Attachment_C_VSD_WRF_Master_Plan_2025_-_Draft.pdf
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- Attached to
- VSD Campus Master Plan Analysis
- Solicitation number
- 2025-RFP-009
- Issued by
- Riverside County, Huntington Beach City, California
About this file
The document is a comprehensive Water Reclamation Facility (WRF) Master Plan prepared by Stantec Consulting Services for the Valley Sanitary District (VSD) in Indio, California. The master plan provides a detailed assessment and strategic roadmap for infrastructure improvements through 2045, covering the district's wastewater treatment facility. The plan includes evaluations of current facility conditions, projected population growth, wastewater flow and load projections, and recommended capital improvements. Key objectives include performing site inspections, assessing infrastructure conditions, identifying priority projects, and developing a capital improvement program with short-term (1-5 years) and long-term (5-20 years) recommendations.
The master plan outlines a projected annual population growth rate of 1.3%, with current average annual wastewater flow at 6 MGD expected to increase to 7.87 MGD by 2045. The total estimated capital improvement program cost is approximately $98 million, with phases ranging from 2027 to 2040. Significant proposed improvements include installing new aeration basins, a tertiary treatment facility, a Lystek solids handling facility, and various condition assessment repairs. The plan also highlights potential future regulatory requirements, such as anticipated nitrogen removal limits, and provides recommendations for upgrading treatment processes to meet future environmental standards. Funding for these improvements will likely come from the district's operational budget, with costs projected to increase from approximately $4 million annually in 2024 to $24 million by 2045.
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Valley Sanitary District Water Reclamation Facility Master Plan
St an te c
C on su lti ng S er vi ce s
In c.
Prepared for:
Valley Sanitary District
Prepared by:
Stantec Consulting Services, Inc.
April 2, 2025
Draft
September 30, 2025
Valley Sanitary District Water Reclamation Facility Master Plan
Revision Schedule
Revision Description Author Date Quality Check
Date Independent Review
Date
0 Draft Beth Cohen Venu Kolli
Table of Contents i
Acronyms / Abbreviations ......................................................................................................................... vi 1 Introduction ................................................................................................................................. 1-1
1.1 Acknowledgements ....................................................................................................................... 1-1
1.2 Introduction ................................................................................................................................... 1-1
1.3 Master Plan ................................................................................................................................... 1-2
1.4 Master Plan Scope ........................................................................................................................ 1-2
2 Executive Summary .................................................................................................................... 2-1
2.1 Study Area Planning Parameters .................................................................................................. 2-1
2.2 Wastewater Flows and Loads ....................................................................................................... 2-2
2.3 Potential Future Regulatory Requirements and Impacts on the Water Reclamation Facility ....... 2-3
2.4 Influent Pump Station and Headworks Analysis ........................................................................... 2-3
2.5 Primary Sedimentation Basins Analysis ....................................................................................... 2-4
2.6 Secondary Treatment Analysis ..................................................................................................... 2-5
2.7 Existing Pond Treatment System .................................................................................................. 2-6
2.8 Disinfection System Analysis ........................................................................................................ 2-7
2.9 Effluent Disposal Facilities ............................................................................................................ 2-7
2.10 Reclamation Facilities ................................................................................................................... 2-8
2.11 Solids Handling Facilities .............................................................................................................. 2-8
2.12 Filtrate Equalization Considerations ............................................................................................. 2-9
2.13 Condition Assessment Findings .................................................................................................. 2-10
2.14 Summary of Recommendations and Site Plan Phasing ............................................................. 2-12
2.15 Capital Improvements Program .................................................................................................. 2-19
3 Study Area Planning Parameters .............................................................................................. 3-1
3.1 Introduction ................................................................................................................................... 3-1
3.2 Master Plan Purpose and Objectives ............................................................................................ 3-1
3.2.1 Master Plan Objectives ................................................................................................................. 3-1
3.2.2 Master Plan Data Collection ......................................................................................................... 3-2
3.3 Master Plan Methodology and Process ........................................................................................ 3-2
3.3.1 Data Collection .............................................................................................................................. 3-3
3.3.2 Condition Assessment and Asset Evaluation ............................................................................... 3-3
3.3.3 Master Plan ................................................................................................................................... 3-3
3.3.4 CIP Development .......................................................................................................................... 3-4
3.4 Water Reclamation Facility Master Plan Chapters and Deliverables ........................................... 3-4
3.4.1 Water Reclamation Facility Master Plan Chapters ....................................................................... 3-4
3.5 District and Wastewater Background ............................................................................................ 3-5
3.5.1 Water Reclamation Facility History ............................................................................................... 3-5
