The Engineered Landfill occupies a footprint of approximately 82 ha, constructed on a designated site of approximately one square kilometer in extent. The landfill is lined in order to mitigate the risk of groundwater contamination and constructed in stages to receive waste from the HIA. Waste material was disposed of in the Engineered Landfill and finally capped and the site rehabilitated.
Its final appearance is similar to the existing area, with moderately sloping sides to the fill. A factor that was very important in the design of the landfill site is that the high water table within the area varies between 5m and 0.5m below the natural ground level. The design of the final cell formation and liner system considers the importance of the existing groundwater, its current unpolluted state as well as the high water table.
The landfill basin is shaped so as to provide minimum falls for leachate collection and disposal. The basin has been divided into 16 adjacent cells, 200.0 m x 225.0 m which fall to a central low point. As a result of the high water table the construction of the basin floor required approximately 566,000m3 of imported fill material, which included a 150 mm sand leveling layer to provide protection of the geo-membrane liner.