Influence of soil-water conditions on the migration of pollutants in the vicinity of municipal landfill sites

Abstract

The time taken for a pollutant to migrate from the potential source to the groundwater reservoir is one of the main criteria in evaluating groundwater hazards. This process depends on the lithology and thickness of the deposits forming the basement of the landfill site as well as on the depth to the groundwater table, infiltration and the concentration of effluents. This paper focuses on the analysis of the influence of particular factors on the transport of pollution, based on field analyses and numeric modelling. The Femwater program was applied in numeric calculations. This program solves a 3-D modified RICHARDS equation for groundwater flow by the finite elements method (FEM), and the mass transport equation using the hybrid LAGRANGE - EULER finite elements method.The results obtained allow evaluation of the influence of the soil-water environment factors that determine the rate of pollution distribution and are the basis for forecasting the processes concerned in the migration of pollutants. The problem was solved in two examples of municipal waste landfill sites characterised by a different geological setting, one located on the supra-flood terrace in the River Vistula valley and other on the Wołomin Plateau.