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HomeMy Public PortalAbout2000 - Water Pollution Control Facility Improvements PlanWater Po lution Control Facility Improvements Facility Plan City of Jefferson March 2000 Sverdrup Civil, Inc. St. Louis, Missouri I I I I I I I I I I I I I I I ,J I I I I I CITY OF JEFFERSON WATER POLLUTION CONTROL FACILITY IMPROVEMENTS FACILITY PLAN March 2000 By SVERDRUP CIVIL, INC. St. Louis, Missouri I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS SUMMARY: ......................................•........•....•.•........•.....•.•.•...•......•...•........................................................•............... S-1 SECTION 1 INTRODUCTION •.••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••...•••••...••••..•.•... 1-1 SECTION2 EXISTING CONDITION AND PROJECTIONS .................................................................... 2-1 2.1 STUDY AREA ................................................................................................................................................ 2-l 2.2 STUDY AREA CONDITIONS ................................................ ~ .......................................................................... 2-1 2.3 POPULATION PROJECI10NS ........................................................................................................................... 2-4 2.4 LAND USE AND AREAs OF PROJECTED FuTuRE GROWTH ............................................................................ 2-4 2.4.1 Residential .......................................................................................................................................... 2-4 2.4.2 Commercial and Industrial ................................................................................................................. 2-7 2.5 EXISTING WASTEWATER COLLECTION SYSTEM ........................................................................................... 2-7 2.5.1 Gravity Sewers ................................................................................................................................... 2-7 2.5.2 Sewage Pump Stations ....................................................................................................................... 2-7 2.6 DESIGN ClUTERIA ....................................................................................................................................... 2-13 2.6.1 Average Wastewater Flow Criteria .................................................................................................. 2-13 2.6.2 Peak Hourly Flow Criteria ............................................................................................................... 2-13 2.6.3 Wet Weather Peak Flow Criteria ..................................................................................................... 2-13 2.6.4 Basis for WPCF Design Flow .......................................................................................................... 2-14 SECTION3 EXISTING FACILITIES EVALUATION ................................................................................ 3-1 3.1 EXISTING TREATMENT PLANT SITE .............................................................................................................. 3-1 3.2 EXISTING FACIIJ'I1ES .................................................................................................................................... 3-1 3 .2.1 Influent Pulnpin& ................................................................................................................................ 3-4 3.2.2 Screening and Flow Measurement ..................................................................................................... 3-4 3.2.3 Grit Removal ...................................................................................................................................... 3-5 3.2.4 Primary Clarification .......................................................................................................................... 3-5 3.2.5 Trickling Filttation .............................................................................................................. , .............. 3-6 3.2.6 Final Clarification .............................................................................................................................. 3-6 3.2.7 Final Discharge .................................................................................................................................. 3-6 3.2.8 Plant Water ......................................................................................................................................... 3-7 3.2.9 Sampling ............................................................................................................................................ 3-7 3.2.10 Sludge Thickening ............................................................................................................................. 3-7 3 .2.11 Sludge Storage ................................................................................................................................... 3-7 3.2.12 Sludge Conditioning and Dewatering ................................................................................................ 3-7 3.2.13 Sludge Stabilization and Disposal ...................................................................................................... 3-7 3 .2.14 Odor Control ...................................................................................................................................... 3-7 3.2.15 Buildings ............................................................................................................................................ 3-8 3 .2.16 Electrical Systems .............................................................................................................................. 3-8 3.3 PERFORMANCE AND CAPACITY OF EXISTING PLANT .................................................................................... 3-8 3.3.1 Influent Pump Station and Force Mains ............................................................................................. 3-8 3.3.2 Preliminary and Primary Treatrnent ................................................................................................... 3-8 3.3.3 Secondary Treatment ......................................................................................................................... 3-9 3.3.4 Plant Outfall ....................................................................................................................................... 3-9 3.3.5 Sludge Processing .............................................................................................................................. 3-9 3.4 SUMMARY OF PLANT CONDIDON AND CAPACITY ........................................................................................ 3-9 SECTION 4 EVALUATION AND SELECTION OF IMPROVEMENTS ..... -.... ,_ ..... .-••• -. .................. 4-1 4.1 DESIGN WASTEWATERCHARACTERISTICS ................................................................................................... 4-l 4.2 RECEIVING WATER C0NSIDERATIONS .......................................................................................................... 4-l 4.3 EFFLUENTLIMITATIONS ............................................................................................................................... 4-2 4.4 TREATMENT PLANT SrrE REQUIREMENTS .................................................................................................... 4-2 I I I I I I I I I I I I I I I I I 4.5 ALTERNA11VES ............................................................................................................................................. 4-4 4.5.1 Activated Sludge Options .................................................................................................................. 4-4 4.5.2 Trickling Filtration ............................................................................................................................. 4-6 4 .5 .3 Ballasted Coagulation ........................................................................................................................ 4-6 4 .6 EVALUATION OF ALTERNA11VES .................................................................................................................. 4-7 4.6.1 Alternative No. 1 ................................................................................................................................ 4-8 4 .6.2 Alternative No. 2 .............................................................................................................................. 4-10 4.6.3 Alternative No. 3 .............................................................................................................................. 4-1 2 4.6.4 Alternative No. 4 .............................................................................................................................. 4-1 4 4.6.5 Alternative No. 5 .............................................................................................................................. 4-16 4.6.6 Alternative No. 6 .............................................................................................................................. 4-18 4. 7 SELECTED ALTERNATIVE AND SITE ............................................................................................................ 4-18 4 .7.1 Comparison of Alternatives ............................................................................................................. 4-18 4.7.1.1 Alternative Summary ................................................................................................................................... 4-19 4.7.1.2 Capital Cost .................................................................................................................................................. 4-21 4.7.1.3 Operation & Maintenance Cost .................................................................................................................... 4-21 4.7.1.4 Odor Potential .............................................................................................................................................. 4-21 4.7.1.S River Crossing Redundancy ......................................................................................................................... 4-22 4.7.1.6 TreatmentFlexibility .................................................................................................................................... 4-23 4.7.1.7 Environmental lmplct .................................................................................................................................. 4-23 4.7.1.8 Public Accepe8ncc ........................................................................................................................................ 4-24 4.7.2 Selected Alternative ......................................................................................................................... 4-24 4.7.3 Preliminary Design Selected Plan .................................................................................................... 4-24 4.7.3 .1 Plant Layout ................................................................................................................................................. 4-25 4.7 .3.2 Walnut Street Pump Station ......................................................................................................................... 4-25 4.7 .3.3 Design Plrlmctas ........................................................................................................................................ 4-28 4 .7 .4 Environmental Assessment .............................................................................................................. 4-33 SECTION S PROJECT IMPLEJ\>IENT A TION ......................... -................. -................ -................................. 5-1 5.1 C0STIMPACfSAND FINANCING ...•..•............•.........•...•.•..........................•.................................................... 5-l 5.2 SCHEDULE .................................................................................................................................................... 5-2 I I I I I I I I I I I I I I I . I I I FIGURES FIGURE 2-1 CITY OF JEFFERSON WPCF FACILITY PLAN STUDY AREA ............................................. 2-2 FIGURE 2-2 MISSOURI RIVER INFLUENCE ON AVERAGE DAILY WPCF FLOW ........•....................... 2-5 FIGURE 2-3 MAJOR WATER USERS AND AREAS OF PROJECTED GROWTH ......................••...•.......... 2-8 FIGURE 2-4 EXISTING WASTEWATER COLLECTION SYSTEM ............................................................. 2-9 FIGURE 3-1 EXISTING WASTEWATER TREATMENT FACILITIES ...............................•........................ 3-2 FIGURE 3-2 EXISTING SLUDGE PROCESSING FACILITIES .................................................................... 3-3 FIGURE 4-1 ALTERNATIVE NO. 1 .............................................................................................. , .......•......... 4-9 FIGURE 4-2 ALTERNATIVE N0.2 ..••........•..... .-........•........•.•••...•••••.•••.........•.............•.•.•.•......•...............•..... 4-1 1 FIGURE 4-3 ALTERNATIVE NO.3 .............................................................................................................. 4-13 FIGURE4-4 ALTERNATIVE NO.4 .••.••.•..............••••••.•.••..•..••.•..•...•••.•......••.••.••...•.•..•••..•......••.............••.•.... 4-15 FIGURE 4-5 ALTERNATIVE NO.5 .•...•...••.•..•.•...•....•.............•.....•.•...••..........•...••.............•.•........................ 4-17 FIGURE 4-6 WPCF-60 MGD PEAK FLOW SBR SYSTEM (ALTERNATIVE 5), PRELIMINARY LAYOUT .................................................................................................................................... 4-26 FIGURE 4-7 WALNUT STREET PUMP STATION SITE .•.....•.•......•.•................•.•...................•................... 4-27 FIGURE 4-8 60 MGD PEAK FLOW SBR SYSTEM NEW ADMINISTRATION BUILDING PRELIMINARY LAYOUT ........................................................................................................ 4-3 1 FIGURE 4-9 60 MGD PEAK FLOW SBR SYSTEM MODIFICATIONS TO EXISTING OFFICE AREA PRELIMINARY LAYOUT ........................................................................................................ 4-32 TABLES TABLE2-1 AVERAGE TEMPERATURE AND PRECIPITATION ................•...•.......................•........•........ 2-3 TABLE 2-2 POPULATION PROJECTIONS ................................................................................................... 2-6 TABLE 2-3 CURRENT WASTEWATER COLLECTION SYSTEM ........................................................... 2-1 0 TABLE 2-4 CURRENT SUBMERSffiLE TYPE WASTEWATER PUMP STATIONS .............................. 2-11 TABLE2-5 CURRENT WET WELL/DRY WELL TYPE WASTEWATER PUMP STATIONS ............... 2-12 TABLE2-6 HISTORICAL ANNUAL AVERAGE WASTEWATER FLOW .............................................. 2-15 TABLE2-7 DESIGN AVERAGE FLOW PROJECTION ....•...•...••..........•..•....•...............•......•...•................• 2-16 TABLE 4-1 COMPARISON OF SITE LOCATION OPTIONS ...................................................................... 4-3 TABLE4-2 COMPARISON OF ALTERNATIVES ...................................................................................... 4-20 TABLE 5-1 WCF IMPLEMENTATION SCHEDULE KEY DATES ............................................................. 5-3 I I I I I I I I I I I I I I I I I I I APPENDIX COST BACKUP • Alternative 1 • Alternative 2 • Alternative 3 • Alternative 4 • Alternative 5 I I I I I I I I I I I I I I I I I SUMMARY This Facility Plan summarizes a study of the City of Jefferson Water Pollution Control Facility (WPCF) to identify improvements. that are needed to meet wastewater treatment needs until the year 2020. The planning area tributary to the WPCF includes all of the area within the city limits, portions of Cole County and Callaway County, and approximately one half the wastewater generated by the City of Holts Summit which is treated under contract. Findings: • J>opulation and~ commercial/industrial Jand use will continue to exeanJ! in the planning area . .Population is expected to increase from 51,500 in 2000 to 62,400 in 2020. • During those same years, annual average wastewater flows will increase from 8. 7 mgd to 10.6 mgd. For design purposes, the average annual design flow to the WPCF in 2020 is 11 mgd. The .design flow includes~ approximate 26 percent commercial/industrial flow and 500,000 gal/day from Holts Summit. · 8 For 2020 the design niw wastewate~ BOD, concentration is 210 mg/1 (19,260 lb/day) and the suspended solids concentrations is 235 mg/1 (21,500 lb/day). • -~ to the WPCF ~ignificantly increases during wet weather because of infiltration and inflow J!al: Some of this flow currently overllows at various points in the collection system. The sanitary sewer overflow SSO is rohibited and sholild be eliminated. • An III reduction erogram cari be expected to re uce peak wet weather flow to the WPCF to about 60 mgd. Si nificant · ef ewers will be required to transport the wet weather flow to the WPCF. (Collection system improvements are 1 enti 1ed in a separate Sewer System Master Plan) _ • The Walnut Street Pump Station pumps all of the wastewater collected on the south side of the Missouri River to the WPCF which is on the north side of the river. Significa& improvements to the WPCF and Walnut Street Pump Station are needed to sufficiently handle and treat the 2020 design flows. G The Missouri River is the receiving Stream and is not water quality limited. • The City plans to fund construction of the WPCF improvements using a Missouri Department of Natlll'al Resources (DNR) administered State ..Revolving ]'und ~ WPCF operating costs and debt service on the loan will be funded through user charges. Conclusions: • Replacing the existing WPCF trickling filter treatment system with a Sequencing Batch Reactor (SBR) system best meets the needs of the City. The SBR will treat the low volume dry weather flow and the high volume wet weather flow in the same system. • '[!le existing sludge dewatering system can handle the sludge from the SBR system with minor modification. • Effiuent limits will be a monthly average of 30 mg/1 BODS and 30 mg/1 suspended solids. • The current Walnut Street Pump Station can not be efficiently upgraded to 60 mgd peak flow capacity and should be replaced with a new pump station to be located as close as practicable to the existing location. S-1 I I I I .