U.S. EPA Finalizes Fifth UCMR—PFAS Remain In The Regulatory Bullseye

On December 20, 2021, U.S. EPA finalized its Fifth Unregulated Contaminant Monitoring Rule (UCMR) that will require public water systems (PWS) to collect monitoring data for 29 per- and polyfluoroalkyl substances (PFAS) and lithium in drinking water. Every five years, the Safe Drinking Water Act (SDWA) requires U.S. EPA to publish a new list of unregulated contaminants that will be monitored by PWS.  UCMR 5 focuses almost exclusively on PFAS and targets 29 of the more than 4,700 PFAS that have been identified to date. 

Starting in 2023, all PWSs serving more than 10,000 customers are obligated to monitor for these UCMR 5 contaminants while smaller PWSs (those serving less than 10,000 customers) must monitor subject to availability of appropriations (U.S. EPA is responsible for all analytical costs associated with PWSs serving less than 10,000 customers) and laboratory capacity. In response to comments on the draft UCMR 5 expressing concern about the lack