16. CONCLUSIONS AND RECOMMENDATIONS
16.1
The Sheung Shui to Lok Ma Chau Spur
Line is planned by Kowloon Canton Railway Corporation (KCRC) to relieve the
envisaged congestion at Lo Wu Boundary Crossing beyond 2007. The increasing
number of passengers using the Lo Wu crossing point has the potential to create
unacceptable crowding and present a public safety risk if not rapidly resolved.
16.2 The Spur Line is an extension to the existing East Rail system, designed to link Sheung Shui to Lok Ma Chau from where a link is created with Huanggang station and Shenzhen Metro system. A number of possible horizontal and vertical alignments were considered. Selection of the tunnels option was based on the need to meet environmental, engineering, railway operation and safety requirements as described in this EIA. Starting at Sheung Shui Station, the Spur Line track will descend on ramp and through cut and cover tunnel before entering twin bored tunnels that will be located at an average depth of -10mPD through to Chau Tau. No above ground works will be carried out within the ecologically sensitive Long Valley area. In the bored tunnel section, works include construction of the Kwu Tung station box and five EAPs. At Chau Tau the Spur Line alignment rises onto viaduct and turns north to Lok Ma Chau Boundary Crossing, before terminating on the west side of the Boundary Crossing at Lok Ma Chau Station.
16.3 The selection of a scheme based on bored tunnels beneath Long Valley removes the major ecological impacts which would arise from an above ground option. Potential impacts on the hydrology of the area have been investigated in detail in this EIA. The location of the Lok Ma Chau Station within the Wetland Conservation Area (WCA) is of particular concern from an ecological viewpoint and potential impacts have been addressed in detail in this report. Other potential environmental impacts arising from fisheries, air quality, construction and operational noise, water quality, waste, contaminated land, cultural heritage and landscape and visual impacts of the project have been evaluated and the findings are summarized below.
Hydrology
16.4 Potential hydrological impacts from construction of the tunnels through the Long Valley wetland area and due to the physical presence of the tunnels during operation have been identified and evaluated. The risk of a drop in the groundwater levels during construction has been minimized through the use of an Earth Pressure Balance Tunnel Boring Machine (EPB TBM). This machine constantly balances the external pressure with an equal pressure in the cutter face to minimize the risk of collapse of the cutting face and exclude ingress of groundwater. Surface settlement, if it occurs, is expected to be minor and will be mitigated through reinstatement. A detailed settlement and groundwater monitoring programme and contingency plans are proposed. The physical presence of the tunnel during operation was modelled using 2-D finite element analysis and showed minimal impact on groundwater levels because of the placement of the tunnel in the weathered rock phase, below the main alluvial water bearing aquifer. Groundwater level monitoring within Long Valley has also shown that tidal influences in the Rivers Beas & Sutlej are far greater than those impacts predicted from the tunnel. Through careful design and monitoring, the hydrological impacts from the tunnel under Long Valley are expected to be minimal.
Ecological Impacts and Proposed Mitigation Measures
16.5
The
proposed Spur Line alignment has been selected taking into account engineering,
operation, safety and environmental constraints. In particular the sensitivity
of Long Valley has been considered in the development of the tunnel alignment
option. A hydrological impact assessment for the construction and operation of
the tunnel below Long Valley has shown minimal impact on the wetland nature of
Long Valley, which indicates minimal impact on ecological functions in this
area. Potential ecological impacts were identified in the above ground section
of the railway from Chau Tau to the proposed Lok Ma Chau Station site. This
section passes through the Wetland Conservation Area (WCA), which is an area of
major ecological importance because of the number of globally, regionally and
locally threatened species of Conservation Importance using the fishpond
habitats. Fishpond habitats have declined in Hong Kong in recent years and are
under continuing pressure from development.
16.6
Potential
impacts on this area include direct habitat loss, primarily from the Lok Ma
Chau Station footprint, and indirect habitat loss through disturbance during
construction and operation of the railway. These impacts have been minimised
through design by routing and raising the railway onto viaduct and locating the
railway within the 100m disturbance zone of the Lok Ma Chau Boundary Crossing.
Construction of Lok Ma Chau Station will result in a direct habitat loss of
9.2ha of inactive fishponds, 7.0ha of which may be used by large waterbirds. A
further 2.6 ha fishponds on the east side of the Lok Ma Chau Boundary Crossing
will be impacted, although these fishponds are already disturbed by the
Boundary Crossing. Secondary impacts will arise from the use of an area of 37ha
of fishponds for the implementation of a compensation package for fishponds
impacted by Spur Line construction. The overall functional value of the
impacted area is therefore 46.6ha.
16.7
The
functional value of the fishpond area that will be impacted is taken to be
equal to the area i.e. a carrying capacity of 1.0. Compensation for this impact
will be achieved through the enhancement of fishponds within the compensation
area to increase this carrying capacity. The estimation of increased functional
value takes into account disturbance from the future Lok Ma Chau Station. It is
assumed that large waterbirds are excluded from the area within 100m of the
station structure, and their numbers reduced by 50% between 100m and 200m. The
compensation package comprises 22.3ha of undisturbed fishponds (that can be
increased in functional value through good management, by a factor of 2, i.e.
double, to an equivalent value of 44.6 ha) and 4.7 ha fishponds within the
reduced density zone (50% value through disturbance and doubling of functional
value through enhancement results in an equivalent functional value of 4.7 ha).
0.7 ha of fishponds to the east of Lok Ma Chau Boundary Crossing will be
reinstated. The total equivalent functional value of the compensation area
therefore equals 50 ha.
16.8
Mitigation
for disturbance to large waterbirds during the construction phase will be
achieved through early enhancement of approximately 15 ha of fishponds more
than 200m from the station construction platform and progressive enhancement of
the remaining compensation area. Carrying capacity of the early enhancement
area for target species of large waterbirds (Black-faced Spoonbill, Great
Cormorant, Great Egret and Grey Heron) will be raised during the construction
period by intensive re-stocking of ponds with fish, in addition to the long
term enhancement measures proposed. Long term habitat compensation will be
achieved through enhancement of the existing value of the fishponds in the
compensation area. Enhancement will include reprofiling of pond bunds to form
shallow feeding areas; water level management to provide conditions suitable for
target species over extended periods; and fish stocking as a feed source. Ponds
within the disturbance zone of the station will provide a stocking area and
water reservoir for management purposes.
16.9
In
addition, as part of the long term mitigation package, 4.9ha of marsh will be
formed within the compensation area, the majority forming a buffer zone to the
south of the station. Bamboo stands and mixed trees and shrubs will be planted
around the station to reduce disturbance to waterbirds using the ponds. An
additional 5ha to the east of the station will be available for reedbed
planting for effluent cleanup and additional marsh. This reedbed will also
provide ecological benefit but conservatively has not been claimed in the
assessment.
16.10
The
proposed mitigation through enhancement has been developed with consideration
of current fishpond management techniques and response of large waterbirds to
drain down events. It is
considered that these proposed compensation measures incorporate adequate
provision for uncertainties as to the efficiency of the proposals, and provide
habitat enhancement for other Species of Conservation Importance recently lost
from the area due to habitat degradation.
16.11
Management
of the ecological compensation areas including the necessary financial support
will be the responsibility of KCRC in perpetuity under the Environmental Permit
(EP) conditions. KCRC will let a contract for early enhancement and for long
term management of the ecological mitigation areas to fulfil the requirements of
the EP. The wetland team will include personnel with experience in wetland
management, to fulfil the management and maintenance requirements defined in
the Habitat Creation and Management Plan (HCMP) and the EP. The HCMP will be
regularly reviewed based on the results of the monitoring data, to optimize the
management programme for the benefit of wildlife.
16.12
Preliminary
designs for all proposed ecological compensation areas are described in the
report, and measures for construction, vegetation establishment and management
are described. The design of these mitigation measures is unique to Hong Kong
in implementing and actual commissioning of compensation areas before
construction commences, and taking into account both habitat loss and
disturbance in compensation provision. This approach will enhance the long-term
opportunities for protection of Hong Kong’s ecological resources.
