17.1
This EIA Report has provided an assessment of the potential
environmental impacts associated with the construction and operation of the
Project, based on the preliminary engineering design information available at
this stage.
17.2
The assessment has been conducted, in accordance with the
EIA Study Brief (No. ESB–197/2008) under the EIAO for the Project, covering the
following environmental issues:
n
Ecological
Impact
n
Fisheries
Impact
n
Airborne Noise Impact
n
Ground-borne Noise Impact
n
Landscape and Visual Impacts
n
Cultural Heritage Impact
n
Land Contamination
n
Waste Management Implications
n
Water Quality Impact
n
Air Quality Impact
n
Hazard to Life
n
Landfill Gas Hazard
n
Impacts on the Restored Ngau Tam
Mei Landfill
17.3
The findings of this EIA study have determined
the likely
nature and
extent of environmental impacts predicted to arise from the construction and
operation of the Project. During the EIA
process, environmental control measures have been identified and incorporated
into the planning and design of the Project, to achieve compliance with
environmental legislation and standards during both the construction and
operation phases. The Implementation
Schedules listing the recommended
mitigation measures are presented in Section 18.
17.4
Overall, the EIA study for the Hong
Kong Section of XRL has predicted that the Project, with the implementation of the
mitigation measures, would be environmentally acceptable with no adverse
residual impacts on the population and environmentally sensitive
resources. Table 17.1 summarises the environmental outcomes/benefits that have
accrued from the environmental considerations and analysis during the EIA
process and the implementation of environmental control measures of the
Project. Environmental monitoring and
audit requirements have been recommended, where necessary, to check
on project compliance of environmental legislation and standards.
Table 17.1 Summary of Key Environmental Outcomes / Benefits
|
Area/Issue |
Environmental Outcomes / Benefits and Mitigation Measures |
|
The Project |
The Project comprises the following key
elements: ·
Approximately
26km of underground railway running from the terminus in ·
A
terminus in ·
Seven
tunnel ventilation buildings at ·
Stabling
sidings and maintenance facilities located at Shek Kong (Shek Kong Stabling
Sidings (SSS)) to provide for train stabling, minor maintenance and cleaning;
and ·
An
emergency rescue station (ERS) located next to the SSS. |
|
Environmental/Social Benefits of the
Project |
·
The Project will minimize the travelling time
between Hong Kong and ·
Through this rail link, Hong Kong can be
connected directly with major Mainland cities, such as ·
The provision of the Project will promote Hong
Kong as the gateway to the Pearl River Delta area, further strengthen the
economic ties and cooperation between ·
It is also expected that the Project will create
5,000 employment opportunities during its construction and another 10,000
during its operation. |
|
Environmentally Friendly Design Considered
and Recommended to Avoid Environmental Problems |
·
Ecological sensitive
areas have been avoided to minimize the potential impact during the
preliminary design study. ·
All ·
Different types of
ventilation buildings have been designed for proper provision at different
areas. Low-height ventilation building
has been assigned to the areas which are considered to be sensitive on visual
and ecology. ·
Locations of
ventilation buildings have been carefully selected to minimize the impacts to
the environmental sensitive receivers. ·
The Project alignment
will be constructed underground. Given
the deep underground tunnel, ground-borne train noise impacts would be minor
and could be alleviated, if necessary, to acceptable levels through the use
of low noise trackform. ·
Airborne railway noise
impacts and the need of mitigation measures could be avoided except at SSS
and ERS. Mitigation measures have been
studied to minimize the potential impact from the SSS operation and airborne
train noise to the nearby sensitive receivers. ·
None
of the LCSD Champion Trees or Registered Old and Valuable Trees will be
affected. All the affected trees are common species with an average of medium
to low amenity value. ·
Spoil generated from
the Project will be reused in other projects as much as practicable and transported
to the Mainland as the last resort by barges either for reuse or disposed
of. This arrangement would minimize
the potential impact to the existing public fills and landfills in |
|
Population and Environmentally Sensitive
Areas Protected |
·
With the adoption of
environmentally design mentioned above, major environmentally sensitive
receivers will be protected. ·
Most of the sites of
ventilation buildings will be used as work sites and/or
construction/ventilation shafts during construction phase to minimise the
works areas as well as disturbance to the public and environment. ·
There would not be any
airborne train noise impacts on the noise sensitive uses along 26km alignment
except at Shek Kong as the entire alignment would be in tunnel. |
|
Ecological |
A literature review and
ecological field surveys have been conducted.
