Methods for assessing the state of landfills for municipal solid waste (MSW) at various stages of the life cycle and their impact on the environment are considered. The results of a study assessing the degree of stability of waste of different periods of disposal according to physicochemical, biochemical, thermal parameters are presented. Based on the results of physicochemical and biochemical parameters, the stages of biodegradation and the degree of decomposition of the waste are determined relative to the disposal period of the waste. It was proposed to assess the stability of waste in an array of landfill by a number of thermal parameters of waste: the magnitude of thermal effects, the temperature of heat generation peaks, the rate of mass loss, the ratio of specific enthalpies of dry matter (DM) and organic dry matter (ODS). A method for integrated assessment of the stability of MSW in an array of landfill was developed, including the establishment of waste stability classes, boundary values of stability indicators and periods of their achievement. The method is intended for geoecological assessment of the condition of disposal of MSW and justify the choice of technical measures to reduce emissions.