The Maine Department of Environmental Protection will be reaching out to some Brunswick residents this week to test private wells in the wake of the Aug. 19 firefighting foam spill.

The DEP will be going door to door this week at homes on Coombs Road from the intersection at Gurnet Road up to roughly a quarter mile past the intersection with Hawkins Lane. It said that it will include properties on Hawkins Lane and Purinton Road.

“Approximately 45 residential properties have been identified by the department for sampling,” the Department wrote in a Saturday news release. “DEP staff will leave contact information if the property owner is not home so that follow-up can take place.”

The DEP clarified last week that those living within this boundary could be eligible for PFAS sampling and reimbursement in the midst of ongoing remediation at Brunswick Landing. It did note, however, that homeowners should reach out sooner rather than later, as reimbursement funding is limited.

The DEP’s reimbursement program will give $300 to qualified homeowners who conduct PFAS testing of their wells at a state-certified lab. That testing can cost between $250 and $400, depending on the test materials used and the requested turnaround time. Some scientists and local environmentalists have suggested those who do not qualify for reimbursement to try using cheaper at-home test kits to do an initial screening.

Over the weekend, the DEP also released new sampling results, which showed an increase in PFAS levels where foam removal efforts are taking place. The department said these results are most likely due to the fact that the natural flow of surface water and removal efforts are drawing contaminants to remediation areas, such as the outlet of Picnic Pond.

One particular area at a salt marsh near Harpswell Cove also saw increased PFAS levels from earlier testing results, which the DEP said could be the result of “residual contamination” that moved to the area through natural means, such as tidal cycling and water flow.

Results also showed a decrease in PFAS levels in water sources near the original spill site at Hangar 4 at Brunswick Executive Airport, where 1,450 gallons of AFFF — a PFAS-containing firefighting foam — was spilled with 50,000 gallons of water on Aug. 19. The hangar, which is owned by the Midcoast Regional Redevelopment Authority, has since been decontaminated, MRRA Executive Director Kristine Logan told the public at a Brunswick Town Council meeting last week.

Logan also said in a recent guest column that planes and TechPlace industrial spaces have been decontaminated. She also noted that the stormwater drains in the hangar have been jetted and the water from the decontamination process has been collected and stored for disposal.

The Navy, she said, is scheduled to remove the remaining foam at Hangar 4 on Sept. 16 as part of a requirement to remove foam from its systems by Oct. 1.

The DEP reiterated that public drinking water is safe to drink and to stay away from foam if spotted. It also said the next update would come when additional test results are available.

For more information and resources related to the AFFF spill, visit brunswickme.gov/761/Brunswick-Executive-Airport-Firefighting.