16.13
Potential
impacts from the construction and operation of the footbridge on the
ecologically sensitive area of Deep Bay and its associated mudflats downstream,
will be minimised with the implementation of appropriate mitigation measures
during construction and sensitive design of the bridge to minimise sediment
turbulence. Standard avoidance and minimization mitigation measures are considered
to be adequate to eliminate residual impacts from other potential impact
sources.
Fisheries Impact
16.14
Details of the fish pond practices
undertaken within the Study Area were collected, including current aquacultural
locations, practices and resources, and related socio-economic issues, in order
to assess the impact of the Spur Line on fisheries activities. Approximately
44ha active fishponds and 48ha of inactive ponds occur within the westernmost
1 km corridor of the study area. The area of inactive fishponds has
increased considerably since initiation of the clearance procedures for the
fishponds around the proposed Lok Ma Chau station area in November 2000. An
area of approximately 9.6 ha fishponds will be permanently lost as a result of
the project, primarily under the Lok Ma Chau station complex. A further
27.1 ha fishponds will be affected through the proposed ecological
compensation measures for ecological impacts and approximately 9.9ha will be
modified as marsh and reedbed. All these impacted fishponds are currently
inactive and therefore do not represent a loss of fish production. Prior to the
clearance of these ponds in preparation for the Spur Line project, the annual
production of these 9.6ha represented between 136 and 362 tonnes fish, which is
equivalent to HK$609,100 to HK$4,114,000, depending on the type of culture and
species reared. The small area of active fishponds present on the east side of
Lok Ma Chau Boundary Crossing represents a minor loss in fish production. In
addition, mitigation measures include reinstatement of fish ponds temporarily
lost during the works, and establishment of
an ecological compensation area around Lok Ma Chau Station, which will include
fishponds managed for ecological enhancement. Fishpond management for wildlife
purposes as described in the Ecology Chapter will be the responsibility of
KCRC.
Air Quality
16.15 Potential impacts on air quality during the construction of Spur
Line were shown to be minimal due to the high moisture content of the material
requiring excavation and removal during tunnelling and formation of EAPs, the
launching and recovery shafts and the Kwu Tung Station Box. Stockpiling of
excavated material will be minimal, as there will be regular removal of tunnel
spoil that is generated at approximately 500m3/day (an average of
approximately 100 lorry loads each day). Sand fill used for the Lok Ma Chau
Station formation will be discharged into part water filled ponds, thereby
minimizing fugitive dust generation. Materials handling will generate minimum
fugitive dust provided the recommended mitigation measures are implemented.
16.16 Operationally, the new railway is expected to offer some beneficial
impacts on local air quality at Lok Ma Chau, Man Kam To and the arterial
approach roads. Intercity bus, mini bus and coach crossings at the Lok
Ma Chau and Man Kam To crossings are expected to reduce as the Spur line offers
an air-conditioned and more convenient entry into the Shenzhen Metro system.
Currently, queuing and transit of these vehicles at the major crossings on both
sides of the boundary contributes to the poor air quality around these
crossings and their approaches.
Construction
and Operational Noise
16.17 Representative noise sensitive receivers (NSRs) were selected for each of the surrounding noise sensitive landuses and buildings along the length of the Spur Line alignment and their Area Sensitivity Ratings (ASR) confirmed with EPD. Several construction activities were shown to cause a short term noise impact. Potential impacts are likely to occur in Sheung Shui as a result of the diaphragm walling works associated with the ramp and cut and cover sections. Similarly, diaphragm walling required for the entire Kwu Tung Station Box will result in noise impacts at several NSRs. Impacts identified from widening of LMC Road will also require mitigation. Use of temporary noise barriers and careful scheduling of equipment have been proposed to reduce potential construction noise impacts.
16.18 During the operation period, mitigation for potentially noisy electrical and mechanical equipment at Lok Ma Chau Station takes the form of establishing design noise limits to prevent unacceptable noise impacts. The noise levels from the operation of the Spur Line railway were modelled at each NSR, using well-established theories. The placement of the Spur Line in tunnel for the majority of the alignment is of major benefit in the reduction of airborne noise during railway operation. Noise impacts occur at relatively few NSRs along the alignment. On the short at-grade section north of Sheung Shui station, the noise source was primarily airborne wheel / rail, air conditioner noise and turnouts while on the viaduct sections of the alignment (from Chau Tau to Lok Ma Chau) structure-radiated noise also contributed to the overall noise level.
16.19 Due to the close proximity of the high rise NSRs to the railway track at Sheung Shui, predicted unmitigated noise levels exceeded the noise assessment criteria in the absence of appropriate mitigation measures.
16.20 To mitigate potential railway noise impact, the following measures are required:
• Two barriers are proposed to meet the NCO at NSRs at the Sheung Shui end, north of Sheung Shui station. One barrier will be located on the east side of the railway. A second barrier will be cantilevered and will be located on the west side of the track.
• Low Vibration Track (LVT) will be installed along the entire tunnel length between Sheung Shui and Chau Tau, except the section through Kwu Tung North NDA.
• FST will be incorporated into the section of the railway through Kwu Tung North NDA to mitigate for provisional NSRs within the railway reserve.
• Structure re-radiated noise along the viaduct and airborne noise at Sheung Shui will be mitigated by reducing train speed during the first hour of operation (6:00 to 7:00a.m.)
16.21 The combination of above measures will reduce railway noise levels at current and committed NSRs to an acceptable level.
16.22 Cumulative impacts from Spur Line and the existing East Rail were evaluated to examine the relative impact from each rail operation. The same total number of trains will be operated on the current East Rail, half of the trains simply being directed onto Spur Line. A similar total noise level will therefore occur. However, with the proposed noise barriers for mitigation of turnouts for Spur Line, the overall noise level (Spur Line and realigned ER) will be reduced compared with the current situation.
Water Quality
16.23 The Spur Line passes below several major watercourses within Long Valley and over an extensive area of fishponds in Lok Ma Chau. All watercourses in the area are within the Deep Bay Water Control Zone and discharges which may potentially enter these watercourses are therefore subject to compliance with the zero discharge policy (ZDP) adopted by EPD.
16.24 A number of construction activities have the potential to impact
water quality in watercourses identified along the alignment, and downstream
water bodies (such as Deep Bay). The bored tunnelling activity will produce a
moist spoil which requires treatment before disposal, to avoid turbid run-off
entering local watercourses. Excavation of earth, particularly in potentially
contaminated areas, may result in the release of silt and pollutants into site
run-off during wet weather conditions. Excavation activities within drained
fishponds or water courses may release pollutants into the water body, and
run-off from concreting works areas will raise the pH of local water bodies,
causing ecotoxic conditions in the presence of high levels of ammonia.
Construction of the footbridge across Shenzhen River may cause unacceptable
impacts on water quality and downstream ecology in the environmentally
sensitive area of Deep Bay, in the absence of adequate mitigation measures.
Chemical storage creates the potential for spills, and the presence of workers
will increase the potential for uncontrolled release of sewage and other
wastewaters. Mitigation of impacts associated with tunnelling require proper
treatment of tunnel spoil, including dewatering and treatment of separated
water, to avoid impacts. Mitigation of impacts on water quality requires
construction of a well designed and maintained site drainage system, both on
site and during footbridge construction, proper handling of wastewater,
especially concrete washings, appropriate storage and control of chemicals, and
provision of adequate facilities for site workers.
16.25 Operational impacts from the Spur Line railway have the potential to increase hydraulic and pollution impacts from stormwater run-off from the railway tracks and the trains, hydraulic impacts from the presence of additional piers in Shenzhen River, and pollution from sewage generated by staff and passengers at Lok Ma Chau station.
16.26 To minimize potential hydraulic impacts from the footbridge across Shenzhen River, the pier size and shape must be carefully designed. This will minimize scour and turbulence and thus minimize impacts on downstream Deep Bay waters and mudflats. One set of piers has been restricted to the shallow margins of the river clear of the main flows and marine traffic.
16.27 Potential negative impacts from metal grindings (from track grinding), oil & grease and lubricants from maintenance works, and suspended solids from the trains and station building can be effectively reduced through the implementation of good working practices during cleaning and maintenance, and incorporation of appropriate pollution control measures such as oil interceptors/sediment traps into the drainage system design.
