This project includes the construction of civil and associated works to cap Pond 5 at the Rio Tinto Gove site.

The Early works package included mud farming and Tailings Improvement and aimed to improve the tailing of Pond 5 with the use of a McCosker (designed and built) scroller. Works included reprofiling the Pond 5 red mud surface adjacent to Pond 4 and installation of the cap and drainage across all areas of the pond.

The Pond 5 Closure Project works include:

Decommissioning of existing monitoring instrumentation, Reshaping of Pond 5 stage area, Preparation, rolling and watering of Pond 5 cap area for liner installation, and the Installation of textured geomembrane lining on Pond 5. Excavate, form and compact perimeter drain, seepage drains, anchor trenches, contour drains, including stockpiling of excess and Unsuitable Materials, Install perforated drainage pipe, geotextile and drainage rock in seepage drains, Install geonet, geotextile and geocell in drains, including anchoring and backfill, Backfill and compact anchor trenches once lining materials are installed, Win, haul and place Pond 5 capping (drainage layer + general fill + top layer), Form and compact Pond 5 perimeter road and northern outlet drain road, including surface drains, safety berms and road capping, Install drainage inspection points and liner sampling points, Haul, and place rock buttress around edge of pond capping, Install outlets for contour drains into perimeter drain, Install flush lines, sumps and outlets for seepage drains, Reprofile Pond 5 external embankment , Install spillways, permanent culverts and drainage pipes along perimeter outlet drains, Removal of any waste products encountered in the Pond 5 cuts and burying within the residue in accordance with the waste management plan or removal from site, and stockpiling of any Unsuitable Materials and construct check dams, weirs and maintenance access areas.

Earthwork volume totals include 500000 m3 spoil, 567000 m3 local cut to fill, 660000 m3 borrow to fill (approx. 7km haul).