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Home My WebLink About12.a. (Handout) Solids Treatment and Liquid Stream and Solids Treatment AlternativesV:\Client80\CCCSD\9945\cccsd0516\Handout\cccsd0516handout-9945(Solids).indd Alternative S-1 - Transition from MHFs to Two FBIs CCCSD Comprehensive Wastewater Master Plan – Solids Treatment Alternatives ALTERNATIVE S-1 This alternative consists of constructing two new FBIs to replace the existing multiple hearth furnaces (MHFs) as they reach the end of their useful lives. ADVANTAGES 1. Will eventually include all new process facilities to replace aging facilities. 2. Reduced emissions due to lower MACT limits. 3. Simpler operation vs. other alternatives (fewer individual unit processes). 4. Produces high quality ash product for beneficial reuse. 5. Small footprint relative to digestion alternatives. DISADVANTAGES 1. Requires more energy than Alternatives 2 and 3. 2. Highest GHG emissions. cccsd0416f21-9945.ai ALTERNATIVE 2 - SOLIDS CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN 1000 ft Gas Conditioning System Ash Thickeners Blend Tank Wet Weather Solids Storage Tanks Emergency Sludge Load Out Facility FBIs, ORC, Gas Turbine, and Vacuum Filter in existing solids building LEGEND Existing Solids Demonstration Project SITE LAYOUT PROCESS FLOW SCHEMATIC LEGEND Existing Solids cccsd0516f11-9945.ai ALTERNATIVE S2 - PROCESS FLOW DIAGRAM MHF WITH NEAR-TERM TRANSITION TO FBI FIGURE 2 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN L I M E P O L Y M E R 70.9 dtpd 1090 MMBTU/d Blend Tank (1) Solids Hoppers Fluidized Bed Incinerator (2) ORC Turbine (1) Gas Turbine (1) Landfill Demonstration Facility Ash for Beneficial Reuse Flue Gas Thermal Oil Boiler Thermal Oil Boiler 420 MMBTU/d 72 MMBTU/d Heat for Reuse (33° C) Heat for Reuse (100° C) Supplemental Heat 19 wtpd 66.9 dtpd 1040 MMBTU/d 4,600 kW 1,569 kW Gas Conditioning (1) Boiler 340 scfm 259 MMBTU/d 555 scfm 730z MMBTU/d L I M E P O L Y M E R 70.9 dtpd 1090 MMBTU/d Wet Weather Thickened Sludge Storage Tanks (2) Centrifuges (4) Primary Solids WAS 36.8 dtpd 603 MMBTU/d 32.0 dtpd 358 MMBTU/d DAFTs (3) LEGEND Landfill Gas Natural Gas Thermal Oil Heat Electricity New Equipment Solids Landfill Gas Natural Gas Electricity to Plant Solidslegendonly.ai LEGEND Landfill Gas Natural Gas Thermal Oil Heat Electricity Number of units(#) New Equipment Solids Transition from Multiple Hearth Furnaces (MHFs) to Two Fluidized Bed Incinerators (FBIs) Cost Summary (Millions) Estimated Capital Cost $350 Annual O&M Cost $2.0 Net Present Value $379 Total Greenhouse Gas Emissions - mt CO2-e/yr 16,400 Nu m b e r o f O b j e c t i v e s M e t TR I P L E B O T T O M L I N E + E V A L U A T I O N Ideal Alternative Alt S-1 S1 S2 E1 E2 F2 F1 T2 T1 E2 Global Impact S2 Assets E1 Local Impact S1 Health & Safety T1 Reliability/ Performance F2 Life Cycle $ F1 Capital $ T2 Efficiency DRAFT Note: Costs include major elements unique to this alternative for comparison. 