Remediation work valued at approximately $35M was undertaken by Thiess Services at the five hectare former Allied Feeds site in Rhodes, NSW. The remediation site was established in August 2005 and the project concluded in August 2009.
Originally the location of a flour mill, the site became contaminated over a number of decades when foreshore land was reclaimed using lime and ash wastes. The wastes came from the chemical manufacturing plants that were operating on the neighbouring Lednez/Union Carbide site and consequently they contained a variety of chemical residues.
The principal contaminants of concern found on the site were dioxins, by-products of the chemical manufacturing process. The remediation work was undertaken to reduce the level of dioxins and other chemicals found in the soil.
"Directly-heated thermal desorption" (DTD) technology was used at the site to treat the contaminated soil. This method was chosen based on a detailed review of the performances of the best available technologies. DTD also met the strict emission criteria and contaminant destruction efficiencies stipulated by the project regulator, the Department of Environment, Climate Change and Water (DECCW).
190,000 tonnes of soil was excavated and thermally treated to a standard suitable for reuse on the site. The soil reuse criteria were developed to protect both human health and the environment. A Site Auditor accredited by the DECCW approved the criteria.
Meriton Apartments, the owners of the land, are currently developing it. Now that it is fully remediated, it will provide a safe location for the development private residential apartments and public open space with direct access to the Homebush Bay foreshore.