TABLE OF CONTENTS

 

1.         INTRODUCTION.. 1

1.1       Background. 1

1.2       Project Objectives. 1

1.3       Nature of the Project 1

1.4       Purpose of EIA Study. 1

1.5       The Approach. 1

1.6       Mitigation Measures. 2

1.7       Reference to Relevant Study. 2

1.8       Scope of Key Environmental Issues. 2

2.         description of the project.. 4

2.1       Location and Description of the Project 4

2.2       Identification of the Project Need. 4

2.3       Considerations for Design Options. 5

2.4       Alternative Options for Entrance and Subway Alignment 9

2.5       Considerations of Alternative Construction Methods. 10

2.6       The Preferred Scheme. 10

2.7       Implementation and Planning of the Proposed Project 13

3.         construction air quality impact.. 14

3.1       Introduction. 14

3.2       Environmental Legislation, Standards and Guidelines. 14

3.3       Description of the Environment 15

3.4       Air Sensitive Receivers. 15

3.5       Identification of Pollutant Sources. 16

3.6       Assessment Methodology. 17

3.7       TSP Daily Concentration. 19

3.8       Evaluation of Impacts. 19

3.9       Cumulative Impacts. 20

3.10     Mitigation of Adverse Environmental Impacts. 20

3.11     Evaluation of Residual Impacts. 21

3.12     Environmental Monitoring and Audit 21

4.         NOISE IMPACT.. 22

4.1       Introduction. 22

4.2       Environmental Legislation, Policies, Plans, Standards and Criteria. 22

4.3       Construction Noise – General Construction Works. 22

4.4       Fixed Noise in Operation Phase. 24

4.5       Noise Sensitive Receivers. 24

4.6       Assessment Methodology. 26

4.7       Identification of Environmental Impacts. 29

4.8       Prediction and Evaluation of Environmental Impacts. 29

4.9       Mitigation of Adverse Environmental Impacts. 31

4.10     Evaluation of Residual Impacts. 34

4.11     Environmental Monitoring and Audit 37

4.12     Conclusion. 37

5.         construction water quality impact.. 39

5.1       General 39

5.2       Environmental Legislation and Standards. 39

5.3       Environmental Impact Assessment Ordinance (EIAO), Cap. 499, S.16. 39

5.4       Water Pollution Control Ordinance (WPCO) 39

5.5       Technical Memorandum.. 40

5.6       Practice Notes. 41

5.7       Baseline Condition. 41

5.8       Assessment Methodology. 42

5.9       Identification of Water Sensitive Receivers. 42

5.10     Potential Sources from Construction Activities. 42

5.11     Evaluation of Potential Water Quality Impacts. 43

5.12     General Construction Site Activities. 44

5.13     Mitigation Measures. 44

5.14     General Construction Site Activities. 46

5.15     Evaluation of Residual Impacts. 46

5.16     Environmental Monitoring and Audit 46

5.17     Conclusions. 46

6.         waste management.. 47

6.1       Introduction. 47

6.2       Environmental Legislation and Standards. 47

6.3       Waste Management 47

6.4       Construction and Demolition (C&D) Materials. 48

6.5       Assessment Methodology. 48

6.6       Prediction and Evaluation of Environmental Impacts. 48

6.7       Mitigation Measures. 51

6.8       Evaluation of Residual Impacts. 52

6.9       Environmental Audit 53

6.10     Conclusion. 53

7.         Landscape and Visual Impact assessment.. 54

7.1       Introduction. 54

7.2       Environmental Legislation, Standards and Guidelines. 54

7.3       Assessment Methodology. 55

7.4       Scope and Content of the Study. 59

7.5       Review of Planning and Development Control Framework. 59

7.6       Baseline Study. 60

7.7       Landscape Impact Assessment 64

7.8       Visual Impact Assessment 71

7.9       Conclusion. 77

8.         BUILT HERITAGE IMPACT ASSESSMENT.. 78

8.1       Introduction. 78

8.2       Environmental Legislation and Standards. 78

8.3       Assessment Methodology. 79

8.4       Results of the Desk Based Study. 80

8.5       Results of the Field Survey. 82

8.6       Prediction and Identification of Impacts. 82

8.7       Evaluation of Impacts. 83

8.8       Mitigation Recommendations. 85

8.9       Conclusions. 85

9.         environmental monitoring and audit (EM&A) Requirements.. 86

9.1       Introduction. 86

9.2       Construction Air Quality Impact 86

9.3       Noise Impact 86

9.4       Construction Water Quality Impact 87

9.5       Waste Management 87

9.6       Landscape and Visual Impact 87

9.7       Built Heritage Impact 88

10.       ConclUsions And rEcommendations.. 89

 

 

LIST OF TABLES

Table 2.1               Summary of the Preferred Scheme

Table 2.2               Preliminary Construction Programme

Table 3.1               Hong Kong Air Quality Objectives

Table 3.2               Annual Average TSP Concentration in the Latest Five Years (Year 2002 – 2006) for Urban Development

