The U.S. Environmental Protection Agency's final rule establishing maximum contaminant levels for six per- and polyfluoroalkyl substances, or PFAS, in public drinking water took effect in June 2024, marking the first time the federal government set enforceable limits for the class of synthetic chemicals sometimes called "forever chemicals." Water systems serving 66,000 utilities and approximately 100 million people now have until 2027 to test, report exceedances, and implement treatment where needed. Two years into the compliance window, testing data compiled by the Environmental Working Group shows exceedances in water systems across at least 41 states.
What the Rule Covers | Six Compounds, New Thresholds
The EPA set maximum contaminant levels for PFOA and PFOS, the two most studied PFAS compounds, at 4 parts per trillion, down from previous health advisory levels of 70 parts per trillion established in 2016. The rule also covers PFNA, PFHxS, HFPO-DA, commonly known as GenX, and a mixture provision covering combinations of PFNA, PFHxS, PFOA, and PFOS at a hazard index of 1.0.
PFAS are a family of approximately 12,000 synthetic chemicals used since the 1940s in nonstick cookware, firefighting foam, food packaging, waterproof clothing, and industrial applications. They do not break down in the environment or the human body, and accumulate in the blood, liver, and kidneys. Studies have linked chronic exposure to increased risks of kidney and testicular cancer, thyroid disease, immune system disruption, elevated cholesterol, and adverse pregnancy outcomes.
Who Is at Highest Risk | Geography and Demographics
Testing conducted under the EPA's Fifth Unregulated Contaminant Monitoring Rule between 2023 and 2025 identified the highest PFAS concentrations near current or former military bases where aqueous film-forming foam was used in fire suppression training, industrial manufacturing sites, and communities adjacent to airports. States with the largest number of affected systems include Michigan, Pennsylvania, New Jersey, Ohio, New York, and California. Smaller water systems serving rural and low-income communities face a disproportionate compliance burden because they lack the capital and technical capacity to install granular activated carbon or reverse osmosis treatment, the two technologies the EPA considers best available for PFAS removal.
A 2025 analysis by the Environmental Defense Fund found that water utilities serving majority-nonwhite communities were 1.6 times more likely to have detected PFAS above the new MCL thresholds than those serving predominantly white communities, a disparity researchers attribute to historical siting patterns of industrial facilities and military installations. HoneyNewspaper community reporting has covered environmental justice dimensions of water contamination, including Cancer Alley and lead exposure disparities.
Remediation Costs and Infrastructure Gaps
The EPA estimated at the rule's publication that compliance costs would reach $1.5 billion annually across all affected systems. Water utility associations, including the American Water Works Association, have argued the actual figure could be two to three times higher once installation, ongoing maintenance, and waste disposal costs for spent filter media are included. Spent granular activated carbon and reverse osmosis concentrate must be disposed of as hazardous waste in many jurisdictions, adding ongoing operational costs that do not appear in the EPA's original estimates.
Congress has appropriated approximately $10 billion through the Bipartisan Infrastructure Law for PFAS remediation at water utilities, but advocates say funding is insufficient and distribution has been slow. As of May 2026, the EPA reported that less than $2 billion of the available funds had been drawn down by utilities, due to administrative bottlenecks and the technical complexity of applying for infrastructure grants.
What Residents Can Do While Systems Upgrade
Residents served by water systems that have reported PFAS exceedances have limited options while treatment systems are being installed. The EPA and CDC recommend that pregnant women, infants, and immunocompromised individuals in affected areas use certified point-of-use reverse osmosis filters, which effectively remove PFAS, or bottled water. Standard pitcher filters such as Brita do not remove PFAS to levels below the new thresholds.
The HoneyNewspaper public health desk covers water contamination, air quality, and the environmental factors that shape community health outcomes. Related coverage: pollutants in the living world | corporate accountability and chemical regulation | PFAS in food packaging. The full EPA PFAS rule is available at the EPA Safe Drinking Water Act portal.