Contents
1.1 Background Information
1.2 Policy
1.3 EM&A Programme Objectives
1.4 Scope of the EM&A Programme
1.5 Project Organization
1.6 Terminology
2.1 Scope of the Project
2.2 Northern Section in Tuen Mun
2.3 Submarine Tunnel
2.4 Southern Section at HKBCF/
North Lantau
2.5 Works Area
2.6 Sewage & Drainage
2.7 Project Programme
2.8 Concurrent Projects
2.9 Traffic Data and Assumptions
3.1 Air Quality Parameters
3.2 Monitoring Equipment
3.3 Laboratory Measurement / Analysis
3.4 Monitoring Locations
3.5 Baseline Monitoring
3.6 Impact Monitoring
3.7 Event and Action Plan for Air Quality
3.8 Dust Mitigation Measures
4 Noise
4.1 Introduction
4.2 Noise Mitigation Measures
5.1 Introduction
5.2 Mitigation Measures
5.3 Water Quality Parameters
5.4 Monitoring Equipment
5.5 Laboratory Measurement /
Analysis
5.6 Monitoring Locations
5.7 Baseline Monitoring for Water
Quality
5.8 Efficiency of Silt Curtain
5.9 Impact Monitoring for Water
Quality
5.10 Post-construction Monitoring
5.11 Operational Phase Monitoring
5.12 Event and Action Plan
6 Ecology
6.1 Introduction
6.2 Ecology EM&A Procedures
6.3 Design Phase Audit
6.4 Baseline Monitoring
6.5 Construction and Operational
Phase EM&A
6.6 Mitigation and Enhancement
Measures
7 Landscape and
Visual Assessment
7.1 Introduction
7.2 Relevant Legislation
7.3 Methodology and Criteria
7.4 Baseline Monitoring
7.5 Event and Action Plan
7.6 Mitigation Measures
8 Waste Management and Contaminated Land
8.1 Waste Issues
8.2 Contaminated Land
8.3 Waste EM&A Requirements
9.1 Introduction
10 Landfill Gas
Hazard Assessment
10.1 Introduction
11.1 Site Inspections
11.2 Compliance with Legal and
Contractual Requirements
11.3 Environmental Complaints
11.4 Choice of Construction Method
12 Reporting
12.1 General
12.2 Documentation
12.3 Design Audit Report
12.4 Baseline Monitoring Reports
12.5 EM&A Reports
12.6 First EM&A Report
12.7 Subsequent EM&A Reports
12.8 Quarterly EM&A Summary
Reports
12.9 Annual / Final EM&A
Review Reports
12.10 Data Keeping
12.11 Interim Notifications of
Environmental Quality Limit Exceedances
1.1.1.1 According to the findings of the Northwest New
Territories (NWNT) Traffic and Infrastructure Review conducted by the Transport
Department, Tuen Mun Road, Ting Kau Bridge, Lantau Link and North Lantau
Highway (NLH) will be operating beyond capacity after 2016 due to the increase
in cross boundary traffic, developments in the NWNT, and possible developments
in North Lantau, including the Airport developments, the Lantau Logistics Park
(LLP) and the
1.1.1.2 The proposed TM-CLKL if combined with the TMWB will
provide a direct route
linking NWNT and North Lantau, from north to south, the Kong Sham Western Highway (KSWH), port
back-up areas in NWNT, Tuen
Mun River
Trade Terminal, the existing EcoPark in Tuen Mun Area 38, the Airport, the proposed
LLP,
HZMB
and
North Lantau
developments. The
new
connection will
significantly reduce the travelling time between the KSWH and the NWNT region at its northern side, and
1.1.1.3 In 2005, Highways Department
(HyD) commissioned
an engineering
feasibility study (FS), namely Tuen Mun Chek Lap
Kok Link and Tuen Mun Western Bypass – Feasibility Study (Agreement No. CE
28/2005 (HY)), to evaluate the technical
feasibility and
impacts of the Project. The FS recommended
that the
TM-CLKL should be a dual 2-lane road with a total length of about 9 km with about 4 km long submarine tunnel
and 5 km long elevated structure.
