Officials said the contaminants either don't occur nationally in public water systems, or occur at levels that don't pose a health concern, the EPA said in a news release.

The determination was based on a review of health effects, occurrence data and public comment, the agency said.

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

The contaminants include naturally occurring substances, pesticides, herbicides and chemicals currently or formerly used in manufacturing, Grumbles said.

While the contaminants weren't occurring nationally, EPA officials said they are updating health advisories for seven contaminants for local officials in situations where the contaminants may be present. The contaminants are boron; dacthal mono- and di-acid degradates; 1,3-dichloropropene (Telone); 2,4-dinitrotoluene, and 2,6-dinitrotoluene; and 1,1,2,2-tetrachloroethane.

Officials determined updated or new advisories were not needed for 1-dichloro-2,2-bis(p-chlorophenyl) ethylene; s-ethyl propyl thiocarbamate; Fonofos and Terbacil.