12.a. V:\Client80\CCCSD\9945\cccsd0516\Handout\cccsd0516handout-9945(Solids).indd cccsd0416f18b-9945.ai ALTERNATIVE 3 - SOLIDS CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN 1000 ft Gas Conditioning System Solids Demonstration Project Sidestream Treatment Anaerobic Digestion Process Gas Treatment Gas Storage Ash Thickeners DAFT Tank (1) Blend Tank Emergency Sludge Load Out Facility Dryer, FBIs, ORC, Gas Turbine, and Vacuum Filter in exsiting solids building LEGEND Existing Solids FOG Receiving Station Alternative S-2 - Transition from MHFs to Digestion + Dryer + One FBI CCCSD Comprehensive Wastewater Master Plan – Solids Treatment Alternatives ALTERNATIVE S-2 This alternative includes the addition of digesters, dryers, and biogas energy recovery to the existing sewage sludge incineration process, with a phased replacement of the MHFs with one fluidized bed incinerator. Due to the timeline for FBI construction, only critical operational/compliance related MHF upgrades would be included. The digesters would be sized to process primary sludge (and po- tentially FOG), and accommodate maximum month Class B operation of all solids. Biogas system includes biogas treatment (hydrogen sulfide removal, dryer, and siloxanes removal), flares, and utilization in gas turbine. DISADVANTAGES 1. Adds digestion and bio- gas energy recovery pro- cesses to the treatment train, requiring operational knowledge and increasing mechanical maintenance requirements as compared to Alternative S-1. 2. Increased footprint above Alternative S-1. SITE LAYOUT PROCESS FLOW SCHEMATIC ADVANTAGES 1. New process facilities can be added in phases as required. 2. Increases reliability by providing storage upstream of MHFs. 3. Reduces load to MHF through digestion of primary solids. 4. Provides two stabilized solids haul-off options, improving resiliency. 5. Provides significant flexibility for future implementation of emerging technologies. 6. Provides opportunity for phased MHF replacement. 7. Produces high quality ash product for beneficial reuse. 8. Food, oil, and grease (FOG) import for additional biogas production could be accommodated with this alternative. 9. Fewer truck trips than Alternative S-1 or Alternative S-3. LEGEND Existing Solids cccsd0516f10b-9945.ai ALTERNATIVE S3b - PROCESS FLOW DIAGRAM DIGESTION + FBI FIGURE 3 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN PrimarySolids WAS Ash for Beneficial Reuse Receiving Station AnaerobicDigestion (4)FOG/Food Waste 36.8 dtpd 617 MMBTU/d P O L Y M E R L I M E 418 scfm 349 MMBTU/d32.0 dtpd 493 MMBTU/d Boiler Fluidized BedIncineration(1) 4,600 kW 1,160 kW Thermal Oil Boiler Flue Gas Thermal Oil Boiler 138 scfm 105 MMBTU/d 340 scfm 260 MMBTU/d 290 scfm 380 MMBTU/d 420 MMBTU/d 19 wtpd Solids Hoppers Class B Biosolids DAFTs (3) + 1 New DAFT Blend Tank (1) Sidestream Treatment Centrifuges (4) 47.7 dtpf 646 MMBTU/d Gas Conditioning (1) Gas Turbine (1) ORC Turbine (1) LEGEND Landfill Gas Natural Gas Biogas Thermal Oil Heat Electricity FOG/Food Waste New Equipment Solids Sidestream 50.6 dtpd 685 MMBTU/d 16.7 dtpd 216 MMBTU/d Landfill Gas Natural Gas Heat for Reuse (33° C) Supplemental Heat Electricity to Plant Dryer Transition from MHFs to Digestion + Dryer + One FBI Cost Summary (Millions) Estimated Capital Cost $340 Annual O&M Cost $2.1 Net Present Value $369 Total Greenhouse Gas Emissions - mt CO2-e/yr 8,700 Nu m b e r o f O b j e c t i v e s M e t TR I P L E B O T T O M L I N E + E V A L U A T I O N Ideal Alternative Alt S-2 S1 S2 E1 E2 F2 F1 T2 T1 E2 Global Impact S2 Assets E1 Local Impact S1 Health & Safety T1 Reliability/ Performance F2 Life Cycle $ F1 Capital $ T2 Efficiency Solidslegendonly.ai LEGEND Landfill Gas Natural Gas Thermal Oil Heat Electricity Number of units(#) New Equipment Solids DRAFT Note: Costs include major elements unique to this alternative for comparison. 