The development of power production system requires evaluation of primary SO2 emissions converting into secondary aerosol (sulfates) within the considered area (a local zone). As a first approximation, the tentative estimations of conversion and precipitation of sulfur-bearing compounds can be obtained using data of chemical analysis of snow cover samples collected late in winter. The technique was developed using the data of detailed snow sampling on the territory of Irkutsk for four years (2000-2003) and in Slyudyanka and its outskirts for two years (2002-2003). The integral rates of precipitation of the sulfur-bearing compounds were determined; the values obtained for Baikal region in winter proved to be essentially different from those in Europe. The data on the background pollution of precipitation is shown to be useful for determination of the contribution of long-range transport to sulfate precipitation on the urban territory.