AAAS EPI Center and GLLC Roundtables

Treatment and Mitigation of PFAS in Drinking Water | AAAS EPI Center

PFAS and Drinking Water A number of the most-researched per- and polyfluoroalkyl substances (PFAS) have been linked to human health issues at small doses and detected in drinking water and drinking water sources throughout the United States. A class of thousands of synthetic organic chemicals, PFAS have been used in a variety of industrial and consumer applications from clothing and food wrappers to firefighting foam, and after decades of use, PFAS contamination is widespread 1 . The chemical properties of PFAS, particularly the strength of the carbon-fluorine bonds, make them difficult to treat and remove using conventional water treatment processes. This guide introduces established drinking water technologies that can remove PFAS from drinking water, as well as emerging and innovative PFAS treatment technologies still in development. For more information on the basics of PFAS chemical properties, toxicity, monitoring and more, please see the AAAS EPI Center’s PFAS and Drinking Water: A Scientific Overview and PFAS Monitoring and Occurrence in Drinking Water. In 2016, the U.S. Environmental Protection Agency (EPA) developed a lifetime health advisory (HA) level of 70 ng/L or parts per trillion (ppt) for two PFAS: perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), individually or combined, but this health advisory is not an enforceable standard. In the absence of enforceable federal regulations, many U.S. states adopted or proposed drinking water standards for specific PFAS. PFAS cannot be easily removed by most municipalities’ existing conventional water treatment technologies. Effective PFAS treatment technologies can be costly and vary in their effectiveness in removing different PFAS. Therefore, water utilities typically approach PFAS treatment by conducting preliminary small-scale studies to assess treatability and determine the best treatment for the individual water system. Results can vary significantly based on site-specific factors such as water quality, site availability, and waste treatment options. Removing PFAS from Drinking Water Existing advanced treatment technologies are able to remove PFAS from water, but they vary in PFAS treatment effectiveness and can be costly. PFAS removal effectiveness can depend on the PFAS properties (e.g., chain length, functional groups), and other water quality constituents that may interfere with treatability 2 . Long-chain PFAS are the most commonly found PFAS in the environment and are sometimes referred to as “legacy” PFAS, as they have been in use for their stable, water repellent properties since the 1940s and most were phased out in the United States in the early 2000s 3 . Alternatively, short-chain PFAS have been used as replacements to long-chain PFAS; they can be highly mobile in water and soil and are difficult to break down 1 . Advanced treatment methods for PFAS removal also come with operational challenges, including changes in day-to-day operations, expensive costs for construction and operation, and the production of PFAS- contaminated waste that requires proper management and disposal. In addition to treatment at water facilities, PFAS contamination can be controlled through several other measures such as environmental

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