Numerical analysis and modelling of gas flow within MSW landfill has the potential to significantly enhance the efficiency of design and performance of operation for landfill gas extraction and utilization projects. Available models implement a simple theoretical basis and treat the landfilled waste fill purely as a porous medium with the conservation of mass inherently assumed and the ongoing gas generation thus ignored. The research described in this work was intended to evaluate the error introduced into estimates of the intrinsic permeability of waste from landfill gas pumping tests if...