Per and Polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that include Perfluorooctanoic acid (PFOA), Perfluorooctanesulfonic acid (PFOS), and Generation X (GenX). Known as “forever chemicals,” PFAS are persistent in the environment and the human body. PFAS can be found in food packaging, commercial household products including stain and water repellent fabrics, nonstick products, polishes, waxes, paints, cleaning products, and fire-fighting foams. Recent studies have suggested evidence that exposure to PFAS can lead to adverse health outcomes in humans, especially because they stay in the body for long periods of time. Although PFOA and PFOS are no longer manufactured in the United States, they are still produced internationally. They can be imported in the U.S. in consumer goods as carpet, leather and apparel, textiles, paper and packaging, coatings, rubber, and plastics. These PFAS laden consumer goods pose an emerging risk to the wastewater treatment plants (WWTPs). No federal regulatory thresholds currently exist for PFAS air emissions. U.S. Environmental Protection Agency (EPA) recognizes PFAS air emissions as one of the significant routes for PFAS releases to the environment, but limited knowledge exists on PFAS air emissions. Airborne exposure can happen through direct inhalation and indirectly through deposition to watershed and water supplies. Once airborne, PFAS can occur in a gaseous state or be associated with Particulate Matter (PM) or other aerosols suspended in air. For example, the compound 8:2 Fluorotelomer Alcohol (8:2 FTOH) is a neutral volatile precursor compound that exists in gas phase that can degrade into PFOA, PFOS, and Perfluoroalkylacids (PFAA’s). WWTPs are a major source of PFAS releases into the environment. In addition to the releases in effluent and sludge, wastewater typically passes through a series of wastewater collection and treatment units before discharging to a receiving waterbody. Many of the units are open to the atmosphere and allow for the potential volatilization of precursors to PFAS from the wastewater. This paper will focus on characterizing volatile PFAS-related emissions from the WWTPs using a general fate model, the Wastewater and Treatment Emissions Routine (WATER9) Model developed by the EPA. This study will help WWTP owners understand and quantify the potential PFAS-related air emissions from WWTP processes.
