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Contaminant Occurrence Data for Six-Year Review of Drinking Water Standards

To support the national contaminant occurrence and exposure assessments performed under the Six-Year Review process, EPA analyzes compliance monitoring data from public water supplies for regulated drinking water contaminants. This analysis allows EPA to characterize the frequency of occurrence, the levels found, and the geographic distribution of contaminants to help the Agency determine if there may be a meaningful opportunity to improve public health protection. EPA maintains occurrence data on the web for the time period used in the most recent Six-Year Review.

Download occurrence data that was collected to evaluate regulated contaminant levels in drinking water: