What Are PFAS, and Why Are They in our Drinking Water?

What Are PFAS, and Why Are They in our Drinking Water?

Few tap water contaminants have garnered as much attention in the last few years as PFAS, also known as the "Forever Chemical."

PFAS stands for per- and polyfluoroalkyl substances, a group of manmade chemicals that began being manufactured in the United States and around the world in the 1930s.1 They contain linked chains of carbon and fluorine, one of the strongest bonds found in nature, and that means they don’t degrade easily. They are stable in water and in the human body and in the environment. In fact, one of the only ways to destroy them is to subject them to temperatures above 1,000 degrees Centigrade, and even that method has been called into question.2

When they say “forever,” they really mean it.

There are roughly 4,700 different chemicals that fall into the category of PFAS, but the two that are most common are PFOA — perfluorooctanoic acid — and PFOS — perfluorooctane sulfonate. Though they’re no longer manufactured in the United States, they’re still manufactured around the world and imported into the country in products that we use every day, like takeout food containers and microwave popcorn bags. And before their use was curtailed in the early 2000s they were released by chemical companies, used to coat non-stick cookware, and incorporated in stain-and water-repellent fabrics, polishes, paints, cleaning products, and fire-fighting foams.6

They’re still very much with us because of that ‘forever’ thing. Our landfills are filled with them, and so is our drinking water. And that last part is the most frightening of all, because it means that PFAS are in our bodies. An alarming study published in the journal Environmental Health Perspectives in 2007 reported that in a study designed to represent the U.S. population, PFOS and PFOA serum concentrations were measurable in 98% of participants.3 This is particularly troubling, as dozens of studies have linked PFAS exposure to health conditions ranging from infertility and low birth weight to thyroid disease, immunosuppression in the young, and several types of cancer.

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Once PFAS enter the body, they are persistent. Their half-life — the amount of time that it takes for their levels in the body to go down by half — is approximately four years, and of course the chemicals aren’t taken in on a one-time basis.4 Exposure is frequently ongoing, particularly in areas where the chemicals are present in the drinking water system. And according to the Environmental Working Group, PFA contamination is “likely detectable in all major water supplies in the U.S.,” and far more prevalent than publicly reported by state environmental agencies.5

Despite their dangers, PFAS are unregulated. There is no requirement that utilities test for them, or that they report the results of any independent testing that they do conduct to the EPA. And the sampling program that the agency conducted in 2015 relied on a much higher minimal level than many health advocates believe is safe. It only tested drinking water systems serving more than 10,000 people, and has not been repeated since.

In response to the big-picture problem of PFAS in the environment, researchers are working to find ways to eliminate them from water supplies, and ultimately to destroy them using electrochemical, thermal, and ultrasonic treatment methods that they hope will completely break the chemicals down.7 In the meantime, consumers concerned about their health and the health of their families are advised to limit their exposure to PFAS chemicals by avoiding stain-resistant carpets and upholstery, to avoid eating microwave popcorn and foods packaged in take-out boxes, and to use a home water filter that has proven effective at removing PFAS. Aquagear’s water filters are designed and tested to effectively remove over 99% of PFOA and PFOS, using filter technology that is exactly what the EPA and other experts recommend as the best available option for removing PFAS from drinking water.8


  1. 2 PFAS Chemistry and Naming Conventions, History and Use of PFAS, and Sources of PFAS Releases to the Environment. Retrieved from ITRCweb.org. (ND)
  1. EPA, DOD Finally Acknowledge Hazards of PFAS Incineration. Retrieved from SierraClub.org (August 26, 2020)
  1. Polyfluoroalkyl Chemicals in the U.S. Population: Data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and Comparisons with NHANES 1999-2000. Retrieved from Environmental Health Perspectives (November 2007)
  1. Public Health Statement – Perfluoroalkyls. Retrieved from the Agency for Toxic Substances and Disease Registry (August 2015)
  1. PFAS Contamination of Drinking Water Far More Prevalent Than Previously Reported. Retrieved from Environmental Working Group (January 22, 2020)
  1. Basic Information on PFAS. Retrieved from the Environmental Protection Agency website (ND)
  1. ‘Forever chemicals’ no more? These technologies aim to destroy PFAS in water. Retrieved from Chemical & Engineering News (March 25, 2019)
  1. Reducing PFAS in Drinking Water with Treatment Technologies. Retrieved from Environmental Protection Agency website (August 23, 2018)