January 21, Presented by Lynne H. Moss, PE, BCEE

Transcription

1 January 21, 2011 Presented by Lynne H. Moss, PE, BCEE

2 Overview CRWS today Planning drivers Planning approach and key elements CRWS plan 2

3 CRWS Service Area 3

4 Existing Solids Management Train CRWS Solids Schematic 4

5 2007 Solids Management O&M Costs Offsite Biosolids Land Application, $3,029,687 Chemicals and Supplies, $2,011,992 Power, $705,943 Maintenance, $924,816 Labor, $940,720 5

6 CRWS Solids O&M Costs versus Others $700 $600 Cost per Dry Ton $500 $400 $300 $200 $100 $ $100 Los Angeles, CA; Anaerobic Digestion, Centrifuge Dewatering, Transport and Land Application $138 TRA CRWS; $196 West Palm Beach, FL; Dewatering and Drying $335 Philadelphia, PA; Anaerobic Digestion, Centrifuge Dewatering and Land Application/Landfilling $356 $367 Jacksonville, FL; Anaerobic Digestion, Centrifuge Dewatering and Drying Lowell, MA; Undigested, Belt-Press Dewatering and Landfilling/Incineration $547 Sacramento, CA; Anaerobic Digestion, Centrifuge Dewatering and Drying $577 Ocean County, NJ; Thickening at 3 Plants, Anaerobic Digestion, Transport to Central Facility, Belt-Press Dewatering and Drying Facility Name and Solids Handling Process 6

7 CRWS Land Application Cost Increases Time Period Annual Increase (%) % % % % % % / 14.4% (1) % (1) Includes $1.95 adjustment to price effective August 1,

8 Lime Stabilization RDP EnVessel System Do not use supplemental heat Estimated annual savings of $500K Plate and Frame Dewatering Consistently meets Class A Both streams rely on Class A Alt 3: Fecal coliform < 1,000 MPN/ g dry solids Enteric virus < 1 PFU/ 4g dry solids Helminth ova <1viable ova/ 4g dry solids 8

9 Drivers for CRWS Solids Master Planning Outlet Diversity Aging Infrastructure Growth Cost Master Planning Energy Efficiency 9

10 Master Plan Objectives Maximize the use of existing assets & improve efficiency through sludge reduction. Develop diversified & cost effective long term strategies to reliably meet solids processing needs. 10

11 And Overarching Solids handling is the heart of the plant. If you can t get rid of sludge then the whole plant is in trouble.

12 Overall Master Plan Approach PLANT ASSESSMENT FINANCIAL/CONTRACTUAL ASSESSMENT REGULATORY ASSESSMENT PRODUCT MARKETABILITY SOLIDS PROJECTIONS ALTERNATIVES DEVELOPMENT COST DEVELOPMENT PHASING Other Items: Energy Analysis PFRP Equivalency 12

13 Regulatory Assessment Summary Existing/Probable Requirements Potential Requirements Emerging Issues 40 CFR 503 Federal Standards for the Use or Disposal of Sewage Sludge - New molybdenum limit possibly by TAC 312 Texas solids beneficial use requirements 30 TAC Texas landfilling requirements 30 TAC 217, Subchapter J Texas solids handling facility design criteria Clean Air Act permits (40 CFR Parts 60 and 61) for sewage sludge incinerators Clean Air Act permits for dryers, boilers, and engines SB5/SB12 Texas energy reduction mandatory goal for political subdivisions Federal legislation mandating reductions in greenhouse gases Reclassification of biosolids as solid waste Additional pollutants (currently under consideration) included in 40 CFR 503 Replacement or supplement of 503 VAR requirements with new stability criteria P removal requirements in TPDES, with increase in sludge P Bioassay requirement to address microconstituent concerns New indicator organisms for pathogen reduction Additional pollutant controls in incinerator air permits (NOx, dioxins, furans, acid gases) Continued focus on microconstituents and emerging pathogens in biosolids Potential impacts of odor on health Reactivation and regrowth in anaerobically-digested & centrifuged biosolids; pathogen regrowth in Class A materials Potential elimination of Class A Alternative 3 and 4 and Class B Alternative 1 to demonstrate pathogen reduction P-based nutrient management in Class A land-applied biosolids NAAQS for ammonia Dioxin revisit 13

14 Market Assessment Approach Electronic Survey of Target Market Segments Define interest, opportunities, constraints Field Survey/Interviews Supplement electronic survey Focus on gatekeepers Identify competition Potential Demand Estimates Based upon surveys, land use 14

15 Market Assessment Summary Land application remains a viable alternative Compost demand is strong in DFW area, but supply is strong as well Strong local interest in heat-dried product Soil manufacturing an option for thermal hydrolysis product 15

