Harbour Area Treatment Scheme

7The Harbour Area Treatment Scheme (HATS) in Hong Kong included approximately 7.5 km of drill-and-blast tunnelling at depths of around 100 m below ground along the west coastline of Hong Kong Island. The tunnels were concrete-lined to form two large-diameter sewer conveyance pipes connecting to the Stonecutters Island Sewage Treatment Plant. The works also comprised five vertical shafts up to 130 m deep to link the existing sewage network with the new system, forming a critical component of Hong Kong’s long-term environmental and wastewater infrastructure strategy.

Andreas Tauschinger served as Leighton Asia’s Tunnel Operations Manager, responsible for managing tunnelling works under conditions of significant groundwater inflow. These challenges were effectively controlled through systematic pre-excavation grouting (PEG), ensuring safe and stable excavation. The tunnel section was successfully completed in early 2015 to the full satisfaction of Hong Kong’s Drainage Services Department, contributing to the protection of Victoria Harbour and the enhancement of the region’s environmental performance.