B74/100
Ann Arbor Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 277,712 residents · Michigan
What's In Ann Arbor's Tap Water?
76
Contaminants Tested
0
Exceed EPA Limits
2
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
chlorate | 400.00 µg/L | — | Above Goal |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2016.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
ANN ARBOR
Population Served
241,868
Water Source
Surface Water
System ID
MI0000220
ANN ARBOR TOWNSHIP
Population Served
1,338
Water Source
Purchased Surface Water
System ID
MI0000221
LOCH ALPINE SANITARY AUTHORITY
Population Served
1,506
Water Source
Groundwater
System ID
MI0003940
PITTSFIELD TOWNSHIP
Population Served
24,500
Water Source
Purchased Surface Water
System ID
MI0005360
SCIO TOWNSHIP
Population Served
8,500
Water Source
Purchased Surface Water
System ID
MI0005977
Frequently Asked Questions About Ann Arbor Water
Is Ann Arbor tap water safe to drink?
Ann Arbor, Michigan tap water receives a grade of B (74/100), which is considered good. Out of 76 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 2 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Ann Arbor's water?
Of the 76 contaminants tested in Ann Arbor's water supply, the most notable include Lead (90th percentile), chlorate. No contaminants exceed EPA legal limits. 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Ann Arbor have any water quality violations?
Yes, Ann Arbor has 63 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, RPT, MR. 30 of these are health-based violations, which are the most serious category.
Do I need a water filter in Ann Arbor?
Ann Arbor water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 2 contaminant(s) exceed these stricter goals.
Where does Ann Arbor's tap water come from?
Ann Arbor's drinking water is sourced from surface water and supplied by ANN ARBOR and 4 other water system(s). The system serves approximately 277,712 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Ann Arbor's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Ann Arbor's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Ann Arbor's water compare to other cities in Michigan?
Ann Arbor's water quality score of 74/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Michigan state page to see how all cities in the state compare.
What should I do if I'm concerned about Ann Arbor's water quality?
If you have concerns about Ann Arbor's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (ANN ARBOR) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.