How to Read Your Arizona Water Quality Report
Every community water system must publish an annual Consumer Confidence Report (CCR), required under the federal Safe Drinking Water Act. Arizona city reports usually come out mid-year. Search "[your city] water quality report".
Key terms
- MCL: Maximum Contaminant Level, the highest level legally allowed.
- MCLG: the level below which there's no known health risk. It can be lower than the MCL.
- AL (Action Level): a trigger for extra treatment, used for lead and copper.
- ppm / ppb: parts per million / billion. 1 ppm = 1 mg/L.
- ND: none detected.
- gpg: grains per gallon of hardness (1 gpg ≈ 17.1 ppm).
How to read a results row
- Find the contaminant and its unit.
- Compare the "average" or "highest level detected" with the MCL.
- Look at the range. Your tap may be closer to the high or the low end.
- Read the "likely source" column, for example erosion of natural deposits or a disinfection byproduct.
Aesthetic vs. health numbers
Hardness, TDS, and pH often appear in a separate aesthetic table. They affect taste, spotting, and scale, not safety. For example, Surprise's 2025 report lists hardness under its unregulated table, with an average of 6.2 gpg.
Lead is a home issue too
A utility's lead results can't speak for your own pipes and fixtures. If your home was built before 1986, consider a certified lab test.
- Home water test kit: [AFFILIATE LINK: Amazon-water-test-kit]