3.6 Planning Data ................................................................................................................................ 3-6
4 Wastewater Flows and Loads .................................................................................................... 4-1
4.1 Introduction ................................................................................................................................... 4-1
4.2 Population Projections .................................................................................................................. 4-1
4.3 Historical Flows and Loads ........................................................................................................... 4-3
4.3.1 Historical Flow Data ...................................................................................................................... 4-3
4.3.2 Historical Biological Oxygen Demand Data .................................................................................. 4-5
4.3.3 Historical Total Suspended Solids Data ........................................................................................ 4-7
4.3.4 Historical Industrial User Data ...................................................................................................... 4-8
4.3.5 Historical Nitrogen Data .............................................................................................................. 4-10
4.3.6 Historical Temperature Data ....................................................................................................... 4-11 ii
4.3.7 Existing Flows and Loads ........................................................................................................... 4-12
4.4 Projected Future Conditions ....................................................................................................... 4-13
4.4.1 Flow Projections .......................................................................................................................... 4-13
4.4.2 Load Projections ......................................................................................................................... 4-14
4.4.3 Projected Flows and Loads ......................................................................................................... 4-17
5 Potential Future Regulatory Requirements and Impacts on the Water Reclamation Facility ...................................................................................................................................................... 5-1
5.1 Wastewater Discharge Permit ...................................................................................................... 5-1
5.2 Existing Effluent Limitations .......................................................................................................... 5-1
5.2.1 Existing Receiving Water (Coachella Valley Storm Water Channel) Limitations .......................... 5-2
5.2.2 Biosolids and Sludge Management .............................................................................................. 5-2
5.3 Competing Regulations ................................................................................................................. 5-3
5.3.1 SB 606 and AB 1688, Water Management Planning .................................................................... 5-4
5.3.2 Basin Plan Amendments, Salinity and Nitrogen ........................................................................... 5-4
5.4 Future Compliance Considerations ............................................................................................... 5-6
5.4.1 Disinfection Byproducts and Water Reuse (Title 22) .................................................................... 5-6
5.4.2 Pesticides ...................................................................................................................................... 5-7
5.4.3 Constituents of Emerging Concern ............................................................................................... 5-7
5.4.4 Per- and Polyfluoroalkyl Substances ............................................................................................ 5-7
5.4.5 Total Nitrogen ................................................................................................................................ 5-8
5.5 Design and Construction Regulations ........................................................................................... 5-8
6 Influent Pump Station and Headworks Analysis ..................................................................... 6-1
6.1 Headworks and Influent Pump Station .......................................................................................... 6-1
6.2 Existing Headworks Facilities ....................................................................................................... 6-1
6.2.1 Existing Influent Pump Station ...................................................................................................... 6-3
6.2.2 Existing Screening Facilities ......................................................................................................... 6-4
6.2.3 Grit Removal System .................................................................................................................... 6-7
6.2.4 Ferric Chloride System .................................................................................................................. 6-9
6.2.5 Headworks Biofilter ..................................................................................................................... 6-10
6.3 Headworks Design Flows and Hydraulic Analysis ...................................................................... 6-10
6.4 Recommended Improvements .................................................................................................... 6-12
7 Primary Sedimentation Basins Analysis .................................................................................. 7-1
7.1 Primary Treatment Facilities ......................................................................................................... 7-1
7.2 Existing Primary Treatment Facilities ............................................................................................ 7-1
7.2.1 Existing Primary Clarifiers Description .......................................................................................... 7-2
7.2.2 Existing Primary Effluent Channel ................................................................................................ 7-3
7.2.3 Existing Primary Sludge and Scum Pumps .................................................................................. 7-3
7.2.4 Historical TSS and BOD Removal Efficiency ................................................................................ 7-3
7.3 Primary Treatment Design Flows and Hydraulic Analysis ............................................................ 7-5
7.3.1 Surface Overflow Rate .................................................................................................................. 7-5
7.3.2 Weir Loading Rate ........................................................................................................................ 7-6
7.3.3 Hydraulic Retention Time .............................................................................................................. 7-7
7.4 Primary Treatment Facility Recommendations ............................................................................. 7-7
