Every single Missouri waterway sampled for PFAS between 2022 and 2024 came back contaminated, according to a new report, including popular fishing spots just north of Kansas City. Researchers found the so-called forever chemicals at all 20 testing locations examined across the state, a result that raises fresh questions about drinking water, fish and wildlife in waterways many Missourians use every day.
The findings come from researchers with the Environment Missouri Research & Policy Center, the MoPIRG Foundation and the Frontier Group, who reviewed testing data gathered statewide over that two-year window, according to the Columbia Missourian. The sites included waterways near both St. Louis and Kansas City, as reported by KSMU. Among the locations north of Kansas City were Little Tarkio Creek, Mill Creek and Todd Creek, all described in the report as popular fishing spots.
In all, the report identified 44 different types of PFAS turning up at one or more Missouri sites, per the same KSMU account. That local figure sits inside a much bigger national picture: nationwide, researchers detected PFAS at 83% of 1,602 testing locations spanning 40 states and the District of Columbia, according to KCUR.
Where the Chemicals Come From
PFAS, short for per- and polyfluoroalkyl substances, show up in everyday products including nonstick cookware, food packaging and waterproof clothing, the report notes. The chemicals can make their way into rivers, lakes and streams through industrial discharges, sewage treatment plants, firefighting foam and sewage sludge spread on farmland, and once they're in the environment, they break down very slowly.
To build the Missouri findings, researchers analyzed data from the U.S. Environmental Protection Agency's Water Quality Portal along with sampling conducted by local watershed groups, including Missouri Confluence Waterkeeper. The group says on its site that it is actively testing surface and drinking water for PFAS and other emerging contaminants across St. Louis City, St. Louis County and the rest of the state, and that it is taking part in a PFAS Stakeholder Workgroup organized by the Missouri Department of Natural Resources to help develop policies and tools for addressing contamination.
Researcher Says the Risk Extends Beyond Tap Water
John Rumpler, clean water director for the Environment Missouri Research & Policy Center and an author of the report, said PFAS testing and treatment efforts often focus narrowly on drinking water systems, even though river and stream contamination raises its own concerns. “Missouri's waterways should be clean and free of toxic chemicals,” Rumpler said, adding that people should not have to worry about tainted drinking water or contaminated fish.
Rumpler also pointed out that many rivers, lakes and streams double as sources of drinking water across the country, and he said cleaning up and filtering out PFAS after the fact is far more expensive than preventing the contamination in the first place. He cautioned that the true scope of the problem could be larger than the report shows, since many waterways haven't been tested at all and the analysis excludes some available testing data.
What the Report Does Not Establish
Despite the sweeping detection rate, the report's authors are careful to note that the findings do not establish the level of contamination or the health risk at any individual site, whether in Missouri or elsewhere in the country. Some PFAS compounds have been linked to decreased fertility, developmental delays in children, weakened immune responses and certain cancers, but the report stops short of tying those risks to specific Missouri waterways.
Surface-water monitoring itself varies widely from place to place, Rumpler told Truthout, which reported that researchers pulled together federal, state and nonprofit data collected between 2022 and 2024 for the broader national analysis. That inconsistency in how and where states test is part of why advocates argue the full extent of PFAS contamination is likely undercounted.
A Pattern Seen Across the Region
Missouri's results echo patterns found elsewhere in the country. Truthout reported that PFAS was detected at all 39 monitoring locations along the Mississippi River in Minnesota and Wisconsin, as well as at every monitoring location on and around Lake Ontario. Separately, The Beacon reported that a 2022 nationwide sampling effort found the Midwest region's highest total PFAS concentration in a downstream sample from Coldwater Creek in north St. Louis County.
On the regulatory side, the Beacon reported that the EPA required public water systems of a certain size to test their supplies for PFAS at least once between 2023 and 2025. The EPA says that, under the Safe Drinking Water Act, it has the authority to set enforceable National Primary Drinking Water Regulations for contaminants and to require monitoring of public water systems, according to the EPA. Separately, the Federal Register has recorded a proposed EPA drinking-water regulation and health-based goals covering six PFAS compounds, including PFOA.
For now, the report leaves Missouri with a stark headline number — contamination at every single site tested — without a clear picture of how dangerous that contamination is at any one creek, river or lake. Researchers and advocates like Rumpler say that gap is itself part of the problem, since limited testing makes it hard to know the full scale of what's flowing through the state's waterways.
