One oil extraction plant (GCOS) has been in operation for several years, the go-ahead has just been given for a second plant (Syncrude), a third (Shell) has an application pending, and the current energy crises may well accelerate the rate at which additional plants go into production during the next decade. This poses the problem of how to develop the oil sands on an economic basis while ensuring a minimum of undesirable effects on the total environment of the oil sands area and the surrounding region. This report will concern itself only with the atmospheric environment and where necessary with the interface between the atmosphere and the earth’s surface in terms of absorption or deposition of pollution. Although \"containment at source\" is the most effective way of protecting the atmospheric environment, current technology does not allow achievement of this goal either today or probably for some considerable time in the future. To be realistic we must therefore accept the fact that some pollution will enter the atmosphere. The basic question to be answered is: \"How much can reasonably be allowed?\" The emissions from the present plant under normal operating conditions are approximately 350 long tons of SO2 per day. Under upset conditions the plant is allowed to emit at the rate of up to 930 long tons of SO2 per day for short periods. Values for the proposed Syncrude plant will be only slightly less. Thus, while the present plant is emitting at a rate of less than one-tenth that of the Sudbury area, the combined effect of several plants in a small confined area of the Athabasca Valley could produce within ten years total emissions approaching those of the Sudbury area, or even exceeding them in the case of upset. It is therefore essential that the environmental degradation that has occurred in the Sudbury area not be allowed to occur in the Alberta Oil Sands. To do this the maximum possible use will have to be made of meteorological knowledge for the location, design and operation of the extraction plants, in order that the effects of air pollution in the area are minimized.