Tap Water Quality Report
Tap water quality in ANN ARBOR, Michigan
Tap water in ANN ARBOR, Michigan receives a grade of C (73/100) from TapWaterSafety.org. It's served by ANN ARBOR. 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. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in ANN ARBOR's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving 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.
EPA compliance record
Official U.S. EPA records for ANN ARBOR (system ID MI0000220) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for ANN ARBOR
Filters matched to the specific contaminants in ANN ARBOR's water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in ANN ARBOR's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. 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, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from ANN ARBOR.