13. conclusion

13.1 This EIA Report has provided an assessment of the potential environmental impacts associated with the construction and operation of the WIL Project, based on the preliminary engineering design information available at this stage.

13.2 The assessment has been conducted, in accordance with the EIA Study Brief (No. ESB–130/2005) under the EIAO for the Project, covering the following environmental issues:

n Airborne noise impact

n Ground-borne noise impact

n Landscape and Visual Impacts

n Cultural Heritage Impact

n Waste Management Implications

n Land Contamination

n Water Quality Impact

n Air Quality Impact (Construction Stage)

n Hazard to Life

13.3 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 WIL Project, to ensure compliance with environmental legislation and standards during both the construction and operation phases. The Implementation Schedules listing the recommended mitigation measures are presented in Section 14.

13.4 Overall, the EIA study for the WIL 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. Table 13.1 summarises 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. Environmental monitoring and audit requirements have been recommended, where necessary, to check on project compliance of environmental legislation and standards.

Table 13.1 Summary of Key Environmental Outcomes / Benefits

Area/Issue	Environmental Outcomes / Benefits and Mitigation Measures
The Project	The Project comprises the following elements: · Approximately 3km of underground railway from Sheung Wan via Sai Ying Pun and University of Hong Kong to Kennedy Town · An overrun tunnel extending from KET Station to the Ex-police Quarters site. · Three stations: Kennedy Town Station (KET Station); University Station (UNI Station); and Sai Ying Pun Station (SYP Station) · Ventilation shafts, cooling towers and chillers for stations and railway tunnel. 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 Victoria Road, comprising several underground rock caverns connected with a tunnel. The excavated materials arising from the WIL construction would reach ground level via two main construction shafts located at the Kennedy Praya site and the King George V Memorial Park site. The materials will be disposed of via barging points at the Kennedy Town Incinerator and Abattoir site (KET Abattoir site) and the Western District Public Cargo Working Area (Western PCWA) sites respectively.
Environmental Benefits of the Project	The use of electrically powered trains which are emission free would enable WIL to become not only an efficient but environmentally friendly mass carrier. The WIL sited within intensive developments and employment centres would help encourage the usage of railways and thereby reduce reliance on road-based transport. The capacity of the existing heavily-loaded road networks could be freed up, which would help to improve the current traffic congestion problems at the Western District. This would also help to reduce vehicular noise, air emissions and improve overall environmental quality.
Environmentally Friendly Design Recommended to Avoid Environmental Problems	Design measures have been taken to preserve the tree walls in the Kennedy Town Playground and along Forbes Street. This has been achieved by placing the cut and cover box containing the station as far to the east as topography permits and adopting a radical internal station design to minimize the station length. All Declared Monuments and graded historical buildings within the Project boundary have been identified in the early stage of the preliminary design. The Project has been designed to avoid causing direct physical impacts on these heritage resources. The entire WIL alignment will be constructed underground. Airborne train noise impacts and the need for erecting noise barriers and enclosures could be avoided. 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 site formation for the Summit off site by sea, so as to avoid/reduce impacts arising from land based transport. An enclosed conveyor belt system is proposed for conveying the excavated material from the construction shaft down to the barging point at the Western PCWA. This would reduce impacts to the environment due to haulage.
Population and Environmentally Sensitive Areas Protected	With the adoption of environmentally design mentioned above, major environmentally sensitive receivers protected would include tree walls in the Kennedy Town Playground and along Forbes Street, Declared Monuments and graded historical buildings within the Project boundary. Potential construction dust and noise impacts associated with the transport of spoil on air and noise sensitive receivers in the Western District could be minimised with the use of barges for transporting majority of surplus spoil. There would not be any airborne train noise impacts on the noise sensitive uses within in the Project boundary as the entire WIL alignment would be in tunnel.
