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2 PROJECT DESCRIPTION

2.1 Site Location

2.2 EIA Study Area

2.3 Project Requirements, Scope and Benefits

2.4 Consideration of Alternatives

2.5 Construction Methods and Engineering Requirements

2.6 Operation of the Project

2.7 Works Programme

2.8 Related Projects

2 PROJECT DESCRIPTION

2.1 Site Location

2.1.1 An existing cross harbour fresh water mains of about 1.1 km length and comprising twin 1,000 mm diameter steel submarine pipelines runs from Tsim Sha Tsui, along the west of the MTR Tsuen Wan Line to a landfall at the seafrontage north of the Wan Chai West Sewage Screening Plant, near Lung King Street. The reclamation works could potentially damage the watermains and diversion of these mains will be necessary. The total dredged volume for the construction of the cross-harbour watermain is estimated to be approximately 0.06Mm³. The location of diverted Cross-harbour water mains is shown in Figure 1.2f.

2.2 EIA Study Area

2.2.1 The following definitions of the study areas have been adopted with reference to the EIA Study Brief registered under the EIAO:

· Air Quality Impact: the assessment area should include the area within 500 m from the boundary of the Project;

· Noise Impact Assessment: the assessment area should include the area within 300 m from the boundary of the Project;

· Water Quality Impact Assessment: the assessment area should include the areas within and 300m extended beyond the boundary of the Project, plus the Victoria Harbour Water Control Zone (WCZ), the Eastern Buffer WCZ and the Western Buffer WCZ as declared under the Water Pollution Control Ordinance;

· Waste Management: the assessment will focus on areas within the boundary of the Project;

· Land Contamination: the assessment area for land contamination impact will include any potentially contaminated sites identified in this EIA;

· Landscape and Visual Impact: the area for landscape impact assessment should include all areas within 100 m extended from the boundary of the Project, while the assessment area for the visual impact assessment should be defined by the visual envelope from the Project and associated works;

· Marine Ecology: the assessment for marine ecological impact will focus on the area within the Project boundary; and

· Cultural Heritage Impact: the assessment for cultural heritage impact will focus on the area within the Project boundary.

2.3 Project Requirements, Scope and Benefits

Project Scope and Requirements

2.3.1 An existing cross harbour fresh water mains, comprising twin 1,000 mm diameter steel submarine pipelines from Tsim Sha Tsui, runs along the west of the MTR Tsuen Wan Line to a landfall at the seafrontage north of the Wan Chai West Sewage Screening Plant, near Lung King Street. As the reclamation works could potentially damage the watermains, diversion of these mains prior to construction will be necessary. It is an essential requirement by WSD that the operation of the cross harbour water mains should be maintained at all times with no interruption to the water supply.

Project Benefits

2.3.2 The Project provides opportunity to lay new cross harbour water mains to replace the existing ones, to avoid damage to the existing mains and disruption to essential water supply to Hong Kong Island.

Consequences of Not Proceeding with the Project

2.3.3 Should the existing cross harbour water mains not be reprovisioned under the Project, the existing cross harbour water mains will potentially be damaged by the reclamation works and the construction of the Trunk Road tunnel. Without the cross harbour watermains, the fresh water supply to Hong Kong Island will be seriously affected, which cannot be tolerated.

2.4 Consideration of Alternatives

2.4.1 The alternative to constructing new cross harbour watermains to reprovision the existing one is to construct a deck over structure above the existing pipelines. However, this alternative option is considered not feasible as the Trunk Road tunnel will be crossing the existing pipelines at a similar level and there will be problems for future maintenance of the pipelines below the deck structure. Construction of new cross-harbour water mains is considered a reasonable and practicable solution.

2.5 Construction Methods and Engineering Requirements

2.5.1 As the proposed twin 1,000mm submarine fresh watermains will replace the existing one, the proposed fresh watermains will be reprovisioned on a like-for-like basis.

2.5.3 To protect the submarine watermains against damage by maintenance dredging and marine operation in the harbour, cover and cushion layers similar to those for the existing submarine watermains will be provided. The cushion layer can be in materials such as armour, steel plate, etc.

2.5.4 The construction method for the submarine pipelines involves dredging for a pipe trench and laying of bedding materials, pipelines and covering materials by marine plants. The construction of the land section of the fresh watermains will follow the normal practice with excavation and installation of shoring, bedding, pipelaying, backfilling, construction of chambers, installation of valves, pressure testing and pipe sterilization.

2.6 Operation of the Project

2.6.1 Operational activities, on completion of the Project, would comprise essentially the operation of the new cross harbour watermains, which replaced the existing one running from Tsim Sha Tsui to the waterfront at the west of HKCEC.

2.7 Works Programme

2.7.1 The construction works of the Cross-harbour water mains are anticipated to commence on site in early 2009, with completion by 2010. A construction programme is presented in Appendix 2.5 for reference.

2.8 Related Projects

2.8.1 The following projects are related to the DP6:

(i) Civil Engineering and Development Department's CRIII project, comprising reclamation along the Central waterfront for transport infrastructure needs (including CWB and NIL) and basic land use requirements. A section of CWB tunnel will also be constructed under CRIII project. Construction will take place from February 2003 to September 2012.

(ii) Trade Development Council’s Atrium Link Extension project, comprising a link bridge spanning across the water channel between the Hong Kong Convention and Exhibition Centre (HKCEC) Phase I and HKCEC Extension. Construction will take place from May 2006 to March 2009.