Table 3.3               Details of Representative Air Sensitive Receivers

Table 3.4               Emission Factors for Construction Activities

Table 3.5               Predicted Maximum 1 - hour Average TSP Concentrations

Table 3.6               Predicted Maximum 24 - hour Average TSP Concentrations

Table 4.1               Daytime Construction Noise Criteria

Table 4.2               Acceptable Noise Levels

Table 4.3               Acceptable Noise Level for Fixed Plant Noise

Table 4.4               Summary of Representative Noise Sensitive Receivers

Table 4.5               Construction Tasks Involved

Table 4.6               Ventilation Shafts for the Proposed Project

Table 4.7               Summary of Unmitigated Construction Noise Levels at Representative NSRs During Normal Daytime Working Hours

Table 4.8               Summary of Max SWL for Each Ventilation Shaft

Table 4.9               Summary of Max SWL for Each Ventilation Shaft with Consideration of Cumulative Effect

Table 4.10             Quieter PME Recommended for Adoption during Construction Phase

Table 4.11             Noise Mitigation Measures for Certain PME during Construction Phase

Table 4.12             Mitigated Construction Noise Levels

Table 4.13             Construction Noise Residual Impacts

Table 4.14             Durations of Construction Noise Residual Impacts

Table 4.15             Construction Noise Residual Impacts at NSR N5

Table 5.1               Summary of Water Quality Objectives for Victoria Harbour WCZ

Table 5.2               Marine Water Quality of Victoria Harbour WCZ at the Selected Monitoring Station in 2006

Table 6.1               Estimated Quantities of C&D Materials

Table 7.1               Relationship between Receptor Sensitivity and Impact Magnitude in Defining Impact Significance

Table 7.2               List of the Landscape Resources and Their Sensitivity to Change

Table 7.3               Visual Sensitive Receivers (VSRs) and Their Sensitivity to Change

Table 7.4               Significant Landscape Impacts of the Proposed Works during Construction Phase

Table 7.5               Proposed Construction Phase Landscape Mitigation Measures

Table 7.6               Proposed Operation Phase Landscape Mitigation Measures

Table 7.7               Significance of Landscape Impacts in the Construction and Operation Phases

Table 7.8               Significance of Visual Impacts in the Construction and Operation Phases

Table 8.1               Distance of the Identified Resources in the Project Study Area from the Proposed Works

Table 10.1             Summary of Key Environmental Outcomes

 


LIST OF FIGURES

 

Figure 1.1             Site Layout Plan

Figure 1.2             Section A-A

Figure 1.3             Section B-B

Figure 1.4             Section C-C

Figure 1.5              Study Boundary for Air Quality, Noise and Water Quality Assessment

Figure 2.1             Construction Sequence – Plant Basement

Figure 2.2             Construction Sequence – Satellite Concourse

Figure 3.1             Locations of Representative Air Sensitive Receivers

Figure 3.2              Contours of Maximum 1-Hour Average TSP Concentration at 1.5m Above Ground

Figure 3.3              Contours of Maximum 24-Hour Average TSP Concentration at 1.5m Above Ground

Figure 4.1             Locations of Representative Noise Sensitive Receivers

Figure 4.2             Schematic Diagram Showing Typical Site Arrangement

Figure 4.3             Schematic Diagram Showing Typical Site Arrangement

Figure 4.4             Assumed Worst Locations of Ventilation Shaft Openings

Figure 5.1              Locations of Marine Water Quality Monitoring Stations in Victoria Harbour WCZ (VM5 & VM6)

Figure 7.1              Landscape and Visual Impact Study Area

Figure 7.2              Baseline Landscape Resources

Figure 7.2.1           Baseline Landscape Resources Photos

Figure 7.2.2           Baseline Landscape Resources Photos

Figure 7.2.3           Baseline Landscape Resources Photos

Figure 7.2A            Aerial Photograph Showing Baseline Landscape Characters and Resources

Figure 7.3              Key VSRs and Zone of Visual Influence During Construction and Operation

Figure 7.3.1           Baseline VSRs Photos

Figure 7.3.2           Baseline VSRs Photos

Figure 7.4              Propose Landscape Mitigation Measure

Figure 7.4.1           Photomontage A

Figure 7.4.2           Photomontage B

Figure 7.4.3           Photomontage C

Figure 8.1              Enhanced Entrance A1

Figure 8.2              Enhanced Entrance A1 (View from NE Corner)

 

LIST OF APPENDICES

Appendix 3.1         Construction Dust Emission Factors

Appendix 4.1         Photographs of Representative Noise Sensitive Receivers

Appendix 4.2         Plant Inventory for Construction Noise Assessment (Unmitigated)

Appendix 4.3         Calculation of Construction Noise Levels at Representative Noise Sensitive Receivers During Normal Daytime Working Hours (Unmitigated Scenario)

Appendix 4.4         Plant Inventory for Construction Noise Assessment (Mitigated)

Appendix 4.5         Calculation of Construction Noise Levels at Representative Noise Sensitive Receivers During Normal Daytime Working Hours (Mitigated Scenario)

