PFAS National Drinking Water Assessment Monitoring: UCMR3 and UCMR5 Comparison

Drinking Water
Oral Presentation

Prepared by Y. Li
Eurofins Eaton Analytical, LLC, 50510 West Abbey Drive, Granger, IN, 46530, United States

Contact Information: [email protected]; 574-472-5562


Global drinking water supplies have become increasingly vulnerable to per- and polyfluoroalkyl substances (PFAS) from industrial discharges, fire-fighting activities, wastewater discharges, landfill leachates, biosolids, air emissions, etc. Human exposure to PFAS contamination is a growing and probably never-ending worldwide public health issue.

In the United States, the Environmental Protection Agency (EPA) conducted the first national drinking water assessment monitoring on six high priority PFAS through the Third Unregulated Contaminant Monitoring Rule (UCMR3) during 2012-2016. With the designated minimum reporting levels (MRLs) of 20 ng/L for PFOA and 40 ng/L for PFOS, approximately 1% of 36,972 samples and 2% of 4,920 participating public water systems (PWS) across 36 states were detected positive for PFOA and/or PFOS. Following the UCMR3, several states have established, recommended, or proposed drinking water compliance standards as individual PFAS or the sums of selected PFAS. These state maximum contaminant levels (MCLs) or health-based values (HBVs) are generally lower than the lifetime drinking water health advisories of 70 ng/L for PFOA and/or PFOS established by EPA in 2016. As expected, EPA may propose the national drinking water MCLs of PFOA and PFOS in late 2022. The new national drinking water assessment monitoring through the Unregulated Contaminant Monitoring Rule (UCMR5) will analyze 29 PFAS during the primary sampling period of 2023-2025.

In this presentation, we will first present a UCMR3 and UCMR5 comparison in terms of monitoring scopes, analytical methods, analytes and minimum reporting levels (MRLs), sampling and requirements, reporting data, and approved laboratories as well. Secondly, we will present a close estimate on the elevated detection of UCMR5 PFAS through data mining of our large PFAS occurrence database. It is our expectation that this presentation will be helpful in implementing UCMR5, understanding the wide spread occurrence of PFAS contamination in drinking water supplies, planning and executing appropriate PFAS control and remediation actions, and establishing future drinking water PFAS regulations.