Timothy McCann AECOM Keith Bovard Rocky River WWTP
WWTP Infrastructure Redundancy
Redundancy As NASA Would Say: A Backup Plan for the Backup Plan Nuclear Power Plant Wastewater Treatment Plant Page 3
Infrastructure Redundancy Infrastructure Redundancy Neglected in Early WWTPs Incorporated in New Construction and Rehabilitation Redundancy May or May Not be Part of Normal Operations Includes Piping, Tanks, Channels, etc. Page 4
Driving Forces for Redundancy Efficient Redundancy Design Practices, 2003 Survey of 46 Treatment Facilities Emergency/ Disaster Planning 12% Design Guidelines 21% Maintenance and Operation Efficiency 38% Regulations 29% Jank, Palmer, Ross 2003 Page 5
Infrastructure Redundancy Benefits Reduced Downtime Meet Regulations Avoid Bypasses Provide Required Treatment Savings on O&M Avoid Maintenance Issues Increased Plant Operation Efficiency Overall Cost Effectiveness Page 6
Additional Redundancy Measures Backup or Standby Equipment Pumps, Screening Spare Parts On-hand Instrumentation Redundancy or Backup Measures Sensors, Analyzers Emergency Contracts Sludge Disposal, Pumping Page 7
Redundancy 10 States Standards Sec. 53.6 Arrangement of Units Arrange units for O&M convenience Flexibility and ease of installation of future additions Continuous quality effluent Economical additions Sec. 54.2 Unit Bypasses Maintenance & emergencies Maintain effluent quality Page 8
Headworks and Preliminary Treatment Screening Grit Removal Equalization Tank Bypass Alternatives Redundancy or Backup Measures Page 9
Primary Treatment Primary Clarifiers Additional Tanks Replacement Equipment Influent & Effluent Channels and Pipes Chemical Feed Storage Pumping Page 10
Secondary Treatment Biological Treatment Tanks Additional Tanks Backup Equipment Bypass Channels and Pipes Sludge Lines Secondary Clarifiers Page 11
Advanced Treatment Bypass Channels and Pipes Nutrient Removal Nitrogen Phosphorus Filtration Process Tanks Equipment Page 12
Disinfection Bypass Channels and Pipes Process Tanks Chemical Feed UV Page 13
Solids Processing Digester Tanks Storage Tanks Bypass Piping Dewatering Gas Handling Disposal Page 14
WWTP Infrastructure Redundancy What Works Best for YOU? Rotate Equipment Use Tanks, Channels as Part of Normal Operations Emergency Use Only Tailor to Each Individual Plant Operator Experience What Will Work? What is Needed? Engineering Guidance Page 15
Rocky River WWTP Background and History
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Rocky River WWTP Information Serves 4 Communities Bay Village Fairview Park Rocky River Westlake Design Flow: 22.5 MGD Average Flow: 12.5 MGD Peak Influent Flow: 170 MGD February 2011 All Flow Through Bar Screens Submerged Outfall Page 20
1937 Plant Page 21
1937 Plant Description Grit Chamber Settling Tank Anaerobic Digestion Sludge Drying Beds Discharge to Spencer Creek Provided Capacity & Function Until 1960s Page 22
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1961 Plant Page 24
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1961 Plant Modifications Additional Screening & Comminutor Aerated Grit Removal Chemical Coagulant Feed Primary Clarification Effluent Chlorination Submerged Outfall to Lake Erie Sludge Thickeners and Anaerobic Digesters Vacuum Filtration and Sludge Incinerator Page 26
1961 Construction Photos Page 27
1961 Construction Photos Cont. Page 28
1975 Plant Page 29
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1975 Plant Modifications Ohio Water Pollution Control Board 1965 Required Secondary Treatment Average Flow: 10 MGD Peak Flow:20 MGD Granular Activated Carbon Filtration & Adsorption Added Settled Sewage Pump Station to Carbon Facility Additional Minor Upgrades Carbon Treatment Operated Less than One Year Page 31
Current Plant Page 32
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Current Plant Added four Fixed Film Reactors & Final Clarifiers Chlorine Contact Tanks Modified Settled Sewage Pump Station 45 MGD Capacity Four 15 MGD Pumps 42-inch Force Main to Reactor Building Additional Clarifier Tanks Page 34
Settled Sewage Pump Station Backup Project and Alternatives
Settled Sewage Pump Station Pumps Primary Treated Wastewater to Secondary Treatment Wet Well - Converted Chlorine Contact Tank Rehabbed Carbon Column Treatment Pump Station Flow from Primary Clarifiers and Auxiliary Clarifiers Page 36
Plan View Before Project Page 37
Section View Before Project Page 38
SSPS Backup Project Purpose All Flow to Secondary Treatment is through Existing Force Main Potential Issues with Pump Station No Secondary Treatment Pump Failure Force Main Failure Wet Well Issues Page 39
SSPS Potential Additional Issues Prevent Permit Violations Die-off of Microorganisms at Reactors Associated Odor Problems (Proximity to Houses) Start-up Timeframe for Reactor Activity Consequent Sludge Volume Wash-out Page 40
