DuPont introduced GenX in 2009 to replace PFOA, a compound it used to manufacture Teflon and coatings for stain-resistant carpeting, waterproof clothing, and many other consumer products. PFOA, also known as C8, was phased out after DuPont was hit with a class-action suit over health and environmental concerns. Yet GenX is associated with some of the same health problems as PFOA, including cancer and reproductive issues.
Levels of GenX in the drinking water of one North Carolina water utility, the Cape Fear Public Utility Authority, averaged 631 ppt (parts per trillion), according to a study published in Environmental Science and Technology Letters in 2016. Although researchers did not test the water of two other drinking water providers that also draw water from that area of the Cape Fear River, the entire watershed downstream of the Chemours discharge, which is a source of drinking water for some 250,000 people, is likely to be contaminated, according to Detlef Knappe, one of the authors of the study.
In North Carolina, GenX was present in water at even higher levels, with the most concentrated sample measuring 4,500 ppt. Although the EPA has not set legally binding regulations on every member of this class of chemicals, the agency set a drinking water standard for PFOA and the related chemical PFOS of 70 ppt. Several states have also set their own drinking levels for PFOA. Vermont has set the lowest so far at 20 ppt, and water experts in New Jersey have proposed an even lower level, 14 ppt.
Veterans of the battle over PFAS contamination find the company's claims about the environmental and economic benefits of GenX familiar. "This is the same kind of argument we have been hearing for several decades now," said Rob Bilott, an attorney who sued DuPont over another toxic PFAS chemical, PFOA, in 1999. The company had used PFOA for decades to make Teflon and other products and spent years defending it as an industrial necessity. DuPont only agreed to phase it out in 2006 after Bilott shared voluminous evidence with the EPA showing that exposure to the chemical led to cancers, liver damage, and immune effects, and only after the company had selected a substitute: GenX.
Even if the EPA denies Chemours' request for correction, drinkers of the contaminated water are already being forced to pick up hundreds of millions of dollars in costs to purify it. Brunswick is one of two counties in North Carolina that recently increased water rates to cover the cost of new systems installed to filter out PFAS. "Brunswick County is a poor, rural county, and people there are now paying to put in a reverse osmosis plant for their water treatment to PFAS specifically because Chemours will not," said Johnsie Lang, a scientist who has studied GenX. Lang, who lives in the county, saw her own monthly water bill rise from $130 to $180 in March.
Residents of the Wilmington area, whose drinking water records are aggregated by ZipCheckup, have already spent decades drinking water laced with the compound, which was released into the Cape Fear River as a byproduct of other processes before DuPont began producing it in 2009. In 2019, as news of the contamination spread, Chemours entered into a consent order with the North Carolina Department of Environmental Quality and the environmental group Cape Fear River Watch, in which it agreed to provide replacement drinking water to residents whose water has been contaminated with GenX.
The consent order requires the company to provide clean water to households whose water is contaminated above a certain level. "But they had no idea how big their plume was. At first, it looked like there would probably be like 100 or less houses," said Lang. But more than 6,000 now qualify. "And the number is still growing. I think they thought they were done, that they spent the money they wanted to spend."
Both Chemours and DuPont have also emphasized that GenX exits the human body more quickly than PFOA. But at a National Institute of Environmental Health Sciences conference, Linda Birnbaum, director of the institute at the time, downplayed the significance of that difference. "Every PFAS that has been studied is causing problems," said Birnbaum, whose agency funds scientific research into the chemicals. "Even if they have a shorter half-life, if it has a half-life of 30 days, it is going to build up in your body."
"It just blows my mind to see the number and diversity of different compounds that are out there," Andrew Lindstrom, a research scientist at EPA's National Exposure Research Laboratory and co-author of the North Carolina study, told the audience at the conference. "You have to ask yourself: how good is the drinking water treatment plant that is downstream? And very often the answer is not very good." Even the advanced water processing system used by the Cape Fear Public Utility Authority, which provided the water in the North Carolina study, was unable to keep the chemicals out. "We would expect that it would be very effective with a wide range of contaminants," said Knappe, "but these compounds zipped through the plant untouched."
In 2007, as it was phasing out the use of PFOA, DuPont applied to the West Virginia Department of Environmental Protection to update its emissions permit. A resulting 2011 consent order between the company and the state agency allowed the company to emit wastewater containing as much as 17,500 ppt of GenX into a receiving stream near the plant, an amount that is 250 times the EPA drinking water standard for PFOA and PFOS.
Chemours paid over $100 million for technology that reduces air emissions of GenX by 99.99 percent, as the consent order required. But the company has also been fined by the state Department of Environmental Quality for at least 16 violations of the consent order and related regulations, including exceeding the air emissions limit, disposing of waste improperly, and releasing more PFAS into water than allowed. And while the amount of GenX released from the North Carolina plant has clearly been reduced, shorter-chain PFAS have been found in water around the state, including on beaches and in home gutters, some as far as 80 miles from the plant.
The class action suit over PFOA yielded a historic $671 million settlement, but it took more than a decade to litigate. By spinning off Chemours, DuPont stanched its losses. And well before the case was decided, DuPont had already begun using and emitting its replacement, GenX. EPA monitoring conducted from 2013 to 2016, which tested for just six of the thousands of PFAS compounds, showed that 15 million Americans in 27 states have contaminated drinking water. The government is not currently monitoring drinking water for these chemicals.