Appendix 8.1         Figures of Built Heritage Impact Assessment

Appendix 8.2         Catalogue of the resources surveyed for the Project

Appendix 8.3         Photographs of the existing environment

Appendix 10.1       Implementation Schedule of the Proposed Mitigation Measures

 

References

 

AMO Files                   AM88-0397 St. Andrew’s Church Compound

                                    AM77-0026 Hong Kong Observatory

                                    AM84-0335 Former Kowloon British School

                                    AM97-0890(05) Whitfield Barracks West Kowloon II Battery

                                    AM97-0890(04) Whitfield Barracks Block S62

                                    AM97-0890(03) Whitfield Barracks Block S61

                                    AM97-0890(02) Whitfield Barracks Block  S4

                                    AM97-0890(01) Whitfield Barracks Block S58

                                    AM77-0006 Signal Tower, Signal Hill (Tai Pau Mei)

                                    AM77-0010 Former Marine Police Headquarters

 

Hayes, J      1966                   Old British Kowloon, Journal of the Hong Kong Royal Asiatic Society, Vol VI pp.120-137

 

Rodwell, S    1992                   Historic Hong Kong: A Visitor’s Guide, The Guidebook Company Ltd/ Hong Kong tourist Association, Hong Kong

 

 


Abbreviation

 

 

AMO             Antiquities and Monuments Office

 

E&M             Electrical and mechanical

 

ETS              East Tsim Sha Tsui Station

 

HEER           Health Education Exhibition and Resource Centre

 

HM                Hotel Miramar

 

KSL              Kowloon Southern Link

 

MSC             Miramar Shopping Centre

 

MTRCL         Mass Transit Railway Corporation Limited

 

OVT              Old and Valuable Tree

 

Subway MSC      Subway connecting the Satellite Concourse and Miramar Shopping Centre

 

Subway TST       Subway connecting the Satellite Concourse and Tsim Sha Tsui Station

 

TNS              Tsim Sha Tsui Station Northern Subway

 

TST              Tsim Sha Tsui Station

 

TWL             Mass Transit Railway Tsuen Wan Line

 

TYB              Tung Ying Building

 

 

 

 


1.                              INTRODUCTION

1.1                         Background

1.1.1                    The title of this project is known as Tsim Sha Tsui Station Northern Subway” (TNS) (hereafter known as the Project).  The Project Proponent is MTR Corporation Limited (MTRCL).  ENSR Asia (HK) Limited has been commissioned to carry out an Environmental Impact Assessment Study for the Project.

1.2                         Project Objectives

1.2.1                    The objectives of this Project are to provide passengers with a direct and accessible safe pedestrian subway in addition to the existing entrances and to relieve the existing busy northern concourse and platform areas of Tsim Sha Tsui (TST) Station by providing a new direct high-capacity corridor for effective passenger access. The location of the proposed Project is shown in Figure 1.1.  Three cross sections of the Project are shown in Figures 1.2 to 1.4.

1.3                         Nature of the Project

1.3.1                    The Project is classified as a Designated Project under Category A.2 (A railway and its associated stations) of Part 1, Schedule 2 of the EIAO.

1.3.2                    The Project involves construction and operation of (i) An underground pedestrian subway link that connects the north end of the TST Station platform with integrated entrances in the basements of the Tung Ying Building Redevelopment, Miramar Hotel and Miramar Shopping Centre; (ii) An underground satellite concourse underneath Nathan Road located adjacent to Tung Ying Building and the Miramar Hotel; and (iii) A new plant basement near existing Entrance A1 to house the station equipment relocated from the north end of TST Station for accommodating the TNS connection.

1.4                         Purpose of EIA Study

1.4.1                    The purpose of this EIA Study is to provide information on the nature and extent of environmental impacts arising from the construction and operation of the proposed subway works, and to contribute to decisions on the overall acceptability of the Project, after the implementation of proposed mitigation measures.

1.5                         The Approach

1.5.1                    The EIA study has been prepared in accordance to the EIA Study Brief (No. ESB-168/2007) and the guidelines provided in Annex 11 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) for the report contents and Annexes 12 to 19 for the impact assessments of various environmental issues.  The general approaches and methodologies adopted for this EIA study are described below.

Existing Environment Condition

1.5.2                    The characteristics of the existing environment were reviewed for identification and prediction of environmental impacts.  The baseline conditions of the key issues as identified in the EIA Study Brief including landscape & visual, noise, construction air and water quality and built heritage are described in the assessment.

Impacts Prediction

1.5.3                    The EIA Study was undertaken in accordance with the guidelines on assessment methodologies given in Annexes 12 to 19 of the EIAO-TM.

1.5.4                    Quantitative approach was adopted for assessing the construction noise impacts. The predictions were conducted based on well-proven, internationally accepted methods.

1.5.5                    The applied methodologies for the Project had previously been adopted in other EIA studies.  They have been generally accepted for use in predicting environmental impacts and for comparison of assessment results with the EIAO-TM requirements.  Limitations are however envisaged of these methodologies. The accuracy of the prediction result will be affected by uncertainty in input data such as sound power levels of construction plants to be used on-site.  The most realistic data have been used in the prediction in order to provide a result with the lowest practicable quantitative uncertainty.

