THE ENVIRONMENT
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dredged material) will require collection and disposal each day. A Waste Disposal Plan setting out the framework for management of all waste types was published in late 1989 after extensive public consultation and endorsement by the Governor in Council. The plan specifies the waste disposal strategy for the territory and a programme for phasing out old facilities and the provision of new works and services.
During 1989, a comprehensive sewage disposal strategy was completed for the whole territory. Most of the proposed strategy involves the construction of large tunnels linking the main urban areas to treatment plants, and further tunnels leading to an undersea outfall for the treated effluent, some 30 kilometres south of the centre of the city. Ultimately this system could accommodate the sewage from the new towns of the north-east New Territories and even further afield. The treatment to be provided initially will include chemical treatment and high rate sedimentation. In June 1990, consultants began work on site investigations as a prelude to detailed design. Oceanographic surveys and mathematical modelling work commenced at the same time to help ascertain the best location for the undersea outfall.
Sewerage Master Plans
The government is preparing a series of comprehensive sewerage master plans for all sewage catchments in Hong Kong. While the sewage disposal strategy deals with how to treat and get rid of the sewage, the complementary sewerage master plans deal with how sewage is collected from the factories and households where it originates and how it is then piped to the central disposal system. The sewerage master plan for the Tolo unsewered areas was completed in June 1990. Studies of Tsuen Wan, Kwai Chung and Tsing Yi, North-west Kowloon and Port Shelter continued and new studies have already started for Central, Western and Wan Chai West on Hong Kong Island and Yuen Long and Kam Tin in the New Territories. The detailed design of new sewerage systems for East Kowloon, Hong Kong Island South and Tolo areas recommended under previously completed sewerage master plans has started.
Disposal and Treatment Facilities
Design and construction work is in progress on several municipal sewage treatment and disposal projects in the urban areas including the Shau Kei Wan screening plant and outfall, the To Kwa Wan screening plant and outfall and the North West Kowloon sewage treatment and disposal project.
Design work started early in 1990 on the East Kowloon pollution control and sewerage improvement project, which provides a major relief sewer, dry weather flow interception control structures and a pumping main from Yau Tong to the Kwun Tong screening plant. Upon completion of the project in 1993, the problem of potential flooding by sewage and discharge of polluted flows into the stormwater system through expedient connections will have been overcome.
Under the Hong Kong Island South sewerage improvement project, design work continued on an underground secondary sewage treatment works for Stanley, a screening plant at Shek O and various sewage pumping stations and sewerage systems in the area. Construction works will commence early in 1991 and should be completed by the end of 1992. The water quality along the coast of Hong Kong Island South, particularly adjacent to gazetted beaches, will improve as a result of this scheme.