Dane County Sheriff's Office spokeswoman Elise Schaffer said the blast at the Clear Horizons LLC biodigester sparked a fire Wednesday that destroyed a $250,000 nylon inflatable cover over one of its three digesters. No injuries were reported, according to the Wisconsin State Journal.
Jim Ditter, chief executive officer for PPC Partners Inc., which owns Clear Horizons, said the company believes the explosion was caused by the ignition of methane gas as an employee started an electric blower. He said the digester won't be used until officials determine the definite cause of the explosion and ensure it's safe to begin operating again.
The Clear Horizons facility generates electricity by burning methane in manure and reduces phosphorus in manure that will be used on farms.
The company has come under the scrutiny of the Wisconsin Department of Natural Resources after three spills occurred at the facility within nine months, releasing more than 400,000 gallons of manure. The department also began investigating allegations that Clear Horizons failed to remove enough phosphorus from the waste.
Records released Wednesday showed the facility has also had issues with pipeline blockages and untreated animal waste.
"Definitely things like this have come up too often," said David Mosher, wastewater specialist at the state's Department of Natural Resources. "Right now we're just looking for avenues to get them in compliance with the permit."
If the violations continue, the department could levy fines of up to $1,000 per day or shut the plant down by revoking its permit.
Ditter said PPC Partners Inc. has spent a lot of money trying to search for solutions to the spills, blockages and adequate phosphorus reduction. The company is considering the addition of new equipment to reduce phosphorus levels.
"From our point of view it's been a huge investment, but it's been a huge plus for Dane County just in terms of the phosphorus we've removed and kept out of the lakes," Ditter said.