Home Water Treatment for PFAS

Per- and polyfluoroalkyl substances (PFAS) are a broad class of man-made chemicals that have been widely used in industry and consumer products since the 1940s. PFAS can repel oil and water and resist heat. They are therefore useful ingredients in products such as aqueous film firefighting foam, waterproof apparel, stain-resistant materials, nonstick cookware, etc. Due to their widespread use, PFAS have been detected at low concentrations in water, soil, air, as well as in plant and animal products worldwide. Typical concentrations are in the parts per trillion (ppt) or nanograms per liter (ng/L) ranges. However, some communities may have higher PFAS concentrations, especially if they are located near potential sources such as airports and military bases, manufacturing facilities that produce or use PFAS in their processing, unlined landfills, and farms that have been amended with industrially impacted biosolids containing high PFAS levels.

Contaminated drinking water can be a human exposure pathway to PFAS. In April 2024, the United States Environmental Protection Agency (US EPA) finalized drinking water standards for six PFAS in drinking water. The final maximum contaminant levels (MCLs) are shown in Table 1.

How to find out if PFAS is in your drinking water

If your drinking water is supplied by the city or municipality, you can contact the drinking water provider to inquire about PFAS in your water. If you get your water from a private water system, such as a well, spring, or cistern, it is your responsibility to ensure your drinking water is safe. Below are some steps for assessing PFAS in your drinking water:

Step 1: Identify if there are potential PFAS sources nearby

Private water sources that are adjacent to potential PFAS sources mentioned above may be at risk of PFAS contamination.

Step 2: Consider testing your drinking water source

The Pennsylvania Department of Environmental Protection (PA DEP) has state-accredited labs for PFAS testing in potable water that are available by visiting and searching through the PA DEP Accredited Environmental Laboratories Database. Instructions for using the laboratory database can be found online. The list of PFAS testing laboratories as of August 2025 is also published in the PFAS Testing Services and Laboratories Directory fact sheet.

Step 3: Compare your test results with drinking water standards

Recently finalized federal MCLs for the six PFAS (Table 1) can be used as a reference point when reviewing your test results. For help interpreting your results, refer to the PFAS Test Results - What Do the Numbers and Acronyms Mean? fact sheet, the drinking water interpretation tool (DWIT), or contact a local Extension Educator for assistance.

Home water treatment to reduce levels of PFAS in drinking water

If levels of PFAS in your drinking water are a concern, both point-of-entry (POE) and point-of-use (POU) drinking water treatment devices are available. POE water treatment systems devices are installed to treat the water entering the house or building, with the goal of treating water distributed throughout the entire house. POU treatment systems, on the other hand, treat the water only at a specific use location in the house, typically the primary area used for drinking and cooking, such as the kitchen faucet.

Water treatment devices for PFAS may use activated carbon, reverse osmosis, or ion exchange technologies to purify water. Activated carbon systems rely on the carbon media to trap PFAS as water flows through the cartridge. The reverse osmosis (RO) treatment process forces water through an extremely thin membrane barrier under pressure, allowing water to pass through while trapping impurities. Finally, ion exchange utilizes tiny beads, known as resins, that attract and trap PFAS chemicals from water.

Certification of water treatment devices for PFAS removal

National Sanitation Foundation (NSF) International and Water Quality Association (WQA) are independent third-party testing agencies that test and certify POE and POU devices that claim to remove PFOA and PFOS. When purchasing products for PFOA and PFOS removal, look for the following certification information on the vendor website or treatment device packaging:

• NSF/ American National Standards Institute (NSF/ANSI) Standard 53: Drinking Water Treatment Units – Health Effects with the claim of "PFOA Reduction" and "PFOS Reduction"
• NSF/ANSI Standard 58: Reverse Osmosis Drinking Water Treatment Systems with the claim of "PFOA Reduction" and "PFOS Reduction"

Such certifications indicate that the device has undergone rigorous, standardized testing and has been successful in reducing PFOA and PFOS in drinking water. Current NSF/ANSI treatment standards test that a product lowers PFOA and PFOS reduction to a combined concentration of 20 ng/L. While these certifications are currently only available for PFOA and PFOS reduction, certified filters have also been shown to lower the amount of other PFAS that may be found in drinking water. Current certification standards do not indicate if the treatment device will lower concentrations down to the current US EPA MCLs (Table 1).

NSF and WQA-certified POU water treatment devices for PFAS removal

Table 2 below shows various POU water treatment systems by device type, highlighting their treatment technologies, estimated costs, and media replacement schedules. Follow these steps to check if a treatment device you already use or are looking to purchase is NSF certified for PFOA/PFOS:

1. Visit Search for NSF Certified Drinking Water Treatment Units, Water Filters
2. Type the manufacturer to search by the manufacturer tab OR
3. In the "Product Standard" box select "Drinking Water Treatment Units—Health Effects (NSF/ANSI 53)" or "Reverse Osmosis Drinking Water Treatment Systems (NSF/ANSI 58)" for the full list of certified systems

Follow these steps to check if a treatment device is WQA certified for PFOA/PFOS:

1. Visit Find WQA Certified Products
2. Type the manufacturer, brand, or model and click search OR
3. In the "Product Category" box, select the type of treatment you are looking for, e.g. filters or reverse osmosis (RO) or
4. In the "Common Contaminant" box, select the contaminant of interest, e.g. PFOS or PFOA

Maintaining your water treatment system

All water treatment devices require periodic maintenance to ensure they continue to effectively remove contaminants and provide safe drinking water. Water treatment devices have varying maintenance needs due to differences in system design, use capacity, and treatment technology. Maintenance schedules and requirements can include filter media or cartridge replacement after a set period of time (e.g., 6 months) or after filtering a set volume of water (e.g., 500 gallons). Additionally, some systems include smart indicators or sensors that signal users when maintenance is needed, while others rely on users manually tracking time or water usage. Therefore, follow the manufacturer's operation and maintenance guide, as well as using their approved component replacement parts to ensure that the devices continue to work as expected over time.

Additional Resources

• Frequently Asked Questions (FAQs) about PFAS