Geotechnical and Hydrological Investigation

⁠⁠⁠DEM are investigating integrating renewable technology (solar PV and batteries) into 4 diesel fired power stations, across 4 sites - Oak Valley, Yalata, Pipalyatjara, Oodnadatta.

Before works can begin, a Geotechnical and Hydrological Investigation will need to be completed at each of the four sites. The purpose of the investigation is to understand the ground condition prior to the design and construction of the solar panel foundations.

Based on the findings of the Geotechnical Investigation, contractors will have an indication of the sub-surface conditions and its aggressivity towards concrete and steel. The contamination report included in the investigation will also highlight any ecological or human health risks.

As part of the Geotechnical Investigation, a topographic survey will be completed for each site. The topographic survey will highlight the most appropriate location for the Solar PV, existing structures that need to be demolished, and the extent of civil works.

The hydrological survey will provide findings and recommendations regarding surface run-off. Surface-run will need to be considered before solar array placement.

The Geotechnical and Hydrological Investigation will include but not limited to the following:

• A survey of the area proposed, to be delivered in CAD format, this would generally show things like contours, buildings/structures (if any), roads etc.
• Dial before you dig request for underground services.
• Excavation of 10 x test pits.
• Conduct 10 x Dynamic Cone Penetrometer Test at the nominated test pit locations to a depth of 1.5m.
• Collect 3 small disturbed samples for Concrete and Steel Aggressivity testing.
• The survey also to note any water courses that may directly affect the proposed installation (essentially the lay of the land).

Deliverables will include but are not limited to:

• A hardcopy PDF plan of the topographic survey.
• An electronic file in DWG format of the topographic survey.
• Geotechnical and Hydrological Investigation including conclusion and recommendations.
• Weekly progress report.