Leachate Flow Mound Equations for Steady-State Flow Over a Landfill Geosynthetic Bottom Liner

A simple approach, using Darcy’s law, is taken to derive a set of equations to estimate the shape of the leachate flow mound over a landfill geosynthetic bottom liner. Steady-state flow conditions through a homogeneous porous media, over a sloping impervious base, are assumed. The derivation is extended to analyze the leachate flow mounding in a two-layer drainage system. The two-layer model may be particularly suited for analyzing leachate flow over a landfill geosynthetic bottom liner system that incorporates a geonet. The results of parametric analyses of the derived leachate flow mound equations and several other flow mound equations found in the literature are compared. Finally, based on the performance of the new leachate flow mound equations, recommendations are made concerning an often overlooked aspect of the leachate collection and removal system (LCRS) design.