A new proposal from the U.S. Environmental Protection Agency to crack down on per- and polyfluoroalkyl substances, commonly known as forever chemicals, in drinking water has some Island water departments preparing for extensive testing and treatment of public water systems.

The proposal, which is the first major step the Biden administration has taken to address increasingly high levels of six different PFAS chemicals in drinking water, sets the national standard well below the current Massachusetts state regulations, potentially triggering changes to Island water systems.

The proposed standard from the federal government would set a new, nationwide limit of four parts per trillion for two of the compounds, and create an additional case-specific regulation for four other PFAS chemicals.

One of the Island’s largest public water wells, located off of Barnes Road at Lagoon Pond, is managed by the Oak Bluffs water district. The district most recently tested the well’s PFAS levels at around nine parts per trillion. The amount safely complies with the Massachusetts threshold of 20 parts per trillion — one of the strictest in the country — but would not be in compliance under the new proposed standard.

But Greg Dankert, assistant superintendent at the Oak Bluffs water district, said that this comparison can seem more shocking than it really is.

In the past, the six PFAS chemicals were measured as one mixture, he explained. Since the EPA is requiring only two of the compounds, PFOA and PFOS, to meet the 4 parts per trillion maximum, it’s misleading to compare it with previous testing levels. New testing would need to be done for just the two chemicals for experts to get an accurate read of how the well’s contamination levels match the new potential regulation.

“It was obviously concerning everybody last week when it was announced because our new PFAS level is just over nine and now they’re proposing four, putting us at five parts over,” said Mr. Dankert. “But they’ve split off two of those contaminants from the original six, so we should get different results in the future.”

According to the proposal, levels of the four remaining chemicals will be measured with a specific hazard index equation. The calculation will help experts determine if the mixture poses any serious health risks.

In a Zoom meeting last week, Mr. Dankert and other representatives from water departments across the country met with EPA officials to discuss PFAS treatments and funding for remediation efforts. Mr. Dankert said there seems to be plenty of money to help fix any problems thanks to the Bipartisan Infrastructure Law.

Neither Edgartown or Tisbury have detected PFAS in their public water wells, according to recent data from the Massachusetts Office of Energy and Environmental Affairs. But Bill Chapman, water superintendent at the Edgartown water department, says he’s still keeping a close eye on the proposal.

“If you detect even the most minute trace [of PFAS] you have to report it,” he said.

Thanks to a record of clean water samples the department is currently on a waiver, which means it likely won’t need to test for PFAS again until 2025. Ultimately, though, the department is at the will of the Massachusetts Department of Environmental Protection (DEP) which strictly follows EPA developments, added Mr. Chapman.

Water officials in West Tisbury, Chilmark and Aquinnah did not respond to requests for comment this week.

The EPA’s proposal targets only public water systems, but detection of PFAS in private wells on the Island has sometimes given water departments an extra reason to test public ones.

Five years ago West Tisbury discovered PFAS contamination at the Martha’s Vineyard Airport and in local private wells near the area. After the culprit was identified as a PFAS-laden firefighting foam, the Edgartown water department decided to conduct PFAS testing, concerned about the downgrade from the airport to one of the town’s public water sources.

Standard PFAS water contamination testing is usually done annually, but with more regulations on the horizon it’s likely that testing could happen twice a year or quarterly.

Even if the proposal isn’t approved, Mr. Dankert said that the Oak Bluffs water district may consider quarterly testing because of result variability with the Island’s seasonality.

“We’ve seen such different results with different quarters,” he said. “This time of year we’re not pumping much water but in the summer we ramp up six or seven times what we’re doing now.”

The six PFAS chemicals identified by the proposal are among thousands of others commonly detected in air, clothing, food and water that go unregulated and can infiltrate human blood streams and potentially pose serious health issues.

The chemicals, which have been linked to liver problems and increased risk of some types of cancer, can be found in everything from waterproof clothing, cookware and upholstered furniture and are increasingly found as testing becomes more widespread.

“The worst thing about PFAS in drinking water is the fact that there’s still a lot of unknowns,” said Mr. Chapman. “We adhere to regulations and, yes, we’re water professionals that want it to be contaminant-free. But the simple truth is most people are exposed to PFAS more through other everyday living than just by the water they drink.”

Mr. Dankert anticipates that more restrictions on drinking water will be created in the future and, though concerned about the water district’s ability to keep up, feels that it is essential to prioritizing public health.

The sentiment is shared by the state’s DEP director of public affairs Edmund Coletta, who issued a public statement that the department “applauds the U.S. EPA for releasing its proposed drinking water regulations... and will evaluate the impacts of the new draft values as EPA works toward a final rule.”

The EPA will host an online public hearing on May 4 to receive feedback on the proposal. For more information about PFAS and the upcoming hearing, contact PFASNPDWR@epa.gov.