5.122. The function of submarine sewer outfalls was studied and the conclusion was that multiple port discharge would result in a favourable dilution of sewage by sea water. Based on the above findings, proposed submarine sewer outfalls in Lai Chi Kok and Sham Shui Po were designed.
5.123. Preliminary plans of sewage screening plants in Central District and Wan Chai District and the draft contract documents together with the design and drawings for Sham Shui Po District (Yee Kuk Street, Kweilin Street and Pei Ho Street) Sewerage Scheme were prepared.
Studies and Investigation
5.124. Sewage treatment problems for new developments in Sha Tin and Castle Peak and the possible effects on sanitary and drainage aspects of the proposed breakwater scheme in Cheung Sha Wan were studied.
5.125. A technical report on the requirement of the main channel width in the Aberdeen Harbour Reclamation proposal was prepared, as were two technical papers, 'Structural Design of Buried Rigid Pipes' and 'Stormwater Drainage Design in Hong Kong'.
5.126. Gauging of sewers, to establish the average daily sewage flow per capita in different types of development, was carried out.
5.127. To ascertain the characteristics of sewage, samplings and testings were undertaken. The results were also used in checking on the operation of existing septic tanks, Imhoff tanks and sewage screening plants.
5.128. Routine tests for monitoring the level of pollution in the harbour were carried out. These will provide useful information for the proposed hydrological survey of Victoria Harbour.
5.129. A laboratory vacuator was set up to experiment on sewage treatment by the 'Flotation' process. Sampling and testing of 3000 specimens of sewage and polluted water was carried out in the laboratory.
Construction
5.130. An 84-inch dia. horse shoe shaped intercepting sewer was laid in the Gin Drinkers Bay reclamation. When completed, it will direct sewage from the whole of Kwai Chung to the future sewage treatment plant on Pillar Island.
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