In 1999, Lok Ma Chau Crossing carried
an average daily flow of 18,000 vehicles (two-way). Based on the Crosslinks
Further Study and the assessment of Transport Department, the total
cross-boundary traffic is predicted to increase at an average rate of 9% per
annum in the coming years before the opening of the Deep Bay Link and the Sheung
Shui-Lok Ma Chau spur line. However, Lok Ma Chau Crossing, being situated on
the preferred route of cross-boundary traffic, is envisaged to be heavily used
in the longer term. While the road system of Lok Ma Chau Crossing will be
improved in stages to cope with the projected traffic growth, capacity
deficiency is envisaged in the future at San Tin Interchange.
According to Transport Department’s
assessment, the design flow/capacity ratios of the two approaches to San Tin
Roundabout from San Tin Highway slip road and Fanling Highway slip road will
exceed the allowable capacity in 2011. As such, improvements by means of two
elevated roads are required to segregate the cross-boundary goods vehicles in
order to relieve the traffic queues in the existing San Tin roundabout.
The two elevated slip roads are a
Designated Project (the Project) under Schedule 2, Part I A.8 of the
Environmental Impact Assessment Ordinance (EIAO) (Cap. 499) and require an
environmental permit under the EIAO for its construction and operation.
An Environmental Impact Assessment
(EIA) Study has been undertaken for the Project to provide information on the
nature and extent of potential environmental impacts arising from the
construction and operation of the proposed Project, and to contribute to
decisions on the overall environmental acceptability of the Project.
The EIA provided a detailed assessment
of the potential environmental impacts associated with the Project, in relation
to the issues specified in the EIA Study Brief No. ESB-092/2002, including
noise, air quality, water quality, waste management, ecology, fisheries,
cultural heritage, landscape and visual, and land contamination.
The proposed Project is located at the
current San Tin Interchange in the North-West New Territories. The two proposed elevated slip roads from
westbound Fanling Highway and eastbound San Tin Highway will merge to form a
4-lane carriageway and then connect to San Sham Road leading to the existing
vehicle holding area at the Lok Ma Chau Boundary Crossing. The preliminary layout of the Project is
shown in Figure 2.1.
The main scope of this Project as
defined in the EIA report will comprise:
provision of two elevated 2-lane slip roads of totally about 1.4 km in
length from the westbound Fanling Highway and northbound San Tin Highway which
will merge to form a 4-lane carriageway and then connect to San Sham Road
leading to the existing vehicle holding area;
provision of two at-grade slip roads to connect Kwu Tung Road and
Castle Peak Road to the elevated slip roads and San Sham Road;
provision of a local widening of the existing Castle Peak Road with a
box culvert extension;
realignment of the at-grade existing slip roads connecting Castle Peak
Road and San Tin Highway; and
provision of a bridge crossing the San Tin Eastern Main Drainage
Channel (EMDC) and realignment of the EMDC maintenance access road to connect
the existing access track to Castle Peak Road.
The construction of the Project is
scheduled for commencement in April 2005 for completion in March 2007.
environmental impacts associated with the construction
and operation phases of the proposed Project are summarized below.
The assessment results indicated that
noise mitigation measures would be required to abate the construction noise
impact at village houses near San Tin Highway and Kwu Tung Road and Tun Yu
School. With the adoption of the quiet
equipment and movable noise barriers, all noise sensitive receivers (NSR) would
be protected against adverse noise impacts from the construction of the
The traffic noise assessment indicated
that impact from the new roads (the proposed slip roads and the proposed
section of Castle Peak Road to be widened) on all existing and planned NSRs
would be within the EIAO Technical Memorandum noise criteria with the
implementation of the recommended noise barriers. Hence, adverse noise impact from the proposed project would not
The key issue in terms of water
quality would be related to site formation and foundation works for the
construction phase. There are no
fishponds within close proximity of the site boundary. Mitigation measures to control runoff and
drainage from the works areas were recommended to minimise construction
run-off. Proper site management and
good housekeeping practices were also recommended to ensure that construction
wastes would not enter the nearby nullahs.
With the implementation of these recommended mitigation measures,
unacceptable impacts on water quality would not be anticipated.
Wastes generated by the construction
activities would include C&D materials from the foundation works, general
refuse from the workforce and chemical waste from any maintenance of
construction plant and equipment.
Provided that these waste arisings are to be handled, transported and
disposed of using the recommended methods and that good site practices are
followed, adverse environmental impacts would not be anticipated.
Direct impacts to terrestrial habitats
and species resulting from the Project would be limited to the loss of small
areas of low value habitats. No species or areas of conservation interest would
be affected. Limited indirect impacts
to wildlife resulting from construction phase disturbance have been predicted.
Disturbance to the high ecological value fishponds north and north west of the
works site are expected to be negligible, given the significant separation
between the nearest ponds and the proposed works areas. Overall, potential ecological impacts
resulting from the Project were found to be minor and acceptable.
The assessment area has only a very
small area (approximately 1 ha) of active fish pond, none of which was located
along or in close vicinity to the proposed slip roads. The assessment indicated that none of the
fish ponds would be directly lost or indirectly affected by the Project. Therefore there would be no impact to pond
aquaculture fisheries resources or operations.
The assessment area was determined to
contain no archaeological sites or areas of archaeological potential. The impact assessment showed that there
would be no adverse impacts to any of the recorded built heritage features and
graves, therefore, no mitigation measures would be required.
The landscape and visual impact
assessment indicated that no significant impact would occur during construction
and operation stages. The disturbance to existing road-side trees,
which amount s to
330 out of the total 1146 number of trees ,would either be transplanted or compensated in the form of advance planting
to the construction stage. The disturbed traffic corridor ( O.277 ha.) and industrial/utility (0. 2 ha.) is man-made with low sensitivity to change. The Project would result in negligible
landscape impact and slight adverse visual impact, with adoption of mitigation
The landscape mitigation measure would
minimize any adverse impacts. It is
predicted that the proposed improvement works would have limited landscape and
visual impact, and considered as “acceptable with mitigation measures”. The extent and location of the recommended landscape mitigation measures
at both construction and operation stage is illustrated in the Landscape Master
It was identified that two areas
within the project boundary (existing open storage area at the section of
Proposed Slip Road B near existing San Tin Interchange and existing open
storage area at the southern portion of Slip Road H) appeared to be potentially
contaminated. Based on the available
information, the potential of land contamination impact at the Study Area was
It was recommended that land
contamination assessment be conducted at the identified areas prior to the
commencement of site clearance / construction works. During the construction phase, mitigation measures should be
implemented in order to minimize the potential health impact on the
An environmental monitoring and audit
programme was recommended for construction noise and water quality. Site inspection/audit was also recommended
to check the implementation of the noise, air quality, water quality and waste
management mitigation measures during the construction phase. Details of the programme are presented in a
separate Environmental Monitoring and Audit Manual.
The findings of the EIA have provided
information on the nature and extent of potential environmental impacts arising
from the Designated Project element of the Improvements to San Tin Interchange
project. The EIA Study has predicted
that the Project, after the adoption of appropriate mitigation measures, would
comply with all environmental legislation and standards, with no adverse
residual impacts. An environmental
monitoring and audit programme has been recommended to monitor the
implementation of the mitigation measures and to ensure compliance with