1.1.1
Tuen
Mun Road Town Centre Section (TMRTCS) is bounded between Lam Tei Interchange in
the north and Wong Chu Road
in the south. This road section is
already heavily used in peak hours.
The general public and members of Tuen Mun District Council have
expressed concerns on potential congestion of TMRTCS after opening of the Hong Kong – Shenzhen Western Corridor and the Deep Bay
Link in July 2007. To address the
public’s concern, HyD have commissioned the Feasibility Study on Traffic
Improvement to TMRTCS in December 2005.
The study recommended dual 3-lane widening of sections of TMRTCS. The
Project is to widen about 1.5km
of Tuen Mun Road
from Yan Oi Square
to Wong Chu Road
Interchange from dual-two to dual-three carriageway and to
construct a 450m
long flyover from Tsing Hoi Circuit to Tuen Mun Road Kowloon
bound. The total road length of the Project is about 1.8km.
1.1.2
Based
on the recommendation of the above Feasibility Study, HyD appointed Maunsell Consultants
Asia Ltd. in May 2007 to undertake the Investigation, Design and Construction
(IDC) of Traffic Improvements to TMRTCS (hereafter “the Project”) and the
associated “Environmental Impact Assessment” .
1.1.3
In the Feasibility Study under
the HyD Agreement No. CE 38/2005(HY), four options have been considered for
traffic improvement of Tuen Mun Road Town Centre Section. The four options include:
·
Option 1
– Sam Shing Hui Slip Road Option: This option
suggested a new interchange constructed at Sam Shing Hui;
·
Option 2 – Tunnel Option: This scheme was initiated
by TMDC members during consultations;
·
Option 3 – Dual 3-lane Widening Option which is
currently; &
·
Option 4 – Dual 3-lane Widening combined with
modified slip road.
1.1.4
Four traffic improvement options under the Assignment were compared and
evaluated against the criteria including traffic benefits, social benefits,
engineering feasibility, land requirement, programme and cost.
1.1.5
In brief, having assessed and evaluated each of these options, the D3
Option was selected as the preferred option of the Project. The recommended
option was presented to the Tuen Mun District Council (TMDC) on 10 November
2006. The TMDC had no objection to the implementation of the recommended option
and reiterated the urgency of the Project. Subsequently, HyD commissioned this
TMRTCS – IDC assignment to carry out the investigation, design and construction
of the TMRTCS Project. Under the IDC stage, the D3 option was further assessed
and presented to the T&TC meeting under TMDC member on 14 September 2007
and was well-received by TMDC. The
location of the Project site is shown in Figure 1.1.
1.2.1
Under Section A.1 of Schedule 2, Part 1 of the Environmental Impact
Assessment Ordinance (EIAO) (Cap. 499), the Project is a designated project and
therefore Environmental Permit is required under the EIAO for the construction
and operation of the Project.
1.2.2
An Environmental Impact Assessment (EIA) has been undertaken to provide
information on the nature and extent of environmental impacts arising from the
construction and operation of the Project and all related activities taking
place concurrently.
1.2.3
This Executive Summary provides a summary of the key findings of the EIA
study, including an assessment of potential air quality, noise, water quality,
waste, ecology, land contamination, visual and landscape impacts from the
construction and operation phases of the Project, and recommendations for
mitigation measures to comply with environmental legislations and standards.
2
Project
Description
2.1.1
The Project involves widening the following sections of TMR from dual-two
carriageway to dual-three carriageway:-
·
Wong Chu Road Section (from Wong Chu Road
Interchange to Tuen Hing Road);
and
·
Tuen Mun Town Plaza Section (from Yan Oi Town Square
to Tuen Hing Road).
2.2.1
The construction of the Project will commence in 2009 and complete by
2012.
3
impact assessment
3.2
Air Quality Impacts
Construction Phase
3.2.1
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.
With the implementation of appropriate dust control and suppression
measures as stipulated in the Air Pollution Control (Construction Dust)
Regulation and good site practices, no adverse dust impact at the air sensitive
receivers would be expected.
