Abstract: A numerical model to simulate miscible pollutant transport through unsaturated/satu-rated soils is presented. The model is composed of the two coupled phases: the hydromechanical analysis of the two immiscible fluids through the deforming porous medium to determine the velocity fields of the porous water and air flows and the saturation degrees; the pollutant transport analysis through the porous medium. The emphasis of the present paper for the numerical modelling is specially given to the second phase. T...