16 Market Assessment Approach Electronic Survey of Target Market Segments Define interest, opportunities, constraints Field Survey/Interviews Supplement electronic survey Focus on gatekeepers Identify competition Potential Demand Estimates Based upon surveys, land use 16

17 Solids Production Estimates 17

18 Technology Screening Comments Total Compatibility with Existing CRWS Facilities Potental for Odor/Air Quality Impacts Ease of Permitting and Implementation Ease of Maintenance Ease of Operation Reliability Typical Scale Development Status Common Manufacturer(s) Description Technology Fine Screening Mechanical sludge screens with spacing between 3 and 10 mm. Screen types include bar, step, inline, rotary drum. Huber, Vulcan, Parkson Established Small to Large Screening size for municipal sludge typcially ranges between 2mm and 10mm. Ultra-Fine Screening Information not available on ultra-fine screening for sludge. n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a CEPT Chemical addition to primary clarifiers achieves enhanced particle removal. Increased quantity of chemical sludge compacts better and reduces secondary sludge production. n/a Established Small to Large Pilot testing was conducted at CRWS and data is available. Sludge can be thickened in primary clarifiers, reducing need Thickening in for downstream thickening. Co-settling in all clarifiers or Primary Clarifiers dedicated thickening clarifiers can be used. n/a Established Small to Large Field testing will be required. Biological Solids Reduction An interchange bioreactor reduces aerobic bacteria, and resulting facultative bacteria are dominated in aeration basins. Reduces overall secondary sludge production. Siemens (Cannibal) Innovative Small This technology is still emerging with only full scale applications for systems with flows less than 10 mgd. Chemical Solids Reduction WAS is treated with ozone to lyse bacteria cells, reducing sludge volume and mass. Navalis (Nautilus) Innovative Small to Medium RAS or MLSS is treated with ozone to lyse bacteria cells. Biochemical Praxair, Degremont Resulting COD is consumed in aeration basins, resulting in Solids Reduction (Biolysis O) decrease in sludge production. Embryonic Small to Medium n/a n/a n/a n/a n/a n/a n/a Concept is still in research and development stage. Wastewater treated in anaerobic baffled reactor to reduce Anaerobic Baffled mass of sludge produced. Longer sludge retention time, Reactor and resilient to hydraulic and solids load shock. n/a Established Small n/a n/a n/a n/a n/a n/a n/a Anaerobic baffled reactors typically used for very small systems in developing countries. Similar to IMHOF systems and septic system. Storage Sludge storage provides equalization prior to downstream thickening and dewatering processes, allowing system optimization. n/a Established Small to Large

19 Other Agencies Surveyed Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) New York City (NYC) City of Los Angeles (LA) Orange County Sanitation District, CA (OCSD) Philadelphia Water Department (PWD) Miami Dade Water and Sewer Department (MDWASD) District of Columbia Water and Sewer Authority (DCWASA) Massachusetts Water Resources Authority (MWRA) Allegheny County Sanitation Authority, PA (ALCOSAN) 19

20 Summary of Stabilization Practices MWRDC NYC LA OCSD PWD MDWASD Digestion Lime DCWASA MWRA ALCOSAN = Existing = Future 20

21 Summary of Utilization Practices Land Application Land Reclamation Landfilling or Landfill Cover material Thermal Drying Composting Incineration MWRDC NYC LA OCSD PWD MDWASD DCWater MWRA ALCOSAN = Existing = Future 21

22 Solids Management Alternatives Alternative Description 1 Lime Stabilization (Existing): Class A lime stabilization of dewatered, thickened primary solids and WAS 2 Primary Solids Mesophillic Digestion plus Lime Stabilization: Mesophillic digestion of thickened primary and thickened WAS followed by dewatering and Class A lime stabilization 3 Primary Solids Mesophillic Digestion plus Drying: Mesophillic digestion of thickened primary and thickened WAS followed by dewatering and drying 4 Thermal Hydrolysis of all Solids: Thermal hydrolysis of thickened primary and thickened WAS followed by mesophillic digestion, and dewatering 5 Class A Digestion of all Solids: Class A digestion of thickened primary and thickened WAS followed by dewatering 6 Class A Digestion of Primary and Thermal Hydrolysis of WAS: Class A digestion of thickened primary, with thermal hydrolysis and mesophillic digestion of thickened WAS, and combined dewatering 22

23 CRWS Solids Alternatives Capital Costs $140,000,000 $120,000,000 $100,000,000 $80,000,000 $60,000,000 $40,000,000 $20,000,000 $ 1. Lime 2. Meso Pr + Lime 3. Meso Pr + Drying 4. Thermal Pr & WAS 5. Class A Dig Pr & WAS 6. Class A Pr + Thermal WAS 23

