The airport in Hyannis plans to expand. What's the strategy for PFAS contamination there?

Editor's note: The following corrections have been made from a previous version: the spelling of a last name; the amount the airport is contributing for the cost of PFAS treatment at Mahar wellfield; the decade aqueous film forming foam was patented; and a groundwater testing date. A clarification about contaminates reacting to groundwater rise and fall was added.

Grainy footage documenting an all-Cape fire training exercise at the Cape Cod Gateway Airport shows firefighters wearing black coats wrestling long hoses from red trucks towards the infernos they had set.

Some of the fires blazed on the ground, some in old-fashioned cars, one in a small building clad in Cape Cod’s classic shingles. All produced hurricanes of charcoal-colored smoke and jumpy orange flames.

As the fires burned, dozens of firefighters worked together to extinguish them, directing the fountains from their hoses at the flames, sometimes with U.S. Navy personnel looking on.

A few minutes in, the video cuts to a man in a white jumpsuit and cap wielding a smaller hose, connected to a red canister clutched in his other gloved hand. Clouds of white dust explode from the hose, blanketing a collection of flames before billowing into the sky. At one point, the man, whose suit bears the crimson logo of Ansul, a fire suppression company later purchased by Tyco Fire Products, sprays the canister at a pipe of fuel on fire — smothering the flames instantly.

Later, a firefighter joins with a helmeted workman wearing a gray jumpsuit bearing the company name Rockwood, possibly Rockwood Sprinkler Co., which developed a nozzle for use on Navy warships during World War II. Together, the men hold a hose that appears to cover a flaming car in a soggy foam.

The video, posted on YouTube by an account called “falmouthfiretraining” in 2011, indicates the training exercise took place in 1956 — the same year the Barnstable County Fire Training Academy opened its doors about a mile away.

The training exercise at the airport took place about a decade after the introduction of PFAS, or per- and polyfluoroalkyl substances. Airport staff noted in documents submitted under state clean-up rules, about a decade later the U.S. Navy, working with the company 3M, received a patent for aqueous film forming foam, or AFFF, a firefighting foam containing high concentrations of the so-called “forever chemicals.”

Interviews with airport staff indicate PFAS-containing firefighting foam - linked to health problems including breast and testicular cancer, reproductive problems, immunotoxicity in children and thyroid disease - was purchased as early as the 1980s, though records detailing the purchase of ChemGuard’s AFFF date back only to 2000.

The airport is dealing with the PFAS fallout as officials consider a plan to expand. Many worry how construction related to the expansion will affect the existing contamination.

Apart from real-life accidents, the foam was sprayed during annual testing required by the Federal Aviation Administration, and every three years during drills intended to prepare airport staff for emergencies, said Airport Manager Katie Servis.

As it did at the nearby training academy, the foam soaked into the soil.

And as happened at the fire academy, over time, the chemicals spread underground through the water contained in the region’s sole aquifer, essentially an underground glacial sandpile, eventually drifting across the airport’s property line towards public drinking water wells that serve Hyannis.

According to airport staff, PFAS from firefighting foam used at the airport — which has a unique “fingerprint” that distinguishes it from foams used at other nearby sites, including the fire academy —first reached the town’s drinking water wells in 2022, after PFAS treatment at the wells began.

“Of the three wells that are at Mahar (wellfield), only one of the wells is drawing in from our plume,” Servis said in a recent interview at the airport’s administrative offices. “Only one of them.”

The carbon filtration installed at the Mahar wellfield in 2020 is now serving two roles.

Though its initial purpose was to make Hyannis tap water safe to drink by filtering PFAS out of the groundwater pulled up by the wells, the carbon filter is now also the primary strategy for remediating the underground PFAS plume coming from the airport.

The airport, which is owned by the town but operated as a self-sustaining enterprise that doesn’t draw from town coffers, is contributing a lump sum of $477,000 for the cost of PFAS treatment at the Mahar wellfield, according to Servis.

“All of the water that's coming from this area is being drawn into the Mahar wells,” Servis said. “It's going to be treated at the Mahar wells, and then it's done.”

The airport has not drilled any monitoring wells beyond the Mahar wellfield, according to Bryan Massa, the licensed site professional managing the cleanup for Cape Cod Gateway Airport.

