An analytical method for predicting the velocity field beneath landfills

An analytical flow model is developed for use in estimating the steady-state velocity field and the head distribution beneath landfills and in aquitard-aquifer systems with a maximum of two aquifers or permeable layers. The landfills may be engineered with a single or double liner and a drainage layer (i.e., a hydraulic control layer or a secondary leachate collection system) or may be without any such engineered layers. The models are checked against a finite element model for various landfill geometries and hydrogeologic settings. Agreement between both methods is found to be excellent. The application of the technique for use in sensitivity studies performed to assist in the preliminary design of landfills is illustrated by examples.