On July 19, 2021, the U.S. Environmental Protection Agency (EPA) published a Federal Register notice containing a draft list of contaminants that are currently not subject to any Safe Drinking Water Act regulations, but may be in the future due to their known or anticipated occurrence in public drinking water systems. The list, which is referred to as the Fifth Contaminant Candidate List (CCL 5), includes 66 chemicals representing three broad groups (PFAS, disinfection byproducts, and cyanotoxins). The list also includes 12 microbial contaminants. PFAS substances are proposed as a group, with the exception of PFOA and PFOS because EPA is moving forward with national primary drinking water standards for these two contaminants. The list also contains 1,4-Dioxane, which is used as a stabilizer for chlorinated solvents such as trichloroethane and trichloroethylene. 1,4-Dioxane is also an unintended contaminant of chemical ingredients used in many personal care products such as bubble bath, shampoo, soap, skin cleanser, and other consumer products such as adhesives and antifreeze. Even foods may contain trace amounts of 1,4-dioxane from some additives and packaging materials. As a result, some states have begun to regulate this chemical. New York was the first to regulate 1,4-Dioxane by establishing a maximum contaminant level of 1 part per billion.


EPA plans to consult with the Science Advisory Board (SAB) on the Draft CCL 5 in the Fall of 2021. Additionally, the Agency will consider public comments in developing the Final CCL 5 list, which is expected to be published in July 2022. Comments on the list of contaminants must be received on or before September 17, 2021. Comments should be identified by Docket ID Number EPA–HQ–OW–2018–0594 and can be submitted via the Federal eRulemaking Portal. This submission is the Agency’s preferred method, although comments can also be submitted via U.S. mail to: U.S. Environmental Protection Agency, EPA Docket Center, Water Docket, Environmental Protection Agency, Mail code: 28221T, 1200 Pennsylvania Ave. NW, Washington, DC 20460. More information about the CCL 5 list is available on EPA’s website HERE.