet to a water main if the sewer is constructed of ductile iron or C-900 PVC pipe with watertight joints, and: 1. It is laid in a separate trench; 2. It is laid in the same trench with the water mains located at one side on a bench of undisturbed earth; 3. In either case the elevation of the crown of the sewer shall be at least eighteen inches below the invert of the water main. (Ord. 2051 § 1 (part), 2000). 15.10.160 Joints. A. All joints and connections shall be gastight and watertight, as determined by the testing and inspections procedures outlined in this chapter. B. Joints for PVC pipe shall be rubber-gasketed type conforming to ASTM D3212. C. Joint for ductile-iron pipe shall be push-on type or mechanical joint conforming to ANSI A21.11. D. Pipe and joints shall be installed in accordance with the instructions furnished by the pipe manufacturer and approved by the administrative authority. E. No glued joints will be accepted. F. Other joining materials and methods may be used only with the approval of the administrative authority. (Ord. 2051 § 1 (part), 2000). 15.10.170 Fittings and cleanout. A. The side sewer shall be laid at uniform grade and in straight horizontal alignment. Changes in horizontal alignment shall be made only with bends, wye branches, or a combination of a wye branch and bend. B. All change of horizontal alignment forty-five degrees or greater shall be made with a wye branch and bends as required, with the straight through opening capped for use as a cleanout. Where a ninety degree bend is required, two forty-five degree bends will be installed to complete the bend. No ninety degree fittings shall be allowed. C. A cleanout shall be installed thirty-six inches from all buildings unless permission to change the location of such cleanout has been obtained from the administrative authority. Additional cleanouts, including those used for commercial properties, shall be installed in locations designated by the administrative authority but in no case shall the distance between cleanouts exceed one hundred feet. Page 23 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl D. Suitable frames and covers of a type designated by the administrative authority shall be used for all cleanouts on commercial property and in paved areas, and such frames shall be cast in a concrete block thirty inches high by thirty inches wide by eight inches deep flush with the final paving. E. All cleanouts not in paved areas shall extend to within eighteen inches of the ground surface. All cleanouts shall be capped with appropriate plugs, using the standard compression joint of the pipe being used, to prevent entry of dirt, roots, or groundwater and shall be secured against back pressure. F. A test tee shall be provided at the private property and right-of-way boundary and at any other required point or points, as determined by the administrative authority, to ensure that all portions of the side sewer can be tested. G. It shall be the responsibility of the permit holder to install all risers, cleanouts, castings, concrete blocks, etc., required before the side sewer will be approved by the city. H. Backwater Valves. The Uniform Plumbing Code requires backwater valves on building sewers where a finished floor is below the rim of the upstream manhole. Backwater valves, if they are installed, must be located within the building footprint upstream of the cleanout. The city is not responsible for their installation, maintenance, or operation. (Ord. 2298 § 4, 2013: Ord. 2051 § 1 (part), 2000). 15.10.180 Connections to public sewer. A. The connection of the side sewer shall be made at a wye or tee. B. Connections at other than an existing wye or tee shall be made only by city personnel or a licensed side sewer contractor with the cost borne by the permit holder. Any work done by city personnel shall be billed for actual costs plus overhead. Terms in CMC 15.10.120 shall apply. C. If the joint type or dimensions of the wye or tee in the public sewer are different from that of the side sewer pipe, a transition adaptor approved by the administrative authority shall be used to connect the side sewer to the wye or tee. If a suitable transition is not obtainable, the method of making the connection shall be approved by the administrative authority. D. Connection to the building drain pipe shall be made by means of flexible clamp-type coupling or by other approved method. E. No connections from gutters, roof drains, down spouts, surface drains or yard drains shall be allowed to the sanitary sewer system. Page 24 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl F. The portion of the building (side) sewer located on the customer’s property is owned by the property owner and it shall be their responsibility to keep the sewer in good working order and free from ground water or surface runoff water. G. Repair to a side sewer shall be made within thirty days from receipt of notice to the owner of the property. In the event of an emergency, the city may establish a shorter period of time for the repair to be made or, if the owner cannot be located or does not promptly make such repairs, the city may make the repairs and bill the owners under the procedure of CMC 15.10.100(C)(1). H. Alternative Systems. In the event that gravity sewer service is not feasible, as determined by the administrative authority, alternative sewer systems may be permitted. Any alternative sewer system (grinder pumps, vacuum sewers) must be installed at the developer or property owner’s expense in accordance with the city’s design and development guidelines and the current DOE manual “Criteria for Sewage Works Design.” A service agreement provided by the city of Centralia will be signed and notarized stating that all maintenance and inspections shall be the responsibility of the system owner. System owners shall provide a property easement for city staff to access the installation for inspection purposes. Upon completion of installation, successful startup, and acceptance by the city, it shall be the owner’s responsibility to contract with a qualified contractor to work on such systems and to contact the city if work is performed on the grinder pump system. All alternative systems will be equipped with pigging ports for cleaning of the force mains, where appropriate and as determined by the administrative authority. 1. The following maintenance is required: a. Commercial grinder facilities must have their grinder systems integrity verified by a qualified technician on an annual basis. The frequency of the annual inspection may be increased if the system has a history of nonperformance and unreliability. b. Residential systems must have their grinder systems integrity verified by a qualified technician every three years. The frequency of the three-year inspection may be increased if the system has a history of nonperformance and unreliability. c. All inspection/maintenance records and repairs shall be e-mailed or mailed to the city of Centralia wastewater department for record keeping purposes. d. The owner shall provide the city of Centralia a copy of the manufacturer’s operation and maintenance manual to be kept on record for the life of the system as required by the Washington State Department of Ecology. e. All alterations to the system will be strictly monitored by the city of Centralia. Page 25 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl I. Sewer connections will not be allowed outside of the city’s UGA boundary unless the applicant provides a certificate from Lewis County allowing the connection because of an immediate health or safety problem that cannot otherwise be resolved. (Ord. 2298 § 5, 2013: Ord. 2051 § 1 (part), 2000). 15.10.190 Size and slope of side sewer pipe. A. The side sewer pipe shall be six inches in diameter from the public sewer main to the property line. From the property line to the building, the side sewer shall be no less than four inches in diameter. If more than one occupied building is attached to the same building sewer as allowed in CMC 15.10.110(B), the diameter of the side sewer shall not be less than six inches from the building to the points of junction of the sewer lines. Side sewers to multiple structures, commercial establishments, or industrial buildings shall not be less than six inches in diameter. B. All side sewers shall be laid on a uniform slope of not less than one-fourth inch per foot, wherever possible. Where it is impossible to obtain a one-fourth inch per foot slope due to the depth of the public sewer or to the structural features arrangements of the building, a slope of not less than one-eighth inch per foot is permissible, when approved by the administrative authority. Reduced slopes will require an increase in pipe size. C. In any building, structure, or premises in which the elevation of plumbing fixtures is too low to permit gravity flow to the public sewer, service may be provided by approved ejectors, pumps, or other equally efficient, approved mechanical devices approved by the administrative authority. When only the lower floor of a structure is too low for gravity flow, the remaining floors must flow by gravity. D. The discharge line from the ejectors, pumps, or other mechanical devices shall be provided with an accessible backflow valve and gate valve. The discharge line shall connect to the gravity side sewer at the crown of the side sewer through a wye fitting. All such installations shall conform with the current requirements set forth by DOE in “Criteria for Sewage Works Design,” Section C1-10. E. When the administrative authority determines there is a possibility of backup in the side sewer from head pressure in the public sewer, flow from any building drain lower than the gravity sewer shall be raised by approved means, or, if determined necessary by the administrative authority for protection against flooding or surcharge, a backflow valve shall be installed and maintained at the owner’s expense. F. Effective operation of any backflow valve shall be the responsibility of the owner of the building sewer. The city shall be saved harmless from any damage or injury sustained from installation or operation of said backflow valve. Page 26 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl G. All pump installations must meet all pertinent building and plumbing codes, current city development standards, and the most current DOE manual “Criteria for Sewage Works Design,” and must be approved by the administrative authority before installation. (Ord. 2051 § 1 (part), 2000). 15.10.200 Excavation and laying of pipe. A. All excavation required for the installation of a side sewer shall be open trench work unless otherwise approved by the administrative authority. B. The side sewer permit holder, before beginning excavation in the public right-of-way area, shall have at the site sufficient barricades to properly protect the work. The barricades shall meet the requirements as listed in the current “Manual of Uniform Traffic Control Devices.” C. The side sewer permit holder shall comply with any additional city, county, state, or other jurisdictional laws, ordinances, and regulations relating to the safety and protection of the excavation, and proper work practices when asbestos-containing pipe is involved. D. When unsuitable bedding, such as rock, is found, as determined by the administrative authority, the side sewer trench shall be over-excavated and a bedding of sand or fine gravel a minimum of four inches deep shall be prepared. Gravel shall be three-quarter inch maximum in size. If the trench is unintentionally over-excavated, the bottom shall be brought to proper grade using this same bedding material. E. All pipe shall be laid true to grade with the bell upstream. Pipe shall be cradled in the prepared trench bottom. The bottom of the trench shall be smooth and free from large rocks that could damage the side sewer pipe. (Ord. 2051 § 1 (part), 2000). 15.10.210 Testing and inspection. A. It shall be the duty of the person installing the side sewer as authorized by the permit to notify the utilities department orally or in writing that the sewer is ready for inspection. Twenty-four hours may be required after the notification before the actual inspection. Inspections can be made on Saturdays, Sundays or holidays, provided the inspection is scheduled forty-eight hours in advance and the contractor or owner agrees to pay an additional one hundred dollar inspection fee prior to inspection (CMC 15.10.140(B)). B. Side sewers shall be tested for their entire length from the public sewer by testing for visible leakage before backfilling by inserting a removable plumber’s plug at the connection of the side sewer to the public sewer and filling to a line with water to a level of at least one foot above the top of the side sewer at its connection with the building drain. A test tee or tees as required in CMC 15.10.170(F) shall be used for insertion of the plug and shall be secured against backpressure upon completion of the test. A special fitting, provided by the Page 27 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl permit holder, shall be inserted into the cleanout fitting at the connection to the building drain to provide a short standpipe to obtain a one-foot head pressure at that point. The side sewer permit holder or a licensed side sewer contractor must be present at the job during the full duration of the inspection. C. Products used to seal the inside of the pipe (such as grout, etc.) are not to be used to obtain a passing test. D. It shall be the duty of the holder of a permit to make sure that the work will pass inspection by performing the test described in subsection (B) of this section before giving notification for inspection. If an additional inspection is necessary due to test failure and/or improper installation, a charge of fifty dollars shall be made for each additional inspection. E. Notices of corrections or violations shall be written by the administrative authority and may be posted at the site of the work or mailed or delivered to the permittee or his authorized representative. Refusal, failure, or neglect to comply with any such notice or order within ten days after receipt thereof shall be considered a violation of this code and shall be subject to the penalties for violations set forth elsewhere in this code. F. Upon satisfactory completion of the leakage test and inspection, a certificate of approval shall be issued by the administrative authority on demand. (Ord. 2298 § 6, 2013: Ord. 2051 § 1 (part), 2000). 15.10.220 Backfilling. A. Trenches shall be backfilled within forty-eight hours after successful completion of inspection. Backfilling of trenches and restoration of roadway surfacing of any thoroughfare or right-of-way, public or private, shall be the responsibility of the permit holder. B. No backfill shall be placed over pipe until the work has been inspected and approved by the administrative authority. Any portion of the side sewer covered before inspection shall be uncovered at the owner’s expense within two days after notice to do so has been issued by the administrative authority. Re-inspection of the site will cause the owner/contractor to be subject to a fifty-dollar re-inspection fee. C. Trenches shall be carefully backfilled by tamping to a depth of six inches above the pipe to avoid damaging the pipe. All backfill between the public sewer and the property line shall be water-settled or mechanically tamped in six-inch layers to minimize settlement. Any settlement that occurs within twenty-four months after backfilling shall be corrected at the expense of the permit holder. Additional fill and surfacing materials as approved by the city engineer shall be placed to restore the settled area to original grade. Page 28 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl D. A minimum of six inches of gravel surfacing shall be temporarily placed in the public right-of-way or be temporarily placed in the public right-of-way or traveled areas in commercial properties. Final surfacing equivalent to the adjoining undisturbed roadway shall not be placed until such time as, in the opinion of the city engineer, final settlement has taken place. E. All pipe installations shall be bedded and backfilled to conform to the pipe manufacturer’s specifications. F. Minimum cover for side sewers shall be eighteen inches, except as hereafter provided: 1. Minimum cover for side sewers at the property line shall be four feet below the crest of the public right-of-way at the property line. 2. Minimum cover for side sewers crossing a ditch in the public right-of-way shall be four feet six inches. G. Where it is necessary for water and sewer lines to cross each other, the crossing shall be at an angle of approximately ninety degrees and the sewer shall be located eighteen inches or more below the waterline. The administrative authority may require that the sewer be constructed of ductile iron for a distance of at least ten feet on each side of the water main, and/or be placed inside of a protective casing. H. Failure to call for an inspection will be cause for termination of water service thirty days after receipt of notification. The administrative authority will send such notification by certified mail, return receipt requested. A copy shall be mailed to the Lewis County environmental health department. (Ord. 2051 § 1 (part), 2000). 15.10.230 Side sewer contractor. A. No person shall hereinafter engage in the business of installing building sewers or in connecting building sewers to any public sewer of the city of Centralia unless such person is registered, bonded and insured as required by the laws of the state of Washington; provided, however, and excepting from the above requirement, the bona fide property owner or direct family member, which would mean spouse, parents or children, may construct the building sewer provided they abide by all requirements of this chapter. For purposes of this chapter, the digging of the ditch in which to lay the sewer shall not of itself be construed as installation of a building sewer. B. If a side sewer contractor’s work is determined by the administrative authority to be unacceptable, further sewer permits may be denied for the following causes: failure to observe the rules and regulations issued by the administrative authority, or other codes referenced in this chapter, governing the construction and laying of side sewers; fraud or Page 29 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl misrepresentation in obtaining licensing, bonding and/or insurance; failure to pay for labor or material used in the construction of a side sewer; fraud or misrepresentation to the owner, agent, or occupant of a building for the purpose of obtaining a contract for the construction of a side sewer; or for nonpayment for work performed by the wastewater utility for the payment of which a side sewer contractor may be liable. (Ord. 2051 § 1 (part), 2000). 