Free Water Quality Reports
Instant water quality grades for 29,542 US ZIP codes. Powered by EPA data, PFAS monitoring, and violation records.
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National Overview
Every ZIP code receives a grade from A to F based on contaminant levels, PFAS detections, violation history, and enforcement actions.
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US Water Score aggregates publicly available water quality data from the EPA's Safe Drinking Water Information System (SDWIS), the Unregulated Contaminant Monitoring Rule (UCMR5) for PFAS, and enforcement records. We analyze data from over 96,000 community water systems serving 300+ million Americans.
Grades are calculated using a weighted scoring algorithm that considers: violation count and severity (log-scaled), lead and copper 90th percentile levels, PFAS detections and MCL exceedances, and enforcement history. Scores range from 0–100 and map to letter grades A through F.
This site provides water quality information for educational purposes only. Data may not reflect current conditions. Always contact your local water utility or review your annual Consumer Confidence Report for the most up-to-date information. This is not medical or legal advice.