16.28 Sewage generated by passengers and staff will be treated in an on site wastewater treatment plant with disinfection to the required standard for discharge to Deep Bay. EPD’s Zero Discharge Policy, which is designed to protect the environmentally sensitive area of Deep Bay, will be achieved through two mechanisms:
• polishing of effluent in a constructed reedbed around the Lok Ma Chau station (expected to reduce BOD5 and E.coli); and
• off-setting the pollution load to Deep Bay by treating an equivalent pollution load extracted from the adjacent San Tin Channel. An area of approximately 2ha will be used to form a constructed reedbed around the station, for reducing BOD5 and E.coli to an acceptable standard before discharge to Shenzhen River.
16.29 Establishment of the reedbed prior to the commencement of the station sewage treatment plant operation, will enable the BOD5 removal rate to be monitored and improved with suitable management of the wetland area. In the event of inadequate reedbed performance, contingency plans include tankering the effluent off-site or diverting to alternative reedbed sites to meet the ZDP.
Waste
16.30 A range of waste materials will be created from the construction and operation of Spur Line. The major source of waste material will be from the tunneling operation, from which a total of 390,000m3 will be excavated. The rate of generation will be low, at around 500m3 per day. Waste will be removed from the launching shaft, after treatment, and disposed of at a designated Government facility. Other major sources of excavated material will arise from Kwu Tung Station Box formation and EAPs. The slow speed of production makes this material unsuitable for use as fill material for Lok Ma Chau Station. Small quantities can be used to backfill cut and cover sections along the alignment. A working relationship has been established with the CED Fill Management Committee personel to identify suitable beneficial sources of imported fill material. Filling of the station area will make maximum use of suitable material from other projects, otherwise destined for public fill.
16.31 Other waste materials produced on site include concrete, wood formwork, steel poles, chemical wastes, wheel wash wastes and general refuse. Materials which can be reused should be separated from those which require disposal and appropriate facilities provided on site to maintain a clean and tidy site. Recycling should be practiced wherever possible. During operation of the Spur Line, the main wastes will be general refuse, sewage sludge and chemical wastes. A waste management strategy is described, including methods for recycling or disposal, and responsibilities for implementation and management of the waste management procedure.
Contaminated Land
16.32
A site
survey and desk top study were carried out to identify potential areas of
contaminated land along the Spur Line alignment. No areas of extensive
contamination were found, the main areas of concern being several container
storage areas, a chemical storage site, car repair yards and a leather factory
with unknown potential risks. The placement of the Spur Line in tunnel has
minimized potential impacts on contaminated sites. Excavation for the Kwu Tung
Station Box, EAPs, and the launching and recovery shafts are the main areas
likely to cause impact on potentially contaminated land. The likely contaminants
from each type of contaminated area were identified and their potential
environmental impacts described. A Contamination Action Plan (CAP) was prepared
which describes the method and type of sampling and analysis programme required
to characterize the extent of contamination during the site investigation
stage. Following approval of the CAP by EPD, and evaluation of results, the
quantity of contaminated material likely to require removal can be estimated.
At the present stage, up to 85,000 m³ of material is estimated to be
contaminated. Possible remediation methods for removal of pollutants are
outlined. However, where quantities of potentially contaminated waste are
small, disposal to landfill may be considered if the small volumes make
remediation unacceptably costly.
Cultural
Heritage
16.33 A survey of the Study Area was carried out to determine the presence of historical buildings and the potential existence of prehistoric or historic occupation on, or close to, the alignment. A number of AMO documented heritage buildings lie close to the Study Area and a catalogue of historical buildings within the area was prepared.
16.34 The tunnel option places the tunnel well below layers in which archaeological remains are likely to be present. From the surveys carried out, there is no evidence of prehistoric occupation within the Study Area as a whole or specifically within the areas to be directly impacted by structures along the proposed alignment. In addition, no cultural heritage resources will be directly impacted by the proposed alignment. The eroded lower hill slopes in the area revealed no evidence of historical archaeology or soil deposits with potential to contain such deposits, although some potential for historical archaeological material in valley bottom areas was evident, especially in Ho Sheung Heung, where Sung material was found during surveys. Indirect impacts will be minimal for all villages containing cultural heritage resources, with the exception of Ho Sheung Heung, where indirect impacts require mitigation in the form of landscaping around the proposed East EAP. In addition, during excavation of the Kwu Tung Station Box and East EAP area, a programme of testing should be carried out before excavation to confirm the absence of archaeologically deposits. A watching brief should be established during excavation to ensure a full investigation of the area is carried out and action taken where material of interest is found.
