1.1
The Shatin to Central Link (SCL) is one of the
priority railways recommended for implementation in the Railway Development
Strategy 2000. It is also one of the ten large-scale infrastructure projects
announced by the Chief Executive in his 2007-2008 Policy Address. MTR
Corporation Limited (MTR) has been entrusted to plan and design for this
project.
1.2
The SCL is strategically important for connecting the existing railway
lines into an integrated rail network. The east-west connection will allow the
setup of a 57km east-west corridor across the city connecting Wu Kai Sha with Tuen Mun
via Kowloon;
whilst the north-south connection will operate over a 41km north-south corridor
with services originating in Lok Ma Chau or Lo Wu
travelling via the existing East Rail Line (EAL) to Admiralty Station (ADM).
This will enable a direct transportation linkage between Mainland China and Hong Kong Island.
1.3
The Legislative Council Brief on the SCL submitted by the Transport and
Housing Bureau (THB) in March 2008 indicated that the SCL would be implemented
in two phases. The first phase would include the realignment work for the
existing EAL tracks from Mong Kok
East Station (MKK) to the new platforms at Hung Hom
Station (HUH) and the extension of the Ma On Shan Line
(MOL) from Tai Wai Station to HUH. The second phase
would cover the section from HUH across the harbour to the Causeway Bay Typhoon
Shelter (CBTS), Exhibition Station (EXH) and then to ADM.
1.4
For the second phase, a key aspect of constructing the SCL inside the
CBTS will be the coordination of interfaces with the Central-Wan Chai Bypass and Island Eastern Corridor Link (CWB) project
of the Highways Department, which involves the construction of cut-and-cover
tunnel from temporary reclamation in the CBTS. Since this will overlap with the
target construction period of SCL, there is a need to address how the SCL can
be integrated with the CWB tunnel works to minimize the extent and duration of
temporary reclamation for both projects in the CBTS in view of the feedback from
consultation with stakeholders and users of the CBTS. Eventually, tunnel protection works for the SCL at the CBTS is
proposed to be undertaken by Highways Department together with the main CWB
works.
1.5
The SCL Protection Works and associated works at CBTS (hereinafter known
as “the Project”) involve the construction of a 160m tunnel box by
cut-and-cover method at the crossing above the CWB tunnels. Temporary
reclamation is required and will be authorized under the Foreshore and Sea-bed
(reclamations) Ordinance.
1.6
The Project is a Designated Project (DP) under Item C.12 (b), Part I of
Schedule 2 of the Environmental Impact Assessment Ordinance (EIAO) (Cap. 499) –
“A dredging operation which is less than 100m from a seawater intake point”.
The Project will be undertaken together by the CWB contractor. The temporary reclamation in the Project
together with that in the CWB project will be another designated project under
Item C.1, Part 1, Schedule 2 of the EIAO. The implementation of the Project therefore
requires an Environmental Permit (EP) under the EIAO.
1.7
An application for an Environmental Impact Assessment (EIA) Study Brief
was made to the Environmental Protection Department (EPD) and the EIA Study
Brief No. ESB–213/2010 for the Protection Works has been issued under the
EIAO. AECOM Asia (HK) Company Limited
(AECOM) was commissioned by the MTR as the Consultant to conduct this EIA study
for the Protection Works.
1.8
This Executive Summary highlights the key findings of the EIA study for
the Project to comply with the EIAO.
Purpose and Scope of the
Project
2.1
A key aspect of the construction of Shatin to Central Link - Hung Hom to Admiralty
Section (hereafter known as SCL (HUH-ADM)) inside the CBTS will be coordination of the interfaces with the CWB
project. The CWB will be constructed in
cut-and-cover tunnel from temporary reclamation in the CBTS. Construction of the CWB will tentatively
start in the third quarter of 2010 and will overlap with the target
construction period of the SCL. There is
a need to address how the SCL can be integrated with the proposed CWB project
to minimize the extent and duration of reclamation for both projects in the
CBTS.
