Poor — Average Score 59/100
State Overview
Water quality across Oklahoma receives an overall grade of D (Poor) with an average score of 59 out of 100, based on EPA compliance data from 627 ZIP codes statewide. This is 16 points below the national average of 75, suggesting significant water quality challenges that affect residents statewide. Approximately 45% of ZIP codes (281 areas) receive a D or F grade, indicating communities with notable water quality concerns that warrant attention. The lowest-scoring area is ZIP code 73068 (Noble) with a score of 22/100. 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