8 Secondary Treatment Analysis ................................................................................................. 8-1
8.1 Design Flows, Loads, and Effluent Requirements ........................................................................ 8-1
8.1.1 Secondary Treatment Basis of Design, Flows, and Loads ........................................................... 8-1
8.1.2 Secondary Treatment Basis of Design, Permit Limitations ........................................................... 8-2
8.2 Existing Secondary Treatment Facilities ....................................................................................... 8-3
8.2.1 Existing Selector Tanks (Anoxic Zone) ......................................................................................... 8-4 iii
8.2.2 Existing Aeration Tanks ................................................................................................................ 8-4
8.2.3 Existing Secondary Clarifiers ........................................................................................................ 8-5
8.2.4 Existing Return Activated Sludge/Waste Activated Sludge Pumps .............................................. 8-6
8.2.5 Existing Secondary Treatment Facility Design Criteria ................................................................. 8-7
8.2.6 Condition Assessment of Existing Secondary Treatment ............................................................. 8-7
8.3 Process Sizing of New Conventional Biological Nutrient Basins .................................................. 8-8
8.3.1 Process Sizing Approach, Conventional Biological Nutrient Removal (BNR) .............................. 8-9
8.3.2 Preliminary Sizing of Conventional Secondary Treatment Modeling .......................................... 8-10
8.4 Membrane Bioreactor Evaluation ................................................................................................ 8-16
8.4.1 Process Sizing Approach, Membrane Bioreactor ....................................................................... 8-16
8.4.2 Preliminary Results of MBR Secondary Treatment Modeling..................................................... 8-18
8.5 Recommendations ...................................................................................................................... 8-19
9 Existing Pond Treatment System .............................................................................................. 9-1
9.1 Pond 2 Summary .......................................................................................................................... 9-2
9.2 Pond 3 Summary .......................................................................................................................... 9-3
9.3 South Cell Summary ..................................................................................................................... 9-3
9.4 North Cell Summary ...................................................................................................................... 9-3
9.5 Pond Treatment System Recommendations ................................................................................ 9-4
10 Disinfection System Analysis .................................................................................................. 10-1
10.1 Existing Disinfection Facilities ..................................................................................................... 10-1
10.1.1 Chlorine Disinfection Principles .................................................................................................. 10-2
10.1.2 pH, Temperature, and Suspended Solids, Effects on Chlorination ............................................ 10-3
10.1.3 Contact Time and Short Circuiting, Effects on Chlorination ........................................................ 10-4
10.1.4 Chlorine Contact Basins Hydraulic Analysis ............................................................................... 10-5
10.2 Future Disinfection Facilities Options .......................................................................................... 10-6
10.2.1 UV Disinfection Principles ........................................................................................................... 10-6
10.3 Recommended Improvements .................................................................................................... 10-9
11 Effluent Disposal Facilities ...................................................................................................... 11-1
11.1 Existing Disposal Systems .......................................................................................................... 11-1
11.1.1 Effluent Disposal ......................................................................................................................... 11-1
11.1.2 Existing Solids Disposal .............................................................................................................. 11-1
11.2 Future Improvements .................................................................................................................. 11-1
11.2.1 Effluent Disposal ......................................................................................................................... 11-1
11.2.2 Solids Disposal ............................................................................................................................ 11-2
12 Reclamation Facilities .............................................................................................................. 12-1
12.1 Introduction ................................................................................................................................. 12-1
12.2 Title 22 Alternatives ..................................................................................................................... 12-1
12.3 Recycled Water Facility Recommendation ................................................................................. 12-3
13 Solids Handling Facilities ........................................................................................................ 13-1
13.1 Existing System ........................................................................................................................... 13-1
13.2 Lystek Thermal Hydrolysis Biosolids Feasibility Study ............................................................... 13-3
13.2.1 Design Parameters and Conditions ............................................................................................ 13-4
13.2.2 Infrastructure and Operations ..................................................................................................... 13-6
13.2.3 Environmental Assessment ........................................................................................................ 13-7
13.3 Recommendations ...................................................................................................................... 13-7
14 Filtrate Equalization Considerations ....................................................................................... 14-1 iv
14.1 Equipment Summary ................................................................................................................... 14-1
14.1.1 Drain Pump Station 2 Summary ................................................................................................. 14-1