2.2
The purpose of the Project is to temporarily reclaim land for
construction of a section of tunnel box for SCL by cut-and-cover method at the
crossing above the CWB tunnels within the CBTS. The
Protection Works is limited to civil and structural elements and cannot serve
to function for any railway service or operation. The prime objectives
of the Project are:
·
To avoid repeated
temporary reclamation and minimize the extent and duration of reclamation in
the CBTS by constructing the SCL Protection Works together with the main CWB
works that is undertaken by Highway Department.
·
To ensure future
construction of the SCL on both sides of the CWB tunnels is protected and
ensure its feasibility without damaging or unduly affecting the CWB tunnels
which could be operational by then.
2.3
The Project comprises
the following key elements:
·
Temporary
reclamation, which occupies about 0.7ha of Government foreshore and sea-bed (of
which 0.3ha is already authorized under CWB project, i.e. additional
reclamation of 0.4ha is required).
·
Dredging works at
the southeast corner of the CBTS to provide space for temporary relocation of
anchorage area due to the additional temporary reclamation for the Project.
·
Construction of a
section of the twin track railway tunnel structure (approximately 160m long)
above the proposed CWB located entirely offshore within the CBTS.
·
Relocation of the temporary
Royal Hong Kong Yacht Club (RHKYC) jetty within the CWB temporary reclamation
to a new location.
·
Removal of the
temporary reclamation, except the small area at the southwest corner of the
reclamation (which will be removed by the SCL (HUH-ADM) upon completion of the future SCL tunnels
connecting to the proposed South Ventilation Building (SOV)).
2.4
Location, boundary
and general layout of the Project are illustrated in Figure Nos. NEX2213/C/331/ENS/M50/501 to NEX2213/C/331/ENS/M50/503.
Benefits of
the Project
2.5
Since the Project
will interface with CWB project at the CBTS, there is a need to address how the
two projects can be integrated, not only to optimize the use of temporary
reclamation provided by CWB but also to minimize the impacts on the users of
the CBTS. Based on feedback from consultation with stakeholders and users of the CBTS, they opined that there should be a better
coordination with the CWB project to minimize disturbance to the moorings and
operations of the typhoon shelter and expedite the works to avoid prolongation
of the impacts.
2.6
The Project is a
win-win option to both SCL and CWB projects in terms of project costs and risks
during construction. It allows optimum usage of the temporary reclamation
provided by CWB for the construction of SCL, so that future temporary
reclamation due to SCL works in the interfacing region can be avoided. On one
hand it reduces the extent of temporary reclamation area required for future
SCL works which in turn facilitates the allocation of resources, on the other hand it as well shortens the duration of temporary
reclamation within the CBTS and hence the impacts on the users of CBTS. Despite
that temporary reclamation additional to that proposed in the CWB project is
required, it would be significantly reduced in terms of size and duration in
comparison to that which would be required if the Protection Works is
undertaken after completion of the CWB.
2.7
As CWB would be
operational during the construction of the SCL, the Project will allow the
future construction of the SCL on both sides of the CWB tunnels without
damaging or unduly affecting the CWB tunnel. The risks of both SCL construction
and CWB tunnel operation are therefore minimized. This arrangement will also
minimize public nuisance and impact to the surrounding environment as it can
reduce the reclamation area for subsequent construction of the SCL after CWB is
completed.
Selection of
Project Scheme
2.8
The engineering
design, location and scale of the Project are governed by the alignment scheme
of the SCL (HUH-ADM). Different alignment options and construction methods of
the SCL (HUH-ADM)
would have direct implication on the design of the Project in various aspects,
including the location and size of works area, extent of dredging and temporary
reclamation, works sequence and phase implementation and even the necessity of
the Project.
