The Filthy Truth About Your Tap Water

The US is proposing bold action to clean thousands of “forever chemicals” out of drinking water. It’s long overdue.
jugs with water in them
Photograph: Michael Blann/Getty Images

Following years of concern, the US Environmental Protection Agency moved this week to clean up drinking water, announcing the nation’s first standards for six “forever chemicals” found in tap water. It’s a foreboding and informal name for human-made chemicals that coat nonstick pans, food packaging, and waterproof clothes before ending up in the water you drink. These chemicals, known as PFAS, or per- and polyfluoroalkyl substances, are pervasive and found in pretty much everyone—even newborn babies.

If the EPA rule is finalized, public water companies will need to monitor for the chemicals and keep two widely studied ones, PFOA and PFOS, below levels of 4 parts per trillion—around the lowest threshold measurable. The rule will also regulate combined amounts of four other types of PFAS chemicals. 

Experts say the proposal is monumental. It marks not just the first US national standard for regulating levels of these chemicals, but would also allow for widespread data collection to see which communities are most affected by contamination. Implementing these much needed fixes could take years and will be costly. Still, experts see this as a significant first step in pushing back against the PFAS problem, and one that could vastly improve water quality across the nation. 

“These are very strong, health protective, and a historic move to really limit exposure to contamination from these chemicals,” says David Andrews, a senior scientist at the Environmental Working Group, a nonprofit focused on health and environmental advocacy. “There are lots of opportunities to build off of this.” 

The PFAS regulation is not yet a reality; it's a proposed measure that could be finalized this year after a public comment period. If it is formally adopted, it will result in new expenses for many public water systems, requiring not only testing but filtering water when contaminants are detected. The utilities would have three years to comply with the rule, so some communities might not see results until 2026. 

The dangers of PFAS chemicals have become increasingly clear. High levels of exposure can cause fertility issues, developmental delays in children, and reduced immune responses, according to the EPA. They can also elevate the risk of several cancers, including prostate, kidney, and testicular cancer. 

The US National Academies of Sciences, Engineering, and Medicine released a report in 2022 saying health care providers should counsel and test patients who are more likely to have elevated PFAS exposure based on where they live or work. And EPA officials estimate that cleaning up the water will prevent thousands of deaths—and tens of thousands of cases of serious illness—in the US. 

Regulating the two commonly studied chemicals, as well as four additional ones, is “a really important first step,” says Katie Pelch, a scientist with the Natural Resources Defense Council (NRDC), a nonprofit environmental advocacy group. But there is more to learn about this vast group of chemicals and their prevalence. “This is still just a proposal to regulate six PFAS out of a class of thousands of chemicals,” she continues. The processes to remove PFAS could also tackle other chemicals found in drinking water, such as those from pharmaceuticals, flame retardants, and consumer products.

Still, EPA-mandated testing would provide a valuable close-up look at how prevalent these chemicals are. In the US, PFAS contaminants have been detected in more than 2,800 locations in all 50 states and two territories, according to data from the Environmental Working Group. A 2020 study found that as many as 200 million Americans may be exposed to PFAS in drinking water. 

But there are areas that have not done testing, obfuscating the full extent of the problem, says Laurel Schaider, a senior scientist at the Silent Spring Institute, a nonprofit that researches links between chemicals and women’s health. “That alone is going to be a game changer,” Schaider says.

PFAS are more prevalent in communities near manufacturing plants, airports, and wastewater treatment centers—all of which tend to be lower-income areas. If mandated testing begins, it could uncover vast disparities in PFAS concentrations. 

The EPA proposal is far more aggressive than a patchwork of existing regulations in US states like Massachusetts and Michigan, and experts say it may be the strongest to date around the world. It comes on the heels of action by the European Union, which updated its Drinking Water Directive in 2021 and set a combined PFAS limit of 500 nanograms per liter (equivalent to 500 parts per trillion) for drinking water. Canada recently proposed a new standard that would set the combined limit at 30 nanograms per liter (30 parts per trillion).

The World Health Organization has also released a new recommendation for limits of 100 parts per trillion for PFOA and PFOS in drinking water. The EPA’s proposed caps for those chemicals are much stricter, at just 4 parts per trillion. More than 100 scientists signed a letter criticizing the health agency for what they saw as a recommendation that ignored research and set limits too high. The discrepancy between WHO and EPA standards could lead some countries to set limits far above what scientists consider safe. 

Other water quality issues have persisted despite existing regulation. In the US, the Safe Drinking Water Act, passed in 1974 and since amended, regulates more than 90 contaminants found in tap water. But a 2017 report by the NRDC found that 80,000 violations of the act had been reported in 2015, affecting an estimated 77 million people and spanning 18,000 water systems. 

Regulators should also “think upstream,” when it comes to protecting people against forever chemicals, says Schaider. That means stopping their production and reducing their presence in the water system—not just filtering them out. The European Union is evaluating a proposal to ban the production and use of 10,000 PFAS chemicals. That’s the kind of action the US needs to take next, experts say. “Setting a drinking water standard is at the last step,” says Schaider, “after the contamination has happened.”