TABLE OF CONTENTS
The existing Mass Transit Railway (MTR) Island Line (ISL)
provides mass transit railway services to major population and employment
centres along the north
The extension of the ISL to Western District is known as the
West Island Line (WIL) (hereafter referred to as “the Project”). The route length of the fully
underground WIL is approximately
1.3 This Executive Summary provides the key findings of the EIA Report, including an assessment of potential environmental impacts from the construction and operation phases of the Project, and recommendations for control measures to comply with environmental legislation and standards.
2.1 The Project comprises the following elements:
· 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 magazine is proposed at an
abandoned site at
The excavated materials arising from the WIL construction
would reach ground level via four main construction shafts respectively located
at the ex-Police Quarter at Kennedy Town, Kennedy Praya site, Hill Road Rest
Garden and Sai Woo Lane in SYP.
They 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 (
2.4 Based on the preliminary design information, the Project is scheduled to commence in early 2009 for completion in late 2013 / early 2014.
2.5 The WIL, as an extension of the MTR Island Line, is a designated project under the EIA Ordinance (EIAO) falling into the following categories:
· A railway and its associated stations (Item A.2 of Part I of Schedule 2 of the EIAO)
A railway tunnel more than
2.6 The temporary magazine consisting of underground rock caverns is considered a designated project under Item Q.2, Part 1 of Schedule 2 of the EIAO.
2.7 MTRC considers that the views and support of the community are important in the planning and design of the WIL. Extensive public consultation has been conducted during the preliminary design of the Project. The public generally welcomes and looks forward to the implementation of WIL as early as possible.
2.8 A key public concern was related to the need to preserve the tree walls along Forbes Street Playground. In response to this, the cut and cover KET Station has been located as far away from the tree walls as possible, with a radical internal station design to minimize the station length, avoiding and minimizing the disturbance to the tree walls.
3.1 The EIA Study was conducted in accordance with EIAO Study Brief No. ESB-130/2005, following the guidelines on assessment methodologies in the Technical Memorandum on Environmental Impact Assessment (EIAO-TM). A conservative approach was adopted in the assessment based on worst case assumptions.
3.2 The EIA study process was initiated at an early stage of the planning and design of the Project. This has allowed incorporation of environmental considerations into the development of the scheme design, particularly important given the substantial site constrains and dense population of the Western district.
3.3 The main findings of the EIA study are summarized below.
3.4 The potential source of noise impact during the construction phase of the Project would mainly be the use of powered mechanical equipment (PME) for various construction activities, including site possession, building demolition, excavation, station construction, tunnel construction, backfilling and reinstatement works. As the area is densely populated, in the absence of any control measures, construction noise levels exceeding the EIAO-TM noise assessment criteria would be expected at a number of noise sensitive receivers (NSRs) in the vicinity of the works areas.
3.5 Construction noise control measures have been incorporated into the construction method design, such as use of quieter construction methods and equipment, movable and temporary noise barriers, full enclosure, noise insulating fabric, acoustic enclosure, noise insulating cover and decking over excavation areas. With these measures in place, there would be compliance with the noise criteria at most NSRs.
3.6 There would nevertheless be some exceedance of the noise criteria at some NSRs in close proximity to the works areas for KET Station, vent shaft for the overrun tunnel, Entrances B1, B2 and C1 and Hill Road vent shaft of UNI Station, Entrances A1 and A2, B1 and B2, B3 and C of SYP Station, as well as the ground treatment works at New Market Street. Direct on-site noise control measures are considered as far as practicable, given site constraints and safety factors. Indirect technical remedies (ITR) in the form of window insulation are recommended as a last resort for mitigating the residual construction noise impacts. ITR would generally require the provision of upgraded window glazing for the noise sensitive facades exposed to excessive residual impacts, and provision of air-conditioning. The estimated number of NSRs considered to be eligible for ITR provision would be approximately 109.
3.7 During the operational phase, the main source of airborne noise impact would be the fixed plant used for tunnel ventilation and cooling systems for stations and adits. The maximum allowable Sound Power Levels (SWL) has been incorporated into the fixed plant design to comply with the SWL criteria. No adverse operational noise impact at NSRs would therefore be envisaged.
