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Chapter Title Page
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1.1 General Layout Plan
In December 2007, the Government gave
the green light for MTR Corporation Limited (MTRCL) to proceed with preliminary
planning and design of the South Island Line eastern section (SIL(E)).
The SIL(E) (hereafter referred to as
“the Project”) will be a medium capacity railway that measures a total
length of approximately
This
executive summary highlights the key findings of the Environmental Impact
Assessment (EIA) for the Project to comply with the EIA Ordinance (EIAO).
The Project
comprises:
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Approximately
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Construction of South Horizons (SOH), Lei Tung
(LET), Wong Chuk Hang (WCH) and Ocean Park (OCP) stations as well as Admiralty
(ADM) interchange station for SIL(E) and Shatin to Central Link (SCL) which
includes station structures and protection works for interchange with SCL;
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Construction of tunnel sections from Admiralty to
Nam Fung Portal and from
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Construction of a viaduct section from
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Construction of a railway bridge alongside the
existing Ap Lei Chau Bridge across the Aberdeen Channel;
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Construction of ventilation shafts associated with
the proposed stations and at
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Construction of a railway depot at the ex-Wong Chuk
Hang Estate site;
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Provision of supporting facilities including site
offices, areas for construction material storage, construction shafts,
temporary barging points and temporary magazine site during construction; and
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Operation of the railway system and the depot.
The Project is classified as a
Designated Project (DP) under Category A “Roads, Railways and Depots” of Part I
in Schedule 2 to the Environmental Impact Assessment Ordinance (EIAO) based on
the following listed categories:
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Item A.2. “A railway and its associated stations”;
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Item A.4. “A railway siding, depot, maintenance
workshop, marshalling yard or goods yard”;
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Item A.7. “A road or railway tunnel more than
A temporary project specific magazine
is proposed to be built at Chung Hom Shan for overnight storage of explosives
that will be used for construction of underground railway facilities. The
magazine will consist of above ground single-storey structures. The explosives
magazine is considered as a DP under Item K.10, Part I of Schedule 2 of the
EIAO.
The future decommissioning of the
explosives magazine is a DP under Item 11, Part II of Schedule 2 of the EIAO
and an Environmental Permit will be required prior to commencement of decommissioning
work.
The proposed SIL(E) will provide a fast,
convenient, environmentally friendly and reliable mode of public transport
between South Horizons and the central business district of Hong Kong, as well
as for cross harbour trips via the interchange with the existing railway
network at Admiralty Station. The new railway line serves not only the resident
population in the Southern District but also tourists heading to or returning
from the major tourist attractions located in the District. Upon completion of
SIL(E) as well as the Shatin to Central Link, the railway network on
Operation of the new railway line will help relieve existing traffic
congestion experienced at critical bottlenecks, including the Aberdeen Tunnel
and as a result journey times on the
There will be no direct emission of air pollutants from operation of the
trains as they are electric powered.
Reduced road traffic and congestion will also lead to improvements in local
air quality.
2.3
Project
Alignment and the Surrounding Environs
The SIL(E) is planned for serving
the Southern District of Hong Kong. The purpose of the project dictates to a
certain extent the appropriate location of the stations and hence the alignment
of the new railway line. The congested urban areas presented many site
constraints on the location of the stations and alignment. After a detailed
evaluation of various alternative options, the preferred network option
involves a medium capacity system for SIL(E) that will run from Admiralty to
South Horizons, via three intermediate stations at
The new railway line will run from
the urban area of Admiralty in tunnel for a route length of about
2.4
Consideration
of Railway Design Alternatives
The alignment design, including key horizontal and vertical alignment
criteria, have to largely follow the railway engineering design requirements.
Design alternatives to reduce environmental impacts, where available, were
identified and analyzed before determining the preferred or refined design.
