Construction and Quality Management of a Bentonite-Cement Slurry Containment Wall, Perth, W.A.

The Omex site, located in the eastern suburb of Bellevue in Perth Western Australia, is undergoing remediation. The site is contaminated with heavy metals, sulphuric acid, polynuclear aromatic hydrocarbons (PAH) and hydrocarbons from the past disposal of wastes from an oil-refining plant to a series of shallow clay pits. As part of the remediation program a Bentonite-Cement Slurry Containment Wall was constructed to isolate the contamination. Given the levels of contamination and the sensitive nature of the remedial works, Quality Management systems represented an important aspect of the project. It involved detailed on site supervision and testing and extensive laboratory testing of excavated materials and the containment wall slurry. This paper documents the practical aspects of the Quality Management System developed, gives details of the supervision and testing of the containment wall installation required to ensure compliance with design requirements as well as an outline of the procedures adopted for management of excavated material and surface water during construction.