Is Ann Arbor, MI Tap Water Safe to Drink?
Yes, Ann Arbor tap water is safe to drink. No contaminants exceed health guidelines. However, Ann Arbor has hard water at 163 PPM, which will cause scale buildup in plumbing and appliances over time. A softener or conditioner is worth considering.
Hardness Scale: Where Ann Arbor Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Ann Arbor Compares
Ann Arbor's water is 18% harder than the national average of 138 PPM. It ranks #420 out of 1000 cities in our database (harder than 58% of US cities we track). Within Michigan, it ranks #13 of 26 cities (9% below the state average of 179 PPM). Among large cities (200k-500k), Ann Arbor ranks #63 of 165 for hardness. At this hardness level, water heaters run an estimated 30% less efficiently due to scale insulation, and major water-using appliances typically last 2 years less than the national average lifespan.
What Ann Arbor's Water Means for Your Home
Hardness: 163 PPM - Treatment Recommended
Ann Arbor's water is hard at 163 PPM (9.5 GPG). That's enough to notice every day: gradual scale on fixtures, spots on dishes, soap that doesn't lather the way it should. That's 9% softer than the Michigan average. Homeowners who install a water softener or salt-free conditioner notice the difference fast: better lathering, cleaner dishes, and appliances that last longer. That adds up. Hard water at 163 PPM increases household costs through scale-coated water heaters that use more energy, extra soap and detergent, and appliances that wear out faster. Most Ann Arbor homeowners don't realize it until the plumber shows up.
Contaminants & Safety
Disinfection byproducts are the notable finding here. Ann Arbor's water has TTHMs at 4.49 ppb and HAA5 at 6.6 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
Ann Arbor's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 4.49 ppb (6% of the legal limit, but 30x the EWG guideline) and HAA5 at 6.6 ppb (11% of the legal limit, but 66x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts.
Chromium-6 was detected at 0.226 ppb, which is 11x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
How Hard Water Affects Your Home
At 163 PPM, untreated hard water has measurable effects on household costs and appliance life:
- Water heater inefficiency: Scale insulation forces the heater to work harder (DOE estimates up to 22% more energy for heavily scaled units)
- Soap and detergent: Hard water reduces lathering, requiring significantly more product
- Appliance replacement: Water heaters, dishwashers, and washing machines fail 2-4 years earlier due to scale buildup
- Plumbing maintenance: Scale buildup in pipes reduces flow and requires more frequent service
Note: Impact varies by household size, water usage, and local energy costs. A home water test provides the most accurate assessment for your specific situation.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 163 PPM | < 60 PPM | No federal limit | ⚠ Hard |
| Total Dissolved Solids | 195 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 13.2 ppt | — | No total limit | Detected |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 2.3 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 0.8 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 0.458 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Our Top Picks for Ann Arbor (163 PPM)
Hard water at 163 PPM causes scale buildup, increased energy use, and premature appliance failure. A softener protects your plumbing and appliances.
How to Test Your Water in Ann Arbor
With 163 PPM hardness, a quick test strip confirms whether your specific tap matches Ann Arbor's average before you invest in a softener. Hardness can vary within the same system.
Free option: Request Ann Arbor Water's annual Consumer Confidence Report for official city-level data.
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About Ann Arbor's Water Supply
Water Utility: Ann Arbor Water
Water Source: Huron River (Surface Water)
Population Served: 241,868
Hardness: 163 PPM (9.5 grains per gallon)
Ann Arbor's drinking water comes from surface sources — Huron River. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. Despite the treatment process, mineral hardness from the watershed carries through. The system serves 242,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request Ann Arbor Water's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by Ann Arbor Water in Ann Arbor, MI, including ZIP codes:
48103, 48104, 48105, 48106, 48107, 48108, 48109, 48113, 48115, 48118, 48130, 48139, 48158, 48189, 49201, 49202, 49203, 49204, 49220, 49230, 49233, 49234, 49236, 49240, 49241, 49242, 49246, 49249, 49250, 49253, 49254, 49257, 49261, 49262, 49263, 49265, 49266, 49271, 49281, 49282, 49287
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Water Softener Sizing for Ann Arbor
At 163 PPM (9.5 GPG), here is how to size a softener for your Ann Arbor home. Multiply hardness in GPG (9.5) by daily water usage (roughly 50 gallons per person). A family of four uses about 200 gallons/day: 9.5 GPG × 200 gal = 1900 grains/day. Over a 7-day regeneration cycle, that is 13,300 grains - a 32,000-grain softener is the right fit for most Ann Arbor households.
Compare Ann Arbor to Other Michigan Cities
Frequently Asked Questions About Ann Arbor Water
Is Ann Arbor tap water safe to drink?
Where does Ann Arbor's water come from?
Do I need a water softener in Ann Arbor?
Does Ann Arbor water damage tankless water heaters?
How much does hard water cost a Ann Arbor household per year?
What is the hardness of Ann Arbor water in grains per gallon?
What size water softener do I need for Ann Arbor?
Salt-based softener or salt-free conditioner for Ann Arbor?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.
What Ann Arbor Homeowners Actually Buy
Common purchases for homes with 163 PPM water.
Affiliate disclosure: we may earn a commission. Selection based on Ann Arbor's water data.