Reliability Based Approach for the Prediction of Leachate Head in MSW Landfills

Abstract

The paper presents the reliability-based approach to assess the performance of landfill considering uncertainties associated with the hydraulic properties of various components of the system. A model domain having final cover system and municipal solid waste (MSW) layer is considered as an integrated system for the analysis. Water balance is computed using the Hydrologic Evaluation of Landfill Performance (HELP) model to construct response surfaces for the reliability analysis. The probability of accumulation of leachate head \(({{h}_{ac}})\) at the bottom of the MSW layer above an allowable head \(({{h}_{al}})\) is considered as the criterion for reliability estimates in this study. The results of the analysis are discussed in terms of the reliability index, \(\beta\). The impact of variations in (a) hydraulic characteristics of the various layers (b) defects and placement conditions of geomembrane (GM) on the system performance have been studied. The results reveal that the hydraulic conductivity of compacted clay layer (CCL) of the cover component along with the porosity and saturated hydraulic conductivity of MSW layer are the significant parameters, which influence the reliability. Further, impact of model uncertainty and parametric analysis of significant variables are conducted and the results are discussed.