Hamilton water users have been notified that raw, untreated water at an offline town well has tested positive for E. coli.
The notice is required by the state Department of Environmental Protection, according to Hamilton DPW Director Bill Redford. The test came as part of routine monitoring for the presence of drinking water contaminants.
The notice pertains only to users to the public water systems and not to properties that use a private well.
A raw (untreated) water sample collected on Monday, Jan. 4 from the town’s School Street well tested positive for E.coli, which is a fecal indicator. Fecal indicators are used to detect ground water sources that may be susceptible to fecal contamination which may contain harmful viruses or bacteria. The well was already offline at the time of the test and was pumped briefly to collect the sample, according to the notice. The well is only on to take samples as not as a supplemental source into the system, according to Redford, and a treated water sample taken at the same time was negative.
Additional samples also needed to be taken and that has happened, Redford said. Those tests have been dropped off at the lab and the results are expected back late Thursday or early Friday, Redford said.
Treated samples collected in the distribution system did not detect any fecal contaminants and water delivered to the taps in the Hamilton water system is disinfected with chlorine to kill viruses and bacteria, including E.coli.
The School Street well where the sample was taken is one of five sources that supply drinking water to Hamilton.
“In accordance with the federal Ground Water Rule requirements, we are notifying you of the situation and conducting additional sampling to evaluate the extent of potential fecal contamination and will take further actions as necessary,” the notice reads.
The complete notice can be found on the town website.