The Hong Kong Drainage Services Department (DSD) awarded a HKD 680M contract for an 8.5m internal diameter, 880m long tunnel as part of the Harbour Area Treatment Scheme (HATS) 2A sewer project project.
Chan Chi-Chiu, director of drainage services for DSD said, “The contract, comprising mainly the 880m long effluent tunnel and also disinfection facilities at Stonecutters Island, is scheduled for completion in early 2015. The tunnel will serve to convey the treated effluent from the Stonecutters Island Sewage Treatment Works (SCISTW) to an existing outfall drop shaft and provide sufficient retention time for disinfection.
He added, “The effluent tunnel will be constructed in a rock layer at a depth of 90m such that it would not constrain the development potential of the land above the effluent tunnel. Drill and blast will be used as it is a more reliable construction method at such depth.”
