A finite layer technique for modelling complex landfill history

A semianalytical (finite layer) technique for modelling contaminant transport from a landfill for relatively complex conditions is presented. The theory allows consideration of multiple units such as secondary leachate collection systems, hydraulic control layers, or aquifers, which can be used to remove contaminant from below the landfill. The theory allows consideration of time-varying properties of the system (e.g., shutdown or failure of the primary and (or) secondary leachate collection systems after a specified period of time). It also allows consideration of complex source concentration histories with time, including the increase in concentration with time, constant source concentration for a period of time, and decrease in concentration as mass is removed from the system. The application of the technique is illustrated with an example.