12.a. V:\Client80\CCCSD\9945\cccsd0516\Handout\cccsd0516handout-9945(Solids).indd Alternative S-3 - Stand-Alone Digestion (Thermal Hydrolysis + Digestion) CCCSD Comprehensive Wastewater Master Plan – Solids Treatment Alternatives ALTERNATIVE S-3 Stand-Alone Digestion (Thermal Hydrolysis + Digestion) Abandon MHFs and transitions to a stand-alone digestion process, which will produce a Class A biosolids for beneficial reuse. The alternative includes thermal hydrolysis followed by mesophilic anaerobic digestion. Digesters sized for processing of PS, and TWAS. Sidestream treatment for ammonia reduction would be included. Biogas system includes biogas treatment (hydrogen sulfide removal, dryer and siloxanes removal), flares, and utilization in gas turbine. ADVANTAGES 1. Includes all new solids process facilities. 2. Includes energy recovery through production of biogas and cogeneration. 3. Reduces reliance on fossil fuels as compared to Alternative S-1. 4. Produces high quality Class A biosolids product. 5. Food, oil, and grease (FOG) import for additional biogas production could be accommodated to contribute toward “net zero” energy. 6. Most energy efficient and lowest GHG emissions. DISADVANTAGES 1. Adds multiple new processes to the treat- ment train, requiring operational knowledge and increasing mechanical maintenance requirements. 2. Increases odor control unit requirements. 3. Largest footprint. 4. Requires development of new biosolids end- use program. 5. Highest number of truck trips for disposal of biosolids. cccsd0516f19-9945.ai ALTERNATIVE 4 - SOLIDS CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN 1000 ft New Anaerobic Digestion Process New Dewatering Centrifuges and Gas Turbines Pre-Dewatering Sludge Screening, and THP System Gas Conditioning System Emergency Sludge Load Out Facility LEGEND Existing Solids Solids Demonstration Project Sidestream Treatment Gas Treatment Gas Storage FOG Receiving Station SITE LAYOUT PROCESS FLOW SCHEMATIC LEGEND Existing Solids cccsd0516f9-9945.ai ALTERNATIVE S4 - PROCESS FLOW DIAGRAM STAND-ALONE DIGESTION FIGURE 4 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN Primary Solids WAS Class A Biosolids for Land Application Gas Conditioning (1) Steam Anaerobic Digestion (3) Thermal Hydrolysis (3) 130 scfm 179 MMBTU/d 662 scfm 553 MMBTU/d Supplemental Heat 130 wtpd 13,100 lb/h 380 MMBTU/d 367 MMBTU/d 30 dtpd 1024 MMBTU/d 63.4 dtpd 493 MMBTU/d 32.0 dtpd 617 MMBTU/d 36.8 dtpd 4,600 kW Receiving Station FOG/Food Waste Polymer Polymer DAFTs (3) Blend Tank (1) Sludge Screens Centrifuges (4) Cake HoppersCentrifuges (4) Boiler Gas Turbine (1) 260 MMBTU/d 341 scfm Landfill Gas Natural Gas Electricity to Plant Sidestream Treatment LEGEND Landfill Gas Natural Gas Biogas Thermal Oil Heat Electricity FOG/Food Waste New Equipment Solids Sidestream Cost Summary (Millions) Estimated Capital Cost $380 Annual O&M Cost $2.0 Net Present Value $396 Total Greenhouse Gas Emissions - mt CO2-e/yr 3,800 Nu m b e r o f O b j e c t i v e s M e t TR I P L E B O T T O M L I N E + E V A L U A T I O N Reliability/ Performance Ideal Alternative Alt S-3 S1 S2 E1 E2 F2 F1 T2 T1 E2 Global Impact S2 Assets E1 Local Impact S1 Health & Safety T1 Reliability/ Performance F2 Life Cycle $ F1 Capital $ T2 Efficiency Solidslegendonly.ai LEGEND Landfill Gas Natural Gas Thermal Oil Heat Electricity Number of units(#) New Equipment Solids DRAFT Note: Costs include major elements unique to this alternative for comparison. 