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PFAS Testing of Drinking Water Systems

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PFAS detected

Chemical
Year Tested
Maximum Level (PPT)

PFAS detected

1
PFAS compounds are a class of non-stick, waterproof, stain-resistant compounds used in consumer products and industry. Best known are PFOA, formerly used to make DuPont’s Teflon, and PFOS, formerly in 3M’s Scotchgard.
2
Very low exposure to some PFAS chemicals has been linked to cancer, thyroid disease, weakened childhood immunity and many other health problems.
3
Tests of tap water, military bases and industrial sites have found PFAS contamination in more than 7,457 locations in 50 states, the District of Columbia and two territories. Drinking water for up to 200 million Americans may be contaminated with PFAS.
Learn more about PFAS
Source: EWG from https://www.ewg.org/tapwater/system.php?pws=
Levels listed are for the maximum of each PFAS detected at the time of the tests and do not reflect whether a water system is treating the water to reduce levels.

About the map

PFAS contamination in the U.S.
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 August 2024.There are 2,067 sites that reported PFAS via UCMR 5, as of August 2024.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 permissionrequests@ewg.org. EWG reviews requests on a case-by-case basis and reserves the right to deny permission for any reason, at its sole discretion.
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.
About the map