Consultancy Agreement No.
Modifications to MTRC TST Station
Environmental Impact Assessment
Mass Transit Railway Corporation Limited
MTR Corporation Limited (MTRCL) proposes
to modify the existing MTRC Tsim Sha Tsui (TST) Station in the form of a
southward extension, and provision of an associated pedestrian subway along
Nathan Road. Figure A shows the
location of the project site. The
proposed structure will be located underground and no new ventilation shafts
are proposed. It is anticipated that
there will not be any adverse environmental impacts associated with the
operation phase of this project.
The proposed modifications to TST
Station is regarded as a “material change” to an exempted project under Section
9(4) of the EIA Ordinance (EIAO). MTRCL
submitted a Project Profile to Director of Environmental Protection (DEP) on 13
November 2000 to apply for an EIA Study Brief, which was issued to MTRCL after
public inspection of the Project Profile.
The Objectives and Scope of the EIA Study are described in the EIA Study
CH2M HILL (China) Limited has been
commissioned by MTRCL to carry out an EIA for the proposed modifications to MTR
TST Station. The EIA Team is
independent from the MTRCL’s Engineering Design Consultants, with the MTRCL’s
Environmental Manager providing the necessary interface between them to ensure
that the design and construction method have taken into account the potential
environmental impact and sufficient mitigation measures are properly identified
for inclusion into the construction documentation.
Implementation of the proposed Mody
Road Link as part of the KCRC East Tsim Sha Tsui (ETS) Station requires the
relocation of the plant rooms and station accommodation of the TST Station
located near the Nathan Road – Mody Road junction. Increased pedestrian flows
as a result of the proposed interchange will also result in increased demand on
public area within the station for passenger circulation, and additional space
for station accommodation and larger plant rooms to cater for increased demand
for electricity and other utilities.
Besides, as identified by a pedestrian
forecast study, provision of the Mody Road Link will not be sufficient to cope
with the demand of the passengers using the MTR/ KRC railway interchange. The need to provide an additional pedestrian
subway link at Nathan Road to complete the critical “missing” length of the
subway network was identified. The
proposed “Nathan Road Link” will serve the passengers as a direct and
convenient route between the interchange stations in addition to the “Mody Road
Link”. It was predicted in the
pedestrian forecast study that the proposed Nathan Road Link would be
especially attractive to the passengers using the front half of KCR trains.
Modifying the existing TST station in
the form of an approximately 80m concourse extension to the south of the
existing station will not only provide extra space required for accommodation
of the plant rooms and back-of-house accommodation at the existing TST Station
displaced by the “Mody Road Link”, but will also reduce the length of the
pedestrian subway at Nathan Road linking the station with the Middle Road Link
to approximately 30m only as illustrated in Figure B. No other alternative design options were identified that could
provide such integrated design to connect the existing TST station with the
planned Middle Road Link.
Preliminary options on the design of
the Southern Extension and associated Nathan Road Link were developed by the
Engineering Design consultants and discussed with the Government since August
2000. The preliminary design was
further developed into a “Preferred Option” as shown in Figure C, which
involves an approximately 80m southern concourse extension and an associated
30m long subway link along Nathan Road.
Figure D and E illustrates the relationship of the southern extension to
the existing bored Tsuen Wan Line tunnels.
Use of bored tunnelling technique and
cut-and-cover technique were identified to be the available methods for the
construction works and were reviewed.
Use of bored tunnelling technique in the construction project has not been
identified to be technically feasible for the following main reasons:
shallow depth of the excavation works involved, taking
into account the vertical alignment of the existing concourse which
predetermines the level of the proposed station extension;
presence of the Tsuen Wan Line tunnels beneath the work
area which must not be affected by the works; and
vary stratigraphy of the site area as identified from
site investigation works which will create significant difficulty for bored
Use of cut-and-cover technique is
identified to be technically feasible due to its simplistic nature. The potential environmental dis-benefits
associated with noise and dust emission can be avoided and mitigated by undertaking
the bulk excavation activities under a road deck, phasing and sequence of
construction activities associated with the site clearance and temporary deck
construction, as well as implementation of sufficient dust and noise mitigation
measures during the execution of the construction activities.
The construction programme and
construction sequence has been formulated with a target to minimise the impact
from the construction works on the environment and traffic as a high project
objective. A preliminary construction
programme is presented in Figure F.
The construction works will commence
with removal of the existing median strip.
The existing concrete road pavement will be demolished in stages on a
lane-by-lane basis to minimise impact on traffic movement. Existing utilities lying under Nathan Road
would be diverted only when necessary and would be hung above the underground
excavation site instead if possible such the construction period and hence the
associated temporary disturbance can be minimised.
