3
impact
assessment
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 were
assessed. Results showed that the
predicted air quality at the air sensitive receivers would comply with the Air Quality Objectives.
Construction
Phase
3.3.1
Potential
construction noise impacts would mainly be due to road works, minor slope works, and construction
of noise
barriers. During
normal daytime working hours, except Lakeshore Building and The Church of Christ in China Tam
Lee Lai Fun Memorial Secondary School,
the predicted noise levels at the noise sensitive receivers
in the vicinity of the work site would comply with the construction
noise criteria stipulated in the Technical Memorandum on
Environmental Impact Assessment Process (EIAO-TM). With the implementation of
noise mitigation measures such as the use of quiet powered mechanical equipment,
movable noise barriers and scheduling of
PMEs/construction activities, the noise levels at the noise sensitive receivers would comply with the
EIAO-TM construction noise criteria.
Operation
Phase
3.3.2
The potential road traffic noise impacts have been
assessed based on Year 2024 traffic flow which would be maximum
traffic projections within 15 years upon operation
of the Project. The
noise levels at some noise sensitive receivers are 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 noise sensitive receives
including Tuen Mun Hospital Quarter, Victory Building,
Lakeshore Building and SKH Mung Yan Primary School.
3.3.3
With two sections 6m
high cantilevered noise barrier and low noise material surfacing on widened TMR
section in place, the widened TMR section noise contributions
to the overall noise levels at all representative NSRs would be less than 1.0
dB(A) and the noise levels from this widened section would all be below the
relevant noise criteria, though the overall noise levels at most of the NSRs
would still exceed the relevant noise criteria. However, it should be noted
that such noise exceedances at the representative NSRs are due to the other
existing roads.
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.
3.4.1
Potential sources of water quality impact associated with
the road widening work and construction of noise barriers would be site runoff,
discharges from construction activities and sewage effluent from
workforce. Water quality impacts
from the land-based construction works can be controlled to acceptable levels
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.
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 arisings 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 works.
3.6.1
The potential land contamination impacts in the study area
have been examined. Based on the
findings from the desktop studies and site inspection, no contaminated sites
were identified within/in vicinity of the Project boundary. No adverse
environmental impacts on land contamination for the widening of Tuen Mun Road
at Tsing Tin Interchange are anticipated.
3.7.2
Hazardous scenarios associated with the chlorine storage and
on-site transport in the TMWTW and the respective occurrence frequencies has
been identified and confirmed by reviewing of historical database to ensure
hazards and its respective occurrence frequencies are acceptable for use.
3.7.3
A quantitative risk assessment (QRA) expressing population
risks in both individual and societal terms has been conducted to evaluate the
risk to population in the vicinity of the TMWTW. This assessment considered the future growth of nearby
population and the increase of traffic flow in future due to the opening of the
HK-SWC and DBL.
3.7.5
Recommendations for the construction period are given in
order to ensure that the construction workers in the project site are well
understanding of evacuation procedures when working in the consultation zone of
the TMWTW.
3.8.1
Ecological survey on terrestrial ecological resources for
the Project has been undertaken.
The results of ecological survey identified 4 habitat types within the
Assessment Area comprising woodland, village, developed area and watercourse.
The identified woodland habitat is considered to have low to moderate
ecological value, while all other habitats, village, developed area and
watercourse, are of low value.
3.8.2
One species of fauna of conservation interest, Little Egret,
have been recorded from the active Tuen Mun egretry and the embankment of the
Tuen Mun River Channel in the Assessment Area. The Tuen Mun Egretry was located
in highly urbanized area with existing heavy traffic flow. Although no nesting
or breeding activities of Little Egret was recorded in recent survey, Egretry
Count in 2006 observed that this Egretry was actively utilized by nesting
Little Egret.
3.8.3
No direct impact on ecological important habitats, such as
woodland habitat, would be resulted from the proposed works. The proposed
construction works would only be conducted in the developed area where mainly
comprises of Tuen Mun Road at Tsing Tin Interchange and the partly Castle Peak
Road (San Hui) Park adjacent to and below the Tsing Tin Interchange. These
habitats are considered as low ecological value and support no floral and
faunal species of conservation importance. The impact on habitat loss is
considered as low.
