Providing Infrastructure Redundancy at the Rocky River WWTP. Timothy McCann AECOM Keith Bovard Rocky River WWTP

Transcription

1 Timothy McCann AECOM Keith Bovard Rocky River WWTP

2 WWTP Infrastructure Redundancy

3 Redundancy As NASA Would Say: A Backup Plan for the Backup Plan Nuclear Power Plant Wastewater Treatment Plant Page 3

4 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

5 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

6 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

7 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

8 Redundancy 10 States Standards Sec Arrangement of Units Arrange units for O&M convenience Flexibility and ease of installation of future additions Continuous quality effluent Economical additions Sec Unit Bypasses Maintenance & emergencies Maintain effluent quality Page 8

9 Headworks and Preliminary Treatment Screening Grit Removal Equalization Tank Bypass Alternatives Redundancy or Backup Measures Page 9

10 Primary Treatment Primary Clarifiers Additional Tanks Replacement Equipment Influent & Effluent Channels and Pipes Chemical Feed Storage Pumping Page 10

11 Secondary Treatment Biological Treatment Tanks Additional Tanks Backup Equipment Bypass Channels and Pipes Sludge Lines Secondary Clarifiers Page 11

12 Advanced Treatment Bypass Channels and Pipes Nutrient Removal Nitrogen Phosphorus Filtration Process Tanks Equipment Page 12

13 Disinfection Bypass Channels and Pipes Process Tanks Chemical Feed UV Page 13

14 Solids Processing Digester Tanks Storage Tanks Bypass Piping Dewatering Gas Handling Disposal Page 14

15 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

16 Rocky River WWTP Background and History

17 Page 17

18 Page 18

19 Page 19

20 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

21 1937 Plant Page 21

22 1937 Plant Description Grit Chamber Settling Tank Anaerobic Digestion Sludge Drying Beds Discharge to Spencer Creek Provided Capacity & Function Until 1960s Page 22

23 Page 23

24 1961 Plant Page 24

25 Page 25

26 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

27 1961 Construction Photos Page 27

28 1961 Construction Photos Cont. Page 28

29 1975 Plant Page 29

30 Page 30

31 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

32 Current Plant Page 32

33 Page 33

34 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

35 Settled Sewage Pump Station Backup Project and Alternatives

36 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

37 Plan View Before Project Page 37

38 Section View Before Project Page 38

39 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

40 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

41 SSPS Backup Alternative #1 Submersible Pumps in Wet Well Redundant Pump Capacity Two Submersible Solids Handling Pumps 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

42 Alternative #1 Page 42

43 SSPS Backup Alternative #2 Redundant Pump Station New Pump Station Two Vertical Turbine Pumps feet TDH each Use Existing Force Main New Wet Well Collection Box Stop Plates in Wet Well Page 43

44 Alternative #2 Page 44

45 SSPS Backup Alternative #3 Redundant Pump Station and Force Main New Pump Station Two Vertical Turbine Pumps feet TDH each Construct New Force Main New Wet Well Collection Box Operation Flexibility Page 45

46 Alternative #3 Page 46

47 Alternative #3 Continued Page 47

48 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

49 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

50 Alternative #5 Page 50

51 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

52 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

53 Bypass Pumping Design Pump Capacity 35 MGD Piping Layout Permanent Pipe Design Flap Gate Picture of Permanent Page 53

54 Design Project Wet Well Modifications Added Slide Gates to Wet Well Dividing Wall Slide Gate Additional Channel Gate Page 54

55 Additional Project Items Overflow Meter Pipe Painting Additional Level Sensors Split Wet Well SCADA Integration Page 55

56 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

57 Settled Sewage Pump Station Backup Project Construction Phase

58 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

59 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

60 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

61 Wet Well Slide Gates & Divider Wall Divider Wall Construction Three New Slide Gates New Level Sensors Used Existing Conduit & Spare Wiring Page 61

62 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

63 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

64 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

65 Future Redundancy

66 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

67 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

68 Questions? Thank You Tim McCann: Keith Bovard:

69 References Janks B., Palmer T., Ross M Efficient Redundancy Design Practices. Alexandria, VA: Water Environment Research Foundation 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