Old environmental burdens have been an unresolved issue in the Slovak Republic and other countries for a long time. Old burdens have a serious impact on the environment, including human health. The main goal of the dissertation thesis is to explore the impact of gudron waste on the environment with a focus on landfills Predajná I and Predajná II. The theoretical part of the work summarizes the impact of petroleum substances on the environment and describes the basic principles of analysis and assessment of environmental risks. The practical part defines in detail the landfills of Predajná I and Predajná II. We found out that in both landfills, waste leaks into the subsoil and there is a risk that the top layer of gudron might spill into the surrounding environment. In addition to petroleum substances (determined as non-polar extractable substances), other dangerous substances are contained in gudrons (for example As, PCB, Hg, Cr and others). The thesis is focused on the evaluation of non-polar extractable substances’ concentrations in groundwater, surface water and soil.The topicality of the risk by means of indication (ID) and intervention (IT) criteria for the pollutant was assessed within the risk analysis of the polluted area according to the directive of the Ministry of the Environment of the Slovak Republic No. 1 / 2015-7. Water was monitored in nine wells around the landfills during the years 2015 – 2019. Based on the results, it can be concluded that groundwater contamination is unlikely to occur. The presence of non-polar extractable substances in concentrations exceeding the permissible limits (0.1 mg.l-1) was determined by evaluating well water taken directly from a well used by the population. The exceedance of the IT limit value of 1000 mg.l-1 more than twice at a distance of 1 m from the landfill was discovered during the soil impact assessment. The presence of non-polar extractable substances was also discovered at a distance of 150 m, which may be caused by the spread of contamination. The ecotoxicity assessment of waste is also a part of the environmental risk analysis. Ecotoxicological tests have shown that both the solid phase and the aqueous phase (top layer) of gudron waste are toxic to aquatic and terrestrial organisms.When evaluating the leachability of waste, it was found out that up to 66% of organic matter is leached in distilled water in 24 hours. It can be assumed that in real conditions, if intense and long-term rain activity occurs, there will be waterlogging or leaching of pollutants. The biodegradability test proved that the waste is degradable by microorganisms only after considerable dilution. We tested the use of common sorbents for oil capture as one of the possible solutions for smaller leaks from gudron landfills. Good results were obtained by using a peat sorbent and a hydrophobic flake sorbent.