Operation Phase
3.2.2
The potential impacts arising from the background pollutant levels
within and adjacent to the Project area, vehicle emissions from open road
networks and the implementation of roadside noise barriers and enclosures were
assessed. Results showed that the
predicted air quality at the air sensitive receivers would comply with the Air
Quality Objectives.
3.3
Noise Impacts
Construction Phase
3.3.1
Potential construction noise impacts would mainly be due to road works and
construction of noise barriers/enclosures and would affect the noise sensitive
receivers (NSRs) in the vicinity of the work site. With the implementation of noise
mitigation measures such as use of quiet powered mechanical equipment, movable
noise barriers and scheduling of some construction activities, the noise levels
at the NSRs except CMA Choi Cheung Kok Secondary School (CMA), Yan Oi Tong
Madam Lau Wong Fat Primary School (LWF), Lui Cheung Kwong Lutheran College
(LCK), Lui Cheung Kwong Lutheran Primary School (LCKP) and CSBS Mrs. Aw Boon
Haw Secondary School (CSBS) would comply with the construction noise criteria
stipulated in the Technical Memorandum on Environmental Impact Assessment
Process (EIAO-TM). It is
anticipated that NSR CMA, LWF, LCK, LCKP and CSBS would expose to noise levels
exceeding the construction noise criterion for school during examination
periods (65 dB(A)) by 1 – 5 dB(A).
To avoid adverse noise impact, it is recommended that the construction
works should be carefully planned during examination period.
Operation Phase
3.3.2
The potential road traffic noise impacts have been assessed based on
Year 2025 traffic flow which would be maximum traffic projections within 15
years upon operation of the Project.
The noise levels at some NSRs were predicted to exceed the EIAO-TM
traffic noise criteria due to both widened TMR section and other existing
roads. Direct noise mitigation
measures on the widened TMR road section were proposed to mitigate the
corresponding noise impacts at affected NSRs where the widened TMR road section
noise contributions to the overall noise levels would be more than 1.0
dB(A).
3.3.3
With the proposed noise mitigation measures in place (Figures 3.1A,
3.1B, 3.1C, 3.2A and 3.2B), the widened TMR road section noise
contributions to the overall noise levels at all representative NSRs would be
less than 1.0 dB(A), except some NSRs at Chi Lok Fa Yuen, Ting Fuk House of On
Ting Estate, Hong King Garden, Tung Wah Group of Hospitals Tai Tung Pui Social
Service Building, JC Place, Harvest Garden and Kam Fai Garden. Eligibility test was conducted to assess
the eligibility of these NSRs for provision of noise insulation works (NIW). The test results showed that these NSRs
were not eligible for provision of NIW.
3.3.4
Monitoring of road traffic noise is recommended to verify the
effectiveness of the mitigation scheme during the first year after road
opening.
3.4
Water Quality
3.4.1
Potential sources of water quality impact associated with the road
widening work and construction of noise barriers/enclosures would be site
runoff, effluent discharges from construction activities and sewage effluent
from workforce. Water quality
impacts from the land-based construction works can be controlled to comply with
the standards of Water Pollution Control Ordinance by implementing the
recommended mitigation measures.
All the effluents and runoff generated from the works areas shall be
treated. No unacceptable water
quality impacts would be expected from the land-based construction
activities. Site inspections should
be undertaken routinely to inspect the works areas in order to ensure the
recommended mitigation measures are properly implemented.
3.4.2
For the operation phase, a surface water drainage system would be provided
to collect runoff from the road during periods of rain, no adverse impact was
anticipated.
3.5
Waste Management Implications
3.5.1
Wastes generated by the construction activities are likely to include
construction and demolition (C&D) materials from the construction works,
general refuse from the workforce and chemical waste from any maintenance of
construction plant and equipment.
Provided that these identified waste 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 anticipated
during the construction phase.
3.6
Ecological Impact
3.6.1
Ecological survey on terrestrial ecological
resources for the Project was conducted.