12.a. V:\Client80\CCCSD\9945\cccsd0516\Handout\cccsd0516handout-9945(Liquids).indd cccsd0516f3a-9945.ai 1000 ft ALTERNATIVE L1 – SITE LAYOUT MLE FIGURE 1 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN New Secondary Clarifiers A/N Tanks for Split Stream MLE ML Splitter Box 2 New PSTs New Grit Removal 72” FE Pipe Blower Building UV Hydraulic Improvements Chlorine Contact Basin Effluent Pump Station UV Refurbish Existing GMF GMF (for P Removal) Contaminated Soil (to be moved) Peak Wet Weather Flow Improvements Optimization/Reliability Level 2 Nutrient Limits 20 mgd RW for Refineries LEGEND 5 mgd Title 22 RW Level 3 Nutrient Limits Microfiltration Reverse Osmosis CEC Removal and/or IPR/DPR Facilities Raw Wastewater Diversion and Drainback Pipe Actiflo® (10 mgd) Drainback Pump Station Blower Building Reserved for Solids Handling New A/N Tanks cccsd0516f5-9945.ai ALTERNATIVE L1 – PROCESS FLOW DIAGRAM MLE FIGURE 1 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN CCT Grit Removal Grit Removal PEPS EPSUV Disinfection (Hydraulic Improvements) UV Disinfection Anoxic Selector Anoxic Selector PSTs PSTs Wet Weather Holding Basins Actiflo Refurbished GMF GMF for P Removal 43 – 40 0 170 41 127 41 104 18 104 13 110 5 23 23 MLE A/N Tanks Anoxic Selector MLE A/N Tanks Outfall Secondary Clarifiers Secondary Clarifiers Split Stream MLE Secondary Clarifiers To Exist RW Demand and CNWS3 Secondary Clarifiers IPS #5/6 IPS Bar Screens 270 1A 41 100 0 2 RO To Refinery RW Demand Brine Disposal 20 20 11 11 14 14 3 3 9 9 MF/UF Peak Wet Weather Flow Improvements Optimization/Reliability PWWF (mgd) ADWF (mgd)### ### Level 2 Nutrient Limits 20 mgd RW for Refineries LEGEND 5 mgd Title 22 RW Level 3 Nutrient Limits NOTES: 1. These are peak day and average annual RW demands. They don’t coincide with PWWF and ADWF. 2. Assuming no flow goes to existing RW demands during the winter. 3. Landscape irrigation for Concord Naval Weapons Station development. Drainback Pump Station and Pipeline Cost Summary (Millions) Estimated Capital Cost1 $382 Annual O&M Costs1 $8.8 Total Net Present Value1 $502 Total Energy Use (kW)1 7,145 SITE LAYOUT PROCESS FLOW SCHEMATIC CCCSD Comprehensive Wastewater Master Plan – Liquid Stream Treatment Alternatives: Biological Nutrient Removal (BNR) and Recycled Water Production ALTERNATIVE L-1 Expand on the existing activated sludge process and operate as a Modified Ludzack-Ettinger (MLE) process. The MLE expansion would be phased. The first phase would provide split flow nitrification/denitrification to produce 5 mgd for the nearby refineries. The second phase would provide nitrification/denitrification for an additional 15 mgd for the nearby refineries depending on the recycled water demand. The third phase would provide nitrification/denitrification of the full flow to meet proposed nutrient limits for discharg- ing effluent to Suisun Bay. Microfiltration (MF) and Reverse Osmosis (RO) are necessary to meet the recycled water quality for the refineries. The existing filter plant would be refurbished to supply non-nitrified water for the existing demands and future irrigation demands associated with the Concord Naval Weapons Station development. Alternative L-1 - MLE + MF + RO ADVANTAGES 1. Similar to existing process - reduces operations complexity and staffing requirements. 