Vermont's largest utility announced Tuesday that it's working with farmers to build a manure digester in St. Albans that will turn cow manure from three farms into electricity and reduce phosphorous pollution into Lake Champlain.
Backers say the $8 million Green Mountain Power project will help meet about one-third of the U.S. Environmental Protection Agency's target for reducing farm phosphorous runoff into St. Albans Bay.
"Frankly, there's nothing else out there now that is even coming close to meeting that level of reduction for agriculture," said Sandra Levine of the Vermont office of the Conservation Law Foundation.
Phosphorus-laden runoff of rain and snowmelt from farms, roads and parking lots, and discharges from municipal wastewater treatment plants feed toxic algae blooms in the lake.
The EPA this summer set new pollution reduction goals for the Vermont side of the lake, breaking them down by total maximum daily loads of phosphorus for different segments of the lake and from different sources.
For agriculture, the phosphorus reduction goals range from 0 percent in the Burlington bay to 32 percent in St. Albans Bay and 82 percent in Missisquoi Bay, Levine said.
The digester process will remove much of the phosphorous from the manure and the remaining fiber will be turned into animal bedding, which farmers say has become more costly and harder to get.
The harvested phosphorus, which is a necessary nutrient for growing corn and other crops, could also become a valuable commodity, GMP officials and farmers say. GMP is looking to sell it, possibly to composters for use in areas that have been depleted of the nutrient.
Taking the tractors and manure spreaders off the roads and pumping the manure out to the fields is a benefit for the roads and fields, which will be less compacted, said Paul Bourbeau, owner of one of the three farms.
Besides the pollution reduction benefits, the digester will generate enough electricity to power about 700 homes a year by using the methane gas from the manure.
GMP expects to start construction on the digester this summer, pending approval from the Vermont Public Service Board. It has plans for five other digesters in the Lake Champlain basin and is looking for partners, such as municipalities, to possibly help with those.