1.6                         Mitigation Measures

1.6.1                    Mitigation measures are proposed to alleviate the potential impacts predicted. The proposed mitigation measures have previously been adopted in other environmental assessment studies with similar construction works.  An Environmental Monitoring and Audit programme is recommended to ensure that the recommended mitigation measures can effectively mitigate the impacts so as to comply with the corresponding criteria.

1.7                         Reference to Relevant Study

1.7.1                    The EIA Study was made reference to the approved relevant EIA Study Modifications to MTRCL Tsim Sha Tsui Station, Mass Transit Railway Corporation Limited (EIAO Register No.: AEIAR-043/2001).

1.8                         Scope of Key Environmental Issues

1.8.1                    The identified key environmental issues regarding the construction of the proposed Project are listed as below:

·               potential construction dust impacts to nearby sensitive receivers from the Project;

·               potential construction and operation noise impacts to nearby sensitive receivers from the Project;

·               potential construction water quality impacts to nearby sensitive receivers, as well as waste management implications, from the Project;

·               potential landscape and visual impacts to nearby sensitive receivers from the Project during its construction and operation stages;

·               potential impacts to nearby identified heritage resources from the Project during its construction and operation stages; and

·               potential cumulative impacts to nearby sensitive receivers for the above key issues, taking into account the existing construction works is discussed in Section 2.

1.8.2                    The assessments of these key environmental issues are to be discussed in the following chapters of this Report. The study boundaries of construction air quality, noise and construction water quality impacts are shown in Figure 1.5.

1.8.3                    The Project is within a developed urban area, there are no ecological sensitive receivers, such as Sites of Special Scientific Interest (SSSIs), Fish Culture Zones and Marine Parks and/or Reserves and other areas of ecological importance or conservation interest, within or in the immediate vicinity of the site area.  Ecological impacts are, therefore, not expected during the construction and operation phases of the proposed Project.  Accordingly ecological impact assessment is not required in this EIA Study.

 

 


2.                              description of the project

2.1                         Location and Description of the Project

2.1.1                    The Project is located in Tsim Sha Tsui district which is an urban area with mixture of commercial and residential developments.  The proposed works lie along Nathan Road from Cameron Road junction to Miramar Shopping Centre near Kimberley Road.  The proposed new plant basement will be located under the existing Entrance A1 of the TST Station. 

2.1.2                    The project includes the following:

·               A subway (Subway TST) from the north end of TST Station, running approximate 85m under Nathan Road to a Satellite Concourse;

·               A satellite concourse (45m approx) underneath Nathan Road located adjacent to Tung Ying Building and the Miramar Hotel;

·               A subway (Subway MSC) from the north end of the Satellite Concourse, running approximate 80m under Nathan Road to the Miramar Shopping Centre (MSC).

2.2                         Identification of the Project Need

2.2.1                    The passenger forecast study has established that the north of TST Station is under the most pressure and is now already approaching capacity.  This is because the station catchment areas of the northern section are relatively more developed and will have more re-development.  The northern section of the station is already and is expected to continue to be overloaded, especially at the vertical links between concourse and street at Entrances A1 (to Nathan Road and Haiphong Road), B1 and B2 (to Nathan Road and Cameron Road).  Without any modification works, the north end of the station concourse will become significantly overloaded in the next few years.

2.2.2                    The proposed subway will provide a direct link for passengers between the platform at the north end of the TST Station to a satellite concourse with access to street level via subway connections to the Tung Ying Building Redevelopment, Miramar Hotel, and Miramar Shopping Centre. Passengers can access the development areas north-east of TST, thus avoiding congestion and a number of signalled pedestrian crossings at street level.

2.2.3                    TNS will provide an attractive route for existing and future passengers as it will enhance the walking quality, and provide a fast, safe, air-conditioned and weather proof route between the station and the catchment north of Tsim Sha Tsui avoiding Entrances A1, B1 and B2 of TST Station and traffic and pedestrian congestion at street level.

2.2.4                    In the absence of the project, in the longer term the TST Station would remain busy and its congested sections would remain saturated.  This strongly implies that the station is in need of a significant operational relief in its northern section, despite the launching of the Kowloon Southern Link (KSL) in year 2009, and the passenger diversion that it may cause.

2.2.5                    The TNS scheme is also complementary with a number of pedestrian schemes and traffic calming measures implemented by the Government of the HKSAR in the area west of Nathan Road to improve the whole pedestrian environment.  These include Haiphong Road, Canton Road, Peking Road, Hankow Road, Lock Road and Ashley Road modification schemes.  As these schemes have been well received by the public, further schemes are in progress to implement even more comprehensive measures to regulate both vehicular and pedestrian traffic to achieve a better environment in the whole Tsim Sha Tsui area.

·               Those projects include:

·               Greening Master Plan (GMP) for TST Area by Civil Engineering Development Department (CEDD); and

·               Area Improvement Plan (AIP) for TST Area by Transport Department (TD).

2.2.6                    Since the opening of East Tsim Sha Tsui (ETS) Station and the new pedestrian connections to TST Station, it has provided rail and non rail users a direct and convenient interchange to/from MTR stations, relieving congestion at the busy street level and enhancing the walking environment in Tsim Sha Tsui.  In the next few years, this subway network is to be expanded to include the Middle Road Subway Extension to Peking Road extending the railway catchment to the south west of Tsim Sha Tsui.  With both the ETS related pedestrian links in TST south and the TNS scheme in TST north completed, the TST District can be comprehensively served with good pedestrian connectivity and accessibility along both sides of Nathan Road.

2.2.7                    To conclude, this station improvement scheme would provide much-needed relief to the currently congested Entrances A1 (to Haiphong Road) and B1 & B2 (to Cameron Road).  Without such relief, these two northern entrances would continue to suffer from heavy operational pressure, especially with the continuous TST catchment growth following the airport relocation and the subsequent relaxation of building height/massing constraints in south Kowloon.

2.3                         Considerations for Design Options

2.3.1                    In 2006, MTRCL commenced the planning of a new capacity enhancement scheme to relieve the northern section of the TST Station.  This is known as the Tsim Sha Tsui Station Northern Subway (TNS) and is the subject of this submission.  This scheme consists of an underground pedestrian subway link (TNS) that connects the northern end of the TST Station platform, via the modified concourse plant room area, with integrated entrances in the basements of Tung Ying Building Redevelopment, Miramar Hotel and the Miramar Shopping Centre together with an underground satellite concourse (the Satellite Concourse) in the middle of the subway.

Considerations for TNS Subway Alignment

2.3.2                    The two prime objectives to be achieved in the planning of the TNS subway include:

·               to provide a direct pedestrian subway link between the TST Station and the Tung Ying Building Redevelopment, Hotel Miramar and Miramar Shopping Centre;

·               to accommodate the existing plant rooms displaced from the TST Station by the TNS subway link.

2.3.3                    The key objective is to minimise the walking distance as far as practicable. Obviously, if the alignment of the pedestrian subway is not attractive to the passengers, the purpose of building it will be defeated.  In planning the subway alignment, there are several key considerations for its layout and the form that it might take.  The major constraints on the design and construction of the proposed subway identified are as follows:

·               Clearance requirements to the Tsuen Wan Line (TWL) Tunnels and structures;

·               Minimum disturbances to the existing water mains, utilities and drainage systems;

·               Interface with the redevelopment works of Tung Ying Building (TYB);

·               Interfaces with Hotel Miramar (HM) and Miramar Shopping Centre (MSC), both in use during construction;

·               Interface with MTR TST Station and the need to minimise any impacts on the functionality of key public and plant room areas;

·               Limited works area and construction access;

·               Land availability and projections from buildings;

·               Vehicular and Pedestrian Traffic Management during construction;

·               Landscape and visual impacts for any above ground structures;

·               Minimal disturbance to Old and Valuable Trees (OVTs) and trees of landscape value; and

·               Minimum noise and dust nuisance to the public and residents during construction.

TNS Subway Alignment

2.3.4                    In identifying the above constraints, the preferred alignment of the subway has been developed to provide:

·               a shallow and broad subway;

·               a vertical alignment that is as flat as possible, the ideal conditions for pedestrians comfort and convenience;

·               Travelators to further enhance passenger convenience.

2.3.5                    As the vertical alignment of the subway is controlled by the need to connect into the TST Station and the basement of Tung Ying Building Redevelopment, Miramar Hotel and Miramar Shopping Centre, there is limited flexibility in adjusting the vertical alignment.

2.3.6                    The subway connects into the section north end wall at approximately 1m above existing concourse level to provide sufficient cover to the existing MTR running tunnels underneath.  To overcome any artificial obstructions, in the form of left-in-place temporary piles and grout injection tubes, a Connection Chamber is located here to be built by cut-and-cover method.  The Connection Chamber is a buried underground structure with no permanent impacts at ground or above-ground level.

2.3.7                    The north end of the existing TST Station is to be modified to accommodate the passageway to Subway TST (the southern section of the subway between the Satellite Concourse and TST Station).

New Plant Basement Options

2.3.8                    The connection between the Subway MSC (the northern section of the subway between Satellite Concourse and the Miramar Shopping Centre) and TST Station requires that the existing station E&M equipment from north-end plant rooms be re-located to provide a clear passageway to the platform.  There is no space in the existing station for the relocated E&M equipment.  By inspection of the surrounding area, the only vacant space near the station in which to construct a new Plant Basement to contain the displaced equipment from TST Station is in the vicinity of Entrance A1.

2.3.9                    In physical terms, the new plant basement is contained within a zone around Entrance A1 with the following structures and features surrounding it:

·               Heritage building, known as the Health Education Exhibition and Resource Centre (HEER) located north;

·               the old retaining wall at Haiphong Road;

·               existing TST Station Entrance A1 Adit and Ventilation Shaft Z located east;

·               the western wall of the TST Station and Nathan Road to the west; and

·               existing Entrance A2 Adit and Haiphong Road to the south.