Airborne Noise	Unmitigated cumulative construction noise levels due to the proposed works for the construction of WIL were predicted. The assessment results indicated that the proposed works of the Project would result in noise exceedance (up to 22dB(A)) of the EIAO-TM construction noise criteria for non-restricted hours. In view of this, mitigation measures including good site practices, quieter plant, silencer, movable noise barrier, temporary noise barrier, noise enclosure, noise insulating fabric, “Noise Control Curtain”, noise insulating cover, acoustic enclosure and decking over the excavation area/lift shaft were recommended to reduce the noise levels. After mitigation, noise levels at most of the NSRs are predicted to comply with the EIAO-TM daytime construction noise criterion. However, some NSRs including KET 3-5, KET7, KET9, UNI1, UNI10-12, SYP1-5, SYP 7-13, SYP16 and GT5-6 located in close proximity to the works areas would still be exposed to noise levels exceeding the EIAO-TM noise criteria for a short period of time. The ITR has been considered for the affected NSRs. With reference to the criteria developed in the East Rail Extension Hung Hom to Tsim Sha Tsui EIA Final Report (ERE-EIA), the criteria would be dependent on the severity of the residual noise impact and duration of noise exceedance after implementing all practical direct mitigation measures. NSRs which were considered to be eligible for ITR provision were identified. During operation phase, predicted noise levels at all NSRs arising from the fixed plant of the Project would comply with the EIAO-TM criteria providing fixed plant is designed to comply with NCO. In this case, no adverse fixed plant noise impacts would be expected.
Groundborne Noise	During construction phase, the drill and blast alternative is not considered with respect to noise annoyance, as the duration of blasting is very short and infrequent. No assessment has been carried out regarding noise annoyance impacts within any of the identified sensitive receivers. Moreover, the TBM construction method is viable for tunnel formation along the WIL, with possible operational prohibition during night time hours near SHW and UNI stations. Ground-borne train noise has been predicted at representative sensitive receivers. Results indicated that vibration mitigating trackform would be required at some sections of the WIL alignment as shown in Figures 4.6-4.8 in order to provide sufficient attenuation to meet the stipulated criteria, and there would not be any adverse residual impacts.
Landscape and Visual	Potential landscape and visual impacts during construction and operation of WIL would be partly reduced after applying mitigation measures such as tree protection particularly for the Forbes Street and KGV Memorial Park tree walls, responsive design of above ground structures such as vent shafts and chillers, and sympathetic slope works design. The permanent loss of children play facilities and landscape sitting out area for local residents and neighbourhood nearby cannot be mitigated, even though the LCSD playground will be compensated at the existing Kennedy Town Swimming Pool site. Besides, the tree pruning works will deform and scar several nice specimens during the transplanting process. The overall landscape and visual quality would be further enhanced by applying attractive streetscape design with provision of tree planting. With implementation of mitigation measures, residual impacts of the WIL are considered to be acceptable, with reference to the criteria defined in Annex 10 of the EIAO TM.
Cultural Heritage	The WIL project would have no adverse impacts on the cultural heritage resources in the study area, during both construction and operation phases, with the implementation of the archaeological watching brief, recommended vibration and landscape/visual mitigation measures.
Waste management implications	Construction waste arisings have been identified based on the proposed construction activities and would comprise C&D material, general refuse and chemical waste. Provided that the identified waste arisings are to be handled, transported and disposed of using approved methods and the recommended good site practices are to be followed, adverse environmental impacts would not be expected during the construction phase. The waste management practices of waste arisings generated during the operational phase of the WIL would be similar to arrangements currently in operation on the existing Island Line and would pose no impact.
Land Contamination	Based on a review of historical/current land uses in respect of land contamination, including a desk-top review and site inspection, around the proposed WIL alignment and Works Areas, no land contamination issues in relation to the WIL construction was envisaged.
Water quality	Water quality impacts from construction activities would be controlled by implementing the recommended mitigation measures, such as control measures on site runoff and drainage from the works areas to minimise construction runoff, and particularly on-site treatment of tunnelling wastewater prior to discharge. The operational water quality for track run-off and tunnel seepage would have no adverse water quality impact provided that mitigation measures are incorporated in the design. The fresh water cooling system for the WIL would not be expected to result in unacceptable impacts on water quality. Sewage and wastewater effluents arisings from the operation of the stations would be discharged to the foul sewer and would not cause adverse water quality impact.
Hazard to Life	A QRA has been carried out to assess the hazard to life issues arising from the storage, use and transport of explosives in the proposed underground magazine and the construction sites of the Project. Assessment results indicated that the individual and societal risk is within the acceptable limit of the risk guidelines in the Annex 4 of EIAO-TM.
Air quality (Construction Stage)	Potential dust impacts would be generated from demolishment of some existing structures, excavation activities, material handlings, wind erosion, temporary stockpiles, spoil removal, material delivery, operation of temporary magazine site, barging points and rock crushing plants during the construction phase. Fugitive dust impacts would be controlled by implementation of dust suppression measures stipulated in Air Pollution Control (Construction Dust) Regulation, good site practices and proposed mitigation measures. The predicted TSP levels at the representative ASRs would comply with the statutory requirement.