In fine grained soils, the hydraulic conductivity under sat- urated conditions is controlled by the microstructure of the soil matrix which in turn depends on the type of the fine material (e.g., clay mineral) present in the soil, the composition of the exchange- able cations, and the electrolyte concentration in the pore water system (Rao and Matthew, 1995; Ruth, 1946; Wu et al., 1990; Ndiaye et al., 2007). The measured permeability coefficient at a given porosity is significantly dependent upon the nature of the permeating medium. For example, clays are much more permeable to gases and most organic liquids than to water.