The results of ecological survey identified seven habitat types within
the Study Area including woodland, shrubland, plantation woodland,
inactive/active agricultural area, town park, developed area/village and
watercourse. The identified
woodland and shrubland habitats are considered to have moderate ecological
value, while the other habitats are considered to have low to moderate value.
3.6.2
No direct impact on ecologically important habitats
would be resulted from the proposed works, which would take up 12 ha of developed area. The proposed construction works would
only occur within the developed area, which is of low ecological value and is
comprised of a section of Tuen Mun
Road from San Hui Sitting-out Area to Kam Fai
Garden. The developed area supports
no floral and faunal species of conservation importance. The impact on habitat loss is considered
to be low.
3.6.3
Little Egret (Egretta
garzetta), a species of conservation interest, has adopted to tolerate a
certain level of pollution and disturbance. It was recorded at the egretry and along
the embankment of Tuen Mun River Channel within the Study Area. Construction and operation of the
Project are not expected to have significant impact on the egretry and bird
population (approximate 270m away) with the implementation of proposed
mitigation measures.
3.6.4
The impact of loss of vegetation through removal of
roadside plantation of common species within the proposed Works Area is not
considered to be ecologically significant.
The loss could be compensated by compensatory planting or
transplantation. Species of choice should be composed of similar native species, and
the felling and planting ratio should be no less than 1:1 in terms of quantity.
3.6.5
Bird collision with the proposed construction of
permanent noise barrier/enclosure could result in bird mortality. With bird-friendly design of noise
barrier/enclosure, such as using falcon sticker,
tinted materials, embedded opaque stripes and superimposed patterns of thin
opaque stripes, the chance of bird collision during operation phase of the
Project would be minimized.
3.6.6
Considering the small scale of proposed
construction works, highly disturbed nature of the Study Area, and with the
proposed mitigation measures in place, including noise mitigation measures and good
site practice, no adverse ecological impacts from the construction and
operation of the Project is expected.
3.7
Landscape and Visual Impact
3.7.1
The
source of landscape and visual impact is mainly due to the provision of noise
barriers and enclosures for the road widening works. Under the EIAO, noise
barriers and enclosures must be provided to mitigate the traffic noise. Such
provisions are supported by the Tuen Mun District Council because the current
noise level due to the existing traffic at TMRTC is high. The provision of
noise enclosures will reduce the noise level to satisfy current standard. The
relevant meetings with TMDC were held on 14 September 2007, 21 September 2007,
19 February 2008, 14 March 2008 and 21 November 2008.
3.7.2
Given
the tight space within the Tuen
Mun Road, the additional lane and provision of
noise barriers and enclosures will cause significant impact on existing trees
along Tuen Mun Road
and such impact is unavoidable. The impact on trees has been consulted with TMDC
and comments on tree treatment proposals will be incorporated in detailed
design of the Project. Approximate 860 trees (out of
approximately 1000 existing trees) will be affected by the construction of
traffic improvement works to Tuen
Mun Road and the proposed noise barriers and
enclosures. Approximately 50% of the affected trees will be transplanted and
approximately 50% will be felled. Many of the affected trees are mature. None
of these are LCSD Champion Trees or Registered Old and Valuable Trees. There
are no rare species or endangered species but common species. Opportunities for tree
compensation within the site boundary and outside the site boundary within Tuen
Mun Town Centre have been fully explored and incorporated in the mitigation
measures as much as possible. Heavy standard and
standard trees will be planted to compensate for the felled trees at 1:1 ratio
in terms of quantity. Advance tree planting is proposed within Tuen Mun Town Centre as soon as
possible and practical to mitigate the loss of greenery during construction and
operation of the Project.
3.7.3
A number of open space and
planting areas in Tsing Sin Park, Yan Oi Tong Circuit, On Tin Estate and Tsing
Hoi Playground will be alienated by the temporary works during the construction
phase. Many of the affected areas during the construction will be reinstated
after the construction work. Approximate 350sqm of open space area (12%) will
be permanently lost in Tsing Hoi Playground and approximate 700sqm of open
space area (14%) will be permanently lost in Tsing Sin Park due to the road
works. The residual impact on these open spaces is slight as only a small
percentage of the overall park or playground will be affected.
