An unknown volume of partially untreated wastewater was released into the Lamoille River from the Town of Milton Wastewater Treatment Plant last week. The release occurred between Wednesday afternoon and Thursday morning, when operators at the plant discovered the problem.
“We had an upset at the wastewater plant that was caused by a block in the field,” said Milton’s Water & Wastewater Superintendent Roger Hunt.
Wastewater personnel relieved the partial blockage in sewage pipes leading to the plant on the afternoon of July 25. The next morning they learned that 40,000 gallons of septic wastewater had backed up behind the blockage and, after the pipes were unblocked, had flowed into the treatment plant. This sudden increase in volume reduced the effectiveness of the disinfection process.
“Because of an increase in turbidity,” said Hunt, “disinfection wasn’t able to kill E. coli.” The wastewater was treated for all other pathogens.
This partially untreated wastewater was released along with treated wastewater into the Lamoille River before plant operators discovered the problem.
“I don’t have all the testing results back,” said Hunt. Operators tested for Biochemical Oxygen Demand (BOD) Best, which is an “indicator of the effect of our treated wastewater on the river. It’s how organisms would react to whatever it is” that flowed into the river.