3.8.4
Another key impact is the removal of trees located within
the footprint of the proposed works area. However, as all of the trees are
common and widespread plantation species, the potential impact to the vegetation
is considered low. To minimize direct loss of individual trees, transplanting
and compensatory planting, not less than 1:1 ratio in terms of quality and
quantity, would be provided.
3.8.5
During
the construction phase, potential disturbance impact on nesting and breeding
activities of Little Egret utilising the egretry and water quality impact on
its feeding habitat would be resulted. With the implementation of effective
noise and water quality control mitigation measures, such disturbance impact
would be minimised. In addition, in view of the Tuen Mun Egretry is located in
highly urbanized areas with high level of noise from the nearby existing heavy
traffic flow and availability of alternative similar foraging area along the
Tuen Mun River Channel, potential impact to breeding and feeding activities of
Little Egret is considered as low.
3.8.6
Key operation phase impact is the potential bird mortality
due to the transparent noise barrier for noise impact. With bird-friendly
design of noise barriers, such as using non-glaring and tinted materials,
putting falcon stickers on the transparent panels, the bird collision due to
the noise barrier would be minimized.
3.9.1
Under the proposed development, approximately 1.03ha of
Castle Peak Road (San Hui) Park will be temporarily closed and affected during
the construction stage.
Approximately 0.09ha area of the park will be permanently lost for the
widening of Tuen Mun Road. It is
considered that the residual landscape impact during operation on Castle Peak
Road (San Hui) Park is slight with the implementation of mitigation measures.
3.9.2
Based on broad brush survey, approximately 47 trees will be
affected by the construction of noise barrier, road widening and associated
slope works. None of these are Leisure
and Cultural Services Department Champion Trees or Registered Old and Valuable
Trees. There are no rare species
or endangered specie but common species.
All the trees with high amenity value which are unavoidably affected by
the works will be transplanted where possible. Detailed tree preservation, transplanting and felling
including compensatory planting proposals will be submitted to relevant
government departments for approval in accordance with ET WBTC no. 3/2006.
3.9.3
Impact on Landscape Character Areas (LCAs) during
construction will be primarily due to the construction activities including
associated temporary works for the road widening works and construction of
noise barrier. After
implementation of mitigation measures, there will be moderate residual impacts
on Transportation Corridor LCA and Park Urban LCA. During Operation, all the LCAs will have insubstantial
impacts with the implementation of mitigation measures.
3.9.4
With implementation of mitigation measures
during construction, there would still be some
moderate negative visual impact on the VSRs adjacent or close to the Project.
Residual impacts on VSRs further away the works area would become slight to insubstantial.
3.9.5
Day 1 after the implementation of operation
stage mitigation measures, there would still be slight adverse visual impact on the VSRs which are close to
the Tsing Tin Interchange except R1(Lakeshore
Building, Rich Building, Victory Building, Kim Po Building and Common Bond
Building), GIC (CCC Tam Lee Lai Fun Memorial Secondary School), GIC4 (Kwong Choi Market) and O1 (Castle Peak Road (San Hui) Park) who will experience
moderate visual impact. 10 years after the implementation of mitigation
measures during operation, the residual impacts on all VSRs are insubstantial
except R1 GIC1, GIC4 and O1 who will experience slight
residual visual impact. Overall, it is considered that the residual landscape
and visual impacts of the proposed development are considered as acceptable
with mitigation measures during construction and operation phase.
3.10.1
There are no archaeological resources identified within and
in the vicinity of Project boundary, therefore, cultural heritage impact
arising from the construction and operation phase of the Project is not
anticipated.
3.11.1
Environmental monitoring and audit are recommended for
construction dust, noise and water quality, to check compliance with relevant
statutory criteria and to ensure the effectiveness of the mitigation
measures. Site inspection and
audit are also recommended for waste management and implementation of
landscaping during construction.
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 critical assessment criteria are
approached. The effectiveness of
on-site control measures would also be evaluated through a monitoring
exercise. All the recommended
mitigation measures will be incorporated in an EM&A programme during
implementation.