Groundwater contamination from waste-engine oil recycling in Western Australia

The successful remediation of a contaminated site, in terms of technical and financial goals, cannot be achieved unless the hydrogeology and the nature and extent of contamination is understood in advance of the selection of a remedial strategy. The metropolitan area of Perth, Western Australia contains at least 700 contaminated sites excluding petrol stations, each of which has the potential to pollute shallow unconfined sand aquifers which supply 40% of Perth's public water supply and private irrigators. The site considered in this paper consists of an abandoned brick-clay pit, 7 m deep, filled with the by-products of a waste oil refinery and builders' rubble. The wastes below the water table contain concentrated sulphuric acid, heavy metals, PAH, BTEX, phenols and oil. Leachate from the pit has a TDS of 87 000 mg/L.