The U.S. Environmental Protection Agency (EPA) announced the Draft Fifth Contaminant Candidate List (CCL 5). These are contaminants that EPA is proposing to collect data about and evaluate whether national drinking water standards are warranted. EPA’s settlement with Waterkeeper Alliance anticipates EPA finalizing CCL5 by July 18, 2022. CCL 5 includes numerous chemicals and microbes that have appeared on CCL4 and prior CCLs. Importantly, the 66 individual chemicals, 12 microbes, and three groups in the proposed CCL5 include: Per-and polyfluoroalkyl substances as a broadly defined group (currently EPA describes this group so that it contains thousands of individual chemicals) Twenty-three named disinfection byproducts including previously listed nitrosamines, chlorate, and formaldehyde, but now including nitrosodibutylamine, two haloacetonitriles, three halonitromethanes, and six iodinated trihalomethanes Named cyanotoxins are consistent with previous CCLs but is now open to potentially other cyanotoxins The addition of Mycobacterium abscessus to previously listed Mycobacterium avium , and a new listing of Pseudomonas aeruginosa to the list of CCL microbial contaminants. The addition of lithium consistent with the continued inclusion of other contaminants for which UCMR data has been collected EPA did not include contaminants already addressed through regulatory determinations (PFOS; PFOA; 1,1-dichloroethane; acetochlor; methyl bromide (bromomethane); metolachlor; nitrobenzene; RDX; and strontium). EPA will seek comment on Draft CCL 5 for 60 days after publication of the notice in the Federal Register . Water systems should prepare for questions from customers and media regarding possible occurrence of listed contaminants and the extent of existing water treatment. Questions can be directed to Steve Via , AWWA’s director of federal relations.