How America’s Wastewater Systems Became Conduits for “Forever Chemicals”

Under current federal regulations, industries are free to dump unlimited amounts of PFAS into public sewage systems that can’t remove them.

An aerial view of South Carolina’s Pocotaligo River. Photo by Brown Land & Plantation Advisors

On a hot, sunny day in August of 2024, Erin Donmoyer waded into the east branch of South Carolina’s Pocotaligo River and removed a “PFASsive passive sampling device” from its protective case. The gadgets are designed to measure PFAS concentrations in waterways. PFAS — short for per- and polyfluoroalkyl substances — are a class of more than 15,000 man-made chemicals used in everything from cookware to microchip manufacturing. Some of these “forever chemicals” are known to cause cancer in humans.

Donmoyer secured the sampling device to a stake in the riverbed and marked its GPS coordinates. She installed two of these devices in the Pocotaligo that day, placing one upstream of Sumter, South Carolina’s wastewater treatment plant, and another downstream of it. There the devices remained for 33 days, quietly accumulating whatever PFAS flowed past.

When she analyzed the results, Donmoyer was surprised. As a riverkeeper at Winyah Rivers Alliance — a Conway, South Carolina-based nonprofit working to protect, preserve, and revitalize the Winyah Bay watershed of the Carolinas — Donmoyer stewards two of the region’s major river systems: the Black River and the Sampit River. (The Pocotaligo is a tributary of the Black River.) Of these two river systems, Donmoyer expected the Sampit, lined with paper mills and chemical plants, to be the one with elevated PFAS levels. “But it really wasn’t,” Donmoyer says. “In terms of PFAS, the Black River is the major problem child out of my two.”

Erin Donmoyer samples water from the lower Sampit River, near Georgetown, SC. Photo by Michael Nagle

The Black River system is among the most PFAS-polluted waterways in the entire country, Donmoyer discovered. PFAS levels are particularly pronounced in the Pocotaligo, and much of this pollution seems to be coming from Sumter’s wastewater treatment plant. Upstream of the plant, Donmoyer’s sampling device logged PFAS concentrations of 110 parts per trillion. Downstream, levels spiked to 228 parts per trillion — a 107 percent increase. It was the highest contamination found at any of the 22 wastewater treatment plants tested in a nationwide study issued by the Waterkeeper Alliance in 2025, in which Donmoyer’s findings were published.

The Sumter plant serves roughly 51,000 people and receives wastewater from about two dozen industrial users, including metal coating facilities, plastics and tire manufacturers, textile operations, and chemical plants. All of these industries use PFAS in their manufacturing processes, and all of them generate large volumes of PFAS-contaminated wastewater. Sumter’s wastewater treatment plant has no PFAS removal technology. It has no limits on how much PFAS it can discharge into the Pocotaligo River, which flows into the Black River, which flows into the Great Pee Dee River, which flows into Winyah Bay and, ultimately, the Atlantic Ocean. From the wastewater it treats, the Sumter plant also produces over 1,000 tons of PFAS-laden sewage sludge each year. Much of this sludge is shipped to Florida, where it is spread and sprayed on farmland as fertilizer.

Sumter, South Carolina’s wastewater treatment plant. Photo by City of Sumter

Wastewater discharge pipe. Photo by U.S. Department of Agriculture

A tractor sprays sewage sludge on farmland. Photo by Paskvi via Pixabay

“This facility, which has the highest levels of PFAS pollution out of all the sites studied in the nation, is now sending their pollution to Florida as well,” Donmoyer says. “It ends up in livestock and crops — everything, forever.”

She’s not exaggerating. Thanks to their remarkably sturdy carbon-fluorine bonds, PFAS don’t break down or biodegrade — not on any human timescale, at least. Once released into the environment, they persist for incredibly long spans of time, contaminating air, water, and soil and bioaccumulating in the tissues of plants, animals, and people. Some of these chemicals, such as perfluorooctanoic acid (PFOA), are classified as “carcinogenic to humans” by the International Agency for Research on Cancer. Others, such as perfluorooctane sulfonic acid (PFOS), are classified as “possibly carcinogenic to humans.” PFAS have also been shown to impair immune system and thyroid function and have been linked to birth defects, liver disease, and kidney disease, among other maladies.

