Is Mount Kisco, NY Tap Water Safe to Drink?
Yes, Mount Kisco tap water is safe to drink. Hardness is low at 45 PPM, and no contaminants exceed health guidelines. Most homes here don't need treatment.
Hardness Scale: Where Mount Kisco Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Mount Kisco Compares
Mount Kisco's water is 67% softer than the national average of 138 PPM - ranking in the bottom 73% for hardness nationwide. Most homes here do not need a softener. Within New York, it ranks #17 of 37 cities (27% below the state average of 62 PPM). Among smaller cities, Mount Kisco ranks #180 of 288 for hardness.
What Mount Kisco's Water Means for Your Home
Hardness: 45 PPM - Low Concern
Mount Kisco's water is slightly hard at 45 PPM. Most households won't notice any issues at this level. Scale buildup is minimal, and a water softener would be overkill. If you're thinking about water treatment, contaminant filtration is where to focus your money, not softening.
Contaminants & Safety
Disinfection byproducts are the notable finding here. Mount Kisco's water has TTHMs at 42.9 ppb and HAA5 at 31 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
Mount Kisco's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 42.9 ppb (54% of the legal limit, but 286x the EWG guideline) and HAA5 at 31 ppb (52% of the legal limit, but 310x 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. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 45 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 75 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 3.1 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 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 | 0.345 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Good news for Mount Kisco residents. Your water quality is generally good. Most homes in this area do not need a water softener. If you have concerns about lead (especially in buildings constructed before 1986) or chlorine taste, a point-of-use filter is the most practical and cost-effective solution.
How to Test Your Water in Mount Kisco
City-wide data is a solid starting point, but your specific tap might differ based on plumbing age, distance from the treatment plant, or seasonal changes.
Free option: Request Westchester Joint Water Works's annual Consumer Confidence Report for official city-level data.
📊 Already Tested Your Water?
City averages miss neighborhood-level variation. Share your results to help your neighbors get better data.
We review every submission before publishing. Your ZIP is shown; your identity is not.
About Mount Kisco's Water Supply
Water Utility: Westchester Joint Water Works
Water Source: Surface water (Surface Water)
Population Served: 11,187
Hardness: 45 PPM (2.6 grains per gallon)
Mount Kisco's drinking water comes from surface sources — Surface water. 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. On the upside, surface sources often deliver softer water than deep aquifers. The system serves 11,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request Westchester Joint Water Works'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 Westchester Joint Water Works in Mount Kisco, NY, including ZIP codes:
10453, 10457, 10458, 10460, 10461, 10462, 10463, 10465, 10466, 10467, 10468, 10469, 10470, 10471, 10472, 10473, 10475, 10549
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Mount Kisco to Other New York Cities
Frequently Asked Questions About Mount Kisco Water
Is Mount Kisco tap water safe to drink?
Where does Mount Kisco's water come from?
Do I need a water softener in Mount Kisco?
What are disinfection byproducts in Mount Kisco's water?
Can I drink Mount Kisco tap water straight from the faucet?
What water filter is best for Mount Kisco?
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.