Water Quality Report · Updated May 12, 2026
ANN ARBOR
ANN ARBOR delivers tap water graded D (61/100) by TapWaterSafety.org. The utility serves approximately 123,851 residents in ANN ARBOR, Michigan using surface water. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Bromate significantly above health guideline. For questions, the utility can be reached at 734-794-6000.
Is ANN ARBOR tap water safe to drink?
ANN ARBOR delivers tap water that earns a grade of D (61/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including pfas contamination.
The utility serves 123,851 residents in ANN ARBOR, drawing from surface water.
Public testing data identifies 11 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Haloacetic acids (HAA5), Bromate, Perfluorodecanoic acid (PFDA), Total trihalomethanes (TTHMs), Perfluorododecanoic acid (PFDoA), Chromium (hexavalent), Perfluoropentane sulfonic acid (PFPeS), Nitrate, Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for ANN ARBOR residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for ANN ARBOR.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 4.55 ppb, 76x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 6.6 ppb, 66x above the EWG health guideline of 0.1 ppb.
Bromate significantly above health guideline
Moderate concernBromate detected at 3.9 ppb, 39x above the EWG health guideline of 0.1 ppb.
Contact ANN ARBOR
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for ANN ARBOR
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 61/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
4.55 ppb | 0.06 | — | — | — | — | — | 76× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
6.6 ppb | 0.1 | 60.0 | 60 | — | — | — | 66× over |
| Bromate Disinfection byproduct |
3.9 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 39× over |
| Perfluorodecanoic acid (PFDA) PFAS |
0.231 ppt | 0.006 | — | — | — | — | — | 39× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
4.49 ppb | 0.15 | 80.0 | 100 | — | — | — | 30× over |
| Perfluorododecanoic acid (PFDoA) PFAS |
0.892 ppt | 0.06 | — | — | — | — | — | 15× over |
| Chromium (hexavalent) Heavy metal |
0.226 ppb | 0.02 | — | — | — | — | — | 11× over |
| Perfluoropentane sulfonic acid (PFPeS) PFAS |
7.37 ppt | 1.0 | — | — | — | — | — | 7.4× over |
| Nitrate Inorganic |
0.458 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 3.3× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.101 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 1.1× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.321 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 1.1× over |
| Chlorate Disinfection byproduct |
192.1 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
5.39 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
0.416 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.921 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
4.61 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
2.79 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
0.6 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
0.339 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.486 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.14 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.0225 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.669 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Nitrite Inorganic |
0.0323 ppm | — | 1.0 | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
ANN ARBOR service area
This water system serves 1 community in Washtenaw County, Michigan. Click any city for its dedicated tap water quality page.
Find the right filter for ANN ARBOR water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.