Subsurface contamination by nonaqueous phase liquids, such as 1,2,4-trichlorobenzene, is a widespread problem at numerous sites. In this work, the behaviour of 1,2,4-trichlorobenzene in the saturated zone was investigated using two natural porous media. To this end, cylindrical columns were packed with different materials and the initial water saturation was displaced by loading a constant level of trichlorobenzene on top of the porous bed. The experiments were carried out with different configurations to simulate natural media with several stratigraphic units. Also, the effect of pressure gradient on nonaqueous phase liquid flow was investigated. Both the pressure gradient and the configuration of the layers of porous media have shown a strong effect on water recoveries and fluxes through the column.