2. BNR facilities are contained in one location. 3. Costs are similar to Alternative L2. DISADVANTAGES 1. Requires early removal/relocation of sur- charge pile to construct recycled water facilities Phase 1 (5 mgd). 2. Larger footprint and would require moving into wet weather holding basin - A South to meet level 3 nutrient limits. 3. Requires additional process of MF for pre- treatment for RO process. Nu m b e r o f O b j e c t i v e s M e t Peak Wet Weather Flow Improvements Optimization/Reliability Level 2 Nutrient Limits 20 mgd RW for Refineries 5 mgd Title 22 RW Level 3 Nutrient Limits LEGEND cccsd0516f3alegendonly.ai NOTES: 1. These are peak day and average annual RW demands. They don’t coincide with PWWF and ADWF. 2. Assuming no flow goes to existing RW demands during the winter. 3. Landscape irrigation for Concord Naval Weapons Station development. cccsd0516f5legendonly.ai Peak Wet Weather Flow Improvements Optimization/Reliability PWWF (mgd) ADWF (mgd)### ### Level 2 Nutrient Limits 20 mgd RW for Refineries LEGEND 5 mgd Title 22 RW Level 3 Nutrient Limits MLE for future nutrient removal/Bay discharges, MF + RO for refinery recycled water production REFINERY RECYCLED WATER PRODUCTION PHASES Phase 1 - 5 mgd Phase 2 - 15 mgd TR I P L E B O T T O M L I N E + E V A L U A T I O N Ideal Alternative Alt L-1 S1 S2 E1 E2 F2 F1 T2 T1 E2 Global Impact S2 Assets E1 Local Impact S1 Health & Safety T1 Reliability/ Performance F2 Life Cycle $ F1 Capital $ T2 Efficiency (1) For meeting Level 2 nutrient limits and 20 mgd recycled water production for refineries. DRAFT Note: Costs include major elements unique to this alternative for comparison. 12.a. V:\Client80\CCCSD\9945\cccsd0516\Handout\cccsd0516handout-9945(Liquids).indd Alternative L-2 - MLE + MBR Cost Summary (Millions) Estimated Capital Cost1 $396 Annual O&M Costs1 $9.3 Total Net Present Value1 $523 Total Energy Use (kW)1 7,905 Ideal Alternative Alt L-2 CCCSD Comprehensive Wastewater Master Plan – Liquid Stream Treatment Alternatives: Biological Nutrient Removal and Recycled Water Alternatives ALTERNATIVE L-2 Add a Membrane Bioreactor (MBR) to recycled water for the nearby refineries. The MBR system would be constructed in two phases, depending on the demand from the refineries. Phase 1 would have a capacity of 5 mgd and Phase 2 would increase the total capacity to 20 mgd. A smaller expan- sion of the existing activated sludge process and conversion to a Modified Ludzack-Ettinger (MLE) process would provide nitrification/denitrification of the remaining flow to meet proposed nutrient limits for discharging to Suisun Bay. Reverse Osmosis (RO) is necessary to meet the recycled water quality for refineries. The existing filter plant would be refurbished to supply non-nitrified water for the exiting demands and future irrigation de - mands associated with the Concord Naval Weapons Station development. cccsd0516f4b-9945.ai ALTERNATIVE L2 – SITE LAYOUT MLE + MBR FIGURE 2 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN Contaminated Soil (Relocated to WWHBA - South) Blower Building UV Hydraulic Improvements New Primary Effluent Pumps for MBR 1 New PST New Grit Removal New A/N Tanks ML Splitter Box New Secondary Clarifiers New Primary Effluent Line Fine Screens 1000 ft Chlorine Contact Basin Effluent Pump Station UV Peak Wet Weather Flow Improvements Optimization/Reliability Level 2 Nutrient Limits 20 mgd RW for Refineries LEGEND 5 