A large fault - a fracture in the rock resulting from earth movement - was detected on the upper portion of the exposed face, which could pose a risk to mining operations below. Consequently, approximately 40 million tons of material has to be removed from the wall to deal with the safety issue and to permit access to additional ore. The biggest challenge thus far has been HJO's ability to work within the blasting constraints and produce material that is sufficiently fractured and heaved to permit efficient excavation operations. Furthermore, different rock varieties have reacted differently to the drill and blast designs. By adjusting drilling patterns, powder factors and drill hole blasting sequence, the team has been able to achieve more efficient excavation operations.