Transport Department (TD) has
reviewed the traffic conditions of Tsuen Wan Road (TWR) near Kwai Tsing
Interchange (KT I/C) and considered that a section of the southbound carriageway
of TWR between KT I/C and Kwai Chung Road (KCR) would deteriorate due to
congestion occurs during peak hours in the future years. TD considers that
there is a need to implement the Project to improve the road section to cope
with future traffic growth.
According to the Traffic Impact
Assessment carried out under this Project, the section of the southbound
carriageway of TWR between KT I/C and KCR is currently operating marginally
above capacity in the morning peak hours and it is envisaged that the
congestion would continue to worsen in the future years. The Traffic Impact
Assessment has confirmed that with the introduction of an additional traffic
lane (i.e. the Project), this section of the southbound carriageway of TWR
would be operating within capacity in both the morning and evening peak hours
in all design years.
The new additional traffic lane
(Bridge H) is a designated project under Item A.8 of Part I, Schedule 2 of the
Environmental Impact Assessment Ordinance (EIAO): “A road or railway bridge
more than 100m in length between abutments”.
In addition, there would be
modification of existing slip road (Bridge G), which however would not cause
any environmental impact likely to affect existing or planned community, or
environmental sensitive uses in the vicinity, in particular it would not induce
adverse noise impact during operational phase in view of the reduced
traffic and hence mitigation measure for Bridge G is anticipated not necessary.
Referring to section 6.1 of Technical Memorandum on
Environmental Impact Assessment Process (EIAO-TM), the modification of existing
slip road (Bridge G) would not be classified as "material"
change" under the EIAO.
AECOM Consulting Services
Limited (formerly URS Hong Kong Ltd or Scott Wilson Ltd) was commissioned by
the Civil Engineering and Development Department (CEDD) to undertake the
Environmental Impact Assessment (EIA) Study of the Project.
To fulfil the future demand and
to prevent traffic congestion in the future during peak traffic flow hours, the
recommended road alignment Option 2A is proposed. An additional southbound lane
(a separated viaduct) is introduced on TWR and connected to the existing lane
on the west side of KCR with design speed of 70 km/hr.
The proposed road works is
shown in Figure 1.1. The basis of design for this proposed
flyover is to utilise the remaining capacity currently available on the two
segregated KCR carriageways.
In addition, a second structure
(approximately 150m long) along the nearside lane of TWR near existing KT I/C
upramp is required to achieve widening at the east side of TWR.
Associated works in the
following areas have been identified:
Existing footbridge NF303 is to
be demolished and be re-provided;
Existing Public Works Regional
Laboratory will be affected;
Existing drainage reserve zone
positioned alongside TWR will be affected;
Existing bus stop outside
subway NS10A is to be relocated; and
Minor modification to the
existing Kwai Chung Road involves removal of the existing planter, breaking and
reinstating Kwai Chung Road with the new road marking.
The potential road improvement
options have been considered under this section. Two improvement options, namely Option 1 and
Option 2, were identified in the EIA Study Brief. Option 1 introduces an
additional southbound lane from KT I/C upramp which connects to the existing
downslope segment of KCR upramp. Option 2 introduces an additional southbound
lane on the west side of TWR and this lane is connected to the existing lane on
the west side of KCR. Another improvement option, Option 3, which is based on
widening along both nearside and offside lanes of TWR, has been identified
under this Project. By improving the road geometry of three options to achieve
a design speed of 70km/hr matching the speed limit on the existing TWR, and to
merge either the KCR upramp or the two segregated lanes on KCR for utilization
of the remaining capacity currently available, Option 1A, Option 2A, Option 2B
and Option 3A have been developed. The
alignments of all options are shown in Figures
2.1 and 2.2.
The road improvement options
are evaluated by assessing different viewpoints including the considerations of
the traffic and operation standards, engineering designs, environmental and
other aspects. Options 1, Option 1A and Option 2B are screened out and
considered as infeasible schemes based on the criteria of compliance with the
weaving requirements, Transport Planning and Design Manual (TPDM) standards and
feasibility assessment on the proposed bridge scheme. Option 3 and Option 3A
are least preferable in the alignment evaluation in view of lager work areas
near the noise and air sensitive receivers, higher costs and longer construction
Option 2A - Separate Viaduct on West Side of TWR (Design Speed
70km/hr) is considered as the recommended road
alignment option. The result is based on the overall ranking of viewpoints
determined. Option 2 is similar to Option 2A except the design speed and the
width of the bridge. The evaluation shows Option 2A may have better air quality
under a higher vehicle speed scenario during operation phase.
Construction of the Project under
the recommended road alignment Option 2A shall be commenced tentatively in 2018
and complete in 2021.
The EIA process provides a
means of identifying, assessing and reporting the environmental impacts and benefits
of the project. It is an iterative process that has been followed in parallel
with the design process to identify the potential environmental effects of
various design options, and develop alternatives as well as mitigation measures
to be incorporated into the design, construction and operation of the Project.
