Six-Year Review of Drinking Water Standards

  • Six-Year Review

    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. Revisions must maintain or strengthen public health protection. Learn more about the major elements of the review.

As part of the "Six-Year Review," EPA evaluates any newly available data, information and technologies to determine if any regulatory revisions are needed.

What EPA Considers During Reviews

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Contaminant Occurrence in Drinking Water

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Last updated on March 23, 2025