Harpswell is seeking accountability and answers about PFAS pollution coming from the former Brunswick Naval Air Station after a spill of firefighting foam last summer.

In a February letter, the Harpswell Select Board asked the commissioner of the Maine Department of Environmental Protection who is responsible for testing waters affected by the spill. The board also said they would like to see all remaining foam removed.

Melanie Loyzim, commissioner of the Maine DEP, replied March 6 that the U.S. Navy will be responsible for monitoring pollution from the spill.

The U.S. Environmental Protection Agency, which is supervising the rehabilitation of the property through its Superfund program, has said it will ask the Navy to revise its testing plan to include the effects of the spill.

In November, the Navy said it had finished removing foam from the hangar where the spill occurred. The Midcoast Regional Redevelopment Authority, the public corporation responsible for the former base, recently said it plans to remove foam from two hangars on the north end of the property this spring.

Loyzim did not directly address the Select Board’s advocacy to remove the foam but wrote that her agency is seeking authority over foam removal at the property.

Meanwhile, the Maine Legislature is considering two bills on the matter, both co-sponsored by state Rep. Cheryl Golek, D-Harpswell.

One bill would prohibit the use of PFAS-containing firefighting foams at the former base. The other would establish a state program to collect and dispose of those foams throughout the state. Loyzim has estimated that the latter effort would cost about $5 million.

More than 50,000 gallons of water mixed with firefighting foam spilled from an aircraft hangar on the former base in August 2024 after an equipment malfunction. The PFAS chemicals in the foam are linked to cancers, changes in child development and other health concerns.

PFAS is an abbreviation for perfluoroalkyl and polyfluoroalkyl substances. The chemicals move easily through water and degrade slowly, if ever, giving them the nickname “forever chemicals.”

Testing over the last decade has found PFAS in water and fish on the former base, and in shellfish at the head of Harpswell Cove. The body of water borders both Brunswick and Harpswell. It lies south of the base, alongside the northeast corner of Harpswell Neck.

Last August, the Maine Center for Disease Control and Prevention warned people not to eat fish caught in Picnic Pond, Merriconeag Stream or Mere Brook — all of which feed Harpswell Cove — because of elevated PFAS levels. That decision was based on samples taken before the foam spill.

Three weeks after the spill, the Maine DEP conducted tests at the head of Harpswell Cove and found that the amount of one PFAS chemical, PFOS, was 70 times higher than it had been two years earlier.

David Page, a retired Bowdoin College chemist, said PFOS levels in that area of the cove make it unsafe for kids to swim in under standards set by the EPA. Page is a member of an advisory group helping to guide the former base’s transition to civilian use.

Scientists from the Friends of Casco Bay and Bigelow Laboratory for Ocean Sciences also have been testing water at sites from the head of Harpswell Cove to the Cribstone Bridge since the spill. They found that the combined amount of eight PFAS chemicals at the head of Harpswell Cove is nearly 10 times what it was before the spill.

Their data also shows how PFAS chemicals move through the water. Levels at sites closest to the former base were highest five and a half weeks after the spill, while levels at the most southern site were still rising at seven and a half weeks.

The amount of PFAS more than tripled in waters near the Cribstone Bridge, but it was about 1% of the amount at the head of Harpswell Cove. Those levels are well below the cutoff for safe swimming.

Heather Kenyon, of the Friends of Casco Bay, said that fits with scientists’ understanding of how pollutants travel. She expects PFAS concentrations to return to pre-spill levels at all sites with time.

The organizations have stepped up monitoring at sites near Harpswell and Brunswick since the spill. Last summer and fall, they collected sediment and shellfish samples, in addition to water samples, to test for PFAS. Results of their other testing are not yet available.

They plan to continue sampling this spring. They will add sites in Long Reach to understand if PFAS is entering that body of water and potentially affecting aquaculture there.

The Navy tests water at sites on its former base as part of its ongoing responsibility for pollution remediation. It has been testing for PFAS since 2022, and specifically for PFOS and another chemical, PFOA, starting in 2024, after the EPA added them to its list of hazardous chemicals.

Page said the Navy published fish sampling data in 2023 to support the Maine CDC’s warning about eating fish, but it has not released water sampling numbers.

“The lack of data should concern us all,” Paul Ciesielski told the Select Board at its Feb. 13 meeting. Ciesielski is Harpswell’s representative to the Midcoast Regional Redevelopment Authority’s Restoration Advisory Board.

Ciesielski suggested that the town find ways to pay for its own water sampling, perhaps by using funding currently allocated for testing wells at George J. Mitchell Field, the former site of a Navy fuel depot that supplied the base. One well at Mitchell Field, which fed the Harpswell Community Garden, tested positive for PFAS and is no longer used.

Friends of Casco Bay and Bigelow plan to sample water in Middle Bay at two places south and one place north of the jetty that juts out from Mitchell Field.

Sam Lemonick is a freelance reporter. He lives in Cundy’s Harbor.