Combining local measurements, modeling and scaling theory of capillary barriers

Capillary barriers fullfill the requirements for a top cover in the sustainable landfill strategies, as they may allow controlled water infiltration, aeration, gas permeation. A key point for capillary barriers design is determining the maximum water discharge that will enter the landfill. Fine and coarse grain materials for the different layers of the cover must be chosen in order to limit infiltration to this threshold discharge. A mixed experimental and theoretical procedure for testing capillary barriers is described. It is based on scaling concepts and hydraulic behaviour of the capillary barrier. It was applied to the case of study of a top cover at a large landfill site in the South of Europe.