14.1.2 North Cell Summary .................................................................................................................... 14-2
14.1.3 Drain Pump Station 3 Summary ................................................................................................. 14-2
14.2 RST Filtrate Return ..................................................................................................................... 14-3
14.3 BFP Dewatered Filtrate Return ................................................................................................... 14-4
14.4 Filtrate Flow Equalization and Return Analysis .......................................................................... 14-4
14.4.1 Fill and Return Recommendations .............................................................................................. 14-5
15 Condition Assessment Findings ............................................................................................. 15-1
15.1 Purpose of the Condition Assessment: ....................................................................................... 15-1
15.2 Scope of Assessment ................................................................................................................. 15-1
15.3 Assessment by Process Area ..................................................................................................... 15-2
15.4 Headworks .................................................................................................................................. 15-4
15.4.1 Influent Pump Station .................................................................................................................. 15-4
15.4.2 Influent Bar Screens .................................................................................................................... 15-7
15.4.3 Vacuum Truck Dump Pad ......................................................................................................... 15-11
15.4.4 Aerated Grit Chamber (Decommissioned) ................................................................................ 15-12
15.4.5 Vortex Grit Removal .................................................................................................................. 15-13
15.4.6 Odor Control Biofilters (Headworks) ......................................................................................... 15-13
15.4.7 Ferric Chloride Storage ............................................................................................................. 15-16
15.5 Primary Treatment .................................................................................................................... 15-17
15.5.1 Primary Sedimentation Equipment Gallery ............................................................................... 15-18
15.5.1 Primary Sedimentation Tank ..................................................................................................... 15-20
15.6 Secondary Treatment ................................................................................................................ 15-22
15.6.1 Selector Zones and Aeration Basins ......................................................................................... 15-22
15.6.2 Blower Building ......................................................................................................................... 15-26
15.6.3 Secondary Clarifiers .................................................................................................................. 15-29
15.6.4 Disinfection Facilities ................................................................................................................. 15-37
15.7 Solids Handling Systems .......................................................................................................... 15-58
15.7.1 Digester #2 ................................................................................................................................ 15-58
15.7.2 Boiler Facility ............................................................................................................................. 15-61
15.7.3 Digester Gas Handling .............................................................................................................. 15-63
15.7.4 Solids Dewatering and Drying ................................................................................................... 15-67
15.7.5 Ponds ........................................................................................................................................ 15-74
15.7.6 Effluent Junction Box ................................................................................................................ 15-80
15.7.7 Outfall Structure ........................................................................................................................ 15-82
15.8 Ancillary Systems and Facilities ................................................................................................ 15-83
15.8.1 Diesel Tank ............................................................................................................................... 15-83
15.8.2 Electrical Buildings .................................................................................................................... 15-84
15.8.3 Shade Structure 1 ..................................................................................................................... 15-91
15.8.4 Shade Structure 2 ..................................................................................................................... 15-92
15.8.5 Old Gas Generator Pad ............................................................................................................ 15-93
15.8.6 Lathe Building and Old Records Building ................................................................................. 15-93
15.8.7 Storage Areas ........................................................................................................................... 15-95
15.8.8 Administration, Operations, Lab, and Parking Area .................................................................. 15-97
15.8.9 PEMB Shop ............................................................................................................................. 15-100
15.8.10 CMU Shop ............................................................................................................................... 15-103
15.9 Summary and Recommendations ........................................................................................... 15-106
16 Summary of Recommendations and Site Plan Phasing ....................................................... 16-1
16.1 Recommendations ...................................................................................................................... 16-1
16.2 Site Plan Phasing ........................................................................................................................ 16-8 v
17 Capital Improvement Program ................................................................................................. 17-1
List of Tables
