During the percolation of the waste deposit subsoil, it is well known that physical and chemical actions occur. To carry out leachate action on subsoil, TDR probes were calibrated with water and leachate. Calibration curves were then used to follow water content profiles in the soil during the laboratory tests in lysimeter and in situ tests. In situ, leachate action on subsoil was observed during deposit clinker waste percolation. Leachate chemical analysis before and after percolation shows that soil modifies leachate pH and electrical conductivity. The percolation of leachate in soil provokes the sorption of some ions like K+, Na+ and the desorption of some others like Ca++. It is observed that the soil reduces the leachate solute concentration. TDR measures enabled to determine soil electrical conductivity. It was observed that during leachate migration in the soil layers, soil conductivity increases more in upper layers than in lower layers. The soil layers purified leachate before equilibrium water content was reached. When the leachate flows out the soil layer, soil electrical conductivity becomes higher in lower layers. It is noticed that the theoretical saturation water content never reached in the soil layers. During in situ test, it is observed that the final soil volumetric water content is greater than the soil initial porosity. This result proves that leachate percolation allows fine particle movement which increases soil porosity. It is seen that the percolated leachate turbidity increases during the percolation.
Waste containment liners require very low hydraulic conductivity. Many permeability tests indicate that the coefficient of permeability depends on leachate chemical properties [Mitchell et al. 1987, King et al. 1993, Alimi et al. 1999,]. It is observed that this coefficient increases when the used permeant is a leachate instead of water.