15.10.240 Latecomer reimbursement. A. The owner of the property must pay all applicable fees, including but not limited to any latecomer charges. All connections must be made in accordance with the requirements of this chapter; provided, however, that there shall be no new connections to an existing sewer system unless it is first determined by the administrative authority that such existing sewer system can adequately handle the additional sewage caused by such new connection or connections. B. A developer who enters into a latecomer reimbursement agreement with the city must initiate the process within ninety days of final acceptance of the sewer project. (Ord. 2179 § 2, 2006: Ord. 2051 § 1 (part), 2000). 15.10.250 Septage dumping. It is unlawful for any person, firm or corporation to deposit, dump, place, or leave septage, sewage, or effluent from any septic tank, cesspool, or other private or city of Centralia sewage disposal system within the corporate limits of the city of Centralia. (Ord. 2051 § 1 (part), 2000). 15.10.260 Prohibited discharge standards. A. General Prohibitions. No user shall introduce or cause to be introduced into the POTW any pollutant or wastewater which causes pass through or interference. These general prohibitions apply to all users of the POTW whether or not they are subject to categorical pretreatment standards or any other federal, state, or local pretreatment standards or requirements. (40 CFR 403.5(a) and WAC 173-216-060(2)(b)(i)). B. Specific Prohibitions. No user shall introduce or cause to be introduced into the POTW the following pollutants in any form (solid, liquid, or gaseous): 1. Any pollutant which either alone or by interaction may create a fire or explosive hazard in the POTW, including, but not limited to, waste streams with a closed-cup flashpoint of less than one hundred forty degrees Fahrenheit (sixty degrees Celsius) using the test methods specified in 40 CFR 261.21 (40 CFR 403.5(b)(1)), or are capable of creating a public nuisance (WAC 173-216-060(2)(b)(ii)). This includes waste streams sufficient to create a public nuisance or a hazard to life, or to prevent Page 30 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl entry into the sewers for maintenance or repair. At no time shall a waste stream cause two successive readings on an explosion meter to be more than five percent nor any single reading over ten percent of the lower explosive limit (LEL) of the meter at any point in the collection system or treatment works; 2. Any pollutant which will cause corrosive structural damage to the POTW, but in no case discharges with a pH less than 6.0 or more than 9.0, or having any other corrosive property capable of causing damage or hazard to structures, equipment, or personnel of the POTW, unless the system is specifically designed to accommodate such discharge and the discharge is authorized by an applicable wastewater discharge permit (40 CFR 403.5(b)(2) and WAC 173-216-060(2)(b)(iv)); 3. Any solid or viscous substances including fats, oils, and greases in amounts which may cause obstruction to the flow in a POTW or other interference with the operation of the POTW (40 CFR 403.5(b)(3) and WAC 173-216-060(2)(b)(vi)); 4. Any discharge of pollutants, including oxygen-demanding pollutants (BOD, etc.), released at a flow rate and/or pollutant concentration which, either singly or by interaction with other pollutants, sufficient to cause interference with the POTW (40 CFR 403.5(b)(4) and WAC 173-216-060(2)(b)(vi)); 5. Any waste stream having a temperature which will inhibit biological activity in the treatment plant resulting in interference, or cause worker health or safety problems in the collection system. In no case shall wastewater be discharged at a temperature which causes the temperature of the influent to the treatment plant to exceed one hundred four degrees Fahrenheit (forty degrees Celsius) unless the system is specifically designed to accommodate such a discharge, and the discharge is authorized by an applicable wastewater discharge permit (40 CFR 403.5(b)(5) and WAC 173-216-060(2)(b)(v)); 6. Any petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin, in amounts that will cause interference or pass through (40 CFR 403.5(b)(6)(ii)); 7. Any pollutants which result in the presence of toxic gases, vapors, or fumes within any portion of the POTW in a quantity that may cause acute worker health and safety problems (40 CFR 403.5(b)(7) and WAC 173-216-060(2)(b)(ii)); 8. Any trucked or hauled wastes, except at discharge points designated by the city and in compliance with all applicable city requirements and during specified hours (40 CFR 403.5(b)(8)); Page 31 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 9. Any noxious or malodorous liquids, gases, solids, or other wastewater which, either singly or by interaction with other wastes, are sufficient to create a public nuisance or a hazard to life, or to prevent entry into the sewers for maintenance or repair (WAC 173-216-060(2)(b)(ii)); 10. Any of the following discharges unless approved by the administrative authority under extraordinary circumstances such as the lack of direct discharge alternatives due to combined sewer service or need to augment sewage flows due to septic conditions (WAC 173-216-060(2)(b)(vii)): a. Noncontact cooling water in significant volumes, b. Stormwater, and other direct inflow sources, or c. Wastewaters significantly affecting system hydraulic loading, which do not require treatment or would not be afforded a significant degree of treatment by the POTW; 11. Any dangerous or hazardous wastes as defined in Chapter 173-303 WAC, as amended, except as allowed in compliance with that regulation (WAC 173-216-060(1) and 40 CFR Part 261); 12. Any substance which will cause the POTW to violate its NPDES, state waste discharge or other disposal system permits or causing, alone or in conjunction with other sources, the treatment plant’s effluent to fail a toxicity test; 13. Any substance which may cause the POTW’s effluent or treatment residues, sludges, or scums to be unsuitable for reclamation and reuse or would interfere with the reclamation process or cause the POTW to be in noncompliance with sludge use or disposal criteria, guidelines or regulations developed pursuant to the federal, state, or local statues or regulations applicable to the sludge management method being used; 14. Any discharge which imparts color which cannot be removed by the POTW’s treatment process such as dye wastes and vegetable tanning solutions, which consequently impart color to the treatment plant’s effluent, thereby violating the city’s NPDES permit. Color (in combination with turbidity) shall not cause the treatment plant effluent to reduce the depth of the compensation point for photosynthesis activity in the receiving waters by more than ten percent from the seasonably established norm for aquatic life; 15. Any discharge containing radioactive wastes or isotopes except as specifically approved by the administrative authority in compliance with applicable rate or federal Page 32 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl regulations including WAC 246-221-190 “Disposal By Release Into Sanitary Sewerage Systems”; and meeting the concentration limits of WAC 246-221-290, Appendix A, Table I, Column 2; and WAC 246-221-300, Appendix B; 16. Any sludges, screenings, or other residues from the pretreatment of industrial wastes or from industrial processes; 17. Any medical wastes, except as specifically authorized by the administrative authority; 18. Any detergents, surface-active agents, or other substances in amounts which may cause excessive foaming in the POTW; 19. Any incompatible substance such as: grease, animal guts or tissues, paunch contents, manure, bones, hair, hides or fleshings, entrails, whole blood, feathers, ashes, cinders, sand, spent lime, stone or marble dusts, metal, glass, straw, shavings, grass clippings, rags, spent grains, spent hops, wastepaper, wood, plastics, gas, tar asphalt residues, residues from refining or processing of fuel or lubricating oil, mud, or glass grinding or polishing wastes, or any other organic or inorganic matter greater than one-half inch in any dimension; 20. Persistent pesticides and/or pesticides regulated by the Federal Insecticide Fungicide Rodenticide Act (FIFRA); 21. Any wastewater, which in the opinion of the administrative authority can cause harm either to the sewers, sewage treatment process, or equipment; have an adverse effect on the receiving stream; or can otherwise endanger life, limb, public property, or constitute a nuisance, unless allowed under a legal and binding agreement by the administrative authority (except that no waiver may be given to any categorical pretreatment standard). C. Pollutants, substances, or wastewater prohibited by this section shall not be processed or stored in such a manner that they could be discharged to the POTW. D. Every building, structure, or premise used or occupied by any sewer user where any commercial or industrial operations are conducted or permitted which result in the discharge into the sewer system of any products, waste products, or other substances, matter, or liquid in the manner and to the extent prohibited in this section shall be equipped with an adequate and suitable grease trap, filter, or other interception device installed in such a manner that the product, waste products, or other substances, materials, or liquid herein set forth will not flow into or be discharged into the sanitary sewer system. The grease trap, filter, or other interceptor shall be adequately maintained, readily accessible for inspection Page 33 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl by the administrative authority at any time to ensure its proper operation, and is subject to the terms in CMC 15.10.280. E. The owner of any vehicle-washing facility shall install and maintain in a proper manner and at his own expense an approved sediment and oil trap located in the side sewer line. Records of proper cleaning and maintenance must be kept and made available to city inspectors. (Ord. 2051 § 1 (part), 2000). 15.10.270 Commercial/industrial waste discharges. A. The administrative authority may allow discharge of commercial/industrial waste not prohibited by CMC 15.10.260 into the public sewer. The decision on whether or not to allow any such discharge will be made on a case-by-case basis once the characteristics of the proposed waste discharge have been fully disclosed and will result in an individual agreement. B. In instances where the discharge of commercial/industrial waste into the public sewer is proposed, the administrative authority may: 1. Prohibit discharge into the public sewer; and/or 2. Require preliminary treatment (“pretreatment”) to acceptable condition for discharge into the public sewer; and/or 3. Require payment of an additional charge and fee as provided in CMC 15.10.350 for the added cost and expense of treating such waters or wastes so admitted into the sewage system; and/or 4. Require monitoring of the discharge as provided in CMC 15.10.070; and/or 5. Require user to obtain a state discharge permit. C. In cases where pretreatment is required, plans, specifications, and other information relating to the construction and installation of pretreatment facilities shall be submitted by the industry to the Ecology and the administrative authority for approval. No construction or installation thereof shall commence until written approval has been received from the administrative authority and Ecology. Such pretreatment facilities shall be constructed, operated, and maintained at the owner’s expense. The industry shall comply with the Ecology and the EPA pretreatment regulations and the state waste discharge permit program. D. Any person constructing a pretreatment facility, as required by the administrative authority or Ecology, shall also install and maintain at the facility owner’s sole expense a sampling and metering manhole for monitoring the discharge to the public sewer. Such Page 34 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl sampling and metering manhole shall be placed in a location approved by the administrative authority and in accordance with approved specifications. E. The city can require written permits and/or operating plans for any commercial or industrial discharger that does not fall under state and federal permit requirements. Noncompliance with the permit requirements are enforceable under the provisions of this chapter. (Ord. 2148 § 3, 2005: Ord. 2051 § 1 (part), 2000). 15.10.280 Pretreatment of fats, oils and grease required. A. Dischargers who operate newly constructed multiplex units or apartment complexes, restaurants, cafes, lunch counters, cafeterias, bars, or clubs; or hotels, hospitals, sanitariums, factories, churches or school kitchens; or other establishments that serve or prepare food where grease may be introduced to the sewer system shall have pretreatment facilities to prevent the discharge of fat waste, oil, or grease (FOG). Take-out food establishments or other establishments that prepare food, but do not cook in oil or grease, and who serve food only in disposable containers, may be exempted from this requirement, provided their discharges do not violate the general discharge prohibitions of this chapter. These pretreatment facilities must have grease interceptors installed in the waste line leading from sinks, drains, or other fixtures where grease may be discharged. The grease interceptors must meet, at a minimum, the specifications of the current Uniform Plumbing Code adopted by the city. The administrative authority is authorized to adopt and publish additional criteria for grease interceptors. Dischargers must maintain these facilities in a manner that will always prevent fat waste, oil, or grease from being carried into the sewer system. Fat waste, oil, or grease removed from such a facility shall not be disposed of in sanitary or storm sewers. B. All existing restaurants, cafes, lunch counters, cafeterias, bars, or clubs, or hotels, hospitals, sanitariums, factories, churches or school kitchens or other establishments that serve or prepare food where grease may be introduced to the sewer system which do not have a grease interceptor at the time of adoption of the ordinance codified in this chapter shall meet the requirements for grease, oil and fats by installing a grease interceptor within one year of the effective date of the ordinance codified in this chapter. Failure to install a grease interceptor within one year shall result in penalties as outlined in CMC 15.10.340. All grease removal systems must be approved by the administrative authority prior to installation. C. Use of Enzymes within the City of Centralia POTW. Introduction of any additives into a food service establishment’s wastewater system for the purpose of emulsifying FOG is prohibited, unless a specific written authorization from the FOG control program manager is obtained. (Ord. 2298 § 7, 2013: Ord. 2051 § 1 (part), 2000). Page 35 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 15.10.290 Washing facilities, grease rack—Pretreatment. Dischargers who operate automatic and coin-operated laundries, car washes, filling stations, commercial garages or similar businesses having any type of washing facilities or grease racks and any other dischargers producing grit, sand, oils, or other materials which have the potential of causing partial or complete obstruction of the building sewer or other areas in the sewer system shall install approved interceptors or tanks in accordance with the latest specifications adopted by the city such that excessive amounts of oil, sand and inert solids are effectively prevented from entering the city sewer. Effective April 1, 2000, all new car washes shall be closed loop, no discharge systems. Proof of required operation and maintenance records must be made available for city inspectors. (Ord. 2051 § 1 (part), 2000). 15.10.300 Inspection fees. All grease interceptors, oil/water separators, settling tanks and grit traps shall be installed, maintained and operated by the discharger at his own expense. The installation shall be kept in continuous operation at all times, and shall be maintained to provide efficient operation. Cleaning must be performed by a service contractor qualified to perform such cleaning. All material removed shall be disposed of in accordance with all state and federal regulations. Certification of maintenance shall be made readily available to city authorized personnel for review and inspection. Inspection and cleaning frequency of grease interceptors/traps is at the sole discretion of the administrative authority. If a failure to maintain settling tanks, grit traps, grease interceptors, or oil/water separators results in partial or complete blockage of the building sewer or other parts of the wastewater utility system, or adversely affects the treatment or transmission capabilities of the system, or requires excessive maintenance by the city, the discharger responsible for the facilities shall be subject to the remedies, including enforcement and penalties detailed in this chapter. Regular inspections will be conducted at no charge to the customer; however, re- inspections for systems not properly maintained will be charged a fifty-dollar re-inspection fee. (Ord. 2051 § 1 (part), 2000). 15.10.310 Right of revision. The city reserves the right to amend this chapter, and any permits issued under it, to provide for more stringent limitations or requirements on discharges to the wastewater utility system if such amendments are deemed necessary to comply with the prohibitions set forth in CMC 15.10.260, or are otherwise in the public interest. No vested right shall be created by the issuance of any permit under this chapter. (Ord. 2051 § 1 (part), 2000). 15.10.320 Entry of private property. The administrative authority, bearing proper credentials and identification, shall be permitted to enter upon all and any premises at all reasonable times for the purpose of inspection, Page 36 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl observation, measurement, sampling, testing of sewers and sewage, and performance of all other acts or duties required within the provisions of this chapter. (Ord. 2051 § 1 (part), 2000). 