Potential impacts on significant ecological resources, such as Wetland
Conservation Area and In these works areas, the
identified habitats are generally of low ecological value, and flora and
fauna recorded are predominantly common species in Potential impacts on
watercourse habitats at the SSS have been minimized, through the use of a
flood bypass and incorporation of ecologically friendly channel features, such
as natural stream bed substrate and vegetated stream banks, into the SSS open
drainage channel sections to provide aquatic habitats for wildlife use. No direct impact to
significant areas nor species of conservation interest are anticipated from
the Project. Potential impacts on
hydrology would be avoided through the implementation of precautionary design
measures during tunneling works to prevent groundwater leakage into the
tunnel and any significant groundwater drawdown. A program will be implemented to monitor
groundwater levels. There would be low
potential indirect construction and operation impacts to habitats and
associated wildlife adjacent to the Project, with mitigation measures such as
hoarding, run-off control, use of non-reflective building facade,
reinstatement of works area, and good construction site practices. Lung Kwu Sheung Tan Marine works would be
conducted to form a berthing area for the barging facility in Lung Kwu Sheung
Tan (LKST). The works have been minimized
and would last for approximately three months involving a small area of
dredging (about No species of
conservation interest were found in the sub-tidal and intertidal marine
ecological field surveys. The LKST
barging point area is not a habitat of high importance for Chinese White
Dolphins and the potential impact to the dolphins and their habitats is
considered to be low. There is no
recent record of horseshoe crabs in LKST, and no significant impact on their
potential habitats due to the proposed works is anticipated. Given the low ecological significance of
the impacted area and with the implementation of precautionary control
measures such as deployment of silt curtain, limited marine ecological impact
is expected. No marine works will be
involved for the seawater cooling system for WKT. The loss of low value sub-tidal habitats
due to replacement of vertical seawall for the intake and outfall seawall
structures would be minimal. Based on
water quality modeling of the operation of the water cooling system,
potential marine ecological impacts would be minor and localized. |
|
Fisheries |
Potential impacts on significant fisheries resources have been
avoided through alignment selection process for the Project. There would be no direct impact to habitat
loss nor disturbance of both active and inactive fishponds and their pond
bunds. Indirect impacts to fishponds
in Marine
Fisheries No
fish culture zones nor important spawning / nursery grounds were identified
in the vicinity of the Project area at the LKST and Tsing Chau Tsai barging
points, and WKT seawater cooling system. There will be no marine works at Tsing Chau Tsai
and |
|
Airborne Noise |
Unmitigated construction noise levels at the
representative NSRs are predicted, which are found to be in the range of 38
to 91 dB(A). Mitigation measures are recommended to reduce the noise
levels to within the EIAO-TM noise criterion, including good site practices,
quieter plant, silencer, movable noise barrier, noise enclosure, noise
insulating fabric, acoustic enclosure and noise insulating cover. After
mitigation, noise levels at most of the NSRs are predicted to comply with the
EIAO-TM daytime construction noise criterion. All practical mitigation
measures have been exhausted and residual impact at some existing NSRs
including SS10, SS11, ML1, NC13, MK1, WK4, WK8 and WK14, which are located in
close proximity to the works areas, is anticipated. Noisy construction works should be avoided
during the examination period to minimise adverse impact to ML1, NC13 and
MK1. Airborne railway noise and associated substantial
mitigation measures has been avoided for an underground railway system,
except at SSS and ERS. The major
source of airborne railway noise is identified as the trains passing through
the ERS in a high speed profile. Sound absorption treatment of 13m high and a
8m high barrier is recommended to be provided for each side along full length
of the ERS and the access road on eastern side of SSS respectively. With the mitigation measures in place, the
airborne railway noise levels at NSRs located in the vicinity would comply
with noise criteria. Noise levels from train movements and trains idling in the
maintenance shed within the SSS will comply with the night-time noise
criteria but exceed daytime noise criteria due to the operation of
maintenance trains. A 5.5m high noise
barrier is therefore required to be provided at the western boundary of SSS
facing Leung Uk Tsuen. Apart from
train operation, maximum allowable sound power level emitted from plant at
the maintenance shed has been predicted.
