California Drinking Water Quality Reports by ZIP Code

State Overview

What the California water quality reports include

Water quality across California receives an record-only indicator of A (Lower record-based concern) with an average score of 92 out of 100, based on EPA compliance data from 1354 ZIP codes statewide. A majority of ZIP codes (82%) earn an A grade, within this record-based model; this does not establish tap-water safety. The lowest-scoring area is ZIP code 93614 (Coarsegold) with a score of 48/100. 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.