Temporary piles will be installed for
reinstating the traffic lanes and footpath with decking. As shown in the preliminary programme, a
complete road deck flush with the existing road surface will be built
ultimately to carry Nathan Road traffic while underground excavation works are
Excavation will be carried out beneath
the deck proceeding layer by layer with regular monitoring of Tsuen Wan Line
tunnels integrity. The deck will be removed after the completion of the
underground works, and the road and utilities reinstated using again a
lane-by-lane progressive approach.
The key environmental issues associated
with the proposed TST Station modifications are identified to include:
Construction Noise Impact;
ii. Potential Construction Dust
iii. Construction Waste
The extent of the potential construction
phase impact, through transient, has been identified through the EIA Study and
sufficient environmental mitigation measures identified to alleviate the impact
to acceptable levels. No key
environmental issues were identified to be of concern during the operational
phase of the proposed modifications.
in the vicinity of the work area are mostly hotels that are provided with
central air conditioning and do not rely on openable windows for ventilation. These include, on the western side,
Peninsula Hotel, Kowloon Hotel and Hyatt Regency Hong Kong Hotel and, on the
eastern side, Sheraton Hotel, Imperial Hotel, and Holiday Inn Hotel. Commercial buildings situated in the
vicinity of the work area include
Shui Hing House, Alpha
House and Oterprise Square. Chung King
Mansions situated to the east of the work area is mostly occupied by commercial
uses and hostels equipped with window-type air conditioners. At ground level, there are shops along both
sides of Nathan Road. All landuses in
the vicinity of the work area are zoned as “Commercial” in the Outline Zoning
Given the location of the site and the
need to maintain full traffic on Nathan Road, the construction works will only
proceed on a lane-by-lane basis. Given
the limited work area, the number of Powered Mechanical Equipment (PME)
involved in each stage of construction activities will be limited. The construction phasing will in itself
provide some noise mitigation.
Construction noise is controlled under
the Noise Control Ordinance (NCO) which prohibits the use of PME during the
restricted hours (7 p.m. to 7 a.m. on normal weekdays and any time on a public
holiday, including Sunday) without a valid Construction Noise Permit (CNP)
granted by the Authority. The criteria
and procedures for issuing a permit are specified in the “Technical Memorandum
on Noise from Construction Works Other than Percussive Piling”.
Noise generated the construction works
other than percussive piling during the non-restricted hours (i.e. 7 a.m. to 7
p.m. on weekdays other than general holidays) was the focus of the study. The daytime noise assessment criteria are
set out in Table 1B in Annex 5 of the Technical Memorandum issued under the
Based on the phased construction
programme, a reasonable, preliminary PME inventory has been developed by the Project
Engineering Design Consultant for the construction noise impact study. While it
is expected that the future appointed Contractor may propose a different PME
inventory, the quantitative assessment based on this feasible inventory will
allow the potential noise problem be realised and that practicable and
sufficient noise mitigation measures are derived and planned at this early
stage. The Contractor will be required
by MTRCL through specific contract specification to provide and implement
sufficient direct noise mitigation measures based on the recommendation to
achieve the acceptable noise levels at the nearby NSRs.
The results from quantitative
assessment demonstrated that with the progressive use of a combination of
various practicable noise mitigation measures, the construction noise impact on
the nearby NSRs can be mitigated to acceptable levels. The practicable noise mitigation measures
Ø Use of quiet PME with lower Sound Power Level;
Ø Erect temporary noise barriers and machinery enclosure;
Ø Provide Noise Enclosure at the Traffic Deck Opening retained as
entrance to the underground work area and for exporting of excavated material;
Implement good site practice and noise
To mitigate the noise impact from the
installation of piles, a cantilever noise barrier of sufficient height erected
between the work area and Chungking Mansions was identified to be
required. A schematic drawing showing
the preliminary design of the cantilever noise barrier is shown in Figure
G. On the other hand, when underground
excavation works are carried out underneath the proposed road deck, an acoustic
enclosure is recommended to be provided at the deck opening retained for the
exportation of excavated material.
Figure H shows the preliminary design of the noise enclosure at the deck
opening. Potential cumulative noise
impact on the same NSRs arising from concurrent construction activities for the
TST Station modifications and KCRC East Rail Extension – Hung Hom to Tsim Sha
Tsui was evaluated, and was not
identified to be a concern.