2.9
In the alternative alignment schemes and
construction options selection process of SCL (HUH-ADM), potential
environmental impacts and other factors such as geographical and geological
consideration, implementation programme, interface with existing facilities,
operational safety, flexibility and maintenance requirements, constructability,
land acquisition and disruption to the community were considered. The selected
alignment schemes and construction options are considered as the most
appropriate balanced option that has minimised the potential environmental
impacts and can both achieve the needs of the SCL project and benefit to the
public and be constructed with proven technology, at lower costs and less risk
to the programme.
2.10
Under the preferred
option, temporary reclamation will be required to construct the portion of the
SCL tunnel running through the existing CBTS breakwater and inside the CBTS by
cut-and-cover method. This method is
similar to that of the CWB project, which involves cut-and-cover construction,
temporary reclamation and seawalls. It is thereby proposed that the section of
SCL tunnel above the CWB tunnel will be constructed in conjunction with the CWB
tunnel under the Project. The following merits would be achieved by
constructing the SCL Protection Works together with the CWB works within the
CBTS:
·
Use of the temporary
reclamation area provided by CWB to avoid the repeated temporary reclamation at
the interfacing area of the two projects.
·
Minimize the extent
and duration of temporary reclamation required for the construction of the SCL
tunnels.
·
Minimize waste
generation during the construction by avoiding the repeated temporary
reclamation and hence minimize the potential impact to the existing public
fills and landfills in Hong Kong.
·
Minimize disturbance
to the moorings and operations of the typhoon shelter and expedite the works to
avoid prolongation of environmental impacts.
Compliance with
the Protection of the Harbour Ordinance (PHO)
2.11
The PHO Cap 531
recognises the harbour as a special public asset and a natural heritage of Hong Kong to be protected and preserved. Judicial reviews
on other projects have further clarified the legal principles behind the PHO
and have established a presumption against reclamation within Victoria Harbour,
irrespective if the reclamation is permanent or temporary.
2.12
The presumption
against reclamation can only be rebutted by establishing an overriding public need
for the reclamation work. Guidance for addressing the public need for
reclamation (referred to as “the overriding public need test”) is provided in
the Housing, Planning and Lands Bureau Technical Circular No. 1/04 (HPLB TC
1/04). This applies to all reclamations within the boundaries of Victoria Harbour and cogent and convincing
materials are required to support and justify the overriding public need for
reclamation.
2.13
A detailed
examination of the SCL needs and constraints, including an exhaustive investigation
into the need for reclamation for the SCL (HUH-ADM) construction and of
alternative schemes that might do away with reclamation or, at least, minimise
reclamation, has been carried out. A “Cogent and Convincing Materials to
Demonstrate Compliance with the Overriding Public Need Test” (CCM Report for
SCL), which set out the findings of the investigations and the conclusions
regarding the need for reclamation and the minimum extent of reclamation has
been prepared. As detailed in the CCM Report, the three tests in rebutting the
presumption against the reclamation as set out in the PHO have been satisfied:
·
In facilitating the
construction of the SCL and therefore in meeting the overriding public need for
the railway, there is consequently a compelling and present need for the
reclamation in the CBTS and adjacent to Hung Hom
landfalls. All of the reclamation is essentially temporary and will be removed
upon completion of construction, with the seabed reinstated to the original
level.
·
No reasonable alternative
to temporary reclamation is found for constructing the SCL (HUH-ADM) (known as SCL Cross Harbour
Section in the CCM Report).
·
The extent of
reclamation has been determined to be the minimum required.
Construction
Programme
2.14
The
construction of the Project is anticipated to commence in 2012 and be
substantially completed by 2013. The small reclaimed area at the southwest
corner that will be retained to enable the construction of future SCL tunnels
to connect with the proposal SOV will be removed in 2017 under the SCL
(HUH-ADM).
Continuous
Public Involvement
2.15
Public
consultation activities have been conducted to brief the public on the issues
associated with the proposed SCL (HUH-ADM) works in the harbour and seek their
views since the Executive Council approved the further planning and preliminary
design of SCL by the MTR in March 2008. These included public forums,
professional forums and seminars, briefing for and meetings with CBTS users,
presentations to and discussions with District Councils and Harbour-front
Enhancement Committee.
