The Environmental Protection Agency is looking to include a group of 29 per- and polyfluoroalkyl substances (PFAS), groups of disinfection byproducts (DBPs), cyanotoxins and scores of other individual chemicals on the latest iteration of its periodic Safe Drinking Water Act (SDWA) list of candidates for future regulations.
EPA’s proposed contaminant candidate list 5 (CCL5), released July 12, includes a total of 81 individual contaminants and groups of chemicals, the agency says in its Federal Register notice posted July 19. The list is comprised of 69 chemicals or chemical groups, including a group of 29 PFAS.
The SDWA requires EPA to develop periodic lists of contaminants not currently subject to drinking water standards and then make determinations for at least five contaminants from each list as to whether they should be regulated, based on a set of statutory criteria. However, the agency has issued few if any standards since Congress reformed the law in 1996, despite growing health concerns about exposures to some substances including PFAS, which are now subject to several state-specific drinking water standards alongside a push from several groups and a bipartisan coalition of lawmakers for federal rules.
The draft CCL5 also seems to mark a new step toward listing chemicals in groups rather than individually. While EPA has included some blocks of chemicals in previous CCLs, groups in the newly proposed list appear to combine many more individual substances for possible regulation than the agency sought in prior years.
EPA’s proposed listing of a group of PFAS, based on the substances’ structural similarities, appears to respond to calls from states and others who have long urged the agency to consider regulating either blocks of the chemicals or the entire category at once, saying that approach is a more efficient means of addressing a class whose constituent substances number in the thousands.
“These chemical groups have been identified as agency priorities and contaminants of concern for drinking water under other EPA actions. Listing these three chemical groups on the Draft CCL 5 does not necessarily mean that EPA will make subsequent regulatory decisions for the entire group,” the agency said in its initial notice. Instead, EPA says it will “evaluate scientific data on the listed groups, subgroups, and individual contaminants included in the group to inform any regulatory determinations for the group, subgroup, or individual contaminants in the group.”