The processes of pollutant migration from a solid waste landfill are studied for two cases corresponding to the violation of the integrity of the insulating layer. The first case models the violation of the integrity of the insulating layer of a settling pond at the seam. It is assumed that at the junction of the sheets of insulating material a crack is formed, passing through the entire bottom of the pond, which is a source of pollutant penetration into the soil. In the second case, wear of the insulating material of the landfill body due to the duration of operation is considered. An assessment of the impact of the object on the environment is carried out through the penetration of filtration waters into the thickness of the ground rocks of the foundation of solid waste placement facilities. To study the features of pollutant distribution and to determine migration parameters, data from a set of field and laboratory studies in the area of the planned solid waste disposal site were used. A numerical model of the hydrodynamics of substance migration in the soil layer of the solid waste disposal site foundation was constructed. The process of pollutant movement is described by the dry residue index. Factors that have a significant impact on pollutant migration are taken into account, the main ones being convective transfer, diffusion and the slope of the earth's surface, which are taken into account in the mathematical description of the model.