2.16
The
majority of the public supports the SCL and urged for early completion of this
infrastructure. They also opined that
there should be better coordination with the CWB project to minimize disturbance
to the CBTS. Having considered the views of the public, as well as all other
engineering and environmental factors, it is proposed that the Project is to be
implemented as described above.
3.1
The EIA Study was
conducted in accordance with the EIA Study Brief No. ESB–213/2010, following the guidelines on assessment methodologies in the Technical
Memorandum on Environmental Impact Assessment (EIAO-TM). A summary of the
environmental impacts associated with the Project is presented in Table 3.1. The key findings of
the EIA study are summarized below.
Water
Quality Impact
Marine Construction
3.2
The water quality impacts during the marine construction works have been
quantitatively assessed by numerical modelling. Suspended solids were
identified as the most significant water quality parameter during the marine
construction works. Key water quality sensitive receivers identified include
seawater intakes in Victoria Harbour and coral sites in the far field at Green Island
and Junk Bay (Figure Nos. NEX2213/C/331/ENS/M59/501 to 503). The worst-case scenario during the marine construction period, taking
into account the cumulative effects from other concurrent marine works has been
assessed.
3.3
It was predicted that, with the implementation of the recommended good
site practices and mitigation measures, there would be no unacceptable water
quality impacts due to the construction of the SCL Protection Works and due to
the cumulative effects from other concurrent marine construction activities.
The key recommended mitigation measures include:
·
Adopt an approach for temporary reclamation
where temporary seawalls will first be formed to enclose each phase of the
temporary reclamation. Installation of diaphragm wall on temporary reclamation
as well as any bulk filling will proceed behind the completed seawall. Any gaps
that may need to be provided for marine access will be shielded by silt
curtains to control sediment plume dispersion away from the site. Demolition of
temporary reclamation including the demolition of the diaphragm wall and
dredging to the existing seabed levels will also be carried out behind the
temporary seawall. Temporary seawall will be removed after completion of all
excavation and dredging works for demolition of the temporary reclamation.
·
construct temporary seawall closer to the seawater
intakes to protect them from further dredging activities during construction of
the temporary reclamation and temporary seawall further away.
·
Use of closed grab dredger for dredging.
·
Deploy silt curtains to fully enclose the
closed grab dredging during dredging operation.
·
Install silt screens at the cooling water
intakes within the CBTS during the temporary reclamation period.
·
Operate no more than two dredgers for
dredging within the CBTS at any time for SCL Protection Works and ensure the
combined dredging rate for all concurrent dredging works undertaken within the CBTS not greater than
6,000m3 per day throughout the entire construction period
Land-based Construction
3.4
The key issue from the land-based construction activities would be the
potential water quality impact due to the release of sediment-laden water from
surface works areas and discharge of construction site effluent. Water quality deterioration could be minimized
through the implementation of control measures and site practices in ProPECC PN 1/94 “Construction Site Drainage”, such as
sand/silt removal facilities, provision of cover for stockpiles to minimize
site runoff, and proper site drainage.
Noise Impact
3.5
The potential source of noise generation from the construction of the
Project would mainly be the use of powered mechanical equipment (PME) for the
construction activities. Noise Sensitive Receivers (NSRs) located closest to
the Project site boundary were selected as the representative NSRs for the
assessment, including Hoi Deen Court (CH1), Hoi Kung
Court (CH2), Elizabeth House (CH3), Marco Polo Mansion (CH4), Mayson Garden (N11) and Belle House (N13) (Figure Nos. NEX2213/C/331/ENS/M52/501 and 502).
3.6
The construction noise impact on the representative
NSRs have been quantitatively assessed. It was predicted that in the
absence of any control measures, construction noise levels at NSRs N11 and N13
would comply with the EIAO-TM noise criterion of 75dB(A), whereas up to 9dB(A) exceedances were predicted at NSRs CH1 to Ch4. As such, noise mitigation
measures are considered necessary.
