The U.S. Environmental Protection Agency recently published its Final Fifth Drinking Water Contaminant Candidate List (CCL 5), which will serve as the basis for the agency’s regulatory considerations over the next five-year cycle under the Safe Drinking Water Act. This update includes a substantial expansion of per- and polyfluoroalkyl substances (PFAS), a first step towards identifying additional PFAS that may require regulation under the Safe Drinking Water Act.

“Following public engagement and robust scientific review, the final contaminant candidate list is the latest milestone in our regulatory efforts to ensure safe, clean drinking water for all communities,” says EPA Assistant Administrator for Water Radhika Fox. “As EPA takes action to protect public health and the environment from PFAS, including proposing the first nationwide drinking water standards later this year, today’s final CCL 5 looks further forward to consider additional protective steps for these forever chemicals.”

A year ago, the EPA published the PFAS Strategic Roadmap, outlining an agency-wide approach to addressing PFAS in the environment. This recent announcement supports its decision-making for potential future regulations of PFAS.

In addition to a group of PFAS, the Final CCL 5 includes 66 individually listed chemicals, two additional chemical groups (cyanotoxins and disinfection byproducts), and 12 microbes.

In developing the Final CCL 5, the EPA requested public nominations, providing an opportunity for people to make recommendations to the agency about specific contaminants of concern that may disproportionately affect their local community. The EPA further enhanced the CCL process based on comments received on this CCL and previous CCLs, including by prioritizing data most relevant to drinking water exposure, improving considerations of sensitive populations including children, and considering the recommendations included in the review of the EPA’s Draft CCL 5 report from the Science Advisory Board. These improvements resulted in a Final CCL 5 that can better inform prioritization of contaminants for potential regulatory actions and/or research efforts. Visit the EPA’s website for more information on the final CCL 5.