Queensland Alumina Limited (QAL) contracted McCosker to commence a 5-year contract to raise the QAL Red Mud Dam (RMD) Walls. The works included raising the AC and E walls on RMD2 at the QAL refinery.

AC Wall Raise, the following workscopes included:

DN1200 Rockfill Foundation and capping, Downstream toe buttress including drainage and filter layers, Embankment Raises using site won harvested tailings material, Clay cores, Screening of Borrow Material – 500,000m3, Bentonite Cut-off WallE Wall Raise, the following works consisted of:

DN1200 Rockfill Foundation and capping, Downstream buttress including drainage and filter layers, Various Embankment Raises using site won harvested material, 4m x 2m Clay core and Bentonite Cut-off WallE Wall Raise.

Additional works included the construction of the RMD#2 E Wall West embankment buttressing. This was to address the excessive pore pressure of the RMD#2 E Wall Embankment.

The construction of a 420m Downstream Buttress at RMD#2 E wall West, including Foundation preparation, Installation of sand filter, Construction of internal drainage systems and earthen fill buttress and embankment.

Installation of additional monitoring instrumentation controls and the Construction of final roads on top of the embankment