NATIONWIDE — Want to know how much PFAS exists in your neighborhood water systems? The Environmental Working Group (EWG) has a resource for you.

An interactive map published by EWG shows PFAS test data for thousands of sites across the United States. It uses data gathered from official sources, including tests of public drinking water sources, to plot the locations and to list PFAS levels. 

PFAS, shorthand for “per and polyfluoroalkyl substances,” have seen widespread use since the 1940s because of their nonstick properties, including in cookware, clothing and firefighting foam. They also make up a widespread contaminant in the environment, one that poses significant health risks. An EPA fact sheet says they can increase the risks of developmental delays in children, reduce an immune system’s ability to fight infections and interfere with a body’s natural hormones, as well as have other negative impacts. 

The EWG map shows PFAS test results broken down by type of chemical. Locations on the map are color coded, with light blue dots marking locations where PFAS chemicals have been found above the EPA’s maximum contaminant levels. 

Sullivan County locations marked as exceeding that level include the Sullivan County International Airport, with PFOA hitting a high of 7.5 parts per trillion (ppt) during a testing period from 2021 to 2023; the Sullivan County Human Services Complex, with PFOS hitting a high of 9.0 ppt during a testing period from 2021 to 2023; and the Village of Monticello, with PFOS hitting a high of 4.2 ppt during a testing period from 2020 to 2023 and PFOA hitting a high of 4.9 ppt during a testing period from 2020 to 2025. 

The map does not reflect whether the water systems involved are actively working to treat for PFAS. EWG emphasizes that the information involved in the map is dynamic, and that “This contaminant site, results, suspected sources and other information in the database may change based on evolving science, new information or other factors.”

Under the Biden administration in 2024, the EPA had announced a final rulemaking for regulating PFAS. Under that rule, the MCL was set at 4 ppt for PFOA and PFOS. It was set at 10 ppt for PFHxS, PFNA and HFPO-DA, and any mixture of those three plus PFBS was given a hazard index of one. 

However, the EPA earlier this year, under the Trump administration, rolled back some of this proposed rulemaking. The changes would give water systems that request an extension until 2031 to implement changes, and would withdraw the regulations for the other four chemicals, claiming the Biden administration did not follow the proper process for that part of the rulemaking process. 

EWG and other environmental groups have decried the Trump administration move, with EWG president and co-founder Ken Cook saying, “The EPA was created to protect Americans from exactly this kind of chemical contamination. You cannot make America healthy again while allowing toxic PFAS to flow freely from our taps.”

To see the map, visit www.ewg.org/interactive-maps/pfas_contamination/map. 

Want to know more about the terms? Visit www.pfaswaterexperts.org.