Table 2-1. Summary of Flow and Loads Projections .................................................................................................. 2-2 Table 2-2. Summary of Recommendations .............................................................................................................. 2-12 Table 2-3. Capital Improvement Program ................................................................................................................ 2-19 Table 2-4. Summary of Capital Improvement Program Capital Cost by Phase ........................................................ 2-21 Table 2-5. Historic O&M Annual Costs ..................................................................................................................... 2-22 Table 2-6. Projected O&M Annual Costs ................................................................................................................. 2-22 Table 4-1. City of Indio Projected Population ............................................................................................................. 4-2 Table 4-2. Summary of Existing Flows and Loads ................................................................................................... 4-12 Table 4-3. Summary of Flow and Loads Projections ................................................................................................ 4-17 Table 5-1. Existing Effluent Limitations ...................................................................................................................... 5-2 Table 5-2. Permit Limits for Land Application of Biosolids ......................................................................................... 5-3 Table 5-3. Water Conservation Effects on Salinity ..................................................................................................... 5-5 Table 6-1. Headworks Existing Capacity .................................................................................................................. 6-11 Table 7-1. Existing Primary Treatment Facility Design Criteria .................................................................................. 7-2 Table 7-2. Surface Overflow Rates for Different Flow Scenarios ............................................................................... 7-6 Table 7-3. Weir Loading Rates for Different Flow Scenarios ..................................................................................... 7-7 Table 7-4. Average Annual Hydraulic Detention Times .............................................................................................. 7-7 Table 8-1. Summary of 2045 Influent Design Parameters1 ........................................................................................ 8-2 Table 8-2. State Point Analysis Parameters and Results ......................................................................................... 8-15 Table 9-1. Summary of Pond Sizes ........................................................................................................................... 9-2 Table 9-2. Pond 2 Current Flows ............................................................................................................................... 9-2 Table 10-1. Chlorine Contact Tank 3 Design Criteria ............................................................................................... 10-6 Table 10-2. UV Disinfection System Design Criteria ................................................................................................ 10-8 Table 11-1. Permitted Discharge Capacity Limits .................................................................................................... 11-1 Table 12-1. Title 22 Tertiary Treatment Train Alternatives ....................................................................................... 12-1 Table 12-2. Filtration Alternative Comparison .......................................................................................................... 12-2 Table 12-3. Disinfection Alternative Comparison ..................................................................................................... 12-2 Table 13-1. Existing Solids Handling Design Criteria ............................................................................................... 13-1 Table 13-2. Design Parameters and Conditions ...................................................................................................... 13-4 Table 13-3. Lystek THP Major Module Components ................................................................................................ 13-5 Table 14-1. Design Criteria of Drain Pump Station 2 ............................................................................................... 14-2 Table 14-2. Design Criteria of North Cell ................................................................................................................. 14-2 Table 14-3. Design Criteria of Drain Pump Station 3 ............................................................................................... 14-3 Table 14-4. Hours of RST Operation Based on Plant Capacity and WAS Concentration ........................................ 14-4 Table 15-1. Condition Assessment Summary ...................................................................................................... 15-107 Table 16-1. Summary of Recommendations ............................................................................................................ 16-1 Table 17-1. CIP ........................................................................................................................................................ 17-2 Table 17-2. Summary of Capital Improvement Program Capital Cost by Phase ...................................................... 17-5 Table 17-3. Historic O&M Annual Costs ................................................................................................................... 17-5 Table 17-4. Projected O&M Annual Costs ............................................................................................................... 17-5
List of Figures i
Figure 2-1. Site Phasing Layout ............................................................................................................................... 2-18 Figure 3-1. Master Plan Project Execution ................................................................................................................. 3-4 Figure 3-2. Water Reclamation Facility Process Flow Diagram ................................................................................. 3-7 Figure 4-1. City of Indio population from 2010 to 2024 (U.S. Census Bureau) .......................................................... 4-1 Figure 4-2. Historical Influent Average Daily Flow Rate ............................................................................................. 4-3 Figure 4-3. Historical Influent Peak Hourly Flow Rate ................................................................................................ 4-4 Figure 4-4. Peaking Factors of PHF/AAF and PDF/AAF ............................................................................................ 4-5 Figure 4-5. Historical Influent BOD Concentrations from 2019 to 2024...................................................................... 4-6 Figure 4-6. Historical Influent BOD Load From 2019 to 2024 .................................................................................... 4-6 Figure 4-7. BOD Peaking Factors of PMF/AAL and PDL/AAL ................................................................................... 4-7 Figure 4-8. Historical Influent TSS/BOD Ratios from 2019 to 2024 ........................................................................... 