3.8 Potential ground-borne construction noise impacts would arise mainly from rock breaking activities and tunnel boring. The noise impacts on neighbouring sensitive receivers are predicted to meet the statutory requirements. Therefore no adverse ground-borne construction noise impact was expected and no mitigation measures would be required.
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 near
Potential landscape and visual impacts have been considered
during the development of the project design to avoid direct impacts on
important landscape resources, including the tree walls at
3.11 With the implementation of mitigation measures such as tree protection measures, good site practices and aesthetic hoardings during the construction phase, and architectural and soft landscape treatment for the operation phase, landscape and visual impacts pertinent to the Project would be considered acceptable.
3.12 The key cultural resources identified within the Study Area included five Declared Monuments, seventeen graded historical buildings, as well as buildings and structures that are not yet graded but of high architectural and historical significance. The scheme design of the WIL has avoided direct impact on these resources.
3.13 There may be potential landscape and visual impacts. With the implementation of recommended mitigation measures, no adverse landscape and visual impacts to the identified built heritage are expected.
3.14 There may be potential vibration impacts resulted from tunnel boring or blasting. By controlling the vibration levels from the proposed construction works, no adverse vibration impacts would be expected. No adverse vibration impacts due to operational trains would be expected as there would be sufficient separation distance maintained between the rail tracks and heritage sites.
3.15 According to records of Antiquities and Monuments Office, no known sites of archaeological potential were identified within the WIL Project boundary. As a precautionary measure, a watching brief by a qualified archaeologist is recommended for the identification of any historical finds in several works areas which might have a potential for finds and remains of archaeological interest to be found, considering geology, topography and landuse.
3.16 Waste types generated by the construction activities are likely to include construction and demolition materials (e.g. from site clearance, excavation and tunnelling works), general refuse, and chemical waste from the maintenance of construction plant and equipment. These wastes will be handled, transported and disposed of following Government guidelines and good site practices.
3.17 The main waste types in the operation phase would be general refuse from the public, staff and commercial operators at the stations, and chemical wastes from operational activities at the stations. The handling, collection, transportation and disposal practices of the identified waste would follow the existing arrangements currently in operation at the stations on the existing Island Line.
3.18 A review of historical and current landuse of the Project area identified no sites with significant land contamination implications.
3.19 Potential impact to water quality during the construction phase would be avoided through implementing control measures on site runoff and drainage from the works areas, such as minimizing construction runoff, and on-site treatment of tunnelling wastewater prior to discharge. Good site management and housekeeping practices would also be in place to prevent any construction wastes and other construction-related materials from entering the public drainage system and coastal waters. Sewage effluent arising from the construction workforce would be managed through provision of portable toilets.
3.20 During operation, railway track run-off and tunnel seepage would have no water quality impact. The fresh water cooling system for the WIL is not expected to result in any adverse impacts on water quality. Sewage and wastewater arisings from the operation of the stations would be discharged to foul sewers.
3.21 The storage, transport and use of explosives for the WIL construction have been assessed in a Quantitative Risk Assessment (QRA). The results show that societal risk and individual risk are within the acceptable limit of the risk guidelines in the Annex 4 of EIAO-TM.
3.22 Construction dust from demolition, excavation, materials handling, spoil removal and wind erosion, as well as operation of rock crushing plants and barging facilities, would be the main source of air quality impacts. With the implementation of mitigation measures specified in the Air Pollution Control (Construction Dust) Regulation, as well as dust control measures for rock crushing plants, barging facilities and stockpiles, potential dust impacts at adjacent air sensitive receivers would comply with the established limit.
4.1 An environmental monitoring and audit (EM&A) programme will be implemented for the Project, to check effectiveness of the recommended mitigation measures and compliance with relevant statutory criteria.
5.1 This EIA study has identified and assessed potential environmental impacts of the Project, in accordance with the EIA study brief and EIAO-TM guidelines. Overall, the study predicts that with the implementation of the recommended environmental control measures during the construction and operational phases, the Project would comply with Government environmental criteria and legislation. This EIA has also demonstrated the acceptability of residual impacts from the Project and the protection of the population and environmentally sensitive resources. An EM&A mechanism has been recommended for implementation to check environmental compliance.