Pavia, Ashley2024-01-242024-01-242023https://udspace.udel.edu/handle/19716/33918Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals that have been widely used in manufactured and commercial products. They are persistent emerging contaminants that have been linked to adverse health effects in wildlife and humans. Few studies have assessed how PFAS compounds are transported and distributed throughout coastal watersheds and their effects on coastal ecosystems. This study assesses the spatial distribution and composition of PFAS in a tidal salt marsh and investigates how geochemical and hydrological conditions affect their fate and transport. We used St. Jones Reserve, a tidal marsh positioned between a military base and Delaware Bay, as the study site. We collected groundwater, porewater, and sediment from seven sites that span across three marsh zones with contrasting geochemical and hydrological conditions, and surface water from the tidal creek at high and low tide. Our study reveals a consistent pattern in the vertical distribution of PFAS within the salt marsh and elevated PFAS concentrations in the subsurface environment across seasons. Our findings highlight dissolved organic carbon (DOC) as a potential factor influencing the distribution of PFAS in the marsh ecosystem. The results of this study improve our understanding of PFAS mobility in the environment and the factors that affect their fate and transport as they migrate to the ocean. The information generated in this study can be used to develop models to predict PFAS fate and transport and strategies for protecting coastal water supplies and ecosystems.Polyfluoroalkyl substancesHydrological conditionsSpatial distributionSubsurface environmentCoastal water suppliesThesis1439062061https://doi.org/10.58088/2mpa-8t242024-01-22en