~ I I I I I I I I I I I I I I • A new 30-inch force main should be constructed under the Missouri River. This in parallel with the existing 30-mch force mam Wi ll convey the 60 mid peak design flow tinder the Missoun ver to the WPCF . The damaged 24-inch force main will be retired from service. • It is most efficient to provide new preli · treatment (screening and grit removal) .UL handle the entire 60 m eak flow . The weather susceptible components should be enclosed to avoid cold weather issues. • The new SBR and prelimin treatment s stem should be constructed west of t existin WPCF facilities. The primary and secondary clarifiers can ecome ponds or fountains and be the focal pomt for a landscaped area. The trickling filters and the current preliminary treatment tanks should be de olished. • The proposed Corps of Engineers flood control levee will block the existing entrance to the WPCF. The entrance should be moved from Mokane Road to the north s1de of the trei tment plant. • A new administration building should be built near the north entrance. It can be located to overlook the landscaped area. The new building should include: • Large conference room for tour group orientation, general meetings, and training programs • WPCF main control room • Laboratory and sampling station • Office for the Plant Superintendent • Office for the Lead Operator • The space vacated from the existing administration should be modified to include: • Large lunchroom • Expanded locker room facilities • Office for the head of maintenance • Small conference room. There would be no modifications to the sludge dewatering facilities and the garage area except the temporary construction in the garage area would be removed. • The budget capital cost of the new facilities should be $22.7 million. • To fund the WPCF improvements user charges should be increased as follows: User Charge Component Current Rate Proposed Rate (Since November I, (Begin July I, 1986) 2001) City Residential User Fixed Monthly Minimum Charge $3.33 $4.16 Outside City Residential User Fixed Monthly Minimum $9.99 $12.47 Volume Charge per 100 cu. ft . $1.055 $1.32 Recommendations: • The modifications listed above to t.'le Water Pollution Control Facility and the Walnut Street Pump Station and force mains should be implemented. • This Facility Plan should be approved by tJ1.e City of Jefferson and then submitted to the Missouri Department of Natural Resources for approval. -- S-2 I I I I I I I I I I I I I I I I I I I • During the Facility Plan approval process, the City should hold a bond election to authorize the bonds to be used for the State Revolving Fund construction financing. • The City should hold a public meeting to e~lain the alternatives that have been evaluated and solicit public comment on the proposed WPCF modifications. A second public meeting is required to explain the impact of the cost of the WPCF improvements on user charges. • ~fter approval of the Facility _ Plan by the DNR, the de~ocuments needed to solicit bids for constrUcting the new facilities ~hould be prepar~. • While the bid documents are being prepared, the City should work with DNR to complete other documents that are required for Revolving Fund loan approval including: • User Charge Ordinance --- • Sewer Use Ordinance • Easements and/or purchase of required property • Engineers Agreement for design, construction and follow-up phase services • The bid documents should be approved by the City and then submitted to DNR for approval along with the construction permit application and associated fee. • Upon approval of all of the above documents and the bond issue, DNR will allow the WPCF improvements to be bid and construction to proceed. S-3 I I I I I I I I I I SECTION 1 INTRODUCTION The .Q.tt..of Jefferson constructed the first treatment system at the current Water Pollution Control Facility (WPCF) site in 1968. Since that time, the plant has been expanded from primary treatment to secondary treatment, and sludge handling taCmties have 6een modified. The most recent construction upgraded the sludge handling and dewatering system and was completed in 1999. The wastewater flow and loading to the WPCF exceeds design capacity in several areas. This Facility Plan is the first step in the process to improve the WPCF to meet current and future wastewater treatment needs. The City anticipates construction financing for the WPCF improvements through the State _].evolving Jund administered by the Missouri Department of Natural Resources (DNR). The process has four steps : • Preparation of the Facility Plan and related clearances, public comment and DNR approval • Preparation and approval of construction documents • Construction • Follow-up to confirm that constructed facilities meet design expectations ~ WPCF Facility Plan summarizes a planning process that culminates in a plan for improvements to the treatment plant to meet wastewater treatment needs for the next 20 years until the year 2020. The Plan describes the current situation with the wastewater system, projects future wastewater loading, investigates alternatives to best treat that wastewater and then recommends the alternative to best meet the needs of the City. The final chapter describes the impact of the WPCF modifications on user charges. ~e Walnut Street Pump Station is part oftb..e Facility Plan. Walnut Street is the influent pump station for the WPCF. The volume of wastewater reaching the WPCF is related to the . condition of the collection (sewer) system that conveys the wastewater to treatment~ Estimates of the current volume of wastewater generated within the City of Jefferson collection area and projected future flows are being developed in another study. That study will develop a Sewer System Master Plan identifying projects to reduce infiltration and inflow .W of extraneous water into the collection system~ also to provide relief sewers for overloaded portions of the system. This Facility Plan is prepared at a time when the United States _§nvironmental...f.rotection Eency (EPA) is moving aggressively toward a policy of eliminating untreated sanitary sewer overflow (SSO). SSOs have always been unacceptable but correcting existing overflows was not a major priority. EPA has been developing background on the issue for years and is now expected to promulgate regulations in the year 2000 that will require communities with SSOs to have a proactive program for elimination., Extraneous wet weather flows will have to be reduced or the collection ·system capacity increased to conve..r all flows that enter the sewers to the treatment plant. l_ Full secondary treatment will be required with possibly some variance during extreme wet condit'ions. Treatment of the flows that exceed the capacity of the secondary treatment system will still be ~ required but possibly to some lower degree of treatment. Missouri regulations currently allow SSO discharge only at the treatment plant and require any flows that must bypass secondary treatment be treated to at least 45 mg/1 BOD and suspended solids. Pending SSO requ~ments were a factor in considering alternative treatment technologies for the WPCF improvements) 1-1 I I I I I I I I I I I I I I I SECTION2 EXISTING CONDITION AND PROJECTIONS 2.1 Study Area The planning area for the City of Jefferson Water Pollution Control Facility (WPCF) comprises all of the City of Jefferson, areas outside the city limits in both Cole County and Callaway County and pumped flow from Holts Summit, Missouri. The study area is approximately 66 square miles and is shown on Figure 2-1. The areas currently served by the WPCF are divided .!!!!o 21 drainage basins. In addition to the current service area, the study area includes some areas not presently served by the ~ity of Jefferson collection syStem and WPCF. These areas outside the service area represen/~~as of potential future developmen9 which are likely to be connected to the existing system ht"the future. The Missouri River divides the study area, with the majority of the area located south of the river and the WPCF located north of the river. The current service area north of the Missouri River, located in Callaway County, includes the area within city limits and a small area north of the city limits. Much of the northern service area J.A __, r was flooded in 1993 and because most of the residential areas were bought out, the area within 'T3'Cf"s the city limits is primarily commercial and light industrial. £low from Holts Summit is pumped Sv?r 177,~ to the North City of Jefferson Sewer Extension near the intersection of Route AC and Highway , 54. The City of Jefferson has an interm~cipal agreement wi~ the City of Holts Summit to provide wastewater treatment capacity fo~OO,OOO gallons per daV The majority of the current service area is located south of the Missouri River in Cole County . The southern service area is general! bordered by the Moreau River to the east and south and by the Grays reek drainage are]. to the west. The Grays Creek drainage area was· originally sewered by the Cole County Regional Sewer District (CCRSD) in the early 1980's. The CCRSD is no longer in operation and responsibility for the collection system in the Grays Creek drainage area is now handled by the City of Jefferson. 2.2 Study Area Conditions The average monthly temperature and precipitation data for City of Jefferson is summarized in Table 2-1. !_he annual average temperature is 53 .6 F and the annual ave e rainfall is 38.43 inches. Typical to Midwest rainf1 patterns, the late spring and early fall months tend to receive the most rainfall. (aecause of the severe topography of the planning area, all of the wastewater flow requires pumping to the WPCF. North of the Missouri River, all wastewater flow reaches the Westinghouse Pump Station and is pumped to the WPCF. South of the Missouri River, all ? ' wastewater flow reaches the Walnut Street Pump Station to be pumped across the river to the LV WPCF. The central portion of the southern service area drains by gravity to the Walnut Street Pump Station. Areas surrounding the centr&_ portion must be pumped once or twice to the central gravity sewer system. The six drainage basins outside the current service area will require pumping to the central gravity sewer system. 2-1 1- ~ a:: LEGEND --STUDY AREA/MAJOR DRAINAGE BAS IN BOUNDAR Y ------CITY LIM ITS ~ (/) (/) 0 c :!!! :!!! ~ ~ ~ ¢-<v '?-CJ r JEFF ER SO CIT Y WPC STATE CAP ITOL FIGUR E 2-1 CITY OF JEFFE RSON WPCF FACILITY PLAN STUD Y AREA I I I I I I I I I I I I I I I I I I TABLEl-1 AVERAGE TEMPERATURE AND PRECIPITATION Month Mean Precipitation Temperature Mean January 27.4 1.38 February 31.6 1.73 March 42.7 3.28 April 54.2 3.55 May 63.4 4.94 June 72.0 4.41 July 77.4 3.04 August 75 .4 3.14 September 67.4 3 .97 October 55 .8 3.49 November 43 .6 2.88 December 31.9 2.62 Annual 53.6 38.43 Data provided by Midwestern Climate Center Averages: 1961-1990 Extremes: 1890-1996 2-3 High-Year 7 .82 1897 6 .20 1892 11.51 1922 13.89 1922 11.02 1892 10.18 1969 13.38 1993 12.37 1946 12.83 1993 14.12 1941 9 .86 1992 9 .20 1895 66.13 1993 I I I I I I I I I I I The Missouri River divides the study area and can have an impact on the wastewater flows to the WPCF . Fig_ure 2-2 shows the average daily flows for various daily precipitation amounts at river stage 1 i through 30. This graph .illustrates that average daily flows to the WPCF tend to increase as river stage increases . The City is curreirtiy conducting a program to identify and correct sources of river infiltration and inflow. 2.3 Population Projections The Year 2000 is the baseline condition and the Year 2020 is the future design basis for this study . Population projections for the 20-year design period are summarized in Table 2-2. Populations for the Year 1990 are based on census data. Growth in City of Jefferson is based on a projected increase of 4.7% per decade, the average growth over the past 20 years . The decrease in population between the Year 2000 and the Year 2010 is due to the expected closing of the Missouri State Prison within the next 5 years . Population projections for service areas in Cole and Callaway County are developed from the Comprehensive Plan Update prepared for City of Jefferson1• Growth in the service area located in Cole Count.y conservatively assumes a high projection increase of 10% per decade, slightly higher than the low and moderate projections in the Comprehensive Plan Update. In addition, growth projections in the Cole County service area assume 73% of the Cole County population will locate within the Ci.!}' of Jefferson service area, similar to the results of the 1990 census data. Growth in the service area located in Callaway Countt is based on a high projection increase of 20% per decade and does not include Holts Summit. According to census data, the population of Holts Summit decreased between the years 1980 and 1990, while the population of Callaway County increased as a whole. Population projections for Holts Summit are beyond the scope of this plan. Therefore, the existing and future wastewater flows from Holts Summit are to be based on past billing records and the maximum wastewater treatment capacity allowed in their intennunicipal agreement with City of Jefferson. 2.4 Land Use and Areas of Projected Future Growth The City of Jefferson WPCF serves approximately _18,000 acres (about 28 square miles) within the city limits and approximately 24,000 acres (about 38 square miles) outside the city limits. Currently, just over half of the area within the city limits is developed . 2.4.1 Residential Developed land usage in City of Jefferson is predominately residential. Distribution of the baseline (Year 2000) residential population in the current WPCF service area is based on the 1990 census tracts and development that has occurred over the past 1 0 years . Discussions with city planning personnel indicate that residential growth within the city limits in the past 1 0 years has focused in the west and south central ortions of the City, as well as continued development WI n existing residential areas. Future growth is expected to be similar to the past 10 years . 1 "Comprehensive Plan Update, C ity of Jefferson, Missouri", prepared by Landfonn Urban Planning Services, St. Lo uis, Missouri, March 1996. 2-4 --------- FIGURE 2-2 MISSOURI RIVER INFLUENCE ON AVERAGE DAILY WPCF FLOW (January 1997 through December 1998) -- 9.5~--------------------------------------------------~ 9 .-.. = I 1--+-RS < 11' ~ ~s ::g I-RS <1 2' '-' 8.5 - ~ ,/ I I-A-RS < 13' Q $.0 -1 1-w-RS < 14' ~ -• ~ 8 = I ~ iS"" I I--Rs < 15' ~ = I ~ -______. • ~ == .. P4 13 T 1-+-RS < 20' ~ .. t)l) 7.5 I 1-+-RS < 25' ~ a. ,a_ ~ > • • • T I -RS <30' < • • • • • I l 7 6.5+-------~--------r-------~--------r-------~------~ 0 0 .5 1 1.5 2 2.5 3 Precipitation -Less Than or Equal To (inches) I I I I I I I I I I I TABLE2-2 POPULATION PROJECTIONS . ' YEAR SERVICE AREA 1990 (Actual) · 2000 Jefferson City/South of Missouri River 35,175 36,800 Jefferson City/North of Missouri River and 319 400 Service Area in Callaway County Service Area in Cole County 11,122 14,300 (outside of city limits) TOTAL SERVICE AREA POPULATION 46,616 51,500 Notes: 1. Jefferson City population projections based on a 4.7% increase per decade. 2010 36,400 500 19,800 56,700 2. Jefferson City Year 2010 population projection includes loss of Missouri State Prison. 3. Jefferson City/North of Missouri River and Service Area in Callaway County population projections based on a 20% increase per decade. 2020 38,000 600 23,800 62,400 4. Service Area in Cole County (outside city limits) population projections based on a 10% overall increase per decade in Cole County, and asswnes 73% of Cole County population resides in Jefferson City service area. 2-6 I I I I I I I I I I Q!Qwth Qutside the city limits has been primari_!y west of the City !!! the Grays Creek drainage ~Based on review of the Annexation Plan for the City of Jefferson, Missoure, growth areas outside the city limits are. expected to focus in the areas southwest and west of the city limits. Areas of expected residential growth are shown m Figure 2-3. 2.4.2 Commercial and Industrial Existing (Year 2000) commercially developed land within City 2f Jefferson is res. Existin indus · velopment is also 600 acres. In addition, the followin major industrial and commercial water user are shown on Figure 2-3 . Missouri State Penitentiary (Year 2000 only) ABB Power T & D Co. Modine Manufacturing Company Unilever/Chesebrough Ponds Mo State Capital and Harry S . Truman State Office Builiing St. Mary's Health Center Von Hoffinann Press, Inc. Commercial growth in the City 1!_ based on a projected increase of 24 acres per year, the average growth from 1977 to 1992. Future commerclalare"as are assumed to be located in undeveloped land within the city limits zoned for commercial use and in outlying areas of St. Martins, along Business 50 West and along Frog Hollow Road. Industrial owth is projected to be approximately 12 acres r ear slightly less than the growth from 1977 to . uture m ustri areas are assumed to be located in undeveloped land within the city limits zoned for industrial use. Industrial growth is difficult to predict and is affected by available industrial park settings, severe topography south of the Missouri River and areas north of the Missouri River located in the 100-year floodplain. 2.5 Existing Wastewater Collection System 2.5.1 Gravity Sewers The gravity sewer system for the City of Jefferson service area is shown in Figure 2-4. The current service area has been divided into 21 drainage basins. Table 2-3 summarizes the size and major sewer length for each drainage basin. There are over 1.2 million feet (233 miles) of major gravity sewer in the current service area, ranging in siZe from 8-inch up to 48-inch in diameter. "'\ 2.5.2 Sewage Pump Stations As discussed previously, because of the topography of the City of Jefferson study area,~ wastewater collection ~stem includes exte~vepumping_. There are currently 29 sewage .P...umping stations. Fifteen stations ~ the submersible type. Submersible pump station capacities, pump information and year of construction are summarized in Table 2-4. Fourteen stations are the wet welVdry \Ven type. Wet welVdry well pump station capacities, pump information and year o f construction are summarized in Table 2-5 . 2 "City of Jefferson Annexation Plan, 1996", by D.R. Preston, December 1996. 2-7 I [ r ..--...-., I \ \ \ . ~-\ I .... ' ( \ ST. MAR TINS --.... ' l EL ST ON ______ , I \ t I / I----1 .... ___/ .... "-........ \ ' ~ f', \ fJ? I ' 8 I ',__ -_.:u q'_,. I ', v-f I ',, ~ f ----\/ .... , HWY 54 I ' ~ I -.. \__ I Ol ',, / • ' .... \ 2... ABB I ,....._ ''---I ' \ I \ ' I I=! \ I ' / I a::: ',, (/ Rrt 94 • ~ __ r J ' ', 1 ', ~--: \--------' • llvous ' ... ,,, 1 ) / r JEFF ERSONI I ---~ _} "?1-4( '-..1 CITY WPC F I I CH ESEB ROUGH • J. 0-?. ;-I ___ l PONDS / ST ATE I (J HwY so -• r CAPI TOL I l'1 VON HOFFMANN j I ~---·------, . • I MISSO URI STATE PENITENT IARY I ~ PR ESS j . I I ST. MA R.Y'S .• l \_ . I .,-' \ I . • I.... / ,.-----MODINE MFG "l I HEAL TH CENTER ' -'-..,, [ __ ....... ~-------~-----~~~· ____ j -L I TRUM AN STATE ................ , __ _ I I --9 I "/· .}'>. J OFFICE SLOG . ----1__ (~---.J r-.v 1 -. --, v --~....., 1 ,t(. / G • Ol 1 cc-4 1r--_ L ___ j <t..Q;;- 0 ~· ! ~· Rrr sr : __...--\ 0:: I II / I N .... _____ "" '' ) \ u.J I I 0:: I I ~ I I HWY c ~ I Hwy so/BJ 1 l , / LEGEND -··-STUDY AREA BOUNDARY ------CITY LIMI TS • MAJOR WAT ER US ER AREAS OF PROJECTED D GRO WTH OUTS ID E CITY LIM ITS ---- I \ , ( \ \ u u I II ----_,.""" I r ---------,------=~~ -----_/_,.,. I_ I / , ---~---~----, ~L--' 1 / ', r \ l --~--..... ,\ '\ \ --'' ~ ', -----....._ I \ ' \ ( '' _j_,.._ ______ ,~\ \....... j ___ ..,.. ( \ \ \ ' / ... _ ... ' FIGURE 2 -3 MAJOR WAT ER USERS AND AR EAS OF PROJECTED GROWTH ' I / \ J r r LEGEND 3 • WEST'v1EW N STUDY AREA /MAJOR DRAINAGE BASIN BOUNDAR Y PUMP STATION SEWER SYSTEM 21A RAN DALL • HW Y 5o ~ 8 ?d ?d ~ .. \_ ~ I FIGURE 2-4 EX IST ING WASTE WATER CO LL EC TI ON SYS TEM I I I I I I ' I I I I I I I I I I I TABLE2-3 CURRENT WASTEWATER COLLECTION SYSTEM Drainage Basin No. Area (acres) Estimated Length of Major Sewers (ft) North of Missouri River 1 222 20,700 2 1,817 12,300 Subtotal 2,039 33,000 South of Missouri River 3 1,078 45,800 4 375 31,800 5 816 59,600 6 592 51,900 7 435 68,700 8 302 21,800 9 864 72,100 10 4,910 85,300 11 1,264 132,600 12 856 93,500 13 1,601 88,500 14 403 31,300 15 393 22,000 16 1,749 110,100 17 936 67,400 18 347 29,300 19 127 15,600 20 3,483 50,000 21 11,747 120,000 Subtotal 32,278 1,197,300 Proposed Future Service Area A 581 Unknown B 1,447 Unknown c 1,011 Unknown D 1,647 Unknown E 750 Unknown F 2,067 Unknown Subtotal 7,503 TOTAL 41,820 1,230,300 2-10 I I I I I I -I I i I I I I I I I I Pump Station Name Covington Southridge Cedar City Dover Randall Sylvan Hills Gun Club Woodward Bonita Paseo Windriver Haaf Iven Westport Scholastic Command Web Notes: TABLE2-4 CURRENT SUBMERSIBLE TYPE WASTEWATER PUMP STATIONS Drainage !Pump Pump No. of Type of Station Basin Capacity Motor Pumps (gpm) (hp) 10 800 90 2 Submersible 9 300 ·22.5 2 Submersible 1 260 7.5 2 Submersible 13 200 23 2 Submersible 21 100 7.5 2 Submersible 15 50 7.5 2 Submersible grinder 21 50 5 2 Submersible grinder 21 30 3 2 Submersible grinder 21 Unknown"' (2) 1 Submersible pump 16 50 5 2 Submersible grinder 16 Unknown 5 2 Submersible grinder 3 Unknown 2 1 Submersible grinder 10 Unknown j 3 1 Submersible grinder 16 50 5 2 Submersible grinder out 1 Unknown 3.5 2 Submersible grinder 1. Command Web pump station is east of Moreau River and is outside the study area. 2. Bonita Paseo Pump Station serves a single basement. 