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Toxicity analysis of GenX-related pollutant coming soon from U.S. EPA

Military working on PFAS cleanup, seeking fluorine-free fire-fighting foam

by Cheryl Hogue
September 7, 2018

A photo of a woman holding a glass of water.
Credit: GSPhotography/Shutterstock
The U.S. Congress is probing into the contamination of drinking water with per- and polyfluoroalkyl substances.

The U.S. Environmental Protection Agency will soon release a toxicity assessment for hexafluoropropylene oxide dimer acid (HFPO-DA), a fluoroether that Chemours’s GenX surfactant hydrolyzes into. That’s according to an EPA official who spoke Sept. 6 at the first-ever congressional hearing on industrial per- and polyfluoroalkyl substances (PFASs). Some of these environmentally persistent chemicals are linked to illnesses, including cancer.

Drawing shows the structure of hexafluoropropylene oxide dimer acid.

HFPO-DA and other PFASs taint more than 100 km of the Cape Fear River downstream of a Chemours facility in Fayetteville, N.C.; groundwater around the plant; public drinking water supplies; and private wells. EPA also found the chemical in wells near a Chemours plant outside of Parkersburg, W.Va. GenX is the ammonium salt of HFPO-DA.

EPA will issue the toxicity assessment for HFPO-DA in the coming weeks, Peter C. Grevatt, director of the agency’s Office of Ground Water & Drinking Water, told the House of Representatives Energy & Commerce Subcommittee on Environment. The analysis will help inform cleanup of the compound from drinking water and perhaps, eventually, tainted sediments.

In addition, EPA will issue a national plan for managing PFAS pollution by the end of 2018, Grevatt added. The agency is still considering whether to set legally enforceable caps on specific PFAS substances in drinking water, he said. Those contaminants include two chemicals no longer made in the U.S. that are being detected in groundwater, rivers, and lakes across the nation: perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).

Some PFOS and PFOA pollution spread from military sites that released aqueous film-forming foam designed to fight fires. Some 400 active and former defense sites in the U.S. discharged or are suspected of releasing fire-fighting foams containing these substances, Maureen Sullivan, deputy assistant secretary of defense, environment, safety, and occupational health said at the hearing. Military firefighters were trained at most of these locales. The Pentagon plans to clean up these sites starting with the ones posing the greatest health risks to people, she said.

Meanwhile, the Department of Defense is working on cost-effective treatment options for groundwater tainted with PFOS, which is no longer used in fire-fighting foams, and PFOA, which is still found in trace amounts in some foams, Sullivan said. The military is also exploring whether it can switch to fire-fighting foams that don’t contain fluorinated surfactants. Thus far, no commercially available fluorine-free foams meet military performance specifications, she said.

The congressional subcommittee also heard from people dealing with PFAS pollution firsthand.

Emily Donovan, a grassroots activist from North Carolina whose family unknowingly drank PFAS-tainted water for years, asked lawmakers to commission a nationwide health study of those exposed to these substances. She urged them to require EPA to control environmental releases and cleanup of PFASs as a class. “We don’t have time to regulate these individually,” she said.

Donovan and others also suggested that EPA classify PFAS chemicals as hazardous substances under the nation’s Superfund law. This would allow EPA to use dollars from the federal fund for hazardous waste cleanup—the Superfund—to pay for remediation of PFAS contamination. It would also let the agency seek reimbursement for cleanup costs from those responsible for the pollution.


Although EPA, the Department of Defense, and the Department of Health & Human Services are working to address PFASs, other federal agencies need to be involved too, witnesses told the congressional panel. One is the Food & Drug Administration, said Erik D. Olsen of the Natural Resources Defense Council, an environmental group. FDA has jurisdiction over PFASs used to coat food containers, such as pizza boxes, to make them grease-resistant, he pointed out. Carol Isaacs, director of the Michigan PFAS Action Response Team, says the Department of Agriculture needs to help analyze whether PFAS compounds are in the U.S. food chain. Sewage sludge containing these substances is often used as fertilizer on farm fields, and home gardeners have watered vegetable plants with contaminated water.

Two Republicans, Reps. Fred Upton and Tim Walberg, and a Democrat, Rep. Deborah Dingell, all from Michigan, said they would introduce PFAS-related legislation the week of Sept. 10. Michigan is checking all its public water systems for PFAS pollution and, in some cases, finding it. In August, the state declared a state of emergency in one town after finding high levels of PFOA and PFOS in municipal water. The chemicals leached from a landfill containing paper mill waste.

Dingell said she suspects that more areas across the U.S. will face PFAS-related drinking water problems in the future as more water gets tested. “I fear this is only the beginning, and the crisis will continue.”


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