2.3.10                The dimensions of the Plant Basement are constrained by the site environs (see above).  Options have been considered for both single-level and two-level basements.  The single level basement extended beyond the footpath of Haiphong Road was rejected based on unacceptable impacts to the existing structures nearby and the traffic on Haiphong Road.  A two-level basement was preferred as the layout was more compact and minimised impacts to the surrounding vehicular traffic and the existing structures including the heritage building nearby.

2.3.11                The plant basement will be ventilated through to the existing exhaust stack in Vent Shaft ‘Z’, in preference to constructing new ventilation shafts which would cause operational noise, visual and landscape impacts.

Entrance Options

General

2.3.12                In general, the above-ground entrances have the most potential impacts on noise, dust, visual and landscape to the public.  The entrance options discussed in the following section have different impacts on the immediate surrounding areas as follows:

Entrances Q1, Q2 and Q3

2.3.13                The three integrated entrances to the east of the satellite concourse (namely, Entrances Q1, Q2 and Q3) will have no permanent environmental impacts at ground and above-ground levels, with the only impacts being the underground connections to the basement levels of the adjoining buildings, namely, Tung Ying Building Redevelopment and the two existing Miramar Developments, Miramar Hotel and Miramar Shopping Centre.

2.3.14                As far as these buildings and their integrated MTR entrances are concerned, appropriate interior layout will be arranged such that any pedestrians can be fed to/from the respective buildings, and any by-passing passengers can walk effectively through these buildings for:

·               comfort of weather proof environment; and

·               convenient and direct access to the station’s platform avoiding the congested northern section at the station’s concourse level.

Entrances Q4 and Q5 on Park Lane Shopper’s Boulevard

2.3.15                To comply with statutory requirements for the emergency escape requirements from the subway.  It has been established that one emergency exit is required at the Satellite Concourse, the mid-point between the two subways.  A second emergency exit is required at the end of Subway MSC.  As emergency escapes routes can be upgraded to form entrances, a review of entrance options was undertaken on the western footpath of Nathan Road.  These entrances are all located in order to:

·               facilitate public accessibility to the station, the Kowloon Park or as a means of crossing Nathan Road; and

·               assist in evacuation from the underground subway.

2.3.16                The environmental considerations include the need to:

·               minimise noise and dust impacts during construction;

·               minimise the visual and landscape impacts during construction and operation;

·               minimise the nuisance to pedestrians during construction; and

·               avoid the large OVTs, and the assumed extent of their tree roots and tree canopies.

2.3.17                The entrance locations identified on the western footpath of Nathan Road include:

a)            An entrance located at the Kowloon Park entrance between the north and south blocks of Park Lane Shopper’s Boulevard;

b)            An entrance opposite the Miramar Shopping Centre; and

c)            An entrance opposite the proposed Satellite Concourse.

No further entrance options were identified, given the constraints found on the footpaths of Nathan Road.

2.3.18                The entrance scheme at Kowloon Park was not considered further due to construction impacts on the existing Kowloon Park stair structure where the electric equipment supporting the Park Lane Boulevard shops could not be temporarily re-provided during construction.

2.3.19                Substantial discussions had been held with Leisure and Cultural Services Department (LCSD) regarding the entrance options proposed on the footpath of Park Lane Boulevard opposite the Miramar Shopping Centre and the proposed Satellite Concourse.  Though due considerations have been given in the design and construction methodology of the entrances, it is concluded that the two entrance options on the footpath of Park Lane Boulevard were inappropriate in view of the potential impacts to the OVTs on the west side of Nathan Road and were not further pursued.

2.3.20                The ventilation shaft originally proposed to be integrated with one of the entrance on the footpath of Park Lane Boulevard will be incorporated with the Tung Ying Redevelopment and Hotel Miramar.

Emergency Exits

2.3.21                As mentioned earlier, two emergency exit points are required for the scheme, and as no entrances would be provided to street, the proposed emergency exits are dedicated escape routes only and not for public access.  Two locations identified are at the satellite concourse and at the end of the Subway MSC.

Emergency Exit at the Satellite Concourse

2.3.22                The emergency exit at the Satellite Concourse exits via the Tung Ying Building Redevelopment in a dedicated emergency corridor to street level.  The exit location to street is under study by the Tung Ying Building developer.

Emergency Exit at Subway MSC

2.3.23                The emergency exit is situated in the east footpath and planter of Nathan Road. It was placed well away from the OVT in the roadside planter in front of the Miramar Shopping Centre.  The footprint of the emergency exit was minimized to fit into the space at present occupied by young Ficus microcarpa (non-OVTs).  No other feasible locations have been identified due to the sever constraints found in the area.  To minimise any sight line problems and visual impacts, the above-ground structure is level with the existing planter and finished with materials to the adjacent planter to provide total integration.

Entrance A1 Upgrade

2.3.24                The existing canopy structure for Entrance A1 is approximately twenty-six years old.

2.3.25                The existing Entrance A1 canopy will be demolished during construction of the Plant Basement.  It will be replaced with an iconic transparent glass box, a distinctive station entrance that reinforces the Corporate image in Tsim Sha Tsui District.  The new Entrance A1 will improve access to the station with a disabled lift serving the Kowloon Park entrance, street level and the TST concourse level, a staircase and escalators from street level to the existing Entrance A1/A2 adit.

