Is Nashua, NH Tap Water Safe to Drink?
Yes, Nashua tap water is safe to drink. Hardness is low at 28 PPM, and no contaminants exceed health guidelines. Most homes here don't need treatment.
Hardness Scale: Where Nashua Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Nashua Compares
Nashua's water is 80% softer than the national average of 138 PPM - ranking in the bottom 85% for hardness nationwide. Most homes here do not need a softener. Within New Hampshire, Nashua has the 3rd hardest water out of 6 cities - 17% above the state average of 24 PPM. Among cities (50k-100k), Nashua ranks #231 of 258 for hardness.
What Nashua's Water Means for Your Home
Hardness: 28 PPM - Low Concern
Nashua's water is slightly hard at 28 PPM. Most households won't notice any issues at this level. Scale buildup is minimal, and a water softener would be overkill. Nashua is softer than 85% of US cities. If you're thinking about water treatment, contaminant filtration is where to focus your money, not softening.
Contaminants & Safety
Beyond hardness, Nashua's water is within EPA guidelines for regulated contaminants. Chlorine is relatively low at 0.8 mg/L. 4 contaminants exceed EWG's stricter health guidelines, though all are within legal limits.. Want the full picture? Request your utility's annual Consumer Confidence Report for neighborhood-level data.
What's in the Treatment Process
Nashua's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: HAA5 at 17.8 ppb (null% of the legal limit, but 296x 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 0.0488 ppb, which is 2.4x 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.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 28 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 35 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 0 ppt | — | No total limit | ✓ ND |
| ↳ 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 | Not reported | 5 mg/L | 10 mg/L | N/A |
Good news for Nashua 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 Nashua
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 Pennichuck Water Works's annual Consumer Confidence Report for official city-level data.
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About Nashua's Water Supply
Water Utility: Pennichuck Water Works
Water Source: Pennichuck Brook & wells (Surface Water)
Population Served: 89,073
Hardness: 28 PPM (1.6 grains per gallon)
Nashua's drinking water comes from surface sources — Pennichuck Brook & wells. 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 89,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request Pennichuck 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 Pennichuck Water Works in Nashua, NH, including ZIP codes:
01430, 01431, 01450, 01462, 01463, 01464, 01469, 01470, 01471, 01472, 01474, 01827, 03031, 03033, 03048, 03049, 03051, 03052, 03055, 03060, 03061, 03062, 03063, 03064, 03071, 03084, 03086
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Nashua to Other New Hampshire Cities
Frequently Asked Questions About Nashua Water
Is Nashua tap water safe to drink?
Where does Nashua's water come from?
Do I need a water softener in Nashua?
What are disinfection byproducts in Nashua's water?
Is chromium-6 in Nashua's water?
Can I drink Nashua tap water straight from the faucet?
What water filter is best for Nashua?
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.