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Major Wisconsin manure-to-RNG project now operational

The partnership between three Wisconsin dairies and Brightmark, a San Francisco-based waste development company, has come to fruition this week with the first load of renewable natural gas (RNG) transported to the Dane County waste station RNG offloading station. The project was developed in close consultation with Dane County, WI, in order to maximize the benefits to the broader community.

“This will help local farms continue to be environmentally friendly to our community and help us to stay in compliance with environmental regulations,” says Chuck Ripp, co-owner of Ripp’s Dairy Valley with his brothers Gary and Troy. “We have always taken pride in being excellent stewards of land conservation and ensuring our land is a safe environment for our neighbors.”

Named the Demeter project, it will involve the conversion of 90,000 gallons of manure per day to RNG, which will be trucked to the county’s offload station from the anaerobic digester northwest of Madison, WI, purchased and upgraded by Brightmark in July 2019. The manure is supplied by the three dairies – Ripp’s Dairy Valley and Endres Dairy in Dane, WI, and White Gold Dairy in Waunakee, WI.

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 Dane 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.”

The RNG offloading station is part of a larger project to process the county’s landfill biogas for pipeline injection. Traditionally, each digester biogas producer is required to make a physical connection to the pipeline, which can cost millions of dollars for piping installation, equipment, and connection fees. Since the county was already making that connection for the landfill biogas project, an offloading station was added for other biogas producers to use. This project reduces the barriers for biogas producers to gain access to a pipeline, renewable energy markets, and the U.S. Environmental Protection Agency’s (EPA) and state issued renewable fuel credits.

The county’s offloading project was part of the 2018 budget and cost approximately $5.5 million for design, permitting, and installation. Users of the offloading station will be charged a fee to pay back the costs of installation and fund the operation of the facility. Price incentives are available for digesters in the Yahara watershed who participate in advanced phosphorus removal to further help incentivize cleaning up our lakes.