Five steps to understand your utility's annual Consumer Confidence Report.
Find the MCL
The maximum contaminant level allowed by law.
Find the PHG
California's public health goal, often much lower than the MCL.
Compare the detected level to both
Look at the average and the range your utility measured.
Check the "Violations" section
Any violation must be listed and explained by your utility.
Look at the date
Reports come out once a year, usually by July 1.
Sample Consumer Confidence Report
Illustrative example only — not real data.
Substance | Units | 1MCL | 2PHG | 3Detected (range) | 4Violation | Typical source | 5Year |
|---|---|---|---|---|---|---|---|
| Arsenic | ppb | 10 | 0.004 | 2.1 (ND–4.0) | No | Natural deposits | 2025 |
| Nitrate (as N) | ppm | 10 | 10 | 3.2 (1.1–5.6) | No | Fertilizer runoff | 2025 |
| Fluoride | ppm | 2 | 1 | 0.7 (0.6–0.8) | No | Water additive | 2025 |
| Hardness | ppm | — | — | 210 (180–240) | No | Natural minerals | 2025 |
A detection is not a violation. Many substances are present at levels far below limits.
Find your utility's report: www.epa.gov/ccr
California Drinking Water Watch: sdwis.waterboards.ca.gov/PDWW