One of the town’s two drinking water wells is offline and will remain so until the source of its coliform contamination can be confirmed and corrected. Well #5 tested positive for coliform bacteria in both July and August. The town water system was chlorinated following the two positive results, and town officials say well #2 will provide ample safe water until well #5 is fixed.
Tim Kilhart, director of the Department of Public Works (DPW) explained the timeline of the contamination, its probable cause, what needs to be done, and what the town should consider in the future to prevent this situation from recurring at an Aug. 14 meeting of the Water Commission. The commission voted to accept Kilhart’s plan to address the contamination in well #5, and if the Department of Environmental Protection (DEP) agrees to the plan, the well could be back online within a few weeks.
Coliform bacteria occurs naturally in the environment from sources such as decaying plant or animal material. Kilhart said the DEP does not require that water consumers be notified of coliform contamination since it is generally harmless. E. coli, a subgroup of coliform, can cause illness, but neither the wells nor the water system tested positive for that strain.
Kilhart said that quarterly water tests in early July showed coliform in one of the town’s two drinking water wells, known as well #5, and also in the Bolton Road water tank and the tap water at Town Hall. The Department of Environmental Protection (DEP) was notified, and it directed the town to take well #5 offline and chlorinate it, and to chlorinate the entire water system as well. Those actions were taken, Kilhart said, and when test results showed no coliform, the DEP told the town to put well #5 back online and to test the water again in 30 days.
Town water was tested again on Aug. 5, and coliform was detected in both well #5 and the Bolton Road tank. DEP was again notified and told the town to take well #5 offline and chlorinate the entire system but not to treat the well until the contamination source was found. Kilhart said the town hired a contractor from a well-drilling company to use a camera to look for any problems inside the well. At about 56 feet below the surface, the camera showed water coming in from a fracture in the bedrock. Kilhart told the commission that biologists at the company the camera operator works for and the DEP believe the fracture is the source of the contamination.
Kilhart said the optimal solution, at least for the short term, is to use a Jaswell seal, which prevents surface water and water outside the well casing from flowing into the well. The system will cost about $4,290, and will take only a day to install. Once it is installed, DPW workers will again chlorinate well #5, then run the water from the well to waste and test it again to make sure it is coliform-free. If it is, the DEP will give the town permission to bring the well back online.
In addition to addressing the coliform in well #5, the DEP is also requiring the town to install an emergency chlorination system. Kilhart said the town purchased a system about 10 years ago, but it has never been used. A few parts such as tubing will need to be replaced, and chlorine will need to be purchased every six months because of its short shelf life, but the system should be ready very soon.
Water Commission Chair Cindy Russo asked Kilhart how many towns in Massachusetts still have “raw water,” municipal water that is not chlorinated. Kilhart said Harvard is in a minority, and none of our neighboring towns has raw water. He added that the town should consider hiring a professional to determine what it would take to switch to chlorinated water. Town Administrator Tim Bragan agreed, saying, “We’ve been fortunate to run this system as long as we have.” Water Commissioner Kyle Hedrick added that the town should also keep the possibility of using water from Devens on the table.
In the meantime, Kilhart said, well #2, the other drinking water well, can satisfy the water demands of the town, even after school starts in a few weeks. Russo praised Kilhart for getting to the bottom of the problem and finding a solution quickly, and Kilhart in turn praised DPW foreman Ron Gilbert for the part he played in the investigation. The DEP deadline for addressing the coliform issue is Sept. 7, and Kilhart said he believes the town will meet it.
