Environmental quality in St. Petersburg is driven by structure and culture of production, specific features of placement of productive forces and also geographical location and climatic conditions.
There is no such megapolis in the world located on 60º northern latitude with this amount of production and social objects. Unfortunately, both the production and social objects located in the territory of the city are characterized by high resource and power consumption that has a negative impact on the environment. Besides, settling down in the mouth of Neva river, the city is forced to take in a part of the sewage arriving from other territorial subjects of the federation through its main waterway. The current environmental situation is influenced also by a cross-border air transfer of pollutants from adjacent areas.
Environmental quality in the city is driven by air water pollution, city land use, recycling of production and consumption waste, green space conditions and many other factors. The nature of pollution and their influence differ depending on the environment they affect mostly — atmospheric air, surface water and groundwaters, soil, green space.
Pollution of the air is formed, as it's told above, under the influence of transfer of pollutants from adjacent areas and also under the influence of mobile and stationary sources emissions. Automobile transport gives the main part of air pollution in St. Petersburg that is why air near highways with heavy traffic of cars is polluted in especially high degrees.
Within St. Petersburg there are more than 600 reservoirs and 390 water courses. The condition of water facilities in the city is described as "polluted" and "moderately polluted". The main sources of pollution of surface water is waste and storm waters discharge without treatment. In 2008 one of the most important stages of construction of the Main collector of the sewerage in the Northern part of the city was complete, which has been started back in the 70s, that will allow to stop discharge of sewage into city waterways without treatment in the coming years.
In St. Petersburg and its suburbs groundwaters are distributed widelye. The subsurface of the city contains not only fresh drinking water but also mineralized one which can be used for pouring for medical and balneological purposes in sanatoria of Kurortny and Petrodvortsovy precincts. The groundwaters located in the city subsurface is relatively clean.
The current state of soil and ground is significant for environmental assessment since soil is of interest as an integrated indicator of ecological situation and as a source of secondary pollution of the ground layer of atmosphere, surface and ground waters. By prevalence and toxicological influence pollution of soil can be caused by organic and inorganic toxicants. Degree of soil pollution is extremely non-uniform and can be driven both by historical factors connected with development of the city, and technogenic influence.
Green space has various functions, main of those are: improvement of air quality in the city due to absorption of carbon dioxide and release of oxygen, decrease in level of city noise, dust content and gas contamination in the air and also the microclimate improvement on account of cool-down of air in hot weather because of moisture evaporation, wind protection, emission by plants of phytoncides - special volatile chemicals capable to kill pathogenic microbes.