CEDD has also come up with measures that can avoid some potential environmental
impacts, while others are minimised or mitigated to acceptable levels.
Potential air quality impacts
arising from the construction of the Project would mainly be related to dust
nuisance from excavation, material handling and wind erosion of the site. As no
massive earthworks and excavation works are required during the construction of
the Project, and dust suppression measures as stipulated under the Air
Pollution Control (Construction Dust) Regulation, and good site practices
should be implemented to further minimise the construction dust generated,
significant adverse air quality impact arising from the fugitive dust is not
The potential impacts arising
from the background pollutant levels within and adjacent to the Project area,
vehicle emissions from open road networks and chimney emissions from the nearby
factories were assessed. The results of the operational air quality impact
assessment related to vehicular emissions indicated no exceedance of respirable suspended
particulates (RSP), fine suspended particulates (FSP) as well as NO2 hourly average concentration criterion is
anticipated. Some air sensitive receivers (ASRs) would exceed annual average NO2
concentration limit in air quality objectives (AQOs),
under both “Without Project” and “With Project” scenarios, which was mainly
resulted from the high background pollutants’ concentrations in this district.
Marine emission rather than vehicular emission is concluded to be the major contributor to the high background level in most areas, due to the
pollutants emitted from the Kwai Chung Container Terminal nearby.
Comparison study between the
two scenarios has been conducted. Results concluded that relatively minor
environmental benefits would be contributed by the Project to the existing
environment, which is mainly due to the improvement of traffic flow and
vehicles travelling speed after the implementation of the proposed Project. As
a result, the project is not anticipated in causing any adverse air quality
impact and in fact will bring about improvements in terms of air quality
impacts to the nearby sensitive receivers, as compared to the existing and
future baseline conditions.
Potential construction noise
impacts would be mainly due to road works and construction of noise screening
structures, affecting the noise sensitive receivers (NSRs) in the vicinity of
the work areas. Unmitigated construction noise levels at the representative
NSRs would be in the range of 61 to 81 dB(A). With the
adoption of quiet powered mechanical equipment, movable noise barriers, noise
jackets, mufflers, limiting the number of plants operated concurrently as well
as good site practices, the noise levels at all representative receivers are
predicted to comply with the construction noise standard. The only exception refer to Lai King Catholic
Secondary School (NSR3) and Hong Kong Examinations and Assessment Authority (HKEAA) Lai
King Assessment Centre (NSR9), which exceedance of noise criterion by 2 to 5 dB(A) during examination period in some months would
occur. The Contractor shall liaise with
the school representative(s) to obtain the examination schedule, and to avoid
noisy construction activities during school examination periods to further
minimize the construction noise impact to those NSRs.
In the operational noise impact
assessment, potential traffic noise impact to the identified NSRs within the
300m study area have been evaluated based on the worst case traffic flow in
Year 2036. Referring to section 6.1 of
the EIAO-TM, modification of existing slip road (Bridge G) would not be
classified as “material change” under the EIAO thus only the new flyover,
Bridge H, is classified as a DP Road in traffic noise assessment.
The unmitigated traffic noise
levels at the identified NSRs would range from 55 to 84 dB(A). It was predicted that the traffic noise
levels arising from the Project at some NSRs exceed the EIAO criteria. As a result, direct noise mitigation measures
such as cantilevered noise barriers, vertical noise barrier and low noise road
surfacing have been proposed for the mitigation of adverse noise impact due to
the DP roads. Although the overall noise
levels at these NSRs would still exceed the relevant noise criteria, the
traffic noise contribution from the DP Road to the overall noise levels would
be negligible and the traffic noise levels from the DP Road itself would not
exceed the noise limit with the proposed mitigation measures. Traffic noise impact due to the Project is
therefore insignificant. Noise
exceedances at the representative NSRs, if any, are due to the existing
roads. Figure 3.1 and Figure 3.2
show the location and sections of proposed mitigation measure respectively
while Figure 3.3 shows photomontages
of those proposed noise barriers.
Potential water pollution
sources have been identified as construction site run-off, sewage from
workforce, and potential risk of chemical spillage. Adverse residual impacts would not be
anticipated with the implementation of adequate mitigation measures including
the of the construction site practices in accordance with the Environmental Protection
Department’s Practice Note on Construction Site
Drainage (ProPECC PN 1/94),
provision and management of portable toilets on-site, and preventive measures
to avoid accidental chemical spillages.
During the operation phase, a
surface water drainage system with silt traps and road gullies would
be provided and properly maintained to collect runoff from the roads during
periods of rain. With surface runoff controlled by best management practice and
maintenance of drainage system by Highway Department regularly, no adverse
impact is anticipated.
The Project is likely to result
in the generation of a variety of wastes and require the management and
disposal of Construction and Demolition (C&D)
material, C&D waste, marine sediment, chemical
waste and general refuse during construction. Provided that the wastes are
managed using approved methods and recommended good site practices, no
unacceptable adverse environmental impacts will be envisaged.
