PFAS contamination in the U.S. (May 21, 2024)

Mapping the PFAS contamination crisis: New data show 6,189 sites in 50 states, the District of Columbia and four territories

Update: May 21, 2024: The Environmental Protection Agency has released the fourth round of public water system testing data for the “forever chemicals” known as PFAS, as required by its Fifth Unregulated Contaminant Monitoring Rule, or UCMR 5. The data reveal 1,593 sites have detectable levels of PFAS. The results highlight the sheer scale of the PFAS problem in the U.S. They build on EWG’s landmark PFAS contamination map. 


The number of U.S. communities confirmed to be contaminated with the highly toxic fluorinated compounds known as PFAS continues to grow at an alarming rate. As of May 2024 and the latest data shows 6,189 locations in 50 states, the District of Columbia and four territories are known to be contaminated.

The latest update of this interactive map shows PFAS pollution in public and private water systems. Details about our sources and methodology are here.

Information about sites newly added to the map comes from various PFAS detections reported to the EPA under UCMR 5, which requires monitoring of public water systems for 29 PFAS between 2023 and 2025. More data will be released on a rolling basis over the next two years.

Explore the map


The Environmental Protection Agency has known about the health hazards of PFAS for decades but has failed to limit PFAS discharges into the air and water or set cleanup standards.

The agency released a woefully inadequate PFAS action plan in 2019,which failed to include deadlines for action, and the EPA has made little progress.

The Department of Defense has been testing for PFAS at military installations but made little to no progress cleaning up any contaminated bases.

President Joe Biden has promised to tackle PFAS contamination by regulating the chemicals in drinking water, designating PFAS as hazardous substances under the federal Superfund law, stopping government purchasing of some products containing PFAS, and funding additional research into the chemicals.

In March 2021, the EPA announced it would regulate two PFAS – PFOA and PFOS, the two most notorious PFAS chemicals – in drinking water. But it could take years before these regulations are final.

The EPA has added 189 PFAS to the Toxics Release Inventory, or TRI, in response to a congressional mandate. A listing in the TRI requires facilities to report releases of those PFAS into the environment. But many manufacturers appear to be taking advantage of a loophole in the TRI that allows them to evade reporting requirements. The EPA has proposed but not finalized a rule to close this and other reporting loopholes. 

In October 2021, the EPA released a PFAS Strategic Roadmap, which includes accelerating efforts to set a national drinking water standard for PFOA and PFOS by 2023.

As part of that work, in March 2023 the agency proposed new drinking water contamination limits for six notorious PFAS: PFOA, PFOS, PFNA, PFHxS, PFBS and GenX. 

The limits, known as maximum contaminant levels, or MCLs, are the highest level of a contaminant allowed in drinking water. The MCLs announced are 4 parts per trillion, or ppt, for PFOA and 4 ppt for PFOS. For the other four PFAS, the agency proposes using a “hazard index,” a tool for addressing cumulative risks of mixtures of chemicals.

The agency also proposed designating PFOA and PFOS as hazardous substances under the Superfund law in September 2022. Some public water systems will have to continue monitoring for PFAS, as required by the UCMR 5. The EPA is expected to release more data from these systems in 2024 and 2025.

Congress has introduced dozens of bills to monitor the scope of PFAS contamination, ban non-essential uses of PFAS, address ongoing PFAS contamination, and clean up legacy PFAS pollution. 

A number of states are also taking steps to address PFAS pollution by banning some uses of the substances and setting cleanup standards.

The Environmental Working Group welcomes requests to reproduce EWG PFAS data for peer-reviewed articles in scientific journals. To request permission, please email a completed EWG Materials Request Form to [email protected]. EWG reviews requests on a case-by-case basis and reserves the right to deny permission for any reason, at its sole discretion.

About the Map

For all water systems with a detection of PFOS, PFOA or another PFAS, a maximum concentration for each PFAS and a maximum total PFAS concentration is displayed. The maximum levels listed are from a single point in time and do not reflect whether a water system has changed sources or is treating the water to reduce PFAS levels.

All locations represented on the map are approximate and intended to portray the general area of a contamination site or a community water system. Locations were mapped using the best data available from official records, including data provided by tests of public drinking water systems, the Unregulated Contaminant Monitoring Rule, the Safe Drinking Water Information System, the Department of Defense report “Addressing Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA),” among others.

Levels listed are for the range of the total of all PFAS detected at the time of the tests and do not reflect whether a water system is treating the water to reduce levels.

Data on contaminated water system, industrial and military sites was current as of May 2024.

Disclaimer: EWG has worked to ensure the accuracy of the information provided in this map. The map is dynamic. This contaminant site, results, suspected sources and other information in the database may change based on evolving science, new information or other factors. Please be advised that this information frequently relies on data obtained from many sources, and accordingly, EWG cannot guarantee the accuracy of the information provided or any analysis based thereon.

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