While PFAS from the airport will eventually travel beyond the Mahar wellfield to Mill Creek, Servis acknowledged, concentrations after the wells won’t surpass state standards that would require cleanup.

Servis noted that the Department of Environmental Protection “agreed that because there is a filtration system in place at the Mahar wells, that is an adequate level of treatment to account for the airport plume.”

Andrew Gottlieb, executive director of Association to Preserve Cape Cod, said the airport’s PFAS plan doesn’t serve the interests of residents, who want the harmful chemicals fully removed from the local environment.

“They're not cleaning up the plume,” Gottlieb said. “All they're doing is removing it from the water before it goes into the distribution system as fed to children and women of childbearing age. That's not a compliance strategy, that's not what the law calls for, it's lazy and they shouldn't be allowed to get away with it.”

Airport PFAS contamination by the numbers

The cleanup of PFAS plumes coming from the airport and nearby county-owned fire academy – both located near drinking water protection areas, neighborhoods and businesses – are being managed separately, though under the same state environmental regulation: the Massachusetts Contingency Plan.

The cleanup at the airport, now in its final phase, is moving through the state’s regulatory process faster than the cleanup at the fire academy, where regular training with PFAS-containing firefighting foam over the course of decades created a massive PFAS plume with groundwater concentrations that dwarf those reported at the airport.

In 2015, tests from one hotspot monitoring well at the fire academy showed groundwater concentrations of the six PFAS chemicals regulated by the state reached roughly 225,000 nanograms per liter, with more recent testing registering concentrations of roughly 4,500 nanograms per liter.

The state standard for PFAS6 in groundwater, instituted in 2019, is 20 nanograms per liter.

Massa noted the highest concentration recorded at the fire academy was almost 235 times higher than the highest concentration recorded at the airport, where testing has identified two primary locations where firefighting foam seeped into the ground.

Tests show that at the first airport hotspot, called the deployment area, groundwater concentrations of the six PFAS chemicals regulated by the state reached their highest concentration – 1,172 nanograms per liter – in May of 2020, according to Massa. Concentrations at the deployment area dropped by more than half to 570 nanograms per liter by December 2023.

At the second airport hotspot, groundwater was first tested in October 2020. At that time, tests showed concentrations of the six PFAS chemicals regulated by the state reached 44 nanograms per liter, Massa said. The most recent test there showed concentrations had dropped to 28 nanograms per liter – a roughly 36% decrease.

Airport staff largely attribute the drop in PFAS6 concentrations to the 2020 installation of caps that stop storm and rainwater from washing more of the chemicals through soil into the groundwater below the most contaminated parts of airport property.

But Gottlieb and others note that the caps won’t stop groundwater, which rises and falls with storms, from pulling PFAS trapped in soil under the caps down from below, where, once mixed with groundwater, the chemicals migrate offsite.

The contaminates that are already in the approximate three-foot zone where groundwater rises and falls gets washed out over a couple of years and the caps prevent additional contaminants from entering this zone, Massa said.

Airport says groundwater treatment won’t work there

Barnstable County, which is responsible for the PFAS plume at the fire academy, recently announced plans to expand the site’s existing groundwater pump and treat system, designed to remove PFAS from groundwater through carbon filters before the water reaches public drinking water wells, which are also outfitted with PFAS-removing carbon filters.

Servis said that’s a solution that won’t work for Cape Cod Gateway Airport’s PFAS plume.

In documents submitted under state cleanup regulations, airport staff also cited difficulty finding a site nearby to discharge treated groundwater that wouldn’t disrupt PFAS plumes in the area, and high, ongoing costs associated with the installation and operation of a groundwater treatment system.

Gottlieb said those explanations don’t cut it. The airport could buy the property it contaminated or seek an easement that would allow for the construction of a groundwater treatment system off airport land, he said.

“To my mind, that's an unconvincing and uncompelling answer, and it still leaves this nonsensical utilization of a public water supply as your primary extraction point, at which point you're treating the water,” Gottlieb said. “The fact that it’s migrated off site does not absolve them of the requirement to clean up under the Massachusetts hazardous waste statute.”

The airport is expanding. What will happen to PFAS dirt on site?

Airport staff also say digging up PFAS-contaminated dirt and shipping it to a hazardous waste storage or disposal facility – another cleanup method used at the fire academy – is not an option, despite the fact that excavators will likely start arriving on site in coming years for the airport’s expansion plan.

