Water staff outlines PFAS treatment system for Well 15; town to use retained earnings to fund equipment

The committee heard March 5 from a water department representative that the town is building a PFAS treatment system for a public supply well (Well 15) where tests exceeded state and federal guidance. Mark Willette, speaking for the water side, said the underground piping work is nearly complete, equipment has been contracted from ECT in Portland, Maine, and the town expects to assemble and test the system in the spring.

Willette presented cost estimates for the treatment system prior to any building: about $1.4 million for equipment and shipping, $450,000 for site work, $100,000 for engineering and roughly a 20 percent contingency (~$390,000), for a subtotal of approximately $2,340,000. He said a building to house the equipment would add roughly $1.4 million to $1.6 million, bringing the total project cost to about $4,000,000. "The water commission has voted to use retained earnings. We have close to $12,000,000 in retained earnings," Willette said.

Willette said the town discovered PFAS levels above the combined benchmark for the six PFAS compounds used by DEP and EPA. "When you add all of those together, the sum of those 6 cannot be over 20 parts per trillion," he said, describing the regulatory threshold and explaining that the well cannot be returned to service until treated.

The committee heard a timetable: equipment will arrive on tractor-trailer trucks from Portland and the town hopes to have the system assembled and tested by May, with startup contingent on lab results and commissioning. Willette described the treatment technology as ion-exchange resin in canister-style filters. He said resin replacement and disposal are recurring costs: resin changeouts are anticipated every three to four years and current replacement-and-disposal costs are on the order of $400,000 per replacement (new resin plus disposal to an approved hazardous-waste facility), though those costs could change.

Willette also described redundancy and operations: the design includes multiple canisters so the treatment can be rotated and backup canisters and big bags of resin will be stored on site. He said the town is piping other nearby wells into the future treatment location so they can be routed through the system if needed.

Committee members asked about operations, training and backup power. Willette said ECT assembled systems elsewhere, will provide on-site start-up support and training, and that the town is evaluating whether its backup generator can power the treatment system.

The presentation was informational; the Water Commission has already voted to use retained earnings to pay for the system, and no committee vote was recorded at the March 5 meeting.