Modelling the transport of shipborne per- and polyfluoroalkyl substances (PFAS) in the coastal environment

Per- and polyfluoroalkyl substances (PFAS) are presently essential ingredients in aqueous film forming foam (AFFF) used for fire-fighting, but are also pervasive environmental contaminants. The use and subsequent release and transport of AFFF in the ocean environment from marine vessels has not been studied to date. A numerical model (Delft3D) was rigorously calibrated and validated for the hydrodynamics, and used to predict the transport of PFAS released instantaneously into a large harbour (Halifax Harbour, Nova Scotia) that is representative of coastal environments in eastern Canada and other parts of the world. The numerical model results indicate that PFAS released in the presence of strong winds and waves during a storm will travel up to 31 km in 2 days, approximately 40% farther than PFAS release during a time period dominated by tidal currents with light winds and small waves (