Amongst other site-specific factors and engineering constraints, the
environmental benefits and dis-benefits of each option during both the
operational and construction phases have been given due consideration as part
of the evaluation of alternatives. Some of the outcomes from the options
evaluation include locating the SOH station at Yi Nam Road to reduce the extent
of cut-and-cover construction; opting for a deeper tunnel alignment at LET to
reduce the noise and visual impacts; adopting the alignment of Aberdeen Channel
Bridge parallel to the existing highway bridges to minimize the visual and
water quality impacts; and locating the Nam Fung Portal at the ex-Canadian
Hospital site instead of at the Wong Chuk Hang Old village site to maximise
separation distance from Nam Fung Road Woodland Site of Special Scientific
Interest (SSSI). Taking into account the prevailing site conditions and
constraints, the viaduct option in the Wong Chuk Hang and
2.5
Proposed
Construction Programme and Sequence
Construction
of the SIL(E) is expected to commence in 2011 for completion in 2015.
MTRCL values the views of stakeholders
and considers that the support of the community is important in the development
of railway extensions. The Corporation together with the Southern District
Council launched a public consultation programme in conjunction with the
preliminary design for the SIL(E) and have continued to communicate with the
local community since the detailed design commenced. The Central &
Western District Council and the Wanchai Council were also consulted about the
proposed arrangement of Admiralty Station and the feasibility of the provision
of the Happy Valley Station. Most of the feedback received during the public consultation were
requests for early completion of SIL(E) to solve the traffic problems.
Suggestions received during the public consultation process in relation to the
further planning of the Project, ranging from issues on station locations and
design, through locations of station entrances, to alignment of the railway
line have been taken into account as far as practicable in the design of the
Project. The public consultation has also allowed the Corporation to give the
community a better understanding of the planning of the Project and
site-specific factors and constraints that have to be taken into account of in
selecting the preferred alignment and design of the Project.
According to the desktop review and
site survey, representative noise sensitive receivers (NSRs) (both existing and
planned) were selected for assessment.
Construction Phase
The main source of noise during the
construction phase would be the use of powered mechanical equipment (PME) in
various construction activities. Considerations have been given to implement
the works in phases as far as practicable in order to reduce the number of PMEs
required on site.
Under the unmitigated scenario for
construction airborne noise, the noise criteria is exceeded by up to
24 dB(A) for nearly all NSRs. To minimise the noise impact, adoption of
quieter PME and the use of noise barriers, enclosures, silencers and noise
insulating fabric have been proposed. With the implementation of the proposed
mitigation measures, the noise impact for the majority of NSRs can be reduced
to below the noise criteria level. Residual construction noise impacts of up to
7 dB(A) are predicted at 11 NSR locations even after exhausting all direct and
practicable mitigation measures. These NSRs are mostly located near Wong Chuk
Hang Depot, Wong Chuk Hang Nullah and at South Horizons with the duration of
exceedance from 2 to 46 weeks. To further mitigate the remaining residual noise
impacts, Indirect Technical Remedies would be considered at the discretion of
the Corporation.
Potential ground-borne noise impact
during the construction phase could be resulted from tunnelling works and the
use of PMEs such as the hydraulic breakers, hand-held breakers and rock drill
for other construction activities. The predicted construction ground-borne
noise levels for the unmitigated ground-borne noise impact shows compliance
with the stipulated noise criteria at all NSRs except at two NSRs near the
works area along LET station, which may experience 8 dB(A) ground-borne noise
exceedance for 3 weeks and 1 dB(A) exceedance for 8 weeks respectively due to
the tunnelling activities. As the quantity of PME to be adopted for works at
this location is already considered as minimum, implementation of good site
practices such as shutting down PME that is in intermittent use between work
periods (or throttled down to a minimum) has been recommended to minimize the
impact as far as possible.
Operation Phase
Operation phase airborne noise might
result from the movement of trains along the viaduct sections and fixed plants from
stations, depot, and ventilation and plant buildings. The operational noise
assessment was carried out based on a Scenario for Existing NSRs and a Scenario
for Existing and Planned NSRs. Under the scenario for Existing NSRs, the
unmitigated railway noise level will exceed the noise criteria by up to 16
dB(A) at six NSRs. Under the scenario for Existing and Planned NSRs, noise
criteria exceedance of up to 9 dB(A) is predicted at most of the Planned NSRs.
To mitigate these potential noise
exceedances, noise barriers/ semi-enclosures were proposed along the viaduct
sections. With the implementation of these mitigation measures, the results
indicate that there will be no exceedance of railway noise criteria for both
existing and planned NSRs.
