1.1
In April 2008, the MTR Corporation
Limited (MTRC) was requested by Hong Kong Special Administration Region (HKSAR)
to proceed with further planning of the proposed Hong Kong
section of the Guangzhou-Shenzhen-Hong
Kong Express Rail Link (XRL).
1.2
The Hong Kong
Section of the XRL (hereinafter referred to “the Project”) is a 26 km long underground railway running from West Kowloon to boundary at Huanggang, as shown in Figure Nos. NOL/ERL/300/C/XRL/ENS/M50/001 to 003. The two termini of the XRL will be at West Kowloon in
Hong Kong and Shibi in Guangzhou. Boundary crossing facilities will be provided
in the West Kowloon Terminus (WKT).
1.3
This Executive Summary highlights the key
findings of the Environmental Impact Assessment (EIA) for the Project to comply
with the EIA Ordinance (EIAO).
Scope and Nature of the Project
2.1
The Project comprises the following key elements:
·
Approximately
26km of underground railway running from the terminus in West
Kowloon to the boundary at Huanggang;
·
A
terminus in West Kowloon, and its associated building
elements such as ventilation facilities, public
transport interchange, traction sub-station, and seawater cooling facility;
·
Seven
tunnel ventilation buildings at Mai Po,
Ngau Tam Mei, Pat Heung, Shing Mun, Kwai
Chung, Nam
Cheong and Mong Kok West; and an Emergency Access Point (EAP) at Tai Kong Po;
·
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.
2.2
Apart from the key elements above,
supporting works areas, access roads, barging facilities, site explosive
magazine and nursery sites will be required to support the construction of the
Project.
2.3
The Project is a designated project (DP) under the EIAO with
the following DP elements:
·
A railway and its associated station (Item A.2 of
Part I of Schedule 2 of the EIAO);
·
A railway siding and maintenance workshop (Item A.4
of Part I of Schedule 2 of the EIAO);
·
A railway tunnel more than 800m in length between portals
(Item A.7 of Part 1 of Schedule 2 of the EIAO); and
·
Project includes works partly or wholly in a
country park or special area, a conservation area, and a site of special
scientific interest (Item Q.1 of Part 1 of Schedule 2 of the EIAO).
Purpose and Benefit of the Project
2.4
The XRL will form part of the national high-speed railway
network, connecting Hong Kong with Guangzhou,
with intermediate stations at Futian, Longhua and Humen, outside of Hong Kong. The
XRL will provide a fast and convenient railway service linking the cities, with
the journey time between Hong Kong and Guangzhou
reduced from about 100 minutes as at present to about 50 minutes.
2.5
With the XRL Mainland section connected to the Beijing-Guangzhou
Passenger Line and the Hangzhou-Fuzhou-Shenzhen Passenger Line, Hong Kong can
be connected directly with major Mainland cities, such as Beijing
and Shanghai,
as well as other major cities in the Pearl River Delta via the Intercity Rapid
Rail.
2.6
The XRL will help to promote Hong Kong as the gateway to the
Pearl River Delta area, further strengthen the economic ties and cooperation
between Hong Kong and the Mainland, promote
mutual economic prosperity and development, and raise the competitiveness of
the region as a whole. The Project
will not only allow Hong Kong to have better
social and economic integration with cities in the Pearl River Delta and other
major cities in the Mainland, but will also facilitate and promote business and
tourism.
2.7
In addition, transportation by rail is considered to be more
environmentally friendly in terms of energy conservation and pollution
reduction. During the operation of
the Project, the public will be encouraged to use this environmentally friendly
public transport which will reduce problems related to air and noise pollution
as well as other associated deleterious effects generated by automobile usage.
Selection of the Project Scheme
2.8
In the alternative alignment schemes and
construction options selection process, significant environmental resources,
e.g. Mai Po Inner Deep Bay Ramsar Site, Country Parks, Declared Monument
and graded historical buildings were avoided, and other factors such as
geographical and geological consideration, land resumption, site constraints,
constructability, operation flexibility and maintainability and disruption to
the community were also considered.
2.9
The selected Project alignment scheme is a feasible design solution
offering clear benefits in terms of operations, environment, construction and
land related issues.