1.1.1.4 In order to progress this project, Maunsell Consultants Asia Ltd.
were appointed by HyD to carry out the Assignment on Tuen Mun – Chek Lap Kok Link –
Investigation under Agreement No. CE 52/2007 (HY). The
Assignment
commenced on 19 May 2008 and shall be completed within 24 months, i.e. by
mid-May 2010.
1.1.1.5 The Feasibility
Study initially proposed
an alignment
of the TM-CLKL
comprising a toll plaza island at Tai Mo To and this alignment formed the basis of
the EIA Study Brief (ESB 175/2007). However, subsequent to these documents being prepared and based upon
the proposed
schemes for the
1.1.1.6 The project is a designated project under Section A.1 of Schedule 2 of
the
Environmental Impact Assessment Ordinance (EIAO). As such, the statutory procedures under the EIAO need to be followed and an environmental permit (EP) will be required prior to the commencement of construction.
Thus, as part of this
assignment, an Environmental Impact Assessment (EIA) has been undertaken.
1.1.1.7 The EIA for
the
project has recommended
comprehensive
Environmental Monitoring and Audit
requirements to be undertaken
during the design,
construction and operational stages of
the project. This Report constitutes
the
Environmental
Monitoring
and Audit (EM&A)
Manual for the proposed Tuen Mun - Chek Lap Kok Link (TM-CLKL) Project, providing details of the EM&A recommendations.
1.1.1.8 The
1.2.1.1
The Supervising Officer’s Representative (SOR) and the Contractor
shall adopt
Environmental
Policy Statements in accordance with the requirements of this Manual in order to
foster
a sound EM&A programme to protect the
environment.
The following
policy statements shall be adopted:
·
establish a commitment
to environmental excellence
in all activities
arising from the development project; ·
encourage the adoption
of environmental management
principles
to prevent potential impacts and minimise adverse impacts; and ·
commit to the recommendations in the EIA
study report and related EIA process requirements. |
1.3.1.1 The broad objective of this EM&A Manual is to define the procedures of the EM&A programme for monitoring the environmental
performance
of the TM-
CLKL project during design, construction and implementation.
1.3.1.2 The manual provides details of the environmental monitoring requirements arising
from the EIA including air, noise and water quality, as well
as audit recommendations for the noise, air, water quality, ecology, landscape and visual, waste and cultural heritage.
The purposes of the defined EM&A programme are as follows:
·
to ensure the specified
mitigation
recommendations
of the EIA are included in the design of the project; |
·
to clarify and identify sources of pollution, impact and nuisance
arising from the works; |
·
to
confirm compliance
with legal, contract specifications and EIA study
recommendations; |
·
to provide an early warning system for impact prevention; |
·
to provide a database of environmental
parameters against which to
determine any short term or long term environmental impacts; |
·
to
propose timely, cost-effective and viable
solutions to actual or potential environmental issues; |
·
to monitor
performance
of
the mitigation
measures
and
to assess
their
effectiveness and, whenever necessary, identify any further need for additional measures; |
·
to verify the EIA predicted impacts; |
·
to collate information and evidence for use in public, District Council and Government consultation; and |
·
to audit environmental performance. |
1.3.1.3 EM&A procedures
are required during the design, construction
and
operational
phases of the project implementation and a summary of the requirements for each of
the environmental parameters is detailed in Table 1.1 below.
