How to Remove PFAS From Water at Home

PFAS, or per- and polyfluoroalkyl substances, have become a hot topic in recent years, and for good reason. Known as “forever chemicals,” these compounds earned their nickname for their extremely persistent makeup. PFAS can last for thousands of years without breaking down, unlike biodegradable materials. These chemicals can be found in soil, food, materials in our homes and workplaces, and our water. Given their ubiquity and potential health risks, there is rising concern among the public about how to remove forever chemicals from water. Though PFAS are still not fully understood, reverse osmosis (RO) systems have been documented to help reduce these chemicals in water.

What Are PFAS “Forever Chemicals”?

PFAS are man-made chemical compounds that include perfluorooctane sulfonate acid (PFOS) and perfluorooctanoic acid (PFOA). These synthetic compounds are widely used due to their unique properties that repel water and grease, finding applications in numerous industrial and consumer goods. As a result, PFAS persists in the environment. Their long life coupled with extensive use, misuse, and improper disposal over the years has resulted in the contamination of drinking water at various locations throughout the United States and other parts of the world. The Environmental Working Group has documented PFAS across 1,593 sites as of their most recent report in May 2024, though their reports don’t include possible locations where measures are in place to reduce PFAS in water.

Are PFAS Harmful to Human Health?

From 2005 to 2013, a scientific panel consisting of three highly regarded epidemiologists studied the effect of PFAS on human health. They concluded that there was a probable link between PFAS and many illnesses, including high cholesterol, thyroid disease, cancer of the kidneys, certain types of colitis, and testicular cancer. More recently, a Harvard University study indicates that the harmful health effects of PFAS may have previously been underestimated. The Harvard study adds several more illnesses to the list that could result from PFAS, including decreased fertility and increased risk of asthma.

How Do Forever Chemicals Get Into Drinking Water?

For decades, PFAS disposal was not heavily regulated. Manufacturing firms disposed of materials containing PFAS by dumping liquids onto the ground, flushing liquids down sanitary sewers, or burying products in landfills. Firefighters often sprayed the ground with foam containing PFAS which was then washed away. Through seepage, forever chemicals eventually found their way into groundwater, which is the source of most drinking water. Additionally, unwary residents inappropriately disposed of materials containing PFAS, further contaminating groundwater reserves.

Recent Government Response

The United States Environmental Protection Agency (EPA) issued a health advisory regarding the presence of PFAS in tap water. This recommends the amount of PFAS in drinking water be limited to 70 parts per trillion. When both PFOAs and PFOSs are found in drinking water, the EPA recommends that the combined total of the two be limited to 70 parts per trillion. The EPA set this specific concentration level to guard against mounting health risks. However, there is no current federal mandate to stop manufacturers from using PFAS in products, though some have voluntarily done so.

How to Test For PFAS In Water At Home

If you’re concerned about your home’s water, you can purchase a laboratory test kit to test your water. These kits provide instructions on how to collect the water sample and send it to a certified lab for testing. Test kits that use strips do not work for PFAS, so please keep this in mind when purchasing a kit. Certified laboratories use the EPA’s 533 and 537.1 methods to effectively measure 29 different PFAS in drinking water.

Does Boiling Water Remove PFAS?

No, boiling your water will not eliminate PFAS. In fact, it could actually increase the concentration of PFAS in your drinking water. While it is true that water contaminated with bacteria is safe to drink after boiling it, the same is not true for PFAS. Bacteria cannot survive at elevated temperatures, so they are destroyed when water is boiled. However, PFAS are resistant to heat. After all, one of their primary uses in the past has been in nonstick cookware. When you boil water, the amount of water is reduced because of evaporation, but the amount of PFAS remains constant, so the concentration level actually increases.

Can PFAS Be Filtered Out of Water?

Many homeowners have the same question: do water filters remove PFAS? The answer is complicated. Some water filters, like reverse osmosis systems, are quite effective at reducing the concentration of forever chemicals. In an EPA study, reverse osmosis (RO) separation was found to be up to 99% effective at removing PFAS, including smaller chains, which are the most difficult to filter.

How Does RO Reduce PFAS?

RO systems are one of the best options currently available to greatly reduce the presence of PFAS when used as a point-of-use rather than a point-of-entry solution. By point-of-treatment, we mean RO systems are most effective at filtering PFAS when installed near the fixtures you use for drinking water, such as underneath a kitchen sink.

Forced water makes its way through RO systems at high pressure, which pushes water molecules through a semi-permeable membrane. Once water molecules pass through the membrane, they are divided into two streams. Permeate, also called product water, is the cleaner water with fewer contaminants. The concentrate, or the reject water, contains larger molecules and contaminants that are unable to pass through the filter, such as salts, microorganisms, and chemicals. Only the permeate makes its way through the system and to plumbing fixtures for drinking.