B

Good — Average Score 76/100

Water Quality in Maine

216 ZIP codes analyzed · Data updated March 2026

State Overview

About Water Quality in Maine

Water quality across Maine receives an overall grade of B (Good) with an average score of 76 out of 100, based on EPA compliance data from 216 ZIP codes statewide. This is roughly in line with the national average of 75. Approximately 14% of ZIP codes (30 areas) receive a D or F grade, indicating communities with notable water quality concerns that warrant attention. The lowest-scoring area is ZIP code 04901 (Waterville) with a score of 28/100. 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.

Search ZIP Code in Maine