WASHINGTON (Dec. 20, 2021) – Today, the U.S. Environmental Protection Agency (EPA) finalized the Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) to establish nationwide monitoring for 29 per- and polyfluoroalkyl substances (PFAS) and lithium in drinking water. This action is essential to addressing the public health and environmental risks of PFAS in drinking water and marks a significant milestone in EPA's PFAS Strategic Roadmap.