The interaction between the turbulent wake, created by a tailings pond dike and the low level emissions at the Syncrude Tar Sands Plant has been investigated using wind tunnel model simulation. At the large Reynolds numbers experienced by model and full-scale dike the flow remains attached to the downwind side of the dike, with no recirculation zone. The effects on dispersion of three dike heights are compared to the flat terrain case for one typical low level source in the dike wake. By increasing the dike height, a small reduction in ground level concentration results, which is consistent with the observed increase in crosswind plume spread relative to vertical spread. Simple Gaussian plume model predictions are compared to wind tunnel observations, and are shown to be accurate estimates of ground level concentrations. At the Syncrude plant site the tailings pond containment dike is located about 1.2 km north of the main stack. This containment dike may in time reach a height of 50 meters, about 25 percent of the main stack height and about the same height as the low level sources. Eventually, the dike will become the predominant topographical feature in the neighborhood of the plant site. The effect of this dike on the dispersion of material from low level sources within the plant site forms the basis for the present investigation.