Biosolids Program Evaluation Walworth County Metropolitan (WalCoMet) - PowerPoint PPT Presentation

Biosolids Program Evaluation Walworth County Metropolitan (WalCoMet) Sewerage District Tom Foley, P.E. Omkar Ghavi, P.E.

BACKGROUND

WalCoMet Background › Serves 11 entities including Elkorn, Delavan, Darien, Williams Bay › 7.0 MGD/ 20.2 MGD › Class “B” liquid land application Walworth County Metropolitan Sewerage District

WalCoMet Background Walworth County Metropolitan Sewerage District

Existing Biosolids Process

Existing Biosolids Program › Biosolids applied to WalCoMet owned farm (300 ac) or to nearby farm fields ($) › Approximately 4,000,000 gallons land applied yearly

Goals › Analyze existing program and alternatives › Develop financial model › Identify low cost solutions › Provide recommendations

Biosolids Disposal Issues › Late harvest jeopardizes fall land application › Potential future issues: – Limited land availability – More stringent regulations – Increased solids production – Rising resource costs

Alternatives › Continued liquid land application › Dewatering & land application › Dewatering & landfilling › Class “A” sludge production – Composting – Lime Stabilization – Heat Drying – Thermophilic Digestion – Thermal Hydrolysis

Financial Modeling Tool › Input operating cost parameters › Track costs over 20 year planning period › View costs over time for the modeled alternatives

FINANCIAL MODEL DEVELOPMENT

Financial Model Parameters Parameters & More Parameters Finan ancial cial Model

Financial Model Development › Financial Model Components – Process – Economics › Adjustment to Input Parameters – Compare Scenarios › Quantity Costs for Alternatives – Capital Costs – O&M Costs – Present Value Costs

Financial Model • Planning Parameters • Capital Costs • O&M Costs  Labor  Electricity  Fuel  Chemical Financial • Revenue Data • Escalation Operating Data Sludge Management • Sludge  Daily Production  Handling • Sludge Hauling Scenarios  Stabilization  Land Application • No. of Units  Land Acquisition • Operating Hours  Landfilling • Chemicals  Outside Haulers Class A Biosolids Revenue •

Financial Model

Process Model Sludge Production Model Output Operational • Annual Solids Process Parameters (Class A/ Class B) Model • Consumables (Chemicals, Power, Natural Gas, Fuel, etc.) Treatment Performance

Process Model Mass Balance

Model Output

Model Output

Model Output

SCENARIOS

Liquid Land Application $14,000,000 1 On Farm 5 $12,000,000 Haul <5 mi 2 Haul >5 mi 3 3 Cumulative Life Cycle Cost $10,000,000 4 Land Acquisition 4 2 Outside Hauler 5 1 $8,000,000 $6,000,000 $4,000,000 $2,000,000 $- 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036 Year

Land Acquisition $12,000,000 $10,000,000 Cumulative Life Cycle Cost $8,000,000 Haul 10 miles $6,000,000 Land Acquisition $4,000,000 $2,000,000 $- 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036

Land Acquisition $12,000,000 $10,000,000 Cumulative Life Cycle Cost $8,000,000 Haul 15 miles $6,000,000 Land Acquisition $4,000,000 $2,000,000 $- 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036

Liquid vs Solid Application $14,000,000 6 1 On Farm 2 Haul <5 mi $12,000,000 3 Haul >5 mi 5 4 Land Acquisition $10,000,000 3 5 Dewatering Cumulative Life Cycle Cost 4 2 6 Landfilling 1 $8,000,000 $6,000,000 $4,000,000 $2,000,000 $- 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036 Year

Liquid vs Solid Application $14,000,000 $12,000,000 $10,000,000 Cumulative Life Cycle Cost $8,000,000 Dewatering Haul/Land Apply on Farm $6,000,000 $4,000,000 $2,000,000 $- 2016 2021 2026 2031 2036

Liquid vs Solid Application $14,000,000 $12,000,000 Cumulative Life Cycle Analysis $10,000,000 $8,000,000 Dewatering (2x Fuel) Haul 15 miles (2x Fuel) $6,000,000 $4,000,000 $2,000,000 $- 2016 2021 2026 2031 2036

Liquid vs Solid Application $14,000,000 $12,000,000 Cumulative Life Cycle Analysis $10,000,000 $8,000,000 Dewatering (2x Fuel) Haul 15 miles (2x Fuel) $6,000,000 Land Acquisition (2x fuel) $4,000,000 $2,000,000 $- 2016 2021 2026 2031 2036

Class “A” Alternatives $20 Millions Option B-1 Liquid Sludge Hauling A-4 Option B-2 Dewatering/Solids Hauling A-5 $18 Option A-1 Sludge Composting A-2 Option A-2 Heat Drying $16 A-3 Option A-3 Lime Stabilization Option A-4 Thermophilic Digester $14 A-1 Option A-5 Thermal Hydrolysis Cumulative Life Cycle Cost $12 B-2 $10 B-1 $8 $6 $4 $2 $- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Year

Recommendations › Current biosolids program is the lowest cost and proven option – Land acquisition and crop rotation will help ensure long term success › Capital costs of alternatives outweigh potential savings over a 20 year outlook › Monitor operation and maintenance costs using the model to track trends

Questions? › Tom Foley – tom.foley@clarkdietz.com › Omkar Ghavi – omkar.ghavi@clarkdietz.com