[en] A Very Low Level Radioactive Waste disposal site is being planned in El Cabril, Spain, where a Low and Intermediate Level Radioactive Waste disposal site is already located. As part of the ongoing safety assessment for this new facility, we have modelled the transfer of chemical pollutants from the disposal site to the underlying aquifer. The conceptual model is based on the water transport due to the infiltration of rain through the disposal cell. The source term is given by the dissolution of the initial inventory limited by sorption in cement (the main form of the waste) and secondary phase solubility. Several assumptions have been made: all protective layers are degraded, the system is saturated and the water flux is stationary and unidimensional in the vertical direction. A compartment modelling approach has been followed, and the system has been divided in four compartments: Top clay layer, Waste, Bottom clay layer and Subsoil. The latter acts as a sink representing the discharge to the aquifer. Advective and diffusive fluxes are defined between the compartments taking into account hydrological, geochemical and transport properties of the different materials and compounds. The results of the simulation (up to 106 years) show that there is an initial increase in the contaminant release to the aquifer due to the leaching of the waste by the infiltrating waters until a maximum is obtained. In most of the elements the maximum is given by their respective solubility limit and therefore the release is constant during all the time the concentration in the pore water is controlled by solubility. (author)