EPA’s new data could sharpen public focus on PFAS

The U.S. Environmental Protection Agency (EPA) has shared the first of 12 batches of per- and polyfluoroalkyl substances (PFAS) data collected as part of the Fifth Unregulated Contaminant Rule (UCMR 5).

While the new data helps sharpen the picture of PFAS contamination across the U.S., the release represents just 7 percent of the total to be collected by 2026, the EPA says.

“EPA is conducting the most comprehensive monitoring effort for PFAS ever at every large and midsize public water system in America and at hundreds of small water systems,” EPA Assistant Administrator for Water Radhika Fox says.

 In the meantime, policymakers, water suppliers and reclamation facilities, as well as the public at large, await a final National Primary Drinking Water Regulation (NPDWR), expected for final publication later this year, the EPA says.

The current minimum reporting levels (MRLs) for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are set at 4 parts per trillion (ppt), which is the same concentration as the proposed maximum contaminant levels (MCLs).

“It’s not surprising that a greater proportion of public water supplies have detections of PFOS and PFOA as part of UCMR 5 as compared to UCMR 3,” CDM Smith PFAS Practice Leader Ian Ross says.

The MRLs for UCMR 3 were significantly higher, and when the 2016 health advisory level (70 ppt) was applied to the UCMR 3 data, this led to 0.4 percent of public water supplies being out of compliance in 2016. If the proposed MCLs (4 ppt PFOS and PFOA) are promulgated, comparing this to the first 7% of the UCMR 5 data, this may result in about 8% of public drinking water supplies being out of compliance.

“When setting MCLs and health advisories for PFOS and PFOA, the existing ambient concentrations should be reviewed,” Ross says. “There have been detections of 50 ppt of PFOS and 30 ppt of PFOA in rain across the U.S., which is an order of magnitude higher than the proposed MCLs. It may be difficult to expect that some drinking water can avoid detections of PFOS and PFOA with these elevated ambient concentrations in rain.”

When considering a wider range of PFAS, there have been detections of 16,400 ppt of PFAS in rain in Ohio, indicating the multitude of uses and emissions, CDM Smith says.

As announced in the Effluent Guidelines Program Plan 15 in January 2023, the EPA has completed a detailed study of landfill discharge. Based on the information and data collected through this study, the EPA says it plans to develop effluent guidelines for landfills. The EPA intends to revise the existing Landfills Point Source Category effluent limitations guidelines to address PFAS discharge from these landfills.

Community water systems required to monitor under UCMR must inform their customers of UCMR results (including the average and range of results) in their annual Consumer Confidence Report (CCR). According to EPA’s announcement about the data release, water utilities should be ready for increased news reports and customer inquiries about PFAS and lithium stemming from this data release.

According to the pending regulation, water systems would be able to use results from UCMR 5 to fulfill the NPDWR initial monitoring requirements, Boston-based CDM Smith says in a news release.

Published in December 2021, UCMR 5 requires water systems to test for 29 PFAS and lithium between 2023 and 2025 using analytical methods developed by the EPA and other consensus organizations.

MRLs are the lowest detectable concentration of a contaminant that is considered achievable with 95 percent confidence by at least 75 percent of laboratories nationwide using a specified analytical method, CDM Smith says. The goal of the MRL approach is to create a consistent, high‐quality UCMR dataset using results reported by many laboratories across the country. MRLs are not associated with contaminant health effects information.