The foam, required by the Federal Aviation Administration, contains chemicals that are harmful and don't break down. Former firefighters say the foam was used liberally and rarely cleaned up.

Editor's note: This story is part of an ongoing collaboration between Environmental Health News and PublicSource on PFAS contamination in Pennsylvania and was funded in part through the Bridge Pittsburgh Media Partnership.

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When the Department of Defense first started looking into chemical contamination at its military bases next to Pittsburgh's airport, one of the first steps was to talk to seven of its officers, including the fire chief and environmental officer.

The military then used these accounts to determine what parts of its base may be contaminated with PFAS (perfluoroalkyl and polyfluoroalkyl substances) and what streams it may have escaped into.

The adjacent Pittsburgh International Airport has its own firefighting unit, so PublicSource spoke to five former firefighters who worked there between 1972 and 2010 about how the PFAS-containing aqueous film forming foam [AFFF] was typically used. Their accounts, along with the military review, airport records and scientists who study PFAS, indicate that contamination at the airport is likely.

Airport officials say they are doing everything the law requires but declined to say if they were taking additional steps to protect nearby residents. PublicSource asked the airport for records in December that describe any tests, environmental assessments or reports related to PFAS contamination. None were provided.

The firefighters who spoke to PublicSource remembered using the foam with little thought to cleaning it up: blanketing fuel spills with it, spewing it onto the ground during testing and practicing with it in the woods on oil fires, including in North Park.

Bob Scharding, a firefighter at the airport from 1987 to 2007, spoke of a lack of environmental concerns during the early years of his career. "In the old days, there was an anti-environment attitude," he said. "It's hard to believe that the [National] Guard base could compare to what the authority fire department did."

"Nobody ever talked about environmental contaminants," said Bryan Dopler, a firefighter who worked at the airport from 1986 to 2006.

The firefighting foam contains PFAS, a toxic class of chemicals associated with cancer, kidney disease and hormone disruptions. The airport used AFFF since the 1970s and, because PFAS doesn't break down, any of it that spilled is likely still in the ground. The airport switched to what it considers to be a safer foam sometime between 2000 and 2012, but did not say when it made the switch. Scientists say there isn't enough information to say for sure how safe the PFAS chemicals in the new AFFF are.

The way AFFF was handled at Pittsburgh's airport is similar to how it's handled at airports across the continent. A 2017 study by the National Science Foundation surveyed 167 airports in the United States and Canada between 2015 and 2016 and found that less than 7% of the airports treated AFFF during training like hazardous waste and less than 7% said they contained and cleaned up the AFFF after it was on the ground. And about four out of five airports said they left it on the ground to "dissipate" or "soak in" or "diluted" it.

Only 22% of airports said it was a best practice to use "containers or containment" to prevent spills of AFFF. Only 3% of airports that responded to the survey in 2015 and 2016 said they knew about PFAS contamination at their airports. Since that time, several airports have become aware of contamination and taken action and, according to Justin Barkowski, vice president of regulatory affairs at the American Association of Airport Executives, "most" airports have now begun testing.

Christopher Higgins, a scientist who studies PFAS contamination at the Colorado School of Mines, said Pittsburgh and many of these other airports almost certainly do have contamination.

"If they have their own fire training facility," he said, "it's almost a guarantee they have their own plume emanating from that facility."

The Pittsburgh International Airport's fire training facility was opened in 1999 and allowed for training without the use of aqueous film forming foam, which contains PFAS chemicals. But Federal Aviation Administration regulations still required its equipment to be tested at this site, where firefighters say foam spilled onto the ground. (Photo by Oliver Morrison/PublicSource)

When John Yeck first started his career as a firefighter at the Pittsburgh International Airport in 1972, firefighters were still using a protein foam to help prevent fires on runways.

"It smelled like when a baby shit its diapers," Yeck said. "They said it was made out of animal guts and stuff like that."

But there were problems with that foam. Yeck said the foam would corrode certain pipes, and it wouldn't work in certain weather.

"If it was rainy, it would thin it out too much. If it was hot and sunny, it would dry it out too much," he said.