15.10.330 Violations. A. Definition. For the purposes of enforcement, the provisions of the rules establishing what constitutes a violation for general dischargers are set forth in this chapter. Those dischargers subject to national pretreatment standards will be subject to enforcement action in accordance with this chapter for any violations of the criteria and limitations specified in the categorical standard or the general pretreatment standards set forth in 40 CFR 403, same being incorporated herein by this reference. B. Sewer Connection Without Permission. It is unlawful to make or cause to be made or to maintain any sewer connection with any sewer of the city of Centralia, or with any sewer which is connected directly or indirectly with any sewer of the city of Centralia without having permission from the administrative authority. In the event permission has not been granted by the city of Centralia, the city shall seek remedies under CMC 15.10.340(D). C. Maximum Daily Concentration Allowed. The maximum daily allowable concentration for dischargers not regulated under national pretreatment standards is violated under the following circumstances: 1. The arithmetic mean of concentrations for eight consecutive samples collected within a twenty-four hour time period over intervals of fifteen minutes or greater is in excess of the limitation. 2. The concentration value obtained from composite sample that is representative of the twenty-four hour discharge is in excess of the limitation. 3. The concentration of any single sample (whether as single grab sample or a sample within a series) exclusive of any fats, oils, and grease exceeds the limitation by a factor of two and one-half times. 4. The arithmetic means of the concentration of fats, oils, or greases for three grab samples, taken no more frequently than at five minute intervals exceeds the limitation. D. pH Sample. The pH of any given sample is less than pH 6.0 or greater than pH 9.0. E. Temperature Limitation. The temperature limitation is exceeded for any single sample. F. Maximum Allowable Poundage Limitations. A violation shall occur if the maximum allowable effluent poundage limitation as established in the private wastewater discharge permit is exceeded. The daily poundage discharged shall be calculated using the volume of Page 37 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl effluent discharged that day times the concentration for that day either reported by the discharger or obtained through sampling by the city. The poundage shall be determined utilizing the formula: Lbs/day = conc. in mg/l x gal/day disch x 8.34/1,000,000 G. Reporting Requirements. A violation shall occur if any reporting requirements established by permit, accidental discharges, upset conditions, written request of the administrative authority, or as specified by general pretreatment standards (40 CFR 403.12) are not complied with. A violation shall occur when any person knowingly makes any false statement, representation, or certification in any application, record, report, plan or other documents filed or required to be maintained pursuant to this chapter, or who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required under this chapter. H. FOG Pretreatment Facility—Maintenance. A violation shall occur if there is any failure to maintain grease or grit interceptors or oil/water separators which causes maintenance on any sewer line to be greater than once every two years caused by excessive oil, grease, or fat build up in the sewer lines; or excess build up of sand, gravel or other materials clogging the sewer lines. The lack of any device to prevent discharge of grease, oil, fats, sand, gravel or any other materials which will cause excessive maintenance of the sewer lines shall not relieve the discharger of the responsibility of liability for any costs to the city for excessive maintenance and/or other costs, including overhead incurred by the city. I. Discharge of Dangerous Waste. A violation shall occur if any material listed on the discharge chemical products list of the state of Washington (WAC 173-303-9903) is discharged into any public sewer, or building sewer tributary thereto. J. Explosion Meter Readings. A violation shall occur if the readings on an explosion meter at any point in the collection system or wastewater treatment plant is greater than ten percent for a single reading or greater than five percent for two successive readings. K. Pass Through or Interference. Any discharge which causes pass through or interference with the wastewater treatment plant is a violation. L. Emergency Suspension of Service and Industrial Wastewater Discharge Permit or Limited Permit. 1. The city may, without advance notice, order the suspension of all or some portion of the wastewater treatment service and any applicable industrial wastewater discharge permit or limited permit to a discharger when it appears to the city that an actual or potential discharge: Page 38 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl a. Presents or threatens a substantial danger to the health or welfare of persons or to the environment; or b. Threatens to or interferes with the operation of the wastewater treatment plant or collection system; or c. Causes pass through to the environment or treatment process upset. 2. Any discharger notified of the city’s suspension order shall cease immediately all discharges. In the event of failure of the discharger to comply with the suspension order, the city may commence judicial proceedings immediately thereafter to compel the discharger’s specific compliance with such order and/or to recover civil penalties. The city shall reinstate the wastewater treatment service upon proof by the discharger of the elimination of the noncomplying discharge or of the conditions creating the threat as set forth in this section and payment of all penalties and fees. 3. In addition to all other rights and remedies, the city shall have the authority to immediately discontinue water service to a discharger if the city determines that such action is reasonably necessary to suspend service as authorized by subsection (L)(1) of this section. The city shall have the right of access onto the discharger’s private property to accomplish such termination of the water service. M. Termination of Treatment Services—Permit Revocation. Dischargers holding NPDES or state discharge permits will be referred to DOE for violations and enforcement/revocation of their permit. The city shall have the authority to terminate wastewater treatment services and to revoke any locally issued industrial wastewater discharge permit or limited permit of the discharger if it determines that the discharger has: 1. Failed to accurately report wastewater constituents and characteristics; or 2. Failed to report significant changes in wastewater constituents, characteristics, flow volumes or types of discharge to the wastewater treatment plant; or 3. Refused reasonable access to the discharger’s premises for purposes of inspection or monitoring; or 4. Violated conditions of the wastewater discharge permit; or 5. Violated any of the provisions of this chapter or regulations promulgated hereunder; or 6. Violated any lawful order of the city issued with respect to the discharger’s permit or this chapter; or Page 39 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 7. Tampers with, disrupts, damages or renders inaccurate any wastewater monitoring device required by this chapter. N. Other Violations. 1. If reports required by permit, this chapter or state or federal pretreatment regulations are submitted later than thirty days after they are due, the discharger shall be subject to civil penalties of five hundred dollars per day for a maximum of twenty working days. The penalty shall then be increased to one thousand dollars per day with a maximum fine of twenty thousand dollars. In the event the reports have not been submitted at the time the maximum penalty is imposed, the city shall seek remedies under CMC 15.10.340. 2. If any of the actions prescribed in any compliance schedule established by permit or by order of the administrative authority are not complete within thirty days of the time they are required to be complete, the discharger shall be subject to civil penalties of five hundred dollars per day for a maximum of sixty days for each day the action(s) have not been completed. In the event the actions have not been completed ninety days after the date scheduled in the permit or order the city shall seek remedies under CMC 15.10.340. 3. If a discharger fails to maintain grease, oil and/or sediment removal systems which result in excessive maintenance by the city of the collection system or treatment plant, the discharger shall be subject to a civil penalty of five hundred dollars which shall be added to the costs incurred by the city to perform the maintenance. If excessive maintenance is required a second time within a two year period, the penalty shall be one thousand dollars which shall be added to the costs of maintenance by the city. In the event excessive maintenance continues the city shall seek remedies under CMC 15.10.340. 4. Failure to provide accurate or complete information on any wastewater discharge reports or the requirements of a discharge permit shall result in a civil penalty of one hundred dollars for the first offense. Thereafter the discharger shall be subject to remedies under subsection (N)(1) of this section. 5. All commercial and industrial users are required to complete the annual user survey and submit the completed form to the utilities department within forty-five days of receipt. Failure to complete the survey within the required time will subject the user to penalties as outlined in this chapter. Page 40 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 6. In addition to the assessments described in this section any costs incurred by the city, including attorneys’ fees, due to violations subject to civil penalty shall be added to the total amount of the civil penalty assessment. (Ord. 2051 § 1 (part), 2000). 15.10.340 Penalties. A. Criminal Sanctions. Any person, firm, or corporation violating any of the provisions of this chapter shall, in addition to other penalties as are provided herein, be deemed guilty of a misdemeanor and upon conviction thereof shall be punishable by a fine not to exceed one thousand dollars plus costs and penalty assessments. Each separate day or any portion thereof during which any violation of this chapter occurs shall be deemed to constitute a separate offense, and upon conviction thereof shall be punishable as herein provided. B. Civil Liability for Expenses and Fines. Any discharger violating provisions of this chapter shall be liable for any expense, loss or damage caused to the collection system and/or treatment plant by reason of such violation, including increased costs for sewage treatment, sludge treatment and disposal and operation and maintenance expenses when such increased costs are the result of the discharger’s discharge. If the discharger discharges pollutants that cause the city to violate any condition of its NPIDES permit and to be fined by the United States Environmental Protection Agency or the state or federal government for such violation, the discharger shall be liable to the city for the total amount of the fine assessed against the city, including, without limitation, all legal, sampling, analytical and other associated costs and expenses. C. Termination of Service—Lien. In addition to the foregoing criminal sanctions and penalties detailed in other sections and not in any way a limitation thereof, persons alleged to be violating any provision of this chapter may be subject to termination of water and/or sewer service by the city upon being given ten days’ written notice by certified mail, return receipt requested, directed to such person’s address as last shown on the city records, informing them of the alleged violation and informing them that failure to correct such violation will result in termination of such service at the end of the ten-day period; provided, however, this section does not apply to termination of service due to nonpayment of the utility billing. Any work accomplished by customer request or necessary for maintenance, operation, and/or sampling of the private sewer, which may be billed for time, materials, equipment and overhead, or to repair damage caused by a customer and so billed, shall be subject to all applicable penalties including, but not limited to, lien and discontinuance of service, as provided for in CMC 15.10.120. D. RCW 35.67.350, Penalty for Sewer Connection Without Permission, as now in force or hereafter amended, added to or deleted from, is adopted by reference as part of this chapter. (Ord. 2077 § 1, 2001: Ord. 2051 § 1 (part), 2000). Page 41 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 15.10.350 Schedule of charges. A. User Charges. User charges levied in accordance with CMC 15.10.030 through 15.10.090 shall be as follows: Inside City Limits 2009 2010 2011 2012 2013 Single-Family Residential Monthly Base Rate $52.92 $56.96 $58.40 $60.15 $61.95 Low-Income Senior Citizen or Low-Income Totally Disabled $47.59 $51.22 $52.52 $54.10 $55.72 Usage: Lesser of Actual Water Use or Winter Cap (Per 100 Cubic Feet) $1.87 $2.01 $2.06 $2.12 $2.18 Multiple-Family Residential (includes trailer parks; see CMC 15.10.050(D)) First Dwelling $51.28 $55.40 $57.16 $58.87 $60.64 Each Additional $45.70 $49.37 $50.94 $52.47 $54.04 Usage: Lesser of Actual Water Use or Winter Cap (Per 100 Cubic Feet) $1.81 $1.96 $2.02 $2.08 $2.14 Domestic-Strength Commercial/Industrial Monthly Base Rate $17.79 $21.35 $22.12 $22.78 $23.46 Usage Per 100 Cubic Feet $9.48 $11.38 $11.79 $12.14 $12.50 Monthly Minimum $59.74 $71.69 $74.26 $76.49 $78.78 High-Strength Commercial/Industrial Monthly Base Rate—to be determined on a case-by-case basis N/A N/A N/A N/A N/A Usage Per 100 Cubic Feet—to be determined on a case-by- case basis N/A N/A N/A N/A N/A Outside City Limits 2009 2010 2011 2012 2013 Single-Family Residential Monthly Base Rate $79.37 $85.43 $87.59 $90.22 $92.93 Low-Income Senior Citizen or Low-Income Totally Disabled $71.39 $76.84 $78.78 $81.14 $83.57 Usage: Lesser of Actual Water Use or Winter Cap (Per 100 Cubic Feet) $2.81 $3.02 $3.10 $3.19 $3.29 Multiple-Family Residential (includes trailer parks; see CMC 15.10.050(D)) First Dwelling $76.93 $83.11 $85.74 $88.31 $90.96 Each Additional $68.56 $74.07 $76.42 $78.71 $81.07 Page 42 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl Outside City Limits 2009 2010 2011 2012 2013 Usage: Lesser of Actual Water Use or Winter Cap (Per 100 Cubic Feet) $2.71 $2.93 $3.02 $3.11 $3.20 Domestic-Strength Commercial/Industrial Monthly Base Rate $26.68 $32.02 $33.17 $34.17 $35.20 Usage Per 100 Cubic Feet $14.22 $17.06 $17.67 $18.20 $18.75 Monthly Minimum $89.62 $107.54 $111.40 $114.74 $118.18 High-Strength Commercial/Industrial Monthly Base Rate—to be determined on a case-by-case basis N/A N/A N/A N/A N/A Usage Per 100 Cubic Feet—to be determined on a case-by- case basis N/A N/A N/A N/A N/A For new sewer customers connecting or opening a utility account during the nonwinter months, or where there is no history of winter usage for an account, the lesser of the actual usage experienced by the new customer or the average residential usage quantity for all residential customers calculated for the most recent winter period shall be used to determine the monthly usage charge. In the case of low-income senior citizens or low- income totally disabled customers, the same shall apply except that the calculated average winter usage shall be based on low-income senior citizen and low-income totally disabled customer usage only. For new multiple-family residential accounts, the average winter usage per dwelling unit shall be ninety percent of that calculated from all residential usage. On January 1st of each year beginning in 2014, the rates shall be adjusted to reflect the annual percentage increase in the United States Consumer Price Index, All Urban Consumers (CPI-U) for November of the preceding year as shown in the release from the Bureau of Labor Statistics. Calculation of the change in the index is made by dividing the current index for November by the preceding index for November and subtracting one. B. Capital Facility Charge. 1. So that the property owners shall bear their equitable share of the cost of the wastewater system and as authorized in RCW 35.92.035, there shall be paid a capital facilities charge at the time the sewer permit is approved for a wastewater connection based on the size of the water meter (see exception in CMC 15.10.100 for certain required connections). When a request or requirement for a larger size water meter is made, the additional capital facilities charge for wastewater will be the difference between the old water Page 43 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl meter size and the new water meter size based on the current schedule of capital facilities charges. The capital facility charges shall be as follows: Capital Facilities Charge Effective January 1: Water Meter Size 2009 2010 2011 2012 2013 3/4 inch $4,932 $5,582 $6,232 $6,388 $6,548 1 inch $8,236 $9,322 $10,407 $10,667 $10,934 1 and 1/2 inch $16,424 $18,588 $20,753 $21,272 $21,804 2 inch $26,288 $29,752 $33,217 $34,047 $34,898 3 inch $52,625 $59,560 $66,496 $68,158 $69,892 4 inch $82,217 $93,052 $103,888 $106,485 $109,147 6 inch $164,384 $186,048 $207,713 $212,906 $218,229 8 inch $263,024 $297,689 $332,354 $340,663 $349,180 On January 1st of each year beginning in 2012, capital facility charges shall be adjusted to reflect the annual percentage increase of the Engineering News Record Construction Cost Index as published for November of the preceding year. Calculation of the change in the index is made by dividing the current index for November by the preceding index for November and subtracting one. 2. For projects not completed within one hundred eighty days after approval and where the permit has expired in accordance with CMC 15.10.145, the capital facilities charge shall be refunded to the applicant subject to a five percent processing fee. Latecomer, permit and inspection fees are non-refundable. Applicant shall be charged fee rates in effect at time of payment. 3. All capital facility fees collected shall be classified as restricted funds for capital system additions and improvements. (Ord. 2378 § 1, 2016: Ord. 2298 § 8, 2013: Ord. 2225 § 2, 2008: Ord. 2212 § 9 (part), 2008: Ord. 2199 § 1, 2007: Ord. 2179 § 3, 2006: Ord. 2134 § 1, 2004: Ord. 2069 § 1, 2001: Ord. 2051 § 1 (part), 2000). 15.10.360 Effective date of charges. A. Rates set forth in this chapter shall be in full force and effect with the January 2013 billing. Page 44 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl B. Capital facilities charges set forth in this chapter shall be in full force and effect January 2013. (Ord. 2298 § 9, 2013: Ord. 2225 § 3, 2008: Ord. 2212 § 9 (part), 2008: Ord. 2199 § 2, 2007: Ord. 2179 § 4, 2006: Ord. 2134 § 2, 2004: Ord. 2051 § 1 (part), 2000). Page 45 of 45Print Preview 10/15/2018https://www.codepublishing.com/WA/Centralia/cgi/menuCompile.pl 1 of 4 SERVICE AGREEMENT GRINDER PUMP SEWER SYSTEM FOR CUSTOMER This Agreement for a Grinder Pump Sewer System requested by Customer is entered into by and between The City of Centralia Wastewater Department (the City), a municipal corporation and NAME OF CUSTOMER. (“Customer”) for a grinder pump to provide sanitary sewer service to the property located at and commonly known as, PROPERTY ADDRESS (“Property”). Legal Description: Lot 1 of Centralia North II Commercial Condominium, according to the declaration thereof under Auditor’s File No. XXXX and the Condominium Plat recorded in Volume 1 of Condominiums, Page XX under Auditor’s File No. XXXX, records of Lewis County, Washington. TOGETHER WITH an easement for ingress, egress and utilities as disclosed by instrument titled, Street or Highway Easement, recording DATE, under Auditor’s File No.