Acoustic treatment such as partial enclosure and acoustical louvers,
if required, will be provided to ensure that the noise levels at NSRs comply
with noise criteria. With the
implementation of proposed mitigation measures, the fixed plant noise levels
at NSRs would comply with noise criteria.
Predicted noise levels arising from the fixed plant of the Project at
the NSRs located in the vicinity of ventilation buildings and shafts would
comply with the EIAO-TM criteria with proper selection of plant and adoption of
acoustic treatment. |
|
Ground-borne Noise |
Construction ground-borne noise assessment has been
conducted to assess the feasibility of TBM tunnelling construction. Prediction results indicate the TBM and PME
induced ground-borne levels at GBNSRs comply with the EIAO noise limit,
except exceedance predicted at four sensitive receivers due to TBM
operation. It is however anticipated
that the period of exceedance would be about only two or three days, basing
on the TBM daily progress in LMC. An
EM&A programme is recommended to control and monitor the construction
ground-borne level. Where it is possible that the 65dB(A) limit will be
exceeded, scheduling of the works and closely liaison with affected parties
will be conducted to alleviate the impact.
The operation of TBM during restricted hours should be governed by the
control of CNP under NCO. Ground-borne noise levels have been predicted based on the
maximum operation capacity of railway system.
Results of predicted ground-borne noise levels at the GBNSRs indicated
the use of standard resilient baseplates will be sufficient to meet the
stipulated noise criteria. Low noise trackform suitable for high speed railway, such
as IST and Vanguard, has been studied.
To cater uncertainty of the FDL and LSR values, installation of low
noise trackform at the concerned areas has been proposed and would be
implemented to further reduce the ground-borne noise levels. |
|
Landscape and Visual |
The potential landscape and
visual impacts have been minimized and confined to above-ground works. The
key sources of impact during construction stage are from the activities
associated with the construction of the aboveground structures within the
works areas of the Project The key sources of impacts during operation stage are
confined to the proposed aboveground structures located at Mai Po, Nagu Tam
Mei, Tai Kong Po, Shek Kong, Pat Heng, Shing Mun, Kwai Chung, Mong Kok West
and West Kowloon. Potential impacts have been considered during the
preliminary design of the Project to minimize works areas and avoid direct
impacts on significant landscape resources.