SSPS Backup Alternative #1 Submersible Pumps in Wet Well Redundant Pump Capacity Two Submersible Solids Handling Pumps 15 MGD @ 80 feet TDH each Use Existing Force Main Simple Modification Existing station remain online No gates required Interfere with Normal Operating Conditions Must be stored somewhere else onsite Page 41
Alternative #1 Page 42
SSPS Backup Alternative #2 Redundant Pump Station New Pump Station Two Vertical Turbine Pumps 15 MGD @ 80 feet TDH each Use Existing Force Main New Wet Well Collection Box Stop Plates in Wet Well Page 43
Alternative #2 Page 44
SSPS Backup Alternative #3 Redundant Pump Station and Force Main New Pump Station Two Vertical Turbine Pumps 15 MGD @ 80 feet TDH each Construct New Force Main New Wet Well Collection Box Operation Flexibility Page 45
Alternative #3 Page 46
Alternative #3 Continued Page 47
SSPS Backup Alternative #4 Contract Pumping Service Contract with Pump Rental Company Rent 30 MGD Pumping Capacity Pumps running and installed within 24 hours Full capacity within one week Run Temporary Force Main to Reactor Building Construct Permanent Piping at Reactor Building Page 48
SSPS Backup Alternative #5 Temporary Pumps and Wet Well Partition Similar to Alternative #4 Contract with Pump Rental Company Rent 30 MGD Pumping Capacity Pumps running and installed within 24 hours Full capacity within one week Run Temporary Force Main to Reactor Building Construct Permanent Piping at Reactor Building Install Partition Gates in Wet Well Page 49
Alternative #5 Page 50
Cost Comparison $4,500,000 $4,000,000 $3,500,000 $3,000,000 Alternative Cost Analysis $3,127,000 $3,958,000 $2,500,000 $2,000,000 $1,500,000 $1,649,000 $1,000,000 $500,000 $655,000 $414,000 $0 Alt. 1- Submersible Pumps Alt. 2- Backup Pump Station Alt. 3- Backup Pump Station and Force Main Alt. 4- Contract Pumping Service Alt. 5- Contract Pumping & Wet Well Partition Page 51
Alternative Selection Selected Alternative #5 Bypass Pumping Used Lift station rehabilitation in case of lift station malfunctioning, failure or force main rupture. Bypass Work Accomplished with Centrifugal Pumps Page 52
Bypass Pumping Design Pump Capacity 35 MGD Piping Layout Permanent Pipe Design Flap Gate Picture of Permanent Page 53
Design Project Wet Well Modifications Added Slide Gates to Wet Well Dividing Wall Slide Gate Additional Channel Gate Page 54
Additional Project Items Overflow Meter Pipe Painting Additional Level Sensors Split Wet Well SCADA Integration Page 55
Ohio EPA Project Notification Preventative Backup System Purpose: Maintain Flow to Secondary Reactors in the Event of a Failure to: Primary effluent pump station 42-inch force main. No Change to Treatment System Low Bidder: $650,000 Page 56
Settled Sewage Pump Station Backup Project Construction Phase
Permanent Pipe Construction Enable Connection of Temporary Pipe at Ground Level Empty into Reactor Building Wet Well Multiple 18-inch Connections with Knife Gate Valves Page 58
Bypass Pumps & Piping Dry Prime 6 Pumps 7 MGD Each Welded HDPE Pipe 3-18 Pipes to Reactors Pipe Header Air Relief Valves Drain Lines Knife Gate Valves Check Valves Page 59
Wet Well Preparation & Utilization Temporary Bulkhead Portion of Wet Well Maintain Flow to Portion of Wet Well for Bypass Pump Intakes Allow Installation of Wet Well Gates & Dividing Wall Page 60
Wet Well Slide Gates & Divider Wall Divider Wall Construction Three New Slide Gates New Level Sensors Used Existing Conduit & Spare Wiring Page 61
Operations During Construction Equipped with Alarms to Notify Operations Staff of Unit Failure or Loss of Power. SCADA Wet Well Levels and Transformer Availability VFD Performance Pump Pressure Page 62
Current Availability in Case of Emergency Some after-project equipment and materials maintained onsite. Line item Budget reserved for Emergency Contracts. Proposals received for projected use of pumps and piping equipment. Page 63
Construction Challenges Permanent Pipe Pad Existing Unknown Duct Bank Permanent Piping Modification for New Flange Air Release Electric or Diesel Pumps? Wet Well Temporary Bulkhead Noise & Spill Containment Bypass Demobilization Page 64
Future Redundancy
Current Backup Systems Dual Primary (Single-stage) Digesters and Mixers, Thickeners and Sludge Heaters Two Belt Filter Presses, Polymer Systems, and Associated Feed And Washwater/Filtrate/Sump Pumps Pump Station Galleys with Multiple Pump and Piping Configurations Chemical Storage Tanks and Pumps Page 66
Potential Future Redundancy Digestion Sludge Screening Storage Tanks Storm Tank Dewatering and Sludge Piping Additional Chemical Piping Water Main and Plant Circulation Piping Backup Generator Currently Second Power Source Page 67
Questions? Thank You Tim McCann: Keith Bovard: timothy.mccann@aecom.com kbovard@rrcity.com
References Janks B., Palmer T., Ross M. 2003. Efficient Redundancy Design Practices. Alexandria, VA: Water Environment Research Foundation. 2004. Recommended Standards for Wastewater Facilities. Albany, NY: Wastewater Committee of the Great Lakes--Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers