1.1 In 1999, Lok Ma Chau Crossing carried an average daily flow of 18,000 vehicles (two-way). Based on the Crosslinks Further Study and the assessment of Transport Department, the total cross-boundary traffic is predicted to increase at an average rate of 9% per annum in the coming years before the opening of the Deep Bay Link and the Sheung Shui-Lok Ma Chau spur line. However, Lok Ma Chau Crossing, being situated on the preferred route of cross-boundary traffic, is envisaged to be heavily used in the longer term. While the road system of Lok Ma Chau Crossing will be improved in stages to cope with the projected traffic growth, capacity deficiency is envisaged in the future at San Tin Interchange.
1.2 According to Transport Department’s assessment, the design flow/ capacity ratios of the two approaches to San Tin Roundabout from San Tin Highway slip road and the Fanling Highway slip road will exceed the allowable capacity in 2011. As such, improvements by means of elevated roads are required to segregate the cross-boundary goods vehicles in order to relieve the traffic queues in the existing San Tin roundabout.
1.3 Apart from improving the capacity of San Tin Interchange, there is a need to provide additional northbound emergency vehicle holding space at Lok Ma Chau corridor to accommodate the excessive goods vehicle demand during traffic incidents or emergencies so as to reduce the resulting adverse traffic impact of cross-boundary traffic queues on the strategic and local road networks.
1.4 In addition, in view of the pressing need to help relieve the traffic queues in the existing San Tin Interchange, Transport Department identified the necessary widening works at westbound slip road from Fanling Highway (WSR) and southbound San Sham Road at its entry to San Tin Interchange (SSSR) should be carried out as early improvement works.
1.5 An application for an Environmental Impact Assessment (EIA) study brief was submitted by Highways Department in December 2001 with a Project Profile based on the layout proposed in the Preliminary Project Feasibility Study (PPFS) which will involve the provision of a vehicle holding area (VHA) with an emergency vehicle access (EVA), two single lane elevated roads connecting the westbound Fanling Highway and northbound San Tin Highway to the proposed VHA and a link bridge connecting the proposed VHA and the existing VHA adjacent to the Lok Ma Chau Boundary Crossing. The EIA Study Brief (No. ESB-092/2002) was issued in January 2002 for carrying out the EIA study.
1.6 In September 2002, Highways Department commissioned Maunsell Consultants Asia Ltd. to undertake an Investigation Assignment for the project. The Investigation Assignment is to review and modify the layout of the Project as defined in the PPFS report, to carry out an Environmental Impact Assessment (EIA), a Drainage Impact Assessment (DIA), a Traffic Impact Assessment (TIA), a construction risk assessment, a geotechnical assessment and ground investigations necessary for the preliminary and detailed design of the Project, and to carry out the detailed design of the WSR & SSSR early improvements works and preliminary design of the rest of the Project.
1.7 During the course of the Investigation Assignment, the layout recommended in the PPFS report has been reviewed and gone through public consultations through Yuen Long District Council and San Tin Rural Committee in May 2003. The major concerns raised during the public consultations were mainly regarding the land use and potential development of San Tin Village, and also the adverse environmental and traffic impacts caused by heavy good vehicles using the new roads. In view of the public concerns and the possible environmental impact, the road scheme has been further revised with the originally proposed VHA and link bridge deletedand a local widening of Castle Peak Road, realignment of the road connecting San Tin Highway and Castle Peak Road, construction of three at-grade roads alongside the EMDC and a new bridge connecting the existing access track to the proposed slip road added.
1.8 The revised scheme can avoid encroachment upon the Conservation Area (CA) by the originally proposed link bridge connecting the proposed VHA and existing VHA and occupation of a large area in Wetland Buffer Area (WBA) for the proposed VHA. Also, the road alignments are shifted away from San Tin Village which will induce less environment impact, especially in noise and air quality aspects. The EIA report is prepared based on the revised scheme of the Project.
