Feature Story | 4-May-2023

Fighting back against ‘forever chemicals’ in firefighting foams

With more than $3 million from the U.S. Department of Defense, one University of Notre Dame researcher is on a mission to help eliminate PFAS on military bases

University of Notre Dame

“There is no contaminant in our nation’s history that has been regulated this fast,” said Kyle Doudrick, referring to the EPA’s new standards, proposed in March, for limiting levels of per- and polyfluoroalkyl substances (PFAS) in drinking water.

Doudrick, an associate professor in Notre Dame’s Department of Civil and Environmental Engineering and Earth Sciences, said the reason for the alarm over PFAS in water supplies is obvious: PFAS, often called “forever chemicals,” have been linked to an increased risk of cancer, liver damage, decreased fertility, increased risk of asthma and many other health problems.

PFAS can be dangerous even at very low levels, which is why the new proposed drinking water standards would limit some forms of PFAS to no more than four parts per trillion. “To imagine that amount,” Doudrick said, “you have to start by imagining one part per billion. That is about one drop of water in an Olympic-sized swimming pool. One part per trillion would be 1,000 times less — a fraction of a drop in a pool.”

In his research, Doudrick, who is also a faculty affiliate of the Notre Dame Environmental Change InitiativeNDnano ND Energy and the Pulte Institute for Global Development, uncovers new ways to identify, prevent and mitigate PFAS contamination. Doudrick said researchers have already made significant progress in identifying PFAS in cosmetics, containers, clothing and other consumer goods. And now, thanks to more than $3 million in grants from the U.S. Department of Defense, he is setting his sights on solving problems associated with another, less-understood source of PFAS contamination: military installations.

Much of the PFAS contamination on military bases comes from one specific product: aqueous film-forming foam (AFFF), also known as “firefighting foam.” Once lauded for its ability to suppress fires, AFFF has been phased out of production because it contains large amounts of PFAS. The challenge today — both at sites where fires were extinguished and where fire extinguishing training was conducted — is to remove the PFAS that linger within exposed materials without releasing the PFAS chemicals into the air, where they can be inhaled, or into the soil, where they can enter drinking water supplies.

One of Doudrick’s ongoing projects looks at one particular intervention: fighting the effects of firefighting foam with fire. Doudrick and his research group are exploring “thermal treatments” for pavements and soils that have been saturated with PFAS, including incineration. They are especially interested in discovering new additives and techniques that can lessen the environmental impact of incineration. Their findings could have important implications for hazardous waste operations around the country, many of which use incinerators.

Recently, the U.S. Department of Defense’s Strategic Environmental Research and Development Program announced funding for 74 new projects to begin this year, and two of Doudrick’s projects were among those selected.

Diogo Bolster, Notre Dame’s Frank M. Freimann Professor of Hydrology and Henry Massman Department Chair of the Department of Civil and Environmental Engineering and Earth Sciences, said, “It is rare for one university to have two projects from the same program funded — and even rarer for two projects from the same lab to receive funding. We are grateful to the Department of Defense for supporting Kyle Doudrick’s research, which has the potential to improve life for many of us.”

The Department of Defense’s support will allow Doudrick and his research group to branch out in their investigations in two new ways.

One new project will look at ways to handle pavements exposed to PFAS. Doudrick and his team will develop new ways to quantify the level of exposure, to understand how PFAS leach into and out of pavements, and what to do with pavements — including how to remove PFAS from the material and safe and effective ways to reuse the material afterwards.

Doudrick noted that last year the Department of Defense halted the incineration of materials containing PFAS until it could determine if incineration was safe for the environment. Doudrick’s research will go a long way toward answering that question.

A final project goes to the source of the contamination. Doudrick is developing a method to determine the total amount of PFAS present in new formulations of firefighting foam to ensure that these formulations are free of PFAS.

Doudrick said his work is just one part of a larger constellation of cutting-edge PFAS research at Notre Dame, which includes projects led by other environmental engineers as well as by aquatic biologists and physicists. Doudrick and his team also use a specialized suite of instruments for PFAS in collaboration with several of Notre Dame’s core research facilities, including the Mass Spectrometry and Proteomics Facility and the Center for Environmental Science and Technology.

“There are only a few universities in the world that have all the analytical capabilities for PFAS that we have here at Notre Dame,” Doudrick said. “It is important to keep pushing the boundaries of our understanding of PFAS and other emerging contaminants — not just because it makes for groundbreaking scholarship, but also because it is an issue connected to environmental justice. The water we drink and the air we breathe — these are shared resources, and what impacts them impacts all of us.”

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