Abigroup Contractors were appointed by BHP to construct haul roads, clean water drains, and new sediment ponds EP2, EP3 and P4a. GFWAust were awarded the contract to grout the foundations of the dams. Grouting was carried out from the bottom of a 2m deep cut off trench.

The rock beneath the alluvium consisted of soft weathered sandstone with open joints. Water testing showed some highly permeable zones where grouting was required to the tertiary level. Grouting was carried out using normal GP cements with no additives.