There are eight Bedford households that rely on private wells for drinking water.
Heidi Porter, the town’s director of health and human services, has asked the Board of Health to advise those residents to test their water for the presence of PFAS.
The synthetic chemicals known as PFAS (per- and polyfluoroalkyl substances) are potentially harmful to human health, according to the Environmental Protection Agency.
Porter pointed out that the town suspended use of the Shawsheen Road wellfield two years ago because of rising levels of PFAS. All Bedford drinking water now emanates from the Massachusetts Water Resources Authority (MWRA).
For private well users, “The only requirement for testing is when the well is opened,” Porter told the board, with a retest recommended every 10 years. She said she wants the board to sign off on a letter to the users urging them to have their wells tested and share the results with her office.
Porter added that there are also a couple of dozen residences that use separate wells for irrigation. She also plans a letter to them, since some may consider the water potable – indeed, she said, one was granted a permit for consumption.
“There are some anecdotes that people use irrigation wells to fill their pools,” Porter said, and others use the water for vegetable gardens. “We want them to have guidance so they make good decisions.” If the water is contaminated, there are treatment and filtration options, as well as connection to town water, Porter said.
“PFAS is ubiquitous so it’s hard to identify the source,” Porter said. For example, two years ago, the chemicals were found in insecticides used to poison mosquitoes; it turned out the source of the PFAS was the spray’s containers. “There’s still a lot to be learned about this. There’s a lot of information out there, too.
“Burlington received all of their water from the ground and they had to buy into the MWRA, because their plant just wasn’t able to treat PFAS,” Porter noted.
When the Bedford wells were closed, it was noted that one possible source of PFAS was fire suppressant foam used often at Hanscom Field during training exercises decades ago. The wellfield is recharged by the Shawsheen River, whose headwaters include areas of the airfield.