3. Westport Pump Station serves approximately 5 houses. 2-11 Year Constructed 1998 1980 1990 Unknown 1991 1983 Unknown Pumps replaced 1990 1994 1988 Unknown 1987 1995 1992 1994 I I I I I ' I I I I I I I I I I I I Pump Station Name Walnut Street Cole Junction Binder Riverside Park Westview Moreau (Greenberry) Westinghouse Idlewood Hayselton Green Meadow St. Martins #2 (South) St. Martins #1 (North) T-Road Indian Hills Notes: TABLE2-S CillUmNT~T~LLIDRY~LLnTE WASTEWATER PUMP STATIONS Drainage !Pump Pump No. of Type of Station Basin Capacity Motor Pumps (gpm) (hp) 19 12500 400 2 Wet well/Dry well 5600 100 1 21 1925 150 3 Wet well/Dry well 20 1700 100 2 Concrete wet well with buried metal dry well 17 1500 50 2 Wet well/Dry well 10 950 60 2 Concrete wet well with buried metal dry well 4 800 100 2 Wet well/Dry well 1 700 10 2 Concrete wet well with buried metal dry well 8 350 60 2 Concrete wet well with buried metal dry well 15 300 20 2 Wet well/Dry well 3 300 . 14.6 2 Concrete wet well with buried metal dry well 21 150 10 41 Wet well/Dry well 21 140 15 2 Wet well/Dry well 21 25 3 1 Wet well/Dry well 16 100 20 2 Wet well/Dry well Year Constructed 1968 1982.1. 1983 1966 1987 1965 .. 1971 1983 1956 ~ 1969 ° 1994 1994 Unknown 1979 1. St. Martins #2 (South) Pump Station includes two duplex pump stations piped with pumps in series (4 pumps total). 2. Cole Junction Pump Station: one pump is new, another was rebuilt, all have original motors. 3. Riverside Park Pump Station: pumps have been rebuilt, but have original motors. 4. Moreau Pump Station: new pumps with soft starters installed in 1994. 5. Hayselton Pump Station: pumps replaced in 1983. 6. Green Meadow Pump Station: pumps replaced in 1996. 2-12 I I I I I I I I I I I I 2.6 Design Criteria 2.6.1 Average Wastewater Flow Criteria Wastewater flow rates are developed for several types of land uses including residential, commercial/light industrial, and major users. The average flow criteria for these sources are: Residential: 100 gallons per capita per day (gpcd) Commercial/Lt Industrial:1,000 allons er acre erda (gpad) 'ajar Water Users:Based on water usage records The residential wastewater contribution of 100 gpcd is based on MoDNR recommended criteria for sewer design and includes some allowance for infiltration. Typical values in literature for estimation of peak flows from commercial and light industrial sources range from 3,600 gpad to 5,000 gpad. Because major water users are taken into account separately, an average flow of 1,000 gpad, with an 8-hour per day operation, is used for this study, resulting in a peak flow rate of3,000 gpad. For the purposes of this study, major water users are defined as facilities that average over 50,000 gallons per day water usage. Based on water usage information provided by the City, major water usage is summarized in Table 2-7. Additional allowance is included in the design average flows to account for wet weather and Missouri River influences. The additional average flow component is based on the historical average flows to the WPCF. 2.6.2 Peak Hourly Flow Criteria Peak hourly flow criteria is based on the Missouri DNR peaking factor criteria: 18 + (Population in thousands t"5 4 +(Population in thousands)0·5 2.6.3 Wet Weather Peak Flow Criteria Development of wet weather peak flows is based on the recent hydraulic modeling of the collection system at selected design storms. Calibration of the hydraulic model developed for the wastewater collection system was based on the results of a spring 1999 flow monitoring program that is part of the Sewer Master Plan Project. The flow-monitoring program was conducted from March 21 through May 31, 1999 at 20 locations throughout City of Jefferson. Precipitation was normal for this period. Major contributors to wet weather peak flows are rapid infiltration and inflow. Rapid infiltration is defined as rainfall dependant infiltration that enters the collection system below ground. Typical sources of rapid infiltration include defective pipe joints, cracked pipe, or faulty manholes. Inflow is unwanted surface water that enters the collection system during storm events. Typical sources of inflow include submerged (or missing) manhole covers, roof drain connections, broken pipe in creek crossings or improper connections to storm sewers. Sources of 2-13 I I I I I ' I I I I I I I I I I I I inflow and infiltration can also be located on private property, such as roof drain or foundation drain connections, and in private sewer laterals. Infiltration and inflow are extremely variable and to a large extent depend on the intensity and duration of a storm event. Wet weather peak flows for existing conditions were used as the basis for calibrating the hydraulic model infiltration and inflow components. Wet weather peak flows for future conditions are based on design storms with 10-year and 5-year frequency. The design storm for evaluating the collection system hydraulics is the 10-year, 6-hour storm. The 1 0-year, 6-hour design storm is an intense storm, which generally occurs over a small area. Because of the size of the City of Jefferson service area, peak wet weather flows to the WPCF and to Walnut Street Pump Station are based on the 5-year, 6-hour storm. Characteristics of these two design storms are: Return Period: 10 years5 years Duration: 6 hours6 hours Total Volume:3.6 inches3.1 inches 2.6.4 Basis for WPCF Design Flow The historical annual average wastewater flows to the City of Jefferson WPCF are summarized in Table 2-6. Fluctuations in the average annual wastewater flow can be attributed to the impacts of wet weather and Missouri River stage on influent flows. The estimated existing (Year 2000) annual average flow is 8. 7 million gallons per day (mgd), the average of years 1997, 1998 and 1999. The design (Year 2020) average flow is 11 mgd. Development of the design average flow is summarized in Table 2-7. The design average flow includes an allowance of 1.5 mgd for wet weather conditions and river influence. The allowance is derived from the difference between the estimated actual 2000 flow of 8. 7 mgd and the calculated 2000 flow of 7.2 mgd. Based on the MoDNR peaking factor formula and a Year 2020 population projection of 62,400, the design peak dry weather hourly flow is 25 mgd. The peak hourly flow is based on the design average flow of 11 mgd and a peaking factor of2.2. The design wet weather peak flow to the WPCF is a combination of flow from the service area north of the Missouri River and the service area south of the river. The majority of the City of Jefferson service area is located south of the Missouri River, where the flow drains to Walnut Street Pump Station to be pumped to the WPCF. The 1999 flow-monitoring program indicated significant infiltration and inflow in all of the drainage basins in the south service area. Hydraulic modeling using the 5-year, 6-hour design storm basis estimates a wet weather peak of 86mgd. Evaluation of wet weather flow reduction indicates it will be cost effective to develop and maintain a program of infiltration and inflow (III) reduction throughout the majority of the collection system. Based on the hydraulic modeling for the 5-year, 6-hour design storm, reducing inflow in a majority of the drainage basins can decrease the wet weather peak to 63 mgd. The wet weather peak flow can be reduced to 58 mgd by also addressing infiltration in six major drainage basins. The recommended infiltration and inflow reduction program also includes addressing sewers which may be impacted by the Missouri River. 2-14 I I I I I I I I I I I I I I I I I I I I TABLE2-6 HISTORICAL ANNUAL AVERAGE WASTEWATER FLOW Year Jefferson City Annual Annual Above or Below Population Averafe Precipitation Annual Average4 (mgd) (inlyr) 1980 33,619 4.6 26.7 Below 1981 5.8 45.9 Above 1982 6.5 52.4 Above 1983 6.3 37.5 Below 1984 8.2 33.1"' Unknown 1985 9.6 53.1 Above 1986 6.6 39.5 Above 1987 6.2 33.1 Below 1988 6.4 36.2 Below 1989 6.1 31.9 Below 1990 35,494 7.1 52.1 Above 1991 6.6 35.6 Below 1992 7.2 38.9 Above 1993 7.6 1 66.1 Above 1994 7.4 33.3 Below 1995 7.2 37.9 Below 1996 7.2~ 38.0 Below 1997 8.2 36.3 Below 1998 9.3 61.6 Above 1999 (Estimated) 8.5 na na 2000 (Estimated) 37,200 8.7 na na Notes: 1. Plant was shut down in 1993 for several months 2. Based on WPCF Operating Data, with some missing data in September, October, and December 3. Missing September data 4. Average annual precipitation= 38.43 in/year (1961-1990) 5. Walnut Street Pump Station was limited in pumping due to the hydraulic capacity of the head works. 2-15 I I I I I I I I I I I I I I 11 I I I I I TABLE2-7 DESIGN AVERAGE FLOW PROJECTION Year 2000 Type of Flow and Design Criteria Design Average Flow Basis (mgd) Residential: Study Area Population 51,500 less MO State Prison 2,000 Estimated Population 49,500 Residential A vg Flow (at 100 gpcd) 5.0 Major Water Users (gallons per day): MO State Prison 400,000 ABB 55,000 ModineMfg. 95,000 Unilever/Chese. 70,000 MO State Capitol 40,000 Harry S. Truman State 68,000 St. Mary's Med. Cen. 62,000 Van Hoffmann Press 50,000 Major Water Users Avg. Flow 840,000 0.8 Commercial & Light Industry Max. Flow (gallons per acre per day, gpad) = 3,000 Assume 8 hour oper., average flow (gpad) = 1,000 Commercial Area (acre) 600 Light Industry Area (acre) 600 Comm. & Lt. Industrial A vg. Flow 1,200 1.2 Holts Summit 0.2 Total Average Flow 7.2 Year 2000 Estimated Average Flow (based on historical 8.7 annual average flows) Additional flow (MO River influence, precipitation) 1.5 DESIGN YEAR 2020 AVERAGE FLOW 2-16 Year 2020 Design Average Flow Basis (mgd) 62,400 6.2 0 55,000 95,000 70,000 40,000 68,000 62,000 50,000 440,000 0.4 1,100 850 1,950 2.0 0.5 9.1 1.5 11 I I I I I I I I I I I I I I I I I I I The Year 2020 estimated wet weather peak flow for the area south the Missouri River of 58 mgd is based on the following assumptions: • Design storm is 5 year, 6 hour storm event • Inflow will increase 0.5% per year • Infiltration will increase 2% per year • III reduction in selected basins The service area north of the Missouri River is small. Because of limited development in the area, no flow monitoring was conducted. The pump station serving Holts Summit discharges to the upper end of the service area. The Year 2020 design wet weather peak flow of 2 mgd is based on the following assumptions: • Peak factor of 4 on residential flows • Peak factor of 3 on commercial and industrial flows • Infiltration allowance of 30,000 gallons per day per mile of trunk. sewer • Holts Summit pump station has both pumps in operation and assuming maximum capacity is 1.5 times one-pump capacity Based on the study results, the peak wet weather flow to the WPCF from both the north and south service areas would be approximately 60 mgd, for the 5-year, 6-hour design storm. Therefore, 60 mgd is used as the peak wet weather design flow for the WPCF. 2-17 I I I I I I I I I I I I I I I I I I SECTION3 EXISTING FACILITIES EVALUATION 3.1 Existing Treatment Plant Site The existing Jefferson City Water Pollution Control Facility (WPCF) is located on a 22.42 acre plot on Mokane Road, approximately 0.4 miles north of the Missouri River, directly opposite the State Capitol Building. The property surrounding the facility is largely vacant, being in the unprotected Missouri River flood plain; several light industrial facilities are situated within about 2,000 to 2,500 feet of the plant. No water supply structures are located near the plant. Expansion of the Water Pollution Control Facility is possible to the east and to the west of the existing facility. Expansion to the north is limited by the presence of the Jefferson City Memorial Airport. The terrain is flat, though the land east of the plant was used as a borrow area during the original plant construction. Vegetation in the area of the plant is sparse. The existing plant site is located within the 1 00-year flood plain. During the flood of 1993 (a 500-year event), the Water Pollution Control Facility was inundated and suffered significant flood-related damage. Treatment was suspended for four months. During the 1995 flood (a 10- year event), treatment was suspended for approximately one month. The U.S. Army Corps of Engineers is planning to construct a levee to protect the airport, treatment plant, and other land owners to a river stage of 43.9 (approximately a 1 ,000-year event). The presence of this levee will likely result in an increase in flood plain development adjacent to the treatment plant. 3.2 Existing Facilities The existing Jefferson City Water Pollution Control Facility is a secondary treatm~nt facility, discharging to the Missouri River at River Mile 143.3, under NPDES Permit Number M0- 0094846. Current (1999) wastewater flows and characteristics are summarized below: Average Daily Flow Peak Hourly Flow Average Influent BODs Average Influent TSS 8.5 mgd 18mgd 200 mg/1 235 mg/1 Current NPDES permit discharge limits are 45 mg/1 for BODs and TSS on a monthly average, and 65 mg/1 on a weekly average. Figures 3-1 and 3-2 present schematics of the current wastewater and sludge treatment processes. The plant was originally constructed in the late 1960s as a primary treatment facility, consisting of an influent pump station and force mains across the Missouri River, a headworks that included a Parshall flume and comminutors, two aerated grit tanks and a grit classifier/cyclone, two primary clarifiers, and an effluent pump station. Sludge was processed through a gravity thickener, centrifuges, and an incinerator. 3-1 -------______ .. ____ _ 1---+-PLANT WATER HIGH WATER PUMP STATION GRIT REMOVAL AND PRIMARY CLARIFIERS I I PREAERATION FINE SCREEN AND PARSHALL FLUME I -------------------------. : SETll.ED SEWAGE : PUMP STATION UNDERFLOW AND FILTRATE FROM TRICKLING FILTERS SLUDGE PROCESSING ------------------+------ I I I I I I I I I I MISSOURI RIVER WALNUT PUMP STATION :.-------RECYCLE LINE ------------------------------- FIGURE 3-1 EXISTING WASTEWATER TREATMENT FACILITIES SECONDARY CLARIFIERS ------------------- PRIMARY AND SECONDARY SLUDGE FERROUS CHLORIDE GRAVITY SLUDGE THICKENERS I I I I I I ......... : -~ FERROUS CHLORIDE THICKENED SLUDGE STORAGE POLYMER HYDROGEN PEROXIDE BELT FILTER PRESSES I I I I I I I I I I I I I I I I !"'------------------------------------------------------------------------' I I I I I I I I ' UNDERFLOW AND FILTRATE TO WASTEWATER TREATMENT FIGURE 3-2 EXISTING SLUDGE PROCESSING FACILITIES LIME L. ['ol TOLAND DISPOSAL I I I I I I I I I I I I I I I I I I In the late 1970s, two additional primary clarifiers were added, along with secondary treatment facilities consisting of a settled sewage pump station, two trickling filters, two final clarifiers, and effluent chlorination. Vacuum filters were added for sludge dewatering and the centrifuges were abandoned. In the mid-1980s, the comminutors were replaced by a mechanically-cleaned climber screen upstream of the Parshall flume, chlorination was abandoned, and the sludge incinerator was taken out of service. In 1998 and 1999, a continuous mechanical fme screen replaced the climber screen, the grit classifier was replaced, structural repairs were made to the aging trickling filter towers, and sludge handling operations were significantly upgraded. A second gravity thickener was added, a thickened sludge storage tank was constructed, and the vacuum filters were replaced with two belt filter presses. Various ancillary systems were built or expanded, including polymer feed systems, sludge pumping, sludge conveyors and lime addition. The paragraphs below describe the facilities and their condition as they exist in 1999. 3.2.1 Influent Pumping The influent wastewater pump station is located on the south side of the river at Walnut Street and West Main. The pumping system consists of a diversion/bypass structure where the two main trunk sewers serving the project area south of the Missouri River are combined, the pump station, and force mains that convey the wastewater to the treatment plant on the north side of the river. The pump station contains two 18 mgd pumps and one 8 mgd pump. The original force main system consisted of parallel 24-inch diameter mains laid across the river bottom. One 24- inch main was destroyed during the flood of 1993 and the other suffered significant damage, requiring the installation of a new 30-inch diameter horizontal directionally drilled force main under the river bed in 1995. - Although the pump station is in fair condition structurally, mechanical and electrical equipment within the pump station is in very poor condition. Pumping tests performed in March 1999 confirmed that the pumps are not operating at their original design specifications. The new 30-inch river crossing force main is in good condition. The 24-inch force main still in service is in very poor condition. 3.2.2 Screening and Flow Measurement All wastewater entering the treatment plant is screened through a new Parkson Aquaguard® continuous fme screen with 6-mm openings. Movement of the screen can be continuous, or can be controlled by level sensors mounted in the flow channel. Flow in excess of the fme screen capacity (25 mgd) passes through a coarse bar rack with 3/4-inch openings between the bars. The screened flow passes through a 4-ft Parshall flume, providing flow measurement up to 34 mgd. The screening equipment is in very good condition, but is prone to freezing in cold weather; a temporary enclosure and heater have been constructed. The influent structure is in fair condition. 3-4 I I I I I I I I I I I I I I I I I I 3.2.3 Grit Removal Screened wastewater enters two aerated grit basins. Each basin has dimensions of 45-ft long by 12-ft wide, with a volume of 48,000 gallons, and can be isolated by use of slide gates. Weirs at the discharge end maintain the flow depth in the basins. Aeration is provided by coarse bubble diffusers supplied with air by two rotary-lobe positive displacement blowers, each rated for 344 cfm. One blower is normally operated to serve both grit basins. The grit basins are covered and odorous air is collected for treatment. Settled grit is collected by a screw at the bottom of each basin, designed to move 16 cubic feet of material per hour when rotating at 2.2 rpm. The collected grit is then pumped by two recessed impeller centrifugal pumps rated for 250 gpm at 37-ft TDH to a grit classifier/cyclone and dumpster. The collector screws and grit pumps are operated on a timer basis. The concrete grit basins have experienced moderate corrosion above the water line due to hydrogen sulfide emissions. Manual slide gates used to isolate tanks are difficult to operate. The aeration blowers are in fair condition considering their outdoor location. The grit screws/drives provide continual problems to the plant and require much maintenance. The grit pumps are in good condition. The grit classifier/cyclone is in excellent condition, although the building housing it is too small and has no ventilation. 