Six-Year Review of Drinking Water Standards

The Safe Drinking Water Act (SDWA) requires EPA to review each national primary drinking water regulation at least once every six years and revise them, if appropriate. As part of the "Six-Year Review," EPA evaluates any newly available data, information and technologies to determine if any regulatory revisions are needed. Revisions must maintain or strengthen public health protection.

Recent and Past
Six-Year Reviews


What EPA Considers in
Conducting Reviews

Contaminant Occurrence in Drinking Water Systems

What Contaminants are Currently Regulated?