1.1
The existing Island Line (ISL) provides mass transit railway
services to major population and employment centres along the north
1.2
The extension of the ISL to Western District is known as the
West Island Line (WIL) (hereinafter referred to as “the Project”). The route length of the fully underground WIL is approximately
1.3
In October 2005, ENSR Asia (HK) Ltd. was commissioned by MTRC to undertake the Environmental Impact Assessment (EIA) Study
of the Project.
1.4
The WIL as an extension of the MTR Island Line is a Designated Project (DP) under the EIA Ordinance 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 800m in length between portals (Item A.7 of Part I of Schedule 2 of the EIAO)
1.5
An application for an EIA Study Brief was made to the
Environmental Protection Department (EPD) and the EIA Study Brief No. ESB–130/2005 for the WIL has been issued
under the EIAO.
1.6
A temporary project specific magazine will be built for overnight
storage of explosives that will be used for construction of underground railway
facilities. The magazine will consist of
a few underground rock caverns connected with a tunnel. The underground magazine itself is considered
as a DP under Item Q.2, Part 1 of Schedule 2 of the EIAO.
1.7
The future decommissioning of the underground explosives
magazine is a Designated Project under
Item 11 in the EIAO Schedule 2 Part II and an Environmental Permit will be required prior to start of
decommissioning work.
1.8
The purpose of the EIA Study is to provide information on the
nature and extent of environmental impacts arising from the construction and
operation of the Project and associated mitigation, and
related activities that
take place concurrently. This information will contribute to decisions on:
§ the overall acceptability of any adverse environmental consequences as a result of the Project and the associated activities of the Project
§
the conditions and requirements
for the detailed design, construction and operation of the Project to mitigate
against adverse environmental consequences
§
the acceptability of residual
impacts after the proposed mitigation measures are implemented
§
1.9
Specific objectives of the EIA study are as follows:
§ to describe the Project, associated works, and any phasing of development together with the requirements and environmental benefits for carrying out the Project
§ to identify and describe the elements of the community and environment likely to be affected by the Project and/or likely to cause adverse impacts to the Project, including both the natural and man made environment and the associated environmental constraints
§ to describe the constraints leading to and considerations given in selecting the proposed alignment, station locations, locations and size of work areas, underground work construction methods including considerations of the comparative benefit(s) and dis-benefit(s) of alternative alignments, station locations, works sites and underground / tunnelling construction methods; to provide reasons for selecting the preferred option(s) for the above; and to describe the part environmental factors played in the whole selection process to include environmental benefit(s) and dis-benefit(s)
§ to identify and quantify emission sources and determine the significance of impacts on sensitive receivers and potential affected uses
§ to identify and quantify waste management requirements and land contamination prevention requirements, and to propose measures to avoid in the first instance or mitigate these impacts
§ to identify any negative impacts on sites of cultural heritage and to propose measures to avoid in the first instance or mitigate these impacts
§ to identify and quantify any potential landscape and visual impacts and to propose measures to avoid in the first instance or mitigate these impacts
§ to propose the provision of mitigation measures so as to minimize pollution, environmental disturbance and nuisance during construction and operation of the Project
§ to investigate the feasibility, practicability, effectiveness and implications of the proposed mitigation measures
§ to identify, predict and evaluate the residual environmental impacts (i.e. after practicable mitigation) and the cumulative effects expected to arise during the construction and operation phases of the Project in relation to the sensitive receivers and potential affected uses
§ to identify, assess and specify methods, measures and standards, to be included in the detailed design, construction and operation of the Project which are necessary to mitigate these environmental impacts and cumulative effects and reduce them to acceptable levels
§ to investigate the extent of the secondary environmental impacts that may arise from the proposed mitigation measures and to identify constraints associated with the mitigation measures recommended in the EIA study, as well as the provision of any necessary modification
§ to design and specify the environmental monitoring and audit requirements to ensure the effective implementation of the recommended environmental protection and pollution control measures.
1.1
The present study has been conducted in accordance with the
requirements of the EIA Study Brief issued by EPD (ESB-130/2005) and the guidelines on assessment methodologies
provided in Annexes 12 to 19 of the Technical Memorandum on Environmental
Impact Assessment Process (hereinafter referred to as the EIAO-TM). A general description of the approaches and
methodologies adopted for the assessment are described below, and detailed
descriptions are to be found in the relevant technical sections to follow.
Description of the Environment
1.2
The relevant characteristics of the existing environment
have been identified and described, so as to form a baseline for the
identification and prediction of environmental impacts likely to arise from
implementation of the project. Baseline
environmental surveys were carried out to determine the existing environmental
conditions on the site and in all environs likely to be affected by the
proposed Project. The baseline
conditions including the existing noise environment, air quality, water
quality, cultural heritage and the landscape and visual quality have been
described in the report.