mgd Title 22 RW Level 3 Nutrient Limits Actiflo® (10 mgd) Refurbish Existing GMF GMF (for P Removal) MBR Blower Building Reserved for Solids Handling Raw Wastewater Diversion and Drainback Pipe 72” FE Pipe Reverse Osmosis CEC Removal and/or IPR/DPR Facilities Drainback Pump Station SITE LAYOUT PROCESS FLOW SCHEMATIC cccsd0516f6-9945.ai ALTERNATIVE L2 – PROCESS FLOW DIAGRAM MLE + MBR FIGURE 2 CENTRAL CONTRA COSTA SANITARY DISTRICT COMPREHENSIVE WASTEWATER MASTER PLAN Anoxic Selectors Secondary Clarifiers MLE A/N TanksGrit Removal PEPS EPS MBR Membrane Tanks RO UV Disinfection (Hydraulic Improvements) UV Disinfection 43 – 23 0 23 23 PSTs PSTGrit Removal Outfall NOTES: 1. These are peak day and average annual RW demands. They don’t coincide with PWWF and ADWF. 2. Assuming no flow goes to existing RW demands during the winter. 3. Landscape irrigation for Concord Naval Weapons Station development. To Refinery RW Demand Brine Disposal Anoxic Selectors MLE A/N Tanks Secondary Clarifiers GMF for P Removal Secondary ClarifiersWet Weather Holding Basins40 0 170 41 104 41 104 18 10 5 20 20 11 11 14 14 3 3 IPS #5/6 IPS Drainback Pump Station and Pipeline Bar Screens 270 1A 41 104 13 100 0 0 23 9 9 2 Peak Wet Weather Flow Improvements Optimization/Reliability PWWF (mgd) ADWF (mgd)### ### Level 2 Nutrient Limits 20 mgd RW for Refineries LEGEND 5 mgd Title 22 RW Level 3 Nutrient Limits CCTActifloRefurbished GMF 1 To Exist RW Demand and CNWS3 ADVANTAGES 1. Allows for construction of Phases 1 and 2 of recycled water while minimizing the amount of surcharge pile to be relocated. 2. Modular construction provides orderly expansion as required to meet recycled water demand. 3. Similar in cost to Alternative L1. 4. MBR process provides sufficient filtering for the RO process eliminating the need for MF. 5. Allows phasing of recycled water production inde- pendent of BNR additions for Bay discharge. DISADVANTAGES 1. MBR facilities would be separated from the main plant. 2. Some up-front costs make the initial 5 mgd recycled water production more costly than Alternative L-1. However, costs near equal if Phase 2 recycled water production is imple- mented. NOTES: 1. These are peak day and average annual RW demands. They don’t coincide with PWWF and ADWF. 2. Assuming no flow goes to existing RW demands during the winter. 3. Landscape irrigation for Concord Naval Weapons Station development. cccsd0516f5legendonly.ai Peak Wet Weather Flow Improvements Optimization/Reliability PWWF (mgd) ADWF (mgd)### ### Level 2 Nutrient Limits 20 mgd RW for Refineries LEGEND 5 mgd Title 22 RW Level 3 Nutrient Limits Peak Wet Weather Flow Improvements Optimization/Reliability Level 2 Nutrient Limits 20 mgd RW for Refineries 5 mgd Title 22 RW Level 3 Nutrient Limits LEGEND cccsd0516f3alegendonly.ai MLE for future Biological Nutrient Removal (BNR) for Bay discharges, MBR + RO for refinery recycled water production REFINERY RECYCLED WATER PRODUCTION PHASES Phase 1 - 5 mgd Phase 2 - 15 mgd Nu m b e r o f O b j e c t i v e s M e t TR I P L E B O T T O M L I N E + E V A L U A T I O N E2 S2 E1 S1 F1 F2 T2 T1 E2 Global Impact S2 Assets E1 Local Impact S1 Health & Safety T1 Reliability/ Performance F2 Life Cycle $ F1 Capital $ T2 Efficiency (1) For meeting Level 2 nutrient limits and 20 mgd recycled water production for refineries. DRAFT Note: Costs include major elements unique to this alternative for comparison. 12.a.