EPA’s Final Unregulated Contaminant Monitoring Rule 5 to Include an Expanded List of PFAS Constituents and Additional Public Water Systems
The Safe Drinking Water Act (SDWA), as amended in 1996, requires that EPA establish a program to monitor specified unregulated contaminants every five years from Public Water Systems (PWS). The monitoring effort historically consisted of data collection from large PWS systems (serving > 10,000 people) and representative small PWS serving less than or equal to 10,000 people. EPA published the first Unregulated Contaminant Monitoring Rule (UCMR) in 1999. More than two decades later, EPA has now finalized its 5th cycle of unregulated contaminant monitoring under the now final UCMR 5. EPA published its final Rulemaking on December 27, 2021 with an effective date of January 26, 2022.
The data collected through UCMR 5 will be stored in the National Contaminant Occurrence Database and will be used to support the EPA Administrator’s determination as to whether regulation of previously unregulated contaminants is warranted. The selection of contaminants in the final UCMR 5 cycle is based on a review of the Contaminant Candidate List (CCL), which is a list of contaminants that are not currently regulated by EPA under the national drinking water regulations.
As part of the final UCMR 5 rulemaking, EPA will now require monitoring for 29 different types of Per- and Polyfluoroalkyl Substances (PFAS) as well as lithium. The final UCMR 5 preparation and monitoring period will cover the years 2022- 2026. The inclusion of an expanded list of PFAS in the UCMR 5 fulfills a key commitment in EPA's 2021 PFAS Strategic Roadmap by requiring the collection of more drinking water occurrence data for a broader group of PFAS, utilizing analytical methods at lower minimum reporting levels than previously possible (e.g., EPA Method 533 and EPA Method 537.1).
Also of importance to the UCMR 5 rulemaking efforts, the SDWA amendments under P.L. 115–270, known as America’s Water Infrastructure Act of 2018 (AWIA), expanded unregulated contaminant monitoring requirements to include all smaller PWS serving 3,300-10,000 individuals. The final Rule includes these smaller PWS systems in the data collection effort, however, provisions in the final Rule enable the EPA to adjust the number of these smaller systems which must monitor based on available Congressional appropriations. As of now, Congress has not appropriated additional funding to support the UCMR monitoring at these smaller PWS. EPA anticipates that over 9,000 large and smaller PWS will ultimately participate in the PFAS-focused data collection effort.