Webster WPCF Biogas to RNG Task Rick Kenealy – Webster DPW Paul Adams – Webster Finance Director Bob Wimmer and Roberto Dabbas -- Navitas November 20, 2025
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Digester Gas
WPCF RNG Design and Pricing Scope Digester Gas is an Asset
• Where does it come from • Produced in Anaerobic Digesters • Conversion of solid material to gas • Primary sludge and waste activated sludge • High Strength Organic Waste – byproducts of food production, commercial kitchens
• What is in it • Energy – 60 to 70% methane (natural gas) • Water vapor • Carbon dioxide - 30 to 40% carbon dioxide
Digester Gas • Where does it go
WPCF RNG Design and Pricing Scope Digester Gas is an Asset
• Combusted in digester boilers (47% of average production) • Provides heat to digester building • Provides heat to the anaerobic digester tank • Reduces natural gas purchase
• Any excess is combusted in flare (53% of average production) • Required for safety and permit compliance • No financial benefit
•Four (4) Month Design Process WPCF RNG •Lead to amendment Design and documents, price and Pricing Scope guarantee •Permits •RNG Sale (Revenue Generation) Proposal Overview •Fee of $348,000
•Selection of Technology WPCF RNG •Design Documents Design and •Permitting Pricing Scope •RNG Sale (Revenue Generation) Proposal •Construction and Installation Tasks Pricing and Schedule
WPCF RNG Design and Pricing Scope
Technology
•Evaluate two (2) technology approaches • Cap-ex • Op-ex • Maintenance Requirements • Operator Experience • Vendor Experience
WPCF RNG •Conduct the Design Design and • Process Mechanical Pricing Scope • Site plan and structural • Electrical • Connection to RG&E gas main
Design
•Complete Permit WPCF RNG Applications Design and • Majority of Permits will be Pricing Scope
Permitting
minor modifications • New RG&E Interconnection Agreement
WPCF RNG Design and Pricing Scope
RNG Sales
•Establish value of the gas • Modeling of gas characteristics • Soliciting proposals for purchase • Establishing an offtake (revenue) agreement
WPCF RNG •Develop Amendment Design and • Detailed scope Pricing Scope • Schedule Price and Schedule
• Equipment Purchases • Price • Guarantee
WPCF RNG Design and Pricing Scope
Questions?