Leachate Generation, Transport, and Control

Leachate Generation

Leachate generation is an important and necessary aspect to estimate for potential leachate leakage prevention especially into the groundwater system. Potentially leachate leakage could occur if the leachate head in the bottom liner happen to exceed 30 cm which could easily be measure by placing pressure transducer in the leachate collection well. Looking from this aspect, greater leachate generation rates would significantly increase the leachate accumulation at the bottom liners due to the downward, vertical movement of the leachate flow and mostly probably increasing the chances of leakage into the groundwater aquifer.

Leachate is produced mostly from the incoming or water input from outside primarily through rainwater infiltration apart from the water which is already present as moisture in the deposited waste stream and small fraction that could be produced from the multiple reactions inside the landfill. Usually sanitary landfills are well designed to prevent or at least minimize the water infiltration through various approaches and practices depending on the landfill owner or contractors. Therefore, overall leachate generation modeling would require information on all these aspects for overall estimation; which include the type of wastes being disposed, landfilling practice, landfill cover practices, leachate collection system and leachate recirculation (if being employed) as summarized in Table 1.