2.        Project Description

 

2.1.       The proposed works includes a new sewage collection system comprising gravity sewers, pumping stations and rising mains to collect and transfer the sewage generated from the Sok Kwu Wan and the surrounding areas to a new sewage treatment works (STW).  The sewage would receive secondary treatment with nitrogen removal and disinfection prior to disposal through a submarine outfall to the entrance to the Picnic Bay.  The scope of this Project includes the following:

 

·        Construction of approximately 1.4 km of gravity sewers;

·        trench excavation for installation of underground sewer pipes along Chung Mei Village, Sok Kwu Wan Village and Mo Tat Road;

·        modification of the existing combined stormwater system to separate drainage and sewerage systems;

·        construction of three new sewage pumping stations, P1a, P1b and P2, with installed capacities (ADWF) of approximately 353 m³/day, 508 m³/day and 879 m³/day, respectively;

·        construction of approximately 1.4 km rising main;

·        construction of a full secondary level sewage treatment works (STW) with nitrogen removal and UV disinfection unit with an installed capacity (ADWF) of 940 m³/day;

·        construction of a submarine effluent outfall of approximately 765 m.

 

2.2.       Figure 2.1 illustrates the layout plan of the proposed sewerage works.  Based on the preliminary construction programme, the construction of the Project was scheduled to commence in December 2004 and for completion in August 2007.  Since at this early stage of the Project there are uncertainties over the way that individual contractors would programme elements of the work, the programme has adopted a worst case scenario and assumed that certain activities would be carried out concurrently.