OPPORTUNITIES AND CHALLENGES OF INTEGRATED LARGE SCALE PFAS MODELING

Perfluoroalkyl substances (PFAS) have been observed around the world in air, water, and soil. Recent research and monitoring studies have alluded to the widespread presence of PFAS, but most observe the impact of PFAS as a snapshot in time and space. In an effort to better understand PFAS fate and transport in the environment, computational models have been developed. For this study, we synthesized the model applications of PFAS fate and transport via water medium through surface water, vadose zone, groundwater, streamflow, as well as their uptake and accumulation in plants and aquatic organisms. In addition, the system under this study is permeable to incoming (sources) and outgoing (sinks) PFAS compounds. Ultimately, knowledge gaps in modeling PFAS for each subsystem (e.g., surface water) area were identified. From there, a case study was performed to highlight the shortcomings of widely used models for PFAS fate and transport within a large and complex watershed. With a large number of PFAS using industries, Michigan is at the forefront of PFAS sampling. Therefore, the study area chosen was the Huron River watershed, a highly PFAS impacted watershed in Southeastern Michigan. The results showed the importance of organized monitoring studies and model improvements to better understand PFAS fate and transport in a large watershed.