Table 1.1 Summary
of EM&A Requirements
Parameter |
EM&A Phase |
||
Design |
Construction
Phase |
Operational Phase |
|
Air Quality |
|
Y |
|
Noise |
Not relevant to
the Northern Connection Sub-sea Tunnel Section since there is no noise
sensitive receiver identified for the Project area at Tuen Mun. |
||
Ecology |
Y |
Y |
Y |
Water Quality |
|
Y |
Y |
Landscape and Visual |
Y |
Y |
Y |
Waste/ Contaminated Land |
|
Y |
|
Cultural Heritage |
Not relevant to the Northern Connection Sub-sea Tunnel
Section since cultural heritage resource is not identified for the works area
of the Contract which is marine waters in nature. |
1.4.1.1
The scope of the
EM&A programme is to undertake the following, which follows the demarcation
of monitoring responsibilities set out in Environmental Project Office’s letter
dated 29.10.2013:
a)
Implement monitoring and audit activities
for each environmental parameter as follows: |
|
|||||
Dust: |
i)
Establish baseline
dust levels at specified locations and review these levels on a regular
basis. |
|
||||
|
ii)
Implement
construction dust impact monitoring programme. |
|
||||
Noise: |
i)
Establish
baseline noise, levels at specified locations and review these levels on a
regular basis (Not relevant to the Northern Connection Sub-sea Tunnel
Section). |
|
||||
|
ii)
Implement
construction noise impact monitoring (Not relevant to
the Northern Connection Sub-sea Tunnel Section). |
|
||||
Ecology: |
i)
Implement design
phase audit for ecological dolphin protection specifications, ecological
translocation specifications and design integrated ecological mitigation
measures. |
|
||||
|
ii)
Implement baseline
survey to establish existing ecological conditions. |
|
||||
|
iii)
Implement
construction phase monitoring and audit requirements for ecology resources. |
|
||||
|
iv)
Implement operational
phase monitoring. |
|
||||
Water Quality: |
i)
Establish baseline
water quality levels at specified locations and review these levels on a
regular basis. |
|
||||
|
ii)
Implement
construction water quality impact monitoring programme. |
|
||||
|
iii)
Implement operational
phase water quality impact monitoring programme. |
|
||||
|
iv)
Implement silt
curtain efficiency test. |
|
||||
Landscape and Visual: |
i)
Design
detailed landscape specifications. |
|
||||
|
ii)
Implement baseline survey
to establish/confirm existing landscape and visual conditions. |
|
||||
|
iii)
Implement
construction phase audit requirements for landscape and visual resources. |
|
||||
|
iv)
Implement operational
phase audit requirements for landscape and visual aspects. |
|
||||
Waste: |
i)
Implement
construction phase audit requirements for waste aspects. |
|
||||
Heritage: |
i)
Implement design phase
audit for toll plaza design to ensure set back from grave has been integrated
(Not relevant to the
Northern Connection Sub-sea Tunnel Section). ii)
Implement walkover
survey to confirm existing conditions (Not relevant to the Northern
Connection Sub-sea Tunnel Section). iii)
Implement
construction phase audit requirements for historical resources (Not
relevant to the Northern Connection Sub-sea Tunnel Section). |
|
||||
b)
Liaison and provision of advice to construction site staff on the purposes and implementation of the EM&A programme. |
|
|||||
c)
Identify and resolve environmental issues that may arise from the project. |
|
|||||
d)
Check and quantify the Contractor’s
overall performance, implement Event/Action Plans and recommend and implement remedial actions to
mitigate adverse environmental
effects as identified by
the EM&A programme and EIA. |
|
|||||
e)
Conduct monthly reviews of
monitored impact
data during the construction phase and bi-monthly reviews during the operational phase as
the basis for assessing compliance with defined criteria and ensuring that necessary mitigation
measures
are identified, designed and implemented and to undertake additional ad hoc monitoring and audit as required by
particular circumstances. |
|
|||||
f)
Evaluate and interpret
all environmental
monitoring data
to provide an early indication should any of the environmental
control measures or
practices fail to achieve the acceptable standards and to verify the environmental impacts predicted in the EIA. |
|
|||||
g)
Manage and liaise with
other individuals or parties concerning
any
relevant environmental issues. |
|
|||||
h)
Audit the effectiveness of the Environmental Management System (EMS)
practices and procedures and implement any changes as appropriate. |
|
|||||
i)
Conduct regular site audits of formal or informal nature to assess: |
|
|||||
|
·
the level of the Contractor’s general environmental awareness; |
|
||||
|
·
the Contractor’s implementation of
the recommendations in the EIA; |
|
||||
|
·
the Contractor’s performance as measured by the EM&A; |
|
||||
|
·
the need for specific mitigation measures to be implemented or the
continued
usage of those previously agreed;
and |
|
||||
|
·
to advise the
site
staff of any identified
potential
environmental issues. |
|
||||
j)
