MIDDLEBORO — The Department of Public Works opened a free drinking water filling station at its 65 Sachem St. headquarters last week — marking another step in the town’s multimillion-dollar effort to address PFAS, or “forever chemicals,” in the municipal water supply.

The station is open to all Middleboro residents and provides drinking water with PFAS levels below the federal standard of four parts per trillion — and often with no detectable PFAS at all, according to Water Superintendent Mike Bumpus.

The station is open from 7 a.m. to 3 p.m. Monday through Thursday, and from 7 to 11 a.m. on Friday. Town Manager James McGrail encouraged residents to bring clean, reusable containers to avoid any cross-contamination and reminded the community to continue practicing water conservation.

The water available at the station comes from the DPW’s treatment system and is regularly tested to ensure it meets federal standards for PFAS.

While the U.S. Environmental Protection Agency recently set the allowable limit for PFAS in drinking water at four parts per trillion last year, Massachusetts currently uses a more lenient standard of 20 parts per trillion. For context, four parts per trillion is roughly equal to four drops of water in 20 Olympic-size swimming pools.

The low or undetectable PFAS levels at the new filling station contrast with the East Grove Well — the site of a $33 million project to build a new treatment plant to address consistently elevated PFAS levels.

Testing conducted on July 7 and reported by the Massachusetts Department of Energy and Environmental Affairs showed PFAS levels at East Grove at about 27 parts per trillion. While the well is used as little as possible, it was brought online on Friday, July 25, to supplement municipal supply.

Residents were notified through the town’s alert system that the well was in use. Anyone wishing to receive these alerts can sign up through the “Notify Me” page on the Town of Middleboro website.

In the past, residents received letters from the town when PFAS levels at East Grove exceeded the state standard, but no letter was sent after the July 7 test. That’s because violations are determined by quarterly averages — not single monthly results. For the town to issue a formal notice of violation, PFAS levels would need to exceed the state standard for three consecutive months.

The July 7 test is the first elevated result for the current quarter. The next test is scheduled for Aug. 5, and the September test has not yet been scheduled. If both upcoming tests show elevated PFAS levels, a violation notice will be sent to residents.

Bumpus said the East Grove Well was activated to supplement the water supply while other wells were shut off temporarily to recover. Many of the town’s wells are currently running at or near their maximum daily capacity, with some operating up to 20 hours a day.

Although PFAS levels are high at the East Grove source, Bumpus said the water is blended with lower-contaminant water from other wells before it reaches homes, reducing PFAS concentrations to levels below state and federal limits.

So far this year, the East Grove Well has contributed less than 1% of the town’s daily water totals.