One of the town’s two public drinking water wells will remain offline after it tested positive for coliform following a repair that had been designed to address the problem.
Well #5 tested positive for coliform twice last summer, and was taken offline in mid-August. Department of Public Works Director Tim Kilhart said the remaining town well, well #2, is producing enough water to satisfy the current demands of the town, which include residents and businesses in the center of town as well as the schools.
In August, investigations into the source of the contamination showed a fracture in the bedrock that was allowing water to flow into the well, and the Massachusetts Department of Environmental Protection (DEP) agreed that water from that fracture could be the source of the coliform. A Jaswell seal was installed a few weeks later to prevent water outside the well casing from entering the well; the cost was $2,900. Following the installation, well #5 was chlorinated, and testing immediately after that showed no coliform. But a week later the well tested positive for the bacteria again.
Town Administrator Tim Bragan told the Press the next step is to determine if the chlorination procedure the town used just wasn’t effective enough or if there’s another contamination source. The town will hire a contractor to super-chlorinate the well. If tests show coliform still exists, Bragan said, Harvard might have to consider chlorinating its public water supply. When the problem was first discussed at a Water Commission meeting Aug. 14, Chair Cindy Russo said the town would need a study to determine what would be needed to switch to full-time chlorinated water, which most towns in Massachusetts already have.
Bragan said that even if well #5 eventually tests negative for coliform, the town should consider installing a mixer in the water tank on Bolton Road, an idea he presented to the Finance Committee at its Sept. 11 meeting. He said the mixer would keep colder water at the bottom of the tank blended with warmer water at the top of the tank, which would provide a less hospitable environment for bacteria. The cost for the mixer would be $17,500, and it would also be needed in the event the town switched to a chlorinated water system. Bragan said the committee agreed and would recommend a warrant article for a water tank mixer for Special Town Meeting in October.
This is not the first time a mixer has been considered. Kilhart told the Water Commission at a meeting on Dec. 7, 2017 that, following a positive test for coliform in the water tank that summer, the DEP wanted the town to add a mixer to its water tank to keep the water moving. It said water in a tank should be no more than 20 days old, while Harvard’s tank water at that time was 30 days old.
When the commission asked Kilhart if the town could just lower the volume of water in the tank, he said that wasn’t an option because the water tank is a source for the Fire Department to use as an initial attack on a house fire. He warned the commission that DEP regulations were continuing to get stricter, and if the town’s water supply continued to have positive hits for coliform, the DEP could eventually require chlorination.
