EPA is beginning the development of the fifth Contaminant Candidate List (CCL 5). 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 listed on the CCL may require future regulation under the Safe Drinking Water Act (SDWA). 

On October 4, 2018, EPA  requested nominations of chemicals, microbes, or other materials for consideration on the CCL 5. The public was able to nominate contaminants by following the instructions contained in the Federal Register notice for CCL 5 nominations. The deadline for nominations was December 4, 2018, so is now closed. EPA is evaluating the nomiminations and other contaminant data and information and plans to publish a draft CCL 5 for public review and comment.

• Federal Register Notice: Request for Nominations of Drinking Water Contaminants for the Fifth Contaminant Candidate List