2020-04145: Announcement of Preliminary Regulatory Determinations for Contaminants on the Fourth Drinking Water Contaminant Candidate List

Summary

The Safe Drinking Water Act (SDWA), as amended in 1996, requires the Environmental Protection Agency (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 (NPDWR) for an unregulated contaminant. A preliminary regulatory determination lays out and takes comment on EPA's view about whether certain unregulated contaminants meet three statutory criteria. After EPA considers public comment, EPA makes a final determination. The unregulated contaminants included in a regulatory determination are chosen from the Contaminant Candidate List (CCL), which the SDWA requires the EPA to publish every five years. The EPA published the fourth CCL (CCL 4) in the Federal Register on November 17, 2016. This document presents the preliminary regulatory determinations and supporting rationale for the following eight of the 109 contaminants listed on CCL 4: Perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), 1,1-dichloroethane, acetochlor, methyl bromide (bromomethane), metolachlor, nitrobenzene, and Royal Demolition eXplosive (RDX). The Agency is making preliminary determinations to regulate two contaminants (i.e., PFOS and PFOA) and to not regulate six contaminants (i.e., 1,1-dichloroethane, acetochlor, methyl bromide, metolachlor, nitrobenzene, and RDX). The EPA seeks comment on these preliminary determinations. The EPA is also presenting an update on three other CCL 4 contaminants (strontium, 1,4-dioxane, and 1,2,3- trichloropropane).

The agency’s own summary, as published.

What this changes

Amends 1 part of the Code of Federal Regulations — the standing rules this notice rewrites.

• 40 CFR 141 National Primary Drinking Water Regulations