Evaluating the effectiveness of landfill liners

Computer models have been used to simulate contaminant transport of an inorganic nonreactive solute through composite liners. Processes modeled include transport through defects in a liner system and advective and diffusive transport through soil in the liner. The effectiveness of three liner systems have been evaluated in terms of leakage rate, breakthrough time, and mass flux of contaminant discharged from the base of the liners. If leakage rate is used as the performance criteria, a composite liner having a geosynthetic clay liner (GCL) performed best. However, composite liners having a thicker compacted soil liner performed better in terms of contaminant transport. The thicker composite liners had longer breakthrough times and less contaminant flux from the base.