The article discusses environmental issues that arise when municipal solid waste (MSW) landfills are closed. Considering the data of soils state near the landfill site, the article also estimates potential danger of landfill gas components for the health of the population living near the landfills and MSW dumps as well as analyzes data of the state and degree of landfill substrate decomposition at the transfer station in the town of Vidnoye (Moscow region). The article provides a screening of species composition and activity of the main groups of microorganisms in the soil of the landfill and explores the prospects of using these microorganism communities for accelerated biodegradation of the dump’s body. © IAEME Publication.