At least five Missouri water districts reported levels of “forever chemicals” above federal limits, according to Environmental Protection Agency data. One Missouri city has contamination levels nearly three times the federal limit. 

The chemicals, scientifically known as per- and polyfluoroalkyl substances, or PFAS, are in hundreds of household items including cookware, carpeting, clothing, cosmetics, electronics and packaging. They also are a popular type of chemical firefighting foam heavily used on military bases. 

The chemicals have been tied to health issues such as thyroid disease, cancer risks, decreased fertility, reduced immune function and interference with hormonal function.

Because of their unique bonds, they take an incredible amount of time to break down. They even break down into other PFAS, like perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS), as they deteriorate, which leeches the forever chemicals into landfills, groundwater and wastewater systems across the country. 

The recently released 2024 EPA data shows PFAS detection across Missouri, with many water systems showing levels close to the federal limit, and a handful of others exceeding federal levels, a USA Today analysis found.

“Anywhere we’re testing for PFAS, we’re seeing prevalent levels of PFAS,” said Maxine Gill, a policy coordinator at Missouri Coalition for the Environment. “It doesn’t surprise me that we’re testing above the federal guidelines at this point in much of our water systems.” 

In 2024, several systems in the St. Louis region and some water districts in central Missouri had levels over the federal limit, the data found. 

Why PFAS chemicals are in Missouri water

The EPA released its first warning about PFAS in drinking water in 2009. For the first time in 2023, the EPA proposed enforceable limits on levels of certain chemicals in drinking water, and required all public water systems of a certain size to test their supply at least once from 2023 to 2025. 

Cities and water districts were required to test for 29 known forms of the forever chemicals, but experts say more than 16,000 different chemical compounds are circulating in our products, our landfills and our water supply systems. 

“The list of the uses of PFAS is jaw-dropping, and most of them are completely unessential,” said Erik Olson, the senior strategic director for environmental health at the Natural Resources Defense Council. 

Although some forms of the chemicals have federal limits on how much of them can be in the water supply, utilities have until 2031 to comply with those limits. 

Gill said expanded testing requirements are often a precursor to regulation. 

“It’s significant to have us even testing for these 29 different PFAS contaminants, but we need to be doing a lot more,” Gill said. “This is not the first time that we’ve heard about PFAS chemicals. This is just the first time that the federal government is mandating testing, and we’re seeing those results.” 

The Trump administration proposed rolling back limits on four of the six proposed chemicals and delaying compliance until 2031, though there are legal challenges to those changes. 

“PFAS regulations are now being challenged in court by the chemical manufacturers that make PFAS, and by some water utility trade associations,” Olson said.

Landfills are a large source of PFAS contamination in Missouri, Gill said. 

A study by the University of Illinois found that 80% of plastics are destined for landfills, where household items like cookware, food packages, clothing and other textiles leech microplastics and PFAS into the ground. The study found that PFAS concentrations in landfill byproducts were much larger than concentrations found in wastewater. 

After water goes through the wastewater treatment process, the highest levels of microplastics and PFAS are left behind in biosolids, otherwise known as sludge. 

The sludge is then often reapplied as fertilizer on farmland, but also carries the PFAS into the soil, groundwater and nearby waterways. 

In 2024, lobbyists for some of the sludge companies called themselves “passive receivers” of sludge containing PFAS. In a letter to Congress, they urged the federal government to not hold them accountable for the forever chemicals that were in the sludge they resold as fertilizer. 

“It is important to highlight that our members deliver essential public services that do not involve the manufacture or use of PFAS,” the groups wrote in the letter. “We are passive receivers of media containing PFAS that are ubiquitous in the water supply, wastewater treatment process, stormwater, biosolids management, and solid waste streams.” 

Overall, Olson said, the lobbying effort to roll back regulation is strong. 

“These guys are all over Washington, asking that they not be accountable for what they’ve done,” Olson said. “And in many cases, they’ve caused quite a bit of contamination.” 

In 2022, Missouri Confluence Waterkeeper participated in a nationwide effort to collect more PFAS data. The testing found that the highest total PFAS concentration in the Midwest region came from a downstream sample from Coldwater Creek, a tributary of the Missouri River in north St. Louis County. Coldwater Creek is primarily known for being heavily contaminated with radioactive waste from the Manhattan Project, a 1940s uranium refining effort to produce atomic bombs. 

High levels of PFAS have also been found in beers brewed in St. Louis County, a study found. The study found that areas with high concentrations of PFAS in their water also had higher concentrations of the chemicals in the beer produced there. 

“We and our partner organizations have been advocating for increased testing at this moment,” Gill said. “Of course, we want regulation, too. But in order to focus on regulatory efforts, we need to understand what the landscape of contamination is.” 

Cleanup isn’t easy, especially without the funds 

Unfortunately for consumers and the water systems that clean and provide their drinking water, PFAS chemicals are difficult and costly to clear out from the water supply. 

St. Peters, which had a measurement of 1.2 times over the federal limit, uses groundwater wells fin the Mississippi River floodplain and does not plan to conduct any investigation into the origin of the PFAS found in its water. 

“Our drinking water remains safe and meets all regulatory standards,” said Amy Haddock, the group manager of Water Environment Services for the city of St. Peters, in an email. “In accordance with the new federal standards, we are evaluating established PFAS treatment methods that could be integrated into our current water treatment process.” 

There are a few ways to treat water for PFAS, but they all require additional filtration methods that can be costly for cities or water districts. 

Certain types of carbon filters are the most popular to add to a water treatment system.  PFAS will stick to the carbon and separate from the water. But those filters need to be replaced regularly, and disposing of them means another layer of contamination to consider. Other methods are ion exchange, where PFAS binds to resin beads, or reverse osmosis treatment methods, which also produce a contaminated waste byproduct. 

Overall, the EPA estimates it would cost $1.5 billion annually to put drinking water rules in place, including testing, treatment options and disposal of byproducts. But water industry groups say it could cost anywhere from $37 billion to $48 billion over five years to install treatment, with  another up to $3.5 billion annually for operations. 

The EPA also found that it is easier for larger water systems to make treatment upgrades, as costs drop per customer served. 

In Canton, Missouri, city leaders found elevated levels of PFAS. After debating whether they should build an entirely new water treatment plant or purchase water from a nearby water district, city leaders opted to enter into an agreement with Clark County to purchase water. 

The Missouri Department of Natural Resources offers grants to Missouri cities to upgrade their water treatment systems, but they often require local matches. Haddock, the treatment manager in St. Peters, said the cost of upgrades is the biggest barrier. 

“I’m not sure what other cities’ challenges may be, but the cost of installing new treatment technologies is probably the biggest to overcome,” Haddock said. “PFAS treatment technologies exist, but they require significant upfront capital costs and upgrades to existing facilities to get them installed.” 

As testing expands across Missouri, experts say that the scope of contamination is likely greater than current data shows. 

But as more communities complete tests that show the forever chemicals in their water, Missouri officials and local water systems are still grappling with how, and when, to pay for treatment, and whether regulations will stay in place long enough to actually require it. 

“As we’re seeing more and more testing showing more and more PFAS contamination, and we’re understanding better the really detrimental health impacts of PFAS, we’re also rolling back our timeline on what the federal guidelines might look like,” Gill said.