Submit EM&A reports which summarise project monitoring and auditing data, with full interpretation, illustrating the acceptability or otherwise
of any environmental impacts
and identification or assessment of
the
implementation status of agreed mitigation measures. |
||||||
1.4.1.2 Thus, this EM&A
Manual provides the following information:
a)
Description of the project. |
|
|
b)
Identification
and recommendations for monitoring requirements for all phases of
development, including: |
|
|
|
-
identification of sensitive receivers; |
|
|
-
monitoring locations; |
|
|
-
monitoring parameters and frequencies; |
|
|
-
monitoring equipment to be used; |
|
|
-
programmes for baseline monitoring and impact monitoring; and |
|
|
-
data management of monitoring results. |
|
c) The organisation management structure, and procedures for auditing of the Project and implementation of mitigation measures that are recommended
for the Project. |
|
|
d)
The environmental quality performance limits for compliance auditing for each of the recommended monitoring
parameters to ensure compliance with relevant environmental quality objectives, statutory or planning
standards. |
|
|
e) Organisation and management structure, and procedures
for reviewing
the design submissions, monitoring results and auditing the compliance of the monitoring data with the environmental quality performance limits,
contractual and regulatory requirements, and environmental
policies and
standards. |
|
|
f) Event and Action plans for impact and compliance procedures. |
|
|
g) Complaints handling, liaison and consultation procedures. |
|
|
h) Interim notification of exceedances,
reporting procedures,
report formats
and reporting frequency
including periodical
quarterly summary reports and annual
reviews to cover all construction, post-Project and operational phases of the development. |
|
|
i) Implementation
schedules, summarising
all
recommended mitigation measures. |
|
|
1.4.1.3 This
Manual is considered to be a working document and should be reviewed periodically and revised once substantial changes have been made.
1.5.1.1 For the purpose of this EM&A Manual, the Highways Department of the Hong
Kong SAR Government is
referred
to as the “Employer”
and the Project “Supervising Officer” defined
as the Supervising Officer’s Representative (SOR),
who
will
be responsible for the supervision of
the construction of the Project.
1.5.1.2 The mitigation/enhancement measures recommended by the TM-CLKL EIA that will require
a design audit or preparation
of
specifications
during the detailed
design phase of
the project will include:
-
bored piling monitoring programme (Not relevant to the Northern
Connection Sub-sea Tunnel Section); -
pre, during and post construction dolphin monitoring; -
250m dolphin exclusion zone for use during dredging, reclamation,
sheet and bored piling works; -
acoustic decoupling methods for use during reclamation and dredging
works; -
marine vessel control specifications; -
deployment of an artificial reef (Not
relevant to the Northern Connection Sub-sea Tunnel Section); -
installation of hoarding for the protection of the pitcher plants and
surrounding habitat (Not
relevant to the Northern Connection Sub-sea Tunnel Section); -
coral translocation; -
design of toll plaza for grave G1 set back and protection (Not
relevant to the Northern Connection Sub-sea Tunnel Section); and -
landscape design drawings. |
1.5.1.3 In respect of the design phase EM&A, the
Consultant commissioned to undertake the Detailed Design contract will be
required to designate an auditor(s) to undertake the preparation of the design specifications
as detailed above, in addition to an environmental audit of the design of the
specified landscape measures in order to ensure that the recommendations of the
EIA have been fully and properly specified.
The Consultant shall use suitably qualified staff to undertake the audit
requirements to the satisfaction of the EPD and the AFCD as appropriate. A flow chart of the design phase EM&A
procedures is shown in Figure 1.1.
1.5.1.4 During the construction and operational phases of the project, an Environmental
Team (ET) is to be employed by the Contractor. The ET will be headed by an Environmental
Team Leader (ETL). He shall
ensure
the Contractor’s compliance with the project’s
environmental
performance requirements
during construction and undertake the post construction EM&A works and his responsibilities will
include field
measurements, sampling, analysis
of monitoring results, reporting and auditing.
The ETL shall be approved by the SOR
and
the Director of Environmental
Protection (DEP) and shall be competent and shall have at least 7
years relevant
environmental monitoring and audit experience
on
projects of a
similar scale and nature.
1.5.1.5 The ET will comprise suitably qualified support staff to carrying out the EM&A
programme. The ET shall be independent and shall not be in any way connected to the Contractor’s company. Due to the specialist nature of some of the EM&A
works
required for this project,
the ET should comprise professionals proficient to undertake the tasks involved.