4-8 Figure 4-9. Historical Industrial Flow .......................................................................................................................... 4-9 Figure 4-10. Historical Industrial Loading ................................................................................................................... 4-9 Figure 4-11. Historical TKN/BOD Ratio From July 2019 to July 2024 ...................................................................... 4-10 Figure 4-12. Historical Temperature Data ................................................................................................................ 4-11 Figure 4-13. Projected Flow and Population ............................................................................................................ 4-13 Figure 4-14. Projected Flow (AAF, PDF, and PHF) .................................................................................................. 4-14 Figure 4-15. Projected BOD (AAL, PML, and PDL) .................................................................................................. 4-15 Figure 4-16. Projected TSS (AAL, PML, and PDL) .................................................................................................. 4-16 Figure 6-1. Headworks Site Plan ................................................................................................................................ 6-2 Figure 6-2. Influent Pump Station ............................................................................................................................... 6-3 Figure 6-3. Screening Facility (Climber Screens, Multi-Rake Screen, and Conveyor) ............................................... 6-4 Figure 6-4. Multi-Rake Bar Screen ............................................................................................................................. 6-5 Figure 6-5. Screening Conveyor ................................................................................................................................ 6-6 Figure 6-6. Compactor Passing Screening to the Dumpster ...................................................................................... 6-7 Figure 6-7. Vortex Grit Chamber ................................................................................................................................ 6-8 Figure 6-8. Vortex Grit Chamber and Grit Classifiers ................................................................................................. 6-9 Figure 6-9. Ferric Chloride Area ................................................................................................................................. 6-9 Figure 7-1. WRF Primary Sedimentation Basin.......................................................................................................... 7-3 Figure 7-2. Historical BOD Removal Efficiency .......................................................................................................... 7-4 Figure 7-3. Historical TSS Removal Efficiency ........................................................................................................... 7-4 Figure 8-1. VSD primary and secondary layout ......................................................................................................... 8-3 Figure 8-2. Selector tanks (anoxic zone) at the VSD plant ......................................................................................... 8-4 Figure 8-3. VSD Aeration Tanks ................................................................................................................................ 8-5 Figure 8-4. Secondary Clarifiers................................................................................................................................. 8-6 Figure 8-5. (a) Clarifiers 1 and 2 RAS Pumps (b) Clarifier 3 RAS pump .................................................................... 8-6 Figure 8-6. Biowin process model for VSD Secondary Evaluation ........................................................................... 8-10 Figure 8-7. State Point Analysis of the Existing Secondary Clarifiers ...................................................................... 8-14 Figure 8-8. MBR Process ......................................................................................................................................... 8-17 Figure 8-9. Biowin process model for VSD Secondary Evaluation ........................................................................... 8-17 Figure 9-1. Ponds Layout ........................................................................................................................................... 9-1 Figure 10-1. Chlorine Contact Tank 3 ...................................................................................................................... 10-1 Figure 10-2. Sodium Hypochlorite Degradation Curves ........................................................................................... 10-4 Figure 13-1. Lystek THP Design Process Flow Diagram (Lystek, 2025) .................................................................. 13-4 Figure 13-2. Proposed Lystek THP Layout (Lystek, 2025) ....................................................................................... 13-6 Figure 14-1. Drain Pump Station 3 ........................................................................................................................... 14-3 Figure 15-1. VSD WRF Site Aerial View .................................................................................................................. 15-1 Figure 15-2. VSD WRF Site Assessment ................................................................................................................. 15-3 ii
Figure 15-3. Influent Pump Station ........................................................................................................................... 15-4 Figure 15-4. Chipping of Coating ............................................................................................................................. 15-5 Figure 15-5. Corrosion on Lamppost and Gantry Crane Track ................................................................................ 15-6 Figure 15-6. Receiving Wet Well at IPS ................................................................................................................... 15-6 Figure 15-7. Deteriorated Concrete Top Slab at IPS ................................................................................................ 15-7 Figure 15-8. Influent Bar Screens ............................................................................................................................ 15-7 Figure 15-9. Traveling Screens and Conveyor Belt (left), Gates (6) Reportedly Not Sealing at Screening Structure (right) ........................................................................................................................................................................ 15-8 Figure 15-10. Instrument Corrosion ......................................................................................................................... 15-9 Figure 15-11. Sediment Accumulation Over Drainage System ................................................................................ 15-9 Figure 15-12. Two-Position Select Switch on Influent Bar Screen Control Panel .................................................... 