A

Lower record-based concern — Population-weighted indicator 86/100

Connecticut Drinking Water Quality Reports by ZIP Code

221 ZIP codes analyzed · Median 84 · Unweighted mean 82 · SDWIS 2026-07-21 · UCMR5 August 2026

State Overview

What the Connecticut water quality reports include

Water quality across Connecticut receives an record-only indicator of A (Lower record-based concern) with an average score of 86 out of 100, based on EPA compliance data from 221 ZIP codes statewide. A majority of ZIP codes (53%) earn an A grade, within this record-based model; this does not establish tap-water safety. The lowest-scoring area is ZIP code 06379 (Pawcatuck) with a score of 40/100. 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.

Choose a ZIP code below to review the public water systems associated with that area, five-year SDWIS violation history, available lead and copper results, UCMR5 PFAS occurrence records, enforcement actions and the limits of the geographic mapping. These reports describe public records, not the condition of water at an individual tap.

Search ZIP Code in Connecticut