(s) XXXX and YYYY. Parcel #: XXXXX RECITALS WHEREAS, the City owns, operates and maintains a centralized sanitary sewer system; and WHEREAS, the City sanitary system is regulated by the rules and regulations of the Washington State Department of Ecology (DOE); and WHEREAS, Customer is currently connected to the City’s sanitary sewer system to receive sewer service from the City; and WHEREAS, the elevation and/or slope of the Property in relation to the location of the City’s sanitary sewer system requires Customer’s use of a low pressure sewer system commonly known as a grinder pump system (“ Grinder Pump”) in order to transport Customer’s sewage to the City’s sanitary sewer system; and WHEREAS, the Customer has installed a Grinder Pump with City approval of the design of the system, including materials and equipment. WHEREAS, the City has inspected and approved the installed Grinder Pump. NOW, THEREFORE, in consideration of the mutual promises and covenants contained herein, the City and Customer agree as follows: 1. As a condition of providing sanitary sewer service the Customer agrees to the following: 2 of 4 a. Grinder Pump maintenance: Customer agrees to contract with a licensed and bonded contractor to maintain and inspect every three (3) years their Grinder Pump in accordance with the DOE Criteria for Sewage Works Design 1, and Customer shall pay all cost of maintenance and repair directly to the contractor. The contractor must have a City of Centralia business license and be qualified and capable of performing such maintenance and repair. b. Customer agrees that the City and its representatives shall have the right to enter the Customer’s property with reasonable notice (except in the case of emergencies) to inspect the Grinder Pump as well as to stop discharge from the Grinder Pump in order to prevent contamination of state waters. c. Customer agrees that the City shall have the right to stop any discharges from the Grinder Pump in order to prevent contamination of state waters. 2. The City and Customer agree that, although the Grinder Pump is owned and maintained by the Customer, the Grinder Pump shall be regarded as an integral component of the City’s sanitary sewer system as required by the Rules of the Department of Ecology 2 and is not a part of the home plumbing for the Property. 3. Customer acknowledges and agrees that failure of Customer to pay all cost associated with the operation and maintenance of the Grinder Pump as set forth in the City’s Sanitary Sewer Rate Ordinance or failure of Customer to allow the City and its representatives to enter Customer’s property, as set forth in Section 1.b. above, shall be grounds for the disconnection of water and wastewater service to the Property. 4. The Customer consents to the jurisdiction of the State of Washington and any action to enforce any of the terms and provisions herein contained shall be brought in Lewis County, Washington and the laws of the State of Washington shall be controlling. 5. No waiver, alteration, or modification of any of the provisions of this Agreement shall be binding unless in writing and signed by a duly authorized representative of the City and Customer. 1 Criteria for Sewage Works Design (Section C1-10.4.1 thru C1-10.4.4) 2 Criteria for Sewage Works Design (Section C1-10 Alternative Systems) 3 of 4 6. This Agreement is not assignable by Customer. Upon termination of service to the Property or sale of property a new Customer desiring to receive water and/or wastewater service from the City shall be required to execute their own service agreement. 7. The Customer shall defend, indemnify and hold the City, its officials, employees and volunteers harmless from any and all claims, injuries, damages, losses or suits including attorney fees, arising out of or in connection with the performance of this Agreement, except for injuries and damages caused by the negligence of the City. 8. The Grinder Pump will be powered by Customer’s home electrical system. In the event that power service to the Grinder Pump is disrupted, Customer shall be responsible for taking measures to prevent the backup of wastewater on the Property. ENTERED INTO this the ______day of __________________, 20____. CITY: City of Centralia Public Works Wastewater Department By: _________________________ The City’s Representative CUSTOMER: By: See attached signature page Printed Name: Attached hereto 4 of 4 Signature Page to Service Agreement – Grinder Pump Sewer System for Customer CUSTOMER NAME By: XXXXX, its Manager By: _______________________________ NAME TITLE Signed: ___________ Appendix M Manhole Monitoring Form ( 0 APPENDIXH Manhole Monitoring Form Manhole No: Location Rim Elevation Pipe Invert Depth of Flow in Pipe <¼Full ¼Full ½Full ¾Full Full pipe Surcharged Date: Time: By: If Full Pipe or Greater, Distance Between Rim and Water Surface ft inches Other Observations: Weather/Rainfall Pipe Location Manhole Condition SE>/6-3n.ooc/982290006 98229000 H·1 Appendix N SEPA and SERP Documents City of Centralia General Sewer/ Facility Plan SEPA Checklist CITY OF CENTRALIA COMMUNITY DEVELOPMENT ENVIRONMENTAL CHECKLIST WAC 197-11-960 Environmental checklist. Purpose of checklist: The State Environmental Policy Act (SEPA), chapter 43.21C RCW, requires all governmental agencies to consider the environmental impacts of a proposal before making decisions. An environmental impact statement (EIS) must be prepared for all proposals with probable significant adverse impacts on the quality of the environment. The purpose of this checklist is to provide information to help you and the agency identify impacts from your proposal (and to reduce or avoid impacts from the proposal, if it can be done) and to help the agency decide whether an EIS is required. Instructions for applicants: This environmental checklist asks you to describe some basic information about your proposal. Governmental agencies use this checklist to determine whether the environmental impacts of your proposal are significant, requiring preparation of an EIS. Answer the questions briefly, with the most precise information known, or give the best description you can. You must answer each question accurately and carefully, to the best of your knowledge. In most cases, you should be able to answer the questions from your own observations or project plans without the need to hire experts. If you really do not know the answer, or if a question does not apply to your proposal, write "do not know" or "does not apply." Complete answers to the questions now may avoid unnecessary delays later. Some questions ask about governmental regulations, such as zoning, shoreline, and landmark designations. Answer these questions if you can. If you have problems, the governmental agencies can assist you. The checklist questions apply to all parts of your proposal, even if you plan to do them over a period of time or on different parcels of land. Attach any additional information that will help describe your proposal or its environmental effects. The agency to which you submit this checklist may ask you to explain your answers or provide additional information reasonably related to determining if there may be significant adverse impact. Use of checklist for nonproject proposals: Complete this checklist for nonproject proposals, even though questions may be answered "does not apply." IN ADDITION, complete the SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (part D). For nonproject actions, the references in the checklist to the words "project," "applicant," and "property or site" should be read as "proposal," "proposer," and "affected geographic area," respectively. City of Centralia Community Development 2 **** OFFICIAL USE ONLY **** Project #: Related Cases: Date Received: By: **** OFFICIAL USE ONLY **** Environmental Checklist 1. Applicant: Mr. Richard Dickinson Address: City of Centralia Public Works 1100 N. Tower Avenue Centralia, WA 98531 Phone: (360) 330-7512 Cell: N/A 2. Point of contact: Mr. Richard Dickinson Address: 1100 N. Tower Ave. 3. Owner: City of Centralia Address: 1100 N. Tower Ave. Centralia, WA 98531 Centralia, WA 98531 Phone: (360) 330-7512 Cell: N/A E-mail address: rdickinson@cityofcentralia.com Phone: (360) 330-7512 Cell: N/A E-mail address: N/A 4. Property address or location: 1101 Goodrich Road., Centralia, WA 98531 5. Quarter/Quarter Section/Township/Range: Section 26/Township 15N/Range 03W 6. Tax parcel number: (show all 12 digits) 023771001002 7. Total acres/square feet: WWTP is located within 263 acres. Improvements would occur within the existing site. 8. Permit type: General Sewer/Facility Plan Update 9. Zoning: RDD-10 10. Shoreline environment: Does not apply 11. Water body: Does not apply 12. Brief description of the project and project name: City of Centralia General Sewer/Facility Plan The City of Centralia General Sewer/Facility Plan is a planning document that includes elements of both a general sewer plan and a facility plan. It details how the City will provide service for population growth as it occurs, replace out of date or aging infrastructure, and provide adequate capacity at the Centralia Wastewater Treatment Plant. 13. Did you attend a presubmission conference for this project? Yes No If yes, when? 14. Estimated project completion date: Does not apply 15. List of all Permits, Licenses or Government Approvals Required for the Proposal (federal, state and local – including rezones): The plan must be approved by the Washington State Department of Ecology 3 City of Centralia Community Development Environmental Checklist 16. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. The General Sewer/Facility Plan describes the physical expansion and operational activities the City Wastewater Department will implement over the next 20 years to accommodate growth, replace aging infrastructure, and update the City of Centralia Wastewater Treatment Plant. 17. Do you know of any plans by others that may affect the property covered by your proposal? If yes, explain: No. 18. Proposed timing or schedule (include phasing, if applicable): The elements of the General Sewer/Facility Plan will be implemented over the next 20 years. 19. List any environmental information you know about that has been prepared, or will be prepared, that is directly related to this proposal: This is a non-project SEPA. Individual construction projects will go through separate review as they occur. Past documents include past project specific SEPA checklists, EIS for construction of the wastewater treatment facility (1999), General Sewer Plan (2000), General Sewer Plan update (2008), and various facility plans. 20. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain: No 21. List any government approvals or permits that will be needed for your proposal, if known. The General Sewer/Facility Plan must be approved by the Washington State Department of Ecology. 4 City of Centralia Community Development Environmental Checklist To be completed by Applicant Evaluation for Agency Use On B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site: Flat Rolling Hilly Steep slopes Mountainous Other: b. What is the steepest slope on the site (approximate percent slope)? The steepest slope in the service area is 40 percent. c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. General soil types found in the service area include: Spanaway, Newberg, Chehalis, Indianoia, and Nisqually series. Newberg fine sandy loam, Chehalis silt clay and Claquato silt loam are identified as prime farmland soils by the Natural Resource Council. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. Potentially unstable soils in areas proposed for sewer service will be subject to geotechnical investigations. e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill. Does not apply. f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. Does not apply. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? Does not apply. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: Does not apply. City of Centralia Community Development Environmental Checklist To be completed by applicant 2. Air a. What types of emissions to the air would result from the proposal (i.e., dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. Does not apply. Exhaust from construction equipment will be minimal. Some dust may result from construction activities. Pump Stations may produce small amounts of air emissions from emergency Generator operation. No odor generation is anticipated. b. Are there any off-site sources of emissions or odor that may affect your proposal? If so, generally describe. None known. c. Proposed measures to reduce or control emissions or other impacts to air, if any: Does not apply. 3. Water Evaluation for Agency Use Only a. Surface: 1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. Chehalis River, Dry creek. 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. Does not apply. 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. Does not apply. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known. No. 5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. Approximately 20 percent of the entire sewer service area lies within floodplains mapped by FEMA. 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. Discharge from the wastewater treatment facility is regulated under a site specific NPDES permit. Highly treated municipal wastewater is discharged to the Chehalis River. City of Centralia Community Development Environmental Checklist 6 b.Ground: 1)Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quantities if known. Does not apply. 2)Describe waste material that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage; industrial, containing the following chemicals. . . ; agricultural; etc.). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. Does not apply. c.Water runoff (including stormwater): 1)Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. Does not apply. 2)Could waste materials enter ground or surface waters? If so, generally describe. Does not apply. d.Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: Does not apply. 4.Plants a.Check types of vegetation found on the site: Deciduous tree: alder maple aspen other Evergreen tree: fir cedar pine other Shrubs Grass Pasture Crop or grain Wet soil plants:cattail buttercup bulrush, skunk cabbage, other Water plants: water lily eelgrass milfoil other Other types of vegetation b.What kind and amount of vegetation will be removed or altered? Does not apply. City of Centralia Community Development Environmental Checklist 7 To be completed by applicant Evaluation for Agency Use Only c. List threatened or endangered species known to be on or near the site. None known. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: Does not apply. 5. Animals a. Check any birds and animals which have been observed on or near the site or are known to be on or near the site: Birds: hawk heron eagle songbirds other: Mammals: deer bear elk beaver other: Fish: bass salmon trout herring shellfish other: b. List any threatened or endangered species known to be on or near the site. Bald eagles are known to nest in the vicinity of the Chehalis River. c. Is the site part of a migration route? If so, explain. Migratory waterfowl. d. Proposed measures to preserve or enhance wildlife, if any: Does not apply. 6. Energy and natural resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Construction equipment and sewer pump station emergency back-up generators will use petroleum based fuels. Pump stations normally use electrical power to operate. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No. c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: Does not apply. Energy conservation will be evaluated when individual components are designed and constructed. 7. Environmental health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste that could occur as a result of this proposal? If so, describe. Does not apply. City of Centralia Community Development Environmental Checklist 8 1) Describe special emergency services that might be required. Does not apply. Construction of future sewer improvements may encounter ground contamination from past uses. 2) Proposed measures to reduce or control environmental health hazards, if any: Does not apply. b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? Does not apply. Future construction projects will produce typical construction noise which will be addressed during those projects. 2) What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. Does not apply. Future construction projects will produce typical construction noise which will be addressed during those projects. 3) Proposed measures to reduce or control noise impacts, if any: Does not apply. 8. Land and shoreline use a. What is the current use of the site and adjacent properties? The current land use is wastewater facility. Adjacent properties include agriculture and single family on large parcels. b. Has the site been used for agriculture? If so, describe. Does not apply. The City of Centralia has agricultural areas where sewer service is provided and has facilities located on land that used to be considered agricultural. c. Describe any structures on the site. Does not apply. d. Will any structures be demolished? If so, what? Does not apply. City of Centralia Community Development Environmental Checklist 9 To be completed by Applicant Evaluation for Agency Use Only e. What is the current zoning classification of the site? Based upon information in the 2010 Amended Lewis County Comprehensive Plan, the area is currently zoned as RDD-10 (Rural Development District). This is a mixed-use zoning district that allows a number of different land uses such as single family residential, resource uses and limited types of commercial activity. RDD-10 allows a density of one dwelling unit per ten acres for subdivision purposes. f. What is the current comprehensive plan designation of the site? Site is located outside City limits of Centralia in unincorporated Lewis County. The Lewis County Comprehensive Plan designates the area as Rural – Open. g. If applicable, what is the current shoreline master program designation of the site? Does not apply. h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. There is a critical aquifer area within the City limits and urban growth area. i. Approximately how many people would reside or work in the completed project? Approximately 16,750 people live in Centralia. j. Approximately how many people would the completed project displace? None. k. Proposed measures to avoid or reduce displacement impacts, if any: None needed. l. