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Contaminant Candidate List (CCL) and Regulatory Determination

Regulatory Determination 2 for Contaminants on the Second Drinking Water Contaminant Candidate List

The Safe Drinking Water Act (SDWA), as amended in 1996, directs EPA to publish a list of contaminants (referred to as the Contaminant Candidate List, or CCL) to assist in priority-setting efforts. SDWA also directs the Agency to select five or more contaminants from the current CCL and determine whether to regulate these contaminants with a National Primary Drinking Water Regulation (NPDWR).

To regulate a contaminant SDWA requires that EPA determine whether:

  1. The contaminant may have an adverse effect on the health of persons;
  2. The contaminant is known to occur or there is a substantial likelihood the contaminant will occur in public water systems with a frequency and at levels of public health concern; and
  3. In the sole judgment of the Administrator, regulation of the contaminant presents a meaningful opportunity for health risk reductions for persons served by public water systems.
EPA published the second CCL (CCL 2) in 2005. In May 2007, the Agency published a Federal Register (FR) notice announcing and requesting comment on its preliminary determinations for 11 of the 51 CCL 2 contaminants. As part of this May 2007 FR notice, EPA also described the available health effects and occurrence information for perchlorate and stated that additional information was needed to more fully characterize perchlorate exposure and determine whether there was a meaningful opportunity for health risk reduction from a perchlorate regulation. In July 2008, and after careful consideration of public comments, EPA published its final determination that no regulatory action is appropriate or necessary for the following eleven contaminants:
  • Boron
  • Dacthal mono-acid (MTP) degradate
  • Dacthal di-acid (TPA) degradate
  • 1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE)
  • 1,3-Dichloropropene (Telone)
  • 2,4-Dinitrotoluene
  • 2,6-Dinitrotoluene
  • s-Ethyl propylthiocarbamate (EPTC)
  • Fonofos
  • Terbacil
  • 1,1,2,2-Tetrachloroethane

The Regulatory Determination 2 Schedule
Date Regulatory Determination
September 2004 Stakeholder meeting to provide a program update and to seek input from stakeholders on contaminants being considered for regulatory determinations.
May 2007 Announcement of Preliminary Regulatory Determinations for Priority Contaminants on the Second Drinking Water Contaminant Candidate List
May - June 2007

60 day public comment period

July 2008 Announcement of Final Regulatory Determinations for Priority Contaminants on the Second Drinking Water Contaminant Candidate List

July 2008 Final Regulatory Determinations for Priority Contaminants on the Second Contaminant Candidate List

Federal Register Notices and Fact Sheet

Support Documents for Regulatory Determination 2

Individual chapters and support documents are included by chapter number in the links below:
Regulatory Determination 2 Occurrence Data Support Documents