Akron Water Pollution Control Station No Feasible Alternative

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Akron Water Pollution Control No Feasible Alternative (NFA) ABBREVIATIONS/SYMBOLS (con’t) MLSS mixed liquor suspended solids mm. millimeter NFA No Feasible Alternative NH3-N ammonia nitrogen NPDES National Pollutant Discharge Eliminiation System No. number NSI Northside Interceptor OCI Ohio Canal Interceptor OEPA Ohio Environmental Protection Agency O&M operation and maintenance P phosphorous PDF peak daily flow / per % percent PFD process flow diagram psi pounds per square inch PST primary settling tank RAS return activated slugde RBC rotating biological contactor R/W right-of-way SBC submergeged biological contactor scfm standard cubic feet per minute sf square feet SOR surface overflow rate SRT storm retention tank SSO sanitary sewer overflow STS secondary treatment system SWD side water depth TMDL total maximum daily load TSS total suspended solids USEPA United States Environmental Protection Agency WAS waste activated sludge WEF Water Environment Federation WERF Water Environment Research Foundation WPCS Water Pollution Control Station Page vi
SECTION 1 EXECUTIVE SUMMARY The purpose of the Akron Water Pollution Control Station (WPCS) No Feasible Alternative (NFA) Report is to incorporate the City of Akron’s prior NFAs into one report, as well as to evaluate and update the NFA. This NFA was performed in accordance with Section II.C.7 of U.S. EPA’s 1994 Combined Sewer Overflow Control Policy (the CSO Policy), and is an amendment to the City of Akron’s LTCP. The following elements of Section II.C.7. of the CSO Policy are addressed within the referenced sections of this Report. 1. Justification for the cut-off point at which the flow will be diverted from secondary. This narrative is presented in Sections 3.3 through 3.6. 2. A cost-benefit analysis demonstrating whether providing additional treatment at the plant is more beneficial than other alternatives including storage and pump back for secondary treatment, sewer separation, or satellite treatment. This analysis is presented in Sections 5.1 and 5.2, as well as represented for sewer separation in Section 4.3 and for satellite treatment in Section 4.4. 3. Evidence that the system has been designed to meet secondary limits for flow greater than the peak dry weather flow plus an appropriate quantity of wet weather flow is generally found in Section 3. 4. Evidence that it is technically or financially infeasible to provide secondary treatment at the existing facilities for greater amounts of wet weather flow is presented in Section 5. 5. Consideration of enhanced primary treatment (e.g., chemical addition) and non-biological secondary treatment is given within the Secondary Treatment Alternatives, Sections 4.2 and 4.6. 6. Consideration of possible adverse effects resulting from the bypass is included in Table 5.3. Section 2 of this Report provides a brief summary of City of Akron’s sewage collection and wastewater treatment system infrastructure planning and improvements as they relate to a continual effort to improve service and water quality. The CSO Policies pertaining to this NFA Report are also reviewed. The existing capabilities of the Akron WPCS are summarized in Section 3. Process and hydraulic capacities are established. This section also summarizes the results from prior stress tests and discusses the results of an additional stress test that was performed in 2006. The WPCS has a firm peak flow capacity of 210 MGD through preliminary and primary treatment systems. The Secondary Treatment system is limited to 110 MGD without further stress testing, process modeling and constructed improvements. Primary effluent quality wastewater flow above 110 MGD, occurring during wet weather events, is currently routed directly to the disinfection facility for combining with secondary effluent prior to chlorination/dechlorination, and discharges to the Cuyahoga River. Section 4 presents an evaluation of alternatives to alter and/or improve the Akron wastewater collection and treatment systems. Collection system alternatives developed in previously submitted planning documents are summarized and re-presented with updated costs. Additional Secondary Treatment alternatives, including secondary bypass high rate clarification systems, are developed, screened and evaluated. Page 1-1
Page 1 and 2: City of Akron Akron Water Pollution
Page 3 and 4: Akron Water Pollution Control Stati
Page 5 and 6: TABLES Akron Water Pollution Contro
Page 7: Akron Water Pollution Control No Fe
Page 11 and 12: SECTION 2 INTRODUCTION 2.1. NFA Rep
Page 13 and 14: 150 MGD due to their hydraulics. Th
Page 15 and 16: SECTION 3 EXISTING WPCS CAPABILITIE
Page 17 and 18: Month Raw Influent Flow Table 3-2 2
Page 19 and 20: Table 3-3 (con’t) Akron WPCS Exis
Page 21 and 22: 3.3. Secondary Treatment Limitation
Page 23 and 24: The hydraulic evaluation prepared a
Page 25 and 26: • final settling tank influent di
Page 27 and 28: • The simulated 120 MGD test leve
Page 29 and 30: Table 3-4 Secondary Treatment Facil
Page 33 and 34: SECTION 4 EVALUATION OF ALTERNATIVE
Page 35 and 36: 5. Summarize high-rate treatment pi
Page 37 and 38: Table 4-4 Akron WPCS Average Influe
Page 39 and 40: For these reasons the Group 2 Alter
Page 41 and 42: effluent pumping and fine screening
Page 43 and 44: The 3-year solids production rate a
Page 45 and 46: The 120 MGD alternative requires fu
Page 47 and 48: The City of Akron has previously pe
Page 49 and 50: Type of Cost Capital O&M Present Wo
