The US Environmental Protection Agency will soon collect data on 30 unregulated chemicals in drinking-water systems, including ultrashort per- and polyfluoroalkyl substances (PFAS) and pesticides, according to a proposal announced on June 26 by the agency and published in the Federal Register on July 1.
“The information we collect through this important monitoring effort will inform the agency’s future decisions to protect drinking water for Americans nationwide,” EPA assistant administrator for the Office of Water Jessica Kramer says in a press release.
The proposal is the sixth edition of the Unregulated Contaminant Monitoring Rule (UCMR), which is updated every 5 years to monitor contaminants in public water systems, contaminants that may require future regulation under the Safe Drinking Water Act. The updated UCMR includes 7 ultrashort PFAS, including trifluoroacetic acid (TFA), 3 pesticide metabolites, 13 semivolatile organic compounds, and 7 purgeable organic compounds. The list excludes microplastics, frustrating some critics.
Democratic leaders and advocacy groups, including 7 governors (PDF), 15 attorneys general (PDF), and 176 organizations (PDF), sent letters to the EPA over the last 2 years urging the agency to include microplastics in the new UCMR. The agency added microplastics to their latest Contaminant Candidate List in April, a precursor to the UCMR, and announced they would address microplastic contamination in drinking water.
The move to leave out microplastics from the rule has frustrated some organizations, like the Plastic Pollution Coalition. “Omitting microplastics monitoring for the next five years is a serious failure to protect public health,” Rachel Bustamante, policy manager at the Plastic Pollution Coalition, writes in an email to C&EN. “Despite the EPA’s pledge to ‘protect Americans’ from ‘one of the most urgent and growing public health challenges,’ this proposal leaves the public in the dark about what’s in their drinking water.”
Chris Rager, vice president of government affairs at the Plastics Industry Association, writes in an email to C&EN that “EPA’s proposed UCMR-6 appropriately reflects the current state of the science.” The Contaminant Candidate List includes microplastics, “even though there is no scientific testing procedure for public water systems to reliably monitor microplastics in drinking water.” By excluding microplastics from the UCMR, Rager writes, EPA regulators “have concluded that the scientific evidence does not support finding a human health concern while continuing to encourage additional research.”
The proposed rule includes for the first time ultrashort-chain PFAS, which Katie Pelch, a senior scientist at the Natural Resources Defense Council, is pleased to see. “Some of these chemicals are already known to be widely detected in the environment and to be harmful to human health,” she writes in an email to C&EN. Still, she points out, the reporting limits for the ultrashort-chain PFAS are higher than reporting limits available for commercial laboratories. “This could result in the data that is collected being less informative and likely underestimating the extent of the contamination.”
When the EPA decided to first collect data on PFAS in drinking water, in the third UCMR, Pelch writes, the reporting limits of PFAS were too high, so the extent of contamination in drinking water “was downplayed.” She says that was remedied in the fifth UCMR. That rule included 29 PFAS and was finalized and implemented under the Joe Biden administration. The results ultimately led to drinking-water regulations for four PFAS, which the current EPA is moving to rescind.
The EPA did not respond to questions from C&EN about PFAS reporting limits or their decision to exclude microplastics from the rule. The agency is soliciting public comments until Aug. 31 and will hold two virtual public meetings during this period, on Aug. 11 and Aug. 12.
C&EN reached out to the American Water Works Association and the Association of Metropolitan Water Agencies for comment and did not hear back by publication time.