24 $7,000,000 CRWS Solids Alternatives Annual O&M Costs $6,000,000 $5,000,000 $4,000,000 $3,000,000 $2,000,000 $1,000,000 $ 1. Lime 2. Meso Pr + Lime 3. Meso Pr + Drying 4. Thermal Pr & WAS 5. Class A Dig Pr & WAS 6. Class A Pr + Thermal WAS Power Labor Chemicals Hauling Gas 24

25 CRWS Solids Alternatives Annual O&M Costs Plus Debt Service $30,000,000 $25,000,000 $20,000,000 Total 30 year savings of Alt. 4 over Alt. 1 exceeds $120,000,000 $15,000,000 $10,000,000 $5,000,000 $ Lime 2. Meso Pr + Lime 3. Meso Pr + Drying 4. Thermal Pr & WAS 5. Class A Dig Pr & WAS 6. Class A Pr + Thermal WAS 25

26 Cost Evaluation Conclusions Lime was/is a good short term solution Due to haul costs, lime stabilization costs increase towards end of planning period Even without energy considerations, digestion (of some form) results in savings Energy value is considerable over planning period 26

27 Alternatives Non-Cost Evaluation Process Five criteria used for evaluation of process train alternatives Pair-wise comparison of criteria conducted with TRA staff Weighting factors from pair-wise used in comparing alternatives Alternatives scored 1-3 based on guidelines provided (with TRA Staff) Scores multiplied by weighting criteria to develop totals Final totals compared to rank the alternatives

28 Pair-wise Comparison of Criteria Each criteria compared to every other criteria to establish weighting factors Scoring range from 1-5, with 5 most important Criteria Evaluation Ease of Operation & Maintenance Site Requirements, Expandability, Compatibility Sustainability Product Odor 1 2 Ease of Operation & Maintenance Site Requirements, Expandability, Compatibility Sustainability Product Odor Interim Totals (60 possible) Score (100 total) Ranking

29 Weighted Criteria in the Final Priority Ranking Evaluation Criteria Ease of Operation & Maintenance Site Requirements, Expandability, Compatibility Sustainability Product Odor Description Score (1-3) Weight Factor Final Score Score (1-3) Weight Factor Final Score Score (1-3) Weight Factor Final Score Score (1-3) Weight Factor Final Score Score (1-3) Weight Factor Final Score Priority Score Ranking Existing Lime Stabilization Thermal Hydrolysis Class A Digestion (TPAD) Primary TPAD, WAS Thermal Hyd

30 Recommended Alternative: Thermal Hydrolysis of All Solids Primary Solids Thickening Pre- Dewatering Biogas Dewatering Class A Land Application Solids Screening Thickening Thermal Hydrolysis Mesophilic Digestion Landfill Compost WAS Amend -ment 30

31 Phased Implementation Recommended Repair/Replace aging infrastructure Minimize risks Regulatory Outlets Provide adequate solids handling capacity for growth in system Reduce costs through solids reduction All while: Recognizing cost pressures from customers Utilizing existing infrastructure 31

32 Existing Solids Handling 32

33 PHASE 1 Construct GT #7 Construct Primary Sludge Screening and Pump Station (without screens) Install 2, 2-M GBTs Install Scum Receiving/Storage Demolish Sand Filters and Equipment Decommission DAFTS Perform Immediate Structural Repairs to Incinerator Building New Decommission Demolish Rehabilitate Completed in Prior Phase 33

34 PHASE 2 Install Screens in Screening Facility Rehab GT #3-6 New Decommission Demolish Rehabilitate Completed in Prior Phase 34

35 PHASE 3 Demolish Equipment and Rehabilitate Structures Rehab 2 Existing Anaerobic Digesters Demolish DAFTS New Decommission Demolish Rehabilitate Completed in Prior Phase 35

36 PHASE 4 Demolish Thickening Structure and relocate Thickeners Install Thickening & Predewatering Equipment Decommission/Move Thickening Equipment Install New Thermal Hydrolysis Equipment New Decommission Demolish Rehabilitate Completed in Prior Phase 36

37 PHASE 5 Install Additional Predewatering Equipment Construct 2 New Digesters (3 & 4) Install Additional Thermal Hydrolysis Equipment New Decommission Demolish Rehabilitate Completed in Prior Phase 37

38 PHASE 6 Decommission FP, Install 1 Additional BFP and Modify Conveyance System Install Additional Predewatering Equipment Construct 3 New Digesters (5, 6, 7) Construct GT #8 Decommission and Demolish Install Additional Thermal Hydrolysis Equipment New Decommission Demolish Rehabilitate Completed in Prior Phase 38

39 ULTIMATE BUILDOUT CHP Units New Decommission Demolish Rehabilitate Completed in Prior Phase 39

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