June 11, 2020. The first-of-its-kind in the nation renewable natural gas (RNG) offloading station at Dane County, Wisconsin’s landfill today received its first load of RNG from a manure digester in the Yahara Lakes Watershed. Brightmark has completed construction of the multi-million-dollar project upgrading gas equipment at its digester northwest of Waunakee in the Town of Vienna.
The biogas converted from 90,000 gallons of manure per day will be trucked to the county’s offload station from the digester project. The digester captures methane and phosphorus from manure, which reduces greenhouse gas emissions and harmful runoff to lakes and streams. The digester’s biogas will be injected through the county’s equipment into the interstate transmission pipeline so it can be used as renewable fuel, powering fleets of RNG vehicles across the United States.
“Our project with Brightmark will help prevent greenhouse gas emissions from entering the atmosphere and significantly reduce phosphorus runoff into our lakes,” said County Executive Joe Parisi. “I am hopeful that revenue from the sales of digester RNG will spur the development of more digesters and increase our lake clean-up efforts.”
In 2010, the county with state and private funding contracted for the building of the state’s first community digester receiving manure from three family farms to improve the water quality of area lakes. Brightmark‘s new investment will create both long-term project viability and increased manure treatment from additional dairy farms.
RNG offers many climate benefits when compared to traditionally captured gas by drastically reducing the greenhouse gasses (GHGs) associated with agriculture. During the anaerobic digestion process, methane is captured as biogas and converted, rather than being released directly into the atmosphere. Research shows that when all climate benefits are considered together, RNG from dairy manure can reduce GHG emissions 400 percent when it is used to replace traditional vehicle fuels.
Methane is 25 times more potent to the atmosphere than carbon dioxide and when used as renewable vehicle fuel, every trailer that comes through Dane County’s offloading station will reduce GHG emissions equivalent to that of burning 24,000 pounds of coal. It is estimated that the project will deliver a trailer of gas to the landfill every 2-3 days.
The new digester project will produce enough fuel each to travel from San Francisco to New York and back over 200 times in a compressed natural gas vehicle.