3.2.4 Primary Clarification Following grit removal, the wastewater enters a splitter box for division to the four primary clarifiers. The splitter box contains a skimming device for removal of accumulated scum. Each clarifier is a 60-ft diameter center-feed unit with a side water depth of 9 feet. Iron salts are sometimes added to the flow following grit removal to control odors and enhance the performance of the primary clarifiers. Polymer can also be added at the splitter box. Sludge from each clarifier is collected by a scraper mechanism and pumped by a dedicated air-operated diaphragm pump to the sludge thickeners. Each pump has a 164 gpm maximum capacity when working at 40 strokes per minute, and is operated on a timer basis, alternating between the four pumps. Currently, the pumps are run at about 9 strokes per minute, or 3 7 gpm. Air for the pumps is provided by a dual reciprocating compressor rated for 52 cfm at 1 00 psig. The compressed air is cooled and dried prior to use in the pumps. Skimmings are pumped back to the headworks by a diaphragm pump identical to the sludge pumps. A 500 gpm (24-ft TDH) centrifugal drain pump is provided for dewatering the clarifiers. The splitter box and slide gates are in fair condition although the scum removal system in the splitter box is inoperable. It has been noticed that the flow to the four clarifiers is not distributed evenly, and that under high flow conditions, the box can overflow. The primary clarifiers are in good shape structurally, but the groundwater relief system gates are inoperable. The clarifier drives were rebuilt after the flood of 1993 and appear to be in good condition. The scum troughs and rakes on the two older units (Nos. 1 and 4) are undersized, and the entire scum disposal system poses operating problems. Sludge withdrawal from the two newer clarifiers is difficult due to their distance from the sludge pumps. The sludge pumps, scum pump, and air delivery system (compressors, cooler, dryer) are all in fair condition but require frequent maintenance. 3-5 I I I I I I I I I I I I I I I I I I The clarifier drain pump is undersized, requiring 8 hours to drain a tank, and its location makes maintenance difficult. 3.2.5 Trickling Filtration Settled sewage, together with recycled filter effluent, is pumped to the trickling filter towers by four vertical turbine pumps. Two of the pumps are driven by constant speed motors and are rated for 4,000 gpm at 46-ft IDH. The other two pumps are driven by motors controlled by variable speed drives. These two pumps are rated for a maximum flow of 4,600 gpm at 46-ft IDH. Normally, both variable speed pumps and one constant speed pump are operated; the constant speed pumps are alternated. A minimum wet well level is maintained to prevent vortexing. The pumped flow passes through magnetic flow meters and then to the two trickling filter towers. Each tower is 65-ft diameter and contains 21 ~ feet of PVC corrugated-sheet, vertical flow media. Flow distribution is by four-arm reaction-type rotary distributors. The distributors currently were observed to operate at a St of about 5 to 10 mm/pass. Ventilation is natural, and can be controlled by 32 dampers around the periphery of each tower base. Trickling filter effluent can be recycled. The present mode of operating the trickling filters is to establish a minimum flow rate to the filters, and modulate the valve on the recycle line to maintain the flow rate at or above this minimum setpoint. The settled sewage pumping station appears to be in good condition, though one of the variable speed pumps was observed to vibrate slightly at certain speeds. The trickling filter towers were repaired recently by the addition of a top ring beam, but still exhibit some leakage at joints between the precast wall panels and cast-in-place columns. The concrete underdrain system appears to be in good condition. The trickling filter media modules are nearing the end of their useful life, have become unglued, and are quite brittle especially in the upper layers. It is suspected that some portions of the media are plugged. The rotary distributors are also quite old, show signs of corrosion, and at high flows, wastewater is forced into the oil reservoirs ." 3.2.6 Final Clarification Trickling filter effluent enters a splitter box for division to the two final clarifiers. Each clarifier is a 75-ft diameter center-feed unit with 10-ft side water depth. Sludge from each clarifier is collected by a scraper mechanism and pumped by a dedicated centrifugal pump to the sludge thickeners. Each pump has a 210 gpm capacity at 26-ft IDH, and is operated on a timer basis. Skimmings are collected and pumped by a centrifugal pump rated for 210 gpm at 23-ft IDH. The splitter box and slide gates are in good condition. The final clarifiers are in good shape structurally, but the groundwater relief system gates are inoperable. The clarifier drives were rebuilt after the flood of 1993 and appear to be in good condition. The sludge and scum pumps are in fair condition, though the sludge pumps may be slightly undersized. 3.2. 7 Final Discharge Final effluent flows by gravity to the Missouri River through 2,000 lineal feet of 54-inch diameter outfall pipe at times when the river stage is less than 24. When the river exceeds this level, flow is lifted by three vertical turbine pumps located in the high water pump station. Two are rated for 3,900 gpm at 7-ft IDH and the third is rated for 5,450 gpm at 7-ft IDH. The pumps appear to be operable and in good condition. 3-6 I I I I I I I I I I I I I I I I I I 3.2.8 Plant Water A small portion of the fmal effluent may be pumped for use in the plant as non-potable service water by two 600 gpm pumps (120-ft TDH) and one 120 gpm pump (70-ft TDH). Normally, only one of these pumps is operating when demand exists. 3.2.9 Sampling Flow is sampled by automatic composite samplers at various locations for process control and for NPDES permit reporting. The following streams are sampled: plant influent, influent including returned flows from sludge processing, primary effluent, trickling filter effluent, and final effluent. 3.2.10 Sludge Thickening Primary and secondary sludges are combined in a splitter box and then split for thickening in two gravity thickeners. The original thickener is a 30-ft diameter unit with a 10-ft side water depth. This unit has minor corrosion on the walls; these corroded areas have been recently recoated. The new thickener is 45-ft diameter with a 1O-ft side water depth. Ferrous chloride can be fed to the thickener feed to enhance performance and control odors. Overflow and skimmings from the thickeners return to the head end of the treatment plant. The plant's existing odor control system has provisions for treating odorous air from the thickeners. Currently, however, the thickeners are not covered, and odors are released to the environment. 3.2.11 Sludge Storage Thickened sludge is pumped by two 64-gpm thickened sludge pumps to a new two-cell thickened sludge storage tank. Each cell of the tank is 28-ft square, is mixed by submersible mixers, and can accommodate up to approximately 100,000 gallons of sludge. The tanks are covered, and the vent lines are equipped with activated carbon canisters for odor control. The storage tanks provide several days of sludge storage, allowing for intermittent operation of the belt filter presses. 3.2.12 Sludge Conditioning and Dewatering Sludge is fed by 175-gpm progressing cavity pumps to two new 2-meter wide belt filter presses for dewatering. The presses are provided with plant water pumps to supply belt wash water, hydraulic power packs, and polymer feed facilities. Hydrogen peroxide can be fed upstream of the filter feed pumps for controlling odors. Odorous air from the belt filter press room is collected for treatment. 3.2.13 Sludge Stabilization and Disposal Dewatered sludge is stabilized by the addition of quick lime in sufficient quantity to raise the pH to a value of 12 for at least two hours. The dewatered sludge is loaded onto trucks and hauled to nearby farm fields where it is applied as a soil conditioner and fertilizer. 3.2.14 Odor Control Odorous air from the aerated grit basins and belt filter press room is treated in a new biofiltration system that is sized for 5,900 cfm air containing an average of 3 ppm hydrogen sulfide. The system has capacity to accept additional odorous air from the sludge thickeners, should they be covered in the future. 3-7 I I I I I I I I I I I I I I I I I I 3.2.15 Buildings In general, the buildings are in good condition, although many doors and windows either need replacement or new hardware. HV AC systems are inadequate in the sludge hopper building, main garage, primary solids/grit building, and main building. The size and layout of offices, laboratory, and employee facilities (locker rooms and lunch room) is inadequate for current staffing levels. 3.2.16 · Electrical Systems In general, the electrical systems at the plant are old and in questionable condition. Most systems were submerged during the flood of 1993 and have been repaired. Motor control centers and breakers are generally in fair to poor condition, and are difficult to repair and/or expand due to the inability to get replacement parts. Transformers are old and relatively inefficient. The condition of underground ductbanks is suspect. Several buildings need rewiring. 3.3 Performance and Capacity of Existing Plant The existing Water Pollution Control Facility generally produces an effluent quality of 30 to 40 mg/1 BODs on a monthly average basis, and 20 to 30 mg/1 TSS. Performance is generally better in the warmer summer months than in winter. An evaluation of the capacity of the existing treatment plant was made as part of the facility planning effort. Design guidelines from the Missouri Department ofNatural Resources (10 CSR 20-Chapter 8) were used as an initial basis for determining treatment capacity. These were supplemented with guidelines from the Great Lakes -Upper Mississippi River Wastewater Committee (Ten States Standards) and the Water Environment Federation's Manual of Practice. Actual operating data were also analyzed to assess plant performance under various loading conditions. 3.3.1 Influent Pump Station and Force Mains The Walnut Street Pump Station was originally designed for a flow capacity of 18 mgd. However, pump station performance testing of the existing system demonstrated a maximum flow capacity of about 15 mgd. The new 30-inch diameter river crossing force main, in conjunction with the buried parallel 24-inch diameter force mains on the north side of the river, has a design capacity of30 mgd. 3.3.2 Preliminary and Primary Treatment The inlet screening structure was designed to properly handle up to 20 mgd flow, but can probably handle flows up to 30 mgd before overflowing. The influent Parshall flume can measure flow rates up to 34 mgd. The capacity of the existing grit removal system is considered to be 20 mgd. Above this flow rate, the grit basin outlet weirs cause the water level in at the Parshall flume outlet to back up, reducing the flow measurement accuracy of the flume . With all four units in operation, the primary clarifiers are adequately sized to handle an average daily flow of 11 mgd, and a peak hourly flow of 17 mgd, based on Missouri DNR design 3-8 I I I I I I I I I I I I I I I I I guidelines. While the weir loading rate at the current maximum influent flow rate exceeds the MoDNR design guideline, actual operating data show no significant performance reduction. 3.3.3 Secondary Treatment The capacities of the trickling filters and final clarifiers were evaluated as a combined system because the performance of the secondary treatment system depends both upon the soluble BOD removal of the filters and the suspended solids removal of the final clarifiers. System performance is dependent on flow rate, BOD concentration, and temperature. Recent system performance was evaluated using the Germain formula. Based on this analysis, it appears that the secondary treatment process has a capacity ranging from 8.5 mgd in winter to 16.5 mgd in summer. One of the major factors limiting performance is that the fmal clarifiers are significantly undersized, having a peak hourly flow capacity of only 7.1 mgd based on Mo DNR design guidelines. While the system analysis showed that the actual clarifier capacity exceeds this value, solids carryover becomes a significant concern at higher flow rates. From a purely hydraulic standpoint, the rotary distributors have a total maximum hydraulic capacity of about 19.6 mgd with the currently installed orifices. At high flows, however, water can be forced into the oil reservoirs, and flows in excess of about 20 mgd will likely cause the trickling filter outlet boxes and final clarifier weirs to flood. 3.3.4 Plant Outfall The outfall sewer consists of approximately 2,000 lineal feet of 54-inch diameter pipe discharging to the Missouri River at River Mile 143.3. The flow capacity of the line is dependent on river stage. Under gravity flow conditions, the capacity of the line exceeds 50 mgd at river stages less than 20, but this drops off rapidly at higher stages, particularly above stage 24. With the high water pump station in operation, flows of up to 25 mgd can theoretically be handled to river stage 34, although the installed pump capacity limits actual operation to 19 mgd. Above stage 34, the outfall's hydraulic capacity rapidly decreases. 3.3.5 Sludge Processing The existing sludge processing system is sized to be operated only for one shift on weekdays. Consequently, it has significant excess capacity that could be utilized if sludge processing were to be expanded beyond a one-shift operation. The existing facilities have sufficient capacity to handle the solids produced from an average daily flow of at least 20 mgd. Sludge dewatering would likely become a two-shift process at average daily flows above 14 mgd. 3.4 Summary of Plant Condition and Capacity While the existing Water Pollution Control Facility currently meets its permit limitations, the plant is currently at its treatment capacity (8.5 mgd) during the winter months. Future flow increases will continue to stress the performance of the plant. Hydraulically, the existing plant capacity is limited to about 20 mgd. Many of the wastewater treatment units are reaching the end of their useful lives and will require repairs or replacement to continue offering reliable service. The recently renovated sludge handling systems are in good condition and have adequate capacity to serve the facility in future years. 3-9 I I I I I I I I I I I I I I I I SECTION 4 EVALUATION AND SELECTION OF IMPROVEMENTS 4.1 Design Wastewater Characteristics Currently, the City of Jefferson Water Pollution Control Facility receives wastewater with the following characteristics: Average Daily Flow Average Influent BODs Average Influent TSS 8.5 mgd 200 mg/1 235 mg/1 Design wastewater flows, as previously discussed in Section 2,and wastewater characteristics for the year 2020 are as follows: Daily average flow Peak hourly flow Peak wet weather flow BODs TSS 11 25 60 210 19,260 235 21,500 mgd mgd mgd mg/1 lb/day mg/1 lb/day The year 2020 BODs and TSS loadings include allowances for projected population growth at rates of 0.17 lb BODs per capita per day and 0.2 lb TSS per capita per day, as well as an allowance for projected commercial and industrial growth. · 4.2 Receiving Water Considerations The Missouri River at City of Jefferson is a Class P receiving stream -one that maintains permanent flow even in drought periods. Designated protected uses for the river are as follows: • Irrigation • Livestock and wildlife watering • Warm water aquatic life & human health protection (fish consumption) • Boating and canoeing • Drinking water supply • Industrial use The Missouri River is included on Missouri DNR's Final 1998 Section 303(d) List of impaired waters. The listing of the Missouri River is due to habitat loss from channelization, rather than failure to meet water quality standards for any particular pollutant(s). No TMDLs have been proposed for any pollutants for the receiving stream. The river has an average daily flow in excess of 63,000 cfs at the City of Jefferson. The estimated flow associated with a 1 00-year flood event is 550,000 cfs. The impact on the river of the current discharge (13 cfs average daily flow) as well as the future discharge (17 cfs average daily flow) from the City of Jefferson Water Pollution Control Facility is negligible. 4-1 I I I I I I I I I I I I I I I 4.3 Emuent Limitations Eftluent limitations for the City of Jefferson Water Pollution Control Facility will have to meet one or more of the following sets of requirements, depending on the fmal treatment process selection: 4.4 Trickling Filter Plant BODs monthly average BODs weekly average TSS monthly average TSS weekly average pH all times New Trickling Filter Plant BODs monthly average BODs weekly average TSS monthly average TSS weekly average pH all times Activated Sludge Plant BODs monthly average BODs weekly average TSS monthly average TSS weekly average pH all times 45 mg/1 65 mg/1 45 mg/1 65 mg/1 6to 9 40 mg/1 60 mg/1 40 mg/1 60 mg/1 6to9 30 mg/1 45 mg/1 30 mg/1 45 mg/1 6to9 Peak Excess Flow Treatment Facility BODs weekly average 45 mg/1 TSS weekly average 45 mg/1 pH all times 6 to 9 Treatment Plant Site Requirements Several different locations were considered for locating the new or expanded wastewater treatment facilities: • Locating part or all of the wastewater treatment facilities on the south side of the Missouri River, at or near the Walnut Pump Station, and continuing to use the existing sludge processing facilities on the north side of the river. • Locating the wastewater treatment facilities on the north side of the Missouri River, adjacent to .the existing sludge processing facilities at the Water Pollution Control Facility, • Locating the wastewater -treatment facilities on the north side of the river, at a location distant from the existing sludge processing facilities at the Water Pollution Control Facility. Advantages and disadvantages of the different location options are presented in Table 4-1. 4-2 -------------- TABLE 4-1 COMPARISON OF SITE LOCATION OPTIONS Option Advantages Disadvantages Locating part of the wastewater treatment • Minimizes pwnping of flow across • Limited availability and high cost of land on facilities on the south side of the Missouri the Missouri River south side of river River, at or near the Walnut Pwnp Station, • Greater impact from potential odor releases and continuing to use the existing sludge • Higher operating and maintenance costs for processing facilities on the north side of facilities split between south and north side the river of river Locating the wastewater treatment • Minimizes operating & • Higher O&M costs for pwnping of all facilities on the north side of the Missouri maintenance costs due to co-located wastewater (dry and wet weather) flows i River, adjacent to the existing sludge wastewater and sludge processing across the Missouri River I processing facilities at the Water Pollution facilities Control Facility. Locating the wastewater treatment • Situates the wastewater treatment • Higher operating and maintenance costs for facilities on the north side of the river, at a facilities farthest from populated non-adjacent wastewater and sludge location distant from the existing sludge areas processing facilities processing facilities at the Water Pollution • Higher O&M costs for pwnping all Control Facility. wastewater (dry and wet weather) flows across the Missouri River plus the additional distance down-river to the new plant • Higher O&M costs for pwnping sludge and filtrate streams between facilities -------·-- I I I I I I I I I I Based on a review of the advantages and disadvantages of the various options, it appears that the best option, at least for dry weather flows, is to locate the wastewater treatment facilities on the north side of the Missouri River, adjacent to the existing sludge processing facilities at the Water Pollution Control Plant. The disadvantages associated with the other location options outweigh the benefits of these alternatives. 4.5 Alternatives In order to meet the secondary effluent limitations identified in Section 4.3, several biological treatment alternatives were evaluated including activated sludge processes (conventional continuous-flow versus sequencing batch reactors) and aerobic attached-growth processes (trickling filters). Because of the extreme difference between the average dry weather flow and peak wet weather flow, a ballasted coagulation treatment system was also evaluated for treatment of wet weather flows that exceed the practical capacity of biological treatment systems. 