This high profile 100 hectare site was required to be transferred from Defence to another Federal Government Department and managed for conservation purposes as a biodiversity offset for the Moorebank Intermodal Terminal project.
A tight timeline and multiple human health and environmental receptors meant that OPEC had to manage and control the associated risks posed by the identified contaminants of concern such as heavy metals, petroleum hydrocarbons, asbestos and 11 hectares of the site that were contaminated with Unexploded Ordnance (UXO) from past Defence activities. There were also highly sensitive ecological receptors such as threatened ecological communities, threatened plants, threatened fauna habitats, wetlands and aquatic habitats. The site was governed by a strict “Threatened Species Permit” issued by The Department of the Environment.
Remediation strategies were devised and implemented that met with the client’s remediation goals and timeline, thus enabling the future use of the site as a biodiversity offset, meeting the requirements of the relevant stakeholders and that all identified hazards to human health and the environment were reduced to an acceptable level.
Strategies employed were often running at the same time requiring close monitoring for health and safety. UXO clearance of the 11 hectares continued throughout the project and required mechanical and manual clearance of the potentially contaminated area combined with specialist vegetation reduction and safeguarding of protected flora and fauna. Over 23,000 items were investigated during the remediation with 14 UXO items being destroyed by the Australian Defence Force (ADF).
Large volumes of Hazardous (997.32 tonnes), Restricted (2936.74 tonnes) and General solid wastes (1456.42 tonnes) were required to be removed from the site. These quantities had formed a 670m by 12m fire trail that had been formed using rifle stop butt material. On site remediation was planned for the hazardous wastes but the project timeline could not support the process time. Once the materials had been removed and the process verified, a new fire trail was built using clean imported materials.
Asbestos in soil was another major concern with over 2500 tonnes of such material being safely removed from the site along with 0.16 tonnes of asbestos fragments. Extensive materials tracking was undertaken to ensure all materials moving on and off the site could be accounted for.
Over 50,000 native species were planted in the larger cleared areas and considerable brush matting employed as part of the revegetation process that took place at the end of the project.