Chapter Title Page
This EIA Report has provided an assessment of the potential environmental impacts associated with the construction and operation of the proposed SIL(E), based on the preliminary engineering design information available at this stage.
The assessment has been conducted, in accordance with the EIA Study Brief (No. ESB–181/2008) under the Environmental Impact Assessment Ordinance (EIAO) for the Project, covering the following environmental issues:
¡ Noise Impact
¡ Ecology Impact
¡ Water Quality Impact
¡ Landscape and Visual Impact
¡ Hazard to Life
¡ Waste Management Implication
¡ Land Contamination
¡ Air Quality Impact
¡ Cultural Heritage Impact
The findings of this EIA study have determined the likely nature and extent of environmental impacts predicted to arise from the construction and operation of the Project. During the EIA process, environmental control measures have been identified and incorporated into the planning and design of the proposed SIL(E), to ensure compliance with environmental legislation and standards during both the construction and operation phases. The implementation schedule detailing the recommended mitigation measures are presented in Section 14.
The EIA study for the proposed SIL(E) has predicted that the Project, with the implementation of the mitigation measures, would be environmentally acceptable with no adverse residual impacts on the population and environmentally sensitive resources. The environmental outcomes/benefits that have accrued from the environmental considerations and analysis during the EIA process and the implementation of environmental control measures of the Project are summarised in the following section. Environmental monitoring and audit requirements have been recommended, where necessary, to check on project compliance of environmental legislation and standards.
13.2 Summary of Environmental Outcomes, Benefits and Mitigation Measures
The Project comprises the following elements:
¡ the underground railway stations and railway facilities at South Horizons, Lei Tung and Admiralty, and the associated station entrances and ventilation shafts;
¡ the
above-ground railway stations and railway facilities at Wong Chuk Hang and
¡ the at-grade railway depot at Wong Chuk Hang and associated property enabling works;
¡ an
approximately 1.6 kilometre long underground mined/ drill and blast/ cut and
cover railway tunnel connecting the proposed South Horizons Station and the
tunnel portal near
¡ an approximately 2.0 kilometre long viaduct connecting the proposed tunnel at Lei Tung and the box structure/ tunnel portal near Nam Fung Road;
¡ an approximately 3.3 kilometre long underground mined/ drill and blast railway tunnel connecting the viaduct/ box structure at Wong Chuk Hang and the proposed Admiralty Station;
¡ an approximately 1.0 kilometre long underground mined/ drill and blast railway service tunnel connecting the existing Island Line railway tunnel;
¡ an
electrical and mechanical plant ventilation building at
¡ an
electrical and mechanical plant ventilation building at
¡ an electrical and mechanical plant ventilation building with associated access adit at Lee Wing Street, Ap Lei Chau; and
¡ SCL(NSL) Admiralty Station enabling works at Admiralty, integrating with SIL(E).
Overnight storage of explosives is needed for the construction of the underground railway facilities. A temporary project specific magazine is proposed at an abandoned site at Chung Hom Shan.
The excavated materials arising from the tunnel construction
for SIL(E) would reach ground level via four mucking out points at
13.2.2 Environmental Benefits of the Project
The proposed SIL(E) will provide a fast, convenient, environmentally friendly, and reliable mode of public transport between South Horizons and the central business district of Hong Kong, as well as for cross harbour trips via the interchange with the existing railway network at Admiralty Station.
All the travelling public, whether using the railway or other mode of transportation, will benefit either from the speedy service provided by the railway, or from the less congested road network and living quality at large.
There will not be direct emission of air pollutants from operation of the trains as they are electric powered. Reduced road traffic and congestion will also lead to improvements in local air quality.
Development of the Southern District has long been constrained by the lack of a reliable mass transportation system. Operation of the SIL(E) will remove this constraint and serve as a catalyst to trigger renewal of older districts in the Southern District in the long term.
13.2.3 Environmentally Friendly Designs Recommended and Problems Avoid
All
Given the deep underground tunnel, ground-borne train noise impacts would be minor and could be alleviated to acceptable levels through the use of vibration mitigating trackform.
Barges are to be employed for transporting majority of the
surplus C&D material from the barging points at Lee Nam Road Sitting Out
Area,
An enclosed conveyor belt system is proposed for conveying the excavated material from the construction shaft down to the barging point at Lee Nam Road Sitting Out Area. This would reduce impacts to the environment due to haulage.