4.5.1 Activated Sludge Options Two different types of suspended growth activated sludge systems were considered for the new wastewater treatment facilities: • A standard continuous-flow activated sludge system consisting of aeration tanks operating at an F:M ratio of 0.2 lb BODs/dayllb ML VSS, and secondary clarifiers loaded at a peak rate of 1 ,200 gpdlttl. • A sequencing batch reactor plant consisting of parallel batch reactors operating at an F:M ratio of 0.1 lb BODs/day!lb ML VSS. One of the major concerns with any suspended growth system is the ability of the system to withstand peak hydraulic flows without washing substantial portions of the active biomass out of the system. To be able to retain biomass in the treatment system at peak wet weather flows of 60 mgd, a continuous flow-through activated sludge system would need to be eqwpped with . significantly over-sized final clarifiers. A sequencing batch reactor plant, on the other hand, would simply revert to shorter cycle times or parallel reactor operation under peak flow conditions, and thus would be able to safely retain biomass in the reactors. A sequencing batch reactor (SBR) treatment system was chosen over conventional flow-through activated sludge systems for further evaluation, because the SBR system would have lower capital costs, a smaller plant footprint, and a higher degree of operational flexibility. Footprint requirements and capital costs are less for the SBR system because both aeration and settling are performed within a single reactor tank whereas separate tankage is required for conventional continuous flow-through systems. Additionally, the SBR tankage does not need to be oversized to the same degree as conventional final clarifiers would be to handle peak wet weather flows. The SBR treatment system is operationally more flexible, and more resistant to shock loadings than are conventional continuous flow systems. A sequencing batch reactor (SBR) is a fill and draw activated sludge treatment system, and as such is quite capable of treating the municipal and light industrial wastewater streams. The processes involved in an SBR system are identical to a conventional continuous-flow activated sludge system with the exception that all processes are carried out sequentially in the same reactor tank. Since the SBR operates on the fill and draw principle, two or more reactor tanks 4-4 I I I I I I I I I I I I I are usually employed so that one tank receives influent wastewater while the other tank(s) are carrying out the treatment cycle. An SBR system incorporates five major treatment steps, which are carried out in sequence as follows: • FILL • REACT (Aeration) • SETTLE (Sedimentation/Clarification) • DRAW (Decant) • IDLE (Sludge Wasting) During the FILL step, raw wastewater is introduced to the reactor tank. Since the reactor tank acts as an equalization basin during the FILL step, it can tolerate greater peak flows and/or shock loadings of Biochemical Oxygen Demand (BOD) without degradation of effluent quality. During the REACT step, mixing and aeration of the reactor tank contents occur to achieve the treatment objectives. Levels of treatment can be optimized by varying the duration and dissolved oxygen concentration of the reactor tank during this step. During the SETTLE step, solids separation occurs to provide a clarified supernatant for effluent discharge. Since this step occurs under nearly ideal quiescent conditions (no water inflow or outflow) the solids separation is very good. During the DRAW step, treated clarified water is removed from the reactor tank by a decant mechanism (gravity flow or by pumping). The IDLE step is the time between treatment cycles in the reactor tank. During this step, accumulated excess sludge is wasted. Waste sludge would be treated by the existing sludge treatment facilities. One of the key advantages of the SBR treatment option is the system flexibility over the plant life cycle. Precise control of the volume of wastewater and the time associated with each of the treatment steps means that that the system can be operated to achieve a variety of treatment objectives. Additionally, nitrification, denitrification, and phosphorous removal are ·achievable with an SBR system without chemical addition. This is important for being able to handle possible future changes in regulatory effluent discharge limits, and to handle wastewaters from possible future industrial clients seeking to develop in the Jefferson City area. Some additional advantages of an SBR treatment system are the flow and waste loading equalization inherent in the fill and draw treatment cycle. This also assures that hydraulic surges will not result in ''washout" of the reactor mixed liquor solids. Recycle of the mixed liquor activated sludge is not required as in conventional continuous flow activated sludge systems since it always remains in the reactor tank. Highly efficient clarification is achievable under the almost quiescent settling conditions. Filamentous growth can be easily controlled by varying the operating strategies during the FILL step. Lastly, objectionable odors are not typically a problem with activated sludge treatment processes. Some disadvantages of an SBR treatment system are the increased complexity and sophistication of the control systems required to meet the treatment objectives under various influent conditions. Additionally, higher power consumption is associated with the SBR treatment process (as with any activated sludge treatment process), in comparison to trickling filters. 4-5 I I I I I I I I I 4.5.2 Trickling Filtration Aerobic attached-growth treatment processes (trickling filters) were evaluated as a treatment alternative because that is the current process being utilized at the City of Jefferson WPCF. The process is familiar to the current plant operations staff, and this treatment alternative would involve expansion of existing facilities. The trickling filter process is preceded by primary clarification to remove suspended solids and organic matter that can easily be removed by the sedimentation process. The trickling filters consist of beds of highly permeable plastic media to which microorganisms are attached. The influent wastewater is distributed over the top of the media by a rotary distributor. The wastewater percolates through the media, where the microorganisms degrade the organic material present in the wastewater. During the treatment process, a biological film or slime layer builds on the filter media as the organic material is degraded. As the biological film layer builds in thickness, it reaches a point where it can no longer adhere to the media surface, and sloughs off into the filter underdrain system. A portion of the water collected in the underdrain system may be recycled to the trickling filters to dilute the strength of the influent wastewater, and to maintain the biological film layer in a moist condition. The trickling filters are followed by secondary clarification to remove the suspended solids and biological film sloughed off of the filter media. Maintaining the correct hydraulic loading rate for the trickling filters is essential to good operating performance. Too low a rate will result in excess biomass accumulation within the trickling filter and subsequent odor problems. Too high a rate can damage the media, reduce performance, and cause too much biomass to slough off. Advantages of the trickling filter treatment process are its operational simplicity and the familiarity of the process to the current plant operating staff. Under most conditions, the power costs associated with a secondary treatment trickling filter process will be considerably lower than those associated with an activated sludge process. One disadvantage of the trickling filter process is that the level of treatment achievable is not as good as that from an activated sludge process. Additionally, the trickling filter process is susceptible to poor eftluent quality due to either hydraulic or organic shock loadings. Another key disadvantage to the trickling filter process is that under certain operating conditions, noticeable odors emanating from the process will have to be controlled. Trickling filters characteristically emit from one-third to two-thirds of any dissolved gaseous odors (e.g., hydrogen sulfide) present in the feed to the filters. In addition, complex reduced sulfur compounds such as mercaptans are formed within the biomass of even well-operated trickling filters . A fraction of these odors also escape as the filters are ventilated. 4.5.3 Ballasted Coagulation A ballasted coagulation treatment technology was evaluated as a treatment alternative for the peak wet weather flows. Ballasted coagulation is a high efficiency clarification system using microsand-enhanced flocculation and settling for removal of influent suspended solids. The microsand serves as a flocculent aid and a ballasting agent allowing overflow rates as high as 80 gpm!ttl in wastewater treatment applications. An eftluent quality of 45 mg/1 for BODs and TSS 4-6 I I I I I I I I should be achievable for treated wet weather flows. The process uses flash mixing with a chemical coagulant and the introduction of the microsand in an injection tank. The wastewater then flows to a maturation tank where slow mixing aids in the formation of floc particles. The final step is a Lamella plate clarifier where the suspended solids are settled out. The settled sludge from the classifier is run through a hydrocyclone where the microsand particles are separated for reuse in the treatment process. Waste sludge would be forwarded to the existing sludge handling facilities. Advantages of the ballasted coagulation technology over conventional clarifier systems are that reduced capital costs and a significantly smaller facility footprint are possible due to the high clarifier overflow rates achievable. Better treatment performance is also generally possible. Disadvantages of the ballasted coagulation technology include high operating costs when the system is in operation, due to high coagulant chemical consumption rates. 4.6 Evaluation of Alternatives Evaluation of treatment alternatives for the Jefferson City Water Pollution Control Facility is complicated by two factors: • First, the primary collection point and pump station for the facility is located on the south side of the Missouri River at the Walnut Street Pump Station, while the existing wastewater and sludge treatment facilities are located on the north side of the river. • Second, the range of average dry weather flows to peak wet weather flows requiring treatment is large. These factors impact the equipment sizing and location of the proposed treatment alte~atives. Several components of the treatment alternatives for the City of Jefferson Water Pollution Control Facility are common to all of the alternatives. These include a new plant headworks located on the north side of the Missouri River. The age and condition of the existing plant headworks as well as the design capacity and current operational problems associated with the existing headworks will require it to be replaced. The new -plant head works will consist of screening of the influent wastewater and grit removal, and will be sized to accommodate the influent flow rate required for each of the alternatives. Portions of the head works will be located indoors to facilitate winter operation and odor control. A new 60 mgd Walnut Street Pump Station, located on the south side of the Missouri River, is common to all of the treatment alternatives. Modeling of the City of Jefferson sewer system provided results indicating a peak wet weather flow of 60 mgd requiring treatment. The existing Walnut Street Pump Station has mechanically and electrically reached the end of its useful life, and an evaluation concluded that the existing station could not be expanded beyond a 40 mgd pumping rate. Additional upgrades would be required to bring the existing facility into compliance with current MoDNR regulations regarding elimination of the existing bypass structure, providing 100 year flood protection, and provisions for emergency operation (power generation). The evaluation concluded that it would be more beneficial to provide a new facility capable of handling the full 60 mgd flow rather than upgrading the existing facility to its 4-7 I I I I I I I I maximum capacity and providing a supplemental pump station to handle the peak flows. To minimize pump station footprint and capital costs, a submersible pump station designed to handle the peak wet weather flows is included for each of the alternatives. The need for installation of a new 30-inch diameter force main under the Missouri River was evaluated for each of the alternatives. The capacity of the existing force main system is half of that required for the peak wet weather flow. Some of the treatment alternatives considered placing a wet weather treatment process on the south side of the river to eliminate the need for a second wastewater force main. This approach leads to other items which must be included in the overall evaluation including the need for redundancy in the force main system, operation and maintenance of two separate treatment facilities, land availability for an additional treatment system located on the south side, and public perception of a treatment facility in that location. A new Office/ Administration building located at the treatment plant is included for all of the treatment alternatives. The size and functionality of the existing administration building is insufficient for long-term operation of the plant. Additionally, the Missouri River Levee System Unit L142 proposed by the Corps of Engineers would eliminate access to the treatment plant and the existing administration building from Mokane Road, requiring the new plant access to be located on the north side of the existing facility. The following treatment alternatives incorporate various combinations of the aforementioned treatment processes and system components to identify the best treatment option for the present and future needs of City of Jefferson. 4.6.1 Alternative No.1 Alternative No. 1 consists of expanding the existing trickling filter plant to handle the future 11 mgd dry weather flow. This expanded facility would also handle peak hourly flows of up to 25 mgd, the practical upper limit for the secondary treatment trickling filters. Wet weather flows in excess of the 25 mgd peak capacity would be treated in a new ballasted coagulation system located on the south side of the Missouri River. Figure 4-1 presents a schematic of this alternative. The primary components for this alternative include a new 60 mgd Walnut Street Pump Station and a new 35 mgd peak wet weather flow treatment system located on the south side of the Missouri River. Upgrades required for the existing wastewater treatment plant located on the north side of the Missouri River to increase capacity to 11 mgd average flow and 25 mgd peak flow include a new 25 mgd plant headworks, one new 65-foot diameter trickling filter tower, and two new 90-foot diameter final clarifiers. The two existing trickling filters would be rehabilitated with new media and rotary distributors. Both the old and new trickling filters would be equipped with covers and odor control equipment. Various repairs and modifications to the remaining facilities would be included in the project to extend the useful life of the facility for the planning period. Estimated capital improvement costs total $18,860,000 and the estimated annual operation and maintenance costs total $1 ,31 5,994 per year for this treatment alternative. The developed cost 4-8 ---~·-------------- .____.PLANT WATER HIGH WATER PUMP STATION (NEW PUMPS) EXISTING PRIMARY CLARIFIERS ----------------------·-- MISSOURI RIVER NEW HEADWORKS -~ --------~----------__ _! _________ _ 35MGD PEAK' I I NEW WET-WEATHER FLOW TREATMENT NEW I MODIFIED WALNUT PUMP STATION FIGURE4-1 ALTERNATIVE NO. 1 ONE NEW 65-FT+ TRICKLING FILTER I I I I I I I I I I I I I I I I I I I I estimates are included in the Appendix. A lifecycle cost comparison of all of the alternatives is included in Section 4.7. Advantages of this treatment alternative are: • Meets current effluent discharge requirements. • Has the lowest capital cost (excluding land acquisition). • Has the lowest annual operation and maintenance cost. • Utilizes most of the existing structures at the WPCF. • The process is simple to operate, and is familiar to the operating staff. Disadvantages of this treatment alternative are: • Physical separation of the two main treatment processes. • Additional costs will be incurred for land acquisition and development on the south side of the river. • Public resistance to treatment facilities being located on the south side of the river. • Lack of a redundant river crossing force main. • High odor potential due to the operational reliability of odor control equipment associated with the trickling filter towers. • The process does not have the flexibility to meet possible future regulatory discharge limits for nutrient removal or future industrial waste streams. 4.6.2 Alternative No.2 Alternative No. 2 is essentially the same as Alternative No. 1, except that the peak wet weather flow treatment system has been moved to the north side of the Missouri River at the existing treatment plant facility. Refer to Figure 4-2 for a schematic of Alternative No.2. Additional components required for this alternative include providing a second 30-inch diameter force main under the river, a new larger headworks, and a new high water pump station. These additional components are required for conveying and treating the entire peak flow capacity of 60 mgd on the north side of the Missouri River. Estimated capital improvement costs total $22,980,000 and the estimated annual operations and maintenance costs total $1,318,970 per year for this treatment alternative. The developed cost estimates are included in the Appendix. A lifecycle cost comparison of all of the alternatives is included at the end of this Section. 4-10 ~-------------------- NEW SPLITTER BOX AND WET-WEATHER FLOW TREATMENT 1.. I 35MGD PEAK PLANT WATER NEW HIGH WATER PUMP STATION EXISTING PRIMARY CLARIFIERS MISSOURI RIVER NEW HEADWORKS ADDITIONAL FORCE MAIN --- --- NEW I MODIFIED WALNUT PUMP STATION SETIELD &:WAGE PUMP STATION (NEW PUMPS) !... ...................................................................................................................................... ..1 FIGURE 4-2 ALTERNATIVE NO.2 RECYCLE LINE ONE NEW 65-FT+ TRICKLING FILTER I I I I I I I I I I I I I I I I I I I Advantages of this treatment alternative are: • Meets current effluent discharge requirements. • Centralizes the location of the treatment processes at the existing Water Pollution Control Facility. • Has a low annual operation and maintenance cost. • Utilizes most of the existing structures at the WPCF. • The process is simple to operate, and is familiar to the operating staff. • Provides for a redundant river crossing force main. Disadvantages of this treatment alternative are: • Has the highest capital improvement cost. • High odor potential due to the operational reliability of odor control equipment associated with the trickling filter towers. • The process does not have the flexibility to meet possible future regulatory discharge limits for nutrient removal or future industrial waste streams. 