Forever Chemicals in America's Waterways Raise Alarming Concerns
Guest Contributor
Across the United States, rivers, lakes and streams are places people go to drink, fish, paddle and relax. A growing body of evidence shows that these same waters are increasingly contaminated with per- and polyfluoroalkyl substances, or PFAS, often called “forever chemicals.” An extensive analysis of monitoring data between 2022 and 2024 points to a troubling reality about PFAS in surface waters and underscores why so many advocates are now calling for strong action, from phasing out PFAS in products to telling cookware companies “no PFAS in our pans.”
PFAS are a large class of synthetic chemicals valued in industry and consumer goods for their resistance to heat, water and stains. The same qualities that make them useful also make them persistent. They break down very slowly, if at all, and can accumulate over time in the environment and in people. Long term exposure to certain PFAS has been associated in scientific studies with elevated risks of some cancers, immune system suppression, reproductive and developmental issues, and other adverse health effects. Once these compounds are released into rivers, lakes and streams, they can remain dissolved in the water and build up in sediments and aquatic organisms.
The analysis summarized in the report draws primarily on the U.S. Environmental Protection Agency’s Water Quality Portal, a national clearinghouse that compiles federal, state, tribal and local water quality data. Additional surface water PFAS monitoring results were obtained from Waterkeeper Alliance and its network of local Waterkeeper organizations, as well as state agencies in Maine and Massachusetts. The focus is specifically on surface waters such as rivers, lakes, reservoirs and streams. Samples identified as drinking water, groundwater or wastewater were excluded in order to paint a clearer picture of PFAS in natural water bodies.
From 2022 through 2024, PFAS were detected at least once at 1,329 of 1,602 monitored locations across the country. That is roughly 83 percent of the sampled sites. Monitoring covered as many as 174 different PFAS compounds, of which 114 were detected at least once. Individual monitoring locations did not test for all 174, so the picture of contamination at any given site is inherently partial. PFAS compounds also differ in toxicity and persistence, and some have been far more thoroughly studied than others. A lack of toxicity data is not proof that a particular PFAS is safe. Nevertheless, the widespread detection of so many different PFAS compounds points to a broad pattern of contamination.
The monitoring data are not comprehensive. Many waterways are not sampled for PFAS at all, and not all state and local test results are reported through the Water Quality Portal. Several states including Colorado, Michigan, New York, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, Washington and Wisconsin publish additional PFAS surface water data through their own platforms. Some of these data are included in the analysis, while others fall outside it. As a result, the authors conclude that the documented contamination is likely only a fraction of what exists nationwide.
PFAS reach rivers, lakes and streams through an array of pollution pathways. Industrial facilities may discharge PFAS directly into waterways or send contaminated wastewater to sewage treatment plants. Municipal treatment plants are typically not designed to remove PFAS and can pass them on in their effluent. PFAS also appear in landfill leachate, which is sometimes sent to the same treatment plants. Sewage biosolids that contain PFAS are often sold as fertilizer and spread on farmland. From there, PFAS can run off into nearby waters. In addition, years of using PFAS-containing firefighting foam at military bases, airports and training facilities have contaminated surrounding surface waters at many locations.
For chemicals that persist in the environment and move through so many channels, the report argues that there is no fully safe way to “manage” widespread use. Instead, the data point to the need to stop PFAS pollution at its source. I found this detail striking, because it shifts the focus away from trying to clean up water after contamination occurs and toward preventing these compounds from entering the environment in the first place.
Case studies from specific waterways illustrate how PFAS contamination shows up on the map. Along the Mississippi River in Minnesota and Wisconsin, PFAS were detected at all 39 monitoring locations analyzed. Thirteen different PFAS compounds appeared in samples there, with the highest measured concentration reaching 23.3 nanograms per liter (ng/L) for PFBA near Hastings, Minnesota. Oral exposure to PFBA is considered likely to cause thyroid, liver and developmental effects in humans, which adds public health weight to those measurements. The Mississippi sampling sites in this region are near a mix of potential PFAS sources, including airports, military facilities, wastewater treatment plants and oil refineries.
