Due Diligence Contamination and Geotechnical Assessment

Description and Value of Services Provided by the Consultant

Raw Earth Environmental was engaged to undertake a due diligence contamination and geotechnical assessment following the importation of soil from an unknown source at a proposed low-density residential development site. The assessment was critical in determining the suitability of the imported material for its intended use and ensuring compliance with environmental and planning regulations.

The site is planned for a Torrens Title subdivision, creating 17 residential lots with associated infrastructure, including public roads, drainage, and landscaping.

A) Soil Contamination Investigation

A due diligence assessment was conducted to evaluate potential contamination risks associated with historical land use, specifically:

• Uncontrolled fill material potentially deposited across the site.
• Historical agricultural use, with the potential for residual pesticides, herbicides, and insecticides.

Raw Earth implemented a targeted soil investigation in accordance with the NSW EPA Sampling Design Guidelines (2022). The assessment involved:

• Advancement of 19 test pits/boreholes to a depth of up to 3.3m below ground level (bgl).
• Collection of 19 primary soil samples and 19 samples for asbestos-containing materials (ACM).
• Laboratory analysis of 21 samples for a suite of contaminants
• Inspection by a Raw Earth Licensed Asbestos Assessor (LAA) to identify any potential ACM on-site.

B) Geotechnical Investigation

• Geotechnical testing was conducted to evaluate the material's suitability for residential development.
• A 5-tonne excavator was engaged to conduct test pitting down to 3.5m bgl, as the presence of large boulders in the soil profile made drilling difficult.

The investigation findings provided the client with confidence in the site's environmental and geotechnical suitability, ensuring compliance with regulatory requirements for residential redevelopment.