Water Quality in Norwalk, CT 06850
By Alexander Snyder, Founder & Water Quality Data LeadLast reviewed July 2026
Water testing in Norwalk (06850) has identified 80 contaminants — nearly 3x the state average. This is among the highest detection counts in Connecticut, which means residents here face a wider range of potential exposures than most of the state. For households with infants, elderly members, or pets, the risks may be compounded because many of these contaminants have stricter health guidelines for vulnerable populations.
Is Norwalk, CT tap water safe to drink?
Whether Norwalk tap water is safe depends on your household. 80 contaminants have been detected in ZIP 06850. Federal legal limits and stricter health-based guidelines are not the same thing, and some contaminants matter more for vulnerable groups like infants, pregnancy, and older adults. Enter your ZIP above for a personalized risk assessment.
Get Your Personalized Report
See how 80 contaminants affect your specific household members — babies, children, pregnant women, elderly, dogs, and cats.
Check 06850 Water NowKey Facts About Norwalk Water
80
substances found in local water testing
11
household member types including pets
What Norwalk Residents Should Know
Norwalk's water supply has one of the highest contaminant detection counts in Connecticut. Health guidelines from the EWG and California OEHHA are often stricter than federal legal limits — a contaminant can be "legal" but still exceed recommended health levels. This is especially important for babies under one year, whose developing organs are more susceptible to even low-level chemical exposure.
Contaminants Detected in Norwalk, CT 06850 Water
Detected in public water testing for ZIP 06850, ranked by how often samples were above the EPA limit. Enforceable health limits are shown in red; secondary (aesthetic) standards like manganese are advisory, not legal limits.
| Contaminant | Detected in | Samples | Exceeds EPA limit | EPA limit |
|---|---|---|---|---|
| PFOANO_SAFE_LEVEL | 43.5% | 23 | 43.5% | 4 ppt |
| PFOSNO_SAFE_LEVEL | 20% | 20 | 20% | 4 ppt |
| ManganeseOTHER | 100% | 20 | 20% (aesthetic) | 50 ppb (secondary) |
| LeadNO_SAFE_LEVEL | 95.2% | 166 | 8.4% | 0.015 mg/L |
| ArsenicOTHER | 100% | 1 | No | 0.01 mg/L |
| DEHP (Phthalate)OTHER | 100% | 1 | No | 0.006 mg/L |
| Gross BetaOTHER | 100% | 4 | No | 4 mrem/year |
| chromium-6ZERO_TOLERANCE | 81.5% | 27 | No | — |
Source: EPA SDWIS / UCMR public water testing. Detection and exceedance rates reflect samples in this area; enter your ZIP above for a report personalized to your household. Most recent sample in this area: 2025.
Want to know exactly what’s in your Norwalk water?
80 contaminants have been detected in ZIP 06850. Schedule to get your water tested with a Valiant water specialist — they’ll review your results and arrange testing for your home.
Have a dog or cat in Norwalk?
5 of the contaminants detected in 06850 have pet-specific concerns — dogs and cats drink far more water per pound of body weight than people, and some are more sensitive. See what they mean for your pet:
Environmental Sites Near Norwalk, CT 06850
Documented sites in or near this ZIP from EPA and CT DEEP records. These are most relevant for private-well owners as potential groundwater concerns — public water is treated and tested separately. Their presence near a ZIP does not by itself mean your drinking water is affected, but it’s a reason for well owners to test.
Compiled from EPA (SEMS/TRI/ECHO) and CT DEEP records; many are undated historical site inventories. Most recent dated event in this area: 2026-12-31.
Who in Norwalk Is Most Affected
Some contaminants matter more for certain people, because the safe levels for them are stricter than for a healthy adult. Based on the contaminants of concern detected in ZIP 06850 — those found above a limit, or with no safe level (some may be within legal limits but still matter here):
For infants: PFOA, Manganese, Lead, Arsenic, and Gross Beta.
PFOA 'forever chemicals' linked to developmental and immune effects; can transfer through the placenta and breast milk; Manganese excess manganese is a recognized neurodevelopmental concern for infants.
For pregnancy: PFOA, Lead, Arsenic, and Gross Beta.
PFOA 'forever chemicals' linked to developmental and immune effects; can transfer through the placenta and breast milk; Lead harms developing brains — there is no safe level for children, and it crosses the placenta.
For young children: Lead.
Lead harms developing brains — there is no safe level for children, and it crosses the placenta.
Tell us who lives in your home above for a report personalized to the people in it.
Frequently Asked Questions
Is the tap water safe to drink in Norwalk, CT?▾
What contaminants are in 06850 water?▾
Is Norwalk water safe for infants, pregnancy, and children?▾
Is Norwalk, CT tap water safe for dogs and cats?▾
Is CheckYourTap free?▾
Does Norwalk have well water data?▾
Other ZIP Codes in Norwalk
Related Reading
About This Report
Water quality data for Norwalk, CT 06850 is compiled from public records filed with the U.S. Environmental Protection Agency (EPA SDWIS), the U.S. Geological Survey (USGS NWIS), and the Connecticut Department of Public Health. Health guidelines reference the strictest available standards from the EWG, California OEHHA, and WHO. Risk assessments are personalized for 11 household member types. CheckYourTap is a service of Valiant Energy Solutions, a Connecticut company established in 1930.
This report is general information, not medical advice or a substitute for certified laboratory testing. Talk to your pediatrician or physician about specific health concerns.
By Alexander Snyder, Founder & Water Quality Data Lead. Last updated July 2026