The maximum permissible noise
emission levels were determined for fixed plant noise sources, taking into
account the types of fixed plant to be located at each station and plant
building and the proximity of NSRs. With fixed plant properly designed to meet
the maximum sound power level specified, no residual noise impacts are
predicted. Nevertheless, noise reduction measures such as locating the fixed
plant in walled plant rooms, implementation of a regularly scheduled plant
maintenance programme, are recommended to limit noise levels as far as
practicable.
Operation ground-borne noise
predictions were carried out at representative ground-borne noise sensitive receivers
located in Admiralty and Ap Lei Chau. The unmitigated ground-borne noise
results show that the noise criteria will be exceeded for one NSR at South
Horizons. With the adoption of inclined turnout and resilient trackform (Type
1a) for the concerned part of the underground section, the predicted
ground-borne noise level from train operation at all ground-borne NSRs would
achieve compliance with the noise criteria for both day / evening and
night-time periods.
Ecological
baseline surveys were conducted between June 2008 and November 2009, which covered
both the wet and dry season, in order to generate the ecological profile in the Project Area. Ten
major habitats were identified in the Project Area, namely, woodland; degraded
woodland; plantation; shrubland; marsh; hillside grassland; drainage channel;
open field; wasteland; and developed area. There are also two recognized sites
of conservation importance, namely
In recognition of the high ecological value of
The surface works of the Project comprises site clearance, cut and
cover, viaduct or railway station construction and associated infrastructure
works, which would result in a permanent habitat loss of about 10 ha, of which
over 70% is developed area of low ecological value. However, the impact of
habitat loss for the project overall is not considered to be significant due to
the limited ecological value of the majority of habitats, while the loss of
woodlands of relatively higher ecological value are either temporary, or
insignificant due to their fragmented profile, isolated location and limited
size. Similarly, impacts to fauna communities are generally considered to be of
low significance except for the ardeid night roost location at Wong Chuk Hang
Nullah.
Where possible, effort would be given in the detailed design to minimise
the habitat loss. Temporarily disturbed habitats would be reinstated as far as
possible after the completion of works while habitat compensation in full scale
is recommended for permanent woodland loss. Where floral species of
conservation interest were identified within the proposed project area,
transplanting has been recommended where in-situ preservation is impractical.
The construction of viaduct at WCH would cause an ecological impact to
the ardeids foraging and roosting at the lower section of WCH nullah through
habitat loss and off-site disturbance during construction and operation phase.
Mitigation measures proposed include avoidance of the peak wintering season for
sensitive works such as the pioneer site clearance and tree felling works,
restricting noisy construction activities using PME between sunset to dawn
(ardeid roosting period), replanting of suitable trees, implementation of noise
suppression measures during operation phase and use of coloured panels to
prevent bird collision. With the full implementation of the mitigation measures, the potential impacts to the
foraging and roosting ardeid would be brought to acceptable level, in considering that the Project would not
bring a significant impact on the survival and reproductive success of the
ardeids.
The construction and operation of the proposed magazine site at Chung
Hom Shan would bring a minor disturbance to the neighbouring environment but
with implementation of good site practices the impact would not be significant.
No significant adverse impact on marine ecology is anticipated, as the marine
benthic and coral community at Aberdeen Channel and Telegraph Bay is limited
and of low ecological value, and only small scaled and mitigated dredging works
are involved in the construction of the railway bridge crossing the Aberdeen
Channel, and the marine piling works for the proposed Telegraph Bay Barging Point are also small in scale.
The key water sensitive receivers
identified for the project are seawater intakes, cooling water intakes, typhoon
shelter, nullah and a coral community at
Construction Phase
Dredging / excavation and minor
seawall modification activities for the construction of pier / pier foundation
of the railway bridge at Aberdeen Channel along with the installation and
removal of temporary marine piles at
The main potential water quality
impacts that could arise from land based activities include site runoff and
drainage, wastewater discharge from tunnelling and sewage effluent from the
workforce. With the implementation of good site practices to control runoff and
effluent release such as provision of channels, bunds or sand bag barriers to
re-direct stormwater to silt removal facilities and collection and treatment of
wastewater from tunnelling prior to discharge, no adverse water quality impact
during construction phase is anticipated.