Page 51 and 52: ed), exhaust fans, and associated d
Page 53 and 54: 6. For each Rack, the minimum perfo
Page 55 and 56: Rack # CBOD Present Worth ($) Table
Page 57 and 58: CSO Control Technology Tunnels Tabl
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• 20 MG of storage located near p
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ecirculated back to the reactor tan
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Table 4-13 HRT Design/Operational C
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is its chemical coagulant and polym
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Secondary Treatment Alternative "No
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Final Settling Tanks Qp = 110 MGD 1
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High Rate Treatment Qp = 110 MGD (B
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Membrane Filters Qp = 110 MGD (Bypa
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Modify Aeration Basins with MBR Qp
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10 MG Storage 10 MG Storage 10 MG S
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SECTION 5 ALTERNATIVE SCREENING 5.1
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For the cost and non-cost reasons n
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enefit analysis, it is recommended
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5.3. Summary of Recommended Alterna
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SECTION 7 BIBLIOGRAPHY 1. The Akron
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ATTORNEY/CLIENT PRIVILEGE ATTORNEY
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Akron Water Pollution Control Stati
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cfs cubic feet per second DO dissol
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SECTION 2 INTRODUCTION The Akron Wa
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4. The Stress Test proceeded as fol
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SECTION 4 STRESS TEST TRIALS 4.1. S
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4.2. Simulated 144 MGD Test The pro
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Based on observations and results o
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phosphorus. The apparent ineffectiv
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Concentration (mg/l) 10.0 9.0 8.0 7
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TABLE 4-2 AKRON WPCS STRESS TEST Si
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Page 113 and 114:
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SECTION 5 CONCLUSIONS AND RECOMMEND
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Appendix A City-Provided WPCS Data
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AKRON WPCS 2006 120 MGD STRESS TEST
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20-Nov-06 # 1 ML # 2 ML # 1 RAS # 2
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20-Nov-06 # 1 ML # 2 ML # 1 RAS # 2
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20-Nov-06 # 1 ML # 2 ML # 1 RAS # 2
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AKRON WPC 2006 144 MGD STRESS TEST
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28-Nov-06 # 1 ML # 2 ML # 1 RAS # 2
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28-Nov-06 # 1 ML # 2 ML # 1 RAS # 2
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28-Nov-06 # 1 ML # 2 ML # 1 RAS # 2
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AKRON WPC 2006 120/132 MGD STRESS T
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5-Dec-06 # 1 ML # 2 ML # 1 RAS # 2
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5-Dec-06 # 1 ML # 2 ML # 1 RAS # 2
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Cost Development Guidelines Appendi
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ALTERNATIVE 1C - 10 MGD SINGLE UNIT
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ALTERNATIVE 1E - 100 MGD UNITS PROB
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APPENDIX C Secondary Treatment Pres
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annually. The effort for the 40 MG
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Akron WPCS NFA Alternative 1 -Secon
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Akron WPCS NFA Alternative 1 -Secon
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Akron WPCS NFA Alternative 1A 20 MG
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Akron WPCS NFA Alternative 1A 20 MG
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Akron WPCS NFA Alternative 1B 40 MG
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Akron WPCS NFA Alternative 1B 40 MG
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Akron WPCS NFA Alternative 1C 10 MG
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Akron WPCS NFA Alternative 1C 10 MG
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Akron WPCS NFA Alternative 1D 50 MG
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Akron WPCS NFA Alternative 1D 50 MG
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Akron WPCS NFA Alternative 1E 100 M
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Akron WPCS NFA Alternative 1E 100 M
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Akron WPCS NFA Alternative 1F 150 M
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Akron WPCS NFA Alternative 1F 150 M
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Akron Water Pollution Control Station No Feasible Alternative

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