Approximately 12,000 trees were
surveyed in broad brush tree survey. These trees were mainly roadside
plantings, farmlands/orchards, shrublands/grasslands and semi-natural
hillside woodland. Around 11,800 trees
would fall within the works area of the Project. Of these, approximately 5200 trees would be
retained on-site, approximately 1,100 trees would be transplanted and about
5,500 trees would be felled. None of
the affected trees are LCSD Champion Trees or Registered Old and Valuable
Trees. All the affected trees are common species with an average of medium to
low amenity value. Although, some of
the affected trees would be transplanted, there are still some slight to
moderate residual impacts on existing trees during construction phase. Tree planting would be provided
in the area affected by the Project, where practicable. It is considered that
the residual impact on existing trees would be reduced to insubstantial level
with the implementation of compensatory mitigation measures after 10
years. Detailed tree felling
application and compensatory planting proposals would be submitted to seek
approval from relevant authorities in accordance with ETWBTC 3/2006 prior to
construction of the Project. Residual impacts on some of the
LCAs and VSRs are envisaged during construction phase but the impacts are
temporary in nature and could be reduced with appropriate mitigation
measures. Mitigation measures, such as landscape planting, green roof on facilities buildings, green landscape podium on WKT, and natural drainage
channel at SSS, would be implemented to alleviate the visual impacts during
the operation phase. |
|
Cultural Heritage |
Direct impact on Archaeological
Sites, declared monument and graded buildings has been avoided during the
design stage of Project. Based on
findings of terrestrial archaeological investigation, mitigation measures
including a further archaeological investigation, a rescue excavation for
archaeological remains, watching brief in Tse Uk Tsuen works area (TUW),
restriction of works area extension (TPP), and regular site audit (LKST) are
recommended to minimise the potential impact on archaeological resources. Marine archaeological investigation at LKST dredging area also
confirmed that there would be no impact on marine archaeological remains. There
would be direct impact on the local earth shrines. As agreed with local villagers, the
affected earth shrines at Nam Hing Lei, Leung Uk Tsuen and Tai Kong Po Tsuen
would be relocated by themselves before commencement of construction works. Control of vibration levels from the proposed blasting and
excavation activities within a peak particle velocity (ppv) limit of 25mm/s
is recommended to prevent potential indirect vibration impact to all
identified built heritage resources during construction phase. A field survey at ex-Lai Chi
Kok Hospital (LCKH) reveals that the timber trusses of Block Q of LCKH is in
poor condition and cracks exist on the brick walls of Blocks P and W, which
are located at the Lower Section. To
minimize the potential vibration impact from the tunnel construction at these
particular areas, further condition survey and appropriate consolidation
works will be conducted at Blocks P, Q, W and inaccessible areas if
necessary. Vibration monitoring is
also recommended to be conducted at LCKH to confirm that there would be no
unacceptable deviation from the set limits. In
addition, mitigation measures including condition survey and vibration
monitoring at Cheung Yuen (LET-06) have also been considered and would be
conducted if consent is given by property owner to minimize the potential
vibration impact. The use of sensibly designed screen hoardings for
mitigating landscape and visual impacts would be implemented for reducing the
potential visual impact on identified heritage buildings to acceptable
levels. |
|
Land Contamination |
Based on site appraisals in respect of land
contamination, including a desk-top review on historical/current land uses
and site inspections, along the alignment of the Project and associated works
sites and areas, most of the sites are identified not having adverse
impacts. Along the alignment and the
proposed facilities, site investigations have been conducted at 8 accessible
sites at the current stage. A total of
25 sampling locations have been tested for contamination. Only 3 out of 100 soil samples tested was
found to be contaminated with semi-volatile organic chemical
(bis-(2-Ethylhexyl)phthalate) at Sites H
(KCV) and Site Q (SSS) from
Stage I SI works. The contamination is considered to be localized with only a
small volume of soil (approximately Biopiling/ chemical oxidation is proposed
to treat the SVOC (bis-(2-Ethylhexyl)phthalate) identified. After remediation, the sites would be
complied with the relevant RBRGs. No adverse residual environmental impact in
respect of land contamination is anticipated upon completion of the
recommended remediation actions. There are some sites identified for next
stage of investigation. Based on
initial evaluation, there are no insurmountable impacts. |
|
Waste management implications |
Construction
waste arisings have been identified based on the proposed construction
activities and would comprise C&D materials (including excavated
