1                      INTRODUCTION                                                                          

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                      Project Description                                                           

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                      Air Quality                                                                                

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                      Water Quality                                                                        

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                      Cultural Heritage                                                              

9.1                   Introduction                                                                          

10                    Landfill Gas Hazard Assessment                                

10.1                 Introduction                                                                          

11                    Site Environmental Audit                                                 

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     

Annex A       Silt Curtain Arrangements

Annex B       Figures

Annex C       Summary of Notification of Changes in Construction Sequence

Annex D       Summary of Changes

Appendix A      Environmental Mitigation and Enhancement Measure Implementation Schedules

Appendix B      Environmental Proformas


1                                            INTRODUCTION

1.1                                      Background Information             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 Hong Kong – Zhuhai – Macao Bridge (HZMB).   In order to cope with the anticipated traffic demand, two new connections between NWNT and North Lantau – Tuen Mun – Chek Lap Kok Link (TM-CLKL) and Tuen Mun Western Bypass (TMWB) are proposed.             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 North Lantau at its southern side.             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.             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.             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 Hong Kong-Zhuhai- Macao Bridge (HZMB) and Hong Kong Boundary Crossing Facilities (HKBCF), it was decided to integrate the TM-CLKL southern landfall reclamation with the HKBCF reclamation.   It was considered that this arrangement would also provide a cost-effective connection between the HKBCF and North Lantau.   Following a full option assessment, the preferred scheme was selected, as detailed in Section 2 of this EM&A Manual.             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.             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.          The Hong Kong SAR Government’s applicable environmental regulations for noise, air quality, ecology, water quality, landscape and visual resources and waste management and heritage protection, the Hong Kong Planning Standards and Guidelines and recommendations in the TM-CLKL EIA Report have served as guidance documents in the preparation of this Manual.   This EM&A Manual fulfills the requirements of the Study Agreement and follows the approach recommended in EPD’s Generic EM&A Manual, Annex 21 of the Technical Memorandum on the EIA Process and EM&A Guidelines for Development Projects in Hong Kong.

1.2                                      Policy                          The Supervising Officers 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                                      EM&A Programme Objectives             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.             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.             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


EM&A Phase


Construction Phase

Operational Phase

Air Quality





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.





Water Quality




Landscape and Visual




Waste/ Contaminated Land




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                                      Scope of the EM&A Programme                   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:



i)            Establish baseline dust levels at specified locations and review these levels on a regular basis.



ii)           Implement construction dust impact monitoring programme.



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).



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.



i)            Implement construction phase audit requirements for waste aspects.



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 Contractors general environmental awareness;



·          the Contractors implementation of the recommendations in the EIA;



·          the Contractors 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.                                                   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.             This Manual is considered to be a working document and should be reviewed periodically and revised once substantial changes have been made.

1.5                                      Project Organization             For the purpose of this EM&A Manual, the Highways Department of the Hong Kong SAR Government is referred to as the Employerand 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.             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.             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.             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 Contractors 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.             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.             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.                                                   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 EMS and recommend and implement any changes as appropriate.

-        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.             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.             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.           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.           The exact responsibilities and organisation of the ENPO will be defined during the detailed design stage.

1.6                                      Terminology             To clarify the terminology for impact monitoring and audit, key definitions are specified below and are used throughout this Manual.             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.             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.             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                                            Project Description

2.1                                      Scope of the Project          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 Lung Fu Road and Lung Mun Road at Tuen Mun;

(h)    modification and realignment of sections of North Lantau Highway and Cheung Tung Road at Tai Ho;

(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.             Details of the various elements of the selected TM-CLKL alignment are detailed in the sections below.

2.2                                      Northern Section in Tuen Mun

2.2.1                                Northern Reclamation          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.              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.             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.             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.             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.          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 Departments (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                                Viaduct Connection and Slip Roads             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.             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 Lung Mun Road and the existing fire station, slightly longer spans of around 75m are used with a haunched deck of a depth of around 6m at the piers.   The piers supporting the viaducts will sit on bored piles founded on rock at some 20m below ground level, with pile caps below ground level.

2.2.3                                Toll Plaza          Not relevant to the Northern Connection Sub-sea Tunnel Section.          Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.             Not relevant to the Northern Connection Sub-sea Tunnel Section.           Not relevant to the Northern Connection Sub-sea Tunnel Section.           Not relevant to the Northern Connection Sub-sea Tunnel Section.           Not relevant to the Northern Connection Sub-sea Tunnel Section.

2.2.4                                Other Construction Works             Site