Regulatory Determination 4

The Safe Drinking Water Act (SDWA) directs EPA to publish a list of contaminants (referred to as the Contaminant Candidate List, or CCL) to assist in priority-setting efforts. The SDWA also directs EPA to select no fewer than five contaminants from the current CCL and determine whether to regulate these contaminants with a National Primary Drinking Water Regulation (NPDWR). A regulatory determination is a decision on whether EPA should initiate a rulemaking process to develop an NPDWR for a specific contaminant. Learn more.

Final Regulatory Determinations for CCL 4

On February, 22, 2021, EPA reissued final regulatory determinations for contaminants on the Fourth Contaminant Candidate List (CCL 4). EPA is making final determinations to regulate two contaminants, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), in drinking water and to not regulate six contaminants (i.e., 1,1-dichloroethane, acetochlor, methyl bromide (bromomethane), metolachlor, nitrobenzene, and RDX). With the final Regulatory Determinations for PFOA and PFOS, EPA will move forward to implement the national primary drinking water regulation development process for these two PFAS. The Regulatory Determinations also outline avenues that the agency is considering to further evaluate additional PFAS chemicals and provide flexibility for the agency to consider groups of PFAS as supported by the best available science.

Supporting Materials 

• Federal Register Notice: Announcement of Final Regulatory Determinations for the Fourth Drinking Water Contaminant Candidate List
• Technical Support Documents for Final Regulatory Determinations 4 are available on www.regulations.gov: Docket ID No. EPA-HQ-OW-2019-0583.  
• Press Release: EPA Takes Action to Address PFAS in Drinking Water
• Infographic: Understanding How EPA Develops New Drinking Water Regulations
• SDWA Evaluation and Rulemaking Process
• Information on PFAS

Preliminary Regulatory Determinations for CCL 4

On February 20, 2020, EPA announced and requested public comment on the preliminary regulatory determinations for eight CCL 4 contaminants. EPA made preliminary determinations to regulate PFOS and PFOA in drinking water and to not regulate six contaminants (i.e., 1,1-dichloroethane, acetochlor, methyl bromide (bromomethane), metolachlor, nitrobenzene, and RDX).

Supporting Materials 

• Federal Register Notice: Announcement of Preliminary Regulatory Determinations for the Fourth Drinking Water Contaminant Candidate List
• Federal Register Notice: Comment Extension for Preliminary Regulatory Determinations for the Fourth Drinking Water Contaminant Candidate List
• Press Release: EPA Announces Proposed Decision to Regulate PFOA and PFOS in Drinking Water
• Technical Support Documents for Preliminary Regulatory Determinations 4 are available on www.regulations.gov: Docket ID No. EPA-HQ-OW-2019-0583.