The United States Environmental Protection Agency (EPA) has submitted final rules that affect businesses that manufactured or used PFAS substances and establish maximum contaminant levels (MCLs) for drinking water.

On April 19, 2024, the EPA submitted a final rule for publication that identifies two polyfluoroalkyl and perfluoroalkyl substances as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). These substances are PFOA and PFOS, two of the most common PFAS substances. In a related enforcement discretion policy, EPA clarified that it intends to focus enforcement on parties who significantly contributed to the release of PFAS compounds into the environment, including businesses that manufactured or used PFAS and other industrial parties. This designation requires immediate reporting of PFOA and PFOS releases into the environment, also imposes liability on responsible parties for past releases, and requires notification to purchasers of property about the storage, release, or disposal of these substances on the property.

On April 10, 2024, the EPA also finalized maximum contaminant levels (MCLs) for six PFAS compounds, which set legally enforceable levels in drinking water and set separate standards for PFAS mixtures containing at least two of four PFAS substances. EPA’s drinking water standards require public water systems to monitor for these substances by 2027 and engage in ongoing compliance monitoring. Beginning in 2027, drinking water systems must provide information to the public about the concentrations of these substances. By 2029, public water systems must implement procedures to reduce PFAS levels if monitoring shows that drinking water levels exceed these MCLs. Also in 2029, public water systems must inform the public if MCLs are exceeded and take steps to reduce levels of PFAS in their drinking water.