Martha Spiess, Eric Perkins of the Midcoast Regional Redevelopment Authority, and Jason Prout and Mike Jouver of the Brunswick Sewer District sample a separator pit just outside of Hangar 6 on Nov. 26, 2024. Courtesy of Ed Friedman

A citizens group’s testing revealed that sewer water flowing from Hangar 6 at Brunswick’s airport has high levels of harmful per- and polyfluoroalkyl substances, better known as PFAS.

Friends of Merrymeeting Bay conducted testing on Nov. 26. The tests detected high levels of a particularly toxic PFAS chemical compound known as PFOS. The update comes the same day the owner of the hangar, the Midcoast Regional Redevelopment Authority, sent a letter to the town stating that tanks that stored the chemicals were not leaking.

PFOS is a compound known to be harmful to human health and is found in high levels in aqueous film-forming foam (AFFF). Brunswick Executive Airport’s Hangar 4, which is owned by the Navy but operated by MRRA, dumped 1,450 gallons of AFFF concentrate mixed with 50,000 gallons of water on Aug. 19, 2024.

The spill prompted ongoing cleanup and monitoring efforts as well as a push to get rid of the foam at the airport. Concern has grown around Hangar 6, which some have speculated is leaking harmful chemicals based on the testing data around the airport that Friends of Merrymeeting Bay has collected over the years. The sewage that flows out of Hangar 6, which is not treated for PFAS, ultimately flows into the Androscoggin River.

Testing from November, which was conducted with the Brunswick Sewer Department using Cyclopure water test kits, showed that five sewer locations were sampled near the hangar and close to the airport. At the first location, known as the Navy Meter, Cyclopure tests detected 1,494.7 parts per trillion of PFOS. In total, it detected 2,029.2 parts per trillion of various PFAS compounds.

Tests at another sample location, labeled as Hangar 6 West on the testing data sheet, detected 11,277.4 parts per trillion of PFOS and 56,508.9 parts per trillion of PFAS.

The remaining locations also showed PFOS levels ranging from 666.9 parts per trillion to 3,000. Total PFAS detected at all sample locations were well over 4,000 parts per trillion.

The state’s interim drinking water guideline is set to 20 parts per trillion, though the Environmental Protection Agency has guidelines that say that any exposure to ultra-harmful compounds like PFOS above zero parts per trillion can be harmful. Currently, Maine has no surface water limits on PFAS and the river is not considered potable, according to Portland Press Herald reporting.

General Manager Rob Pontau of the Brunswick Sewer District said that the PFOS levels in Hangar 6 are concerning, but they do not effect the wastewater treatment process. Flow from the hangar is “significantly diluted” once it reaches the treatment plant, so Pontau said that numbers are approximately 300 part per trillion in the influent flow.

“I’m not saying it’s acceptable, no PFAS is the goal,” Pontau wrote in an email to The Times Record. “Unfortunately, much of what gets discharged from Hangar 6 passes through the treatment plant and goes directly into the river. As I’ve stated before, PFAS treatment of wastewater is barely feasible and cost prohibitive. That’s why we must eliminate it at the source and stop producing and using this substance.”

‘No leak’

MRRA forwarded a letter to the town Tuesday morning, which Town Manager Julia Henze provided to The Times Record, that detailed a walk-through with the Fire Department of the hangars last week. Deputy Chief Josh Shean of the Brunswick Fire Department said that he was present for most of the walk-through with Poole Fire Protection except for the portion that viewed Hangar 6, due to time constraints.

MRRA’s Interim Executive Director Steve Levesque said that the town had requested a third-party verification of Hangar 6 to assure there were no leaks happening.

Speculations about the risks, including alleged leaks, the hangar posed to the public had risen after Hangar 4’s fire suppression system malfunctioned and spilled. The situation prompted the Town Council to press MRRA to shut off the fire suppression system in Hangar 6 in the fall, which the MRRA board ultimately opted not to do, and to hire an outside specialist to look into a short-term protection plan for the hangar.

