Suffolk County bans fishing at Swan Pond in Calverton over PFOS finding

A Suffolk County pond near a U.S. Navy-contaminated former Grumman site in Calverton contains freshwater fish that have tested positive for high levels of the forever chemical PFOS, according to county officials, who recently ordered "No Fishing" signage placed at a boating entrance to the property.

The signage at Swan Pond on county parkland follows Navy testing of fish in the pond conducted in November and December 2024, according to a copy of the results, which were recently released to the county, Suffolk officials said Thursday. The state has previously cautioned anglers from eating fish from other nearby waterways associated with the former Grumman plume, but not Swan Pond.

Separately, the state Department of Environmental Conservation has taken down a Swan Pond website that details fishing opportunities and access at the site. The DEC, in a statement, said it's working with Suffolk County and other agencies to "protect public health and safety" by developing information, "including updated website content, to advise anglers that fishing is not allowed in the pond at this time."

In a statement Thursday, Suffolk County Executive Edward P. Romaine spokesman Michael Martino said, "Only days ago, Suffolk County was informed by the Navy that fish in Swan Pond tested positive for PFOS contamination, results the Navy had known for 18 months. Based on those findings and in coordination with the state DEC, the county took immediate action to prohibit fishing in the pond."

Martino added the public "deserves timely transparency and decisive action when health and safety are at risk."

Suffolk County has conducted its own tests of fish in the pond, according to Martino, and expects to release its findings when results are in. He said county and state officials have met weekly with the Navy about the site, including on Thursday.

The Navy controls the former Grumman site on property that is now the industrial park EPCAL.

In an emailed statement, Navy spokesman David Todd confirmed the agency conducted surface water, sediment and fish tissue sampling for per- and polyfluoroalkyl substances at Swan Pond. “This was an area that was not previously investigated,” he wrote.

“Preliminary results show that some adult fish tissue samples exceeded New York State’s 2025 ‘Don’t Eat’ fish consumption advisory level for” PFOS, he said. “Because consuming fish with elevated PFOS levels may pose health risks, the Navy shared these early findings with state regulators and local stakeholders, including Suffolk County.”

Todd emphasized the results “are not final.”

“Data interpretation is ongoing and will be incorporated into the final remedial investigation report,” he wrote. “The Navy will also discuss the findings and next steps at upcoming Restoration Advisory Board meetings. This information will support continued collaboration among [the state DEC and Department of Health] and the Navy to determine actions needed to protect human health and the environment.”

He said residents with questions about health risks from consuming fish from the pond should contact Suffolk County or the state Health Department.

The pond is adjacent to the Swan Lake Golf Club and incorporates a small fishing boat launch for anglers to fish for largemouth bass, chain pickerel, bluegill, pumpkinseed, black crappie, yellow perch and brown bullhead.

A copy of the Navy results show all 17 adult fish tested in the sample had more than 10 parts per billion of PFOS, from 13.7 parts per billion to 60.6 parts per billion. The state recommends limiting consumption of PFOS-tainted fish to one meal per month when contamination reaches 10 to 40 parts per billion. Fish above 40 parts should not be eaten. Four samples of bluegill contained 42 to 60.6 parts per billion. Fish under 10 parts per billion should be limited to four meals per month.

Last year, the Navy released data that showed contaminated water is actively migrating from the site of a former fire-training area on the property toward Swan Pond, as well as adjacent Donahue’s Pond and the Peconic River. High concentrations of PFAS in that area may be linked to firefighting foams once used there, Newsday has reported.

Navy groundwater maps at the time show the forever chemicals detected at 2,050 parts per trillion south of the training area moving toward the Peconic River, a figure well above the 2024-established EPA maximum contaminant levels for PFAS at 4 parts per trillion for drinking water.

Forever chemicals don’t break down naturally and exposure to them has been linked to decreased fertility, developmental delays, increased cancer risk and poor immunity.

In 2023, the state Department of Health warned against eating fish caught in Peconic Lake and the Peconic River because of PFAS contamination, Newsday reported at the time.

By Mark Harrington

mark.harrington@newsday.comMHarringtonNews

Mark Harrington, a Newsday reporter since 1999, covers energy, wineries, Indian affairs and fisheries.