Edmondson Park Sewage Treatment Plant Remediation

The Edmondson Park Sewage Treatment Plant project involved the remediation and civil works at a 2-hectare site that was part of the former Ingleburn Army Camp. Located approximately 40 kilometres southwest of Sydney CBD, the site included a redundant sewage treatment plant and two oxidation ponds that required decommissioning and remediation. DECC was engaged as the Principal Contractor to manage the complex tasks of hazardous material removal, environmental management, and the construction of a containment cell for contaminated soils. The project aimed to transform the site into a safe, open space suitable for public use.

Demolition of Sewage Treatment Plant (STP): DECC was responsible for the safe demolition of the STP, which included the removal of asbestos and other hazardous materials. The demolition process involved the careful dismantling of concrete structures, tanks, and associated infrastructure, ensuring that all hazardous materials were safely handled and disposed of in accordance with environmental regulations.

Hazardous Materials Removal: The project involved the relocation of 25,000m³ of asbestos-contaminated material (ACM) from various stockpiles to a designated set-down area adjacent to the STP site. DECC utilised specialised equipment and procedures to safely manage and transport the contaminated materials, minimising the risk to workers and the surrounding environment.

Containment Cell Construction: DECC excavated a containment cell at the former STP site, designed to hold 20,000m³ of contaminated material. The excavation process included the removal of VENM (Virgin Excavated Natural Material) resulting from the cell's construction, which was transported to an approved location within a 1-kilometer radius. The containment cell was filled and compacted with ACM, followed by the installation of a marker layer, capping layer, and revegetation to secure the contaminated soils.

Remediation of Oxidation Ponds: The project included the dewatering and remediation of the oxidation ponds, which involved treating the water and addressing any remaining contaminants. DECC worked closely with environmental consultants to ensure that the remediation activities met all regulatory requirements, making the site suitable for future public use.

Civil Earthworks: DECC undertook significant civil earthworks, the construction of haulage roads within the site, clearing and grubbing, and site mulching. The completion of these earthworks was essential in preparing the site for its final use as an open public space.