Toxic PFAS Chemicals Found Above EPA Thresholds in Tap Water Serving Tens of Millions of People Across USA

WASHINGTON, D.C. – More than 73 million Americans are being exposed to dangerous levels of toxic “forever chemicals” in their tap water, according to new national maps NRDC (Natural Resources Defense Council) released today. Unsafe levels of these PFAS chemicals were detected in the water of 79 percent of congressional districts, the mapping tool based on data from the U.S. Environmental Protection Agency showed. PFAS chemicals endanger human health, including kidney and testicular cancer, liver damage, autoimmune diseases, and harm to the nervous and reproductive systems. 

Despite the scope and dangers of PFAS drinking water contamination, the EPA announced it will roll back and delay standards for six PFAS chemicals. These actions would be unlawful under the Safe Drinking Water Act’s “anti-backsliding” provision, which says the agency cannot legally weaken drinking water standards. The new maps are based on the standards that the EPA now says it will repeal. 

“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. No one voted to turn on their kitchen faucet and serve their family tap water laced with toxic chemicals,” said Erik D. Olson, senior strategic director of health with NRDC. 

Data highlights:

• PFAS have been found so far at levels above the EPA thresholds in all but three states (Arkansas, Hawai'i, and North Dakota). Also affected at PFAS levels above EPA thresholds are the District of Columbia and all U.S. territories except American Samoa. Further testing undoubtedly will uncover additional contamination.
• The vast majority (79 percent) of congressional districts are impacted by this PFAS-contaminated tap water above the EPA’s thresholds.
• Even though tens of thousands of water systems have not yet been tested or reported, the data collected under the EPA’s ongoing Fifth Unregulated Contaminant Monitoring Rule, so far already demonstrates that more than 73 million people are being served by water systems with water that were sampled and had at least one test above the EPA’s PFAS thresholds.
• When additional unregulated PFAS are considered, nearly half of the people across the nation whose water was tested were supplied by systems that detected some level of PFAS (136 million out of the 280 million whose water has been tested so far; many water systems still haven’t yet been tested or reported their PFAS results).

PFAS, known as forever chemicals because they don’t break down in nature, are used to produce items such as cookware, packaging, electronics, and cleaning products. PFAS can be harmful, even at extremely low doses, and are found in the bodies of virtually all people residing in America. The EPA has found that there is no safe level of exposure to some of the most widely detected PFAS chemicals.

The EPA restricted six PFAS chemicals in April 2024, the first time the agency issued a final rule on its own initiative for unregulated contaminants in tap water in 28 years. The chemical industry, which manufactures these forever chemicals that pollute the nation’s water, sued to block the rule; water utility trade associations, which are responsible for protecting their customers’ health from toxic chemicals in tap water, joined the chemical industry to challenge the PFAS rule. NRDC and its allies are intervenors in that litigation, seeking to protect the standards. 

Note about this data:

The PFAS data used to create NRDC’s maps were collected beginning in 2023 through the first quarter of 2025 under EPA’s ongoing Fifth Unregulated Contaminant Monitoring Rule  (UCMR5) testing. The UCMR5 data displayed in the map document that many water systems had at least one test result that was above EPA’s safety thresholds as established in its Maximum Contaminant Levels (MCLs) for the six PFAS. But that does not necessarily mean that these water systems will be in formal violation of these MCLs when (and if) they become effective. EPA’s rules allow water systems to use several slights of hand that allow them to stay in technical compliance with the MCL even if one or more samples exceed the standard. For example, EPA lets water systems average the results of multiple tests and use other tricks (such as rounding down detected PFAS levels of PFAS from, for example, 14 parts per trillion [ppt] down to 10 parts per trillion, and to still say they comply with a 10 ppt MCL). This approach may allow the water systems to stay in technical compliance with the rule even when some tests show elevated levels of PFAS exceeding EPA’s MCL threshold.    

NRDC (Natural Resources Defense Council) is an international nonprofit environmental organization with more than 3 million members and online activists. Established in 1970, NRDC uses science, policy, law and people power to confront the climate crisis, protect public health and safeguard nature. NRDC has offices in New York City, Washington, D.C., Los Angeles, San Francisco, Chicago, Beijing and Delhi (an office of NRDC India Pvt. Ltd).