On the basis of extensive current measurements in Lake Ontario near Pickering, empirical impulse response functions have been obtained which permit computation of coastal currents in this region from routine wind observations at Toronto Island Airport. The model may be expected to simulate about 75% of the variance of the actual currents in this region and to produce very reliable indications of alongshore current directions and reversals. The empirical model for coastal currents has been combined with a stochastic dispersion model using microcomputer technologies to predict the behavior of contaminant spills in the nearshore zone of Lake Ontario. The model has been verified with the thermal effluent data collected near the Pickering Nuclear Power Generating Station.