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Contaminant Occurrence and Related 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, the estimated population exposure, 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 compliance monitoring data that were collected to evaluate regulated contaminant levels in drinking water:

In addition, EPA also analyzed information from supplemental sources to help support the Six Year Review 3. Select the link below to read a short description of these supplemental data sources and to download available data.