Dairy cows

Dairy cows feed at a Lower Valley dairy in September 2008. (Yakima Herald-Republic file photo)

GRANGER — After several years in the design process, work has started on a biogas conversion project at George DeRuyter & Sons Dairy that will convert tens of thousands of gallons of dairy manure and other materials into renewable natural gas.

The dairy is working with Brightmark Energy, a San Francisco-based waste and energy development company. The project will convert the dairy’s digester into a manure processing system and nutrient recovery system.

The system will be able to convert up to 150,000 gallons per day of dairy waste from up to 7,000 cows into the equivalent of 1.4 million gallons of gasoline.

“We can basically process our manure in a way that’s cost-effective and environmentally sustainable,” said Dan DeRuyter of George DeRuyter & Sons Dairy.

The new system will be able to convert waste and processed water into renewable natural gas that will be cleaned, upgraded and processed for direct injection into the Williams Northwest pipeline. The pipeline transports natural gas to various locations that supply fuel for commercial transport fleets, such as buses and trucks.

The project also includes the installation of a pipeline that will aid in the transport of natural gas from not only DeRuyter & Sons but others in the area who decide to pursue construction of similar systems.

Brightmark Energy is the majority owner of the system and will provide much of the funding to complete the project. It declined to provide an estimate of the total cost.

The firm will also oversee operations of the system once it’s complete. Brightmark is working on similar projects in New York, Wisconsin, Florida and Minnesota.

The project will be funded in part by a $1.4 million grant from Yakima County and a $500,000 Rural Energy for American Program grant from the U.S. Department of Agriculture.

“We are working to develop similar projects across the country to help dairy farmers mitigate the regulatory and environmental concerns associated with waste management, while transforming manure management from a cost center to a profit center,” Brightmark Energy CEO Bob Powell said in the company’s news release.

The converted digester is expected to start production by the final quarter of this year, said Dan Evans, president of Promus Energy, which had been working with the dairy on the project. The Seattle-based firm will continue to serve as project manager.

“Since the initial design of the project, the regional renewable gas market has matured to now recognize dairy-derived renewable natural gas as the cleanest transportation fuel available, which dramatically boosted the overall economics of the project,” Evans said.

DeRuyter’s effort to convert dairy waste into usable product dates back some 13 years. In 2006, he spent $3.8 million on a digester that converted the waste into electric power. However, the amount he received from Pacific Power dropped over several years, prompting DeRuyter to pursue using the digester for natural gas conversion back in 2012.