1.3
Relevant reports and drawings have been reviewed and
relevant findings from past studies were incorporated where appropriate in this
EIA Report.
Impact Prediction
1.4
This Study has been undertaken following the guidelines on
assessment methodologies given in Annexes 12 to 19 of the EIAO-TM. Quantitative predictive tools have been used
for the prediction of environmental impacts associated with airborne construction and fixed
plant noise, ground-borne construction and
train noise and air quality. The predictions were based on internationally
recognised methods. For instance, the
methodologies described in the Technical Memorandum on Noise from
Construction Work other than Percussive Piling (GW-TM) under the Noise
Control Ordinance (NCO) were adopted to predict the construction noise
impact. Fixed noise source impacts were
predicted by standard acoustic principles. Besides, the United
States Environmental Protection Agency (USEPA) approved air dispersion model, namely Fugitive Dust Model (FDM) (1993 version), was used to predict the construction dust impact.
1.5
These methodologies have previously been applied in similar
situations in other EIA studies (e.g. EIA Report for the Kowloon
Southern Link Project). They have generally been accepted for use in
assessing environmental impacts and for the comparison of prediction results
with EIAO-TM standards. There remain
some limitations of the methodologies such as the accuracy of the predictive
base data for future conditions, e.g. weather conditions. Uncertainties in the assessment of impacts have been
considered when drawing conclusions from the assessment. For instance, realistic worst-case
assumptions have been used in the assessment in order to provide a conservative
assessment of environmental impacts. As
an example, total suspended
particulates levels at representative air sensitive receivers were predicted
based on the worst case meteorological condition. Ground-borne train noise impacts were predicted using the peak train
frequency.
Impact Evaluation
1.6
The anticipated changes and effects as a result of the
proposed Project were evaluated with respect to the criteria described in
Annexes 4 to 10 of the EIAO-TM. As far
as possible and as appropriate to the needs of the assessment, the evaluations
have been presented quantitatively.
Impact Mitigation
1.7
Mitigation measures have been identified and evaluated with
the aim to avoid, reduce or minimise/ remedy the impacts. The priority in selecting mitigation measures
is the avoidance of impacts. The
effectiveness of the proposed mitigation measures has been assessed and any
residual environmental impacts have been clearly defined. The various mitigation measures have been set
out in an implementation schedule that clearly identifies each measure, when
and where it needs to be applied, and the parties responsible for both
implementation and, where required, maintenance of the mitigation measure.
1.8
The environmental issues covered
in the EIA study and their assessment areas, as specified in the EIA Study
Brief (No. ESB-130/2005), is presented below:
§
Airborne and ground-borne noise
impact – assessment area would be within
§
Landscape and visual impact -
landscape impact assessment areas would be
§
Cultural heritage impact - area
within
§
Water quality impact - the
§ Waste management implication and land contamination assessment.
§ Hazard to life issues associated with the transport, storage and use of explosives.
§
Construction stage air quality
impact – areas within
1.9
This EIA Report presents the
environmental assessment findings based upon the available design information
for WIL at the time of preparing the report.
This report provides information on key environmental issues and
evaluates the environmental impacts associated with the construction and
operation of WIL. Mitigation measures
would also be proposed where necessary to mitigate the adverse impacts to
acceptable levels.
1.10
The proposed WIL scheme is illustrated in Figure 1.1. Details of the proposed scheme are presented
in Section 2.
1.11
This EIA Report comprises fourteen sections, as outlined below:
§ Section 1 presents the introduction of this EIA Study.
§ Section 2 presents a description of the Project, including the project background and construction activities.
§ Section 3 identifies and assesses potential airborne noise impacts arising from the construction and operation of the Project.
§ Section 4 identifies and assesses potential ground-borne noise impact arising from the construction and operation of the Project.
§
Section 5 identifies and
assesses potential temporary and permanent landscape and visual impacts arising
from the Project.
§
Section 6 identifies and
assesses potential impacts on cultural heritage arising from the Project.
§
Section 7 identifies and
assesses potential impacts associated with waste generation during construction
and operation of the project and describes measures for storage and handling of
waste material.
§ Section 8 identifies and assesses issues arising from areas of potential land contamination.
§ Section 9 identifies and assesses potential water quality impacts associated with the construction and operation of the Project.
§ Section 10 identifies and assesses potential hazards associated with transport, use and overnight on site storage of explosives for the construction of the Project.
§ Section 11 identifies and assesses potential air quality impacts arising from the construction stage of the Project.
§ Section 12 highlights the Environmental Monitoring and Audit (EM&A) requirements.
§
Section 13 presents the overall
conclusion and summary of environmental outcomes
§ Section 14 presents the Implementation Schedules of recommended mitigation measures for various environmental issues.