Thus, the ET should include personnel experienced in noise, dust and water quality monitoring and mitigation, supervision of waste
management,
compensatory tree planting, coral relocation and dolphin monitoring
and
supervision.
1.5.1.6 Accordingly, a qualified dolphin specialist(s), together with a suitably experienced team of dolphin spotters, and a coral specialist, to the satisfaction of AFCD, will be required as part of
the ET to undertake the dolphin abundance monitoring, implement the dolphin exclusion zones and undertake the coral relocation process. In addition,
a Registered Landscape Architect, as defined by the Landscape Architect’s Registration Board, will be required on the ET to monitor and audit
the landscaping installation works and assist in the audit of the ecological transplantation and restoration works.
1.5.1.7 The overall duties of ETL and the team are as follows:
-
Sampling, analysis and statistical
evaluation
of monitoring
parameters
with reference to the EIA study recommendations
and requirements in respect of
noise, dust and water quality. -
Environmental site surveillance -
Audit of compliance with environmental protection and pollution
prevention and control regulations. -
Monitor the implementation of
environmental mitigation measures. -
Monitor compliance
with the environmental
protection
clauses/specifications in the Contract. -
Review construction programme and comment as necessary. -
Review construction methodology and comment as necessary. -
Complaint investigation,
evaluation and
identification of
corrective measures. -
Audit of the
-
Liaison with the
Independent Environmental Checker IEC)
on all environmental performance
matters. -
Advice to the Contractor on environmental improvement,
awareness, enhancement matter, etc., on site. -
Timely submission of the designated EM&A
reports to the SOR, the IEC, the DEP, the AFCD and the AMO as appropriate. |
1.5.1.8 In addition to the ETL and ET, an Independent Environmental
Checker (IEC) shall be employed to advise the SOR on environmental
issues related to the project. The role of the IEC shall be independent from the management
of
construction
works, but the IEC shall be empowered to audit the environmental performance of
the construction activities and operational mitigation.
The IEC shall have project management experience in addition to the requirements of the ET specified above and the appointment of the IEC will be subject to the approval
of the SOR and the
DEP. The IEC may require specialist support staff in order to properly carry out
his
duties, which shall include the following:
-
Review and audit all aspects of the EM&A
programme. -
Validate and confirm the accuracy of monitoring results,
monitoring equipment, monitoring locations, monitoring procedures and
locations of sensitive receivers. -
Carry out random sample check and audit on
monitoring data and sampling procedures, etc. -
Conduct random site inspection. -
Audit the EIA recommendations and requirements
against the status of implementation of environmental protection measures on
site. -
Review the effectiveness of environmental mitigation
measures and project environmental performance. -
Audit the Contractor’s construction methodology and
agree the least impact alternative in consultation with the ET and the
Contractor. -
Check complaint cases and the effectiveness of
corrective measures. -
Review EM&A report submitted by the ET. -
Feedback audit results to ET by signing off relevant
EM&A proformas. |
1.5.1.9 An
organisation chart showing the lines of communication
between
the
key parties with respect to the EM&A
works is provided on Figure 1.2. Both the ET
and IEC shall be retained for the duration of the EM&A works which will span both the construction phase and one year into the operational phase of the project. The operational EM&A works will be the responsibility of the Contractor and will
be
undertaken in parallel to the maintenance period after the completion of
construction.
1.5.1.10 Notwithstanding the above, given that the TM-CLKL, HKBCF and HKLR will be
constructed concurrently, an
Environmental Project Office (ENPO)
or equivalent to oversee the cumulative construction projects in North Lantau area will be established by the Project Proponent. The responsibility of the ENPO would be similar to that of
the IEC but should also include:
-
coordination of the monitoring and auditing works
for all the on-going projects in the area in order to identify possible sources/causes
of exceedances and recommend suitable remedial actions where appropriate; -
identify and assess cumulative impacts including
possible sources/causes of exceedance and recommending suitable remedial
actions; -
undertake liaison with the mainland project teams
counterparts to identify and assess any cross-boundary cumulative impacts;
and -
coordinate the assessment and response to
complaints/enquires from locals, green groups, district councils or the
public at large. |
1.5.1.11 The exact responsibilities and organisation of the ENPO will be defined during the
detailed design stage.
