An explosion at a problematic biodigester near Waunakee, Wis., destroyed a $250,000 nylon inflatable cover early Wednesday morning. The digester, owned and operated by Clear Horizons LLC, generates biogas from cow manure. The facility includes three 1.25-million-gallon digesters.The explosion sent a plume of smoke into the air, which could be seen for miles. No one was hurt in the incident.“A manure digester on the property had been emptied two days prior, and when workers started an exhaust fan, they heard a loud noise followed by the cover at the top of the digester bursting into flames,” says Elise Schaffer, spokeswoman
