C

Mixed record-based signals — Population-weighted indicator 70/100

Water Quality in Mississippi

272 ZIP codes analyzed · Median 78 · Unweighted mean 77 · Data updated July 2026

State Overview

About Water Quality in Mississippi

Water quality across Mississippi receives an overall grade of C (Mixed record-based signals) with an average score of 70 out of 100, based on EPA compliance data from 272 ZIP codes statewide. This is 5 points below the national average of 75, suggesting significant water quality challenges that affect residents statewide. Approximately 5% of ZIP codes (13 areas) receive a D or F grade, indicating communities with notable water quality concerns that warrant attention. Scores are calculated from EPA Safe Drinking Water Information System (SDWIS) violation records, lead and copper testing results, PFAS monitoring data from UCMR5, and enforcement actions over the past 5 years.

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