EPA published the Final Fifth Drinking Water Contaminant Candidate List (CCL 5), which will serve as the basis for EPA'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), an important first step towards identifying additional PFAS that may require regulation under the Safe Drinking Water Act. In addition to a group of PFAS, the Final CCL 5 includes 66 individually listed chemicals, two additional chemical groups (cyanotoxins and disinfection byproducts (DBPs)), and 12 microbes.