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Portland firefighters spray foam at a training site in Northeast Portland as a demonstration in 2014. This foam is crucial for fighting intense fires like those from an airplane or oil train. But it also contains harmful chemicals that have seeped into groundwater. Alexi Horowitz / OPB

For years, firefighters and airfield crews trained to ward off flames by spraying thousands of gallons of foam fire suppressants, which eventually seeped into groundwater and could threaten to contaminate the Columbia River and a well field that supplies drinking water to the city of Portland.

Recent testing uncovered high levels of an unregulated class of harmful chemicals at two different sites in Northeast Portland, according to documents obtained by OPB under Oregon’s public records law.

One of those sites is the Portland Fire & Rescue Bureau training facility that sits a block from the Columbia Slough and within the boundaries of the Columbia South Shore Well Field, where the Portland Water Bureau draws from wells to supplement drinking water out of the Bull Run Watershed during summer months or emergencies.

The other location is the Portland Air National Guard Base, about a half mile west of the city's well field at its nearest point. In 2017, testing showed similar contamination at the Portland International Airport's fire training pits nearby, as first reported by the Portland Tribune.

These chemicals are known as per- and polyfluoroalkyl substances, or PFAS. They are used in everything from rain boots to nonstick cooking pans and have been linked to an increased risk of cancer, liver damage, asthma, thyroid disease and problems with fetal development.

And they have emerged as a nationwide threat to drinking water safety, one that federal regulators have drawn criticism over for not acting on them sooner.

“I know these compounds should not be there,” said Joyce Dinglasan-Panlilio, a University of Washington professor who has been studying PFAS since the late 1990s. “So I’d want it to not be there. So I would be really concerned if even a small amount of it is detected in water."

Documents obtained by OPB show that in Oregon, concerns have been expressed internally within environmental agencies about PFAS concentrations in Northeast Portland that far exceeded federal health advisory levels.

These regulators have questioned whether the contamination found in Portland has the potential to migrate offsite and contaminate the Columbia River, the Columbia Slough, private wells and — in the absolute worst-case scenario — a well field used to provide drinking water for more than 600,000 people in the Portland metro area.

Officials Say Water Is Safe

To date, city and state officials say they have not found any indications of an imminent threat to the city’s drinking water.

Groundwater sampled for PFAS in 2014 and 2015 had no detections of the chemicals. Neither did 2018 samples from the well nearest the contaminated fire station.

“Our drinking water is safe,” said Douglas Wise, groundwater protection program manager for the Portland Water Bureau.

Wise said his bureau had not detected contamination in areas of the well field where it has its primary wells for drinking water, but it is near areas the city might tap for drinking water in the future.

“It’s a pretty high priority right now because it’s new, and because there’s uncertainty,” Wise said. “Both because of the newness of the contaminants and the discovery, we want to keep our focus there.”

The highest concentrations detected at these sites were several times higher than the health advisory level for drinking water set by the U.S. Environmental Protection Agency and even higher still than the more protective limits recommended by the Center for Disease Control.

These chemicals are considered harmful at relatively minuscule levels — on the scale of drops in a swimming pool. The EPA’s health advisory level is just 70 parts per trillion. The CDC and other researchers made recommendations closer to single digits.

According to a site report released in October, preliminary testing at the Portland Fire & Rescue training facility found PFAS in all four sample wells. The highest concentration was 1,600 parts per trillion.

In January, the Air National Guard finished its site investigation. PFAS was present in surface water at 1,500 parts per trillion. The highest groundwater sample exceeded 40,000 parts per trillion.

"Oh wow. That is really high," Harvard researcher Xindi Hu said when told of the results. In 2016, Hu authored a study that found PFAS affects the drinking water of more than 6 million Americans.

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PFAS Contamination Sites In Northeast Portland

Three sites have been identified for high levels of perflourinated compounds used in firefighting foams. Those sites are shown below in red.

Elsewhere in the Northwest, PFAS chemicals have been found in Washington at Naval Air Base Whidbey Island, Fairchild Air Force Base in Spokane and in Oregon at Kingsley Field Air National Guard Base in Klamath Falls.

In some cases, contamination from the use of firefighting foam has been much higher than what’s been documented in Portland.

“If people are drinking water that’s connected to the watershed being polluted, especially since these compounds are not regulated, and people who are on private wells don’t have their water tested regularly, then there is potentially very high risk,” Hu said.

Chemicals Could Migrate

Officials with DEQ and the Portland Water Bureau said they are confident Portland’s drinking water will be unaffected.

Groundwater moves relatively slowly, they said. It takes more than a few hard spots of rain for contamination to travel long distances. Several layers of silt and clay separate the Water Bureau’s wells from the contaminated aquifer.

“We’re not trying to downplay the fact that there is contamination present,” Dan Hafley, project manager for the Department of Environmental Quality, said. “But it’s all about the potential for that to get to a point where it might actually have a harmful effect on humans or wildlife.”

However, Hafley said, the perfluorinated chemicals in question are known to be highly persistent in the environment, meaning they don’t break down easily. They are also highly mobile, meaning contamination spreads.

Environmental assessments done in the area found the groundwater flows primarily west and northwest, according to interviews and documents. DEQ and Water Bureau officials say that means contaminated groundwater should flow away from, not toward, the city’s wells, which are to the east. But the local flow direction can vary greatly depending on drainage ditches, river levels and other factors, documents show.

Pumping groundwater, as the city of Portland has done 17 times in the past 10 years, is also known to change natural groundwater flow. The Water Bureau says pumping in its deep aquifer wells is unlikely to affect the shallow groundwater where contamination was detected.

A northwest flow would carry contamination away from the well field but toward the river and slough, which has already been the target of cleanup efforts costing potentially up to $2 million. There has been a detection of PFAS where stormwater near the airport discharges into Columbia Slough, according to DEQ records.

There is also the issue of wells in the area beside the city’s. The National Guard alone, in an inventory of wells within a 1-mile radius of its base, identified more than 150 of them. The majority are monitoring wells not used for drinking water, but records show some are used for domestic drinking water consumption. Those wells have not yet been tested for PFAS as part of cleanup efforts.

Cleanups Underway

The Port of Portland, which operates the airport, along with the Air National Guard and Portland Fire & Rescue, have each entered into voluntary cleanup agreements with Oregon’s DEQ. Officials continue to monitor and investigate contamination at each site to determine the full nature and extent of the problem.

Col. Christopher Lantagne, commander of the Air National Guard Base near the Portland International Airport, said PFAS chemicals have been detected leaving the base at low levels through stormwater. The guard has expedited cleanup here, but Lantagne said a lack of guidance and established goals from the Environmental Protection Agency has complicated the process. Tony Schick / OPB

Portland Fire, which had been spraying up to 100 gallons per year of the foam since the mid-1990s, immediately suspended that training following preliminary test results in 2017, spokesman Rich Chatman said. The bureau also hired a company to dispose of the foam it had stored on site, which it finished last month. It has more site sampling planned this month.

Col. Christopher Lantagne, commander at the Portland Air National Guard Base, said the base has switched to foams containing lower concentrations of PFAS. It also plugged trench drains at its aircraft hangers to prevent chemicals from entering the city’s wastewater treatment system.

Lantagne said there is evidence of PFAS leaving the base in stormwater, but he doesn’t yet know where it goes downstream. Because of that, and because of the base’s proximity to a large population and the city’s well field, the base in Portland is one of six National Guard bases across the country that the U.S. Department of Defense targeted for an expanded investigation.

Editor's note: This post has been updated for clarity based on additional information provided by the Portland Water Bureau.