Millions of Americans are drinking water tainted with harmful chemicals, heavy metals, and radioactive substances, many at levels far above what scientists consider safe, according to the 2025 update to the Tap Water Database of the Environmental Working Group or EWG, a group that advocates for environmental health and human safety.
The EWG’s latest analysis includes water quality data collected between 2021 and 2023 from nearly 50,000 water systems. It identified 324 contaminants in drinking water across the country, with detectable levels in almost all community water systems.
“This is a wake-up call,” Tasha Stoiber, Ph.D., a senior scientist at the EWG, said in a statement. “Outdated federal regulations continue to leave millions of people at risk of exposure to harmful substances.”
Stoiber said the EWG’s Tap Water Database is the only resource providing consumers in every state access to accurate information about water contaminants, health risks, and steps to reduce exposure through filtration – information they need to take action.
By entering their ZIP code, users can find detailed information about the contaminants in their local water supply.
The levels of contamination in many locations fall below the U.S. Environmental Protection Agency’s outdated legal limits, but they often far exceed EWG’s health-based standards, the analysis of nationwide water utility tests found.
The update highlights contaminants in U.S. drinking water, including the toxic “forever chemicals” known as PFAS, that are in the drinking water of more than 143 million people. Tap water throughout the U.S. can also contain volatile organic compounds, nitrate and arsenic, other contaminants. These pollutants, often linked to cancer, developmental issues, and other health risks, are found in nearly all community water systems.
Harmful disinfection byproducts and radiological contaminants also persist in water supplies in many communities.
Hexavalent chromium, or chromium-6, is a carcinogen made famous by the Erin Brockovich case in Hinkley, California, and it’s in the drinking water of more than 250 million Americans.
There’s no federal limit for chromium-6, despite its widespread presence and link to cancer and organ damage, she said.
EPA efforts to safeguard drinking water continue to lag
Despite mounting scientific evidence and public concern about U.S. drinking water quality, federal action remains slow, said Melanie Benesh, vice president of government affairs at the EWG. In 2024, the Biden EPA introduced the first drinking water standards in more than 20 years, setting health-protective maximum contaminant limits for six PFAS.
“For too long, outdated federal standards have failed to reflect the latest science on drinking water, leaving millions exposed to harmful chemicals,” Benesh said. “While the new PFAS standards represent a historic step forward, they are only a fraction of what is needed to protect public health.”
The EPA standards are critical in reducing PFAS contamination in the nation’s water supply, she said. But these new protections could be at risk if the Trump administration tries to roll them back, along with weakening other steps the Biden EPA took to tackle PFAS pollution.
“Safe drinking water shouldn’t be a political debate – it’s a fundamental right,” she said. “A rollback of these hard-won protections would be a devastating setback. We must push for stronger, science-based regulations to ensure safe water for every American.”
