Announcement of Final Regulatory Determinations for Contaminants on the Fourth Drinking Water Contaminant Candidate List

The U.S. Environmental Protection Agency (EPA or Agency) is announcing final regulatory determinations for eight of the 109 contaminants listed on the Fourth Contaminant Candidate List. Specifically, the Agency is making final determinations to regulate perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) and to not regulate 1,1-dichloroethane, acetochlor, methyl bromide (bromomethane), metolachlor, nitrobenzene, and RDX. The Safe Drinking Water Act (SDWA), as amended in 1996, requires EPA to make regulatory determinations every five years on at least five unregulated contaminants. A regulatory determination is a decision about whether or not to begin the process to propose and promulgate a national primary drinking water regulation for an unregulated contaminant.