Every recent or unresolved Safe Drinking Water Act violation — 743,600 violations from EPA SDWIS (2015+ or any status != Resolved). Per violation: violation ID, PWSID (joins epa_sdwa_water_systems), compliance period begin/end, contaminant code, violation code + category, health-based flag, major violation flag, measured value + unit, federal/state MCL, public notification tier, rule code/group/family, severity count, RTC date, violation status (Resolved/Unaddressed/Archived). Also: 433,150 SDWIS site visits per PWSID with reason + agency type.
Every record in this dataset can be traced back to its primary source at https://echo.epa.gov/tools/data-downloads. Underlying content is a US federal government work (public domain under 17 USC §105); our derived data is licensed CC0 1.0.