The EPA has determined that a national primary drinking water regulation (NPDWR) for perchlorate would not present ``a meaningful opportunity for health risk reduction for persons served by public water systems.'' The SDWA requires EPA to make determinations every five years of whether to regulate at least five contaminants on the Contaminant Candidate List (CCL). EPA included perchlorate on the first and second CCLs that were published in the Federal Register on March 2, 1998 and February 24, 2005. In this action, EPA presents supporting rationale and requests public comment on its preliminary regulatory determination for perchlorate. EPA will make a final regulatory determination for perchlorate after considering comments and information provided in the 30-day comment period following this notice. Comments must be received on or before November 10, 2008. POC is Eric Burneson, Office of Ground Water and Drinking Water, Standards and Risk Management Division, at (202) 564-5250 or e-mail burneson.eric@epa.gov (Federal Register: October 10, 2008, [Notices], Page 60262-60282)