MTRCL will require the appointed
Contractor to implement sufficient direct noise mitigation measures. Implementation of the recommended noise
mitigation measures by the Contractor will be checked by a regular
environmental monitoring and audit programme.
The key air quality issue of interest
during the construction phase of the project is fugitive dust emission. Dust emission will mainly occur during the initial
construction period when construction activities are carried out before the
road deck is constructed.
Potential dust impact associated with
material handling and excavation has been assessed quantitatively using the air
quality model “Fugitive Dust Model” (FDM).
Hourly meteorological data for a whole year has been inputted into the
air quality model to give the worst case maximum 1-hour and daily Total
Suspended Particulate (TSP) concentrations at various representative assessment
points. The modelled TSP concentrations
were compared with the 1-hour and daily TSP limits of 500mg/m3 and 260mg/m3
respectively after the summation of the background TSP level. The assessment results indicated that the
mitigated dust level at the nearby Air Sensitive Receivers (ASRs) will satisfy
the air quality criteria.
In accordance with the requirements
stipulated in the Air Pollution Control (Construction Dust) Regulation,
sufficient dust mitigation measures shall be implemented to minimise the dust impact
to within acceptable levels. Various
forms of practicable dust control measures, including frequent watering and
enclosure of dust emission sources as stated in the regulation have been
highlighted in the EIA for implementation by the Contractor.
Implementation of sufficient dust
control/ mitigation measures will be checked by an Environmental Monitoring and
Audit (EM&A) Programme to be carried out by the Environmental Team. This will allow the Contractor to react
immediately and take action to increase the level of dust mitigation measures
should unacceptable TSP concentrations be monitored.
Construction waste management impact from the execution
of the proposed station modification has been assessed. Given the limited scale of the project,
generation of a large quantity of construction waste is not expected.
It is preliminary estimated that a daily quantity of some
100m3 of excavated material on average would be generated from the
construction site, giving an estimated total quantity of 12,000m3. The excavated material is expected to be the
only major source of Construction and Demolition (C&D) Material, which will
be inert and suitable for reuse in public filling areas or other reclamation
sites. The amount of non-inert C&D
waste is expected to be insignificant and will be disposed of to landfill as
far as practicable. The possibility to retain some of
the excavated material generated onsite for subsequent reuse as backfill
material after the completion of the station box and subway construction was
evaluated but found impracticable given the very limited work area available,
the potential environmental nuisance associated with the storage of excavated
material for a significant period of time, and considering the quality of the
excavated material in satisfying the required engineering requirement for the
works. Nevertheless, the Contractor
will be allowed and encouraged to consider offsite reuse opportunities of the
excavated material before consideration should be given to disposal option at
public filling areas.
To ensure the appropriate handling of
construction material and waste, the Contractor shall implement a Waste
Management Plan (WMP) as recommended and detailed in the EIA report.
The proposed TST Station Modifications
will not only provide sufficient space for the accommodation of the plant rooms
and station accommodation displaced by the KCRC Mody Road Link, but also
complete a critical missing length of subway network to establish an effective
interchange between the TST Station and ETS Station. Implementation of the project will encourage the increased use of
the railway system by the public which is an environmentally preferred mode of
transportation in terms of air quality resulting in less exposure of the public
to road traffic emissions.
An Environmental Impact Assessment
(EIA) has been conducted to address all key environmental issues associated
with the proposed TST Station Southern Extension and associated pedestrian
subway at Nathan Road. The assessments
were carried out based on the requirements of the EIA Study Brief (Brief No.
ESB-063/2000) issued by the Authority.
An appropriate design and alignment has
been adopted such that upon completion of the permanent works, there will not
be any new structures associated with the TST Station Modifications will may
pose an environmental impact on the surrounding sensitive receivers. Adopting a southward concourse extension at
Nathan Road will also minimise the length of the associated pedestrian subway
leading to the Middle Road Link to serve the public.
The key environmental issues assessed
include potential construction dust impact, construction noise impact and
construction waste management.
Mitigation measures have been identified and recommended, where
necessary, to alleviate all identified environmental impact to acceptable
levels. Implementation of sufficient
environmental mitigation measures will be checked through a proposed
Environmental Monitoring and Audit Programme.
Other environmental factors including
water quality, ecological and archaeological/ cultural heritage, landscape and
visual issues have also been reviewed and confirmed not to be key concern.
In the presence of the proposed
mitigation measures, implementation of the proposed TST Station southern
extension and associated pedestrian subway link on Nathan Road is considered feasible
from an environmental perspective and will unlikely pose any unacceptable
environmental impact on the nearby sensitive receivers.