The Biden-Harris Administration has issued the first-ever national, legally enforceable drinking water standard to protect communities from exposure to harmful per-and polyfluoroalkyl substances (PFAS), also known as “forever chemicals.” Exposure to PFAS has been linked to deadly cancers, impacts to the liver and heart, and immune and developmental damage to infants and children. This final rule represents the most significant step to protect public health under EPA’s PFAS Strategic Roadmap. The final rule will reduce PFAS exposure for approximately 100 million people, prevent thousands of deaths, and reduce tens of thousands of serious illnesses.

“Drinking water contaminated with PFAS has plagued communities across this country for too long,” said EPA Administrator Michael S. Regan. “That is why President Biden has made tackling PFAS a top priority, investing historic resources to address these harmful chemicals and protect communities nationwide. Our PFAS Strategic Roadmap marshals the full breadth of the EPA’s authority and resources to protect people from these harmful forever chemicals.”

The EPA is taking a signature step to protect public health by establishing legally enforceable levels for several PFAS known to occur individually and as mixtures in drinking water. This rule sets limits for five individual PFAS: PFOA, PFOS, PFNA, PFHxS, and HFPO-DA (also known as “GenX Chemicals”). The rule also sets a limit for mixtures of any two or more of four PFAS: PFNA, PFHxS, PFBS, and “GenX chemicals.”

The EPA estimates that between about 6 percent and 10 percent of the 66,000 public drinking water systems subject to this rule may have to take action to reduce PFAS to meet these new standards. All public water systems have three years to complete their initial monitoring for these chemicals. They must inform the public of the level of PFAS measured in their drinking water. Where PFAS is found at levels that exceed these standards, systems must implement solutions to reduce PFAS in their drinking water within five years.

The new limits in this rule are achievable using a range of available technologies and approaches including granular activated carbon, reverse osmosis, and ion exchange systems. Drinking water systems will have flexibility to determine the best solution for their community.

More details about the final PFAS drinking water standards follow:

• For PFOA and PFOS, the EPA is setting a Maximum Contaminant Level Goal, a non-enforceable health-based goal, at zero. This reflects the latest science showing that there is no level of exposure to these contaminants without risk of health impacts, including certain cancers.
• The EPA is setting enforceable Maximum Contaminant Levels at 4.0 parts per trillion for PFOA and PFOS, individually. This standard will reduce exposure from these PFAS in our drinking water to the lowest levels that are feasible for effective implementation.
• For PFNA, PFHxS, and “GenX Chemicals,” the EPA is setting the MCLGs and MCLs at 10 parts per trillion.
• Because PFAS can often be found together in mixtures and research shows these mixtures may have combined health impacts, the EPA is also setting a limit for any mixture of two or more of the following PFAS: PFNA, PFHxS, PFBS, and “GenX Chemicals.”

The EPA is issuing this rule after reviewing extensive research and science on how PFAS affects public health, while engaging with the water sector and with state regulators to ensure effective implementation. EPA also considered 120,000 comments on the proposed rule from a wide variety of stakeholders.