Illinois Drinking Water Quality Reports by ZIP Code

State Overview

What the Illinois water quality reports include

Water quality across Illinois receives an record-only indicator of C (Mixed record-based signals) with an average score of 64 out of 100, based on EPA compliance data from 874 ZIP codes statewide. Approximately 2% of ZIP codes (21 areas) receive a D or F grade, indicating communities with notable water quality concerns that warrant attention. The lowest-scoring area is ZIP code 61752 (Le Roy) with a score of 35/100. 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.