Determination of Key Parameters in Landfill Liner Design

Compacted clay barriers are often employed as landfill liners. In Australia, the design of a clay liner is typically limited to specifying such properties as liner thickness, density, compaction, plasticity, moisture content and permeability. The main aim of such a design is to minimise the advective flow through the liner. However, overseas experience has shown that in order to design a clay barrier effective in preventing/retarding the migration of contaminants, detailed understanding of both the sorption and diffusion characteristics are essential. The importance of these parameters is demonstrated by presenting research undertaken by the Department of Civil Engineering and Surveying at the University of Newcastle into fluoride migration through kaolin and bentonite clays.