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: None needed. 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low-income housing. Does not apply. b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing. Does not apply. c. Proposed measures to reduce or control housing impacts, if any: Does not apply. 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? Does not apply. b. What views in the immediate vicinity would be altered or obstructed? City of Centralia Community Development Environmental Checklist 10 Does not apply. c. Proposed measures to reduce or control aesthetic impacts, if any: Does not apply. 11. Light and glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? Does not apply. b. Could light or glare from the finished project be a safety hazard or interfere with views? Does not apply. c. What existing off-site sources of light or glare may affect your proposal? Does not apply. d. Proposed measures to reduce or control light and glare impacts, if any: Does not apply. 12. Recreation a. What designated and informal recreational opportunities are in the immediate vicinity? Does not apply. b. Would the proposed project displace any existing recreational uses? If so, describe. Municipal parks, trails c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: Does not apply. 13. Historic and cultural preservation a. Are there any places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe. Does not apply. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. Does not apply. c. Proposed measures to reduce or control impacts, if any: Does not apply. City of Centralia Community Development 11 Environmental Checklist To be completed by applicant Evaluation for Agency Use Only 14. Transportation a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any. Does not apply. b. Is site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? Does not apply. c. How many parking spaces would the completed project have? How many would the project eliminate? Does not apply. d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private). Does not apply. e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. Does not apply. f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. Does not apply. Not known at this time. g. Proposed measures to reduce or control transportation impacts, if any: Does not apply. 15. Public services a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe. Does not apply. b. Proposed measures to reduce or control direct impacts on public services, if any. Does not apply. 16. Utilities a. Circle utilities currently available at the site: electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic system, other. b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity that might be needed. Does not apply. City of Centralia Community Development 12 Environmental Checklist C.SIGNATURE Pursuant to RCW 9A.72.085, I declare under penalty of perjury under the laws of the State of Washington that the foregoing is true and correct. I understand that the lead agency is relying on them to make its decision. Signature: Date Submitted: Environmental Checklist submittal Requirements Fees: $200.00 Please make checks payable to: City of Centralia Site plan: Submit one copy of site plan on 11” x 17” paper. The plan must be clearly legible and contain pertinent information Supplemental reports: Include any applicable reports such as wetland report, storm water calculations, or traffic impact analysis City of Centralia - Community Development 118 W. Maple St. PO Box 609 Centralia, WA 98531 Phone: (360) 330-7662 City of Centralia Community Development 13 Environmental Checklist To be completed by applicant Evaluation for Agency Use Only D. SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (Do not use this sheet for project actions) Because these questions are very general, it may be helpful to read them in conjunction with the list of the elements of the environment. When answering these questions, be aware of the extent the proposal, or the types of activities likely to result from the proposal, would affect the item at a greater intensity or at a faster rate than if the proposal were not implemented. Respond briefly and in general terms. 1. How would the proposal be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? When implemented, the General Sewer/Facility Plan will provide public sanitary sewer services and treatment. Individual components of the General Sewer/Facility Plan will be implemented over 20 years. Construction will produce temporary emissions to air, noise, and disrupt traffic. Construction erosion control practices are required. We do not anticipate implementation of the plan to increase discharge to water since that is regulated under a NPDES permit. Proposed measures to avoid or reduce such increases are: Construction contracts will include controls and mitigation for air emissions, noise, traffic disruption, and erosion control. 2. How would the proposal be likely to affect plants, animals, fish, or marine life? The General Sewer/Facility Plan is designed to ensure wastewater is conveyed to the wastewater treatment plant and treated to standards that protect plants, animals, fish and marine life. It will also protect human health. Proposed measures to protect or conserve plants, animals, fish, or marine life are: During construction, measures would be implemented as required. 3. How would the proposal be likely to deplete energy or natural resources? The proposal does not deplete energy or natural resources. Proposed measures to protect or conserve energy and natural resources are: Does not apply. 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated (or eligible or under study) for governmental protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitat, historic or cultural sites, wetlands, floodplains, or prime farmlands? Implementation of the General Sewer/Facility Plan will protect all the elements listed. Proposed measures to protect such resources or to avoid or reduce impacts are: Implementation of the General Sewer/Facility Plan will protect all the elements listed. 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? The General Sewer/Facility Plan should not affect land and shoreline use. Proposed measures to avoid or reduce shoreline and land use impacts are: The General Sewer/Facility Plan and design of projects must be approved by the Washington state department of ecology; all necessary permits (federal, state, and local) will be obtained and identified mitigation measures implemented. 6. How would the proposal be likely to increase demands on transportation or public services and utilities? The General Sewer/Facility Plan should not affect the demands on transportation or public services except during construction of site specific improvements which will go through independent environmental review. Proposed measures to reduce or respond to such demand(s) are: Site specific improvements will go through independent environmental review. 7. Identify, if possible, whether the proposal may conflict with local, state, or federal laws or requirements for the protection of the environment. SEPA review for the General Sewer/Facility Plan was required by the Department of Ecology Wastewater Engineer. The proposal does not conflict with any local, state, or federal laws. All necessary permits (federal, state, and local) will be obtained and identified mitigation measures implemented. City of Centralia General Sewer/ Facility Plan SEPA Determination of Non-significance SEPA #:2019 0025 Date of Determination: March 2, 2019 FINAL DETERMINATION OF NONSIGNIFICANCE Description of proposal: The City of Centralia General Sewer/Facility Plan is a planning document that includes elements of both a general sewer plan and a facility plan. It details how the City will provide service for population growth as it occurs, replace out of date or aging infrastructure, and provide adequate capacity at the Centralia Wastewater Treatment Plant. Proponent: Rick Eaton, (360)330-7512, reaton@cityofcentralia.com Location of proposal: City Wide, Non-Project Related Lead agency: Centralia Community Development The lead agency for this proposal has determined that the update to the City of Centralia General Sewer Plan does not have a probable significant adverse impact on the environment with development conditions. An environmental impact statement (EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request. This DNS is issued under WAC 197-11-340(2). Responsible official: Jennifer Kreifels Position/title: Planner, City of Centralia - Community Development Phone: (360) 330-7684 Email: jkreifels@cityofcentralia.com Address: P.O. Box 609 Centralia, WA 98531 Signature:___________________________________________ You may appeal this determination to City of Centralia - Community Development, 118 W Maple, Centralia, WA 98531. All appeals must be filed with City of Centralia in writing with a $100.00 fee, submitted by 5:00 pm on March 23. You should be prepared to make specific factual objections. If you have any questions regarding the SEPA or appeal processes please contact the Responsible Official. The environment threshold determination is based on analysis of information contained in the following documents: Environmental Checklist, City of Centralia Sewer Plan Update. General Notes/Conditions: The issuance of a Determination of Nonsignificance does not constitute project approval. The proposal must comply with all applicable requirements of the City of Centralia, as well as all other local, state and federal requirements. Jennifer Kreifels Environmental Notes/Conditions: Department of Ecology, Southwest Regional Office: see attached letter dated March 1, 2019, and reads as follows. AIR QUALITY/GREENHOUSE GASES: Gail Sandlin (360) 407-6800 The sewage treatment plan does not discuss greenhouse gas emissions nor does the document discuss climate resilience strategies based on plant location which may or may not be significant. Ecology’s comments are based upon information provided by the lead agency. As such, they may not constitute an exhaustive list of the various authorizations that must be obtained or legal requirements that must be fulfilled in order to carry out the proposed action. If you have any questions or would like to respond to these comments, please contact the appropriate reviewing staff listed above. Community Development Department 118 W. Maple St. Centralia, WA 98531 (360) 330-7662 STATE OF WASHINGTON DEPARTMENT OF ECOLOGY PO Box 47775 Olympia, Washington 98504-7775 (360) 407-6300 711 for Washington Relay Service Persons with a speech disability can call 877-833-6341 March 1, 2019 Jennifer Keifels, SEPA Responsible Official City of Centralia Community Development Department PO Box 609 Centralia, WA 98531 Dear Jennifer Keifels: Thank you for the opportunity to comment on the revised determination of nonsignificance for the City of Centralia General Sewer/Facility Plan (2019 0025) as proposed by City of Centralia Public Works, Wastewater Division. The Department of Ecology (Ecology) reviewed the environmental checklist and has the following comment(s): AIR QUALITY/GREENHOUSE GASES: Gail Sandlin (360) 407-6800 The sewage treatment plan does not discuss greenhouse gas emissions nor does the document discuss climate resilience strategies based on plant location which may or may not be significant. Ecology’s comments are based upon information provided by the lead agency. As such, they may not constitute an exhaustive list of the various authorizations that must be obtained or legal requirements that must be fulfilled in order to carry out the proposed action. If you have any questions or would like to respond to these comments, please contact the appropriate reviewing staff listed above. Department of Ecology Southwest Regional Office (MLD:201900820) cc: Gail Sandlin, AQP/GHG Rick Eaton, City of Centralia Public Works (Proponent) City of Centralia WWTP Upgrades SEPA Checklist City of Centralia WWTP Upgrades SERP Crosscutter SERP CROSS CUTTER DOCUMENTATION The following sections are based upon Ecology’s Combined Funding Program: Environmental Review Guidance specific to the Federal Cross Cutters not addressed under SEPA. The study area for the proposed action is the area associated within the existing WWTP facility where construction and operation would occur (Figure 1-1). The City of Centralia shall comply with the criteria and mitigation conditions for the project as documented in the October 2017 technical memorandum, City of Centralia WWTP – Phase 1 Improvements Design for the City’s WWTP project. This shall include any associated criteria, plans, or permits identified as required during the construction of the proposed action as a result of new or more detailed information. Additionally, standard construction mitigation measures to control any temporary impacts (i.e., transportation, earth, air quality, water quality, and noise) will be included in design and construction documents/permits prepared for the proposed action. The following provides information on the Federal Cross Cutters and provides information on the proposed action would not result in any impacts during construction or operation because the elements addressed by the cross cutters are either not located in the project area or would not be affected by the construction and operation of the proposed action. Clean Air Act. The proposed action is not within a Washington State designated maintenance or non- attainment area. The proposed action would result in some short-term exhaust and particulate emissions would be generated by construction equipment and activities. Vehicles entering and leaving construction sites would also generate dust. These impacts are temporary and would end once construction has been completed. Construction-related mitigation includes measures to minimize the generation of dust during excavation, grading, and filling earth materials includes watering exposed surfaces, covering loads, and wheel washers for trucks, if applicable. During operation of the proposed action there would be no impacts and no mitigation would be required. Coastal Zone Management Act. Lewis County is not within a coastal zone. In addition, the proposed action is not within any shorelines of the state that would trigger a shoreline permit. Endangered Species Act. There are no threatened or endangered species within the WWTP facility and construction and operation would not result in any impacts. Construction would be short-term in nature and would only require the removal of grass. All construction activities would meet the applicable city and county requirements regarding stormwater management. Environmental Justice. The proposed action is within the boundaries of the existing WWTP facility where there are no residents. Construction and operation is within the existing facility and does not result in any disproportionately high and adverse effects to minority, low-income, or tribal populations. Farmland Protection Policy Act. The proposed action does not convert any farmland to nonfarm uses. The site is located on engineered fill material and the site was converted to the WWTP facility when it was constructed in 2002. Any impacts to prime farmland were identified as part of the environmental documentation completed prior to the construction of the WWTP facility. Because the proposed action is within areas of engineered fill it does not result in any impacts. The new impervious area associated with the Phase I project would be located on engineered fill that was compacted to at least 90-percent modified Proctor at the time of the WWTP’s construction in 2002. Floodplain Management. The proposal lies within the 500-year floodplain. Construction of the WWTP site in 2002 elevated the site above the 100-year floodplain on engineered fill, but the site is still shown within the floodplain on existing maps. In 2012, a Letter of Map Revision Based on Fill Determination was accepted by the Federal Emergency Management Agency (FEMA); it documents the removal of the site from the 100-year floodplain area. The project is now located within Zone B (moderate flood hazard areas – between the limits of the base flood and the 0.2-percent-annual- chance (or 500-year) flood). There are no shorelines within the study area that would be affected. National Historic Preservation Act. A Cultural Resources Technical Report was prepared in 2002 as part of the EIS that addressed the history of the area within and surrounding the WWTP. As part of the cultural resources investigation, a field survey was conducted within the boundaries of the WWTP site which include subsurface testing. No cultural resources were identified during testing; however, the report recommended, and the Washington State Department of Archaeology and Historic Preservation concurred, the preparation of a Cultural Resource Mitigation Monitoring Plan (CRMMP) to assure that significant cultural resources that could be encountered during construction are protected. The CRMMP covered the entire project area which included the new WWTP facility. The CRMMP addresses the communication protocols, project monitoring, and documentation. During the construction of the new WWTP in 2002 a precontact archaeological site was discovered below the ground surface (identified as site 45LE532). The site contained intact features at depths between 80 cm and 200 cm below the existing surface. Although the site has not been formally evaluated for listing in the National Register of Historic Places (NRHP), it should be considered a potentially NRHP-eligible site. If construction requires excavation within the known boundaries of the site 45LE532, a formal determination of eligibility for listing in the NRHP must be completed. If the site is considered NRHP-eligible, the CRRMP recommends appropriate mitigation strategies that tie directly to the site’s significance. This may include development and implementation of a data recovery plan as outlined in the CRMMP. If the installation of new tanks requires soil disturbance within native soils outside the known boundaries of the site 45LE532, the mitigation measures identified in the CRMMP will be implemented including monitoring during construction by a professional archeologist. Safe Drinking Water Act. The project area lies within the Chehalis River basin and is not within any EPA designated sole source aquifers. No construction activities would occur within any surface waters, and all construction would adhere to the applicable city and county codes. Ground water resources are not anticipated to be impacted as a result of the construction or operation of the proposed action. The proposed action would add approximately 0.06 acres of new impervious surface associated with pavement, gravel roadway, building roof and electrical trench. During construction, standard best management practices (BMPs) would be employed to prevent erosion including the use of silt fences, straw bales, or plastic sheets during grading activities or stockpiling of materials. During operation stormwater runoff would be treated prior to discharge and would not impact water quality, therefore no mitigation is required. Essential Fish Habitat. The proposed action is located within the existing WWTP property and about 2,000 feet east of the Chehalis River. All construction activities would meet the applicable city and county requirements regarding stormwater management. Operation would collect and treat stormwater prior to discharge. Wetland Protection. The area where the proposed action would be located currently consists of mowed grass and existing impervious surfaces. There are no wetlands within the existing WWTP facility because the facility is located on fill material. Wild and Scenic Rivers Act. There are no designated Wild and Scenic Rivers located in the project area. City of CentraliaPhase I SEPA Checklist Figure 1-1 VICINITY MAP City of Centralia WWTP Upgrades SEPA Determination of Non-Significance SEPA #: 2017 0463 Date: October 10, 2017 NOTICE OF APPLICATION AND DETERMINATION OF NONSIGNIFICANCE Description of proposal: Upgrades to the Wastewater Treatment Plan in two phases. Phase I: Complete State Environment Review Process with Cross Cutter (SERP) documentation, add mixed liquor recirculation pumps in the existing aeration basins, construct two waste activated sludge (WAS) storage tanks, add two new WAS feed pumps, install two new positive-displacement blowers and expand the Blower Building to house electrical and control needs associated with the upgrades. Phase II upgrades will be reviewed under separate application at a future date. Proponent: City of Centralia Public Works Richard Dickinson, Wastewater Division 1100 N Tower Avenue Centralia, WA 98531 Location of proposal: 1101 Goodrich Road Date of Application: October 4, 2017 Date of Notice of Completeness: October 5, 2017 Lead agency: Centralia Community Development Project Permits: SEPA, Fill & Grade, Building and Electrical Environmental Documents on file: SEPA checklist, ch2m Hill Engineers technical memo. The City of Centralia Community Development Dept. has determined this project does not have a probable significant adverse impact on the environment. An Environmental Impact Statement (EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other information on file with the City. The proposal may include mitigation measures under applicable codes and the project review process may incorporate or require mitigation measures regardless of whether an EIS is prepared. This information is available to the public upon request. This DNS is issued under WAC 197-11-340(2); the City of Centralia will not act on this proposal for 15- days from the date of last publication. Comments are due by: November 3, 2017. Responsible official: Hillary Hoke Position/title Planner, City of Centralia - Community Development Phone: (360) 330-7684 Email: hhoke@cityofcentralia.com Address: PO Box 609, Centralia WA 98531 The complete application may be viewed at the Community Development Dept. located at 118 W Maple, Centralia, WA 98531, during regular business hours, M-F. Any person(s) may comment on the proposal, in writing, via mail or email at the addresses above. You may appeal this determination to City of Centralia - Community Development. All appeals must be filed in writing, with the appropriate fee, by 5:00 pm on November 13, 2017. You should be prepared to make specific factual objections. If you have any questions regarding the SEPA or appeal processes please contact the Responsible Official. Appendix O City of Centralia Sanitary Sewer Design and Development Guidelines CHAPTER 3 SANITARY SEWER Section Page 3.01 General...............................................................................................................1 3.02 Required Separation between Water and Sanitary Sewer Mains ......................1 3.03 Staking...............................................................................................................1 3.04 Trench Excavation.............................................................................................2 3.05 Backfilling .........................................................................................................3 3.06 Street Patching and Restoration.........................................................................3 3.07 Testing ...............................................................................................................3 3.08 Gravity Sewer: General .....................................................................................5 3.09 Gravity Sewer Design Standards.......................................................................5 Process to Obtain Sewer Service.......................................................................6 3.10 Gravity Main Line .............................................................................................6 3.11 Connection to Existing System..........................................................................7 3.12 Manholes............................................................................................................8 3.13 Gravity Sewer Slope..........................................................................................9 3.14 Increasing Size, Gravity Sewer........................................................................10 3.15 High Velocity Protection.................................................................................10 3.16 Drops................................................................................................................10 3.17 Cleanouts .........................................................................................................10 3.18 Laterals.............................................................................................................11 3.19 Lift Station Design Standards..........................................................................11 3.20 Pressure Sewer (Force Main) General.............................................................15 3.21 Pressure Sewer Design Standards....................................................................15 3.22 Force Main.......................................................................................................16 3.23 Pressure Sewer Surge Protection.....................................................................16 3.24 Pressure Sewer Air/Vacuum Valves................................................................16 3.25 Force Main Drain.............................................................................................16 3.26 Pressure Sewer Thrust Blocking......................................................................17 3.27 Force Main Termination..................................................................................17 3.28 Pump Station Upgrades....................................................................................17 3.29 Residential Grinder Pumps..............................................................................17 3.30 Vehicle and Equipment Washwater Discharge................................................22 List of Drawings ..............................................................................................24 Centralia Guidelines 10/08 Revised 2/09 Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-1 Revised 2/09 CHAPTER 3 SANITARY SEWER 3.01 General Sanitary sewer refers to wastewater derived from domestic, commercial and industrial pretreated waste to which storm, surface, and ground water are not intentionally admitted. Pretreatment of industrial and commercial wastes shall follow all the requirements as set forth by the Washington State Department of Ecology (DOE), as administered by the Wastewater Department (Centralia Utilities). These requirements are not included herein (see CMC). Any extension of City of Centralia's sanitary sewer system must be approved by the City of Centralia and must conform to the City of Centralia's Facilities Plan and General Sewer Plan, Washington State Department of Ecology (DOE) and Washington State Department of Health (DOH) requirements. Within the corporate City limits where a public sewer is within 200 feet, it must be used (CMC). In the endangered aquifer areas on Waunch and Fords Prairies, this requirement has also been legislated by the Lewis County Board of Health. All vehicle and equipment wash facilities shall be zero discharge closed loop water recycling. The City will not allow discharge into the municipal sewer system. Anyone who wishes to extend or connect to the City's sewer system should contact the Community Development Department for Water/Wastewater Application form. Prior to the release of any water meters all Public Works improvements must be completed and approved, all easements shall be recorded, all bonds received, and all applicable fees must be paid. See Section 1.04 for definitions of specific sewers. Maintenance of the sanitary sewer lateral shall be the responsibility of the property owner. 3.02 Required Separation Between Water and Sanitary Sewer Mains See Section 2.13 for requirements regarding sewer and water separation. 3.03 Staking All surveying and staking shall be performed by an engineering or surveying firm capable of performing such work. The engineer or surveyor directing such work shall be licensed by the State of Washington. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-2 Revised 2/09 A pre-construction meeting shall be held with the City Engineer before staking begins. All construction staking shall be inspected by the City Engineer prior to construction. Staking shall be maintained throughout construction. The minimum staking of sewer lines shall be as follows: 3.03.1 Centerline alignment must be staked with cuts and/or fills to flowline every 25 feet. 3.03.2 Manholes must be staked with hubs to include invert elevations of all pipes and top of rim elevations to finished grade. 3.04 Trench Excavation 3.04.1 Clearing and grubbing where required shall be performed within the easement or public right-of-way as permitted by the City and/or governing agencies. Debris resulting from the clearing and grubbing shall be disposed of by the owner or contractor in accordance with the terms of all applicable permits and/or regulations. 3.04.2 Trenches shall be excavated to the line and grade on the plan approved by the City. The minimum depth of cover measured from finished surface grade to the top of the pipe shall be 36 inches. Except for unusual circumstances where approved by the City, the trench sides shall be excavated vertically and trench width shall be no wider than the pipe outside diameter plus 24 inches. The trench shall be kept free of water. Surface water shall be diverted so as to not enter the trench. The developer/contractor shall maintain sufficient dewatering equipment on the job site to insure that these provisions are met. 3.04.3 The contractor shall perform all excavation so that all boulders, rocks, roots and other obstructions shall be entirely removed or cut out of the width of the trench and to a depth of 6 inches below the sewer main grade. The base of the trench must be solid so in some cases the contractor may have to over excavate to obtain a satisfactory base. 3.04.4 Trenching and shoring shall not proceed more than 40 feet in advance of the pipe laying, without approval of the City, and shall be in conformance with Washington Industrial Safety and Health Administration (WISHA) and Occupational Safety and Health Administration (OSHA) safety standards. 3.04.5 The bottom of the trench shall be finished to grade in such a manner that the pipe will have bearing along the entire length of the barrel. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-3 Revised 2/09 3.05.6 The backfill shall be placed in uniform horizontal lifts, not to exceed 1-foot in depth and compacted to the following percentage of maximum dry density; 90 percent below 2-foot depth and 95 percent in the top 2 feet as determined by ASTM 3.04.6 The contractor shall maintain the presence of a "competent person" as defined by the Washington State Department of Labor and Industries (L&I), when any trench excavation and backfill work is being done at the project site. 3.05 Backfilling 3.05.1 Backfilling shall not commence until the pipe installation has been inspected and approved by the City Inspector. 3.05.2 Backfilling shall closely follow pipe installation so that no more than 40 feet is left open without approval of the City. 3.05.3 The backfill in the pipe zone shall be bedding material conforming to Section 9-3.12(3) of the WSDOT Standard Specifications. 3.05.4 If foundation material is required below the pipe zone, the material shall conform to Section 9-03.17 Class B of the WSDOT Standard Specifications. 3.05.5 The backfill between the bedding and road ballast may be native if the native material is approved by the City. If the native material is deemed unsuitable, then select import backfill conforming to Section 9-03.19 of the WSDOT Standard Specifications. D1557-80 (Modified Proctor). Compaction shall be by mechanical means. 3.05.7 At the conclusion of each day the trench shall be totally backfilled or steel plates shall be used so that there is no open excavation over night. 3.06 Street Patching and Restoration See Sections 4.15 and 4.16 for requirements regarding street patching and trench restoration. 3.07 Testing Prior to acceptance and approval of construction, the following tests shall apply to each type of construction. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-4 Revised 2/09 3.07.1 Gravity Sewer Air Test: Prior to acceptance of the project, the gravity sewer pipe shall be subject to a low pressure air test per WSDOT/APWA Standard Specifications. The contractor shall furnish all equipment and personnel for conducting the test under the observation of the City Inspector. The testing equipment shall be subject to the approval of the City. Immediately following the pipe cleaning, the pipe installation shall be tested with low pressure air. The contractor shall make an air test for his own purposes prior to notifying the City to witness the test. The acceptance air test shall be made after the trench is backfilled and compacted and the roadway section is completed to subgrade. All wyes, tees, and end of side sewer stubs shall be plugged with flexible joint caps, or acceptable alternates, securely fastened to withstand the internal test pressures. Such plugs or caps shall be readily removable and their removal shall provide a socket suitable for making a flexible jointed lateral connection or extension. 3.07.2 Gravity Sewer TV Inspection: Testing of the sewer main shall include a television inspection at the contractor's expense. Television inspection shall be done after the air test has passed and before the roadway is paved. Immediately prior to a television inspection, enough water shall be run down the line so it comes out the lower manhole and the line is flushed clean. All debris collected after flushing shall be removed and disposed of by the contractor at their expense. It shall be disposed of at a legal dump site for this type of waste. A written log shall accompany the videotape. The audio portion of the tape will identify any laterals and defects seen. On screen counter footage shall be reset in each manhole. Each manhole shall be identified by location and numbering consistent with the plans. Acceptance of the line will be made after the television inspection tape has been reviewed and approved by the City. Any tap to an existing system needs to be televised as well. 3.07.3 Manhole Test: A vacuum test of all manholes is also required. The vacuum test shall be performed by creating a vacuum of 10 inches of mercury. If the vacuum does not drop in excess of 1-inch of mercury over the specified time period, the manhole passes test. The specified time period for every 2 feet of manhole depth is 5 seconds for a 48-inch diameter manhole and 6.5 seconds for a 60-inch manhole. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-5 Revised 2/09 3.07.4 Force Main Hydrostatic Test: Prior to acceptance of the project, the pressure line and service lines shall be subjected to a hydrostatic pressure test of 100 psi for 15 minutes. Any leaks or imperfections developing under this pressure shall be remedied by the contractor. No air will be allowed in the line. The main shall be tested between valves. Insofar as possible, no hydrostatic pressure shall be placed against the opposite side of the valve being tested. The pressure test shall be maintained while the entire installation is inspected. The contractor shall provide all necessary equipment and shall perform all work connected with the tests. Tests shall be made after all connections have been done. This is to include any and all connections as shown on the plan. The contractor shall perform all tests to assure that the equipment to be used for the test is adequate and in good operating condition and that the air in the line has been released before requesting the City to witness the test. The contractor shall give the City a 48 hours notification of the test. 3.07.5 Wet Well Test: A water test for all wet wells in accordance with the manhole test for gravity sewer shall be required. 3.07.6 Force Main Mandrel Test: A mandrel test of all force main, in accordance with Section 7-17.3(2)G of the WSDOT/APWA Standard Specifications is required. 3.07.7 Pump Station Tests: Pump operation, alarms, and electrical inspection of all lift stations is required. 3.08 Gravity Sewer General All sewers shall be designed as a gravity system whenever physically and/or economically feasible. Addition of new pumping stations is undesirable. 3.09 Gravity Sewer Design Standards The design of any sewer extension/connection shall conform to City Standards, DOE's "Criteria of Sewage Works Design" and any applicable standards as set forth herein and in Sections 1.02 and 1.06. The layout of extensions shall provide for the future continuation of the existing system as determined by the City. See also Section 1.18 for utility extension information. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-6 Revised 2/09 New gravity sewer systems shall be designed on the basis of an average daily per capita flow of sewage of not less than 100 gallons per day. See the DOE "Criteria" table: Design Basis for Sewage. The numbers are assumed to cover normal infiltration, but an additional allowance shall be made where conditions are unfavorable. Generally, laterals and submain sewers should be designed to carry, when running full, not less than 400 gallons daily per capita contribution of sewage. When deviations from the foregoing per capita rates are used, a description of the procedure used for sewer design shall be submitted to the Engineering Department for review and approval. The General Notes found in the Standard Detail Section shall be included on any plans dealing with sanitary sewer design and/or construction. 