Methods to improve air quality emission and meteorological model input data records and validation techniques used to verify calculated annual, monthly, and daily calculations at ground level for the CRSTER model are described. Due to the limited nature of verification data and unique polar co-ordinate receptor grid network, a point-spatial validation approach, involving calculations along the most important windrose axial directions relative to the GCOS source, is advanced in annual time studies covering 1975 and 1976. Selected Syncrude, Shell Hartley Creek, and GCOS monitor site observations are also utilized in the two studies on an annual, monthly and daily basis for statistical comparison with model results on a point-spatial verification basis only. As .in the axial validation, this statistical verification excluded objective analysis smoothing of calculated concentrations. Results are related to similar studies in a discussion of CRSTER's modelling capabilities. Environmental impact analyses for both time studies, including levels of confidence assigned to concentration estimates are described. A guide for future use of current and future versions of the model in the Oil Sands study area is advanced.