Tap WaterIndex

← Michigan

Tap water quality report

Ann Arbor

EPA monitoring tested this supplier for 31 contaminants and detected 4. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

31
contaminants tested
4
detected
123,851
people served
68
health-based violations
Michigan rankingsLead in MichiganPFAS in Michigan
Water source
Surface water
Ownership
Local government
Counties served
Washtenaw

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

68
health-based violations
113
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2008-01-01 → 2008-01-31
TT Health-based Resolved 2008-01-01 → 2008-01-31
TT Health-based Resolved 2008-01-01 → 2008-01-31
TT Health-based Resolved 2008-01-01 → 2008-01-31
TT Health-based Resolved 2006-07-01 → 2006-07-31
TT Health-based Resolved 2006-07-01 → 2006-07-31
TT Health-based Resolved 2006-07-01 → 2006-07-31
TT Health-based Resolved 2006-07-01 → 2006-07-31
TT Health-based Resolved 2006-06-01 → 2006-06-30
TT Health-based Resolved 2006-06-01 → 2006-06-30

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
Pfpea 0.0047 µg/L 3/4 2023
Pfba 0.0061 µg/L 1/4 2023
Pfhxa 0.0035 µg/L 1/4 2023

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Lead
0.0023 mg/L 15%
of the EPA limit 0.0150 mg/L
 14/14 LCR 2023
27 contaminants tested, none detected
11Cl-PF3OUdS4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaHfpo-DaNetfosaaNfdhaNmefosaaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpesPftaPftrdaPfunaLithium

Utility contact

Contact
MACIEJEWSKI, MOLLY
Phone
734-794-6000
Email
[email protected]

Frequently asked questions about Ann Arbor

Is Ann Arbor tap water safe to drink?

EPA monitoring detected 4 contaminants in Ann Arbor's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Ann Arbor's water?

EPA monitoring detected Lead, Pfpea, Pfba, Pfhxa. The full list with the level and data source for each is above.

How many people does Ann Arbor serve?

Ann Arbor reports serving 123,851 people in Michigan, per its EPA record.

Has Ann Arbor had any water quality violations?

The EPA has 113 violations on file for Ann Arbor, of which 68 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.