On March 11, 2021, the EPA proposed the fifth Unregulated Contaminant Monitoring Rule (UCMR 5) UCMR 5, which will require sample collection for 30 chemical contaminants, including PFAS. The testing will occur between 2023 and 2025 using analytical methods developed by EPA and consensus organizations.

The EPA uses the UCMR to collect data for contaminants that are suspected to be present in drinking water and do not have health-based standards set under the Safe Drinking Water Act (SDWA). This proposed action would provide the EPA, states, and communities with valid scientific data on the national presence of these contaminants in drinking water. The proposed UCMR 5 would provide new data that are vital in improving EPA’s understanding of the frequency of PFAS found in our nation’s drinking water systems and at what levels they are occurring.

The Proposed UCMR 5 scope, analytical methods and contaminants include assessment monitoring. As proposed, all public water systems serving 3,300 or more people and 800 representative PWSs serving fewer than 3,300, would collect samples for 29 per- and polyfluoroalkyl substances (PFAS) and lithium during a 12-month period at some point during the UCRM range dates of January 2023 through December 2025.

Merit Laboratories is a leading national PFAS environmental laboratory, analyzing drinking water, soil, wastewater, groundwater, and other sample matrices, including biosolids and sludge. Analytical methods performed by Merit for PFAS include drinking water by EPA 533, EPA 537.1, and EPA 537 rev. 1.1 and soil, wastewater, groundwater, and surface water by ASTM D7979-19 with Isotopic Dilution and ASTM D7968-17.