Chatham Targets $2.5 Million To Treat PFAS In Two Town Wells

CHATHAM – Voters will be asked to appropriate $2.5 million at the May annual town meeting to treat so-called “forever chemicals” in two South Chatham wells.

 The two drinking water wells, numbers 10 and 11, are located off Mill Hill Road. Levels of per- and polyfluoroalkyl, or PFAS, in well 10 have been consistently higher than the 4 parts per trillion federal limit, while well 11’s water has tested below the limit. Currently water from the wells are blended to reduce the PFAS level to below the federal limit.

 The goal, Leah Stanton of consultant Wesson and Sampson told the select board Oct. 21, is to have both wells in compliance when the federal limit becomes mandatory in 2031. 

 Both wells are “an integral part of us meeting summertime demand,” she said. Since both wells draw from the same source, it is likely that running just well 11 would result in the PFAS levels in that well climbing, she said. 

 After examining several options, two alternatives were developed. One involves building a new treatment plant like the $18.2 million one opened last summer for two wells off Training Field Road that also had high PFAS levels. The plant would also treat iron and manganese, which Stanton said can sometimes “get in the way” of treating PFAS. It would, however, allow both wells to be used year-round. The cost was estimated at $16.2 million.

 The second option was treating the PFAS with two 12-foot granular activated carbon vessels that would be used during peak summer water demand. The vessels would not require a separate building but could be mounted on a concrete pad outdoors. However, it would necessitate shutting down one or both wells during the off-season and would not treat iron and manganese. But the cost would be significantly lower, estimated at $2.5 million, and if further treatment was deemed necessary, the treatment vessels could be repurposed in a new building, Stanton said.

 In response to a question from board vice chair Cory Metters, Stanton said there is new technology for treating PFAS “on the horizon.”

 “It is changing very rapidly, but this is a tried and true technology that we’re using now,” she said. Shutting down wells 10 and 11 in the off-season would not be a problem, she added; the other town wells provide adequate capacity for the town’s needs most of the year, except the summer.

 Protecting drinking water should be “our number one topic,” Metters said, “because without it all the other topics can just go to heck.” However, he added that he was “not overly eager to spend $16 million” and endorsed the $2.5 million option. 

Other board members agreed, and asked staff to develop an article seeking the funding at the May annual town meeting.

Public Works Director Rob Faley said the town has $1.1 million in PFAS settlement funds that could be tapped for the project.