3.7
Mitigation
measures including good site practices, quieter plant and movable noise barrier
were recommended to reduce the noise levels so as to meet the EIAO-TM noise
criterion. With the recommended
mitigation measures in place, noise levels due to the Project at all representative NSRs were
predicted to range from 60 to 73 dB(A), in compliance with the EIAO-TM noise
criterion.
3.8
Potential cumulative noise impacts with concurrent
project in the assessment area were considered and no adverse impacts were
anticipated.
Construction
Dust Impact
3.9
Potential dust
impact associated with the construction of the Project has been quantitatively
assessed. A total of 6 representative ASRs were identified for the construction
dust assessment, including World Trade Centre (CHA1), Sino Plaza (CHA2),
Highland Mansion (CHA3), Royal Hong Kong Yacht Club (CHA4), Police Officers
Club (CHA5) and Riviera Mansion (CHA6) (Figure Nos. NEX2213/C/331/ENS/M60/501). Potential sources of dust impact arising from the Project would
include temporary seawall construction, filling, installation of diaphragm
walls, excavation, placing a reinforced concrete tunnel box and removal of
temporary reclamation.
3.10
Under the
unmitigated scenario, the predicted cumulative maximum hourly and 24-hour
average Total Suspended Particulates (TSP) levels at most of the representative
ASRs would exceed the EIAO-TM and AQO TSP criteria. For the annual average TSP levels, exceedances
of the AQO criterion (80 µg/m3) were
predicted at ASR CHA5.
3.11
In order to alleviate the dust impacts, proper dust
mitigation measures were proposed, including watering once every working hour on temporary reclamation area of the
Project, covering/paving the retained area at the southwest of temporary
reclamation and the implementation of good site practices. With the
implementation of the recommended dust mitigation measures, the predicted
cumulative maximum hourly, daily and annual TSP levels at all representative
ASRs would comply with the criteria in EIAO-TM and AQO. No adverse dust impacts
on the ASRs in the vicinity of the construction sites were anticipated.
Waste
Management Implications
3.12
Different types of
potential wastes likely to be generated by the Project have been identified in
this EIA Study. Construction and Demolition (C&D) materials (from
construction of railway tunnel structure and relocation of temporary of RHKYC jetty),
sediment, general refuse (from workforce) and chemical waste (from maintenance
of construction plant and equipment) would be generated during the construction
phase. 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 would not be expected.
3.13
Reduction measures
have been recommended to minimise the amount of materials generated in the
Project. Approximately 14,400m3 of inert
materials and 300 m3 of non-inert materials would be generated
during the construction phase of the Project which would be reused (i.e. other
concurrent projects) as far as practicable before off-site disposal. Opportunities in minimisation of generation
and maximisation of reuse would be continually investigated during the
construction phase. The remainder of
materials would be disposed to designated outlets.
3.14
The total volume
of dredged sediment generated from the Project is estimated to be approximately
38,200m3. Based on the results of the chemical and biological
screening, approximately 9,000m3
sediment is suitable for Type 1 – Open Sea Disposal, 18,700m3
sediment requires Type 2 – Confined Marine Disposal and 10,500m3 sediment
requires Type 3 – Special Treatment/Disposal in accordance with Environment,
Transport and Works Bureau Technical Circular (Works) No. 34/2002 - Management
of Dredged/Excavated Sediment (ETWB TC(W)
No. 34/2002).
3.15
It is proposed that
the handling method of dredged Type 3 sediments should adhere to the CWB project under which geosynthetic
containment would be employed as disposal method. The sediment
should be sealed in geosynthetic containers and
disposed of at the designated contaminated mud pit. The pit would be subsequently capped thereby
meeting the requirements for fully confined mud disposal.
3.16
With the
implementation of the recommended mitigation measures and in accordance with
the requirements of ETWB TC(W) No. 34/2002, no adverse environment impacts would be expected from dredging,
transportation and disposal of marine sediment.
