13. CONCLUSIONS AND RECOMMENDATIONS

13.1 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 2004. The increasing number of passengers using the Lo Wu crossing point has the potential to create unacceptable crowding and present a safety risk if not adequately and rapidly resolved.

13.2 The Spur Line is an extension to the existing East Rail system. Starting at Sheung Shui Station, the Spur Line track will pass on viaduct over the existing East Rail and across the ecologically valuable Long Valley area before the track passes onto at grade and cutting sections at Kwu Tuong and Pak Shek Au. At Chau Tau, the route turns north on viaduct parallel to Lok Ma Chau Boundary Crossing, before terminating on the west side of the Boundary Crossing at Lok Ma Chau Station. The location of the Lok Ma Chau Station within the Wetland Conservation Area (WCA) is of particular concern from an ecological viewpoint. Ecology, operational train noise, visual and landscape impacts and operational water quality impacts from the Lok Ma Chau Station sewage treatment plant, are key issues in this study. Other potential environmental impacts arising from construction noise, air quality, water quality, waste, contaminated land, fisheries and cultural heritage have been evaluated and the findings are summarized below.

Construction and Operational Noise

13.3 Representative noise sensitive receivers (RNSRs) 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 at the RNSRs near Kwu Tung / Pak Shek Au Cutting, during removal of rippable material to form cutting and widening of Lok Ma Chau Road. Use of temporary noise barriers and careful scheduling of equipment have been proposed to reduce potential construction noise impacts.

13.4 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 modeled at each RNSR, using well-established theories. On the at-grade sections, the noise source was primarily airborne wheel / rail and air conditioner noise, while on the viaduct sections of the alignment structure-radiated noise also contributed to the overall noise level.

13.5 Due to the close proximity of the RNSRs to the railway track, and the relatively low Acceptable Noise Levels applicable to the rural and semi-rural setting of the Study Area, predicted unmitigated noise levels exceeded the noise assessment criteria in the absence of appropriate mitigation measures.

13.6 To mitigate potential railway noise impact, the following measures have been found necessary to reduce noise to acceptable levels:

• Structure re-radiated noise will be mitigated by installing Floating Slab Track (FST) on viaduct at the eastern end of the alignment.

• Low Vibration Track (LVT) will be installed on the western viaduct between Chau Tau and Lok Ma Chau Station.

• A parapet extending to 1.2 m above the safety walkway will be installed as part of the standard viaduct design for all viaduct sections and on embankment and cutting sections of the alignment. In the embankment and cutting sections, this forms a single plenum system for reduction of air borne noise.

• North of Tsung Pak Long, on the uptrack side, a noise barrier, approximately 200 m long, and 2 m tall is proposed.

• A full enclosure is proposed to cover the points and crossings north of the existing Sheung Shui Station.

• During the morning traffic peak at 0600-0700, when the noise criteria are most stringent, six skirted trains will be operated in each direction. Together with the standard walkway plenum, this will form a multi-plenum system to reduce air borne noise along all sections of the viaduct. Consideration is being given to the provision of additional noise mitigation at key locations, which would allow operation of unskirted East Rail trains during the critical 0600-0700 period.

13.7 The combination of above measures will reduce railway noise levels at current and committed NSRs to an acceptable level.

13.8 In the absence of a defined layout for Kwu Tung SGA, noise levels have been calculated at distances indicated by the Consultants of the Planning Department and Territory Development Department. Mitigation may be required for those NSRs close to the railway reserve, in the form of reduced train speed or additional barrier/enclosure.

13.9 Cumulative impacts from Spur Line and the existing East Rail were evaluated to examine the relative impact from each rail operation. The existing East Rail operation has a significantly higher noise level (more than 10 dB(a) higher) than that arising from Spur Line operation. Mitigation which has been incorporated into the Spur Line design to minimize the impact from Spur Line on cumulative noise levels, also has a positive effect of reducing noise levels from the existing East Rail operation.

Ecological Impacts and Proposed Mitigation Measures

13.10 Due to constraints of engineering, operation and safety, the route of the proposed Spur Line will cross the low-lying wet agricultural habitats of Long Valley and the fishponds around San Tin / Lok Ma Chau. These areas are of major ecological importance because they support a diverse range of flora and fauna, including a number of globally, regionally and locally threatened bird Species of Conservation Importance. Such wetland habitats have declined rapidly in Hong Kong in recent years and are under continuing development pressure.

• Potentially high impacts may occur as a result of disturbance and the loss of fishponds (mainly resulting from the station complex) within the Wetland Conservation Area near Lok Ma Chau.

• Moderate impacts may occur from disturbance and some loss of agricultural habitats and marshlands in Long Valley.

• Adverse effects on habitats and species in other areas are minimal and can be readily mitigated.

13.11 Direct habitat loss and disturbance impacts resulting from Lok Ma Chau Station amount to 28.5 ha. These are to be compensated by enhancement of fishponds within the Wetland Conservation Area west of the station complex. It is predicted that an area of approximately 28.5 ha of fishponds, when managed to increase their present carrying capacity, would eliminate residual impacts from the Spur Line operation in the Lok Ma Chau station area for most Species of Conservation Importance. An additional 6.5 ha of reedbed and marsh (comprising 3.5 ha marsh, 2.0 ha of reedbed for effluent polishing and 1.0 ha bamboo / reedbed for screening) will provide habitat for small fauna, a wastewater polishing facility, and screening of the station. It is highly recommended that the western fishpond mitigation area beyond 500 m from the station works area is established concurrently with the start of construction work on Lok Ma Chau station. Mitigation may involve creation of shallow feeding habitats through management of water levels. It is considered that these proposed compensation measures incorporate 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.

13.12 In Long Valley, 1.7 ha of wetland habitat will be lost as a result of direct loss and disturbance impacts from the operating railway. Many Species of Conservation Importance will be compensated through creation of wetland habitat below the viaduct (approximately 2.4 ha). Disturbance-sensitive species will be compensated during the construction period, through the creation of a temporary marsh (1.81.3 ha) to the west of Long Valley. It is highly recommended that this temporary mitigation be established prior to the start of construction to create an immediate and viable refuge to minimize impacts during the construction phase. In addition, contractor’s access will be restricted to minimize the impact to ecologically sensitive areas. In the long term, these sensitive species will be compensated through the creation of additional marsh habitat by further enhancement of meanders alongside the River Beas Channel. Discussions with the Project Proponent of the Main Drainage Channel Works have enabled the design of the meanders for ecological compensation to be achieved to their optimum extent. Including this meander area of 1.4 ha, a total ecological mitigation area of approximately 5.65.1 ha will be implemented in Long Valley. These compensation measures will eliminate all residual impacts resulting from habitat loss and disturbance from this Project, for all Species of Conservation Importance in the Long Valley area.

13.13 Short-term management of the ecological compensation areas will be arranged between KCRC and a specialist contractor. Responsibility for the long-term management of the ecological habitat compensation areas will be handed over to the HKSAR Wetland Trustwetland management organisation, which is in the process of being established. The trustees wetland management organisation will assign a management agent with experience in wetland management, to fulfil the management and maintenance requirements defined in the Habitat Creation and Management Plan and the Environmental Permit. Financial support of the wetland compensation area will be through a single lump sum donation by KCRC, which the trustees will invest to cover the recurrent costs of the wetland management.

13.14 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 in Hong Kong in providing 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.

13.15 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.

Visual and Landscape Impacts and Proposed Mitigation Measures

13.16 The landscape and visual character of the site and 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.

13.17 The primary landscape impacts would result from disturbance to vegetation, agricultural areas and fishponds, together with the introduction of a major infrastructure element, particularly the viaduct section, into the landscape. The main thrust of the proposed mitigation proposals is to design a visually light weight viaduct structure, which exhibits a graceful curving alignment through Long Valley. The design allows views beneath the structure, thus minimising the impacts. The western section of the proposed alignment traverses an area largely characterised by enclosed landscapes where the main impacts of the proposed scheme would be limited to its immediate vicinity.

13.18 The proposed noise enclosure and associated barriers north of Sheung Shui Station form a significant element in the landscape. However, being in an area characterised by high rise residential development and commercial premises, these impacts are minimized. The enclosure should be designed to minimise impacts on visually sensitive receivers and landscape elements. In other sections of the alignment, mitigation measures such as compensatory planting, re-instatement of fishpond areas and design of the viaduct and noise enclosure to integrate with the local landscape character would result in minimal residual impacts.

13.19 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 100 square metres, 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 1894 trees within the project limit and a further 119 would be transplanted. The proposed planting of some 12 hectares of woodland as landscape mitigation within the project limit for the Spur Line would compensate for any loss of woodland resulting from the scheme. This equates to approximately 4300 trees in the proposed mitigation planting areas.

13.20 The mitigation measures have been designed to integrate the proposals into the existing landscape of fishponds, agricultural land, open storage and cottage areas, and the future landscape represented by the Kwu Tung North SGA. In order to achieve this landscape ‘fit’ into the future SGA landscape the planting of woodland was considered a more practicable mitigation solution than the reprovisioning of other landscape resources which would no longer be characteristic of the rail corridor.

13.21 The proposed viaduct structures have been designed to be visually ‘light’ and exhibit a graceful, curving alignment in Long Valley and at the western end of the alignment near Lok Ma Chau. The scope for landscape mitigation measures for the eastern section of viaduct have been limited by ecological requirements, and at the western end by the existing fishpond areas. 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. Also the existing fishponds would be restored below the viaduct. The viaduct would fit into the general context of the infrastructure developments in the area.

13.22 The station would 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 will minimise landscape and visual impacts.

13.1The landscape and visual character of the site and 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.

13.1The primary landscape impacts would result from disturbance to vegetation, agricultural areas and fishponds, together with the introduction of a major infrastructure element, particularly the viaduct section, into the landscape. The main thrust of the proposed mitigation proposals is to design a visually light weight viaduct structure, which exhibits a graceful curving alignment through Long Valley. The design allows views beneath the structure, thus minimising the impacts. The western section of the proposed alignment traverses an area largely characterised by enclosed landscapes where the main impacts of the proposed scheme would be limited to its immediate vicinity.

13.1The proposed noise enclosure and associated barriers north of Sheung Shui Station form a significant element in the landscape. However, being in an area characterised by high rise residential development and commercial premises, these impacts are minimized. The enclosure should be designed to minimise impacts on visually sensitive receivers and landscape elements. In other sections of the alignment, mitigation measures such as compensatory planting, re-instatement of fishpond areas and design of the viaduct and noise enclosure to integrate with the local landscape character would result in minimal residual impacts.

13.1The Spur Line will have a negligible impact on designated planning zones within the Study Area. Most of the affected area comprises agricultural land (where specific ecological mitigation is proposed), and smaller losses would occur in areas designated as Industrial (Group D), Open storage, Open Space and Greenbelt.

13.1The proposed Spur Line would not directly impact the proposed Kwu Tung North SGA, indeed it supports the SGA as a ‘rail based development’. The proposed rail corridor would allow additional landscape mitigation measures, screening it in low level views from the proposed residential development to the north and south.

13.1The mitigation measures along the viaduct in the River Beas plain are limited due to the requirement for ecological wetland mitigation in this area. However, the use of bamboo planting will break up the linear form of the viaduct and reduce its visual intrusion. The use of extensive screen planting and consideration of the noise barrier design to be visually unobtrusive will alleviate visual impacts in the central section. At the western end there is limited opportunity for screen planting, except at Chau Tau, as the fishponds will be reinstated below the viaduct. The viaduct will fit into the general context of the infrastructure developments in the area. The station is set against the high-rise urban backdrop of Shenzhen and, providing appropriate materials are used in station construction, glare will not be a major source of impact. Implementation of these mitigation measures will minimise visual and landscape impacts.

