Harbour Area Treatment Scheme Stage 2A (DC/2009/05 – Interconnection Tunnel and Diaphragm Wall for Main Pumping Station at SCISTW)

the major sewerage infrastructure project in Hong Kong to improve the water quality of Victoria Harbour. This contract is to construct a diaphragm wall and foundation of a new main pumping station and an interconnection tunnel at Stonecutters Island Sewage Treatment Works (SCISTW). This new underground pumping station has an internal diameter of 55 metres and a depth of more than 40 metres, and a four-metre diameter interconnection tunnel about 30m deep and 260m long for connecting the new and the existing main pumping stations at SCISTW. Cementaid Caltite concrete was specified and used in the diaphragm wall and cap for the thickness varies from 800mm to 1000mm as a full waterproof and corrosion proof tanking system.