Major Facilities of the Project
2.10
The West Kowloon Terminus (WKT)
will be located in immediately north of the proposed West Kowloon Cultural District
(WKCD) between Kowloon Station of Airport Express Line (AEL) on the west and
Austin Station of Kowloon Southern Link (KSL) on the east. The WKT will not only form an integrated
railway/transport/development hub in West Kowloon,
providing point-to-point connection via the existing MTR network, but could
also enhance the WKCD as a regional cultural hub. WKT will be
developed as a gateway to the Mainland, with distinctive architectural and
landmark features.
2.11
A total of seven tunnel
ventilation buildings will be provided, five in the New
Territories and two in the western
side of Kowloon. A ventilation building will also
be provided to the north of WKT to serve for both terminus and track fan
ventilation. In addition to the air exchange route for
the railway system, ventilation buildings will be an essential component for
the tunnel smoke control system and will serve as an access point for rescue
operation as well as a fire escape from the tunnel in an emergency situation,
such as train fire.
2.12
Stabling sidings is required to
fulfill the operational and maintenance requirements, by providing stabling
facilities, serving as a small scale engineering
depot with engineering trains for necessary maintenance facilities (e.g.
maintenance of permanent-way, overhead line, signalling and control, etc), as
well as handling of emergency situation such as derailment or emergency
servicing.
2.13
The ERS
is required for fire fighting and should be located approximately at the
mid-point of the tunnel alignment. The ERS is designated as a place for trains
to stop and to discharge passengers either to another train in the event of
mechanical problems or evacuation to ground level in the event of a train fire. The ERS will be a depressed box with an
open top for safety reason.
Firemen’s lifts and staircases will be provided to allow ease of access
for the rescue team.
Construction
Activities
2.14
As the Project is
an underground railway, major construction works are tunnelling works and
cut-and-cover works at shafts, ERS and WKT. Drill
and blast construction method will be adopted for rock tunnels while bored
tunnelling method will be adopted for mixed and soft ground tunnels. Cut-and-cover construction method will
be adopted for few tunnel sections which require this conventional method.
2.15
Marine works have been avoided except minor dredging works required
for the construction of the barging facility in Lung Kwu Sheung Tan.
Preliminary
Construction Programme
2.16
The proposed
construction is scheduled to commence in late 2009, for completion in 2015.
Public Consultation
2.17
MTRC considers that the
views and the support of the community are important in the planning and design
of the Project. Extensive public
consultation has been conducted since the planning stage of the Project,
including meetings with District Councils (DCs), Rural Committees (RCs), local
residents along the Project alignment and a series of roving exhibitions. A total of 33 and 29
meetings/consultations were conducted with DCs/RCs and local residents
respectively. The public generally
supports the development of the Project and their views have been considered in
the planning and design process.
2.18
For the EIA Study,
continuous dialogue with Non-Government Organizations (NGOs) has been
conducted.
3.1
The EIA Study was conducted in accordance with the EIAO
Study Brief No. ESB-197/2008, following the guidelines on assessment
methodologies in the Technical Memorandum on Environmental Impact Assessment
(EIAO-TM). The main findings of the
EIA study are summarized below.
Ecological
Terrestrial Ecology
3.3
A literature review and ecological field surveys have been
conducted. Potential impacts on
significant ecological resources, such as Wetland Conservation Area and Country Park, have been avoided in the alignment
scheme and construction method selection process. Through underground tunneling
construction methods, above-ground works are minimized and only several areas
in the northern section of the Project have more natural habitats.
3.4
In these works areas, the identified habitats are generally
of low ecological value, and flora and fauna recorded are predominantly common
species in Hong Kong. There would be approximately 53 ha of low
value habitats lost, 60% of which are developed area / wasteground, and the
direct ecological impact from the Project is considered to be low.
3.5
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.
3.6
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 and shaft construction works to prevent/minimise groundwater leakage
into the tunnel/works areas and any significant groundwater drawdown. A program will be implemented to monitor
groundwater levels.
3.7
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.
Marine Ecology
Lung Kwu Sheung Tan
3.8
Marine works would be conducted to form a berthing area for upgrading 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 0.65
ha).
3.9
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.
West Kowloon
3.10
The impact on 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
Pond Fisheries
3.11
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 Mai Po
and Ngau Tam Mei, such as construction dust and site runoff, would be
negligible with implementation of good site practices.
