Every public water system in the US — 433,698 (PWS × quarter) records from EPA Safe Drinking Water Act (SDWA). Per row: PWSID, name, type (Community Water System / Non-Transient Non-Community / Transient), source (Ground / Surface), owner type (Federal / Local / Private / Tribal / etc), population served, service connections, school/daycare flag, primacy agency, contact info, address.
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.