4.6.3 Alternative No.3 Alternative No. 3 consists of replacing the existing wastewater treatment facilities with a new Sequencing Batch Reactor (SBR) plant designed for the 11 mgd average flow rate and a 30 mgd peak flow rate. Sizing of the SBR plant in this alternative was to match the hydraulic capacity of the existing 30-inch diameter force main under the river. An additional wet weather treatment system, located on the south side of the Missouri River, and utilizing ballasted coagulation treatment technology, is required to handle the remaining peak flows in excess of the 30 mgd. Figure 4-3 provides a diagram of the proposed treatment alternative. · The primary components for Alternative No. 3 include a new 60 mgd Walnut Street Pump Station and a new 30 mgd peak wet weather flow treatment system located on the south side of the Missouri River. The new 30 mgd treatment facility on the north side of the river would include a new plant headworks, four separate sequencing batch reactor basins, and new larger pumps in the existing high water pump station. Estimated capital improvement costs total $22,560,000 and the estimated annual operations and maintenance costs total $1,395,314 per year for this treatment alternative. The developed cost estimates are included in the Appendix. A lifecycle cost comparison of all of the alternatives is included in Section 4.7. Advantages of this treatment alternative are: • Low odor potential associated with the activated sludge treatment process. • Meets current effluent discharge requirements and has the potential to meet possible future regulatory discharge limits for nutrient removal or future industrial waste streams. • Incorporates all new treatment facilities. 4-12 ------------------------- ~· 11 MGDAVG. I -- '" 30 MGD PEAK ___.PLANT ' WATER -HIGH WATER PUMP STATION (NEW PUMPS) NEW -HEADWORKS ----~-----=--.. -- MISSOURI RIVER ,----~ ~ ~ --_;; --~ I NEW I MODIFIED ... WALNUT PUMP 30MGD STATION PEAK • ~ t FLOW TREATMENT ALTERNATIVE NO.3 I I I I I I I I I I I I I I I I I I I I Disadvantages of this treatment alternative are: • Physical separation of the two main treatment processes. • Additional costs will be incurred for land acquisition and development on the south side of the river. • Public resistance to treatment facilities being located on the south side of the river. • Has a high capital improvement cost. • Has the highest annual operation and maintenance cost. • Lacks a redundant river crossing force main. • Abandons the existing treatment facility structures. • New treatment processes to learn with the SBR plant and the wet weather ballasted coagulation facility. 4.6.4 Alternative No. 4 Alternative No. 4 consists of replacing the existing treatment plant facility with a new Sequencing Batch Reactor (SBR) plant designed for the 11 mgd average flow and 30 mgd peak flow. The existing primary and secondary clarifiers would be reconfigured to provide primary clarification for wet weather flows in excess of 30 mgd. Figure 4-4 provides a diagram of the proposed treatment alternative. Components required for this alternative include providing a new 60 mgd Walnut Street Pump Station and a second 30-inch diameter force main under the river, a new 60 mgd headworks and splitter box, four separate sequencing batch reactor basins, and a new high water pump station. Estimated capital improvement costs total $22,650,000 and the estimated annual operations and maintenance costs total $1,354,848 per year for this treatment alternative. The developed cost estimates are included in the Appendix. A lifecycle cost comparison of all of the alternatives is included in Section 4.7. Advantages of this treatment alternative are: • Centralizes the location of the treatment processes at the existing Water Pollution Control Facility. • Low odor potential associated with the activated sludge treatment process. • Meets current effluent discharge requirements and has the potential to meet possible future regulatory discharge limits for nutrient removal or future industrial waste streams. • Provides for a redundant river crossing force main. • Utilizes existing clarifier structures. 4-14 ------------------- PLANT WATER NEW HIGH WATER PUMP STATION EXISTING PRIMARY CLARIFIERS 11 MGDAVG. 30MGDPEAK ----------MISSOURI RIVER --· --- NEW HEADWORKS ADDITIONAL FORCE MAIN NEW I MODIFIED WALNUT PUMP STATION FIGURE4-4 AL TERNATIVE NO.4 NEW SEQUENCING BATCH REACTOR PLANT EXISTING SECONDARY CLARIFIERS I I I I I I I I I 'I I I I I I I I I I Disadvantages of this treatment alternative are: 4.6.5 • Has a high capital improvement cost. • Has a high annual operation and maintenance cost. • Marginal ability of the existing clarifiers to meet effluent discharge limitations for the maximum wet weather flows. • Odor potential for existing clarifiers if not drained and properly maintained after wet weather treatment. • Reliability and maintenance of the existing clarifiers being used for periodic wet weather flow events. • New treatment process to learn with the SBR plant. Alternative No.5 Alternative No. 5 consists of replacing the existing treatment plant facility with a new Sequencing Batch Reactor (SBR) plant designed for the 11 mgd average flow and 60 mgd peak wet weather flow. The existing wastewater treatment facilities would be abandoned. Components required for this alternative include a new 60 mgd Walnut Street Pump Station, a second 30-inch diameter force main under the river, a new 60 mgd headworks and splitter box, four separate sequencing batch reactor basins, and a new high water pump station. Figure 4-5 provides a diagram of the proposed treatment alternative. Estimated capital improvement costs total $22,71 0,000 and the estimated annual operations and maintenance costs total $1,320,106 per year for this treatment alternative. The developed cost estimates are included in the Appendix. A lifecycle cost comparison of all of the alternatives is included in Section 4.7. Advantages of this treatment alternative are: • Centralizes the location of the treatment processes at the existing Water Pollution Control Facility. • Utilizes a single treatment process for all flows. • Low odor potential associated with the activated sludge treatment process. • Meets current effluent discharge requirements and has the potential to meet possible future regulatory discharge limits for nutrient removal or future industrial waste streams. • Provides for a redundant river crossing force main. • Relatively low operation and maintenance cost. Disadvantages of this treatment alternative are: • Has a high capital improvement cost. • New treatment process to learn with the SBR plant. 4-16 ~----------~------- __,.., 11 MGDAVG. I 60MGDPEAK I .,... PLANT WATER -,_ NEW HIGH WATER PUMP NEW STATION HEADWORKS ADDITIONAL FORCE MAIN -~ MISSOURI RIVER -- NEW I MODIFIED WALNUT PUMP STATION ALTERNATIVE NO. 5 I I I I I I I I I I I I I I I I I 4.6.6 Alternative No. 6 Alternative No. 6 is the No-Action alternative which would continue the current practice of bypassing the peak wet weather flows in excess of the current treatment plant capacity directly to the Missouri River or tributary streams, in violation of the SSO control policy. Reliability of the No-Action alternative is poor. The evaluation of the existing treatment facilities (See Section 3) indicates that many treatment components are approaching the end of their useful service life. Repair and/or replacement of these components would be required even to maintain the current level of treatment at the facility. Environmental impacts from the No-Action alternative include untreated SSO discharges to the Missouri River and tributary streams due to the inability of the existing collection system, pump station, and treatment facility to handle peak wet weather flows in excess of 18 mgd. Additionally, the frequent odor problems associated with the existing trickling filters would not be addressed under the No-Action alternative. 4. 7 Selected Alternative and Site The alternatives presented above were evaluated to determine which alternative best meets the needs of the City during the 20 year planning period while also providing flexibility to respond to future growth and or regulatory requirements. Preliminary design criteria have been developed for the selected alternative. These will be the basis for the final design documents that will be developed in the next phase of the project. 4.7.1 Comparison of Alternatives The alternatives have been evaluated to determine which alternative best meets the needs of the City. The key factors in the evaluation are presented in Table 4-2. The first part of the table presents estimated capital and operating costs. These are presented in year 2000 dollars and also as present worth assuming a 20 year period and 5.5% interest. The present worth values make it possible to compare the costs on a life cycle basis. The second part of the table ranks the impact of the alternatives in several areas that are of interest to the public, regulatory agencies and the plant staff. Taking all of the impact factors into account, Alternative 5 appears to best meet the needs of the interested parties. Based on the evaluation, Alternative 5, a new SBR system capable of treating both dry and wet weather flows in a single system, is the selected alternative. The basis for that selection is discussed below. The no action alternative, Alternative 6, is not an acceptable alternative and is not further discussed. No action is eliminated because the current treatment system is at capacity and can not accept future dry weather flows, periodic treatment plant odors must be eliminated and action must be taken to deal with significant wet weather overflows from the collection system. 4-18 I I I I I I I I I I I I I I I I I I I 4.7.1.1 Alternative Summary Alternative 1 • 25 mgd peak upgraded trickling filter system • 35 mgd peak wet weather treatment at Walnut Pump Station Alternative 2 • 25 mgd peak upgraded trickling filter system • 35 mgd peak wet weather treatment at WPCF site • New 30-inch force main Alternative 3 • 30 mgd peak SBR • 30 mgd wet weather treatment Walnut Pump Station Alternative 4 • 30 mgd peak SBR • 30 mgd wet weather treatment using existing clarifiers • New 30-inch force main Alternative 5 • 60 mgd peak SBR • New 30-inch force main 4-19 ------------------- COST SUMMARY* Type of Cost Capital Cost Annual O&M Cost Present Worth of O&M Costs Total Present Worth EVALUATION RANKING** Type of Impact Capital Cost O&MCost Odor Potential River Crossing Redundancy Treatment Flexibility Environmental Impact Public Acceptance Total • Present Worth based on: n = 20 years i = 5.5% •• Ranking 1 = Most Favorable 5 = Least Favorable TABLE4-2 COMPARISON OF ALTERNATIVES Alternative 1 Alternative 2 Alternative 3 Alternative 4 $ 18,860,000 $ 22,980,000 $ 22,560,000 $ 22,650,000 $ 1,315,994 $ 1,318,970 $ 1,395,314 $ 1,354,848 $ 15,726,637 $ 15,762,191 $ 16,674,532 $ 16,190,950 $ 34,586,637 $ 38,742,191 $ 39,234,532 $ 38,840,950 Alternative 1 Alternative 2 Alternative 3 Alternative 4 2 5 5 5 2 2 3 3 5 4 3 2 2 1 2 1 5 4 3 2 5 4 3 2 3 3 3 3 24 23 22 18 4-20 Alternative 5 Alternative 6 $ 22,710,000 $ - $ 1,320,106 $ 1,218,850 $ 15,775,772 $ 14,565,724 $ 38,485,772 $ 14,565,724 Alternative 5 Alternative 6 5 1 2 1 1 5 1 2 1 5 1 5 3 5 14 24 I I I I I I I I I I I I I I I I I I 4.7.1.2 Capital Cost The $18.9 million capital cost for Alternative 1 is significantly less than the other alternatives which essentially all have the same capital cost of about $22.7 million. $2.3 million of the $3.8 million difference is in the new 30-inch force main provided under alternatives 2,4, and 5. Land costs are not included in ·the alternatives cost estimates because significant negotiations will be required to determine those costs. However, land costs and associated mitigation could also narrow the difference with Alternative 1 by another $500,000 to $1 million. The only land available near the Walnut Street Pump Station (the cost effective location for south of the river treatment because collection sewers converge at this point and the existing bypass line can be used for discharge to the river) is State of Missouri parking area. Parking space is a valuable commodity and it is anticipated that the State will require equivalent spaces be provided. A parking garage may be the only way to mitigate the lost spaces. 4.7.1.3 Operation & Maintenance Cost Operation and maintenance costs are essentially the same for all five alternatives. The alternatives that include sequencing batch reactors have higher power costs, due to aeration, than the alternatives that include trickling filtration. The alternatives that include sequencing batch reactors have lower sludge processing costs, because the SBR process generates less sludge than trickling filter alternatives. The alternatives that include ballasted coagulation have significant chemical and manpower costs associated with their operation. Overall, the cost factors for the various alternatives offset each other, resulting in annual operating & maintenance costs that vary by only a few percent between the five alternatives. 4.7.1.4 Odor Potential Aside from the need to increase capacity to meet future flow requirements, odor is. the major driver for treatment plant improvements. When trickling filter odors combine with an inversion or light northerly winds, strong odors are apparent in many areas of the City. Trickling filters generate odors in two different ways. By design, trickling filters expose large surface areas of wastewater to the air as the flow is distributed over the filter media Within the two filters at the existing plant, there are over 4 million square feet of filter media surface area. Any dissolved odorous gases, such as hydrogen sulfide, will have an opportunity to escape from the wastewater to the atmosphere as the wastewater trickles over the media. Typically, from one-third to two- thirds of the dissolved hydrogen sulfide will be stripped and exit the filters as odors. The second way in which odors are generated in a trickling filter is that, over time, excess biomass can build up on the media surface. While the outer surface of the biomass is in an aerobic state, the inner layers of a thick biomass will be under anaerobic conditions. Hydrogen sulfide and more complex reduced sulfur compounds, such as methyl mercaptan and dimethyl sulfide, are formed under such conditions. These odorous compounds may escape the biomass gradually, but more typically, they are released in larger quantities when the excess biomass is sloughed off. It is these sloughing episodes that cause the periodic intense odors experienced at the present facility. Other potential sources of odor include the plant headworks, primary clarifiers, activated sludge basins, secondary clarifiers, sludge storage and dewatering facilities, and any peak wet-weather 4-21 I I I I I I I I I I I I I I I flow treatment units. Based on observations of the existing treatment facilities, and typical odor emissions from similar treatment facilities, the potential odor sources included in the five treatment alternatives were ranked in order, from highest to lowest potential to emit odors. The ranking is as follows: • trickling filters • sludge storage/dewatering • plant headworks • primary clarifiers • peak wet-weather flow treatment units • aeration basins • secondary clarifiers Based on this ranking of odor sources, and also taking into consideration the location of the treatment units relative to the city, the five treatment alternatives are ranked as follows in terms of odor generation potential: 4.7.1.5 Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 River Crossing Redundancy highest odor release potential lowest odor release potential Over 90 percent of the City of Jefferson wastewater is collected on the south side of the Missouri River and must be pumped to the north side. There must always be a means to convey the wastewater under the river or it will be discharged untreated. Currently there are two force mains under the river. One of two 24-inch force mains originally installed in 1968 remains. The condition of this main is precarious. During the 1993 flood the high river velocity exposed and severely relocated the mains from their original crossing coordinates. One of the mains failed. Soundings after the flood showed that portions of the remaining main were suspended in the river. The remaining force main may fail at any time. A new 30-inch main was installed in 1995. This main is expected to be in good condition. At reasonable wastewater flow velocities this main has a capacity of 30 mgd. A second 30-inch force main will be constructed with Alternatives 2, 4 and 5. The second force main will provide redundancy should some type of failure or blockage occurs with the existing 30-inch force main. Redundancy is needed because of the long time period (about a year) that will be required to replace the 30-inch force main should some type of major failure occur. It would not be tolerable to allow wastewater to be discharged untreated for an extended period. 4-22 I I I I I I I I I I I I I I I I I I I I I 4. 7 .1.6 Treatment Flexibility The trickling filter system currently providing treatment at the WPCF and the SBR systems considered in Alternatives 3, 4, and 5 provide significantly different degrees of flexibility to deal with future changes in raw wastewater loading and/or eftluent requirements. Typically secondary treatment eftluent is required to meet monthly limits of 30 mg/1 for BOD and suspended solids. This level of treatment can not be achieved with trickling filters. Trickling filter have been used extensively in the past but now are allowed only on large rivers where current water quality criteria still allow the lower degree of treatment. For the existing WPCF system, the monthly average BOD and suspended solids limit is 45 mg/1. For the upgraded system using Alternatives 1 and 2, the monthly average limits would be 40 mg/1 BOD and suspended solids. Another treatment system would have to be added (tertiary treatment) should it ever be required to meet lower BOD or suspended solids limits or to remove nutrients such as phosphorus or nitrogen. The sequencing batch reactor system offers a great deal of flexibility in dealing with present and future treatment needs. By modifying operating cycles and mixed liquor criteria, significant additional waste loads can be handled. With Alternative 5, the tankage will be sufficiently large so as to accommodate dry and wet weather flows in the same system by varying operating cycles. The tanks will be in place to handle new high-BOD industrial sources should such facilities wish to relocate in the City of Jefferson. The SBR system can also be operated to enhance phosphorus and nitrogen removal. While requirements to reduce nutrients are not likely in the next few years, there is increasing concern about nutrient induced dead zones in the Mississippi River delta which may at some point cause limits to be imposed on upstream discharges. Alternative 5 allows the most flexibility because of the large tank volume and ability to treat both dry and wet weather flows in the same system. Alternatives 3 and 4 allow SBR flexibility but only for a portion of the flow. The trickling filter alternatives provide only BOD and suspended solids removal to 40 mg/1. Placing all of the treatment systems at the same location provides flexibility in utilizing operating staff and makes operation more efficient. Therefore Alternatives 2, 4 and 5 receive higher ratings for this aspect of flexibility than Alternatives 1 and 3. 4.7.1.7 Environmental Impact Environmental impacts relate to the removal of pollutants, affects of immediate and long term construction impacts on plants and wildlife and esthetic factors such as impact on the area around the treatment system and historic preservation issues. The SBR alternatives provide a higher degree of treatment and are therefore more environment friendly. Construction impacts will be minor with any of the alternatives. Alternative 5 disturbs more land adjacent to the existing WPCF but avoids construction of wet weather treatment on the south side of the river. A voiding a wet weather treatment system in the vicinity of the Walnut Street Pump Station avoids the esthetic issues associated with a major wastewater treatment system in the vicinity of the State Capitol Building. 