Marine Fisheries
3.12
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 West Kowloon.
The only potential impacts would be minor and localized, temporary loss
of low value marine area within the LKST dredging area.
Airborne Noise
Construction Phase
3.13
The potential source of noise
arising from the construction phase of the Project would mainly be the use of powered
mechanical equipment (PME) for the construction activities. In the absence of
any control measures, construction noise levels exceeding the noise criteria of
EIAO-TM would be expected at a number of noise sensitive receivers (NSRs) due
to their proximity to the works areas.
3.14
To alleviate the construction
noise impacts, considerations including minimization of construction plants,
works in phases and avoidance of simultaneous operation of PME, have been taken
into account as far as practicable to develop a feasible construction plant
inventory and programme. Further
mitigation measures such as quieter plant, silencer, movable noise barrier,
noise insulating fabric and acoustic enclosure have been recommended, taking
account of site constraints, to achieve the EIAO-TM daytime construction noise
criteria, and no adverse residual impacts are anticipated.
3.15
Potential cumulative noise impacts
with concurrent major works in the assessment area were considered and
significant impacts were not expected.
Operation Phase
3.16
During the operation phase, trains
passing through the ERS at high speed, as well as the reverberant noise built
up inside the ERS, would be the main source of airborne noise impact. Other
airborne noise sources in Shek Kong would be train movements and trains idling
in the maintenance shed within the SSS, and fixed plant provision at the
SSS.
3.17
The worst case scenario of train
frequency based on the maximum line operational capacity of XRL has been
developed for the assessment. Operational
airborne railway noise assessment has been conducted and noise exceedances at
the NSRs located close to the SSS and ERS are predicted, if unmitigated. Therefore, noise control measures,
including a 8m high noise barrier next to ERS and absorptive panels inside the
ERS, have been recommended to comply with the EIAO noise criteria.
3.18
A 5.5m high barrier is also
recommended to be erected next to the maintenance train’s shed for mitigating
the potential impact from the operation of the SSS. Fixed plant noise such as from air
compressor and chillers in SSS, tunnel ventilation and WKT would be controlled
by appropriate treatment to allowable maximum sound power levels, for complying
with EIAO noise criteria at NSRs.
3.19
The relevant guidelines of the Hong
Kong Planning Standards and Guidelines have been adopted as far as practicable
to alleviate the potential noise impact from the proposed public transport
interchange (PTI) in West Kowloon. The potential impact is expected to be
minimized, with the provision of landscape deck and by locating the ingress and
egress points away from sensitive receivers.
Ground-borne Noise
Construction Phase
3.20
Potential construction
ground-borne noise would arise from the use of tunnel boring machine (TBM) and PME
for construction of tunnel and adits.
Ground-borne construction noise assessment based on worst case scenario
indicates that the noise impacts on neighbouring noise sensitive receivers
would comply with the EIAO noise criteria.
There may be, however, small exceedance of the criteria at several
representative sensitive receivers in West Kowloon and Shek Kong due to the TBM
operation for a short period of about two or three days, based on the TBM
operation data from the Sheung Shui to Lok Ma Chau Spur Line Project. Monitoring of TBM operation is
recommended to monitor and confirm the ground-borne noise levels. Scheduling of works and close liaison
with the affected receivers would be conducted during the TBM operation to
minimize any potential disturbance.
Operation Phase
3.21
Operation phase ground-borne noise
levels have been predicted based on the maximum operation capacity of railway
system and the use of standard resilient baseplates. Assessment results indicate that the predicted
ground-borne noise levels at the sensitive receivers would comply with the
stipulated noise criteria.
Therefore no mitigation measures would be required along the alignment
during the operation phase, but low noise mitigation trackform has been proposed
to further minimize the noise levels.
Provision proposal for installation of low noise trackform will be
reviewed based on the updated ground-borne noise levels.
3.22
With the predicted low
ground-borne noise levels at the sensitive receivers, it is anticipated that
there would be no cumulative effect from other rail lines, including Kowloon
Southern Link, Tung Chung Line, Airport Express Line and Tsuen Wan Line.
Landscape and Visual
3.23
The XRL will be largely constructed underground, and
therefore potential landscape and visual impacts have been minimized and
confined to above-ground works.