3.10 Gravity Main Line 3.10.1 Sewer mains shall be sized for the ultimate development of the tributary area. Nothing shall preclude the City from requiring the installation of a larger sized main if the City determines a larger size is needed to meet the requirements for future service. The minimum size for submains and mains shall be 8-inch inside diameter. The minimum size for a lateral within the street right-of-way shall be 6-inch inside diameter. The design of the sewer line/system is subject to all other requirements as noted in this Chapter. 3.10.2 Main line sewers must be constructed using materials conforming to one of the following: PVC pipe 6-inch to 15-inch diameter must meet either ASTM D 3034, SDR 35 solid wall pipe, or ASTM F 794 for solid seamless profile pipe. PVC pipe 18-inch to 27-inch diameter shall conform to ASTM F 679 Type 1 only. Ductile Iron, conforming to Section 9-05.13, WSDOT/APWA Standard Specifications and ANSI A21.51 or AWWA C151, and cement mortar lined. Minimum thickness shall be Class 51. All joints for PVC pipe shall conform to ASTM D 3212 with rubber gaskets conforming to ASTM F 477. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-7 Revised 2/09 3.10.3 Gravity sewer will typically have a minimum depth of 5 feet to provide gravity service to adjoining parcels, adequate head room within manholes for maintenance personnel, future areas to be served, and vertical clearance between water and sewer lines. Actual depth will be determined by slope, flow, velocity, and elevation of existing system. 3.10.4 All building sewer connections to the main shall be made with a sanitary tee (wye) connection. Backflow prevention devices shall be provided as required by the Uniform Building Code (UBC) and Uniform Plumbing Code (UPC), W.A.C. 51.50. All new mains connecting to existing mains shall require the installation of a new manhole if not made at an existing manhole. 3.11 Connection to Existing System 3.11.1 At connection to existing system, all new sewer connections shall be physically plugged until all tests have been completed and the City approves the removal of the plug. 3.11.2 Connection of new pipe lines to existing manholes shall be accomplished by using provided knock-outs. Where knock-outs are not available, the manhole shall be core drilled for connection. The transition of connecting channels shall be constructed so as not to interrupt existing flow patterns. All connections shall utilize cor-seal grouting material. Manhole shall be vacuum tested after connection. 3.11.3 Connection of a pipe line to a system where a manhole is not available shall be accomplished by pouring a concrete base and setting manhole sections. The existing pipe shall not be cut into until approval is received from the City. 3.11.4 Connections to manholes requiring a drop shall follow the criteria as outlined in Section 3.16. 3.11.5 Connections where an existing stub-out is not available or where a new building sewer is the same size as the existing main shall be accomplished by the installation of a new manhole. 3.11.6 Taps shall be done by use of a core drill and shall not be allowed to protrude into the existing main. The City shall be notified two (2) working days prior to any tap of a City sewer and a City Inspector shall be present to witness the tap. At the City’s option, the City will install a tap for a fee after the contractor provides L&I acceptable access to the site. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-8 Revised 2/09 3.12 Manholes Precast manholes shall meet the requirements of ASTM C 478 with either a precast base or a cast-in-place base made from 3000 psi structural concrete. Manholes shall be Type 1, 60- inch diameter minimum. The minimum clear opening in the manhole frame shall be 24 inches. Joints shall be rubber gasketed, conforming to ASTM C 443 and shall be grouted from the inside. Lift holes shall be grouted from the outside and inside the manhole. Manholes constructed of other materials may be approved by the City Engineer, provided they meet the requirements of Section 2.318 of the DOE "Criteria for Sewage Works Design". Material specifications need to be submitted for review before an alternate material will be considered, See standard drawings 3-02 and 3-03. Eccentric manhole cones shall be offset so as to not be located in the tire track of a traveled lane. Manhole frames and covers shall be cast iron castings marked "Sewer", conforming to the requirements of ASTM A-30, Class 25, and shall be free of porosity, shrink cavities, cold shuts or cracks, or any surface defects which would impair serviceability. They shall be bolt down water tight type 2 frame and covers in accordance with WSDOT Standard Plan B-30.70-01. Any variation from this type of frame and cover must be approved by the City Engineer. Repairs of defects by welding or by use of smooth-on or similar material will not be permitted. Manhole rings and covers shall have machine-finished or ground-on seating surfaces so as to assure non-rocking fit in any position and interchangeability. All manholes shall be equipped with a PRECO sewer guard watertight manhole insert or approved equal. Where lock-type castings are called for, the casting device shall be such that the cover may be readily released from the ring and all movable parts shall be made of non-corrodible materials and otherwise arranged to avoid binding. All casting shall be covered with a bituminous coating prior to delivery to the job site. Safety steps shall be fabricated of polypropylene conforming to the ASTM D-4101 specification, injection-molded around a 0.5-inch ASTM A-615 grade 60 steel reinforcing bar. Steps shall project uniformly from the inside wall of the manhole. Steps shall be installed to form a continuous vertical ladder with rungs equally spaced in 12-inch centers. Generally, gravity sewers shall be designed with straight alignment between manholes. Curved alignment may only be permitted when conditions warrant and with the advance approval of the City Engineer and the Centralia Utilities. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-9 Revised 2/09 Manholes shall be provided at a maximum of 400-foot intervals, at intersections, and at changes in direction, grade, or pipe size. (See also Section 3.14.) Minimum slope through the manhole shall be 0.10-foot from invert in to invert out. Manholes shall have a minimum diameter of 60 inches. All exterior joints of the manhole shall be sealed with WrapidSeal as manufactured by Canusa Corrosion Protection and Sealing. This includes the joint between manhole sections and the entire set of adjustment rings. It shall be applied in accordance with the manufacturer’s recommendation. For pipes 15-inch diameter and larger, the size of the manhole shall be approved by the City Engineer. 3.13 Gravity Sewer Slope All sewers shall be designed and constructed to give mean velocities, when flowing full, of not less than 2 feet per second based on Manning's formula using an "n" value of 0.013. Use of other practical "n" values may be permitted by the City if deemed justifiable on the basis of research or field data submitted. The following minimum slopes shall be provided; however slopes grater than these are desirable. Sewer Size, Minimum % Slope, Inches % (Feet per 100 Feet) 8 0.40 (0.0040 Ft/Ft) 10 0.28 (0.0028 Ft/Ft) 12 0.22 (0.0022 Ft/Ft) 14 0.17 (0.0017 Ft/Ft) 15 0.15 (0.0015 Ft/Ft) 16 0.14 (0.0014 Ft/Ft) 18 0.12 (0.0012 Ft/Ft) 21 0.10 (0.0010 Ft/Ft) 24 0.08 (0.0008 Ft/Ft) 27 0.07 (0.0007 Ft/Ft) 30 0.06 (0.0006 Ft/Ft) 36 0.05 (0.0005 Ft/Ft) Such decreased slopes will only be considered where the depth of flow will be 30 percent of the diameter or greater for design average flow. Whenever such decreased slopes are proposed, the design engineer shall furnish with the plans his/her computations of the depths of flow in such pipes at minimum, average, and daily or hourly rates of flow. Larger pipe Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-10 Revised 2/09 size shall not be allowed to achieve lesser slopes. Sewers shall be laid with uniform slope between manholes. 3.14 Increasing Size, Gravity Sewer Manholes shall be provided where pipe size changes occur. Where a smaller sewer joins a larger one, the invert of the larger sewer should be lowered sufficiently to maintain the same energy gradient. An approximate method for securing these results is to place the 80 percent depth point of both sewers at the same elevation. 3.15 High Velocity Protection Where velocities greater than 15 feet per second are expected, special provisions such as thrust blocking and piping materials shall be made to protect against displacement by erosion and shock, and the presence of hydrogen sulfide gas. 3.16 Drops Straight grades between invert out of last manhole and connection to existing are preferred over drops whenever possible. Care must be taken when designing steep grades so as not to create a situation of excessive velocity or excavation. Grade changes associated with "sweeps" shall not be allowed. An inside drop connection shall be provided for a sewer entering a manhole at an elevation of 24 inches or more above the manhole invert. Where the difference in elevation between the incoming sewer and the manhole invert is less than 24 inches, the invert shall be filleted to prevent solids deposition. Inside drop structures shall be constructed per standard drawing number 3-06. Outside drop structures shall be constructed per standard drawing number 3-05. Outside drops will only be allowed in special cases by the City Engineer. 3.17 Cleanouts Cleanouts are not an acceptable substitute for manholes. However, they may be used in lieu of manholes at the end of 8-inch diameter lines of not more than 150 feet in length. Location of cleanouts for building sewers are governed by the UPC. All cleanouts in City right-of-way shall be extended to grade and a 3-foot square by 4-inch thick concrete pad shall be installed around all cleanouts that are not in the pavement area. See standard drawing 3-04. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-11 Revised 2/09 3.18 Laterals A lateral refers to the extension from a building sewer, beginning 3 feet outside the outer foundation wall at the structure to the sanitary sewer main. Building sewers from the main to the right-of-way line shall be a minimum of 6-inch in diameter. Maintenance of the entire building sewer is the responsibility of the property owner. The portion of line on private property shall be a minimum of 4-inch diameter for single-family and 6-inch diameter for duplex, commercial and industrial facilities. No laterals shall be connected directly to a manhole. Prior to connection of a building sewer to the public sewer a side sewer permit must be obtained from the City. Design criteria for a building sewer are covered by the UPC and the C.M.C. Chapter 15.10. Acceptable pipe material is PVC or ductile iron, as specified in Section 3.10.2. Inspection of the building sewer is the responsibility of the Wastewater Department (Centralia Utilities). Testing and inspection procedures are similar to those for main installation (excluding television inspection). 3.19 Lift Station Design Standards The design of any lift station shall conform to City Standards, DOE's "Criteria for Sewage Works Design" and applicable standards as set forth herein and in Sections 1.02 and 1.06. Each lift station shall be evaluated by the City Engineer for buoyancy resistance using site specific soil and groundwater information. The following equipment and special modifications are standard requirements for all permanent wastewater lift stations constructed for the City of Centralia wastewater collection system. Lift stations shall be landscaped appropriately. The following are minimum standards and are not all inclusive. 3.19.1 The proponent is required to provide the City of Centralia a fee simple site outside existing right-of-way for construction of the lift station. The site shall have sufficient area with dimensions that allow for easy and safe access to the lift station. 3.19.2 A concrete slab 6 inches in depth shall surround the pump station wet well, with a minimum of 2 feet side exposure for all openings. 3.19.3 An access road that will support 20,000 pound axle loads throughout the year shall be provided from the nearest public road to the station, to allow for maintenance of the station. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-12 Revised 2/09 3.19.4 Wet well shall be provided with a permanent attached, full depth, internal, polypropylene access ladder. 3.19.5 Station entry access shall be keyed to match all other City stations. The Best Lock key system shall be supplied for all other lock points and padlocks; a blank tumbler shall be supplied and the City will key the desired code. 3.19.6 Safety guards shall be provided for all exposed drive lines and couplings. 3.19.7 Spare parts shall be provided as recommended by the manufacturer, with a minimum of one spare impeller, one complete set of seals, filters, and one set of volute gaskets. Four (4) complete sets of O & M Manuals, and a list of the nearest dealers for spare parts and repairs shall be provided prior to acceptance. 3.19.8 The pumps, motors, and wet well shall be in compliance with current engineering practices. They shall be fully compatible as an assembly, and shall be engineered for the specific site. They shall be submersible pumps with stainless steel guide rails. There shall be a pressure gauge for the discharge pipe from each pump. The pumps shall be manufactured by Vaughn or approved by the City. All bolts, chains, and brackets shall be stainless steel. 3.19.9 The station shall be designed to have an isolation valve located in the discharge line no less than 12 pipe diameters from the wet well. Check valves shall have external arms to allow for back flushing. The check valve shall be as manufactured by Waterous and the isolation valve shall be a Dezuric plug valve with a quarter turn shut off. There shall also be a bypass pumping port included with a camloc fitting. 3.19.10 The isolation and check valve shall be housed in a precast concrete vault. The vault shall have a minimum size of 6-foot by 6-foot inside dimension. There shall be a bottom drain that drains back into the wet well. The vault hatch shall be a minimum of 3 feet (L) x 4 feet (W). The hatch shall be supplied with a safety net. 3.19.11 City water shall be provided to the station for hose down and pump seal supply. An approved backflow prevention device shall be provided on the water supply line to protect the public water system. The backflow device shall be tested and certified by a State-Certified Backflow Tester prior to acceptance of the system. The cost of the backflow prevention device, water service, and testing will be the developer’s responsibility. If the station is located in the 100-year flood plain, all equipment, controls, and accessories shall be flood proofed. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-13 Revised 2/09 3.19.12 The station shall have a pigging port for pigging the forcemain. Final design to be approved by the City of Centralia Wastewater Department. The station will also have a flow meter which shall be approved by the City. 3.19.13 The entire interior of the wet well and vault shall be coated. The interior coating shall be Ravens Lining. All the exterior joints of the wet well and vault shall be wrapped with WrapidSeal as manufactured by Canusa Protection and Sealing. 3.19.14 All pump stations up to 200 amp service will be 240 volt 3 phase 4 wire. Any above 200 amp will be 480 volt, 3 phase 4 wire. A transformer will be provided for outlets and lighting per standards. In a special case, where 3 phase power is not available, the City will consider a single phase pump station. Security lighting shall be provided for the station. There shall be a minimum of one light. If an overhead power service is used, the lines shall be located so that they do not interfere with the installation or removal of the mechanical equipment at the station. The cables shall be placed such that all work with the crane can meet the set back requirements from the cables. 3.19.15 All electrical equipment shall be enclosed in a free-standing, vandal-proof, all- weather enclosure, NEMA 3R or better. Electrical control panel shall be manufactured by Superior Custom Control, located at 125 27th NE, Seattle, WA 98125, 206-362-8866. 3.19.16 All pump stations shall have an emergency power hookup or an on-site emergency power generator. The City will make the decision regarding which will be required based on the flows and location of the proposed station. All equipment shall be listed, labeled, and approved for the application. 3.19.17 The electrical equipment shall include a 5 KVA minimum transformer for the 120 volt single phase equipment. 3.19.18 Lift station telemetry shall be current with the City of Centralia Telemetry System. If the catalog number changes, you will use the one that is the City Standards at the time of design approval. 3.19.19 Pump motors shall be 3 phase, 240 volt or 480 volt 4 wire as described in 3.19.11. They shall be high efficiency rated. 3.19.20 Wet well sizing criteria: Provide a holding period not to exceed 10 minutes for the design average flow, per DOE’s "Criteria for Sewage Works Design", Section 3.222. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-14 Revised 2/09 Provide for a minimum of 45 seconds pump run time per pump cycle, and a maximum of ten pump cycles per hour. The minimum size of wet well shall be 84-inch diameter. 3.19.21 Lift station emergency storage criteria: Option #1: Emergency storage shall be provided for 2 hours of design average flow, using a peaking factor of 2. This calculation shall be submitted with the system design and must be approved by the City Engineer. Note: The peaking factor was set at 2, rather than 3 or 4, due to the typical emergency being caused by power outage. All volume above area basements and below the hydraulic gradient may be used as emergency storage (wet well, conduit, manholes). This condition must be verified by calculation and submitted for approval by the City Engineer. Option #2: Provide emergency power on site per DOE "Criteria for Sewage Works Design", Section 3.34 3.19.22 The pump electrical controls shall be equipped to automatically alternate the pumps. 3.19.23 All replacement parts shall be available in the U.S.A. Permission in writing from the City shall be required and obtained prior to the review and approval of plans and specifications for the installation of a wastewater lift station. 