PITTSFIELD — A failed chemical pump caused the turbidity level of the city's drinking water to spike above federal standards last month, but residents were never at risk.
The Pittsfield Department of Public Utilities mailed out a two-page notice city water users with that assessment to show full disclosure of the March 2 incident. DPU officials said the state Department of Environmental Protection also was notified of the violation.
"We do not know of any contamination and none of our testing has shown disease-causing organisms in the drinking water," the DPU letter states.
City water department officials noted turbidity has no health effects but it can interfere with the disinfection of the water and lead to some microbial growth. Turbidity may indicate the presence of the disease carrying organisms, but further tests showed that wasn't the case.
The problem arose as the city was reactivating the Farnham Reservoir water supply after more than a year of being offline due to repairs to the reservoir dam and intake. Only the Ashley Reservoir water was being used at the time, but each water source requires a different set of chemicals for treatment.
As the switch to Farnham occurred, one of the chemical pumps failed, setting off an alarm indicating the turbidity level was at 1.5 nephelometric turbidity units, violating the Environmental Protection Agency standard of 1.0 NTU. City officials say the water treatment plant normally registers 0.6 NTU.
A backup pump was pressed into service after 60 to 90 minutes of higher-than-allowed turbidity.
"Right when we switched to the other pump, the turbidity level came right down," said city DPU Commissioner Bruce Collingwood.
Visually, the water looked fine.
"People wouldn't have noticed anything, even at 5.0 NTU, the water wouldn't look cloudy," he said.
Residents with any concerns can contact the city's water department at 413-499-9339.