13.2.4 Population and Environmentally Sensitive Areas Protected
With the adoption of
environmentally design mentioned above, major environmentally sensitive receivers
protected would include Old and Valuable Tree (LCSD S/8) within the
proposed works site along
Potential construction dust and noise impacts associated with the transport of spoil on air and noise sensitive receivers in the Southern District could be minimised with the use of barges for transporting majority of surplus spoil.
Airborne train noise impacts on the noise sensitive uses within the project boundary would be minimal as the SIL alignment from South Horizons to Shan Wan Towers and from Nam Fung Portal to Admiralty would be in tunnel while from Aberdeen Channel Bridge to Ocean Park would be in viaduct with noise barriers/enclosures to ensure compliance with relevant noise criteria.
13.2.5.1 Construction Phase
Assessments have been based on the latest information obtained, with the implementation of the mitigation measures in form of quiet plant, movable noise barrier/ enclosure and fabric, the construction noise levels at most of the representative NSRs are predicted to comply with the noise standards stipulated in the EIAO-TM. Residual construction noise impacts are predicted at NSRs near Wong Chuk Hang Depot, Wong Chuk Hang Nullah, Entrance A of LET Station and South Horizons. The last resort, ITR, would be considered at the discretion of the Project Proponent, if required.
Residual ground-borne construction noise impacts are predicted at NSRs near Lei Tung Station with a duration of about three weeks to eight weeks.
13.2.5.2 Operation Phase
During the operation phase, the airborne and ground-borne noise impacts due to the operation of proposed SIL(E) through the tunnel and viaduct section have been predicted. The results indicated that there are noise exceedances of relevant noise criteria at NSRs. With the implementation of noise mitigation measures recommended in the form of noise barrier/ semi-enclosure for railway noise, specification of maximum sound power level of the fixed plant at stations, depot and ventilation shafts and buildings and resilient trackform for South Horizons Station, full compliance of Noise Control Ordinance and EIAO-TM criteria could be meet.
An Ecological Impact Assessment had been conducted for the proposed project. Ecological surveys were carried out between June 2008 to November 2009 which covered both the wet and dry season.
A total of 12 habitat types were identified within the Assessment Area, including woodland, degraded woodland, plantation, shrubland, marsh, stream, drainage channel, hillside grassland, agricultural land, wasteland, open field and developed area.
No adverse impacts on the Nam Fung Road Woodland SSSI and
Permanent loss of some area of woodland may be resulted for the construction of the railway facilities and buildings. Habitat compensation in full scale in terms of area will be provided to avoid potential residual ecological impact.
The construction of viaduct at WCH would cause an ecological impact to the ardeids foraging and roosting at WCH area through habitat loss and off-site disturbance during construction and operation phase. The potential impacts from loss of habitat would be mitigated by avoiding tree felling activities and site clearance at winter, when a large population of wintering egrets are present, and compensated by replanting of suitable tree species at adjacent area for provision of night roosting trees. The off-site disturbance to the night roosting ardeid would be mitigated by avoiding construction activities using PME near the ardeid night roost in the evening. With the full implementation of the suggested mitigation measures through avoidance, minimization and compensation, the potential impacts to the foraging and roosting ardeid would be brought to acceptable level, in considering that the impact would not bring a significant impact on the survival and reproductive success. The change of behaviour in response to the disturbance would not lead to a decline in population and thereby not considered as significant from a conservation perspective.
Five floral species of conservation interest were recorded within the Project Area: Gleditsia australis, Aquilaria sinensis, Lagerstroemia fordii, Pavetta hongkongensis and Houttuynia cordata. These plants should be considered for In-situ preservation as far as possible to avoid removal impacts.
As only small scaled and mitigated dredging works are involved in the construction of the railway bridge crossing the Aberdeen Channel, no significant adverse impact on marine ecology is anticipated. The marine piling and building of tipping hall for the Telegraph Bay Barging Point are also small in scale and thereby not expected to bring any significant impacts to marine ecology.
13.2.7.1 Construction Phase
The key issue in terms of water quality during the construction phase of the Project would be the potential for release of SS into the surrounding water from construction of pier/pier foundation of the railway bridge and potential for release of sediment-laden water from surface works areas, open cut excavation and tunnelling works.
Deterioration in water quality could be minimised to acceptable levels through implementing adequate mitigation measures such as control measures on sediment release, on site runoff and drainage from the works areas to minimise sediment spillage, construction runoff, and on-site treatment of tunnelling wastewater prior to discharge. Proper site management and good housekeeping practices would also be required to ensure that construction wastes and other construction-related materials would not enter the public drainage system and coastal waters. Sewage effluent arising from the construction workforce would also be handled through provision of portable toilets.
With the implementation of these recommended mitigation measures, no unacceptable impacts on water quality from the construction works for the Project are anticipated. Water quality monitoring during the course of marine construction works and site inspections during construction phase should be undertaken routinely to inspect the construction activities and works areas to ensure the recommended mitigation measures are properly implemented.
13.2.7.2 Operation Phase
Water quality impact from the railway bridge and viaduct
structures in Aberdeen Channel (Typhoon Shelter) (ATS) and Wong Chuk Hang
Nullah is not anticipated. The operational water quality impact for track
run-off and tunnel seepage would have no adverse water quality impact provided
that mitigation measures are incorporated in the design. Water quality impact from the fresh water
cooling system for the SIL(E) is not anticipated. Sewage and wastewater
arisings from the operation of the stations and depot would be treated so that
all treated effluent would meet the TM-DSS before discharge to the foul sewer
and would not cause adverse water quality impact.
13.2.8 Landscape and Visual Impact
13.2.8.1 Compatible with the Landscape Planning Framework
The proposed railway works encroach upon a number of zoning areas within seven Outline Zoning Plans which cover the proposed alignment. Areas zoned for Open Space, Government, Instruction and Community, Green Belt and Residential, Industrial etc. will be in conflict with the proposed works. However, for the large part the proposed works will be located along road corridors and the affected zoning areas will be restored to their original condition. Thus, the project will not lead to a permanent degradation of the landscape setting of an area following the full establishment of the recommended mitigation measures, and will not affect its viability in terms of being a landscape planning designation. The proposed scheme including the track alignment, the proposed above ground structures and associated developments largely fit within the planning and development control framework and will be integrated with the future outlook of this urban - rural landscape context.
13.2.8.2 Landscape Impact
With the implementation of responsive design of above ground structures in combination with the full establishment of tree planting within the affected amenity or sloping areas together with the preserved trees and restoration of the disturbed areas following the completion of the works, the potential impacts on the majority of the identified landscape resources would be negligible to slight.
The preliminary planting proposals for the proposed works
include some new trees utilising a combination of semi-mature, heavy standard,
standard and light standard sized stock within the general roadside planting
areas and semi-mature stock for feature trees at elevated level of proposed stations will mitigate for the potential
loss of existing trees on a 1:1 basis (new planting: trees recommended
for felling) in terms of the
overall number of trees affected.
Given that much of the proposed works will utilise tunnelling methods and that the proposed works areas will be restored following the completion of the works the identified LCAs will not for the most part be significantly impacted by the proposals. Impacts are likely to range from negligible to slight impact.
The landscape character of the Admiralty Commercial Landscape will be subject to relatively extensive construction phase works and their attendant disturbance to the setting and landscape amenity of these areas resulting in a moderate level of impact. However with the full implementation of the proposed mitigation measures these impacts will be alleviated to a slight adverse level of impact during the operational phase of the project.
The proposed innovative and responsive design of the viaduct structures and their associated noise attenuation measures, their proposed alignment and horizontal form; and the introduction of extensive tree and shrub planting together with the preserved trees will serve to mitigate much of the potential adverse impacts. It is likely that with the full establishment of the proposed mitigation measures and the growth to maturity of the proposed tree and shrub planting the proposed scheme will form a relatively small component within the future landscape context.
13.2.8.3 Visual Impact
As has been described above the majority of the works areas disturbed by the proposed works will be restored to their original condition following the completion of the construction phase of the project. These restoration measures in combination with the implementation of new amenity areas upon sectional completion of station and railway alignment will do much to mitigate potential impacts. However the key mitigation measure for the components of the proposed scheme has been the adoption of innovative and responsive designs for the proposed engineering structures including for instance the viaduct section, its associated noise barriers and enclosure and the above ground structures associated with the tunnel sections of the proposed alignment. As such the level of visual intrusion arising from the introduction of these structures further mitigated by the proposed tree and shrub planting will therefore be alleviated to an extent.
The majority of the works areas will be restored to its original condition following the completion of the construction works and these proposals will be combined with new amenity areas implemented following the sectional completion of the station and above ground structures, and the railway alignment. Roadside tree and shrub planting will be introduced, where space allows, and the responsive design of built structures will be adopted. Through the implementation of the proposed mitigation strategies the visual intrusion of the above ground structures such as the station entrances, vent shafts, viaduct sections, bridge, tunnel portal and plant buildings will be significantly reduced.
In accordance with
Annex 10 of the EIAO-TM, the landscape and visual impacts of the proposed works
would be ‘acceptable with mitigation measures’ that is to say ‘there would be some adverse effects,
but these can be eliminated, reduced or offset to a large extent by specific
measures’.