2.3.26                The transparent structure is intended to allow the new structure to blend in with the surrounding environment and minimise any landscape and visual impacts.

2.4                         Alternative Options for Entrance and Subway Alignment

2.4.1                    Alternative entrance locations and subway alignment are studied under the following constraints placed on this Project:

a)             Location of large OVTs and their assumed extend of root system near the project boundary;

b)            Requirement of an emergency escape/exit at the subway northern end;

c)            Requirement of an emergency escape/exit located at the mid-point between the existing TST station box and the northern end of the subway extension; and

d)            With the objective to minimise the walking distance as much as practicable; hence the shortest construction duration and the minimal environmental impacts.

2.4.2                    Alternative location for Entrance Q3 (proposed at the footpath of Park Lane Boulevard) has been reviewed.  Nevertheless, in view of the potential impacts to the OVTs on the west side of Nathan Road, it is concluded that lesser degree of environmental impact cannot be provided from any alternative due to the location constraint and thus not pursued further.

2.4.3                    For the subway alignment, the current alignment provides the shortest and the most direct connection between the existing TST Station & Satellite Concourse and between Satellite Concourse and the Miramar Shopping Centre, such that the environmental impact will be minimised.  Other alignment alternatives have been considered but all present additional environmental burdens from noise and dust due to longer or deeper subway alignment hence were not further pursued.

2.5                         Considerations of Alternative Construction Methods

2.5.1                    The construction of the TNS subway and associated structures is expected to be difficult, given the obvious need to minimise any environmental disturbance and impacts on the OVTs, traffic and pedestrian, residents, existing MTRCL Tsuen Wan Line (TWL) tunnels, TST Station and the nearby building structures.  Tunneling by mining method and cut-and-cover method are the available techniques to select from.  Based on the study, large proportion of the works under this project are to be constructed using tunneling by mining method, in which environmental impact will be minimised, only small proportion of works, where above ground construction works are inevitable are to be constructed by cut-and-cover method. 

2.5.2                    In order to minimise the environmental impacts and disturbance to the existing utilities and traffic along Nathan Road, the subway tunnels, which comprise a large proportion of the project, are to be constructed by using tunneling by mining method.  The alignment of the tunnels and ground conditions found in the project area are considered suitable for using tunneling by mining method based on the geological information provided by the geotechnical investigation carried out for this Project.

2.5.3                    For the small remaining proportion of works of this project, where above ground construction works are inevitable (such as area with limited soil cover and the need for access point for the works), the cut-and-cover method are to be adopted.  Nevertheless, cut-and-cover elements of the work have been limited as far as practicable to the Satellite Concourse, Connection Chamber, Plant Basement and the Emergency Exit stair. 

2.5.4                    Whenever cut-and-cover method is adopted, majority of construction works will be decked to reduce airborne noise, dust, visual and minimise traffic impacts which allow traffic to be diverted back over the excavation on Nathan Road.

2.5.5                    Other alternative construction method including open-cut excavation method has been reviewed.  Nevertheless, in view of large environmental impact will be created as compare with tunneling by mining method and cut-and-cover method, it is not recommended and thus not further pursued.

2.6                         The Preferred Scheme

2.6.1                    The site constraints, environmental factors and options available for the selection of the preferred scheme have been discussed in the above sections and are summarised below in Table 2.1:

Table 2.1        Summary of the Preferred Scheme

TNS Component

Scheme and Environmental Factors Considered

Subway Tunnels

-             Subway TST

-             Subway MSC

·             The TNS subway is the most direct and shortest link to the proposed entrances, i.e. minimise the extent of the construction works area and limit the works area to the section of Nathan Road that are mostly surrounded by hotels and commercial buildings provided with central air conditioning systems and do not rely upon openable windows for ventilation.

·             The subway tunnels which form of a large proportion of the project are to be constructed using tunneling by mining method.  The environmental benefits include:

-     minimal airborne noise and dust impacts on nearby sensitive receivers;

-    minimal impact on the traffic and pedestrians at street level during construction to reduce the chance noise generated from possible traffic back up.

·             The subway alignment shifts towards the east side of Nathan Road away from the row of OVTs on west footpath of Nathan Road.

Cut-and-Cover Components –

Satellite Concourse, Connection Chamber, Plant Basement and Emergency Exit

·             Above ground construction work are inevitable.  Nevertheless, they are limited as far as practicable to:

-     Satellite Concourse;

-     Plant Basement;

-     Connection Chamber; and

-     Emergency Exit Stair. 

 

Moreover, cut and cover method is adopted, i.e. majority of construction works would be carried out under road deck.  Dust and airborne noise emission during construction, would be screened off by the road deck from the nearby receivers.

Plant Basement and Entrance A1 Upgrade

·             The two-level plant basement located near Entrance A1 is compact to minimise environmental impacts during the construction phase.  Comparing to the single-level scheme, the works area would be largely reduced, the associated impacts, particularly construction noise and fugitive dust impacts are substantially reduced.

