Former Thebarton Depot Remediation

McMahon Services were contracted by SA Water to undertake the decommissioning and remediation of the land, formerly known as the SA Water Thebarton Depot, serving as a depot and office space since 1879. The remediation works preceded the development of the site into an 'Urban Forest'.

The site remediation works were awarded to McMahon Services, after all existing buildings were demolished by our dedicated demolition team on a previous contract.

Works included:

• Palm tree removal and relocation
• Consolidation of existing stockpiles remaining on site after completion of the demolition contract
• Separation and screening of soils for reuse
• Excavation of two repositories, 22,000m³ and 8,000m³ respectively to stockpile
• Staged excavation of contaminated material and backfill of repository in five zones, varying in contamination levels
• Existing materials on-site including gravel, rubble, concrete and brick were crushed and mixed with soil and placed in the repository 
• Installation of RC Pipe, box culvert and 230m of swale complete gabion weirs leading to two eco-seal lined retention basins
• Latent service trenches were discovered during the works, requiring detailed excavation of contaminated material
• Construction of rubble walking trials within the proposed parklands
• Landscaping works including top soiling to repository mounds and tree drip zones, and gabion seating structures

Unique Processes

Our surveyors worked closely with plant operators to achieve the required levels on-site. A Landplane was fitted with a GPS setup to provide real time levels and comparisons to design surfaces. This was particularly helpful due to the undulating nature of the site.

Environmental Management

The site was in close proximity to a local school, busy intersection, local businesses and residents, therefore a strong emphasis was placed on environmental management. With over 1200 truck movements off-site, the goal was to minimise drag-out and dust inconveniences to the surrounding community and traffic flows.

Preservation of Trees and Vegetation

Two existing palm trees were relocated as part of the works. Exclusion zones were installed around retained trees and special care was taken to ensure stored materials, vehicles, equipment and rubbish was kept away from bunted areas.