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 drinking water for PFAS? 

PFAS testing is currently not generally recommended for private well owners, because of the complexity of proper sample collection, cost, and the limited number of labs approved for testing for PFAS. (For general recommendations on what to test for and how often, please refer to the Connecticut DPH's website:  If, however, if your well is located near a suspected PFAS source, you may wish to test your drinking water.  

How can I find a laboratory to test my water?

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.  

What analysis method should I use? 

DEEP recommends using EPA Method 533 for PFAS drinking water analysis. This will insure that all compounds with an established Drinking Water Action Level (DWAL) are evaluated.  EPA Method 537.1 is also acceptable for drinking water PFAS analysis, however PFBA, a PFAS for which CT DPH has established a DWAL, is not included in the method. See below for more information on DWALs.

What does testing entail? 

The laboratory will send you sampling information and a kit for sampling. The kit will include the container for collecting a drinking water sample.  You may also be provided with a container of PFAS-water and a second empty container to collect a "field blank sample."  (The field blank is a sample of PFAS-free water that is prepared by you in a manner similar to your drinking water sample.  It is used to evaluate whether PFAS may have been accidentally introduced during the sample collection process.)  The laboratory will provide very specific instructions for collecting potable water samples and preparing the field blank sample.  It is very important to carefully follow the laboratory instructions or you may accidentally introduce PFAS into your sample. 

How much does testing cost? 

The cost to analyze a drinking water sample varies by lab but is typically $250 – $450 per sample. Ask your laboratory whether the analytical cost includes analysis of the 'field blank' sample.  Often, the drinking water sample and the field blank sample will be billed as separate analyses. 

How long does it take to get my results? 

Once you have submitted your sample to the lab, results will typically be reported to you within 2-3 weeks.  Reporting times can vary, however, so check with your laboratory when submitting your sample. 

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 December 20, 2023.