Operation Phase
Water quality impacts may result
from a change to the flow regime and hydrology of the Aberdeen Channel and WCH
nullah due to the railway bridge and viaduct structures and from the discharge
of wastewater from station and depot facilities.
By aligning the pier at centre of
Aberdeen Channel with the pier foundations of the two existing highway bridges
with respect to the flood/ ebb tidal flow directions; adopting a
hydraulically-efficient design for the nullah modification works; and
implementation of recommended drainage and effluent collection and treatment,
no adverse impacts on water quality during operation phase is anticipated.
Spent cooling effluent from chillers
is recommended to be recycled for flushing use as far as practicable, while
runoff, sewage and wastewater effluents from stations and the depot will be
connected to the existing foul sewerage system. Runoff from rail tracks will
also be intercepted and passed through silt traps and oil interceptors. With
implementation of the recommended drainage and effluent collection and
treatment, no adverse impacts on water quality during operation phase is
anticipated.
3.4
Landscape
and Visual Impact
Within the Study Area, there are 12
key landscape resources (LRs) and 12 key landscape character areas (LCAs), with
3 LCAs of high importance. A total of 45 visual sensitive receivers (VSRs) were
selected for the visual assessment, of which there are 10 VSRs considered to
have high sensitivity to visual impacts from the Project. These are mostly
high-rise residential properties around Ap Lei Chau,
Landscape Impact
The main potential impacts on
existing landscape resources are due to the cut and cover tunnelling works;
construction of the stations, depot, viaduct, railway bridge, tunnel portals
and ventilation and plant buildings; and impacts on trees at the proposed works
areas, temporary barging points and magazine site.
Given that much of the proposed
works would be below ground and proposed works areas would be restored
following the completion of the works, most of the landscape resources would
not be significantly
impacted by the Project. However, some proposed surface works and above ground
stations, viaduct, and bridge structures would inevitably require a loss of
trees and vegetation, resulting in a change to the existing landscapes,
particularly at Hong Kong Park, Wong Chuk Hang, Aberdeen Waterfront and Ap Lei
Chau, which at worst case, may experience significant and moderately adverse
impacts under the unmitigated scenario.
A preliminary tree survey found
approximately 5,768 trees within or located very close to the proposed works
areas of the Project, including a few with protected status such as Registered
Old and Valuable Trees (OVTs). Of these, it is estimated that approximately 20%
including the OVTs can be retained and another 8% can be transplanted. A large
number of the trees that need to be felled are of non-native roadside trees
having lower individual ecological and amenity value as well as fast growing
undesirable species colonised the abandoned sites. Compensatory planting
utilising both ornamental and native species will be implemented as mitigation
measures and it is expected that there will be a net gain of trees upon full
establishment of proposed tree planting,
To minimise the potential impacts, a
number of mitigation measures have been recommended during the construction
phase including preservation of existing trees where possible, application of
decorative screen hoarding where practicable, careful design of site lighting
and layout, replanting of disturbed vegetation at the earliest possible stage,
and transplanting of existing trees where practicable. During the operation
phase, measures to mitigate the permanent landscape impacts include
implementation of an integrated design approach to the above-ground structures
with architectural design that seeks to reduce the apparent visual mass of the
facilities, use of natural tones, and responsive lighting design; compensatory
planting with provision of large ornamental trees for roadside and amenity
planting, reinstatement and creation of open space; and implementation of a
sensitive, innovative and responsive design to the proposed viaduct structures
with compatible and extensive tree and shrub planting. Improvements to the
existing landscape will also be made with the restoration of
Visual Impact
The proposed surface works and
permanent structures would have significant impact on VSRs located at Ap Lei
Chau, Tai Wong Ye Temple and along
Mitigation measures to reduce the
visual impact during construction of the Project include preservation of
existing trees where practicable, buffer planting, responsive hoarding, tidy
site management and careful planning of the construction program. With the
implementation of these mitigation measures, the visual impact will be reduced,
but given the scale, complexity and site constraints of the proposed works, the
majority of VSRs will still experience some temporary visual impact.