PFAS are, in short, just about the last thing you want in your food or water, and Sumter’s wastewater treatment plant is dumping untold numbers of them into the Pocotaligo River — and shipping truckloads of them to farms in Florida.

While the Pocotaligo’s PFAS load may be particularly high, this isn’t just a Sumter, South Carolina, problem. Across the country, industries discharge PFAS-contaminated wastewater into municipal wastewater systems that aren’t designed to remove these chemicals. Wastewater treatment plants, funded by taxpayers, inherit pollution they didn’t create and cannot eliminate, then pass it on to ecosystems and communities downstream — and to farmlands across the nation. Of the 22 wastewater treatment facilities examined in the Waterkeeper Alliance’s 2025 study, only one had any PFAS limits in its discharge permit (legal caps on the amount of pollutants a facility can release into waterways). None had PFAS removal technology. These facilities collectively serve tens of millions of Americans. All of this is perfectly legal under current federal regulations.

While the EPA has set drinking water limits for a handful of PFAS — including PFOA and PFOS — there are no federal regulations on how much of these forever chemicals industries can discharge into public wastewater systems, or how much of these forever chemicals public wastewater systems can discharge into rivers and streams. Let’s call it the “wastewater pretreatment gap.” This gap has major consequences for downstream communities.

In South Carolina, downstream from Sumter’s wastewater treatment plant, locals fish from the Black River and its tributaries for subsistence. “There are a lot of predominantly African American communities that go to the river to fish for their families, for food,” Donmoyer says. At Brewington Lake, a few miles upstream of where the Pocotaligo joins the Black River, state testing has revealed PFAS concentrations as high as 7,600 parts per trillion. (These state tests use traditional “grab samples” that measure total PFAS; Donmoyer’s PFASsive devices measure only dissolved PFAS, which better reflects what organisms are exposed to and typically yields lower concentrations.)

“We also have fish tissue data that the state collected from that same location,” Donmoyer says, “and they were like, I mean, astronomically high. One species was four times higher and one species was nine times higher than what North Carolina says is safe to eat in fish.” Donmoyer herself has autoimmune issues from high mercury levels as a child — the result of eating locally caught fish.

“It’s never safe to eat these fish,” Donmoyer says of fish caught at Brewington Lake. Photo by Sam Stukel

This is a problem elsewhere, too. The Vermont PFAS/Military Poisons Coalition — a Burlington-based nonprofit fighting to keep Vermonters safe from forever chemicals — has documented similar problems in the state’s Winooski River. Testing conducted by the group has revealed “huge amounts of PFAS” in the Winooski, downstream of the Montpelier wastewater treatment plant and a Vermont Air National Guard base that uses PFAS-containing firefighting foams. Test results published by the Vermont Air National Guard in 2020 showed PFAS concentrations exceeding 13,000 parts per trillion in a gully that drains from the base into the river, and concentrations of about 550 parts per trillion in the river itself.

“My community was a refugee resettlement community, so it was the most diverse community in the state of Vermont,” says Marguerite Adelman, who co-founded the organization in 2019. “Many resettled refugees fish in the Winooski River, downstream from fire training sites where they use these firefighting foams.”

Vermont PFAS/Military Poisons Coalition member Bob Ackland samples water from the Winooski River. Photo courtesy of Vermont PFAS/Military Poisons Coalition

Move Past Plastic — another grassroots group based in Carlisle, Pennsylvania — has discovered much the same thing in the state’s Conodoguinet Creek watershed. In collaboration with scientists from the American Geophysical Union’s Thriving Earth Exchange, the organization mapped PFAS pollution in the watershed in 2024. PFAS are widespread throughout the watershed’s 500 square miles, the mapping project found. The project also identified PFAS hotspots clustered around several legacy landfills, industrial sites, military bases, and wastewater treatment plants. State testing in public supply wells near one of the area’s old textile manufacturing sites logged PFAS concentrations as high as 8,500 parts per trillion, says Tamela Trussell, who founded Move Past Plastic in 2021.