1.6.1.1 To clarify the terminology for
impact monitoring and audit, key definitions are specified below and are used
throughout this Manual.
1.6.1.2 Monitoring refers to the systematic
collection of data through a series of repetitive measurements. The stages of monitoring are defined in this
document as follows:
a) Baseline Monitoring refers to the measurement of parameters, such
as noise and air quality impact parameters, during a representative
pre-project period for the purpose of determining the nature and ranges of
natural variation and to establish, where appropriate, the nature of change. b) Impact Monitoring involves the measurement of environmental
impact parameters, such as noise and air quality, during Project construction
and implementation so as to detect changes in these parameters which can be
attributed to the Project. |
1.6.1.3 Audit is a term that infers the verification
of a practice and certification of data.
The types of audit are defined below:
a) Compliance audit is defined as follows: · the
process of verification that all or selected parameters measured by a noise or
air quality impact monitoring programme or levels of an operation are in
compliance with regulatory requirements and internal policies and standards;
and · the
determination of the degree and scope of any necessary remediation in the
event of exceedance of compliance. b) Post Project Audit is carried out after the implementation and
commissioning of a Project. |
1.6.1.4 For the purpose of noise, air and
water quality impact monitoring and audit, the Action and Limit Levels are
defined as follows:
a) The Action Level is the level defined in which there is an
indication of a deteriorating ambient level for which a typical response could
be an increase in the monitoring frequency.
b) The Limit Level is the level beyond the appropriate remedial
pollution control ordinances, noise and air quality impact objectives or Hong
Kong Planning Standards and Guidelines established by the EPD for a particular
project, such that the works should not proceed without appropriate remedial
action, including a critical review of plant and work methods.
2.1.1.1 Further to the recommendations
of the Option
Assessment and
subsequent alignment developments detailed in Section 2 of the EIA report, the preferred TM-CLKL
scheme comprises
Northern Connection
Option
N1b,
Main Connection
Option M3 and
Southern
Connection
Option S1. This preferred alignment
is shown in Figure 2.1 and will comprise:
(a) construction of approximately 5.0 km long dual 2-lane road tunnel between Tuen Mun Area 40 and the HZMB HKBCF at north-east of HKIA;
(b) construction of approximately 4.2km seawalls and approximately 35.6 ha of reclamation
to
the Government foreshore and
sea-bed
at Tuen Mun
Area 40 and Lantau for the tunnel portals
and
the associated roads,
as shown in Figures 2.2a and 2.2b;
(c) construction of approximately 1.6km
long dual 2-lane viaduct between HZMB HKBCF and NLH and the associated roads at Tai Ho;
(d) construction of a toll plaza at Tuen Mun Area 46 and the associated roads at
Tuen Mun;
(e) construction of footpaths areas;
(f) construction
of administration
building, ventilation
buildings and other
ancillary buildings to facilitate ventilation and tunnel control
operation serving the proposed road tunnel in (a) above and toll plaza in (d) above;
(g) modification and realignment of sections of
(h) modification
and realignment
of
sections of
(i) permanent closure
and demolition of
sections
of
existing at-grade
carriageways, footpaths and central median/refuge islands;
(j) temporary closure and reconstruction/modifications of sections of existing at-grade carriageways, footpaths and central median/refuge islands; and
(k) ancillary
works including site formation,
slope, drainage,
utilities, footbridge, noise barriers, retaining walls, berths and temporary pontoon.
2.1.1.2 Details of the various elements of the selected TM-CLKL alignment are detailed
in
the sections below.
2.2.1.1 At the northern landfall in Tuen Mun, adjacent to the River Trade Terminal at
Pillar Point, the construction of TM-CLKL requires a reclamation of about 16.5
ha of land area when calculated to the cope line, or 21.1
ha of land for the footprint
area to the bottom of the seawall where
it intersects the seabed.
The general layout and typical sections of the proposed reclamation scheme in this location are shown in Figures 2.3a to 2.3c.
