The analysis of engineering and geological conditions of Primorskiy district of Saint Petersburg associated with the prospects of its areas development up to the year 2025. Its structural and tectonic conditions are represented. Results of microbiological analysis of soils from the section of Juntolovskiy reserve are given. The research of microbial flora of Lakchtinskoye swamp peats are carried out. The analysis of basic engineering and geological problems related with microbial activity is given. The main natural and technogenic sources of underground water and soils contamination are considered, and also some measures that provide longterm com-petence of constructions of different appointment are recommended.