Perchlorate Notice [2040-AF02 / 2040-AF08]

The Safe Drinking Water Act (SDWA) requires EPA to make determinations every five years of whether to regulate at least five contaminants on its Contaminant Candidate List (CCL). A regulatory determination is a formal decision on whether EPA should initiate a rulemaking process to develop a national primary drinking water regulation for a specific contaminant. EPA included perchlorate on the first and second CCLs that were published in the Federal Register on March 2, 1998 and February 24, 2005 (70 FR 9071 (USEPA, 2005a)). On October 10, 2008, EPA published a preliminary regulatory determination for perchlorate in drinking water. EPA received comments from over 32,000 individuals and organizations in response to this notice. EPA has reviewed the information in these comments and has re-evaluated the scientific information regarding the perchlorate regulatory determination. To assure transparency in its decision making process, EPA will request comment on its re-evaluation of the scientific data. EPA will make a final determination for perchlorate after review and consideration of public comments received on the supplemental request for comment.