3.24
The
key sources of impacts during operation phase are confined to above-ground
structures including SSS, WKT and ventilation buildings/EAPs at Mai Po, Ngau Tam
Mei, Tai Kong Po, Shek Kong, Pat Heung, Shing Mun, Kwai
Chung, Nam
Cheong, Mong Kok West and West Kowloon. Considerations of potential visual
impacts were taken into account in the development of the aesthetic
architectural design of these structures.
3.25
The key sources of impact during
construction stage are from activities associated with the construction of the
above-ground structures within the works areas of the Project.
The surface works would inevitably affect existing landscape resources such
as trees. Potential impacts have been
considered during the preliminary design of the Project to minimize works areas
and avoid direct impacts on significant landscape resources.
No Champion Trees nor Registered Old and Valuable Trees will
be affected by the Project. All the
affected trees are common species with an average of medium to low amenity
value. A total of approximately
5,200 trees would be retained on-site, approximately 1,100 trees would be
transplanted, and around 5,500 trees would be felled. Detailed tree felling application and
compensatory planting proposals will be prepared and submitted to seek approval
from relevant authorities in accordance with ETWBTC 3/2006 requirements, prior
to construction of the Project.
3.26
It is considered that the
landscape and visual impacts associated with the construction and operation of
the Project are considered to be acceptable with the implementation of the
appropriate mitigation measures, such as landscape planting, green roof on
facilities buildings, green landscape podium on WKT, and natural drainage
channel at SSS. The
visual impact of the ventilation shafts at a prominent location within WKCD
would be dependent on the final design and the manner in which it may be
integrated with the future buildings in WKCD, and therefore the significance of
visual impact cannot be determined at this stage. The scale, location,
disposition, design and integration strategies of the ventilation shafts would
however be further refined in the detailed design stage such that their visual
impacts would be minimal.
Cultural Heritage
Terrestrial Archaeology
3.27
Direct impact on known
archaeological sites has been avoided during the selection of the Project
alignment. A desktop review and field
walks were conducted to identify areas with archaeological potential. The findings indicate that the works
areas in Tai Kong Po, Shek Kong and Pat Heung may have archaeological
potential, and an archaeological investigation was therefore conducted at these
works areas.
3.28
Some archaeological artefacts were
discovered at the southern portion of the SSS, therefore a rescue excavation is
recommended to be conducted prior to commencement of construction works at this
area to preserve any artefacts
by detailed records.
3.29
There are inaccessible sites in
the works areas that may also have archaeological potential, but currently
being occupied and disturbed by different land uses, such as pig and chicken
farms, open storage and garages. To
investigate whether there is any archaeological remains in these inaccessible
areas, a further archaeological investigation is recommended to be conducted
upon the completion of land resumption and prior to the construction works at
these areas, identifying mitigation measures as necessary, in liaison with the
Antiquities and Monuments Office.
Other mitigations such as watching brief, site audit and restriction of
works area would also be adopted to minimize the potential impact on
terrestrial archaeology.
Marine Archaeology
3.30
A desktop review was conducted to
investigate any marine archaeological potential in the proposed dredging area
in LKST. There has been extensive
reclamation on the area adjacent to the LKST barging point. These disturbances caused by the
previous marine works would have potentially damaged submerged archaeological
resources, if any. No impact on the
affected seabed with low archaeological potential is anticipated. A marine archaeological investigation
was conducted and the findings have confirmed that there are no archeological
remains in the proposed dredging area.
Built Heritage
3.31
A desktop literature review and
field surveys were undertaken to establish built heritage baseline
condition. Significant
resources including Declared
Monuments and graded
buildings such as Yi Tai Study Hall and Lai Ancestral Hall have been avoided
during the selection of the Project alignment. The only direct impact is that local
earth shrines at Nam Hing Lei, Leung Uk Tsuen and Tai Kong Po Tsuen would be
affected. Following liaison with
the local villagers, the affected shrines would be relocated by the villagers
in Shek Kong and Tai Kong Po.
3.32
There may be potential indirect vibration
impact on the heritage resources induced by blasting. Mitigation measures such as control of
vibration levels by adjusting appropriate quantity of explosives and vibration
monitoring at Ex-Lai
Chi Kok
Hospital are
recommended. With these measures in
place, it is anticipated that the Project would have no adverse impacts on
cultural heritage resources during construction phase.
