Abstract
Reduction of leachate reaching a landfill bottom is important for minimizing leakage risk.Usually, leachate reduction is achieved after final cover and adequate drainage facilities are installed at thelandfill surface. However, more active control of leachate movement inside of the landfill must be effective inorder to manage leachate. In this study, lateral water movement arising at the boundary of waste andintermediate cover layer was investigated. First, infiltration experiments were conducted under the condition ofwaste overlying intermediate cover layer. The lateral water flow in the condition was identified; that it is highlydependent on hydraulic conductivity of lower cover layer. Then, generation of capillary barrier at the boundaryof sand overlying waste layer was confirmed by experiments which were carried out for double layer of sandand waste. Result of large scale multi-layer rainfall experiments also exhibited lateral flow functioningeffectively for controlling vertical infiltration of leachate. Good agreement is confirmed between experimentaland simulation results.
