In 2006, Pump Systems Ltd supplied two Rotamix process mixing systems for an upgrade project at West Camden WWTP in Sydney, Australia. The mixing systems were designed to mix two identical 10 metre diameter flow balancing tanks containing undigested Thickened Waste Activated Sludge (TWAS). Innovative through-the-wall style Rotamix nozzles were used to eliminate the need for internal pipe work and to provide higher mixing efficiency over a range of levels.