4-23 I I I I I I I I I I I I I I I I I Alternative 5 has the most favorable environmental impact because 30 mg/1 BOD and suspended solids effluent is provided for both wet and dry weather flows and because there is no wet weather treatment system near the capital building. Alternative 2 provides 30 mg/1 BOD and suspended solids for some of the wet weather flow and no wet weather treatment near the capital building. Alternative 3 provides the 30 mg/1 treatment level but also includes wet weather treatment near the Walnut Street Pump Station. Alternative 4 avoids treatment near Walnut Street but may have difficulty meeting 45 mg/1 BOD and suspended solids effluent quality for storm flows. Alternative 1 provides the lower degree of treatment and also would have wet weather treatment near the Walnut Street Pump Station. 4.7.1.8 Public Acceptance Public acceptance of the Water Pollution Control Facility improvements is crucial to the advancement of the project to the final design and construction phases. The public will register that acceptance in a bond issue vote. Citizens are expected to have three major concerns: impact of the new facilities on user charges, correction of odor problems that have plagued the City for years and concern about a major wastewater treatment facility in the downtown area. Cost differences, to a great extent, depend on the need for a second force main under the Missouri River. The impact of this cost difference is reduced by the high cost of obtaining and mitigating land for a wet weather treatment system (see Capital Cost above). Odor control will be provided with all of the alternatives but that control will be most positive with the SBR systenis, especially with Alternative 5 which treats all flows in the SBR. Odor control will be somewhat less positive with the non-SBR (trickling filter and wet weather treatment) systems. Wet weather treatment in the downtown area is considered potentially more troublesome than at the WPCF site. The public is not expected to favor a major wet-weather treatment system in the downtown area. Weighing public acceptance of lower cost with the desire for the most positive odor control and avoiding treatment downtown, all of the alternatives have been given a neutral ranking of 3 for public acceptance. · 4.7.2 Selected Alternative With the exception of cost, Alternative 5 showed a ranking equal to or better than the ranking for the other alternatives. Alternative 5 has a capital cost significantly higher than the lowest cost alternative, Alternative 1. Operating costs for all the alternatives are essentially the same. Alternative 5 has the most positive impact on odor control, provides the redundancy of a second river crossing, provides flexibility to handle a wide range of future wastewater loading scenarios and/or effluent requirements and provides the most favorable environmental impact. The public is expected to offset the higher cost of Alternative 5 with positive odor control and avoidance of treatment in downtown Jefferson City. Alternative 5 is therefore the selected plan to be further developed with preliminary design. 4.7.3 Preliminary Design Selected Plan Alternative 5, a new Sequencing Batch Reactor plant designed for 11 mgd average flow and 60 mgd peak wet weather flow best meets the needs of the City of Jefferson for the 20 year planning period and potentially beyond. SBR technology allows wet and dry weather flows to be treated in the same system, eliminating the need for a separate wet-weather treatment system using different technology and at a different location. The large volume of the system and the programmable logic controller allow the flexibility to optimize treatment for a wide range of 4-24 I I I I I I I I I I I I I I I I influent conditions and/or effluent requirements. The system can adjust to future industrial or regulatory requirements without significant additional capital facilities. 4.7.3.1 Plant Layout The SBR system and new headworks will essentially replace the existing trickling filter system. So that the existing system can remain in operation as the new facilities are being constructed, the new headworks, screening, grit removal and SBR tanks will be constructed east of the existing facilities. The levee will pass very near the current entrance to the WPCF and prevent entry to the plant from Mokane Road. As part of the construction and in preparation for the new levee, the entrance to the WPCF will be moved to the north side of the plant property and a new administration building constructed near what is now the north west primary clarifier. The existing administration building will remain in service, housing sludge dewatering, maintenance, and facilities for the plant staff. Unneeded facilities such as the trickling filter towers and current headworks will be demolished. The recently upgraded sludge handling system has capacity for the increased loading from the new SBR system and will not be modified. The current secondary treatment area will become a landscaped area centered around the primary and secondary clarifier structures. The clarifiers will be partially filled to serve as ponds or fountains. The details of the landscaping will be determined during final design. Several possibilities will be considered from a conventional park like setting to perhaps plantings of native grasses. The new administration building will overlook the landscaped area. Figure 4-6 illustrates the preliminary layout of the WPCF as it would appear after the modifications have been completed. 4.7.3.2 Walnut Street Pump Station It is not cost effective to upgrade the current Walnut Street Pump Station to handle the 60 mgd design flow. A new pump station will be constructed near the existing station. The exact site has not been determined pending additional design analysis and negotiations on purchase of the needed additional property. Figure 4-7 illustrates the location of the current pump station and two potential locations for the new lift station. The foot print of the new 60 mgd pump station will not be significantly larger than for the current pump station. 4-25 _CJ ________________ _ ... ~ N RUNWAY PROTECTION ZONE NEW ADMINISTRATION BUILDING BLDG. RESTRICTION LINE -4-o,o. ~o~. '"'-11(- <oc ~~O..Jt 0,{' ( ~('( .... ,~< FERROUS CHLORIDE TANK BIOFILTER . FIGURE 4-6 CITY OF JEFFERSON WPCF 60 MGD PEAK FLOW SBR SYSTEM {AL lERNA TIVE 5) PREUMINARY LAYOUT RUNWAY PROPERTY LINE~ SCREENING/GRIT/ I BLOWER BLDG. ----------1---- SBR TANKS I I I NEW INFLUENT I FORCE MAIN 1 I ------- POTENTIAL NEW PUMP STATION - LOCATIONS · "" ", ....! W. HIGH ST.} ~ MISSOURI BLVD. FIGURE 4-7 CITY OF JEFFERSON -- MISSOURI RIVER EXISTING 30" FORCE MAIN EXISTING 24" FORCE MAIN WALNUT STREET PUMP STATION SITE -- I I I I I I I I I 4.7.3.3 Design Parameters Additional preliminary design detail for the new 60 mgd peak flow SBR system is provided below: Walnut Street Pump Station Wastewater will be pumped to the treatment facilities by a new submersible pump station located near the existing Walnut Street Pump Station. The new station will have five 15-mgd pumps. Two of the pumps will be equipped with variable speed drives; the other three units will operate as constant speed pumps. A second 30-inch diameter force main will be added under the Missouri River to the new plant headworks. This will provide redundancy to the existing 30- inch force main for dry weather flow. Both 30-inch force mains are needed to convey the 60 mgd peak flow. The damaged 24-inch diameter main under the river will be retired. Influent Screens At the new treatment plant, raw wastewater will be passed through fine mechanical screens with approximately 6-mm (~-inch) openings. Multiple screens, most likely three units, located in parallel channels will be used. The screens will be sized to handle the peak flow with one screen out of service. To save costs, reusing the existing Parkson Aquaguard screen will be considered. Screenings will be washed, concentrated, and conveyed to a dumpster. The screens, washer and dumpsters will be housed in a building to prevent cold-weather operating problems. Grit Chambers Screened wastewater will be degritted in two vortex-type grit chambers. Each chamber will be capable of handling up to 30 mgd flow, providing complete redundancy under dry-weather flow conditions. Normally, however, both units would be kept in operation at all times; both would need to operate during peak wet-weather flows. Each unit will be capable of being isolated by means of gates, and a bypass channel around the grit chambers will be provided. Collected grit will be pumped from each chamber to a grit classifier/dewatering unit and dumpster. The grit chambers will be located outdoors. Grit discharge lines will be heat traced and insulated as required for cold-weather protection. The grit classifier/dewatering unit and dumpster will be housed in a building to prevent cold weather operating problems. Flow Monitoring Influent flow will be measured with either a 60-inch or 72-inch Parshall flume, equipped with a suitable level sensor. The flume will have the ability to accurately measure the plant influent flow rate over the range of anticipated dry and wet weather flows. 4-28 I I I I I I I I I Sequencing Batch Reactor The preliminary-treated flow will then enter a channel that feeds four sequencing batch reactor basins. The four basins will be rectangular in shape and constructed with common interior walls to minimize costs. Each basin will have multiple inlet gates from the influent channel. These multiple gates will provide for operational redundancy, better influent distribution, and the ability to handle the wide range of flows occurring from dry to wet weather conditions. Fail-safe methods, such as weir walls, will be employed in the design to prevent bypassing of untreated flows in the event of mechanical or electrical failure of the gates. Consideration will also be given, during the final design, to configuring one of the basins for use as an emergency equalization basin, to be used in case of equipment or controls failure. Preliminary design criteria for the SBR system are summarized below: Design Parameter Value daily average flow 11 mgd maximum daily hydraulic flow 30mgd peak hourly flow 60mgd number of tanks 4 lbs oxygen supplied per lb BOD applied 1.25 lbs oxygen supplied per lb ammonia applied 4 .60 MLSS 3,000 mg/1 design F:M ratio 0.108 day"' cycles per basin per day 6 hydraulic retention time at low water level 15.5 hours lbs waste sludge per lb BODs applied 0.79 Aeration will be provided by diffused air, assisted if necessary by mechanical miXing. It is anticipated that positive displacement blowers will be used for aeration due to the range in operating pressures experienced with an SBR system. Blowers will be sized for a site elevation of 550 feet above MSL, and a temperature range of 0 to 100° F . High Water Lift Station Decanted liquid from the reactor basins will enter a common discharge channel and flow to the high-water lift station. Multiple decanters will be provided for redundancy and to handle the wide range of design flows. A new high-water lift station will be constructed, or the existing station will be modified with larger pumps and higher walls. The station will have the capacity to lift the entire 60 mgd flow under 1 00-year river flood conditions. The existing 54-inch outfall line will be used without modification. Sludge Handling Waste sludge will be pumped from the SBR units to the existing sludge thickeners. The existing sludge handling system will handle the sludge generated by the SBR system without modification except covers will be added to the thickeners for odor control. The existing odor control biofilter has sufficient vacuum and volume capacity to handle the thickeners. Supernatant from the thickeners as well as filtrate from the belt filter presses will be pumped, via a new pump station, back to the headworks downstream of the Parshall flume. 4-29 I I I I I I I I I I I Administration Building The existing administration building was built to accommodate the original primary treatment plant. Since that time secondary treatment has been added and the volume of wastewater treated has increased significantly. Additional building space is needed to handle increased staff and operating needs. A larger laboratory, control room and lead operators office are needed. Because access to the existing administration building from the south (the current main entrance) will be eliminated by the proposed Corps of Engineers flood control levee, it is appropriate to construct the additional office space on the north side of the WPCF near the new entrance. Office and staff functions will be split between the new and existing building. The new administration building will be located near the northwest primary clarifier as illustrated in Figure 4-6. The main components of the building are offices and laboratory for the plant operating staff and a conference area for use by plant personnel and also as an educational area for plant tours. The WPCF . staff encourages plant tours to educate student groups and the public at large to the functions of a wastewater treatment plant and the benefits to the environment. Tours can provide citizens an understanding as to the disposition of user charges. The convenient location with respect to the State Capitol might make the WPCF of interest to some out of town visitors as well. The new administration building will house a large conference room off a lobby large enough for groups to congregate. Offices for the Plant Superintendent and the lead operator will be provided as well as a larger laboratory area and control room. The preliminary layout of the administration building is illustrated in Figure 4-8. The building will overlook a landscaped area centered around the no longer needed primary and secondary clarifiers. This recycling of unneeded facilities will enhance the experience of visitors and will save the considerable cost of demolition. Maintenance and staff functions will remain in the existing building. The maintenance managers office will remain there, and the space made available by moving some functions to the new administration building will allow enlarging the lunch and locker areas while still providing a small conference room. The modifications to the existing building are illustrated in Figure 4-9. The sludge dewatering functions and maintenance area functions will not be modified other than removing the temporary extension of the lunch area into the maintenance area, opening up more maintenance space. Geotechnical Issues Geotechnical issues are always a concern when large structures are to be constructed. While borings and geotechnical evaluation are not part of this study effort, a very crude and brief review was given based on available soils information. Preliminary indications are that liquefaction, a potentially major cost factor, may not be significant. Other factors such as poor soil conditions and ground water may be able to be adequately addressed within the budget contingency of about $500,000. The cost of geotechnical requirements will not be known until foundation conditions are investigated early in the final design phase of the project. 4-30 -------------------- MEETING ROOM LOBBY FIGURE 4-8 CITY OF JEFFERSON 60 MGD PEAK FLOW SBR SYSTEM NEW ADMINISTRATION BUILDING PRELIMINARY LAYOUT L./\llOR/\TORY ----------------·--- SLUDGE HANDLING (} D MAINTENANCE RESTROOM/ SHOWERS FIGURE 4-9 CITY OF JEFFERSON (} LUNCH ROOM MAINTENANCE OFFICE 60 MGD PEAK FLOW SBR SYSTEM MODIFICATIONS TO EXISTING OFFICE AREA PRELIMINARY LAYOUT GARAGE TOOL ROOM I I I I I I I I I I I I I I I I I I I 4. 7.4 Environmental Assessment The immediate and long term environmental impacts of the construction and other issues needed to implement the 60 mgd peak flow SBR system are not expected to be significant. The new facilities at the WPCF site will be constructed in what is currently farm land, but land that is destined to be developed when the new Corps of Engineers flood control levee eliminates the flood potential. The Walnut Street Pump Station area is heavily disturbed, being adjacent to active railroad tracks. The land required to construct the new facilities is relatively small and adjacent to already active sites, so minimum impact on fish and wildlife is expected. Appropriate measures will be taken during construction to minimize soil erosion. There will be temporary construction disturbances related to dust, noise and aesthetics. These will not be long term and should end with construction. No wetlands or environmentally sensitive areas are · known to be associated with the construction. No secondary impacts such as increased property values or induced population growth are anticipated. The completed construction should improve aesthetics by essentially eliminating odor from the secondary treatment process and providing a new landscaped area. Because WPCF effluent limits will decrease from a monthly average of 45 mg/1 BOD and 45 mg/1 suspended solids to 30 mg/1 for both BOD and suspended solids, and because the actual eftluent quality is expected to be significantly below these limits, there will be a significant positive impact on the Missouri River. Also, wet weather flows will receive secondary treatment. In summary, the net environmental impact of the proposed WPCF improvements is strongly positive. 4-33 I I I I I I I I I I I I I I I I I I SECTIONS PROJECT IMPLEMENTATION 5.1 Cost Impacts and Financing Cost is a major consideration in implementing the selected Water Pollution Control Facility (WPCF) Improvements. Costs to be considered include both the capital cost to construct as well as costs associated with operating the new facilities. The impact of the new construction on current operating costs is essentially neutral. The sequencing batch reactor system (SBR) with three major unit operations (screening, grit removal and SBR) replaces the trickling filter system with five major unit operations (screening, grit removal, primary clarifiers, trickling filters, secondary clarifiers) and more complex sludge and scum pumping systems. The maintenance prone Walnut Street Pump Station will be replaced by an efficient new pump station. The SBR process should produce less waste sludge with associated lower sludge handling costs but will have higher power costs. The City currently has two unfilled wastewater treatment operating positions. It is believed that at least one of these positions can be eliminated because of the efficiencies of the new system and equipment. The net result is that operating costs will not differ significantly from current costs Construction financing for the capital portion of the Water Pollution Control Facility Improvements will be through the Clean Water State Revolving Fund administered by the Missouri Department of Natural Resources Division of Environmental Quality. Bonds are sold and as bond proceeds are spent, the Revolving Fund puts an amount equal to 70 percent of the bond proceeds into a reserve fund. Interest from this fund is used to subsidize interest on the bonds. The subsidy allows the City an interest rate about half the normal municipal rate. As discussed in Part 2.6.4 of Section 2, it is intended for the WPCF to treat wet weather flows for all but the most intense storms. The current wet weather flow exceeds the design capacity of new SBR system because of infiltration and inflow (Ill) into the sewer system. The III must be reduced sufficiently for the wet weather flow to be no greater than the design capacity of the SBR system. To efficiently address the III problems, the sewer system must first be studied to determine the sources of the III and then repaired as indicated by the study. Implementation of the WPCF Improvements will, therefore, include construction of the new SBR treatment system and Walnut Street Pump Station as well as an III correction component. The estimated $22,710,000 cost of the selected 60 mgd Sequencing Batch Reactor system plus closing costs will be funded using a 20 year uniform annual payment loan from the Clean Water State Revolving Fund. The III portion includes annual funding for a fifteen year study program and also an annual budget allocation for repairing the problems identified by the study. The additional annual revenue needed to fund the WPCF Improvements is therefore: Cost Component Annual Cost (2000 dollars) Payment to Retire WPCF Construction Loan (fixed annual payment for 20 years) $1,488,000 Study of Sewer System III Problems (15 year program) 263,000 Allocation for 20 years to fund Improvements Identified in Sewer Master Plan 500,000 Additional Annual Cost $2,251,000 I I I I I I I I I I I I I I I I I I I The needed additional revenue reduced by current surplus revenue and reserves from the City Wastewater Enterprise Fund will require an average annual increase in revenue from user charges over the 20 year study period of about $916,000 a year. This will be distributed among users by continuing the current user charge structures and maintaining the same percentages between City users and outside the City users. Commercial and industrial users will receive the same percentage increase as residential users. The monthly user charge for average City and outside the City residential users will increase as follows: User Charge Component Current Rate Proposed Rate (Since November 1, 1986) (Begin July l, 2001) City Residential User Fixed Monthly Minimum Charge $3.33 $4.16 Outside City Residential User Fixed Monthly Minimum $9.99 $12.47 Volume Charge per 100 cu. ft . $1.055 $1.32 It is anticipated as this Facility Plan is prepared that rate increase will begin in July 2001; however, the City may choose to modify this schedule somewhat. Rates have not been increased for over 1 0 years. The new rate is still less than the average for cities in the classification of the City of Jefferson, according to a survey by Raftelis Financial Consultants. At the new rates, a City customer using 900 cubic feet a month would pay $16.04 per month compared to an average of about $19.00 a month for the same usage for the 73 systems in the survey that were grouped with the City of Jefferson. 