3.33
With the rail alignment located in
deep underground tunnel and incorporation of aesthetic design for the
above-ground structures, significant indirect vibration and visual impacts to
built heritage during the operation phase are not envisaged.
Land Contamination
3.34
The land contamination assessment
has examined the potential contaminative landuses within the works areas and
their potential impacts to future use.
A desktop study and site inspections were conducted to identify works
areas with potential land contamination issues, such as vehicles repair workshop,
scrap yard and former oil depot. A
Contamination Assessment Plan (CAP) was prepared, based on which site
investigation (SI) works were undertaken in these areas.
3.35
Based on the SI results, a
Contamination Assessment Report (CAR) was prepared. Assessment indicates that soil samples
collected at only two sampling sites were found to have
bis-(2-Ethylhexyl)phthalate exceeding the relevant Risk-based Remediation
Goals. A Remediation Action Plan
(RAP) for the localized soil contamination was prepared to identify appropriate
soil remediation methods, handling and disposal of contaminated soil. The volume of contaminated soil required
for remediation is estimated to be small, around 90m3 and will be
treated and reused on-site as far as practicable. All groundwater samples comply with
assessment criteria, and therefore no contamination of groundwater were found.
3.36
Further SI works for inaccessible
sites during the EIA stage will be conducted, upon completion of land
resumption and prior to the commencement of construction works at these sites.
Depending on the schedule of land resumption and the commencement of the
construction works for each works area, revised CAPs, supplementary CARs and/or
RAPs will be prepared and submitted in separate packages to Environmental
Protection Department (EPD) for endorsement.
Waste
Management
3.37
Construction waste of the Project
would include construction and demolition (C&D) materials such as excavated
materials and materials from site formation and demolition works, sediment,
general refuse and chemical waste from maintenance of construction plant and
equipment.
3.38
Methods in minimisation of waste
generation were considered in the preliminary design of terminus, tunnels and
ventilation buildings. These have
reduced the volume of total waste generation of the Project by 1,000,000 m3
down to approximately 9,800,000 m3.
3.39
Opportunities to re-use materials
have also been fully considered. An
estimated 619,900 m3 of material would be reused as backfilling
materials at Mai Po, Tai Kong Po, Nam Cheong and West
Kowloon while 89,600 m3 of materials generated from
demolition works could be reused on-site.
3.40
A surplus 9,100,000 m3
of materials would be transported off-site for beneficial use in other possible
outlets, such as the man-made island of the Hong Kong-Zhuhai-Macao Bridge,
concrete batching plant and Public Fill Reception Facilities in Hong Kong, and
Tai Shan in China.
3.41
The total volume of
dredged/excavated sediment generated from the Project is estimated to be about
238,500 m3.
Approximately 99,100 m3 sediment would be suitable for Type 1
– Open Sea Disposal, 136,800 m3 sediment requires Type 2 – Confined
Marine Disposal, and 2,600 m3 sediment for Type 3 – Special
Treatment/Disposal, in accordance with Practice Note for Authorized Persons and
Registered Structural Engineers PNAP 252 (PNAP 252). The materials will be disposed of to the
designated mud pits in Hong Kong following the
PNAP 252 in consultation with the Marine Fill Committee and EPD.
3.42
The main types of waste generated
during the operation of the Project would be general refuse from passengers,
staff and commercial operators at the WKT/SSS; industrial waste from
maintenance activities and chemical waste from operational activities. The handling, collection, transportation
and disposal practices of the identified waste generated will follow the
current practices at other operating railway lines.
Water Quality
Construction Phase
3.43
During the construction phase,
water quality impacts from land-based construction activities would be related to
potential release of sediment-laden run-off from surface works areas, open cut
excavation and tunnelling works.
Impact on water quality would be insignificant, with the implementation
of control measures and good site practice, such as sediment trap, provision of
cover for stockpiles to minimize site runoff, and proper site drainage.
3.44
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.
3.45
The water quality impact during
the proposed dredging works for the LKST Barging Point has been quantitatively
assessed. The impact generated from
the dredging works would be localized and minor, thus would unlikely contribute
any significant cumulative water quality impact. To minimize the water quality impact,
mitigation measures such as silt curtain and closed grab dredger have been
adopted.
