Is my tap water safe to drink in Connecticut?

It depends on your ZIP code and who lives in your home. CheckYourTap analyzes 120+ contaminants in your local water supply and shows which ones exceed health guidelines — not just legal limits. Many contaminants are legal but still pose health risks, especially for babies, pregnant women, elderly, and pets.

What contaminants are in Connecticut tap water?

Connecticut tap water commonly contains disinfection byproducts (haloacetic acids, trihalomethanes), lead from aging pipes, PFAS (forever chemicals), nitrates, arsenic, and radionuclides like radium. The specific contaminants and levels vary by water system — enter your ZIP code to see your local results.

How does CheckYourTap differ from EWG or other water quality databases?

CheckYourTap is the only water quality report personalized for your household composition. Tell us who lives in your home — babies, children, pregnant women, elderly, dogs, or cats — and we calculate adjusted safe levels for each person. A contaminant safe for adults may exceed guidelines for infants by 8x or more.

Is CheckYourTap free?

Yes, CheckYourTap is completely free. Enter your Connecticut ZIP code and household members to get a personalized water quality report with health risk assessments for 120+ contaminants.

Does CheckYourTap cover well water in Connecticut?

Yes. CheckYourTap covers both city water (public water systems) and private well water in Connecticut. Well water reports use USGS groundwater data and include geology-based risk factors for arsenic, uranium, and radon specific to your area.

PFAS

9Cl-PF3ONS in Connecticut Drinking Water

9Cl-PF3ONS has been detected in water systems serving 6,160 ZIP codes nationwide. Here is what you need to know about 9cl-pf3ons in your drinking water and how it may affect your household.

What Is 9Cl-PF3ONS?

9Cl-PF3ONS (9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid) is a chlorinated ether sulfonate PFAS compound found near fluorochemical manufacturing sites and areas impacted by firefighting foam. It is part of the newer generation of PFAS replacement chemicals. No EPA maximum contaminant level has been set. It is extremely persistent in the environment and associated with potential liver and immune system effects.

Is 9Cl-PF3ONS in Your Water?

Enter your Connecticut ZIP code to find out if 9cl-pf3ons is in your local water — and see personalized health risks for your household.

Check Your ZIP Code

Health Effects of 9Cl-PF3ONS

Part of the PFAS (per- and polyfluoroalkyl substances) family of 'forever chemicals.' Linked to cancer, immune system harm, hormone disruption, and developmental effects. Does not break down in the environment or the human body.

Where Does 9Cl-PF3ONS Come From?

Industrial discharge, firefighting foam (AFFF), consumer products, landfill leachate, wastewater treatment plants.

How to Reduce 9Cl-PF3ONS in Your Water

1Install a reverse osmosis system certified to NSF/ANSI Standard 58, which provides effective broad-spectrum removal of PFAS including ether sulfonates.
2Use a high-quality activated carbon filter certified to NSF/ANSI Standard 53 for PFAS reduction, with awareness that newer PFAS chemistries may have varying adsorption characteristics.
3Ion exchange resin systems designed for PFAS can target sulfonated compounds like 9Cl-PF3ONS at whole-house treatment volumes.
4Test water using EPA Method 533 to identify and quantify this compound, and establish a regular monitoring schedule given limited long-term removal data.

Who Is Most Vulnerable to 9Cl-PF3ONS?

The safe level of 9cl-pf3ons varies significantly depending on who is drinking the water. CheckYourTap calculates adjusted safe levels for each member of your household:

Infants (under 1 year)

Toddlers (1-3 years)

Children (4-11 years)

Pregnant women

Elderly (65+)

Adults

Dogs

Cats

A contaminant level that is safe for an adult may exceed guidelines for an infant by 4-8x or more. Check your ZIP code to see personalized results.

Frequently Asked Questions

Is 9Cl-PF3ONS in my tap water?▾

9Cl-PF3ONS has been detected in water systems across 6,160 ZIP codes. Whether it's in your specific water depends on your local water system. Enter your CT ZIP code at CheckYourTap.com for a free, instant report.

What level of 9Cl-PF3ONS is safe?▾

The safe level depends on who is drinking the water. Health guidelines vary by source, but infants, pregnant women, and pets may need much lower levels. CheckYourTap calculates adjusted safe levels for 11 different household member types.

How do I remove 9Cl-PF3ONS from my water?▾

Install a reverse osmosis system certified to NSF/ANSI Standard 58, which provides effective broad-spectrum removal of PFAS including ether sulfonates. Use a high-quality activated carbon filter certified to NSF/ANSI Standard 53 for PFAS reduction, with awareness that newer PFAS chemistries may have varying adsorption characteristics. For a personalized consultation, contact Valiant Energy Solutions at (475) 557-5107.

Related Contaminants

PFHxS PFOA PFNA PFOS PFHpA

Check Water Quality by ZIP Code

Hartford 06103 New Haven 06510 Bridgeport 06604 Stamford 06901 Waterbury 06702 Norwalk 06850 Danbury 06810 Manchester 06040 View all cities →

View all contaminants in Connecticut water

About This Report

This water quality report is compiled from public records filed with the U.S. Environmental Protection Agency, state health departments, and the U.S. Geological Survey. Contaminant levels are evaluated against EPA federal standards and health-based guidelines from leading environmental and public health organizations. CheckYourTap is a service of Valiant Energy Solutions, a Connecticut water quality and energy services company established in 1930.

EPA SDWISUSGS NWISEWG Tap Water DatabaseCA OEHHA Public Health GoalsWHO Drinking Water Guidelines

Last updated March 2026