materials, materials from demolition works and site formation), sediment,
general refuse from workforce, chemical waste from maintenance of construction
plants and equipments and sewage from on-site staff and worker. Provided that the identified waste arisings
are to be handled, transported and disposed of using approved methods and the
recommended good site practices are to be followed, adverse environmental
impacts would not be expected during the construction phase. Methods
to minimise the generation of waste has been investigated which focus on the
construction methods of tunnels, ventilation buildings and stations. To maximise reusable volume, the materials
would require on-site sorting once generated, on-site reuse of 619,900 m3
has been identified for backfilling of the Project. Broken concrete and bitumen with a volume
of 89,600 m3 could be reused on-site as filling materials. Further reuse in other projects for
beneficial use have also been evaluated, these includes, transport of
materials for reclamation of HZMB, quarries and concrete batching plant,
mainly as filling materials or aggregates for concrete batching. Currently, an estimated volume of 3,262,600
m3 of materials may be reused in HZMB while 1,320,000 m3
of granites may be reused as concrete aggregates. Volume of reuse is subject to further
revision by the relevant project proponents, consultants and government. Approval has been given by the Highway
Department and Civil Engineering and Development Department. It is estimated that 5,813,700 m3
of materials would be disposed at Taishan after exploring the possible reuse
outlets in Methods
to minimise the volume of sediment generated have been explored and
implemented. The total volume of dredged/ excavated sediment generated from
the Project is estimated to be approximately 308,200 m3. Based on
the results of the chemical and biological screening, approximate 120,800 m3
sediment is suitable for Type 1 – Open Sea Disposal, 184,800 m3
sediment requires Type 2 – Confined Marine Disposal and 2,600 m3
sediment requires Type 3 – Special Treatment/Disposal. The final disposal
sites for the sediments will be determined by the Marine Fill Committee (MFC)
and a dumping licence will be obtained from EPD prior to the commencement of
the dredging/ excavation works. With
the implementation of the recommended mitigation measures in Section 10 in
accordance with the requirements of PNAP 252, no adverse environment impacts
would be expected. The
types of waste generated during the operation of the Project would be general
refuse from the passengers, staff and any commercial operators at WKT,
ventilation buildings and shafts, industrial waste from the maintenance
activities and chemical waste from operational activities. The handling, collection, transportation
and disposal practices of the identified waste generated should follow the
current practices at other operating railway lines and hence would pose no
impact. |
|
Water quality |
Water quality impacts from land-based construction
activities would be controlled by implementing the recommended
mitigation measures, such as control measures on site runoff and drainage
from the works areas to minimise construction runoff, and particularly
on-site treatment of any contaminated wastewater prior to discharge. Hydrological Impact on groundwater
system has been conducted for the Project. Assessment results indicated that
the proposed tunnelling works would cause no unacceptable impacts to the
groundwater regime with proper implementation of the recommended mitigation
measures. The proposed dredging works at LKST would be small
in scale and undertaken at a slow production rate. Water quality impact
during the proposed dredging works would be controlled by implementation of
mitigation measures such as deployment of double silt curtain as far as
practicable and good site practices. No unacceptable water quality impact
would be expected from the dredging works. During operational phase, track
run-off, tunnel seepage and effluent discharges from terminus, ventilation
buildings and maintenance activities would have no adverse water quality
impact provided that mitigation measures are incorporated in the design. The operational water quality
impact from the proposed seawater cooling system has been quantitatively
assessed. No unacceptable water quality impact from the proposed seawater
cooling system was predicted. Sewerage impact assessment has
been conducted for the Project.
Assessment results indicated that there would be no adverse impacts to
the existing sewerage systems due to the additional sewage / wastewater flow
from this Project. |
|
Air quality |
Potential dust impacts would be
generated from excavation activities, material handlings, wind erosion,
stockpiles, spoil removal, material delivery, barging points and concrete
batching plants during the construction phase. Fugitive dust impacts would be controlled
by implementation of dust suppression measures stipulated in Air Pollution
Control (Construction Dust) Regulation, good site practices and proposed
mitigation measures. The predicted
maximum hourly and 24-hour average TSP levels at the representative ASRs
would comply with the statutory requirement.
