Holliston Adding Chlorine to Water Following Test Results Showing Five Samples had Coliform Bacteria

Holliston is adding additional chlorine to its drinking water, following an initial report that coliform bacteria had been found in five of 15 samples collected Wednesday.

The water does not have to be boiled by residents, but the town officials are in contact with the state Department of Environmental Protection about steps to be taken.

The town on Wednesday instituted a ban on outdoor watering, with a few exceptions, due to low levels in its tanks. On Thursday, that ban was expanded to cover all properties, with no exceptions.

In a statement, the Holliston Water Department said the presence of coliform bacteria is not, in of itself, cause for concern. The test results did not show the presence of e. coli bacteria, or fecal coliform.

"Although this is not an emergency, as our customers, you have a right to know what happened, what you should do and what we are doing to correct this situation," wrote Water Superintendent Ron Sharpin. "We routinely monitor for the presence of drinking water contaminants. According to a report received on July 11, five of fifteen of our samples collected on July 10 showed the positive presence of coliform bacteria. This exceeds acceptable standards."

Customers do not have to boil their water. However, if customers have specific health concerns, the town said they should consult their doctor. 

From the statement: "People with severely compromised immune systems, infants and some elderly may be at increased risk. These people should seek advice about drinking water from their health care providers. General guidelines on ways to lessen the risk of infection by microbes are available from EPA's Safe Drinking Water Hotline at 1-800-426-4791."

An additional round of tests was taken at the town's sampling locations on Thursday.

"Whenever we detect coliform bacteria in any sample, we do follow-up testing to see if other bacteria of greater concern, such as fecal coliform or E. coli, are present. We are adding additional chlorine to the water system."

The town also is in contact with the Department of Environmental Protection, which regulates public drinking water systems in Massachusetts, and that agency will evaluate whether additional action is required.

The announcement comes one day after the town ordered a ban on outdoor watering, due to low levels in its water tanks. The problem stemmed from a faulty electrical circuit board in a pumping station, which prevented the pumping of water into the system at the Dopping Brook treatment facility. The electrical repairs are being conducted.

As a result of the lowered water levels in the tanks, some customers may be experiencing cloudy or brown water, Sharpin wrote. 

He offered the following suggestions:

"Cloudy: Air in the line can cause the water to appear cloudy. To determine whether air bubbles are altering the appearance of drinking water, fill a clear glass with water and wait several minutes. If air is the culprit, the water will appear clear after the air bubbles have dissipated. There is no need for further action. If the bubbles persist, contact the Holliston Water Department."

"Brown: Disturbances in the water supply lines can stir up particles, such as iron deposits, which can cause the water to appear brown. When this occurs you may need to flush the line for longer than one minute until the problem clears."