Integrated Long Term Control Plan Targeted Inflow Reduction for CSO Control. OWEA Conference June 29, 2016

Transcription

1 Integrated Long Term Control Plan Targeted Inflow Reduction for CSO Control OWEA Conference June 29, 2016

2 WWTP Average Daily Flow 6 MGD Peak Flow (Primary Only) 12 MGD Collection System 123 Miles (8 to 54 ) 74 Miles of Combined Sewers 49 Miles of Sanitary Sewers 2,400 Manholes 25 Pump Stations 44 Original CSO s 28 Remaining CSO s 3 River Siphons

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5 Original LTCP Prepared in 1998 LTCP Addendum Prepared in 2003 $48.8M for 20 Years Sewer Separation / CSO Elimination Consent Order Approved in March 2010 Early Action Separation Projects ( ) Groups 1 6

6 Red = Closed Overflow (16) Black = Active Overflow (28)

7 Completed Sewer Separation Groups % Higher than Original LTCP Estimates First 6 Groups - $24.8M Actual / $13.4M Planned Private Property Clean Water Disconnection Costs 490% Higher than Original LTCP Estimates First 6 Groups - $3.8M Actual / $780k Planned Projected Cost Increased to $118M to Complete Sewer Separation Program Unaffordable

8 Coordinated with Ohio EPA to Evaluate Program Meetings with Ohio EPA and Attorney General s Office Reviewed feasibility of Original LTCP Evaluated CSO Control vs. Elimination Consent Order Modification Approved September, Year extension to prepare a new plan to control CSO s LTCP Update

9 LTCP Approach System Characterization Flow Monitoring River Water Intrusion Evaluation Hydraulic Modeling Alternative Screening and Analysis Inflow Reduction Analysis Financial Affordability Analysis Alternative Selection Cost Estimate Development

10 US EPA CSO Control Policy Guidance Decision Making Process Adaptive Management Strategy Data Driven Approach Technical Review Committee Executive Committee US EPA Integrated Planning Approach MS4 WWTP CSO/SSO

11 Technical Committee Aids in Data Gathering and Analysis Consists of Collection System, Engineering, Construction, WWTP Operations, and Stormwater Staff Executive Committee Decision Making Team Analyze Recommendations Made by the Technical Committee Consists of Members with Engineering, Economic, Environmental, and Institutional Background Mayor, City Administrator, Finance Director, Law Director, City Engineer, and WPC Superintendent Public Meetings

12 Stream Characterization Collection System Description Combined sewer system Separate sewer system MS4 Key components Pump stations Regulators Siphons WWTP Evaluation Existing conditions Capacity Separate Report Submitted

13 122 Flow Monitoring Locations 60 LTCP Flow Monitor Locations 62 Other Flow Monitor Locations Data Collected in 5 Phases Data Analysis Identified Problem Areas High I/I Areas Targeted for Inflow Reduction (Catch Basin Disconnection from Combined Sewer System)

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15 Entire City - Basins Group No. Average Dry Weather Flow (MGD) Maximum Flow (MGD) Average Peaking Flow Factor Central Group 1,3,5 & North Group 7-11 & Southwest Group 17 & South Central Group 4,14 & East Group 2,12,13,16 & Interceptor North Basin Group No. Average Dry Weather Flow (MGD) Maximum Flow (MGD) Average Peaking Flow Factor Group Group Group Group Group Group

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17 Analyzed Flow Monitoring Data to Identify Areas with High Inflow City Crews Investigated High Inflow Areas City Documented Storm Sewers, Catch Basins, Yard Drains, Downspouts, etc. Connected to Combined System Updated GIS with Info from City Investigations Performed Flow Metering in High Inflow Areas to Update Model

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19 Fig 5-3 from N Report

20 Basin Southwest South Central East North Group Peak Overflow for 1 Event (MGD) Maximum Total Overflow Volume for 1 Event (MG) Total Overflow Volume for Entire Typical Year (MG) Number of Overflow Events Total

21 Basin Group Peak Overflow for 1 Event (MGD) Peak Overflow Removed for 1 Event (MGD) Maximum Total Overflow Volume for 1 Event (MG) Total Overflow Volume for Entire Typical Year (MG) Number of Overflow Events Southwest South Central East North Total

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23 Basin Group Project Area Cost Peak Flow Removed (Typical Year) (MGD) Cost / Gallon Removed Southwest $388, $ $633, $ $653, $0.17 South-Central $271, $ $90, $ $312, $ $368, $ $382, $ $655, $ $447, $0.08 East 20.3 $467, $ $64, $ $449, $ $356, $ $364, $ $293, $ $282, $0.09 North $233, $ $431, $ $268, $ $589, $0.10 Total $7,995,

24 System-Wide Hydraulic Model Calibrated Model with Flow Monitoring Data Developed the Typical Year Established Existing System Conditions Modeled Alternatives to Determine Size of New Infrastructure

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26 Executive Committee Considerations: Minimize Disruption to Residents Provide Community Benefit from Project Convey As Much Flow As Possible to Treatment Plant Store Excess Flow at Plant Rather than in Collection System Aesthetic and Odor Concerns Alleviate Kingsbury PS Maximize Existing Infrastructure Cost Conscious Alternatives

27 4 Overflow Events During a Typical Year 0 Bypasses at the WWTP Significant Reductions in Early Stages Maximize Existing Infrastructure Maximize Flow to the WWTP Maximize WWTP Wet Weather Capacity Consolidate Storage at the WWTP Reduce Burden to 2.0% of MHI Develop a Feasible Implementation Schedule