The dust impacts on the ASRs are considered insignificant. The operation of Project and diesel locomotives at SSS
would not pose any adverse air quality impacts. With the provision of
mechanical air ventilation system which is designed fulfilling with the EPD
PTI guideline, no adverse air quality impact would be expected. |
|
Hazard to Life |
A QRA has been carried
out to assess the hazard to life issues arising from the storage and
transport of explosives during construction of the Project. The criterion of the
EIAO-TM for Individual Risk is met. The assessment results show that the
societal risk lies within the 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. This complies with the EIAO-TM and EIA
Study Brief requirements. The location of all relevant
Potentially Hazardous Installations (PHIs) have been reviewed with regards to
the Project alignment, explosives magazines and other works areas for both
the construction phase and the operation phase of the project. No PHI
requires assessment under the conditions of the EIA Study Brief. |
|
Landfill Gas Hazard |
A qualitative
assessment of the potential hazards associated with landfill gas migration from
NTML to the tunnels during the construction and operation phases; and GDBL to
the Barging Point and SLSL to the Nursery Site during the construction phase
has been undertaken. The potential
landfill gas hazards associated with the Project are evaluated using the
source-pathway-target model in accordance with the EPD’s Guidance Note on
Landfill Gas Hazard Assessment. The
NTML, GDBL and SLSL have been restored under the North-east New Territories
Landfills and Gin Drinkers Bay Landfill Restoration Contractor and being
managed by the restoration contractor.
All three landfills are considered as a “medium” source of gas
migration. The source-pathway-target
analysis shows that landfill gas risk posed by NTML to the tunnels will be
medium while the landfill gas risk posed by the GDBL and SLSL to the Barging
Point and the Nursery Site during the construction phase, respectively, will
be very low. Landfill gas protection
measures and monitoring requirements have been recommended for the
construction and operation of the Project.
It is expected that with the proposed protection measures in place,
the potential risk of landfill gas migration to the Project will be minimal. |
|
Impacts on the Restored Ngau Tam Mei
Landfill |
An assessment was
performed to identify the potential impacts during both construction and
operation of the Project on the restored NTML (or Landfill), particularly
slope stability, settlement, and groundwater/leachate levels and flow; and
conversely to determine the potential impacts of the NTML on the tunnels,
specifically the groundwater/leachate quality. The existing restored
NTML slopes are stable (with a minimum Factor of Safety of 1.8). The calculated minimum Factor of Safety
will be reduced slightly to 1.6 under the imposed conditions of
conservatively large vibrations assuming both tunnels will be constructed in
rock at the same time. As the
calculated minimum factor of safety is still well above the minimum value of
1.2 required by the Restoration Contract, no mitigation measures are
necessary. Long-term settlement of
waste placed in landfills results from the naturally-occurring process of
decomposition and gas generation. The
surface of the NTML is expected to settle up to 750mm over the course of the
modelled duration. Based on commonly
employed modelling methods and under conservative assumptions, it is
anticipated that the construction of the tunnels in rock beneath the Lower
Platform of the Landfill will not cause more than 30mm of additional
settlement. Given the location of the
tunnels beneath the Landfill, the constructed gradients across the Landfill
surface and the anticipated settlement pattern; it is anticipated that the
construction of the tunnels will not cause adverse impacts on the restored
NTML (such as reversal of the ground surface gradients; rupture of the
geomembrane component of the capping system, damage to the leachate and
landfill gas management systems, additional damage to the surface water
management features or damage to the road) and therefore no mitigation
measures will be required. The Project tunnels in
the vicinity of the Landfill are to be formed using closed-face TBM’s and
constructed with reinforced concrete sealed at the joints. As a result, there will be no flow of
groundwater or leachate into the tunnel bore, and therefore no changes
anticipated in the hydrogeologic regime; specifically the groundwater and
leachate levels or flow. Groundwater
passing through the disposed waste mass has resulted in relatively minor
concentrations of contaminants detected in down-gradient wells. Recent groundwater quality testing result
performed at the tunnel alignment and the level of the tunnels suggested that
groundwater will not has adverse impact on the concrete tunnel. |