Is Norwalk, CT Tap Water Safe to Drink?
Norwalk tap water is legally compliant, but one contaminant exceeds health guidelines. Specifically: PFAS above EPA limits (PFOA: 7.73 ppt, PFOS: 6.25 ppt — limit is 4 ppt each). A point-of-use filter is recommended for drinking and cooking water.
Hardness Scale: Where Norwalk Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Norwalk Compares
Norwalk's water is 82% softer than the national average of 138 PPM - ranking in the bottom 87% for hardness nationwide. Most homes here do not need a softener. Within Connecticut, it ranks #7 of 13 cities (19% below the state average of 31 PPM). Among large cities (200k-500k), Norwalk ranks #150 of 165 for hardness.
What Norwalk's Water Means for Your Home
Hardness: 25 PPM - Low Concern
Norwalk's water is slightly hard at 25 PPM. Most households won't notice any issues at this level. Scale buildup is minimal, and a water softener would be overkill. Norwalk is softer than 87% of US cities. If you're thinking about water treatment, contaminant filtration is where to focus your money, not softening.
Contaminants & Safety
Forever chemicals (PFAS) are worth watching here. Norwalk has PFOA at 7.73 ppt and PFOS at 6.25 ppt, exceeding the EPA's 2024 limit of 4 ppt per compound. PFAS are synthetic compounds that accumulate in your body over time. A certified carbon filter or reverse osmosis system with NSF P473 certification is the most effective protection. See the regulatory timeline.
What's in the Treatment Process
Norwalk's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 52.4 ppb (66% of the legal limit, but 349x the EWG guideline) and HAA5 at 31.9 ppb (53% of the legal limit, but 319x 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 0.0506 ppb, which is 2.5x 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) | 25 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 35 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 39.75 ppt | — | No total limit | Detected |
| ↳ PFOA | 7.73 ppt | 0 ppt | 4 ppt (2024) | ⚠ Exceeds |
| ↳ PFOS | 6.25 ppt | 0 ppt | 4 ppt (2024) | ⚠ Exceeds |
| Lead | 1.7 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 1.5 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 0.765 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommended Filter for Norwalk
PFAS exceed EPA limits (PFOA: 7.73 ppt, PFOS: 6.25 ppt — limit: 4 ppt each). A certified filter reduces these contaminants effectively.
Quick Fix for Chlorine: Shower Filter
At 1.5 mg/L chlorine, many Norwalk residents notice dry skin, brittle hair, and that "pool smell" in the shower. A shower filter installs in 5 minutes, no tools needed.
How to Test Your Water in Norwalk
With PFAS at 39.75 ppt in Norwalk's supply, confirming your home's specific levels is especially important. PFAS vary by neighborhood and can concentrate differently depending on your position in the distribution system.
Free option: Request South Norwalk Electric & Water's annual Consumer Confidence Report for official city-level data.
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About Norwalk's Water Supply
Water Utility: South Norwalk Electric & Water
Water Source: Norwalk River & reservoirs (Surface Water)
Population Served: 351,756
Hardness: 25 PPM (1.5 grains per gallon)
Norwalk's drinking water comes from surface sources — Norwalk River & reservoirs. 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 352,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request South Norwalk Electric & 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 South Norwalk Electric & Water in Norwalk, CT, including ZIP codes:
06840, 06850, 06851, 06852, 06853, 06854, 06855, 06856, 06857, 06858, 06860, 06897, 10576
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Norwalk to Other Connecticut Cities
Frequently Asked Questions About Norwalk Water
Is Norwalk tap water safe to drink?
Where does Norwalk's water come from?
Do I need a water softener in Norwalk?
How do I remove PFAS from Norwalk tap water?
What water filter is best for Norwalk?
Is Norwalk water safe for babies and infants?
What are disinfection byproducts in Norwalk's water?
Is chromium-6 in Norwalk's water?
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 Norwalk Homeowners Actually Buy
Prioritized for contaminant reduction for homes with 25 PPM water and PFAS above EPA limits.
Affiliate disclosure: we may earn a commission. Selection based on Norwalk's water data.