Brooks Farm considers digester
Facility could process organic waste
By Robert Cloud
Ron Brooks has proposed an aerobic digester on his dairy farm in the town of Lind.
He spoke to the Waupaca County Highway Committee when it met Thursday, Dec. 16.
Brooks said the project will be built and operated by Vanguard Renewables, based in Wellesley, Massachussetts.
Started in 2014, the company has six systems operating in New England, four currently under construction and another 10 planned, according to Vanguard CEO John Hanselman.
Brooks showed the committee a video with Hanselman speaking about Vanguard Renewables’ digester process.
“Food waste moves from being a very harmful greenhouse gas to a wonderful tool for decarbonization and regenerative agriculture,” Hanselman said.
Hanselman noted that anaerobic digestion is a means of processing organic matter.
First developed in Europe, Vanguard’s system is fairly new to the U.S.
Older U.S. digester processes have been “very simple, very low tech systems that ended up processing organic matter like manure, like food waste, but unfortunately those systems didn’t sequester that methane. So in fact, you had those greenhouse gases still being released into the atmosphere,” Hanselman said.
Vanguard’s processing system “allows us to take in food waste, large quantities of food waste, take all the manure from the farm, combine the two of them, extract the methane, that very dangerous greenhouse gas, clean that and use it to create electricity,” Hanselman said. “So we’re a self-sustaining system, but we also export that renewable natural gas back into the grid.”
The system works by placing large amounts of food waste in a large submerged tank known as the hydrolyzation station, heating it for five days, then feeding it into the main digester vessel.
In the vessel the food waste is mixed with liquid manure, which has microorganisms that eat food waste and emit methane.
A membrane in the dome over the digester captures the methane.
The gas is then prepared and compressed to send into natural gas pipelines for transmission.
After the gas is extracted from the waste, the remaining high nutrient liquid is turned into fertilizer.
While carbon and nitrogen remain, phosphorous is removed in order to protect the watershed, Hanselman said.
“Our overall mission is not only to get renewable natural gas, but to work with host farms to make their operation more sustainable – environmentally and economically,” Hanselman said.
Vanguard builds the facility and provides trained staff 24/7 to operate it.
Brooks told the committee that the facility represents a $35 to $40 million investment by Vanguard.
It can produce enough gas to heat 1,300 to 2,000 homes per day, Brooks said.
“Putting it on the farm is the right place because the effluent that’s used as fertilizer doesn’t need to be transported by truck,” Brooks said.
Brooks estimated that Vanguard would process about 200 tons of food waste per day, while his farm would produce about 110 tons of manure per day.
“Vanguard’s system needs the methanogens in the manure to process food waste,” he said.
Brooks asked the highway committee if Vanguard could install a pipeline for irrigation water in the road right-of-way of County Trunk A.
The pipeline would run south from Brooks Farm along County A, to fields west of Lind Center. It would go under Lind Center Road and under Walla Walla Creek.
Brooks said it would be a 12-inch pipeline inside a 16-inch sleeve, to help protect against leaks.
County Highway Commissioner Casey Beyersdorf said the county plans a major improvement project on County A.
Although plans are to start at the south end of the road, work could begin in the north so that the pipeline can be installed at the same time.
Brooks said that he has been negotiating for easements through farm fields south of his property if the county does not grant him access to the road right-of-way.
Representatives from the town of Lind said local residents oppose the pipeline and noted that there is a nearby artesan well at the town hall. The spring water is used by the public.
Ryan Brown, director of County Planning and Zoning, said the project would need a use permit from the county.
If the project receives permits from the couknty and the state Department of Natural Resources, it could start s early as the fall of 2022 or in the spring of 2023.