Impacts of leachate flow conditions on the duration of the aftercare period

The environmental impacts of deposited MSW are mainly associated with the emissionsof leachate and biogas. While biogas emissions will become negligible within decades,leachate emissions will stay on an environmental incompatible level for hundreds ofyears, calculated under simplified assumptions. The generation of leachate from MSWlandfills is determined by the waste input, the climatic conditions and the landfillconstruction and operation. In this paper the impacts of different construction (landfillcover) and operation strategies (recirculation or flushing) on the duration of landfillaftercare (in particular leachate treatment) are evaluated. Therefore a mathematical waterflow and solute transport model which has been successfully calibrated at full scalelandfills is used. The results indicate that the stabilization process of MSW landfills ismostly determined by the internal flow conditions and that operation strategies have lessimpact. Only the warranty of "homogeneous" water flow allows sufficient operation ofstrategies for accelerated stabilization ofMSW landfills.