PFAS Information for Private Well Owners

The Connecticut Department of Public Health (CT DPH) is responsible for drinking water, including private wells, in Connecticut. If natural contamination is discovered within a private well, the CT DPH Private Well Program will work with the homeowner to resolve the issue. 

However, when contamination is present in drinking water as a result of human activity, the DEEP Remediation Division's Potable Water Program can assist with investigation of the contamination source, evaluating water testing results, and providing guidance on available water treatment alternatives.  Because all PFAS are human-made, PFAS contamination of a private well falls within the scope of the Potable Well Program.

The following information is provided as guidance for private well owners who are considering testing their drinking water for PFAS. 

Frequently Asked Questions About Private Well PFAS Testing

Should I test my well for PFAS? 

If your well is located near a suspected or probable source of PFAS, you might consider testing. PFAS testing is currently not broadly recommended for all private well users, because of the complexity of proper sample collection, cost, and the limited number of labs approved for testing for PFAS. 

Connecticut DPH does however encourage private well owners to test their drinking water for other common naturally occurring contaminants and general potability (suitability for drinking).  For general recommendations on what to test for and how often, please refer to the Connecticut DPH's website:

How can I get my well tested? (I have reason to suspect PFAS contamination in my well.)

If you have reason to suspect that you may have PFAS in your drinking water, you can contract a certified lab to test your water.  DPH certifies labs for this purpose; the current list can be found on the Connecticut DPH’s Environmental Laboratory Certification Program’s website.  The cost to analyze a drinking water sample varies by lab but is typically $250 – $450 per sample.  Be sure to request analysis using either EPA Method 533 or 537.1. If the lab asks, DEEP recommends that you analyze for PFOS, PFNA, PFOA and PFHxS at a minimum, however we strongly encourage homeowners who are testing to request analysis for all PFAS on the method list. 

The laboratory will send you sampling information and a container. The laboratory will provide very specific instructions for collecting potable water samples; be sure to adhere to these instructions or you may accidentally introduce PFAS into your sample.  Once you have submitted your sample to the lab, results will typically arrive within 2-3 weeks.  

What do my well sampling results mean? 

The Connecticut Department of Public Health (CT DPH) establishes drinking water Action Levels (DWALs) that are protective of public health and also feasible based upon analytical detection and treatment technology. As of June 2023, CT DPH has established drinking water Action Levels for ten PFAS. In order to understand your well sampling results, for each chemical, compare the concentration reported in your well to the Action Level in the table below.  

If your well results contain one or more of these PFAS at concentrations above the Action Level, please notify both the DEEP and the Department of Public Health (DPH) by sending an email, with a copy of your results attached to and  If PFAS are present at levels below the Action Level, you and your family can continue to safely drink your well water. 

Chemical Contaminant 
CT Action Level
(ng/L, ppt)
EPA Method
 EPA Method
Date of DWAL
6:2 chloropolyfluoroether sulfonic acid1
 6:2 Cl-PFESA; F-53B major 2 X X 2023
8:2 chloropolyfluoroether sulfonic acid1  8:2 Cl-PFESA; F-53B minor 5 X X 2023
Hexafluoropropylene oxide-dimer acid  HFPO-DA; GenX 19 X X 2023
Perfluorobutane sulfonic acid  PFBS 760 X X 2023
Perfluorobutanoic acid  PFBA 1800 X 2023
Perfluorohexane sulfonic acid  PFHxS 49 X X 2022
Perfluorohexanoic acid PFHxA 240 X X 2023
Perfluorooctane sulfonic acid PFOS 10 X X 2022
Perfluorooctanoic acid PFOA 16 X X 2022 
Perfluorononanoic acid PFNA 12 X X 2022 

EPA Methods 533 and 537.1 refer to 6:2 Cl-PFESA as 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) and 8:2 Cl-PFESA as 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS).

If you have questions about other PFAS detected in your water that do not have drinking water Action Levels, please contact DPH’s Environmental Health Program

What should I do if my well contains PFAS levels above DPH’s drinking water Action Levels? 

If your well results contain one or more of these PFAS at concentrations above the Action Level, please notify both the DEEP and the Department of Public Health (DPH) by sending an email, with a copy of your results attached to and  (If well contamination exceeds the value shown on the Action Level list above, DEEP is authorized under CT General Statutes Section 22a-471 to take further action in addressing groundwater contamination at the site.)

Until treatment can be installed, it is recommended that you use an alternative water source such as bottled water for cooking and drinking. (PFAS cannot be removed by boiling water.)  Well water can continue to be safely used for bathing purposes. 

It is recommended that you contact your veterinarian to determine whether you should offer bottled water to pets in your home. Please refer to the DPH PFAS General Information webpage for more details and additional guidance regarding pets and agricultural water uses.

What treatment options are available for removing PFAS from private drinking water wells?

Effective treatment options for reducing PFAS in well water include the use of primarily two treatment technologies: granular activated carbon (GAC) and point of use reverse osmosis (RO). Treatment effectiveness depends on having the right size system and proper maintenance. For specific devices, it is best to check with the manufacturer of your treatment device. 

To find products certified to reduce PFOA and PFOS by the National Sanitation Foundation (NSF) please refer to: NSF Protocol P473 Drinking Water Treatment – PFOA & PFOS. There are currently no treatment devices certified to reduce PFASs other than PFOA and PFOS. 

For additional information on water treatment, please consult with DPH’s Private Well Program or a water treatment professional for options to remove PFAS.

Where can I find more information? 

The following webpages contain additional information about PFAS in drinking water:

Who can I contact if I still have questions? 

If you have confirmed PFAS contamination in your private well, questions regarding treatment options and investigation can be directed to DEEP by emailing (Under normal circumstances, you will receive a reply within 1-2 business days.)

For health related questions, contact your local health department or the DPH Private Well Program (860-509-8401 or

Related Webpages:


Content last updated July 13, 2023.