During the early 1970s, Yeck said, the airport firefighters switched over to AFFF.

AFFF was more effective at smothering fires. It included a special chemical called perfluorooctane sulfonic acid [PFOS] that repelled both oil and water. PFOS is one of the two kinds of PFAS that has the most research showing its harm to humans and the Environmental Protection Agency has set a health advisory limit of 70 parts per trillion.

When firefighters put the new AFFF on an oil or gas fire, it would form a blanket over the fire, smothering the flames.

"[AFFF] not only extinguishes the fire, but it also creates a foam blanket that provides additional protection by preventing the fire from re-igniting and suppressing fuel vapors," wrote Robert Lindstrom and William Stewart in an international firefighting textbook.

The five former Pittsburgh airport firefighters said they were never told about the health consequences of AFFF and didn't see anyone make much effort to stop it from escaping into the environment. The foam was phased out by its manufacturer, 3M, starting in 2000.

Dopler noted the AFFF didn't appear innocuous to him. Dopler once walked through AFFF in a new pair of hiking boots. Six months later, when he went to find his hiking boots, he said, the rubber soles had come off. He attributed it to the foam.

"The stuff is corrosive," he said.

One of the advantages of AFFF over protein foam is that it mixes with water, so fire trucks had a lot more foam capacity. Every 100 gallons of foam requires only 3 gallons of AFFF and 97 gallons of water.

But sometimes the hoses put out too much water or too little AFFF or vice versa. The Federal Aviation Administration [FAA] requires airport firefighters to test their equipment to ensure the right ratio. The main turrets on the fire trucks spray water at a rate of 1,300 gallons per minute, Scharding said. That means in 20 seconds, a single hose would use 13 gallons of foam. Scharding estimated that the airport spilled thousands of gallons of AFFF just through this equipment testing alone over the decades.

"The FAA totally required it," Scharding said. "And, to the best of my knowledge, didn't really care how you went about doing it just as long as they got their numbers."

In 2019, the FAA approved a method of testing AFFF without discharging it onto the ground. Ann Richart, the former director of Martha's Vineyard airport, said, "All airports should make this transition immediately" during a March presentation for the Northeast chapter of the American Association of Airport Executives in Hershey, Pennsylvania. (Richart is now the aeronautics division director at the Nebraska Department of Transportation.)

Firefighters were required to practice once a year on a live fire as well. They said they went out to the forest and created a pond for the drills.

"It would be filled with water," Dopler said. "The oil would float on the top and we'd set it on fire and practice extinguishing it."

They didn't apply AFFF until the end of the drills because it would've been difficult to relight the fire after it was applied. They left the foam on the ground, they said.

The firefighters said this yearly fire training was moved to North Park for a few years around the late 1980s and early 1990s. Two of the firefighters remembered using foam at the North Park facility, which is run by Allegheny County Emergency Services.

"The Fire Training Academy's use of firefighting foam for training is very limited throughout the history of the current academy located at North Park," Matthew Brown, chief of Allegheny County Emergency Services, wrote in an email. "We only train in the proper use of firefighting foam 3-4 times annually. This training usually only involves the use of 5-15 gallons of AFFF in each instance."

There are no current plans to test for PFAS at North Park because of its "limited use," Brown said. The county is in the process of looking for a replacement foam for the training facility, he wrote, and that, "as more information regarding PFAS becomes available, we will continue to consider the need" for PFAS testing at North Park.

Yeck said he believes there should be paper records of the trainings on the airport property and at the North Park facility. "There was a report made out for everything we did," he said. "All of the training was documented."

But Scharding said he thinks some of the records may not be reliable. "We're talking going back 30 years, and everybody had a different way of doing things," he said. "They would write in their report, 'Used so much foam' or 'There was this much fuel on the ground' but it was all estimates, all guesstimates."

In 1999, the airport installed a more modern fire training facility, which allowed the firefighters to do their annual training on live fires without using AFFF.