Another example is Lake Ontario, where PFAS were detected at all monitored locations during the study period. Eight different PFAS compounds showed up at least once, and PFBA again reached the highest measured concentration there at 11 ng/L. In Washington state, Tiger Lake, a freshwater lake used for fishing, kayaking and paddling, also showed contamination at every monitored site. Across six locations around Tiger Lake, monitoring found 36 different PFAS compounds, with a highest quantified concentration of 19 ng/L for PFBS. These findings matter not just for swimmers and paddlers who come into direct contact with the water, but also for people who eat fish that may accumulate PFAS over time.
Separate research, referenced in the report, has documented PFAS accumulation in freshwater fish and raised concerns that fish consumption is a potentially significant source of PFAS in people. This concern ties back to the broader observation that PFAS, once released, do not simply vanish. They can move through food webs and reappear on dinner plates, complicating efforts to protect public health.
Some locations in the dataset stand out for extremely high PFAS concentrations, most of them associated with firefighting foam incidents or facilities. The highest reported concentration was at a stormwater retention pond inlet in Brunswick, Maine. In August 2024, approximately 1,450 gallons of aqueous film-forming foam, mixed with about 50,000 gallons of water, were accidentally released from Brunswick Executive Airport into nearby stormwater ponds. Testing by the Maine Department of Environmental Protection found PFOS at 1,040,000 ng/L at one inlet, which is several orders of magnitude higher than other sites in the dataset.
Other places with especially elevated PFAS readings include Lake Holloman in New Mexico near Holloman Air Force Base, where PFHxA concentrations reached roughly 30,000 ng/L; Sargent Creek in Minnesota near a fire training facility; the Animas River in Colorado; waterways near Milwaukee Mitchell International Airport in Wisconsin; and locations near Fernando Luis Ribas Dominicci Airport in Puerto Rico. The past use of PFAS-containing firefighting foam at these airports and military facilities has been identified as a key source of contamination.
The report devotes considerable attention to how monitoring data were handled. Records from different agencies and organizations were standardized so they could be compared meaningfully. PFAS compound names and reporting units were harmonized, with concentrations converted into common units such as nanograms per liter. Sampling locations were mapped using geographic coordinates and state boundaries. Data that did not represent actual environmental samples, such as laboratory or field blanks, were excluded. Records with clear quality-control problems, such as contamination affecting results, were also removed.
Each test result was then classified as either a detection or a non-detection. A result counted as detected when there was a numerical value indicating PFAS was present or when laboratory notes showed the compound was identified, even if it was below the level that could be accurately quantified. If a record indicated that a PFAS compound was below the laboratory detection limit, or there was insufficient evidence that PFAS was present, it was treated as a non-detection. The authors note that because PFAS are harmful at very low levels and all analytical methods have limits of detection, a non-detection does not guarantee that PFAS are completely absent from a sample.
Using this standardized dataset, the analysis then summarized monitoring results at the level of each location. For any given site, the authors calculated how many times PFAS were tested, how many different compounds were analyzed, how many compounds were detected at least once, and how many separate sampling events took place. These metrics help describe not just whether PFAS showed up at a location, but also how consistently they were present and how broad the contamination might be across different PFAS compounds.
Despite the sobering scale of contamination, the report points to reasons for cautious optimism. After certain manufacturers began phasing out some of the most common PFAS compounds, researchers found declining levels of those specific chemicals in Great Lakes fish. This suggests that when production and use of particular PFAS decrease, environmental and biological levels can respond over time. It also reinforces the report’s central conclusion. Monitoring is crucial to understanding PFAS in America’s lakes and streams, but monitoring alone cannot solve the problem. Protecting rivers, lakes and streams from forever chemicals ultimately requires stopping PFAS pollution where it begins, in manufacturing processes and in the many products that currently rely on these persistent compounds.