PFAS, which are referred to as “forever chemicals” because of their extremely strong chemical bonds, are hard to completely destroy. That makes disposal to hazardous and solid waste landfills a common option for getting rid of waste from PFAS cleanups, despite risks outlined in interim guidance on PFAS destruction and disposal issued by the Environmental Protection Agency in 2020.

In 2017, Barnstable County excavated 200 tons of PFAS-tainted soil from the fire academy, which was reportedly shipped to the now-capped Taunton Municipal Landfill. But as more became known about the hazards of PFAS, which contaminates landfill leachate that must then also be treated and disposed of, the number of landfills accepting PFAS-contaminated waste such as soil dropped.

Servis said finding a site willing to accept PFAS-contaminated dirt from the airport could be difficult, and disposal would likely be expensive.

But she said her objection to shipping tainted soil off site, where it could contaminate land elsewhere, is also a moral one.

“I don't think that's the right thing to do,” Servis said. “Let's handle it where we can handle it here until there is such a time that the technology is there, that shows that there's a different way to clean up PFAS soil. Eventually there will be, because the science will catch up.”

Chris Powicki, chair of the Cape & Islands chapter of the Sierra Club, said it's fair of Servis to question the morality of shipping the airport’s PFAS to a hazardous waste disposal site elsewhere, but leaving it in the ground will mean the burdens fall on Cape Codders.

Airport and DEP say oversight ensures construction won’t disturb PFAS contamination

Servis stressed that construction at the airport, much of which she said would not disturb the two acres of contaminated land on the 639-acre property, will involve careful coordination with DEP officials.

DEP Public Affairs Assistant Director Fabienne Alexis told the Times the state regulations require the airport’s licensed site professional to ensure expansion-related activities don’t worsen contamination or prevent future cleanup.

In February, the Massachusetts Environmental Policy Act Office determined that the airport's draft environmental impact report "adequately and properly complies" with state regulations, marking the clearance of an important hurdle on the way to expansion.

The next step in the process is the airport's submission of a final environmental impact report to the Massachusetts Environmental Policy Act Office. That report will likely incorporate responses to number of critiques and questions about the draft report from residents, government agencies, and groups including Association to Preserve Cape Cod and Sierra Club.

"Sometime in May, we'll have another public meeting, and then in the June-July timeframe, we'll have a final ready for public consumption," Servis said. The final report will likely be submitted to the state in August.

A February letter by Timothy Timmermann, director of the Environmental Protection Agency’s regional Office of Environmental Review, recommended the airport expand the groundwater section of the final environmental impact report to give more hydrogeologic information about the flow of potential contaminants, including groundwater flow continuing off-site.

EPA also requested that the final environmental impact report include a monitoring plan that describes how and when soil and groundwater will be tested for contaminants of concern, and how baseline soil and groundwater contaminant conditions would be established.

Powicki said that full cleanup of contamination should be a condition of expanding operations there.

“If they need to expand, why not take care of this problem now instead of burying it under more asphalt and expect downstream properties to deal with this issue?” Powicki said.

What does DEP say about the airport’s PFAS plans?

Like all contaminated sites in Massachusetts, Cape Cod Gateway Airport is required to find what DEP calls a “permanent solution” to its PFAS plume, Alexis, the DEP public affairs official, said, meaning the contamination poses no significant risk to human health, safety, the environment and public welfare.

The airport’s strategy of capping its hotspots and allowing the town’s drinking water filtration system to remove the underground PFAS coming from its property has not yet checked those boxes, according to DEP.

The last time PFAS-containing firefighting foam was used at the airport, which purchased test equipment that obviates the need to spray foam on the ground during testing a few years ago, was during an accident in July 2016, according to Servis.

While the airport no longer needs to spray foam during drills, if there were another emergency fire at the airport, AFFF would be used again, then cleaned up and disposed of, Servis said.

“At this point in time, we would use the firefighting foam we have on hand that is approved by the FAA but contains PFAS,” she said. “The FAA is in the process of approving other foams, but they are not yet PFAS-free.”

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This article originally appeared on Cape Cod Times: PFAS at Cape Cod Gateway Airport: Why it's there, how to get rid of it