To minimise the operational visual
impacts resulting from the railway structures, integrated design approach had
been adopted for the above ground structures where practical and the viaduct
and noise enclosure/ barrier structures have been designed as much as possible
to incorporate a softer façade with use of amenity tree and shrub planting beneath
the viaducts. The viaduct design incorporates relevant overseas
experience and adopts appropriate mitigation measures to reduce the visual
impact of the viaduct. The design has been consulted with the Advisory
Committee on Appearance of Bridges and Associated Structures and the Southern
District Council during the design development of the viaduct. Restoration works such as buffer
planting and enhancement works such as the restoration of
In view
of foreseen ground condition and the impracticability in using other
techniques, drill and blasting for rock excavation is required for some
sections along the alignment. To enable a timely delivery of explosives to site
and in order to meet the proposed construction work programme, an Explosives
Storage Magazine (Magazine) is required. A Quantitative Risk Assessment (QRA)
for the storage and transport of explosives has been carried out as per the EIA
Study Brief. A robust site selection process has been undertaken for the
proposed temporary magazine and two
magazine sites have been identified as practicable:
Chung Hom Shan and Shek O. The EIA Study Brief requirement requires the
“selection of the shortest practicable road transport routes to and from the
magazine” therefore Chung Hom Shan has been selected for the
storage of explosives, based on the site selection process and the EIA Study
Brief requirement. The criterion of the EIAO-TM for
Individual Risk has been met. The assessment results show that the societal
risk lies within the As Low As Reasonably Practicable (ALARP) region when
compared to the criteria stipulated in Annex 4 of the EIAO-TM. An ALARP
assessment has been carried out by identifying all practicable mitigation
measures and assessing the cost effectiveness of each measure in terms of the
risk reduction achieved and the cost of implementing the measures. As part of
the ALARP assessment, a list of potential temporary magazine site candidate has
been reviewed and the Chung Hom Shan has been confirmed as the most practicable
site based on the shortest practicable distance to the construction site.
A QRA was also conducted for the construction and operation of those
parts of the project which fall within the Consultation Zone of a Potentially
Hazardous Installation (PHI). The assessment results show that the societal
risk lies within the acceptable region when compared to the criteria stipulated
in Annex 4 of the EIAO-TM. The criterion of the EIAO-TM for Individual Risk is
met.
3.6
Waste
Management Implications
Waste types generated by the
construction activities of the Project would include marine dredged sediment,
C&D material, general refuse from the workforce, and chemical waste from
the maintenance of construction plant and equipment.
The volume of C&D materials to
be generated by the Project would be approximately 1,417,100m3. Opportunities to
re-use materials have been fully considered. An estimated 5,000m3 of
materials would be reused as backfilling materials at section between Lei Tung
and
In view
of the geographic location of the major mucking out points, C&D
material generated at Island South work sites would be transported to temporary
barging points proposed at Telegraph Bay and Lee Nam Road while, C&D
material generated from the Island North work sites would be transported to
temporary barging point at Western District Public Cargo
Working Area, proposed shared use with WIL project.
The
construction workforce will generate refuse with an estimated maximum daily
volume of 2,405 kg that needs to be properly managed and disposed. With the
implementation of good waste management practices on site, this waste can be
effectively controlled and is not anticipated to cause adverse environmental
impacts. Chemical waste will also be generated from the use of cleaning fluids,
lubricants and fuel. Such waste will be handled and stored in accordance with
the Waste Disposal
(Chemical Waste) (General) Regulations to prevent adverse environmental
impacts.
Volume of marine dredged sediment
generated from the Project is estimated to be less than 100m3 and
was classified as Type 2 – Confined Marine Disposal based on the review of the
sediment quantity data. Dredged sediment will be transferred to barges for
subsequent disposal and care will be taken to limit the release of
dredged/excavated sediment into the surrounding water. Typically East Sha Chau mud pits are the
designated disposal site for contaminated sediment and would be suitable for
accepting this type of dredged material.
Provided that these wastes are
handled, transported and disposed of using approved methods and that the
recommended good site practices are strictly followed, adverse waste management
implication is not expected during construction phase.
During the operation phase, general
refuse would be collected regularly and recycling containers are recommended to
encourage recycling. Industrial and chemical waste would be recycled where
practicable and a reputable and licensed waste collector will be employed to
remove the waste. With the implementation of the recommended mitigation
measures, no adverse waste management implication during operation phase is
anticipated.
