On April 6, 2026, EPA proposed a list of contaminants to be included in its sixth Contaminant Candidate List (CCL), including “microplastics, pharmaceuticals, per- and polyfluoroalkyl substances (PFAS), disinfection byproducts, as well as 75 chemicals and nine microbes.” Contaminants listed in the CCL are prioritized by EPA for research and data collection efforts but are not necessarily regulated by national primary drinking water regulations. This is the first time microplastics have been listed as a contaminant group in the CCL. Comments can be submitted until June 5, 2026.