The US Department of Health (CDC) in the US state of Maine is advising the public against eating freshwater fish from four nearby bodies of water after firefighting foam containing harmful PFAS chemicals was accidentally released at the former naval airfield in Brunswick earlier this week.

The public should limit or avoid consumption of freshwater fish from Mere Brook, Merriconeag Stream, Picnic Pond and the so-called Site 8 Stream northeast of the Brunswick Executive Airport runway.

The new warnings are based on historical data collected before Monday’s spill, the CDC said. Fish samples were taken as early as October 2023 and the data was shared with state health officials last spring. The CDC found elevated PFAS levels in that historical data and said the recent environmental accident is not expected to impact the new warnings released Friday.

The public should also stay away from the foam and avoid swimming and boating in these waters, the CDC added.

Meanwhile, cleanup work continues on the site of the former naval base and in the surrounding area.

Contractors will clean the buildings, including Hangar 4, where the firefighting foam known as AFFF was concentrated, the Maine Department of Environmental Protection said Friday afternoon.

Surface water samples will be taken every day for the next week. DEP continues to believe the recent oil spill will not impact nearby wells.

“We understand the community’s concerns about the visibility of the foam,” the department said in a statement. “The Maine DEP and Environmental Protection Agency have been investigating the former Brunswick Naval Air Station for 30 years and are familiar with the hydrogeology of the site. Although there is a history of PFAS contamination at the site, the DEP continues to believe that the recently released material will not impact nearby wells. The Brunswick-Topsham Water District has confirmed that the public water supply was not impacted by this incident.”