On April 02, 2026, the Environmental Protection Agency (EPA) published its draft Sixth Contaminant Candidate List (CCL 6). The CCL is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations but are known or anticipated to occur in public water systems. Contaminants included on the CCL may experience future regulation under the Safe Drinking Water Act (SDWA).

The CCL 6 draft includes 75 chemicals spanning four chemical groups (microplastics, pharmaceuticals, per- and polyfluoroalkyl substances (PFAS), and disinfection byproducts) and 9 microbes.

EPA Administrator Lee Zeldin said the inclusion of these chemicals on the draft CCL 6 isEPA’s response to Americans who have expressed concerns about plastics and pharmaceuticals in their drinking water. The gesture also aims to hand a win to Health Secretary Robert F. Kennedy Jr.’s MAHA movement, which for months has pressured Zeldin to further crack down on environmental contaminants.

The publication of the draft CCL 6 opened a 60-day public comment period to discuss the contents of the list and the process used to select the contaminants. Public comments are due by June 01, 2026, and the EPA expects to finalize the list by mid-November.

Effects and Takeaways

The inclusion of microplastics, PFAS, and pharmaceuticals on the list gives EPA and local regulators a tool to evaluate risks in their water supply, so CCL 6 will set the stage for more research and regulatory action, but such action is not guaranteed to come. For instance, just last month, EPA announced it would not be taking any regulatory actions related to nine chemicals that were listed on the fifth CCL.

Therefore, every stakeholder with an interest in the regulation of these chemicals and the process leading to their listing on the draft CCL 6 should consider monitoring and engaging in the open public comment period.

For assistance with government relations, including drafting public comments and other environmental matters, please contact CMBG3 Law and our environmental team. Our team is ready to provide guidance on regulatory issues, policy changes, and compliance concerns.