The U.S. Environmental Protection Agency has made a final determination not to regulate 11 contaminants on the second drinking water contaminant candidate list (CCL 2). The agency has concluded that the contaminants do not occur nationally in public water systems, or occur at levels below a public health concern. The agency's final regulatory determination is based on extensive review of health effects, occurrence data and public comments.

"Sound science and public health drive EPA's decisions under the Safe Drinking Water Act," said Benjamin H. Grumbles, EPA's assistant administrator for water. "We will continue to thoroughly review new and emerging contaminants to ensure that citizens and our environment are protected."

The 11 contaminants include naturally occurring substances, pesticides, herbicides, and chemicals used (or once used) in manufacturing. While none of the contaminants were found nationally at levels of public health concern in public water systems, EPA is updating health advisories for seven of the contaminants to provide current health information to local officials for situations where the contaminants may be present.

EPA is updating health advisories for boron; dacthal mono- and di-acid degradates;1,3-dichloropropene (Telone); 2,4-dinitrotoluene, and 2,6-dinitrotoluene; and 1,1,2,2-tetrachloroethane. EPA has determined that updated or new health advisories are not needed for 1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE); s-ethyl propyl thiocarbamate (EPTC); Fonofos; and Terbacil, because the national monitoring data showed almost no occurrence at levels of public health concern.

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. Under the Safe Drinking Water Act, every five years EPA develops a CCL and then makes a regulatory determination for at least five contaminants on the list. In 2005, the agency published the second CCL, which listed 51 contaminants. In May 2007, EPA requested public comment on its preliminary regulatory determinations not to regulate 11 of these 51 CCL 2 contaminants.