Final Engineering services report _62 Lake Macdonald Drive · OPW25/0057

The site:

•     Does not contain Acid Sulfate Soil overlays.
•     Does contain Landslide Hazard, moderate to high overlays.

Geotechnical testing has been undertaken on the site and a Geotechnical Investigation Report has been prepared by
Core Consultants.

The residual soil consists mostly of sandy-clay (eastern side) and silty-clay (central and western areas). Both the silty
and sandy clay soil samples tested are non-dispersive.

The report recommends temporary batter slopes up to 3.0 m vertical height could be battered at 1V:2H in the firm
residual clay soils, and 1V:1H in the stiff (or stiffer) residual clay soils and weathered rock.

For permanent fill batters:

•     1V:3H in the firm residual soils.
•     1V:2H in the future controlled fill and stiff (or stronger) residual soils and extremely weathered materials.
•     1V:1H in the highly weathered, very low strength sandstone.

The depth of topsoil and contaminated material across the site has been interpolated from the test pit data provided
in the Geotechnical and Contaminated Land Remediation reports. This data has been used to model the surface used
to approximate the required stripping and excavation volumes that are shown on the design plans.

3.2      EROSION AND SEDIMENT CONTROL (ESC) AND ENVIRONMENTAL MANAGEMENT

In accordance with the contractual obligations and Environmental Legislation requirements, the Civil Contractor
performing the site remediation and civil earthworks are responsible for the management of site runoff.

The contractor is to ensure the capture and treatment of stormwater flows during construction activities and up to
the time the site is suitably stabilised in accordance with legislative requirements.

The contractor is to engage a Registered Professional Engineer Queensland (RPEQ) with suitable Erosion and Sediment
Control experience or Certified Professional in Erosion and Sediment Control (CPESC) to provide site ESC plans for
submission with the Construction Management Plan to Council.

Throughout construction activities, the contractor is to engage regular (to be determined by Council) CPESC
inspections and reporting.

Construction stormwater runoff is to be captured and directed to High Efficiency Sediment (HES) basins for treatment
prior to leaving the site.

Lots 1, 2 and 3 and any disturbed areas of balance Lot 100 are to be stabilized through the application of topsoil and
seeding with ongoing maintenance suitable to ensure adequate grass coverage of the site.

Further earthworks activities and ESC requirements associated with the future built form of each lot is to be
documented and approved through future Operational Works applications.




62 Lake Macdonald Drive, Cooroy – Engineering Services Report                                                         Page 3
233467 | M24-1037Rpt – Issue A – April 2025