The Maine Department of Environmental Protection has announced that PFAS levels near the Aug. 19 accidental discharge of firefighting foam at the Brunswick Executive Airport are decreasing.

DEP released results of water samples taken from Harpswell Cove and draining systems above the cove. The samples were taken the day of the release, three days after the release, and one week after the incident.

“These results show that PFAS concentrations are decreasing in the upper portions of the surface water drainage, closest to the release location,” DEP officials said in a statement.

A fire suppression system accidentally discharged the foam on Aug. 19. The incident released 1,450 gallons of foam mixed with 50,000 gallons of water. The foam contains dangerous chemicals known as PFAS, which have been linked to various forms of cancer and other health problems. 

The new sample data also showed an increase in PFAS concentrations farther along the drainage system, “particularly at the outlet of Picnic Pond, most likely due to the fact that removal efforts and natural flow paths are drawing the foam to these locations.”

The results also showed increased PFAS levels in the salt marsh above Harpswell Cove.

“This is likely to represent residual contamination that migrated to this area which is moving slowly through the system due to tidal cycling and natural flow,” DEP officials wrote.

Officials said that the Brunswick Landing water supply is confirmed safe to drink. 

Next week, DEP officials will be reaching out to some homeowners along Coombs Road from the Gurnet Road intersection to past the intersection with Hawkins Land, along with parts of Hawkins Land and Printon Road. Officials will request samples of local drinking water for testing. 

Results from other samples taken from Harpswell Cove should also be available next week.