ABSTRACT: One of the major problems facing industrialized world today is the contamination of soils, groundwater, and sediments with hazardous hydrocarbons. Vlkanová (in the Central Slovakia), is one of the places where sediments are decontaminated using the technology of bioremediation. A detailed study of the area and analysis of the real conditions for use of a specific decontamination method identified the optimal process of bioremediation that is now in progress in Vlkanová. In general, the effect of this method depends on the level of contamination, present microbiological population, and improvement of condition for targeted processes of microbiological degradation. Biodegradation used in Vlkanová consists of the following steps: pumping groundwater, stripping the pumped water, adding necessary minerals, nutrients, oxygen, and selected multiplied microorganisms. Finally, this prepared inoculum is added to the soil through application wells. The whole process is monitored and optimized according to the changing conditions.