Per-and Polyfluoroalkyl Substances (PFAS) Detections in Private Well Water
Per-and polyfluoroalkyl substances (PFAS) are a group of over 9,000 manmade chemicals with useful properties such as repelling water and oil, preventing staining and sticking, and increasing heat resistance. PFAS are used on and in many consumer and industrial products such as non-stick cookware, fabric coatings, food packaging and firefighting foams. The most studied PFAS are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which have already been phased out of production in the United States. However, several other PFAS of concern –perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and perfluoroheptanoic acid (PFHpA)– have not been phased out.
PFAS can migrate through soil and affect groundwater. PFAS are very persistent and can remain in groundwater for long periods of time. The following information is meant for individuals whose private wells have been tested for PFAS.
PFAS Drinking Water Standards and Guidelines
The US Environmental Protection Agency (EPA) has not established a federal enforceable standard (Maximum Contaminant Level (MCL)) for any PFAS but did set a lifetime Health Advisory in 2016 of 70 parts per trillion (ppt) for the sum of two PFAS: PFOS and PFOA. The CT Department of Public Health (DPH) also established its own drinking water Action Level (AL) in 2016 for PFAS of 70 ppt for the sum of five PFAS: PFOS, PFOA, PFNA, PFHxS, and PFHpA. PFAS detections below the Action Level may also warrant investigation to help minimize exposure.
Understanding PFAS Test Results and the CT Action Level
Exposure to PFAS concentrations in excess of the CT DPH Action Level of 70 ppt may increase your risk of developing a variety of health effects. Intake above the AL does not necessarily mean that health problems will happen. However, because these chemicals are known to accumulate in the body, continued consumption of drinking water with PFAS concentrations above the AL may lead to higher PFAS levels in your body.
If your well water is above the AL: consider installing a treatment system and drinking alternative water sources until treatment is in place. Due to the concern about developmental effects, it is especially important that the untreated well water not be used to prepare baby formula, and children and women who are pregnant and/or lactating should consider drinking alternative water sources.
Bathing and Showering: According to the Agency for Toxic Substances and Disease Registry, studies show that only a small amount of PFAS can get into your body through your skin. Therefore, bathing, showering, swimming, and washing dishes in water containing PFAS are not significant sources of exposure. If you have questions about bathing and showering, contact DPH’s Environmental and Occupational Health Assessment Program.
Who Should I Inform of My Result?
Any PFAS detections should be reported to your local health department. They can help determine if your results should be referred to Connecticut Department of Energy & Environmental Protection (DEEP) or DPH for further evaluation. If your well test was organized by your local health department or a state agency, they will be made aware of your result.
What Kind of Treatment Should I Install?
If the level of PFAS in your private well water exceeds the DPH Action Level of 70 ppt for the sum of the five PFAS listed above, you may consider installation of a treatment system to address the problem. There are two treatment types generally considered effective at reducing PFAS in residential private well water: granular activated carbon (GAC) and reverse osmosis (RO). GAC is more appropriate when you need to treat all the water in your home (whole house filter). RO is most practically and commonly used to treat water at a single tap, like your kitchen faucet.
There are treatment devices certified by a third party organization for reducing PFAS in residential drinking water. To find products certified for reducing PFAS, please refer to the National Sanitation Foundation (NSF) International certification listings on their website (NSF Protocol P473 Drinking Water Treatment Units - PFOA & PFOS) or call NSF International’s consumer information specialist at 1-800-673-8010.
Should I Retest My Water?
If PFAS are detected in your private well water above or near the CT Action Level, we recommend that you retest your water to determine whether levels have changed. If you have installed a treatment device to address PFAS, we recommend that you test your treated water to verify that the treatment device is effectively reducing PFAS levels in your water. Please refer to the EPA Approved UCMR3 Labs Registered in CT for Testing Per- and Polyfluoroalkyl Substances in Drinking Water for a list of labs that test for PFAS.
For More Information:
Questions on PFAS Sources:
DEEP Remediation Division: 860-424-3705
Questions on drinking from Private Wells and treatment options:
DPH Private Well Program: 860-509-8401, Email: DPH.PrivateWellProgram@ct.gov
Questions about PFAS Health Effects:
DPH Environmental & Occupational Health Assessment Program: (860) 509-7740,