GFWAust were awarded the contract to grout the foundations of the new sediment ponds EP2, EP3 and P4a. dams.

BHP Billiton Illawarra Coal Holdings Pty Ltd owns and operates the West Cliff Colliery in the Southern Coalfield. The Colliery is located on Wedderburn Road of Appin Road approximately 4km south east of Appin. The underground mine produces clean coal through the 4.5 million tonnes capacity washery with storage of over 2.5 million tonnes on site. Stage 3 Emplacement for the expansion of the washery required diversion of Brennans Creek and the construction of additional settlement ponds to store overflow during storm events from existing Emplacement Settlement Ponds.  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.