1.9 The elevated slip roads are a Designated Project under Schedule 2, Part I A.8 of the Environmental Impact Assessment Ordinance (EIAO) (Cap. 499) and require an environmental permit under the EIAO for its construction and operation. The EIA Study covers the designated project elements of the Project, including the elevated slip roads, the associated at-grade slip roads and the proposed bridge connecting the existing access track to the slip road. The early improvement works including widening of westbound slip road from Fanling Highway (WSR) and southbound San Sham Road (SSSR) at its entry to San Tin Interchange were confirmed as non-designated project and is outside the scope of the EIA Study. The early improvement works would be completed by 2004/2005 to help relieve the traffic queues at the existing San Tin Interchange.
1.10 The main objective of the EIA Study is to provide information on the nature and extent of potential environmental impacts arising from the construction and operation of the proposed road scheme (hereinafter referred to as “the Project”) and related activities taking place concurrently, and to contribute to decisions on the overall environmental acceptability of the Project, after the implementation of environmental mitigation measures.
1.11 This EIA report has also reported on the need of the Project and addressed alternative alignment and design options of the slip roads in Section 2.
1.12 The Assessment Area for the purpose of this EIA Study, as specified in the Brief for the EIA Study, is presented below:
· Noise impact assessment – include all areas within 300m from the Project boundary. If the first layer of noise sensitive receivers provides acoustic shielding to those receivers further from the site, the assessment area could be reduced accordingly).
· Air quality impact assessment - the assessment area shall be a distance of 500m from the Project boundary.
· Water quality impact assessment – include all areas within 500m from the Project boundary. The area shall include but not limited to the San Tin Eastern Main Drainage Channel, the surrounding fish ponds and wetlands within the WCA and WBA, and Inner Deep Bay.
· Ecological impact assessment – the assessment area for terrestrial ecological assessment shall include all areas within 500 m distance from the site boundary of the works areas, or the area likely to be impacted by the Project. For aquatic ecology, the assessment area shall be the same as for water quality assessment.
· Fisheries impact assessment – the assessment area shall include 500 m from the limit of the works areas and the fishponds extending to the Inner Deep Bay.
· Cultural heritage impact study - all sites of cultural heritage that might be adversely affected by the impacts due to vibration associated with the construction activities of the Project.
· Landscape and visual impact assessment – the assessment area for landscape impact assessment shall include all areas within a 500 m distance from the work limit of the proposed Project, while the assessment area for the visual impact assessment shall be defined by the visual envelope of the Project.
1.13 The remainder of the report is organised as follows:
· Section 2 describes the Project and its need, works programme, and addresses alternative considerations;
· Section 3 identifies and assesses the potential noise impacts associated with the construction and operation of the Project, and recommends mitigation measures to comply with the established noise standards, wherever necessary;
· Section 4 identifies and assess the potential air quality impacts associated with the construction and operation of the Project, and recommends necessary mitigation measures;
· Section 5 identifies and assesses the potential water quality impacts associated with the construction and operation of the Project, and recommends mitigation measures to minimize the impact;
· Section 6 identifies and assesses the potential waste management implications associated with the construction of the Project and recommends appropriate waste handling, transportation and disposal practices;
· Section 7 identifies and assesses the potential ecological impact associated with the construction and operation of the Project, and recommends mitigation measures to minimize the impact;
· Section 8 identifies and assesses the potential fisheries impact associated with the construction and operation of the Project;
· Section 9 identifies and assesses the potential cultural heritage impact associated with the construction and operation of the Project;
· Section 10 identifies and assesses the potential landscape and visual impacts associated with the construction and operation of the Project;
· Section 11 identifies and assesses the potential land contamination impacts associated with the construction of the Project;
· Section 12 highlights the Environmental Monitoring and Audit (EM&A) requirements for the Project. The scope and approach are presented in detail in a stand-alone EM&A Manual;
· Section 13 concludes the findings of the EIA Study; and
· Section 14 presents the Implementation Schedules of the various environmental issues addressed in the EIA Study.