In large cities, surface sewage represents large amounts of contaminated water. Analysis of the composition of waste water showed that the main pollutants are suspended substances and petroleum products. The amount of surface runoff is affected by hydrometeorological conditions, such as the duration and intensity of the rain, the amount of precipitation in the winter. To reduce the negative impact on surface water runoff from residential areas and highways, it is necessary to organize the collection of surface sewage, drainage system and subsequent cleaning. In this article, on the example of data from St. Petersburg, the composition of surface wastewater, the dependence of the concentration of pollutants on the amount of atmospheric precipitation are considered. Effective methods for their purification before discharging into a body of water are proposed in accordance with the provisions of the Federal Law "On Environmental Protection”.