Installing a new system to chlorinate the town’s public water supply may not be as costly as first thought. But the final price tag will depend on whether the town chooses a solution that will also treat for PFAS (per- and polyfluoroalkyl substances). PFAS remediation equipment would require building a larger facility than the current underground vault, bringing the estimated cost of the project to $1.8 million. On the other end of the spectrum, a system that simply met the Department of Environmental Protection’s chlorination requirements could cost as little as $60,000, according to engineering firm Tighe and Bond.
Last summer, coliform bacteria contamination in both town wells on Pond Road forced the town to shut down well #2 and begin emergency chlorination of well #5. Tighe and Bond was hired to design what the town thought was a temporary solution to bring well #2 back online as well as a long-term solution.
But at the Water Commission’s Feb. 16 meeting, when Chair Cindy Russo asked if anything beyond the temporary solution was really necessary, Tom Mahanna, Tighe and Bond vice president, said: “That’s the only thing you’re required to do.” He added that DEP doesn’t care if the town builds a larger facility or treats for PFAS, as long as levels stay below DEP’s minimum contamination level of 20 parts per million (ppm) for the sum of six specific substances.
When the state mandated quarterly PFAS testing in 2020, the level detected in well #2 was 6.7 ppm; well #5 tested at 15.2 ppm. The blended water from the two wells was 8.28 ppm. Levels in both wells decreased steadily after that, and Department of Public Works Director Tim Kilhart told the committee January’s PFAS test results showed no PFAS detected in well #2, and 7.7 ppm in well #5.
Mahanna said that while PFAS levels in town water are currently in DEP’s acceptable range, the town might want to set a lower maximum level. He said it all depends on the community’s goals and what residents can afford. In addition to the cost of building a larger facility, operating costs are “extremely expensive,” Mahanna said. Currently DEP requires specialized testing to determine if the medium used to remove PFAS is working, and those tests are costly. In addition, the medium needs to be replaced and properly disposed of when it breaks down. Replacement time varies with different water systems, but when designing a system, Mahanna said his firm tries to use a medium that will last at least a year.
Satisfying minimum DEP requirements
Mahanna said there is enough space in the existing underground vault near the wells to house the necessary equipment to bring well #2 back online. Larger pipes that will allow chlorine to stay in contact with water leaving the wells for a longer period of time have already been installed under Pond Road. An analyzer and some additional plumbing will be needed to make the system fully automatic, along with further testing.
In addition, at least one more Department of Public Works employee will need to get a “tier 1” license that allows an operator to put chemicals into the public water supply. Currently, only Kilhart has that license, but because the town is still operating under DEP’s emergency protocol, another water system operator is allowed to chlorinate the water. Kilhart told the Press that daily chlorination is required, and union regulations prevent him from working on weekends, so a second operator is currently doing that work and getting paid overtime. That has already increased the water system’s operating costs.
Mahanna told the committee it would take an additional $60,000 to complete the work to bring well #2 back online. He also provided a second alternative to the liquid chlorine system currently being used—a tablet system, which is easier to use and leaves less room for operator error. He said the only caveat is that the tablet system would require a new permit, and the town would have to prove that it worked before DEP would accept it as a final solution. Russo asked him to provide a cost estimate for that system.
Mahanna stressed that something needs to be done about well #2 now. “You can’t keep using the emergency process,” he said, and having only one operational well is risky—there’s no redundancy should anything go wrong. Tighe and Bond engineer Mary Danielson pointed out that relying on well #5 to stay below the PFAS maximum contamination level introduces another level of risk. Well #5 has always tested higher than well #2; blending the water of both wells would help keep levels below state requirements.
Is the minimum good enough?
Kilhart expressed concern that when the wells were contaminated, DEP wanted both a short-term and long-term solution. The town’s short-term solution was the one that now appears as if it will satisfy the DEP; its long-term solution was to build the new facility. He asked if DEP would accept the short-term solution as the final one. Danielson said it would because DEP asks for both long- and short-term solutions as a way to help towns figure out what to do, not to dictate the solution.
Russo asked what other advantage building a new facility might have besides PFAS remediation. Mahanna said without it, the town might not be able to address other possible changes in water quality, such as hard water due to high levels of iron and manganese, although current levels of those substances in town water are fairly low.
Should the town decide that it wants to build the larger facility, low interest loans are available from the state’s Clean Water Trust fund. Mahanna said the town should submit an application this August, since being accepted does not mean a commitment to do the project. If the town were selected and wanted to move ahead with the new facility, it would need to approve the borrowing at 2023 Town Meeting and submit a second application in October. That would likely push the project completion date into 2025, Mahanna said. The cost of the August application would be about $10,000.
Bragan reminded the committee that a few months ago the Select Board said it wanted to add PFAS remediation to the water system plans, and the DPW director said he wanted to add water softening. At the time, Russo said, “We all thought it made sense, but it may no longer make sense because we’re not finding problems.” The committee was scheduled to continue the discussion at its Feb. 23 meeting before providing a recommendation to the Select Board on March 1.