Visual and Landscape Impacts and Proposed Mitigation Measures
16.35 The decision to place the eastern section of the Spur Line between Sheung Shui and Chau Tau in tunnel has to a large extent removed many of the landscape and visual impacts predicted for the original scheme proposals. However the proposed above ground structures associated with the tunnel section including the Emergency Access Points (EAPs), Ventilation Buildings (VBs) and the tunnel portals will cause residual adverse landscape and visual impacts. However these impacts will largely be slightly adverse in significance and contained in close proximity to their location due to the enclosed nature of the existing landscape. In the future the above ground structures in the central section of the proposed alignment will be within the urban context of the proposed Kwu Tung North NDA. The predicted landscape and visual impacts for the western viaduct section and Lok Ma Chau Terminus will remain similar to those described for the original scheme proposals.
16.36 The landscape and visual character of the study area varies from the open and low lying agricultural and fishpond areas at each end of the alignment, to the more developed cottage areas and road corridor in the valley between the Tit Hang and Ki Lun Shan hills. This is reflected in the visual context with views at the ends being open and rural in character, and the views in the central section being more enclosed and screened.
16.37 The primary landscape impacts result from the viaduct section at the western end of the alignment leading to the Lok Ma Chau Terminus complex. This section of the alignment would impact small areas of agricultural land, fishponds and plantation. These areas are characterized by enclosed landscapes contiguous to the existing transport corridor with the main impacts being largely contained in the immediate vicinity of the proposals.
16.38 The proposed noise barriers north of Sheung Shui Station will be minor elements in the landscape. Being located in an area characterised by high-rise residential development and commercial premises, the scale and appearance of the proposed structure would not be out of context. The barrier will be designed to minimise impacts on visually sensitive receivers, the existing urban character and where possible existing landscape resources. In other sections of the alignment, mitigation measures such as compensatory planting, screen planting adjacent to the above ground structures and restoration of landscapes disturbed during the construction phase, such as the reinstatement of fishpond areas below the viaduct section, will be implemented. In addition to this the visual appearance of the above ground and major engineering structures would be designed to minimise as far as possible visual and landscape impacts. This includes, for example, the use of muted colours for the facades of the EAP and Ventilation Building structures which have been designed to blend into the existing landscape.
16.39 Most of the predicted impacts would not have a significant effect on the landscape resources found in the Study Area. Although a small area of the culturally important Fung Shui forest north of Lok Ma Chau Control Point would be lost, approximately 0.2 hectares, this would not have a significant impact on either the existing resource or the character of the area from a landscape perspective. Overall the proposals would lead to the loss of some 1,800 trees within the project limit and a further 250 would be transplanted. This would leave approximately 1,150 trees retained in situ. The proposed planting of some 4 hectares of compensatory tree planting as landscape mitigation within the project limit for the Spur Line would compensate for the predicated loss of woodland resulting from the scheme.
16.40 The proposed viaduct structures have been designed to be visually ‘light’ and exhibit a graceful, curving alignment at the western end of the alignment near Lok Ma Chau. The scope for landscape mitigation measures beneath the viaduct at Lok Ma Chau has been limited by the presence of fishponds and the need to reinstate them after construction is complete. However clumps of tree and shrub planting would be used, where space allows, to break up the horizontal visual emphasis of the western viaduct structure. The viaduct will fit into the general context of the infrastructure developments in the area.
16.41 The Lok Ma Chau Terminus will be set against a high-rise urban backdrop of Shenzhen and providing appropriate materials are used in the station construction, glare will not be a major source of impact. Implementation of the proposed measures including the peripheral woodland planting will minimise landscape and visual impacts.
Construction Methods, Programme and Use of New Technologies
16.42 The EIA Brief requires an assessment of “the details of the construction programme, the construction methodologies and an assessment of the extent to which the technologies to be employed are proven technologies”.
