Wellesley Department of Public Works Director Dave Cohen this week gave the Select Board an update on the town’s new challenges: Addressing elevated levels of “forever chemicals” called PFAS6 in the drinking water.
As we’ve previously reported, Wellesley is among a growing number of communities in the state testing for Per- and polyfluorinated alkyl substances (PFAS) in the drinking water as required under new state rules and finding unacceptable levels. Wellesley, which has been reaching out to the public in various ways to communicate about the subject, received confirmatory samples last week that appear to verify its status. So it’s on to coming up with possible long-term solutions that will enable Wellesley to get the Morses Pond treatment plant it took offline at the start of May back in action rather than just relying on its diverse water supply portfolio. This includes access to the Massachusetts Water Resources Authority supply, which is clean but pricey. The Morses Pond treatment facility handles 1 million to 1.5 million gallons of water per day, so Wellesley doesn’t want to be replacing that with more expensive water for longer than it has to.
In the short term, the DPW is running tests to pinpoint the well or wells that are sources of the contaminated water so that it can determine its needs.
One question that’s been on many local minds is whether the issue, given its discovery at the Morses Pond treatment facility, applies to the Morses Pond swimming water, too, as beach season approaches.
Cohen, speaking at the Select Board meeting (see a couple minutes into the meeting on Wellesley Media recording), clarified that the focus of the PFAS investigation is samples pulled from ground water, not surface level water in the pond. “Our treatment plants pull water from the aquifer and we’re influenced by Morses Pond, but it’s not Morses Pond water—it’s the ground water underneath Morses Pond that we pull into the well,” he said. “The samples that we take are taken from the finished water after it’s been treated.”
The DPW has no plans to test water in the pond, and the Massachusetts Department of Environmental Protection (DEP) hasn’t indicated there’s any need to do so, Cohen said. The DEP is more worried about a lifetime of ingestion, not bathing or swimming in water that may have elevated PFAS levels, he said.
Asked for a timeline of resolving the situation, Cohen estimated it could take anywhere from a few months to a year.
One possible solution is an industrial-sized carbon filter system consisting of 10- to 15-foot tall canisters that could start as a temporary solution but be part of a longer-term one. “The technology may be very straightforward. The challenge will be having the right design for our treatment plant, sourcing it, and procuring it,” he said. Sourcing could come to a supply issue, while purchasing will involve exploring all funding options. Hopefully the town can get a chunk of the $2M in funding that the Commonwealth this week announced to help public water systems in their PFAS responses.
As for how much a fix could cost, Cohen said the DPW has contingency funds that should help it get to a solution, though not necessarily implement one. A long-term system could cost anywhere from $1M to $5M based on what Wellesley has seen other communities buy or implement. So rate increases related to this are a possibility depending how much money needs to be borrowed.