Every day, the Ohio River sends billions of gallons of water flowing past Louisville鈥檚 pumping station, where the Kentucky city鈥檚 utility sucks it up to turn it into tap water.
To ensure it tastes good and is safe to drink, a small team of scientists and technicians is constantly testing the water for pH, odors, heavy metals, and microbes.
But unlike many smaller municipal utilities in the U.S., regularly checks for PFAS 鈥� per- and polyfluoroalkyl substances.
That鈥檚 a class of chemicals used by manufacturers for decades to make things like nonstick pans, cosmetics, raincoats, food wrappers, and firefighting foam.
听听have linked PFAS to听听like cancer, reduced immune system functioning, high cholesterol, and developmental delays in children.
They鈥檙e also known as 鈥渇orever chemicals鈥� because their strong chemical structures make them degrade incredibly slowly in the environment.
Today, they litter听听and听听sources around the world and can be found听听of almost everyone in the U.S.
One type of PFAS that the Louisville water technicians are tracking is HFPO-DA, also known by a trade name,听.
Just over a year ago, workers noticed an unexpected increase in the level of GenX detected in a sample of the raw, untreated water drawn from the Ohio River for filtering and processing.
The GenX levels Louisville found in December 2024 were 15 times the reading from the previous month: 52 parts per trillion versus 3.4 ppt.
鈥淎 part per trillion is like one second in 32,800 years. Put your head around that, right?鈥� said听, the city utility鈥檚 director of water quality and research.
He offered another way to think of it: One part per trillion would be a single drop of water in 20 Olympic swimming pools.
Goodmann told 黑料吃瓜网 News and NPR he wasn鈥檛 worried about local customers鈥� safety, because the increased levels were still pretty low.
Risks posed by low PFAS concentrations are measured over a lifetime of exposure, he said. And recent data from Louisville shows the听听fell back within planned federal safety limits.
Plus, water is just one way people can be exposed to PFAS, Goodmann added. 鈥淏ecause you get a lot more of these pollutants from packaging, from prefixed food, cake mixes, weird things, you know, popcorn boxes,鈥� he said.
Louisville Water鈥檚 data showed that the elevated levels of GenX in the water sample drawn in December 2024 fell once the water underwent typical treatment and filtering.
Federal Regulation Fight
The federal government has long regulated the levels of听听in drinking water, such as arsenic, E. coli, and lead.
But the Environmental Protection Agency didn鈥檛 issue regulations regarding PFAS until 2024, during the final year of the Biden administration. The new limits applied to听听in drinking water. Starting in 2029, utilities that exceeded the limits would have been required to treat the water to reduce the contamination.
But after Donald Trump鈥檚 reelection, new EPA administrator听听听the agency will keep the rules for only two types of PFAS, called PFOA and PFOS, but drop the restrictions on the other four types, including GenX.
In addition, the EPA announced it will give water utilities two additional years, until 2031, to comply with the remaining rules, attributing the change in part to the financial burden on rural water plants.
Many utilities, large and small, may need to听.
A听听estimated about 45% of U.S. tap water contains at least one type of PFAS.
When it announced the final PFAS limits, the Biden administration anticipated that of the estimated 66,000 U.S. public drinking water systems affected by these regulations might have PFAS levels high enough to require them to take action to reduce the contamination.
Finding the Source
Goodmann鈥檚 team traced the increased levels of PFAS up the Ohio River, past Cincinnati, and through Appalachian forests, all the way to a West Virginia factory about 400 miles upstream.
There, the听听uses GenX听, a plastic critical to the semiconductors that power phones.
Its Washington Works facility near Parkersburg, West Virginia, has a听.
A lawyer,听, fought the plant鈥檚 previous owner,听, in court,听听the company knew that a type of PFAS it was using, PFOA, was toxic but didn鈥檛 disclose that information.
DuPont went on to听听听听that claimed it contaminated local environments with forever chemicals. The company has repeatedly denied wrongdoing.
Chemours was听听from DuPont in 2015.
The Louisville Water team鈥檚 calculations eventually showed that the December 2024 spike in GenX levels corresponded to publicly available data from Chemours about its chemical discharges into the Ohio River.
In Chemours鈥� responses to听听filed by a West Virginia environmental group, the company denied its discharges were connected to Louisville鈥檚 GenX spike. (Louisville is not a party in the lawsuit.)
The company also contended that sampling data showed levels of GenX in the river and in downstream utilities鈥� treated drinking water are 鈥渋ndisputably safe.鈥�
PFAS Removal Will Challenge Water Utilities
Under current federal environmental regulations, Chemours can release some chemicals into the Ohio River. But it has exceeded the legal limits repeatedly over several years, according to court filings and听.
That鈥檚 why the听听filed its lawsuit in 2024.
The EPA听听in 2023, when it said it found Chemours鈥� West Virginia factory had repeatedly exceeded permit limits for two types of forever chemicals, GenX and PFOA.
But the West Virginia Rivers Coalition said in a court filing that the EPA鈥檚 consent order for Chemours 鈥渋s not being diligently prosecuted.鈥�
Chemours declined to answer questions from 黑料吃瓜网 News and NPR, citing ongoing litigation, except to point out that Louisville鈥檚 鈥渇inished drinking water is safe for consumption,鈥� with PFAS levels below the EPA鈥檚 regulatory limits, as stated on and in the听听from Cincinnati, which also draws from the Ohio River.
As research into the health effects of PFAS exposure continues, environmental advocates say it鈥檚 imperative for companies to meet the limitations set by government permits.
鈥淓nvironmental regulatory permitting is a license to pollute,鈥� said听, the water policy director for the听.
鈥淵ou鈥檙e permitting someone to put something into the atmosphere, into water, into soil that would not be there otherwise. And so when we talk about the safe levels,鈥� he said, 鈥渟top using the word 鈥榮afe,鈥� right? This is the maximum allowable limit.鈥�
It is possible to remove PFAS from drinking water. For example, Louisville鈥檚 utility is spending about $23 million to redesign its powdered activated carbon system, which is one method used to take out PFAS.
But PFAS removal can get expensive, especially for small, rural towns, Hart said. Preventing contaminants such as PFAS from getting into a community鈥檚 drinking water supply is easier and less costly compared with removing it on the back end, he added.
In Chemours鈥� responses to the lawsuit, the company acknowledged that its violating its current permit but noted it鈥檚 working with government regulators on an eventual fix.
The federal judge in the case,听, decided that wasn鈥檛 fast enough.
In August, he听 overpolluting. The company quickly filed an appeal.
The West Virginia Rivers Coalition declined to speak with 黑料吃瓜网 News and NPR but did point to its听听on the judge鈥檚 ruling.
鈥淭his is a victory for public health and the Ohio River,鈥� Autumn Crowe, the organization鈥檚 deputy director, said in the statement. 鈥淭he Court recognized what communities have known for years: Chemours has been polluting our water and ignoring its legal obligations.鈥�
In a court filing for the case, Goodmann said that elevated levels of GenX could make it more challenging for water utilities such as Louisville鈥檚 to comply with federal rules for safe drinking water.
In regard to Chemours specifically, Goodmann told 黑料吃瓜网 News and NPR that when government regulators issue the company鈥檚 next听permit, he wants them to take into account the water treatment plants downstream.
鈥淪o what we do is manage risk, and we start that at the river,鈥� he said. 鈥淚t sounds weird, but source water protection 鈥� keeping the stuff out of the river 鈥� is a big deal.鈥�
This article is from a partnership that includes听,听, and听黑料吃瓜网 News.