US drinking water quality data by ZIP code — EPA violations, lead/copper levels, PFAS, radon, flood risk, and Home Safety Scores for 41,000+ ZIPs. 20 federal/state sources. Updated daily. CC BY 4.0.
Open-source Home Safety Score algorithm (0-100, A-F) for 41,000+ US ZIP codes. 20 data sources: EPA SDWIS/ECHO/LCR, PFAS, state MCLs, radon, FEMA flood, CDC blood lead, Census housing age. Powers zipcheckup.com