5.2 Schedule As discussed previously in this Facility Plan, the WPCF is currently at design capacity. Little additional flow or loading can be accepted without jeopardizing eftluent quality. Implementation of the WPCF improvements needs to move expeditiously. The schedule listed in Table 5-1 shows key dates that should be met to move the WPCF toward design, construction and operation. S-2 I I I I I I I I I I I I I I I I I I I TABLES-I WPCF IMPLEMENTATION SCHEDULE KEY DATES Facility Plan submitted for DNR review April 2000 Public meetings May 2000 DNR approves Facility Plan and issues FNSI June 2000 City begins acquiring needed property and easements June 2000 Begin WPCF Improvement design/bid documents June 2000 50% WPCF design/bid documents submitted to DNR October 2000 City of Jefferson residents approve Revolving Fund bond issue November 2000 Draft User Charge and Sewer Use Ordinances submitted to DNR November 2000 Complete WPCF design/bid documents submitted to DNR January 2001 Construction permit application and fee submitted to DNR January 2001 City issues assurance of property/easement acquisition with DNR January 2001 Bid documents and ordinance issues resolved with DNR February 2001 Bid documents advertised for bid March 2001 State Revolving Fund loan closing April 2001 Bids for WPCF construction received April2001 Contract for WPCF construction awarded and notice to proceed June 2001 Draft Plan of Operation & O&M Manual submitted to DNR December 2001 Final Plan of Operation & O&M Manual approved by DNR August 2002 WPCF construction complete, SBR plant goes into operation November 2002 5-3 I I I I I I I APPENDIX I COST BACK-UP I I I I I I I I I I I I I I I I I I I I I I I I I I Alternative 1 • 25 mgd peak upgraded trickling filter system • 35 mgd peak wet weather treatment at Walnut Pump Station A-2 I I I I I I I I I I I I I I I I I Cost Estimate -Alternative No. 1 Item Quantity Unit Price Headworks Demolition of existing 1 ! LS New 1 LS Settled Sewage Pump Station Pumps & modifications 2 ea $100 ,000 Trickling Filter One New Tank 1 LS Two Existing Tanks 1 LS Odor Control 1 LS Final Clarifiers New Tanks 2 ea $725 ,000 Sludge Pumps & Piping 2 ea $75 ,000 High Water Pump Station Pumps & modifications 3 ea $100 ,000 Yard Piping 1 LS Wet Weather Treatment Unit 1 LS Walnut Pump Station 1 LS Repairs to Existing Facilities 1 LS Building Rehab I Remodel 1 LS Electrical and I&C Work 1 LS Total Total $120,000 $1 ,460 ,000 $200 ,000 $1 ,000,000 $1,220 ,000 $1 ,120,000 $1 ,450,000 $150,000 $300,000 $890,000 $4,700,000 $3,200 ,000 $1,000,000 $750,000 $1,300,000 $18,860,000 ----- I I I Alternative 1 Personnel Services I Superintendent see current total Lead Operator see current total Operator see current total Operator see current total I Laboratory Manager see current total Maintenance Head see current total Mechanic see current total Mechanic see current total Mechanic see current total Maintenance see current total Maintenance see current total I Open see current total Open see current total Current Staff Total (incl OT & seasonal) $410,000 I Additional Staff $30,000 Subtotal $440,000 Fringes 34.00% $149,600 Total Personnel Services $589,600 I Contractual Services Trash $10,000 I Other $10,000 Total Contractual Services $20,000 I Materials & Supplies Chemicals -sludge polymer $61,101 I -sludge lime $73,321 -Odor control $10,000 -Miscellaneous $25,000 -Actiflo sand $255 I -Actiflo coagulant $38,250 -Actiflo polymer $3,825 $211,752 Other (fuel, oils, etc ... ) $25,000 I Total Materials & Supplies $236,752 Utilities Other $25,000 Electric Power (see sheet 2) $229,642 Total Utilities $254,642 I Repairs & Maintenance Buildings and Grounds $30,000 Equipment $75,000 I Vehides $50,000 Pumping Systems $50,000 Other $10,000 I Total Repairs & Maintenance $215,000 Total Annual O&M Cost $1,315,994 I I I I I I I I I I I I I I I Alternative 1 Power Unit Operation hp factor kwh/year Annual Cost Walnut Pump Station 1,074,264 $59,085 Actiflo 100 0.15 124,830 $6,866 Inlet Fine Screening 3 1.00 24,966 $1,373 Grit Removal 3 1.00 24,966 $1,373 Grit Pumping I Classifying 15 0.50 62,415 $3,433 Pre aeration 10 1.00 83,220 $4,577 Primary Settling 4 1.00 33,288 $1,831 Primary Sludge/Scum Pumping 20 0.50 83,220 $4,577 Settled Sewage Pump Station 146 1.25 1,518,765 $83,532 Trickling Filters 3 1.00 24,966 $1,373 Trickling Filter Ventilation & Odor Control 25 1.00 208,050 $11,443 SBR n/a Final Clarifiers 4 1.00 33,288 $1,831 Secondary Sludge/Scum Pumping 5 0.50 20,805 $1,144 Plant Water Pumping 30 0 .25 62,4 15 $3,433 High Water Pump Station 44 0.15 54,925 $3,021 Sludge Thickening/Pumping 10 1.00 83,220 $4,577 Sludge Storage 30 1.00 249,660 $13,731 Sludge Dewatering/Stabilization 100 0 .25 208 ,050 $11,443 Site Ughting & Miscellaneous NIA 200,000 $11,000 4,175,313 $229,642 kwH calculation includes motor and drive efficiency corrections, and a power factor correction, so that 1 hp-hr requires approx 0.95 kw-hr. Factor adjusts for non-continuous operation and/or recycle flows. Unit cost of electricity (dollars per KwHr) $0.055 I I I I I I I I I Alternative 2 • 25 mgd peak upgraded trickling filter system • 35 mgd peak wet weather treatment at WPCF site • New 30-inch force main A-6 I I I I I I I I I I I Cost Estimate -Alternative No. 2 Item Quantity Unit Price Headworks Demolition of existing 1 LS New 1 LS Settled Sewage Pump Station Pumps & modifications 2 ea $100 ,000 Trickling Filter One New Tank 1 I LS Two Existing Tanks 1 LS Odor Control 1 i LS Final Clarifiers New Tanks 2 ea $725,000 Sludge Pumps & Piping 2 ea $75,000 High Water Pump Station New station 1 LS Yard Piping 1 LS Wet Weather Treatment Unit 1 LS Walnut Pump Station 1 LS New 30-inch Force Main 1 LS Repairs to Existing Facilities 1 LS Building Rehab I Remodel 1 LS Electrical and I&C Work 1 LS Total Total $120,000 $2,480,000 $200,000 $1,000,000 $1,220 ,000 $1,120,000 $1 ,450,000 $150,000 $1,190,000 $800,000 $4,700,000 $3,200,000 $2,300,000 $1,000,000 $750,000 $1,300,000 $22,980,000 I I I Alternative 2 Personnel Services I Superintendent see current total Lead Operator see current total Operator see current total Operator see current total Laboratory Manager see current total Maintenance Head see current total Mechanic see current total I Mechanic see current total Mechanic see current total Maintenance see current total Maintenance see current total Open see current total Open see current total Current Staff Total (ind OT & seasonal) $410,000 I Additional Staff $30,000 Subtotal $440,000 Fringes 34.00% $149,600 Total Personnel Services $589,600 Contractual Services Trash $10,000 Other $10,000 Total Contractual Services $20,000 I Materials & Supplies Chemicals • sludge polymer $61,101 I • sludge lime $73,321 • Odor control $10,000 • Miscellaneous $25,000 • Actiflo sand $255 • Actiflo coagulant $38,250 • Actiflo polymer $3,825 $211,752 Other (fuel, oils, etc ... ) $25,000 I Total Materials & Supplies $236,752 Utilities I Other $25,000 Electric Power (see sheet 2) $232,617 Total Utilities $257,617 Repairs & Maintenance Buildings and Grounds $30,000 Equipment $75,000 I Vehides $50,000 Pumping Systems $50,000 Other $10,000 I Total Repairs & Maintenance $215,000 Total Annual O&M Cost $1 ,318,970 I I I I I I I I I I I I Alternative 2 Power Unit Operation hp factor kwh/year Annual Cost Walnut Pump Station 1,074,264 $59,085 Aditio 100 0 .15 124,830 $6,866 Inlet Fine Screening 6 1.00 49,932 $2,746 Grit Removal 4 1.00 33,288 $1,831 Grit Pumping I Classifying 20 0.50 83,220 $4,577 Preaeration 10 1.00 83,220 $4,577 Primary Settling 4 1.00 33,288 $1,831 Primary Sludge/Scum Pumping 20 0.50 83,220 $4,577 Settled Sewage Pump Station 146 1.25 1,518,765 $83,532 Trickling Filters 3 1.00 24,966 $1,373 Trickling Filter Ventilation & Odor Control 25 1.00 208,050 $11,443 SBR n/a Final Clarifiers 4 1.00 33,288 $1 ,831 Secondary Sludge/Scum Pumping 5 0.50 20,805 $1 ,144 Plant Water Pumping 30 0 .25 62,415 $3,433 High Water Pump Station 44 0 .15 54,925 $3,021 Sludge Thickening/Pumping 10 1.00 83,220 $4,577 Sludge Storage 30 1.00 249,660 $13,731 Sludge Dewatering/Stabilization 100 0.25 208,050 $11,443 Site Ughting & Miscellaneous N/A 200,000 $11 ,000 4 ,229,406 $232,617 kwH calculation indudes motor and drive efficiency corrections, and a power factor correction, so that 1 hp-hr requires approx 0.95 kw-hr. Factor adjusts for non-continuous operation and/or recyde flows. Unit cost of electricity (dollars per KwHr} $0.055 I I I I I I I I I I I I I Alternative 3 • 30 mgd peak SBR • 30 mgd wet weather treatment Walnut Pump Station A-10 I I I I I I I I I I Cost Estimate -Alternative No. 3 Item Quantity Unit Price Demolition of Existing Plant 1 LS Headworks I New 1 LS SBRs !Tankage 1 LS I Equipment & mechanical 1 LS High Water Pump Station I Pumps & modifications 3 ea $100,000 Wet Weather Treatment Unit 1 LS Walnut Pump Station 1 LS Yard Piping 1 LS Repairs to Existing Facilities 1 LS Building Rehab I Remodel 1 LS Electrical and I&C Work 1 LS Total Total $1,000,000 $1,630,000 $4,900,000 $3,500,000 $300,000 $4,300,000 $3,200,000 $880,000 $100,000 $750,000 $2,000,000 $22,560,000 I Alternative 3 Personnel Services I Superintendent see current total Lead Operator see current total Operator see current total Operator see current total I Laboratory Manager see current total Maintenance Head see current total Mechanic see current total I Mechanic see current total Mechanic see current total Maintenance see current total Maintenance see current total I Open see current total Open see current total Current Staff Total (incl OT & seasonal) $410,000 I Additional Staff $0 Subtotal $410,000 Fringes 34.00% $139,400 Total Personnel Services $549,400 I Contractual Services Trash $10,000 I Other $10,000 Total Contractual Services $20,000 I Materials & Supplies Chemicals -sludge polymer $41,665 I -sludge lime $49,998 -Odor control $1,000 -Miscellaneous $25,000 -Actiflo sand $225 I -Actiflo coagulant $33,000 -Actiflo polymer $3,300 $154,187 Other (fuel, oils, etc •.. ) $25,000 I Total Materials & Supplies $179,187 Utilities I Other $25,000 Electric Power (see sheet 2) $406,726 Total Utilities $431,726 I Repairs & Maintenance Buildings and Grounds $30,000 Equipment $75,000 I Vehicles $50,000 Pumping Systems $50,000 Other $10,000 Total Repairs & Maintenance $215,000 Total Annual O&M Cost $1,395,314 I I I I I I I I I I I I I I I I I I I Alternative 3 Power Unit Operation hp factor kwh/year Annual Cost Walnut Pump Station 1,074,264 $59,085 Actiflo 100 0 .15 124,830 $6,866 Inlet Fine Screening 3 1 .00 24,966 $1,373 Grit Removal 4 1 .00 33,288 $1,831 Grit Pumping I Classifying 15 0.50 62,415 $3,433 Preaeration 10 1.00 83,220 $4,577 Primary Settling 0 1.00 0 $0 Primary Sludge/Scum Pumping 0 0.50 0 $0 Settled Sewage Pump Station 0 1.25 0 $0 Trickling Filters 0 1.00 0 $0 Trickling Filter Ventilation & Odor Control 0 1.00 0 $0 SBR 0 5,317,685 $292,473 Final Clarifiers 0 1.00 0 $0 Secondary Sludge/Scum Pumping 0 0.50 0 $0 Plant Water Pumping 30 0.25 62,415 $3,433 High Water Pump Station 50 0.15 62,415 $3,433 Sludge Thickening/Pumping 10 1.00 83,220 $4,577 Sludge Storage 30 0.50 124,830 $6,866 Sludge Dewatering/Stabilization 100 0.17 141,474 $7,781 Site Lighting & Miscellaneous NIA 200,000 $11,000 7,395,022 $406,726 kwH calculation includes motor and drive efficiency corrections, and a power factor correction, so that 1 hp-hr requires approx 0.95 kw-hr. Factor adjusts for non-continuous operation and/or recycle flows. Unit cost of electricity (dollars per KwHr) $0.055 I I I I I I I I I I I I I I I I I I I Alternative 4 • 30 mgd peak SBR • 30 mgd wet weather treatment using existing clarifiers • New 30-inch force main A-14 I I I I I I I I I I I I I I I I I I Cost Estimate -Alternative No. 4 Item Quantity Unit Price Partial Demolition of Existing Plant 1 LS Headworks !New 1 i LS SBRs !Tankage 1 I LS l Equipment & mechanical 1 LS Walnut Pump Station 1 LS New 30-inch Force Main 1 i LS High Water Pump Station lNew station 1 LS Yard Piping 1 LS Repairs to Existing Facilities 1 LS Building Rehab I Remodel 1 LS Electrical and I&C Work 1 LS Total Total $530,000 $2,480,000 $4,900,000 $3,500,000 $3,200,000 $2,300,000 $1,190,000 $1,300,000 $500,000 $750,000 $2,000,000 $22,650,000 I I I Alternative 4 Personnel Services I Superintendent see current total Lead Operator see current total Operator see current total Operator see current total I Laboratory Manager see current total Maintenance Head see current total Mechanic see current total I Mechanic see current total Mechanic see current total Maintenance see current total Maintenance see current total I Open see current total Open see current total Current Staff Total (ind OT & seasonal) $410,000 I Additional Staff $0 Subtotal $410,000 Fringes 34.00% $139,400 Total Personnel Services $549,400 I Contractual Services Trash $10,000 I Other $10,000 Total Contractual Services $20,000 I Materials & Supplies Chemicals -sludge polymer $41,665 I -sludge lime $49,998 -Odor control $0 -Miscellaneous $25,000 -Actiflo sand $0 I -Actiflo coagulant $0 -Actiflo polymer $0 $116,662 Other (fuel, oils, etc ... ) $25,000 I Total Materials & Supplies $141,662 Utilities I Other $25,000 Electric Power (see sheet 2) $403,785 Total Utilities $428,785 I Repairs & Maintenance Buildings and Grounds $30,000 Equipment $75,000 I Vehides $50,000 Pumping Systems $50,000 Other $10,000 I Total Repairs & Maintenance $215,000 Total Annual O&M Cost $1,354,848 I I I I I I I I I I I I I I I I I I I I I Altemative4 Power Unit Operation hp factor kwh/year Annual Cost Walnut Pump Station 1,074,264 $59,085 Actiflo 0 0.15 0 $0 Inlet Fine Screening 6 1.00 49,932 $2,746 Grit Removal 4 1.00 33,288 $1,831 Grit Pumping I Classifying 20 0 .50 83,220 $4,577 Preaeration 10 1.00 83,220 $4,577 Primary Settling 4 0.15 4,993 $275 Primary Sludge/Scum Pumping 20 0.08 12,483 $687 Settled Sewage Pump Station 0 1.25 0 $0 Trickling Filters 0 1.00 0 $0 Trickling Filter Ventilation & Odor Control 0 1.00 0 $0 SBR 0 5,317,685 $292,473 Final Clarifiers 4 0.15 4,993 $275 Secondary Sludge/Scum Pumping 5 0.08 3,121 $172 Plant Water Pumping 30 0.25 62,415 $3,433 High Water Pump Station 50 0 .15 62,415 $3,433 Sludge Thickening/Pumping 10 1.00 83,220 $4,577 Sludge Storage 30 0.50 124,830 $6,866 Sludge Dewatering/Stabilization 100 0 .17 141,474 $7,781 Site Ughting & Miscellaneous N/A 200,000 $11,000 7 ,341,553 $403,785 kwH calculation includes motor and drive efficiency corrections, and a power factor correction, so that 1 hp-hr requires approx 0.95 kw-hr. Factor adjusts for non-continuous operation and/or recycle ftows. Unit cost of electricity (dollars per KwHr) $0.055 I I I I I I I I I I I I I I I I I I Alternative 5 • 60 mgd peak SBR • New 30-inch force main A-18 I I I I I I I I I I I I I I I I I Cost Estimate -Alternative No. 5 Item Quantity Unit Price Demolition of Existing Plant 1 LS Headworks l New 1 LS SBRs !Tankage 1 ! LS I Equipment & mechanical 1 l LS High Water Pump Station I New station 1 LS Walnut Pump Station 1 LS New 30-inch Force Main 1 LS Yard Piping 1 LS Repairs to Existing Facilities 1 LS Building Rehab I Remodel 1 LS Electrical and I&C Work 1 LS Total Total $1,000,000 $2,480,000 $4,900,000 $3,900,000 $1,190,000 $3,200,000 $2,300,000 $890,000 $100,000 $750,000 $2,000,000 $22,710,000 Alternative 5 Personnel Services I Superintendent see current total Lead Operator see current total Operator see current total Operator see current total I Laboratory Manager see current total Maintenance Head see current total Mechanic see current total I Mechanic see current total Mechanic see current total Maintenance see current total Maintenance see current total I Open see current total Open see current total Current Staff Total (incl OT & seasonal) $410,000 Additional Staff -$30,000 Subtotal $380,000 Fringes 34.00% $129,200 Total Personnel Services $509,200 I Contractual Services Trash $10,000 I Other $10,000 Total Contractual Services $26,006 I Materials & Supplies Chemicals -sludge polymer $41,665 I -sludge lime $49,998 -Odor control $0 -Miscellaneous $25,000 -Actiflo sand $0 I -Actiflo coagulant $0 -Actiflo polymer $0 $116,662 Other (fuel, oils, etc ... ) $25,000 I Total Materials & Supplies $141,662 Utilities I Other $25,000 Electric Power (see sheet 2) $409,244 Total Utilities $434,244 I Repairs & Maintenance Buildings and Grounds $30,000 Equipment $75,000 I Vehicles $50,000 Pumping Systems $50,000 Other $10,000 I Total Repairs & Maintenance $215,000 Total Annual O&M Cost $1,320,106 I I I I I I I I I I .I I I Alternative 5 Power Unit Operation hp factor kwh/year Annual Cost Walnut Pump Station 1,074,264 $59,085 Actiflo 100 0 .15 124,830 $6,866 Inlet Fine Screening 6 1.00 49,932 $2,746 Grit Removal 4 1.00 33,288 $1 ,831 Grit Pumping I Classifying 20 0 .50 83,220 $4,577 Preaeration 10 1.00 83,220 $4,577 Primary Settling 0 1.00 0 $0 Primary Sludge/Scum Pumping 0 0 .50 0 $0 Settled Sewage Pump Station 0 1.25 0 $0 Trickling Filters 0 1.00 0 $0 Trickling Filter Ventilation & Odor Control 0 1.00 0 $0 SBR 0 5,317,685 $292,473 Final Clarifiers 0 1.00 0 $0 Secondary Sludge/Scum Pumping 0 0 .50 0 $0 Plant Water Pumping 30 0.25 62,415 $3,433 High Water Pump Station 50 0.15 62,415 $3,433 Sludge Thickening/Pumping 10 1.00 83,220 $4,577 Sludge Storage 30 0.50 124,830 $6,866 Sludge Dewatering/Stabilization 100 0.17 141,474 $7,781 Site Lighting & Miscellaneous N/A 200,000 $11,000 7,440,793 $409,244 kwH calculation includes motor and drive efficiency corrections , and a power factor correction, so that 1 hp-hr requires approx 0.95 kw-hr. Factor adjusts for non-continuous operation and/or recycle flows. Unit cost of electricity (dollars per KwHr) $0.055