A
90

Excellent Water Quality

Ann Arbor, MI 48105

Washtenaw County · Population served: 243,756 · Data updated March 2026

Water Systems Serving This Area

🏔
ANN ARBOR
Surface water · Pop. 241,868
PWSID: MI0000220
🏔
ANN ARBOR TOWNSHIP
Surface water · Pop. 1,338
PWSID: MI0000221
🌊
BARTON HILLS
Groundwater · Pop. 450
PWSID: MI0000430
🌊
SISTERS OF MARY, MOTHER OF EUCHARIST
Groundwater · Pop. 100
PWSID: MI0006074

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
3.0
15 ppb 1 ppb Warning

PFAS / Forever Chemicals

3 detected All below limits
CompoundLevelEPA MCLHealth GuidelineStatus
PFBA6.1 pptNo standard500 pptUnregulated
PFPeA4.7 pptNo standardUnregulated
PFHxA3.5 pptNo standard400 pptUnregulated

Violation History (Last 5 Years)

1Total (5yr)
0Health-Based
0Major

Water Quality Summary

Understanding Your Water in Ann Arbor

Tap water quality in Ann Arbor, Michigan (48105) receives an overall grade of A (Excellent) with a score of 90 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 12 points above the Michigan state average of 78. Compared to the national average (75), this area performs significantly better. The area is served by 4 water systems providing water to approximately 243,756 people, using surface water and groundwater sources. Testing has found elevated levels of Lead that warrant attention. PFAS testing detected 3 compounds, all currently below EPA limits.

Your Score 90/100 A
vs State 12 pts above Michigan avg (78)
vs National 15 pts above national avg (75)

What a Grade A Means

A score of 90/100 means the water supply in Ann Arbor, MI meets or exceeds all EPA standards with minimal issues. Contaminant levels are well within safe limits, and the water system has maintained a strong compliance record. While no water supply is guaranteed perfect at the tap due to household plumbing, this is among the best-scoring areas in the country.

Surface water: sourced from rivers, lakes, or reservoirs
Groundwater: drawn from underground aquifers via wells

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

Based on EPA data, tap water in Ann Arbor, Michigan receives a grade of A (Excellent) with a score of 90/100. This indicates the water meets federal standards and has relatively few concerns. However, individual homes may still have localized issues such as lead from old plumbing.

ZIP code 48105 is served by 4 water systems using surface water, groundwater sources, providing water to approximately 243,756 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead was detected at 3.0 ppb in Ann Arbor, Michigan. While this is below the EPA action level of 15 ppb, it exceeds the health guideline of 1 ppb recommended by health organizations. Consider a certified lead filter, especially if you have young children.

3 PFAS compounds were detected in water serving Ann Arbor, Michigan, but all are currently below EPA limits. While levels are within regulatory standards, some health organizations recommend minimizing any PFAS exposure. Activated carbon or reverse osmosis filters can reduce PFAS levels.

Water systems serving Ann Arbor, Michigan have received 1 violation in the last 5 years. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead, PFAS), residents in Ann Arbor, Michigan should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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