This study considers the problem of organic matter decomposition in alpine-type caves. The aim of this study was to evaluate the decomposition of food waste and fecal sludge in the cave conditions by using the clay sediments of the Snezhnaya cave. The model experiment was conducted, where the cave conditions were simulated. In the experiments, we used the following products: mashed potatoes, buckwheat and rice porridge, and fresh fecal sludge. Three types of standard waste management were modeled: they were placed on the soil, buried in the soil and scattered with carbide sludge. The waste decomposition was evaluated by two methods: by the amount of carbon remaining in the soil and by the amount of carbon dioxide emitted from the system. As a result, it was revealed that the decomposition of waste that was buried in the substrate occurs faster. Buckwheat porridge and mashed potatoes decompose slower. In all variants of the experiment, decomposition of fecal sludge in the soil revealed bacteria of the Escherichia coli group and Clostridium perfringens. It was revealed that when waste was filled with mined carbide sludge, the decomposition of organic matter slows down and the number of sanitary-indicative microorganisms grows. © 2021, Procedia Environmental Science, Engineering and Management. All Rights Reserved.