3.7.4
To
minimize the visual impact due to the provision of noise barriers and enclosures,
an integrated landscape and engineering design approach has been adopted.
Design measures have been incorporated to minimize the visual bulkiness of the
structure. Vertical greening panels with design theme in area with adequate
sunlight and maintenance access to reflect the local context are proposed. The
green roof for the noise enclosure has been fully explored and proposed where
space for maintenance access is allowed. There are a number of design options
considered for the green roof, vertical facade treatment and colour scheme for
the noise barriers and enclosures. Based on the assessments and considerations
documented in the report, the preferred overall landscape and aesthetic design
treatments on the noise barriers and enclosures is recommended as the proposed
design scheme for the landscape and visual impact assessment.
3.7.5
With
the implementation of the proposed mitigation measures as per the preferred
landscape and aesthetic design treatment, unavoidably, there will still be moderate
residual visual impact on adjacent Visual Sensitive Receivers (VSR) as well as
the traveling VSRs along Tuen Mun
Road due to the blockage of views by the noise
enclosures and barriers and loss of existing greenery. However, with the
thematic design treatment on the vertical facade and green roof treatment with
pattern, it is considered that the residual visual impact has been reduced to a
marginally acceptable level.
3.7.6
In
summary, the provision of the noise barriers and enclosures for the road widening
works is a mandatory requirement under the EIAO and is supported by the Tuen
Mun District Council. With the implementation of the mitigation measures,
including the provision of approximate 11,000sqm vertical green panels with
thematic treatment along the noise barriers and enclosures facade, the
provision of approximate 20,000sqm green roof and the implementation of Tuen
Mun District Planting Scheme, it is believed that the landscape and visual
impact will be brought down to a marginally acceptable level after 10 years.
3.8
Land Contamination
3.8.1
An investigation of the historical / current land uses
in respect of land contamination, including a desktop study and site inspection
was conducted around the TMRTCS.
3.8.2
Based on the site reconnaissance, there has been no potential land contamination concern within the
Project boundary. However, the existing petrol filling station located
outside the assessment area, near the junction of Tuen Hing Street and TMR was identified
as an indirect concern. This petrol filling station has been operated for over
a decade and has potential of land contamination concern resulting from
localised fuel leakage/ seepage. A preliminary
land contamination survey
is therefore
proposed within boundary of the assessment area at the immediate down gradient of the petrol
filling station to determine the baseline soil and groundwater conditions.
3.8.3
Mitigation measures have also been proposed for
handling of the potential contaminated materials as general measures. No
adverse residual impact in respect of land contamination is anticipated if
necessary remediation is carried out at the contaminated areas confirmed by
site investigation.
3.9
Environmental Monitoring and Audit
3.9.1
Environmental monitoring and audit
is recommended for construction dust, construction noise and operational
traffic noise, to check compliance with relevant statutory criteria and to
ensure the effectiveness of the mitigation measures. Site inspection and audit are also
recommended for ecology, water quality, waste management, land
contamination, landscape and visual during construction, and implementation of
landscaping measures during operation.
Details of the recommended mitigation measures, monitoring procedures
and locations are presented in a stand-alone Environmental Monitoring and Audit
(EM&A) Manual. This will enable
the Contractor to have early warning and provide necessary action to reduce
impacts at specific areas if the monitoring results are close to the
criteria. The effectiveness of
on-site control measures would also be evaluated through a monitoring
exercise. All the recommended
mitigation measures would be incorporated in an EM&A programme during
implementation.
3.10
Overall Conclusion
3.10.1 The EIA has been conducted based on the currently 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.
3.10.2 In conclusion, the Project would generally comply with the
environmental standards and legislation with implementation of the proposed
mitigation measures during the construction and operational stages. This EIA has also demonstrated the
general acceptability of the residual impacts and the population and
environmentally sensitive resources in the vicinity of the site would be
protected. Environmental monitoring
and audit mechanisms have been recommended for construction and operation of
the Project, where necessary, to verify the effectiveness of the recommended
mitigation measures.