A

Lower record-based concern — Population-weighted indicator 88/100

Water Quality in Wyoming

48 ZIP codes analyzed · Median 87 · Unweighted mean 83 · Data updated July 2026

State Overview

About Water Quality in Wyoming

Water quality across Wyoming receives an overall grade of A (Lower record-based concern) with an average score of 88 out of 100, based on EPA compliance data from 48 ZIP codes statewide. This places Wyoming 13 points above the national average of 75, indicating relatively strong water quality management across the state. A majority of ZIP codes (69%) earn an A grade, reflecting strong compliance across most water systems. 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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