Design And Monitoring Of Landfill Cover Systems

Christopher B Thorley and Elisabeth J Boczek

Monitoring of the percolation through previously constructed capping layers at a former landfill at Bacton Road, Chandler was carried out to assess their performance under Brisbane climatic conditions. Comparisons of the field percolation with the results of modelling using the SoilCover finite element program were made, leading to the development of a simplified cap design. Construction of the simplified cap was carried out at a second landfill at Roghan Road, Fitzgibbon and subsequent monitoring confirmed its modelled performance agreed with the field data. Percolation rates were found to be significantly below those determined from conventional water balance models and indicate a simple single or double layer cap will perform adequately in Brisbane’s sub-tropical climate.