16.43 To carry out the assessment, the construction of the Spur Line has been broken down into the following major elements:
1) East Rail diversion,
2) Diversion of the Dong Jiang watermains,
3) The ramps down to the cut and cover sections of tunnel,
4) The cut and cover sections of the tunnel,
5) The bored tunnel,
6) The launching shaft, retrieval shafts, Kwu Tung station box, EAP structures, and ventilation buildings,
7) The ramp up to the viaduct,
8) The viaduct,
9) Lok Ma Chau station vehicular access
10) Lok Ma Chau station,
11) The enhancement of the fishponds at Lok Ma Chau,
12) The construction of the footbridge crossing the Shenzhen River.
Associated with the permanent works are a number of significant temporary works:
13) The jetties in the Shenzhen river for unloading materials,
14) Access roads,
15) Contractors compounds
16.44 The component methods for each of the major elements, their programme duration and a commentary on previous use of such methods are listed. The methods have been chosen with a view to overcoming the constraints imposed by ground conditions and spatial constraints.
16.45 All proposed methods have been been successfully used in railway construction in Hong Kong, or have been demonstrated to be successful in the Spur Line area – for example the techniques used for the construction of the Lok Ma Chau Boundary crossing. In other respects standard construction techniques will be employed.
Land Use and Urban Planning
16.46 An assessment of the potential impacts and benefits of the placement of the Spur Line in tunnel through the future Kwu Tung North New Development Area (NDA) was carried out with reference to information contained in the Consultation Digest for the Planning and Development Study on North East New Territories.
16.47 KTN has been planned as a rail-based new development area that meets many objectives of an environmental community in terms of cultural aspects and pollution control measures. The tunnel alignment of the Spur Line presents many benefits for the future planning of the NDA including:
• Enhanced open space provision
• Enhanced town centre
• Greater pedestrian connectivity
• More freedom in urban design
•
More
efficient use of land
• Less resumption
• More land for beneficial uses
16.48
The replacement of the previously
proposed cutting, at grade and viaduct portions of the Spur Line railway
throughout the NDA, offers new and advantageous opportunities in the overall
planning of the Kwu Tung North area. However, in taking only a wayleave for the
railway tunnels, those areas of private lands outside the eventual area of
resumption for the NDA, can be expected to become the subject of Section 16
“change of use” applications to the Town Planning Board.
Environmental Monitoring and Audit
16.49 The environmental monitoring and audit requirements during the construction phase are described in terms of the monitoring locations, periods of time, frequency and standards against which the monitoring results should be compared to determine compliance. Most of the environmental issues will be monitored during the construction period for compliance with defined environmental standards and/or mitigation measures and working practices described in the EIA report. Monitoring of groundwater levels and surface settlement during construction of the bored tunnels through Long Valley will identify the need to implement contingency plans to minimize impacts on this ecologically sensitive wetland area. Ecological monitoring at the Lok Ma Chau ecological compensation area will continue into the operational phase to determine the effectiveness of the ecological habitats which have been designed to compensate for lost ecological function.
Recommendations
16.50 This EIA Report for the Sheung Shui to Lok Ma Chau Spur Line has provided a detailed assessment of the major potential impacts which may arise from the construction and operation of the Spur Line. Avoidance of major environmental impacts has been achieved by placing the Spur Line in tunnel through the ecologically sensitive Long Valley. Placing the railway on viaduct within the Lok Ma Chau area and close to the Boundary Crossing has minimized impacts on fishponds in the Wetland Conservation Area. All environmental impacts can be mitigated through incorporation of appropriate mitigation measures as described in this report. Ecological mitigation will be implemented through early enhancement of fishponds in accordance with the management principles described in the draft Habitat Creation Management Plan (HCMP). The HCMP should be reviewed and revised as the ecological compensation programme progresses, to optimize the management regime for target species. Future projects within the Study Area and particularly those close to the ecological compensation area should take the findings and recommendations of the Spur Line into account to avoid cumulative impacts or degradation of Spur Line mitigation.
16.51 In conclusion, this assessment has demonstrated that there are no insurmountable environmental impacts as a result of the implementation of the Spur Line project.