MECHANISMS OF LEAKAGE THROUGH SYNTHETIC LANDFILL LINER MATERIALS

The introduction of synthetic lining materials for leachate containmen t and the prevention of ground-water contamination was an important de velopment in landfill technology. These materials have a low hydraulic conductivity which results in minimal leachate release by bulk fluid flow (advection) provided that the barrier (and its construction) is f ree from defects. However, the effectiveness of these materials as bar riers cannot be confirmed unless contaminant release by diffusion is a lso taken into consideration. This paper reviews the mechanisms by whi ch transport through barriers occur. It highlights the role of diffusi on as a pathway for organic compounds to migrate through synthetic lin ers and indicates its importance in terms of environmental impact and landfill design.