PFAS Levels in Tap Water for 73 Million People in U.S. Exceed EPA Thresholds: NRDC Report

According to new map data from Natural Resources Defense Council (NRDC), more than 73 million people living in the U.S. are exposed to tap water with toxic levels of per- and poly-fluoroalkyl substances, or PFAS.

The data revealed that PFAS levels in tap water across the U.S. are higher than the safety thresholds set for these compounds by the U.S. Environmental Protection Agency (EPA) for 79% of congressional districts. Higher PFAS levels were detected in tap water in all but three states (Arkansas, Hawaii and North Dakota), NRDC reported. The maps also found higher PFAS levels in Washington, DC and all U.S. territories but American Samoa.

“Tens of millions of people across the country are currently at risk of drinking hazardous levels of toxic PFAS-contaminated water, and that risk may only increase for many years to come if the EPA successfully rolls back and delays PFAS standards,” Erik Olson, senior strategic director of health at NRDC, said in a statement. “No one voted to turn on their kitchen faucet and serve their family tap water laced with toxic chemicals.”

These findings are just the beginning, and contamination could be even more widespread, NRDC warned. NRDC created its maps using data from 2023 through the first quarter of 2025 from the ongoing Unregulated Contaminant Monitoring Rule (UCMR5) testing by the EPA, so tens of thousands of water systems in the U.S. have yet to be tested and reported. The UCMR5 has about 25% more testing to complete, meaning many more Americans could be impacted by PFAS-contaminated tap water.

Further, the data only considers regulated PFAS. When including unregulated PFAS in the testing, nearly half of everyone served by tested water systems had water supplies with some level of PFAS, NRDC reported.

The EPA currently has restrictions on six types of PFAS in tap water: PFOA, PFOS, PFHxS, GenX/HFPO-DA, PFNA and PFBS. However, the current administration has announced plans to repeal the health standards for PFHxS, GenX/HFPO-DA, PFNA and PFBS and to extend the compliance deadline for PFOA and PFOS to 2031.

As such, NRDC is warning that many more people are likely to be impacted by high PFAS levels in drinking water if repeals to health standards for these compounds are successful.

“The federal government knows toxic ‘forever chemicals’ are dangerous to our health and it’s well established that drinking water is a major route of exposure to PFAS for many people,” Anna Reade, director of PFAS advocacy at NRDC, said in a statement. “The PFAS crisis is immense, and we need more action, not less, to protect people from this extraordinary environmental and public health threat.”