Last week’s Hangar 6 walk-through was conducted by Poole Fire Protection — a third-party company hired by MRRA to assess risk and gauge solutions to the AFFF situation as well as find the root cause of the spill. Levesque said the risk assessment should be complete in a few weeks, while the root cause analysis is still ongoing.

Poole’s letter detailing the walk-through stated there was no sign of an AFFF leak based on observations at the hangars.

“Hangar 6 had one AFFF foam concentrate tank, and it was approximately 30% full. There has been no evidence of AFFF foam concentrate loss or usage, based on the markings on the concentrate tank since the last marking in August 2024 (approximately 5 months),” a representative for Poole Fire Protection wrote in the letter. “Therefore, if it [were] my opinion, based on my field observations, there are no AFFF concentrate leaks in Hangar 6.”

The letter also noted that the assessment discovered a small leak at Hangar 5 at the foam pump system piping, and a “minimum AFFF foam concentrate was being captured in spill absorbent.” Poole described the leak as “minor” and located at the 1/4-inch connection for a pressure gauge that appeared from corrosion. It said that it was not near a floor drain and that the repair was scheduled for Tuesday, and Levesque confirmed Wednesday that the repairs were completed.

As for the PFAS levels in the sewer water, Levesque said that there could be residual PFAS in the water and oil separator system stemming from an incident in 2012 that released 2,000 gallons of AFFF from the hangar. He said that the residual PFAS flow into a “sanitary sewer system as designed by the Navy.”

“We believe this was activated by recent aircraft washing in the hangar itself, which flows to the designed system,” Levesque said, adding that the hangar was an “epicenter of historical AFFF training” for the U.S. Navy before the hangar was built.

He said that floor drains are connected to the oil/water separation system which then flows into the sanitary sewer system. He said that no wastewater goes into the storm drain system.

“We were waiting for our sampling to be completed to determine its scope,” Levesque said, noting that MRRA had worked with Brunswick Sewer District and Friends of Merrymeeting Bay on the sampling. “Now that we have it, we are currently working with Clean Harbors to clean out any residuals in the [oil/water separator].  The work should be completed within a week or so.”

The hangar was part of a Navy 731-acre property transfer that included airport land and several buildings. The process to transfer land back to the public was initiated in 2011, when the Navy closed its Naval Air Station. MRRA was formed by Maine statute to redevelop the land, known as Brunswick Landing, back into public use.

Friends of Merrymeeting Bay volunteer Martha Spiess holds an oily sample from Hangar 6. Courtesy of Ed Friedman

Historical testing

Friends of Merrymeeting Bay has been testing water sources around the base and elsewhere in town for PFAS for a couple years, according to organizer Ed Friedman.

Friends of Merrymeeting Bay also tested Hangar 6 on July 29 using Cyclopure and Alpha Analytical, a certified lab in Environmental Protection Agency testing methods for PFAS, to compare samples. Cyclopure results showed 23,927.9 parts per trillion of PFAS while Alpha Analytical detected 29,687.2.

MRRA also released a statement in December, noting that it would only be sharing certified lab results for PFAS testing as the Maine Department of Environmental Protection continues its monitoring in the area following the spill.

“Results from non-certified sources may not meet established standards and could present a risk of misleading or inaccurate information,” the organization stated on its website. “Certified laboratory reports ensure that testing methods and results are reliable, consistent, and in line with state and federal guidelines.”

Cyclopure said that its data collection process is the only reason it does not have an EPA certification. While it acknowledges that the EPA methods are designed to create a common basis of comparison between labs and test results, Cyclopure is not EPA certified because it does not require water samples from customers. Cyclopure customers instead send the filter that the water passed through to the lab for testing. The company described it as a “Polaroid” of the PFAS compounds found in the water at the time of sampling.

While official entities like the DEP utilize EPA-certified labs for PFAS testing, some Maine scientists and environmentalists have pointed to Cyclopure as a good way to get a sense of what’s in drinking water.

Henze also said at a town meeting on Monday that the water samples that Friends of Merrymeeting Bay took at the hangar will be available on the town’s webpage.