The Public Works Regional
Laboratory of Tsuen Wan (Laboratory) under TWR has been identified as a
chemical waste producer, which is a potential contaminated land use within the
project boundary. The land allocatee shall be
responsible for the land contamination assessment of the Laboratory Site and
ensure the Laboratory Site is free from contamination at the expiry of the
government land allocation and therefore any land contamination concern arising
from past activities would have been remediated prior to the construction of
With implementation of good
site practice, land contamination at the Site arising from construction and
operation phases of the Project as road upgrading works is not envisaged. No adverse environmental impacts on land
contamination for the Project are anticipated.
The baseline study identified
16 key landscape resources (LRs), 8 key landscape character areas (LCAs) and 33
visually sensitive receivers (VSRs) that representing four VSR categories.
Their sensitivities were then assessed. The study predicted that in the absence of mitigation
measures during construction, there are potential
landscape and visual impacts for LR2: Tree Planting at Kwai
Chung Road Interchange Area, LCA3: Residential at Lower Level of Lai King Hill,
LCA6: Kwai Chung Road Interchange Area, R5: Lai King
Estate North, R5A: Lai King Estate South, R6: Yin Lai Court, R7: Highland Park,
O4: Polyclinic & Special Educational Services, O5: Lai King Catholic
Secondary School, O6: Ever Gain Plaza, O8: Lingnan Dr. Chung
Wing Kwong Memorial Secondary School, O10: Lai King Assessment Centre, L1: Kwai
Shun Street Playground, T1: Open Storage Area Car Park Users, T2: Pedestrians
travelling on Street Level under Kwai Chung Road Interchange, T3: Commuters on
Tsuen Wan Road/Kwai Chung Road, T4 Commuters at Lai King Bus Terminus and T5:
Commuters on MTR. During operation, without mitigation
measures, potential landscape and visual impacts are also experienced by LR2,
LCA6, R5, O5, T1, T2 and T3.
To mitigate the potential landscape and visual impacts, recommended
mitigation measures during construction phase include decorative screen hoarding,
night time lighting control at construction sites, and re-instating of
disturbed landscape area. Mitigation measures during operation phase include
incorporating various design features such as choices of material, colour and
shape for the carriageway design, using flowering and colourful foliage shrubs
species for roadside planting, and streetscape enhancement.
With implementation of the
recommended mitigation measures, it is anticipated that the potential landscape
impacts of major LR and LCAs (i.e. LR2, LCA3 and LCA6) during construction will
be mitigated to moderately to slightly levels. By Day
1 of operation, all potential landscape impacts will be insubstantial with the
exception of slightly on LR2. By Year 10 of operation, with the establishment
of the shrubs planting and landscape treatment, LR2 will have insubstantial
impact and LCA6 is considered to have slightly beneficial.
Potential visual impacts with
mitigation measures will be mainly insubstantial for the VSRs at a distance
away from the construction site. For those VSRs with close
proximity to the construction works (i.e. R5, R5A, R6, R7, O4, O5, O6, O8, O10,
L1, T1, T2, T3, T4 and T5), the potential visual impacts will be mitigated to
slightly level. By Day 1 of operation, R5, O5, T1, T2 and T3 will experience slightly
impacts. With the establishment of mitigation measures
in the area, by Year 10 of operation, T1 and T2 will have slightly beneficial impact
while all others will have insubstantial impact.
As the works area of the
Project does not fall within 250m consultation zone of the restored Gin
Drinkers Bay Landfill, LFG hazard assessment is considered not necessary. No LFG hazard impact is anticipated.
No cultural heritage resource
was identified within the Assessment Area of the Project. Therefore, no impacts to cultural heritage
are expected to be anticipated during both construction and operational phases
of the Project.
Environmental monitoring and
audit (EM&A) is recommended for construction and operational noise. Regular
site inspection/audit is also recommended for: i)
dust, water quality, waste management and landscape and visual during
construction phase; and ii) implementation of landscaping measures during
operation phase. Details of recommended
mitigation measures, monitoring procedures and locations are included in a
stand-alone EM&A Manual. This will enable the Contractor to obtain early
warning on potential adverse impacts from the works and take necessary action
to reduce impacts in specific areas if the monitoring results are found to be
close to the criteria.
The EIA has been conducted
based on the latest and best available information. The findings of this EIA
have provided information on the nature and extent of environmental impacts
arising from construction and operation of the Project. The EIA has, where
appropriate, identified mitigation measures to ensure compliance with
environmental legislation and standards.
In conclusion, the Project
would comply with the environmental standards and legislation with the
implementation of the proposed mitigation measures during the construction and
operation phases. The EIA has demonstrated that the Project will not result in
any adverse environmental impacts and in fact will bring about improvements in
terms of air quality impacts to the nearby sensitive receivers, as compared to
the existing and future baseline conditions. Environmental monitoring and audit
mechanisms have been recommended for the construction and operation of the
Project, where necessary, to verify the effectiveness of the recommended