Ann Arbor Water Quality Summary
Ann Arbor supplies drinking water to about 241,868 people in Ann Arbor, Michigan, and draws from surface water (rivers, lakes, or reservoirs), which requires fuller treatment for runoff, sediment, and microbial risk. On the IsWaterSafe scale it earns a good Water Safety Score of 89 out of 100 (Grade B), a composite of its EPA SDWIS violation and contaminant record.
This system has no health-based violations on record, but EPA logs 2 monitoring violations — failures to test or report water quality on schedule rather than confirmed contamination. 3 enforcement actions are recorded against the system.
No individual contaminant detections are reported for Ann Arbor in the current EPA SDWIS extract; the score reflects its violation and enforcement record alone.
The most recent documented episode is a monitoring violation, beginning November 2016 and marked resolved November 2016.
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Detected Contaminants
No contaminant data available.
Violation History
Frequently Asked Questions
Ann Arbor has a Water Safety Score of B (89/100). The system serves 241,868 people and has 0 health violations on record. Check the contaminant table above for specific detected substances.
Ann Arbor has 0 contaminant exceedances above EPA health guidelines. See the full contaminant detection table above for all tested substances and their levels relative to legal limits and health guidelines.
The Water Safety Score (0-100, grades A through F) is based on contaminant levels relative to legal limits, health guideline exceedances, violation history, and enforcement actions. Higher scores indicate fewer concerns.
If your water system has violations, request the Consumer Confidence Report from your utility, consider getting an independent water test from a certified lab, and look into certified water filters for specific contaminants of concern. For lead, run cold water for 30 seconds before drinking.
Water quality data sourced from EPA's Safe Drinking Water Information System (SDWIS). Safety scores are calculated based on contaminant levels, violations, and enforcement history. This is not a substitute for your utility's official Consumer Confidence Report.
Source: EPA Ground Water and Drinking Water, 2026.