Gas Permeability of a Compacted Soil Used in a Landfill Cover Layer

The final cover layer of municipal solid waste (MSW) landfill is considered an important matter in reducing gas flow generated by organic matter decomposition process. Landfill gas (LFG) liberation may cause a number of environmental impacts, basically due to the presence of methane and carbon dioxide in its composition. A program of air permeability tests was carried out in order to investigate the cover layer efficiency in mitigating gas percolation at Muribeca's Landfill, Recife-PE, Brazil. This paper presents experimental techniques developed to study gas flow through compacted unsaturated soils by using a flexible membrane permeameter. The results allowed to determine the air permeability parameters related to molding water content, density, particles distribution, water saturation, and matric suction.