Visits and Tours

Technical Visits

Stonecutters Island Sewage Treatment Works cum Harbour Area Treatment Scheme Stage 2A Site

To improve the water quality of Victoria Harbour, the Harbour Area Treatment Scheme (HATS) commenced in the late 1990’s to provide treatment for the sewage collected from the urban areas on both sides of the harbour.  HATS Stage 1 comprised construction of the Stonecutters Island Sewage Treatment Works (SCISTW) and 23.6 km deep sewage tunnels for collecting, conveying and treating sewage collected from urban Kowloon, Kwai Tsing, Tseung Kwan O and north-eastern Hong Kong Island by chemically enhanced primary treatment (CEPT) before discharging into the western harbour.

Whilst the HATS Stage 1 system has brought substantial and widespread improvements in the general water quality of Victoria Harbour since its commissioning in 2001, HATS Stage 2A is now under construction and the project is essential to intercept the sewage flow from northern and south-western Hong Kong Island.  With the implementation of HATS, the Cross Harbour Race was resumed in 2011 after its suspension since 1978.

Highlights

SCISTW is one of the largest and compact sewage treatment works of its type in the world, occupying 10 hectares of reclaimed land which is designed to provide CEPT for an average flow of 1.7 million m³ per day.  To cater for future development, the daily treatment capacity of SCISTW is designed to be expanded to 2.4 million m³ under HATS Stage 2A.  The major elements of the upgrading works are as follows at an estimated construction cost of HK$ 7,400M:

1. Provision of a new main pumping station at SCISTW;
2. Expansion and modification of the CEPT facilities, and provision of permanent disinfection facilities at SCISTW;
3. Construction of an approx. 880m long effluent tunnel;
4. Provision of covers and deodorization facilities to the existing sedimentation tanks at SCISTW;
5. Expansion facilities at SCISTW for sludge treatment, handling, transportation and disposal; and,
6. Upgrading of sludge reception facilities at the existing West New Territories (WENT) landfill piers.

Layout of the HATS System


Aerial View of SCISTW


Construction of Sludge Dewatering Building


Construction of Sludge Cake Silos


Construction of Drop Shaft of Effluent Tunnel