WASHINGTON – About 197 million people in the U.S. drink drinking water contaminated with the toxic “forever chemicals” known as PFAS, according to test data released by the Environmental Protection Agency and recent state test results.
That’s 23 million more Americans exposed to PFAS in drinking water than the EPA found in previous tests.
The number aligns with findings from a 2020 paper by Environmental Working Group scientists that estimated PFAS was in the water of 200 million Americans.
The new EPA findings mark the last installment of tests of the nation’s drinking water supply conducted as part of the Fifth Unregulated Contaminant Monitoring Rule, or UCMR 5, the regulation that required U.S. water utilities to test drinking water for 29 individual PFAS compounds.
The UCMR 5 data reveal 3,595 sites with detectable levels of PFAS, bringing the total number of known PFAS-contaminated sites to 13,459.
“The new data confirms what we feared: PFAS contamination of tap water is as widespread as our study estimated in 2020,” said David Andrews, Ph.D., EWG’s chief science officer.
Protections under threat
The EPA results come against a backdrop of increasing environmental deregulation. The agency is in the final stages of rolling back limits on four PFAS chemicals.
The agency is retaining first-time drinking water standards for the two most notorious PFAS – PFOA and PFOS. And the EPA set a health goal of zero for these two chemicals because it has identified no level in tap water that is without health risk.
“We already know PFAS exposure has been linked to a variety of health harms and can be harmful in extremely small amounts. Delaying, weakening or abandoning PFAS limits would be detrimental to public health.” Andrews added.
In 2024, the Biden EPA finalized first-time limits on six PFAS in drinking water. The limits, called maximum contaminant levels, or MCLs, set enforceable standards for the amount of contaminants allowed in drinking water.
In a reversal last year, Trump’s EPA announced plans to leave four PFAS unregulated – GenX, PFBS, PFNA and PFHxS.
The agency plans to retain the PFOA and PFOS standards at 4 parts per trillion. But it also wants to extend the compliance deadline for meeting those standards to 2031.
The EPA’s plan to reverse the four MCLs also likely contradicts an anti-backsliding provision in the Safe Drinking Water Act. That law requires any revision to a federal drinking water standard to “maintain, or provide for greater, protection of the health of persons.”
“This isn’t just a regulatory change, it’s a public health betrayal. These rollbacks will expose American families to chemicals linked to cancer and other serious health issues,” said Scott Faber, EWG’s vice president for government affairs.
“The EPA is abandoning science-based protections at the exact moment its own tests prove we need them most,” he added.
Widespread PFAS pollution
Even if the limits for PFOA and PFOS remain in force, scrapping the four other limits will make it harder to hold polluters responsible for endangering millions of Americans by releasing toxic forever chemicals into U.S. waterways.
The EPA’s toxicity assessments of GenX and PFHxS – replacement chemicals for PFOA and PFOS – found that exposure to even extremely small doses could pose similarly serious health risks. Finalizing the rollback means the agency wouldn’t enforce limits on GenX and PFHxS in tap water.
EWG estimates nearly 30,000 industrial polluters could be discharging PFAS into the environment, including into sources of drinking water. Restrictions on industrial discharges would lower the amount of PFAS ending up in drinking water sources.
Other organizations have found similarly concerning levels of PFAS contamination as EWG’s estimates. A recent report from Environment America found that PFAS was detected in 83% of rivers, lakes, streams and other surface waters between 2022 and 2024.
“It’s time to turn off the tap and address drinking water contamination at the source. For PFAS, that’s chemical plants, industrial sites and any manufacturers unnecessarily using these chemicals,” said Faber.
Health risks of PFAS exposure
PFAS are known as “forever chemicals” because once released into the environment, they do not break down, and they can build up in the body. The Centers for Disease Control and Prevention has detected PFAS in the blood of 99% of Americans, including newborn babies.
Very low doses of PFAS have been linked to suppression of the immune system. Studies show exposure to PFAS can also increase the risk of cancer, harm fetal development and reduce vaccine effectiveness.
“Consumers shouldn’t have to worry about the safety of the water that comes from their tap,” Andrews said. “With 197 million people exposed to PFAS in their drinking water, government regulators must hold polluters accountable and ensure utilities have the resources to remove these toxic forever chemicals.”
While the cost of removing PFAS from drinking water should not fall on consumers, numerous home filter options can help,” he added.
For people who know of or suspect the presence of PFAS in their tap water, a home filtration system is the most efficient way to reduce exposure. Reverse osmosis and activated carbon water filters can effectively remove these chemicals. But consumers should make sure to change their filters as recommended.
In 2023, EWG researchers tested the performance of 10 popular water filters to evaluate how well each reduced PFAS levels detected in home tap water.
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The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action. Visit www.ewg.org for more information.
