Moderate-low record-based concern — Population-weighted indicator 82/100
State Overview
Water quality across Ohio receives an overall grade of B (Moderate-low record-based concern) with an average score of 82 out of 100, based on EPA compliance data from 859 ZIP codes statewide. This places Ohio 7 points above the national average of 75, indicating relatively strong water quality management across the state. Approximately 0% of ZIP codes (4 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.
Lowest Scoring ZIP Codes