Water Quality

13.23 The Spur Line crosses several major watercourses within Long Valley and 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 the zero discharge policy (ZDP).

13.24 A number of construction activities have the potential to impact water quality in water courses identified along the alignment, and downstream water bodies (such as Deep Bay). 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 identified impacts 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.

13.25 Operational impacts from the Spur Line railway involve hydraulic and pollution impacts from stormwater run-off from the railway tracks and the trains, the presence of additional piers in Shenzhen River, and pollution from sewage generated by staff and passengers at Lok Ma Chau station.

13.26 The footbridge across Shenzhen River is currently in design stage. Pier size and shape should be optimized to minimize hydraulic impacts and turbulence and thus minimize impacts on downstream Deep Bay waters and mudflats.

13.27 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.

13.28 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. The 2ha constructed reedbed around the station will be used for reducing BOD₅ and E.coli to an acceptable standard before discharge to Shenzhen River.

13.29 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.

Air Quality

13.30 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. Site formation and hard material removal from Pak Shek Au cutting will generate minimum fugitive dust provided the recommended mitigation measure are implemented.

Waste

13.31 A range of waste materials will be created from the construction and operation of Spur Line. Construction wastes include excavated material (which may be unsuitable for future use, or reusable elsewhere on the site), 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

13.32 A site survey and desk top study was 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 likely contaminants from each type of contaminated area were identified and their potential environmental impacts described. A Contamination Assessment Plan (CAP) was prepared which described the method and type of sampling and analysis programme which would be 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 56,000 m³ of material is estimated to be contaminated. Possible remediation methods for removal of pollutants are outlined. However, it is expected that the quantities at many locations may be small enough to consider disposal to landfill.where quantities of potentially contaminated waste are small, disposal to landfill may be considered if the small volumes make remediation unacceptably costly.

Fisheries Impact

13.33 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 74ha active fish ponds and 12ha of inactive ponds occur within the westernmost 1 km corridor of the study area. 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, and a further 28.5 ha active ponds will be affected through the proposed ecological compensation measures for ecological impacts. Total loss of the 9.6 ha fishponds represents a loss of annual income to the aquaculturists in the range of 136 to 362 tonnes fish which is equivalent to HK$816,000 to HK$4,380,200, depending on the type of culture and species reared. Final details of the ecological compensation habitats will be prepared in the detailed design stage. The area proposed for ecological compensation is currently not licenced for fishfarming activities and therefore potential impacts cannot be specified. Mitigation measures for habitat loss and disturbance 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 will be the responsibility of the Wetland TrustManagement Organisation, to which KCRC will transfer the wetland compensation areas, together with a lump sum which will be invested by the trustees to cover management costs.

Cultural Heritage

13.34 A survey of the Study Area was carried out to determine the presence of historical buildings and the potential existence of prehistoric 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.

13.35 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 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 survey. 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 retention and expansion of the existing woodland buffer zone. In addition, during excavations, the area south of Ho Sheung Heung should be monitored to confirm the absence of archaeologically important deposits. No other mitigation is required for potential impacts on archaeological resources.

Environmental Monitoring and Audit

13.36 The environmental monitoring and audit requirements during the construction phase are described in each chapter 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. Ecological monitoring 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

13.37 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. All environmental impacts can be mitigated through incorporation of appropriate mitigation measures. Details of habitat creation and management have been described in the report. These requirements need to be expanded into a full Habitat Management Plan during detailed design to enable full compensation to be successfully implemented. Other projects which are existing or planned in the Spur Line area should take into account the findings and recommendation of the Spur Line in the development of mitigation measures for reduction of identified impacts.

13.38 In conclusion, this assessment has demonstrated that there are no insurmountable environmental impacts as a result of the implementation of the Spur Line project.