“There are a million wells in Pennsylvania that people rely on for drinking water,” Trussell continues. “These wells aren’t regulated. The water isn’t regulated. They don’t have mandatory testing for any chemical.”

PFAS hotspots in Cumberland County, PA. Image by Move Past Plastic/AGU Thriving Earth Exchange

Cumberland County, where Trussell works, ranks near the 95th percentile for cancer risk and the 90th percentile for low life expectancy and heart disease. What role the region’s widespread PFAS pollution is playing in these health outcomes is unclear, but recent research shows that PFAS exposure is associated with all of them. A 2024 study in Environmental Health, which examined a large PFAS-contaminated area in northern Italy, linked PFAS exposure to elevated all-cause and cardiovascular mortality. And a study published last year in the Journal of Exposure Science & Environmental Epidemiology linked PFAS levels in drinking water to higher cancer incidence, estimating that PFAS in America’s drinking water supplies may contribute to as many as 6,800 new cancer cases each year.

All three of these groups — Winyah Rivers Alliance in South Carolina, the Vermont PFAS/Military Poisons Coalition, and Move Past Plastic in Pennsylvania — have documented PFAS pollution in their own backyards. All three groups are working to educate the public about the dangers of PFAS pollution. All three groups are pushing for better PFAS regulations, at both the state and federal levels. And all three groups agree on where to start: closing the wastewater pretreatment gap.

“If facilities absolutely have to use PFAS, then the impetus needs to be on them to remove it before it’s put in a public entity that’s funded by tax dollars,” Donmoyer says.

Trussell echoes this sentiment: “I think the step we need to take, in addition to regulating maximum contaminant levels in drinking water, is to regulate the discharge.”

Wastewater pretreatment requirements — requiring industries to remove PFAS from the wastewater they generate, before discharging it into public wastewater systems — would fundamentally shift the economic equation, these groups argue. Instead of externalizing the costs of PFAS use onto the public, companies that profit from these chemicals would bear the expense of managing them safely. “If you identify the problem, then you can put it back on the factories and say, ‘No, we don’t want that. We’re not going to accept this pollutant and make it a ratepayer issue,’” Donmoyer says.

Pretreatment requirements would fix that sewage sludge issue, too. If the wastewater that wastewater treatment plants receive doesn’t contain PFAS, neither will the biosolids these plants produce. “That’s another priority area,” Adelman says. “We want to get PFAS-containing biosolids and sludge banned from being spread on farmers’ fields.”

We have the technology to pull this off. Reverse osmosis and other advanced filtration systems have been shown to reduce PFAS levels in water by more than 99 percent. Some wastewater treatment facilities have already installed such systems. The question is who pays for them — and when the filtration happens.

A reverse osmosis water treatment plant in Bangladesh. Photo by CleanTech Engineering

Under the Biden administration, the EPA proposed federal limits that would have required industrial polluters to remove PFAS before discharging wastewater, but the Trump administration withdrew the rule in January 2025, leaving regulation largely to individual states.

“Many of our state agencies and the EPA already have grounds to take action on these polluters,” Donmoyer says. “We have the Clean Water Act, which says that you cannot just dump any sort of pollutant into the waters of the US without a permit saying you can do that, and most of these companies don’t have PFAS listed on their permits. There’s an existing legal avenue to stop PFAS pollution, but many places, including South Carolina agencies, are not utilizing the authority they have to stop it.”

Marguerite Adelman is slightly more cynical. “The truth is, you really can’t get rid of this stuff,” she says. “What you have are methods that just capture it. But you have to do something with that captured waste material. And so you have PFAS that just ends up back in a landfill. Until we ban PFAS, we are not going to see a change in our environment. We’re going to pay fortunes to get rid of this stuff.”

The wastewater pretreatment gap isn’t the only problem with PFAS regulation in the United States, but it may be the most glaring. Across the country, industries discharge unlimited amounts of forever chemicals into public systems that can’t filter them, leaving every community downstream — and every farm receiving biosolids — at risk. The technology to prevent this exists. The legal authority to prevent this exists. What’s missing is the political will to make polluters, rather than the public, pay the price for poisoning our water.

Note: A shorter version of this story originally appeared in The A2 Times, a publication of Anthropocene Alliance.