The aim of the bachelor thesis is to describe the influence of the old dumps Predajná I and II on the environment. In theoretical part, the basic knowledge about the petroleum, petrochemical industry and it is pointed on the petrochemical industry impact on the environment with focusing on the creation of hazardous waste – acid tars. The main part of the work is devoted to hazardous waste landfills, which are located in the Predajná village. Acid tar ponds Predajná I and II are classified in the priority status group (K> 65) according to the environmental load classification, and since 2013 they are regularly monitored for pollutants‘ concentrations in soil, groundwaters and surface waters.