PFAS (Per- and Polyfluoroalkyl Substances) PFAS, or per- and polyfluoroalkyl substances, are man-made compounds widely in use in a number of products since the 1940s. When products containing PFAS are used and discarded, they can release PFAS into the environment, including into drinking water sources. Pasco County Utilities, along with other water utilities throughout the region and across the United States, is participating in a study in 2023 to test raw and treated drinking water to collect data to help the EPA set regulations for PFAS.