Environmental Impact Assessment Ordinance (Cap. 499)
(ACE-EIA Paper 2/2002)
For advice
Environmental Impact Assessment Report for Application No. EIA-071/2001
Sheung Shui to Lok Ma Chau Spur Line
Purpose
1. This paper presents the key findings and recommendations set out in the EIA Report for the Sheung Shui to Lok Ma Chau Spur Line (the Spur Line) project, submitted under Section 6(2) of the Environmental Impact Assessment Ordinance (EIAO) as application no. EIA-071/2001. A presentation will be given by the project proponent, Kowloon-Canton Railway Corporation (KCRC) and its consultants.
Advice Sought
2. Members' views are sought on the findings and recommendations set out in the EIA Report.
Need for the Project
3. The proponent indicates that the Spur Line project is needed to relieve the congestion at Lo Wu and to serve the future Kwu Tung North New Development Area.
Description of Project
4. The EIA report on a viaduct option of this project has been the subject of an appeal considered by the EIA Appeal Board. Subsequent to the handing down of the Appeal Board's judgement on 30 July 2001, KCRC has adopted one of the alternatives mentioned by the Appeal Board and revised the Spur Line railway scheme and the construction method involving a tunnel section to avoid Long Valley.
5. The horizontal alignment of the Spur Line of 7.4km long is unchanged. The key change is the vertical alignment which will now travel through Long Valley, Kwu Tung and Chau Tung in an underground tunnel (approximately 4.3km) instead of on viaducts before it climbs to viaducts alongside and terminates at Lok Ma Chau.
6. The proposed Spur Line project is a designated project under Item A.2, Part 1 Schedule 2 of the EIA Ordinance, i.e. "a railway and its associated stations".
Specific Environmental Aspects to Highlight
Ecology
Long Valley
7. The revised tunnel option does not involve ground level works in Long Valley. The potential hydrological impact to Long Valley due to the construction and operation of the Spur Line tunnel has been assessed in the EIA report. In accordance with the findings of the hydrological assessment, the construction of tunnels underneath Long Valley will have minimal effect on the groundwater as the tunnels are mainly to be placed well clear of the aquifer. The EIA has also referred to previous local experience of tunnel works under more difficult situations yet no leakage problem has been encountered. As such, the EIA has considered that leakage of tunnels causing constant draw down of groundwater is unlikely to be a serious issue in the Long Valley section as almost the entire section of the tunnels will be constructed beneath the aquifer.
8. In addition, a comprehensive monitoring and contingency plan was formulated in the EIA report. In case there is a substantial draw down of groundwater at Long Valley, the existing AFCD's fabric-dam at the upstream of River Beas will be inflated so as to divert more flow into Long Valley. The EIA has also stated that the WSD's fabric-dam at the downstream of River Indus could be operated if necessary to flood the alluvial aquifer across Long Valley.
Lok Ma Chau
9. For the Lok Ma Chau section, the EIA confirmed that the footprint of the Lok Ma Chau station has been minimized to reduce impacts on these sensitive ecological areas while providing adequate areas for the immigration and customs facilities.
10. The anticipated loss of fishponds at Lok Ma Chau due to the Spur Line project include the following:
- direct loss of approximately 0.4ha active fishpond and 9.1 ha of inactive fishpond at Lok Ma Chau for the provision of the station complex, the viaduct columns and the Emergency Access Point; and
- direct loss of 0.1ha of inactive fishpond at Chau Tau for the provision of ventilation building.
11. To mitigate the unavoidable loss of fishponds and associated ecological impacts, the EIA report recommended the following mitigation measures:
- enhancement of 27.1 ha of existing fishponds at the southwestern side of the Lok Ma Chau Station;
- creation of 9.9 ha of reedbed and marshland areas alongside the Lok Ma Chau Station to increase habitat diversity and function as a barrier to disturbance; and
- planting of 1 ha of bamboo/tree/shrub/reedbed alongside the station areas.
12. The enhancement measures to increase the ecological value of the fishponds include enlargement of small fishponds, reprofiling of bunds to increase bird feeding opportunities, planting and management of vegetation, controlling of water levels, manipulation of fish stocking, feeding/fertilizer regime and drain down of fishponds to optimize the food availability for birds. To mitigate for the ecological impacts during the construction stage, 15 ha of fishponds will be enhanced in advance of any construction at the Lok Ma Chau station takes place.
13. With all the proposed ecological mitigation measures in place, the EIA concluded that the loss in ecological function and capacity can be adequately compensated.
Noise
Construction Noise
14. The EIA has assessed that with the use of quiet equipment, programming to reduce concurrent operation of plants and provision of 2.5-5m high temporary barriers, the construction noise impacts at the nearby sensitive receivers (NSRs) will be mitigated to within the established assessment criteria.
15. The tunnel boring activities will be carrying out continuously and thus, night-time construction is required. As tunnel boring will take place at a depth of at least 8m below ground and village houses with shallow foundations are located more than 100m away from the tunnel alignment, the night-time construction noise impact is unlikely to be insurmountable. Nevertheless, an application of the Construction Noise Permit (CNP) is required for the construction work in the restricted hours under the Noise Control Ordinance (NCO). Whether a CNP can be granted under the NCO is subject to provisions under that Ordinance.
Railway Noise
16. The NSRs at the residential development in Sheung Shui will be impacted by the railway noise during night-time operation. The EIA has recommended that an absorptive cantilevered barriers of up to 5.8m high with 3.6m inclined panel will be constructed along the railway alignment to mitigate the railway noise impacts.
Environmental Monitoring and Audit (EM&A)
17. An EM&A programme has been proposed in the EIA report, and included a detailed Implementation Schedule. The EM&A requirements, including the hydrological and ecological monitoring programme to confirm the effectiveness of the recommended measures will be enforced as Environmental Permit conditions.
Consultation
18. The EIA report is now subject to public inspection under the EIAO. KCRC has made the EIA report and the Executive Summary available for public inspection on 7 January 2002. Members will be briefed about any comments received from the public at the meeting.
January 2002
Environmental Assessment and Noise Division
Environmental Protection Department