28 3 Level Screening Approach Level 1 Level 2 Non-Monetary Factors Feasibility & Preliminary Cost Level 3 Cost & Performance

29 Feasible Alternative Categories Maximize existing infrastructure Inflow reduction Storage Pump station upgrades WWTP upgrades

30 LTCP Update Project Project Description Early Action Projects Projects Begin in 2015 Inflow Reduction Remove Direct Stormwater Connections CSO Regulator Modifications Collection System & Pump Station Projects WWTP Capacity Upgrade Storage Basin Remove Float-and-Gate Systems and Raise Weirs Pump Station Upgrades and In-Line Storage Step-Feed Modification for 10 MGD Wet Weather Capacity Two Phase Earthen Basin

31 Joint Community Benefit: Riverwalk/Bike Path Along River Inflow Reduction Areas Executive Committee Considerations: 1. Minimize Disruption (Forcemain on North vs. Second St.) 2. Community Benefit (Riverwalk/Bike Path and Riverbank stabilization) 3. Convey Flow to WWTP (Minimal In-Line Storage in System) 4. Store Flow at WWTP vs. System (Storage Basin at WWTP) 5. Alleviate Kingsbury PS (New Kingsbury PS Conveys Flows to North) 6. Maximize Existing Infrastructure (Express Sewers on South Side)

32 Upgrade to 10 MGD Wet Weather Capacity Convert to Step Feed in Aeration Tanks Mode of operation during wet weather conditions Modify existing tanks to create step feed zones Consistent operation during dry weather conditions Total Cost =$3.0M

33 Earthen Storage ~ 9 Million Gallons City-owned property near WWTP Two Basins Phase I 5 Million Gallons Phase II TBD Total Cost = $6.1M

34 CSO Volume Overflow WWTP Bypass Volume Total Overflow Volume Stored Volume WWTP WWTP Treated Flow Volume Wet Weather Percent Volume Reduction Model Million Gallons / Typical Year % Wet Weather Percent Captured Existing Conditions Selected Alternatives % Overflow Reduction Upon Completion 98% Capture of Wet Weather Flow Upon Completion

35 Permitted Outfall ID Existing Conditions Number of Overflows (#/year) Overflow Volume (MG/year) Projected Control of LTCP Update Number of Overflows (#/year) Overflow Volume (MG/year) Overflow Volume % Reduction WWTP Bypass % A % A % A % A A % A % A % A % A % A % A % A % A % A % A % A % A % M % M % NE % NE % NE % MH % MH % MH % MH % MH % MH % Permitted Outfall ID A-07 Closed A-08 Closed M-1 Closed M-2 Closed M-3 Closed M-4 Closed M-5 Closed M-8 Closed M-9 Closed NE-2 Closed MH-24 Closed MH-183 Closed MH-454 Closed MH-1043 Closed MH-1801 Closed MH-1818A Closed

36 LTCP Update Project Estimated Cost Early Action Projects $1,300,000 Inflow Reduction $7,600,000 CSO Regulator Modifications $2,037,173 Collection System & Pump Station Projects* $28,446,787 WWTP Capacity Upgrade $3,026,897 Storage Basin $6,140,425 Total Cost $48,551,282 * - Cost of Programmatic Reviews has been included in the Collection System & Pump Station Projects Cost

37 $60.0 Estimated LTCP Investment ($ Millions) $55.0 $50.0 $45.0 $40.0 $35.0 $30.0 LTCP Update Control Goal Knee of the Curve Overflow Events During a Typical Year

38 LTCP Update Total Cost = $48.6 Million US EPA Affordability Guidance 2.4% of MHI (2% is EPA Recommended Threshold) Qualifies for a 20 Year Schedule (FCA Guidance) Considered High Burden City contracted with Professor from Rutgers University to Perform Affordability Analysis High poverty rates in Defiance City s goal to keep burden at 2% 25 year schedule Ongoing Rate Study

39 25 years Aggressive Schedule 72% Overflow Reduction in 7 years Phased Approach Programmatic Reviews Re-evaluation period Update future phases based on data Storage at WWTP in 2 Phases

40 LTCP Update Projects Project Start Project End Early Action Projects Ongoing Phase I Year 1 Year 9 Inflow Reduction (IR) Year 1 Year 5 RWI Elimination Year 3 Year 6 WWTP Improvements Step Feed Year 4 Year 6 WWTP Storage - Basin I Year 5 Year 7 Phase I Programmatic Review Year 6 Year 9 Phase II Year 10 Year 22 South Basin Improvements Year 10 Year 12 Northeast Improvements Year 13 Year 16 Kingsbury Improvements Year 16 Year 19 Northwest Improvements Year 19 Year 20 Phase II Programmatic Review Year 20 Year 22 Phase III Year 23 Year 25 WWTP Storage - Basin 2 Year 23 Year 25

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42 Technical Comment Meeting held between Ohio EPA and City/AECOM in February 2016 Hydraulic Model Discussion Typical Year Evaluation for 20 Years Ohio EPA Comment Letter Received March 2016 Requested Updated Cost for past 20 Year Typical Year Analysis Requested FCA Calculation Data City Provided Response June 2016

43 Contact Info: City of Defiance: Mark Lehnert WWTP Superintendent S.R. 281 East Defiance, OH AECOM: Caitlin Ruza, P.E. Project Engineer 277 W. Nationwide Blvd. Columbus, OH