15-9 Figure 15-13. Cracks and Signs Of Efflorescence on Screening Structure Wall .................................................... 15-10 Figure 15-14. Cracks and Spalling at Top of Screening Area ................................................................................ 15-10 Figure 15-15. Influent Bar Screen Control Panel.................................................................................................... 15-11 Figure 15-16. Vacuum Truck Dump Pad ................................................................................................................ 15-11 Figure 15-17. Vertical Cracks on the Walls ............................................................................................................ 15-12 Figure 15-18. Decommissioned Aerated Grit Chamber ......................................................................................... 15-12 Figure 15-19. Grit Removal .................................................................................................................................... 15-13 Figure 15-20. Biofilter System at Headworks ......................................................................................................... 15-14 Figure 15-21. Corrosion in Biofilter Ductwork ......................................................................................................... 15-14 Figure 15-22. Corrosion at Flow Switch & Flex Conduit ......................................................................................... 15-15 Figure 15-23. Leaning and Rusting Ductwork Support ........................................................................................... 15-15 Figure 15-24. Ferric Chloride Storage .................................................................................................................... 15-16 Figure 15-25. Ferric Chloride Staining on the Equipment and Instruments ............................................................ 15-17 Figure 15-26. Coating Chipping at the Control Panel ............................................................................................. 15-17 Figure 15-27. Primary Sedimentation Tanks (left), Parshall Flume (right) .............................................................. 15-18 Figure 15-28. Primary Sludge Pumps and Macerators in Gallery .......................................................................... 15-18 Figure 15-29. Pump Gallery Corrosion ................................................................................................................... 15-19 Figure 15-30. Access Hatch (left), Signs of Efflorescence on the South Wall (right) .............................................. 15-19 Figure 15-31. Corrosion on Piping and Valves ....................................................................................................... 15-20 Figure 15-32. Corrosion on the Scum Pumps Discharge Pipes and Supports (left), Scum Pump Control Panel (right) ............................................................................................................................................................................... 15-21 Figure 15-33. Primary Influent Channel (left), New Chain and Flight System (right) .............................................. 15-22 Figure 15-34. Cracks on Walls and Rusted Rebar Couplers .................................................................................. 15-22 Figure 15-35. Selector Tank (left), Aeration Basin (right) ....................................................................................... 15-23 Figure 15-36. Pipe Coating Chipping and Spot Corrosion ..................................................................................... 15-24 Figure 15-37. Rusted Embed Angles and Delaminating Coating Below Grating .................................................... 15-24 Figure 15-38. Missing Gravity and Lateral Pipe Support (left), Crack on the Wall (right) ....................................... 15-25 Figure 15-39. Excessive Corrosion on Ultrasonic Level Transmitter (left), Exposed Cable of Flowmeter, DO Probe, Ammonia Sensor, and Nitrogen Sensor (right) ...................................................................................................... 15-25 Figure 15-40. Concrete Cracks at the Aeration Basins .......................................................................................... 15-26 Figure 15-41. Cracks, Spalling, and Pop-outs on the Concrete ............................................................................. 15-26 Figure 15-42. Blower Building ................................................................................................................................ 15-27 Figure 15-43. Cracks on the Exterior and Interior Surfaces of Walls at the Blower Building .................................. 15-27 Figure 15-44. Rusted Roof Beams and Ledger Angles .......................................................................................... 15-28 Figure 15-45. Missing Pipe Support on Vertical Piping .......................................................................................... 15-28 Figure 15-46. Secondary Clarifier Mixer Liquor Channel ....................................................................................... 15-29 Figure 15-47. Secondary Clarifier Splitter (Right: Seized up Gate) ........................................................................ 15-30 Figure 15-48. Cracks and Signs of Infiltration and Efflorescence ........................................................................... 15-30 Figure 15-49. Clarifier No.1 and 2 Overview .......................................................................................................... 15-31 Figure 15-50. Clarifier Chipped Coating on the Bridge Railing ............................................................................... 15-32 iii
Figure 15-51. Clarifier Water Hose Pipe and Stand Corrosion ............................................................................... 15-32 Figure 15-52. Secondary Clarifier Drive Corrosion ................................................................................................. 15-33 Figure 15-53. Cracks on the Perimeter Wall at Clarifier 2 ...................................................................................... 15-33 Figure 15-54. RAS Pump Station 1 (left) and Pump Station 2 (right) ..................................................................... 15-34 Figure 15-55. Corrosion at Bolts, RAS Pump Station 1 (left) and RAS Pump Station 2 (right) .............................. 15-35 Figure 15-56. Flaking Coating at Piping at RAS Pump Station 1 (left) and RAS Pump Station 2 (right) ................ 15-35 Figure 15-57. Corrosion and Coating Chipping on the Pipes and Valves .............................................................. 15-36 Figure 15-58. Need Sun Protection for the Panels ................................................................................................. 15-36 Figure 15-59. Stained Crack on Precast Manhole.................................................................................................. 15-37 Figure 15-60. Chlorine Contact Tank 3 ..................................................................................................................
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