One of the most frequent uses of AFFF, the firefighters said, was on fuel spills. When fuel was spilled near a plane during refueling, the fire department often sprayed a blanket of AFFF on top. That way the plane could take off without delay or fire. A study by Matthew Eichter, an Allegheny County firefighter, showed that there were between 30 and 37 fuel spills per year between 2006 and 2009at the Pittsburgh International Airport.

Greg Sample worked as an airport firefighter from 1984 to 2010. "Back then, you couldn't get the airlines to evacuate the planes when they had fuel spills, so they used [AFFF] to cover [it] up," he said.

The firefighters said the foam was rarely used on actual fires because there were so few plane crashes.

One exception was on Thanksgiving Day of 2001, when a Learjet crashed and caught fire just off of the runway. Firefighters arrived at the scene four minutes after the alarm and extinguished the fire in three minutes. But not before the plane was damaged extensively. They pulled two pilots out of the cockpit; they died from smoke inhalation. The accident report by the National Transportation Safety Board doesn't mention whether AFFF was used to extinguish the flames.

"That plane was probably foamed, but, other than that, there just weren't that many" times AFFF was used on real fires, Scharding said.

A 2017 study of PFAS contamination at airports, sponsored by the FAA, listed a number of potential contamination sites at airports. They include storage areas for AFFF, where the potential for leaks and spills existed; areas where AFFF was applied as part of an emergency response, foam testing or trainings; and historical disposal areas, including lagoons and retention ponds.

An October report showed PFAS chemical contamination at two military bases adjacent to Pittsburgh International Airport. (Photo by Ryan Loew/PublicSource)

The firefighters didn't know exactly how much AFFF had been purchased over the years but the airport's records show its receipts and purchase orders add up to 4,950 gallons between 2012 and 2018 at a cost of $110,314.

Bob Kerlik, the airport authority's director of media relations, emailed a statement in May that says the airport tests its foam two to three times per year and that "control systems and procedures are in place to minimize potential impacts." Kerlik didn't specify what those control systems or procedures are or whether the AFFF is still draining into the soil, groundwater and streams, as the firefighters said it had during their careers with the airport.

"We never put it inside a building," Scharding said. "It was always outside. So everything the airport bought for the last 40 years had to go into the ground and into the streams. I don't have the imagination for where else it could've gone."

Even when they tried to wash it into the ground or storm sewers, Scharding said, it was difficult because adding water to the AFFF concentrate would often just create more foam. "It was hell to get up," he said. "You could squirt it and squirt and squirt, like spilling detergent, except this is detergent on steroids."

James Nee, who worked as an airport firefighter from 1980 to 2003, said they didn't waste foam for unnecessary purposes but wanted to use all the foam they purchased because it was expensive. "It has a shelf life period," he said. "You have to use it within a certain time limit before it loses its ability to do what it's supposed to do."

The firefighters remember that commercial airlines spilled significant amounts of foam as well.

The airlines had emergency protection systems in their airplane hangars which, when activated, would discharge large amounts of foam. One airline's system was accidentally triggered in the late 1980s, Yeck said.

"And when we got over there, there was water and foam coming down," Yeck said. "You couldn't see 2 feet inside the hangar."

Scharding also recalled a local fire chief once calling the airport fire station to ask them to come apply foam because he was losing a restaurant to a fire on Allegheny River Boulevard. He couldn't recall what year it happened.

The airport authority has also used foam at the county airport in West Mifflin, which supports 60,000 takeoffs and landings per year.

Although the extent of PFAS contamination can depend on various factors, including the local hydrology and geology, the recent contamination in Burrillville, Rhode Island, demonstrates how little AFFF contamination is required for there to be serious consequences.

Matt DeStefano, the deputy chief of the Rhode Island Department of Environmental Management, said the fire department in Burrillville, a town of about 15,000 residents, spilled "maybe a gallon or two" of AFFF. And, as a result, more than 30 homes had to start receiving bottled water because the contamination of their well water was above the Environmental Protection Agency's health advisory. Now the town is building a $3 million water line to connect the residents to municipal water.

Oliver Morrison is PublicSource's environment and health reporter. He can be reached at oliver@publicsource.orgor on Twitter @ORMorrison.

This story was fact checked by Matt Maielli.

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