2.2.1.2 Unlike the southern landfall
reclamation where sand
fill is proposed below +2.5mPD, public fill will be used for the entire reclamation to maximize the use of public fill. Though
this may result in
worse
impact to water quality
during
construction,
in view of
its
relatively smaller scale in
comparison with
the
HKBCF
reclamation, the type of fill material
is
adopted to achieve
an
overall
balance among environmental, technical and other aspects.
2.2.1.3 The northern landfall
reclamation is essentially required to provide a land area for construction of the launching shaft for the tunnel
boring machine
(TBM) and ultimately, protection to the tunnel structure when constructed.
2.2.1.4 During the detailed
design phase of the Contract, the latest development of the tunnels’ design
requires Portion N-a of the reclamation to be ready first in order to reduce
the construction risks. The latest
construction sequence is presented in Annex C. Under the latest sequence, it is proposed to
commence reclamation at Portion N-a, followed by reclamation at Portions N-b
and N-c, which is a reverse of the original sequence of the EIA Report and
EP-354/2009A. The latest construction sequence has been
proposed and a Notification of Changes in
Construction Sequence (the “Notification”) was submitted to EPD on 25
September 2013. Summary of the
Notification is presented in Annex C. Sand Compaction Piles (SCP), in association with a non-dredged seawall foundation, have been considered
for
the
construction
in order
to minimise the amount of
marine
sediment to
be dredged, as described
in
Section 2. However, these techniques require a much longer
construction time for the seawall
which would
not be quick enough to
allow the land to be formed on time to allow the TBM to commence tunnel
construction. Therefore, a fully
dredged method is required for the seawall foundation construction. The southern tip of the reclamation will
house the TBM tunnel shaft and the deeper portion of the cut-and-cover tunnel
section. The marine deposits located
above these deep structures would inevitably have been removed during
excavation for the construction of these structures. Fully dredged method is therefore also
proposed for this section of the reclamation in conjunction with the seawall
construction.
2.2.1.5 Notwithstanding, a non-dredged reclamation is proposed for the inner portions of
the
reclamation
denoted
by N-a and N-b
(Figures 2.3a and
2.3b). In
these
sections of the alignment, the cut-and-cover tunnel and open ramp will lie above the marine
deposits layer and, in order to minimise the sediment
removal and disposal quantities, it is proposed that the marine deposits underneath the cut-and-
cover tunnel and ramp be left in place, with the tunnel structures supported by deep
foundation and diaphragm walls, where necessary.
Band drains and sand blankets will be installed and surcharging will be applied to reduce the residual
ground settlement associated with the non-dredged reclamation.
2.2.1.6 Construction of the northern reclamation, which partly abuts the existing seawall at Pillar Point, will affect the marine operations of the Government Berths at Tuen Mun River Trade Terminal, including Customs and
Excise (C&E) and Immigration (ImmD)
Departments
and
Fire Services Department’s
(FSD)
Fire Boat Station. Provisions have been made to relocate these facilities to the new
reclamation alongside the eastern seawall (see Figure 2.2a).
2.2.2.1 An elevated viaduct at the northern section of
TM-CLKL connects the submarine tunnel as it emerges on the northern landfall to the south of the TMWB alignment at
the
north.
Commencing
from
the
reclamation
for
the
tunnel landfall,
the
viaduct curves up and over Lung Mun Road, crossing above a sawmill factory and
then abuts to the retaining wall structures at the western side of
the proposed toll plaza in Area 46, as described in Section 2.2.3 below. Layout of the viaduct is shown in Figure 2.4.
2.2.2.2 The structural form of the viaduct will consist of a pair of pre-stressed concrete
box girders supported on reinforced concrete piers. Each box girder commences
at around 14.6 m
wide at the reclamation to accommodate a 2-lane carriageway, before widening out to accommodate additional lanes for connection with
the toll plaza.
Span lengths will typically be 60m using a constant structural deck depth of 3.2 m.
In order to cross over the
2.2.3.1 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.2 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.3 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.4 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.5 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.6 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.7 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.8 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.9 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.10 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.11 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.3.12 Not
relevant to the Northern Connection Sub-sea Tunnel Section.
2.2.4.1 Site