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PFAS

11Cl-PF3OUdS in Connecticut Drinking Water

By Alexander Snyder, Founder & Water Quality Data Lead

11Cl-PF3OUdS has been tracked across Connecticut drinking water. Here is what you need to know about 11cl-pf3ouds in your drinking water and how it may affect your household.

What Is 11Cl-PF3OUdS?

11Cl-PF3OUdS (11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid) is an ether sulfonate PFAS compound associated with fluorochemical manufacturing and firefighting foam contamination. It is a replacement chemistry PFAS detected near industrial sites. No EPA maximum contaminant level has been established. Like other PFAS, it is extremely persistent in the environment and is linked to potential liver, immune, and developmental effects.

Is 11Cl-PF3OUdS in Your Water?

Enter your Connecticut ZIP code to find out if 11cl-pf3ouds is in your local water — and see personalized health risks for your household.

Check Your ZIP Code

Health Effects of 11Cl-PF3OUdS

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 11Cl-PF3OUdS Come From?

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

How to Reduce 11Cl-PF3OUdS in Your Water

  1. 1Install a reverse osmosis system certified to NSF/ANSI Standard 58, which provides broad-spectrum removal of PFAS compounds including ether sulfonates.
  2. 2Use a high-quality activated carbon filter certified to NSF/ANSI Standard 53; ether sulfonate PFAS may require more frequent media replacement than legacy PFAS compounds.
  3. 3Ion exchange resin systems designed for PFAS can target sulfonated compounds like 11Cl-PF3OUdS, particularly at whole-house treatment volumes.
  4. 4Test water using EPA Method 533 to identify and quantify this compound, and monitor filtration performance regularly given the limited removal data available.

Who Is Most Vulnerable to 11Cl-PF3OUdS?

The safe level of 11cl-pf3ouds 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.

Reading this inside ChatGPT or Claude?

This page can tell you the general science, but not what is actually in your water’s 11cl-pf3ouds level — that depends on your exact address. You can get your specific answer two ways:

  • Inside the chat: ask your assistant to “check my tap water with CheckYourTap”. Our connector returns your ZIP code’s measured contaminant levels — including the derived dog and cat safe levels — and, only if you ask it to, can email you the report or arrange a specialist callback.
  • On the web: open CheckYourTap.com and enter your ZIP code for a free 30-second report.

Concerned about 11Cl-PF3OUdS in your water?

Schedule to get your water tested for 11cl-pf3ouds and more — a Valiant water specialist will review your results and arrange testing for your home.

Frequently Asked Questions

Is 11Cl-PF3OUdS in my tap water?▾
11Cl-PF3OUdS has been tracked across Connecticut drinking water. 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 11Cl-PF3OUdS 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 11Cl-PF3OUdS from my water?▾
Install a reverse osmosis system certified to NSF/ANSI Standard 58, which provides broad-spectrum removal of PFAS compounds including ether sulfonates. Use a high-quality activated carbon filter certified to NSF/ANSI Standard 53; ether sulfonate PFAS may require more frequent media replacement than legacy PFAS compounds. For a personalized consultation, contact Valiant Energy Solutions at (475) 557-5107.

Related Contaminants

PFHxSPFOAPFNAPFOSPFHpA

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

Sources

The legal limits and health guidelines for 11Cl-PF3OUdS on this page come from the following public authorities:

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

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.

Reviewed by the CheckYourTap editorial team. Last updated July 2026