Operation Phase
3.46
The main operational impacts from
the Project would come from tunnel seepage and effluent discharges from the
terminus, ventilation buildings and maintenance activities. These could be minimized through control
measures such as provision of silt trap and proper sewerage system. The water
quality impact from the proposed seawater cooling system on the harbour water
was modeled and predicted to be localized and minor, in compliance with the
Water Quality Objectives.
3.47
A sewerage impact assessment has
been conducted for the Project.
Assessment results indicate that sewerage facilities will be provided in
accordance with regulatory requirements and there would be no adverse impacts
to the existing sewerage systems.
Air Quality
Construction Phase
3.48
Potential air quality impacts from
the construction works for the Project would be mainly related to construction
dust from excavation, materials handling, spoil removal and wind erosion, as
well as operation of concrete batching plant, temporary stockpiles and barging
facilities.
3.49
Mitigation measures specified in
the Air Pollution Control (Construction Dust) Regulation and specific dust
control measures for the concrete batching plant and barging facilities have
been recommended, e.g. regular watering, covering dusty material storage area,
provision of dust collectors. With
the implementation of the dust suppression measures, the dust levels at Air Sensitive
Receivers (ASRs) would comply with the dust regulatory criteria.
Operation Phase
3.50
As XRL trains are electrically
powered, there would not be any emissions of air pollutants generated from the
trains and exhausted through ventilation buildings to outside nearby ASRs. As such, no air quality impact is
envisaged.
3.51
The mechanical air ventilation
system for the proposed PTI in West Kowloon
has been designed in accordance with EPD Practice Note for Professional Persons
– Control of Air Pollution in Semi-Confined Public Transport Interchange
(ProPECC PN1/98), and air quality impact during its operation is therefore not
anticipated.
Hazard to Life
3.52
The storage and transport of explosives for the Project construction
have been assessed in a Quantitative Risk Assessment. The criterion of the EIAO-TM for
Individual Risk is met. The assessment results show that the societal risk lies
within the As Low As Reasonably Practicable (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. The results show compliance with the
ALARP principles and Risk Guidelines (EIAO-TM Annex 4) provided recommendations
are implemented.
Landfill Gas
Hazard
3.53
A
section of the XRL alignment will be located underneath the Ngau Tam Mei Landfill
(NTML), and the Barging Point in Kwai Chung and the Nursery Site in Siu Lang
Shui will be located within the Consultation Zones of the Gin Drinkers Bay
Landfill (GDBL) and Siu Lang Shui Landfill (SLSL), respectively. In accordance with the requirements of Annex 7 of the EIAO-TM, a qualitative assessment of the
potential hazards associated with landfill gas migration from NTML to the XRL
tunnels, GDBL to the Barging Point and SLSL to the Nursery Site has been
conducted.
3.54
All three restored 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 XRL tunnels during both
construction and operation phases is 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.
3.55
Landfill Gas protection measures
and monitoring requirements have been recommended for 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.
Impact on the
Restored Ngau Tam Mei Landfill
3.56
An assessment was performed to identify
the potential impacts due to the construction and operation of the proposed XRL
on the restored NTML, particularly slope stability, settlement, and
groundwater/leachate levels and flow; and conversely to determine the potential
impacts of the NTML on the proposed XRL tunnels, specifically the
groundwater/leachate quality.
3.57
The assessment concluded that the
construction and operation of the XRL will not have adverse impact on the
restored NTML. Analysis of the
groundwater quality suggested that groundwater will not have adverse impact on
the tunnel concrete. Hence, no measures will be required to
mitigate the potential impact of the XRL tunnel on the NTML and vice versa.
4.1
An environmental monitoring and audit
(EM&A) programme will be implemented during the construction and operation
of the Project, to check effectiveness of the recommended mitigation measures
and compliance with relevant statutory criteria.
5.1 This EIA
study has identified and assessed potential environmental impacts of the
Project, in accordance with the EIA study brief and EIAO-TM guidelines. Overall,
the EIA study has concluded that the Project would be environmentally
acceptable, in compliance with environmental legislation and standards. With the implementation of environmental
control measures during construction and operation phases, there would be no
adverse residual impacts from the Project.
This will be checked by a comprehensive environmental monitoring and
audit programme.
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