LAUSR

Abstract The contaminant transport of perfluorooctane sulfonate (PFOS) through the base of a municipal solid waste landfill lined by a single composite liner comprised of a geomembrane over a geosynthetic clay liner (GCL) and a 3.75 m-thick attenuation layer underlain by an aquifer is examined. Both pure diffusive transport and advective transport through holed wrinkles are modelled. The peak concentrations of PFOS predicted for the aquifer beneath the landfill are compared to the maximum allowable PFOS concentration established by Australia, Canada, Europe, and various US states. The results show that (a) in most cases with zero leakage and pure diffusive transport, regulatory limits are met; however, (b) if there are holed wrinkles in the geomembrane, the impact is highly dependent on the length of holed wrinkle per hectare, the geomembrane-GCL interface transmissivity, and the GCL hydraulic conductivity. Factors affecting the length of holed wrinkles are discussed. In many of the cases examined, the peak concentrations of PFOS in the aquifer exceed the limits set by the different jurisdictions, indicating that a single composite liner may not be sufficient to contain PFOS acceptable level and recommends that realistic contaminant impact calculations be performed in each specific case.