A QRA has been carried out to assess the hazard to life issues arising from the storage and transport of explosives during construction of the SIL(E) Project.
The assessment results show that the societal risk lies within the ALARP region when compared to the criteria stipulated in Annex 4 of the EIAO-TM. The criterion of the EIAO-TM for Individual Risk is met. An ALARP assessment has been carried out by identifying all practicable mitigation measures and assessing the cost effectiveness of each measure in terms of the risk reduction achieved and the cost of implementing the measures.
The location of all relevant Potentially Hazardous Installations (PHIs) have been reviewed with regard to the SIL(E) alignment, explosives magazine and other works areas for both the construction phase and the operation phase of the project. The only PHI that requires assessment under the conditions of the EIA Brief is the Shell’s LPG Transit Depot/Bulk Domestic Supply at Lee Nam Road (the LPG Depot), since part of the work sites and plant buildings as well as the South Horizons Station will be located on the verge of its 500 m Consultation Zone (CZ). The assessment results show that the increased societal risk arising from the incremental population during construction and operational phases of the SIL(E) project lies within the acceptable region when compared to the criteria stipulated in Annex 4 of the EIAO-TM. The criterion of the EIAO-TM for Individual Risk is met.
13.2.10 Waste Management Implication
13.2.10.1 Construction Phase
Waste types generated by the construction activities are likely to include marine sediment, C&D material (from tunnelling works, earth works for the depot and underground stations construction), general refuse from the workforce, and chemical waste from the maintenance of construction plant and equipment.
A review of the sediment quality data from the marine site investigation indicated that the marine sediments to be dredged/excavated for installation of the pier/pier structure in Aberdeen Channel were classified as Category H, Type 2 - Confined Marine Disposal. The volume requiring marine disposal was estimated by the preliminary design consultant to be less than 100m3. With the implementation of the recommended mitigation measures and management procedures in accordance with the requirements of ETWB TCW No. 34/2002, no adverse impact was predicted.
Provided that these wastes are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts is not expected during construction phase.
13.2.10.2 Operation Phase
Waste types generated by the operation activities are likely to include general refuse from the workforce, and industrial and chemical waste from the maintenance activities. Provided that these wastes are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts is not expected during operation phase.
13.2.11.1 Construction Phase
The land contamination assessment has been carried out which included a review of historical/current land uses, desktop review and site inspection. Other relevant information was also collected from related Government Departments during the assessment exercise.
All results have indicated insignificant contaminated land issue at ADM, WCH and LET sites. For OCP site, no similar issue was identified as land remediation had been carried out in the area south of OCP station (the former HKSM area) during another EIA study. For the area north of OCP station, i.e. the existing CBD, there was no evidence to show any sign of past activities that would potentially contributed to significant land contamination. As a result of the existence of a vehicle washing machine, a prudent approach in further site investigation was adopted and soil sampling strategy was proposed.
For the SOH site, it was where the former HEC Power Station and Shell Oil Depot located before South Horizons. Land contamination could be an issue due to the operation of the power plant as well as oil depot. Despite the aforesaid, it was believed the whole ground condition could have had seriously disturbed during the construction of South Horizons. As such, less intensive site investigation strategy was proposed.
SI was conducted in December 2008, June and July 2009 for the SOH and OCP stations where soil samples from five sampling locations were taken for laboratory analysis. Subsequent results have indicated the “Chemicals of Concern” (COC) of all locations at both SOH and OCP stations were well below their respective RBRGs “Industrial” criteria. Details of sampling and testing results are contained in the Contamination Assessment Report (CAR) in Appendix 9.2.
In view of the desktop review results and the Site Investigation Results the significance of contamination to be low in the stations footprints as well as the concerned areas to the north and south OCP station. Bulk excavation of soil for land remediation is therefore not expected at this stage.
13.2.11.2 Operation Phase
During the operation phase, it is expected that defined procedures in handling chemicals for the operation of a depot and railway station will be implemented as part of the MTRCL’s policy. As such, no land contamination implication is anticipated.
During construction, it is anticipated that the construction activities should be controlled in accordance with appropriate mitigation measures stipulated under the Air Pollution Control (Construction Dust) Regulations. With the proper implementation of dust suppression measures, adverse dust impacts would not be anticipated.
13.2.13 Cultural Heritage Impact
With the implementation of the recommended mitigation measures, the SIL(E) would have no adverse impacts on the cultural heritage resources in the study area during both construction and operation phases.