On the day Susan Gordon learned Venetucci Farm, in Colorado, was contaminated by toxins, the vegetables looked just as good as ever, the grass as green, and the cattle, hogs, chickens, and goats as healthy.
The beauty of the community farm she and her husband managed made the revelation all the more tragic. Chemicals known as per- and polyfluoroalkyl substances, invisible and insidious, had tainted the groundwater beneath her feet. PFAS had seeped into the soil from decades of training exercises that involved spraying firefighting foam at the nearby Peterson Air Force Base, in Colorado Springs. The hazard came to light when, in 2016, the US Environmental Protection Agency issued a health advisory recommending that drinking water have lower limits of two common types, PFOA and PFOS. Although the Air Force provided filters, the farm shut down in December 2017.
Once a symbol of American ingenuity, PFAS were originally conceived as wonder chemicals that could resist stains, repel water, extinguish horrific oil-based fires, and keep eggs from sticking to the pan. Today, we know them as a Frankenstein-like invention, zombie chemicals that will not die.
Chemists created thousands of such compounds by bonding carbon to fluorine in chemical chains, forging one of the strongest bonds ever discovered. Now they have been found across the planet—even in the blood of arctic foxes and polar bears. Public health studies found PFAS in the blood of about 95 percent of Americans. While the health impact of low levels of exposure is less clear, the chemicals are linked to liver, thyroid, and immune effects, cancer, and low birth weight. It will take billions of dollars—and yet more engineering prowess—to remove PFAS from drinking water and the environment. The task seems bleak, even as the US Department of Defense prepares to spend more than $2 billion on cleaning up PFAS on its bases. Firefighting training sites, airports, and industrial sites are also big contributors.
On Friday, the US House of Representatives passed the PFAS Action Act, which would require the EPA to set drinking water limits for two PFAS (PFOA and PFOS) and to designate PFAS chemicals as hazardous substances under the Superfund cleanup program. Its path forward is uncertain. Even if the Senate passes the measure, the Trump administration has called its provisions “problematic and unreasonable” and threatened a veto.
But here’s a shred of optimism: Some new technologies show promise in breaking those ultra-strong carbon-fluorine bonds, which means the compounds known as “forever” chemicals could be removed from at least some groundwater. “I have actually started to feel a little bit of hope,” says Chris Higgins, an environmental engineer at the Colorado School of Mines and a PFAS expert. “We’re getting some technologies that seem to be working.”
The most promising approach involves an electrical reaction that looks like lightning striking water. Contaminated water goes through a plasma reactor, where argon gas pushes the PFAS compounds to the surface. Electrodes above and below the surface generate plasma—a highly reactive gas made up of positive ions and free electrons—that interacts with the PFAS and breaks the carbon-fluorine bonds.
“Our goal is to completely destroy the compound and not just transfer it from one phase to another,” says Michelle Crimi, an environmental engineer at Clarkson University in Potsdam, New York, who works on emerging technology to remediate PFAS. The plasma reactor technique was developed by her colleagues Selma Mededovic, a chemical engineer, and Tom Holsen, an environmental engineer.
Crimi is also using ultrasound waves to create cavities—essentially holes—in the water. When they collapse, they instigate physical and chemical reactions that break apart the PFAS chains. Other researchers are working on electrochemical techniques and even soil bacteria that may metabolize PFAS.
Breaking down PFAS is an environmental feat. The typical remediation involves filtering water, which leaves PFAS residue that must be disposed of safely—forever. But even if groundwater can be pumped out, cleaned of PFAS, and reinjected into an aquifer, PFAS elsewhere will persist. For example, the techniques don’t clean the compounds from soil. “PFAS compounds are everywhere,” says Crimi. “It’s not practical to think that we can treat every drop of water, every grain of sand, and every single molecule of air.”
Despite having identified this far-reaching exposure, scientists still have a lot of questions about the scope of the PFAS problem. Higgins is leading a research team in Colorado, Michigan, and North Carolina that received a roughly $2 million EPA grant to better understand how PFAS moves through soil to groundwater, how it accumulates in foods, and what exposures pose the greatest risk to communities. Susan Gordon is on an advisory panel for the study.
Like the scientists, Gordon, the Colorado organic farmer, wants more information to come to light about the chemicals that upended her life. But even more, she wants people to understand the story of PFAS as a cautionary tale about man-made chemicals. Companies should not be allowed to produce new chemicals without first demonstrating that they’re safe, she says. “Once they’re out there and so pervasive, it’s really too late,” she says.
PFAS has been found in floor dust in children’s bedrooms; the chemicals have long been used to add stain resistance to carpeting and upholstery. In September, Home Depot announced the company would phase out carpets and rugs that contain PFAS. Several states have passed laws restricting the use of firefighting PFAS foams to actual emergencies, prohibiting its use in training exercises.
Meanwhile, more than 4,700 different PFAS chemicals have been created, and more are in development. The FluoroCouncil, an industry group, asserts that newer versions are safe—and essential to modern life, providing durable, low-friction materials for everything from airplanes to pacemakers. Yet Linda Birnbaum, who recently retired as director of the National Institute of Environmental Health Sciences, a federal agency, questions the creation of chemicals that do not degrade. “Even if some of them showed no toxicity whatsoever, I would still say, ‘Do we really want chemicals that will never go away?’” she says.
Gordon now owns and operates a small farm in Canon City, about 40 miles away from Venetucci Farm. Testing showed the vegetables at Venetucci didn’t end up absorbing PFAS, but she and her family drank the contaminated well water. Blood testing showed she has 100 times the level of PFAS found in the general US population. (Public health studies show the general population has an average level of one of the most common PFAS chemicals, PFOS, of about 6 micrograms per liter.) So far she has had no health effects, but she says, “Nobody knows what it will mean years from now.”
At some level, we all share that uncertainty. The Environmental Working Group, an advocacy organization, has identified 610 PFAS-contaminated locations in 43 states. Smaller exposures—in homes, offices, and potentially even in food—are ubiquitous. As long as the chemicals are “forever,” they remain a problem for us all.