EPA: Recommendations for enhanced monitoring for Hexavalent Chromium (Chromium-6) in Drinking Water
Ensuring safe drinking water for all is a top priority for EPA, state drinking water agencies, and drinking water systems across the country. National primary drinking water regulations set the maximum contaminant level (MCL) of 0.1 mg/L for total chromium, which includes chromium-6 (hexavalent chromium), and requires community and non-transient non-community water systems to test for chromium at the entry point to the distribution system. The chromium standard was established in 1991 based on the best available science.
EPA regularly re-evaluates drinking water standards; a rigorous and comprehensive review of chromium-6 health effects began following the release of the toxicity studies by the National Toxicology Program in 2008. In September, 2010, EPA released a draft of the scientific assessment (Toxicological Review of Hexavalent Chromium) for public comment and external peer review. When this human health assessment is finalized in 2011, EPA will carefully review the conclusions and consider all relevant information to determine if a new standard needs to be set.