A land contamination assessment has
been carried out which included a review of historical/ current land uses,
desktop review and site inspection. The results of the assessment indicated
that there was no significant land contamination issue. Moreover, a prudent
approach in further site investigation was adopted and soil sampling was
undertaken. The site investigation results confirmed the findings of the
desktop review. Therefore, no land contamination implication is anticipated.
During operation phase, defined
procedures in handling chemicals for the operation of railway stations and
depot would be implemented as part of the MTRCL’s policy. As such, no land
contamination implication is anticipated.
Potential air quality impacts from
the construction works for the Project would mainly arise from construction
dust generated from excavation, material handling and stockpiling, spoil
removal as well as operation of crushing and barging activities.
Most of the air sensitive receivers
(ASRs) will experience exceedance of the Total Suspended Particulate (TSP)
criterion under the unmitigated scenario. With mitigation measures in place, a
hypothetical Tier 1 screening that assumes 100% active area of construction
site was carried out for short term hourly and daily TSP assessment. The
purpose of Tier 1 screening is to highlight the ASRs where construction dust
may potentially become an issue. The Tier 1 mitigated assessment shows that the
hourly average TSP concentrations will exceed the criteria at 8 ASRs located at
Wong Chuk Hang, and at 2 ASRs for the daily average TSP concentrations. Those
ASRs with exceedance in the Tier 1 screening were subsequently assessed under
the Tier 2 assessment which assumes 30% active works area located in the
closest proximity to each ASR, which is also a very conservative approach. The
results show no further exceedance of cumulative hourly and daily average TSP
concentrations for any ASR. With mitigation measures in place, the predicted
cumulative annual average TSP concentrations would also fully comply with the
TSP criterion stipulated in EIAO-TM and Air Quality Objectives (AQO).
Mitigation measures specified in the
Air Pollution Control (Construction Dust) Regulation and specific dust control
measures have been recommended. These include regular water spraying on
access roads, exposed earth and during handling of dusty materials; wheel
washing; paving access roads; covering stockpiling area; and enclosing stone
crushing facilities and concrete batching plant. With the implementation of
dust suppression measures, the predicted cumulative hourly, daily and annual
average
During the construction phase,
direct and indirect impacts to cultural heritage resources may occur as a
result of demolition, groundborne vibration from tunnelling activities or damage
from contact with construction equipment and machinery.
Archaeology
The baseline archaeological study
indicated that there were no known archaeological sites located within or in
close proximity to the proposed alignment and works sites. However, some proposed
works sites at Admiralty and Wong Chuk Hang were evaluated as having some
archaeological potential. With the implementation of archaeological watching
briefs for works sites at
Built Heritage
A desktop literature review and
field surveys were undertaken to establish built heritage baseline conditions.
Two
With the implementation of
mitigation measures including controlling the vibration levels from the
tunnelling works as well as providing protective covering or buffer zone to
non-graded built heritage resources in Wong Chuk Hang, no adverse impacts on
the cultural heritage resources in the study area during both construction and
operation phases is envisaged.
An environmental monitoring and
audit (EM&A) programme to check the effectiveness of the recommended
mitigation measures and compliance with relevant statutory requirements would
be implemented.
The proposed key EM&A
requirements include noise and dust monitoring at designated monitoring
stations during construction phase; water quality monitoring during the course
of marine construction works at Aberdeen Channel to monitor any variation in
water quality from the baseline conditions and identify any exceedance of Water
Quality Objectives at sensitive receivers; and regular site inspections at the
works areas as part of the EM&A procedures to ensure the recommended
mitigation measures are properly implemented.
This EIA study has identified and
assessed the potential environmental impacts that may arise from construction
and operation of the Project in accordance with the guidelines of the EIAO-TM
and the EIA study brief. Based on the results of the assessments, the EIA study
concludes that the Project would be environmentally acceptable and in
compliance with the environmental legislation and standards. With the
implementation of the recommended environmental mitigation measures, no
significant adverse residual impacts from the Project is anticipated. A
comprehensive environmental monitoring and audit programme would be implemented
to check the implementation of mitigation measures and environmental
compliance.