3.19.24 Alarm and station status points: High wet well Pump 1 run Pump 2 run Pump 1 auto Pump 2 auto Pump 1 fail Pump 2 fail All pumps not auto Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-15 Revised 2/09 The contractor shall supply and install all sensors and auxiliary contacts for the above points and connect them with the appropriate size wire in conduit to terminal strip. The points terminated on the strip shall be identified by number and labeled showing the number and type. 3.19.25 All pump station sites shall be enclosed with a 6-foot chainlink fence with slats. The fence shall conform to the WSDOT Standard Specifications and WSDOT Standard Plan L-2. The slats shall be redwood or an approved equal. Location of fence shall be approved by the City. 3.20 Pressure Sewer (Force Main) General Low pressure systems, i.e., force mains, may be considered for situations where high ground water table or topography make gravity sewer impractical. If a system is approved a tracer wire installation will be required. However, STEP systems are not approved for the City of Centralia wastewater collection system. 3.21 Pressure Sewer Design Standards The design of any sewer extension/connection shall conform to City Standards, DOE's "Criteria for Sewage Works Design", and any applicable standards as set forth herein and in Sections 1.02 and 1.06. The layout of extensions shall provide for the future continuation of the existing system as determined by the City. In addition, main extensions shall be extended to and across the side of the affected property fronting the main. The system shall be designed at full depth of flow on the basis of an average daily per capita flow as shown on the DOE table referenced in Section 3.09. A friction factor of 0.013 shall be used for Manning's "n" value. New sewer systems shall be designed by methods in conjunction with the basis of per capita flow rates. Methods shall include the use of peaking factors for the contributing area, allowances for future commercial and industrial areas, and modification of per capita flow rates based on specific data (I/I). Documentation of the alternative method used shall be provided along with the plans. The applicable General Notes listed following Section 3.09 shall be included on any plans dealing with pressure sanitary sewer design. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-16 Revised 2/09 3.22 Force Main 3.22.1 Material: Force mains for sizes up to 12 inches shall be ductile iron AWWA C151 Class 51 or PVC C900 with ductile iron fittings and gasketed joints. Tracer wire and brass wedge requirements are as in Section 2.03. For 14 to 24-inch mains, pipe shall be ductile iron AWWA C151 Class 51 or PVC C905 with ductile iron fittings and gasketed joints. A more rigid pipe may be required where unlimited trench widths occur. All ductile iron pipe and fittings shall be epoxy coated or PE lined and designed for use with corrosive materials. 3.22.2 Depth: Force mains shall have a minimum 36 inches of cover to top of pipe. See Section 2.13 for sanitary sewer/water main crossings requirements. 3.22.3 Velocity: The minimum velocity allowed is 3 feet per second at average dry weather flow. Three feet per second is required to scour settled solids. Maximum velocity allowed shall be 6 feet per second. 3.23 Pressure Sewer Surge Protection PVC pipe is subject to fatigue failure due to cyclic surge pressures. Lift stations shall be constructed to minimize rapid changes in velocities and a properly sized surge tank and "soft start and stop" pump controls shall be used. 3.24 Pressure Sewer Air/Vacuum Valves Air release valves and air/vacuum valves shall be located at the high points of the line within a standard 48-inch manhole or a comparable sized, approved vault. Air release valves shall be fitted with an activated carbon canister to absorb compounds with disagreeable odors prior to releasing the air to the surrounding area. Grades shall be designed to minimize the need for air/vacuum valves when practical. Vehicular access to valve is required for maintenance. 3.25 Force Main Drain Provisions to drain a force main to facilitate repairs or to temporarily remove force main from service shall be provided. This may be accomplished through the use of a valved tee connected to a drain line at the low point of the line. A manhole shall be set over the force main at the valved tee. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-17 Revised 2/09 3.26 Pressure Sewer Thrust Blocking Location of thrust blocking shall be shown on plans. Thrust block concrete shall be Class B poured against undisturbed earth. A plastic barrier shall be placed between all thrust blocks and fittings. See Standard Drawings 2-10 and 2-18 in the Water Chapter. Designed and approved restraining joint systems may be allowed in lieu of thrust blocking. Restraining joint brand, type and size shall be specified on the plans. 3.27 Force Main Termination Hydrogen sulfide (H2S) odors and the buildup of sulfuric acid (H2SO4) occur in the operation of a force main. To mitigate these conditions, some type of control method(s) shall be used. This may include chemical addition at the pump station and/or the re-aeration of the wastewater at or near the terminus. Re-aeration may include the following: Construction of a vault housing an aspiration assembly. The use of hydraulic fall (vertical siphon) within the terminal manhole. High velocity discharge with smooth transition so as to not cause splashing of force main into the downstream gravity sewer. These methods all require an adequate source of fresh air at the vault or manhole. At a minimum, the manhole at the terminus and the two manholes downstream of the terminus shall be coated with Raven 405 or approved equal which is resistant to sulfuric acid and hydrogen sulfide. The downstream gravity sewer line pipe connecting these manholes shall also be protected from the effects of hydrogen sulfide. 3.28 Pump Station Upgrades The addition of a new pump station or new gravity sewer main extension may cause new flows high enough to make improvements at existing pump stations necessary. Any required upgrades of existing stations shall conform to these standards for a new station. 3.29 Residential Grinder Pumps 3.29.1 A grinder system is a facility consisting of a holding tank, grinder pump and pressure piping system for conveying the wastewater and solids into the sewer system. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-18 Revised 2/09 3.29.2 The City may allow the installation of residential grinder pumps where feasible. The Wastewater Department (Centralia Utilities) will make the final decision regarding the approval of a grinder pump installation. Feasible: 1. Only where a gravity sewer system does not exist and it is physically impossible to accommodate the installation of a gravity main extension. 2. Special circumstances make standard methods unusable. 3.29.3 The grinder pump system shall be designed in accordance with Section C1-10.1 of the DOE’s "Criteria for Sewage Works Design". 3.29.4 The grinder pump shall be manufactured by Environment One Corporation. 3.29.5 The owner shall be responsible for construction of the grinder pump system. Once completed and approved by the City of Centralia, the City will provide all maintenance of the system, ownership of the station will remain with the homeowner. The property owner will reimburse the City for all parts and labor associated with operation and maintenance of their system. The City will not be liable for backups and spill clean-up of backups caused by the systems failure. The developer or homeowner is responsible to supply the City one spare pump core to be placed on the shelf for use in the City’s grinder pump program; this pump will become the property of the City and can and will be used throughout the City’s LPSS system. 3.29.6 The owner shall be responsible for the power bill for the life of the system. An emergency/backup power supply may be required for larger or commercial systems and shall be the responsibility of the customer. 3.29.7 Odor/corrosion control All grinder systems shall be required to mitigate for odors and corrosion. At a minimum, single-family residence installations shall be responsible for the costs of coating three manholes within the cities sanitary sewer system and provide three carbon canister manufactured by SweetStreet. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-19 Revised 2/09 All other systems must be evaluated for the potential to cause odors and corrosion by an engineer licensed within the State of Washington. All calculation used to determine said potential and proposed odor/corrosion mitigation efforts shall be submitted to the City for review. The developer/contractor shall be responsible for all costs accrued during the review process, which may include outside consultation from a licensed engineering firm contracted to the City. If it is found that the minimum requirements or proposed mitigation efforts are insufficient the City will prescribe an acceptable solution. All costs incurred in the development of a City provided solution shall be the responsibility of the developer/contractor. 3.29.8 Commercial grinder systems that have kitchen or cooking facilities, such as churches, community gathering places, restaurants, schools, etc., shall require installation of a grease trap/grease interceptor. 3.29.9 All commercial/industrial installation may be required to install a flow meter at the owner’s expense if deemed necessary by the Wastewater Department (Centralia Utilities). 3.29.10 Grinder System Force Main: A. Mainline/common pressure main. The minimum pipe size used is 2 inches nominal diameter. This is based on maintenance requirements rather than flow. Pipe will be PVC, or SDR 21 (200) with rubber gasket joints. Gaskets will comply with ASTM D 1869. Mains will have a minimum 36 inches of cover to top of pipe. See DOE’s criteria for sewage works design for sanitary sewer/water main crossing requirements. B. Service Line. Service connection pipe will be minimum 1-1/4 inch diameter, Schedule 80 PVC water pipe, solvent weld joint located at 90 degress to the mainline when possible. Solvent cements and primer for joining PVC pipe and fittings will comply with ASTM D2564 and will be used as recommended by the pipe and fitting manufacturers. Service will have a minimum 24 inches cover to top of pipe. The service line shall have two boxes, one within two feet of the station which will house a clean-out, and a lateral connections manufactured by e- one (clean-out box). The second box will house a lateral connections also manufactured by e-one located at the property line (collector box). See Section Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-20 Revised 2/09 2.13 for requirements regarding sewer and water separation. C. Building Sewer. The gravity building sewer between the building and the tank will be designed and installed in accordance with the UPC as adopted by the City. The owner will be responsible for maintenance of the building sewer. D. All pipes will be installed with continuous tracer tape installed 12 to 18 inches under the proposed finished grade. The marker tape will be marked "sewer" and be plastic, non-biodegradable metal core or backing that can be detected by a standard metal detector. Tape will be Terra Tape "D" or approved equal. In addition to tracer tape, install 12-gauge-coated copper wire wrapped around the pipe, brought up and tied off at the valve boxes. A 1-pound magnesium anode will be buried with the sewer line wire splices and connections to anodes will join wires both mechanically and electrically and will employ epoxy resin or heat shrink tape insulation. Furnishing and installing the tracer wire and anodes will be incidental to pipe installation. E. All pipes shall be bedded with sand or suitable material to protect them from backfilling and settling after construction. F. Pressure main’s will be required to have air release valve’s installed at the high points and or at every 2,000 to 2,500 feet along a horizontal run that lacks a clearly defined high point. GRINDER PUMP INSTALLATION The grinder sewer pump shall be an Environment One Model DH071 as supplied by Correct Equipment, Inc., 14576 NE 95th Street, Redmond, WA 98052. Contact Howard Taub at (425) 869-1233. Contact the City for a pre-construction meeting for pump tank and control panel locations before any installation. Contractor shall determine the depth of the existing or future building sewer discharge before any installation, to determine which DH071 will be suitable. The grinder pump lift station package shall include the following items: a) Corrugated HDPE tank with single complete pump unit, ready for installation. The tank will have a 1-1/4 NPT discharge connection and a 4-inch inlet grommet. b) The tank shall include an internal check valve assembly. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-21 Revised 2/09 c) A breaker panel as supplied by Environment One, with two 15 amp breakers for pump operations, one 15 amp breaker for the alarm system, a Push to Run button, an audible alarm with Silence Button, and a red light alarm. All wires and connectors are to be color coded and labeled for ease of installation. d) A minimum of 25-feet of direct bury cable (Supply Cable) between the tank and breaker panel. e) The pump system operates on two pressure switches. One switch operates the pump on/off and the second operates the alarm. f) The package system shall meet the requirements of the L & I, Division for Residential, grinder pump systems. g) The electrical supply to the breaker panel shall be 240-volt single phase-power. Two pole 30 amp breaker, 4 wire circuit required. h) The tank location shall be accessible for maintenance and repair. The tank cover shall be approximately 3 inches above finished grade. Finish grade shall slope away from the station and the station shall not be installed within a "pot hole". No plants, fences, or other obstructions are to be located within 5 feet of the tank and the valve boxes, and the property owner shall maintain a 5-foot clear zone around the tank. i) The location of the breaker panel shall be: • Accessible for maintenance and repair; • In sight of the tank; • The bottom of the Panel must be 5 feet above finished grade; and • The alarm light shall be visible from 50 feet and must be visible in a 180 degree radius. j) The maximum distance between the breaker panel and the grinder tank shall be 25 feet, and with sight and easy access. k) Fences, bushes, or any other object shall not hide the alarm light or hinder in the maintenance and/or repair of the system. l) There shall be no additional junction boxes or splices made once the system has been installed and inspected by City personnel. Anyone tampering with the approved system shall be liable to the City for any expense, loss, damage, cost of inspection or cost of correction incurred by the City, plus a penalty not to exceed $1000.00. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-22 Revised 2/09 CALL FOR INSPECTION Arrangements for inspection of a side sewer installation shall be made with the City, 24-hours in advance. The City reserves the right to set the time for inspection. All inspections will be performed during normal working hours. Cancellations must be made a minimum of one hour before the scheduled appointment. Additional inspection may result in additional fees. (For inspections, phone 360-330-7512) TESTING OR FINAL INSTALLATION – GRINDER PUMP Sewers using pump systems shall be tested at 50 psi, or as directed by the City for actual conditions. The following is the procedure used for testing the discharge line: a) Close the in-line ball valve in the grinder valve box. b) Open the riser ball valve in the grinder valve box. c) Close the ball valve at the collector valve box for the street connection. d) Using hand pump, pressurize with water or air, introduced at the low end, to test for leakage. e) Hold the required pressure for ten minutes. Allowable leakage = 0. AS-BUILT DRAWING As-built drawings shall be prepared by the contractor and checked by the Wastewater Department Inspector (Centralia Utilities) in conjunction with the permit, and shall show the as-built location of all the components of the installations. 3.30 Vehicle and Equipment Washwater Discharge All businesses that regularly wash vehicles and/or equipment surfaces shall conform to the requirements of the Best Management Practices Manual for Vehicle and Equipment Washwater Discharges prepared by the DOE. These requirements will also apply to farm/construction vehicle, equipment rinsing, mobile washers, new/used car dealerships, and charity car washes. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-23 Revised 2/09 3.30.1 Businesses that are specifically a ″Car Wash″, shall be designed for zero (0) discharge to the public sanitary sewer system. Any sanitary sewer connection service such as businesses shall be required to install a flow meter on the discharge line connecting to the City’s sanitary sewer system. Sanitary Sewer Sanitary Sewer Centralia Guidelines 10/08 3-24 Revised 2/09 LIST OF DRAWINGS CHAPTER 3: SANITARY SEWER Drawing Title Number Sanitary Sewer Main Installation General Notes Sanitary Sewer Lateral Service Connection..............................................................................3-01 Type 1 Manhole.........................................................................................................................3-02 Manhole Collar..........................................................................................................................3-03 Cleanout.....................................................................................................................................3-04 Drop Connection (outside manhole)..........................................................................................3-05 Drop Connection (inside manhole)............................................................................................3-06 Typical Grinder Pump Lateral Installation...........................................................................3-07GP Clean-out Box Connection....................................................................................................3-08GP Collector Box Connection ....................................................................................................3-09GP Residential Grinder Pump Lateral (Collector & Clean-out) Box Requirements..................3-10GP Compression Fitting (instructions) ......................................................................................3-11GP Force Main Sewer Lateral Service Connection....................................................................3-12GP Type 1 Low Pressure Clean-out (for non-traffic areas only) ...............................................3-13GP Type 2 Low Pressure Clean-out (with manhole – for traffic areas only) ............................3-14GP Force Main Drop connection system (inside manhole) .......................................................3-15GP