·             Relocation of the plant basement near Entrance A1 provides an opportunity to upgrade the entrance.  The old entrance is over 26 years old.  The new entrance with use of transparent glass would reduce bulk effect and be in compatible with the adjacent urban setting.  The new facilities for the entrance include a disabled lift serving the station, street level and Kowloon Park. The accessibility/connectivity of Kowloon Park, a recreational/ leisure resource in urban Hong Kong, is effectively enhanced with the Entrance A1 upgrade in place as it significantly improves the pedestrian and disabled access to the park from the station with insubstantial level of visual impact.

·             Ventilation at the plant basement utilises the existing exhaust shaft that could avoid environmental impacts arising from construction of a new vent shaft.

Emergency Exit

·             The emergency exits are a statutory requirement for the TNS scheme.  The emergency exits are located at the Satellite Concourse and at the end of Subway MSC.

·             The emergency exit at the Satellite Concourse is routed via the Tung Ying Building Redevelopment in a dedicated route to street level.

·             The emergency exit at Subway MSC is situated in the planter along the east footpath at Nathan Road.  The above ground structure is level with the existing planter and finished with materials similar to the adjacent planter to provide total integration.  Moreover it is well away from the OVT.  As such visual and landscape impacts are minimised.

 

2.6.2                    Following review of the scheme options, construction methods and environmental factors, the preferred scheme for the Tsim Sha Tsui Station Northern Subway consist of :

a)            A subway (Subway TST) from the north end of TST Station, running approximate 85m under Nathan Road to a Satellite Concourse;

b)            A satellite concourse (the Satellite Concourse) approximate 45m underneath Nathan Road, containing ticket gates (reversible type), ticket issuing machines (TIMs), self service points, help-lines, etc.  It has direct underground connections to the basements of the Miramar Hotel and of the development on the site of the former Tung Ying Building - these integrated entrances are designated Q2 and Q1 respectively.  A mezzanine level in the Satellite Concourse contains electrical and ventilation plantrooms for the subway;

c)            A subway (Subway MSC) from the north end of the Satellite Concourse, running approximate 80m under Nathan Road to the Miramar Shopping Centre (MSC), where an underground link connects to its basement.  This integrated entrance is designated Q3;

d)            An Emergency Exit situated in the east footpath and planter of Nathan Road, outside the Miramar Shopping Centre;

e)            The fresh, ventilation and smoke exhaust ducts for TNS are integrated with the Tung Ying Redevelopment and Hotel Miramar;

f)              A two-level plant basement (Plant Basement) located below and in front of Entrance A1 to house the displaced E&M equipment from the north end of TST Station; and

g)            Entrance A1 upgrade to replace the existing concrete structure with a new transparent box reconstructed on the same site with a improved access to the station with new disabled lift serving TST concourse level, street and Kowloon Park; and escalators serving street and the existing Entrance A1 Adit.

2.7                         Implementation and Planning of the Proposed Project

2.7.1                    The proposed works are scheduled to commence in June 2009 with duration of approximately 35 months. The entire project is scheduled to be completed in May 2012. The preliminary construction programme for the Project is shown in Table 2.2.

Table 2.2    Preliminary Construction Programme

Activity

Time period

Site clearance and set up

Jun 2009 to Jul 2009

Tree Protection

Jun 2009 to Jan 2012

Plant Basement and Entrance A1 construction

Jul 2009 to Dec 2010 and Nov 2010 to Nov 2011

Satellite Concourse and Entrances Q1 and Q2 construction

Nov 2009 to Jan 2012

Subway to TST Station

Mar 2011 to Dec 2011

Subway to Miramar Shopping Centre and Entrance Q3 construction

Feb 2011 to Dec 2011

Emergency Exit at Miramar Shopping Centre

Jul 2009 to Aug 2009, Nov 2011 to Feb 2012

TST Connection Chamber

Jul 2009 to Mar 2010

TST North End modification

Jun 2011 to Mar 2012

Landscaping works

Oct 2011 to Jan 2012

Site reinstatement works

Jan 2012 to May 2012

2.7.2                    The construction of the proposed Plant Basement and Satellite Concourse are divided into six stages to adopt temporary pedestrian flow and traffic diversion. The construction sequence of the Plant Basement and Satellite Concourse are shown in Figures 2.1 and 2.2 respectively.

2.7.3                    Based on the tentative construction programme, the Project will be carried out concurrently with the adjacent Tung Ying Building Redevelopment, which is under construction.  It is expected that the foundation and infrastructure works of the Tung Ying Building Redevelopment will be completed at the time of the commencement of this Project.  Consequently, cumulative environmental impacts from the Tung Ying Building Redevelopment are envisaged to be insignificant.

 


3.                              construction air quality impact

3.1                         Introduction

3.1.1                    This section presents air quality impact assessment during construction phases of the Tsim Sha Tsui Station Northern Subway (TNS) Project.  Representative Air Sensitive Receivers (ASRs) and the potential air quality impact on these receivers associated with the Project has been identified and assessed.  Appropriate mitigation measures would be proposed if necessary.

3.2                         Environmental Legislation, Standards and Guidelines

3.2.1                    The criteria for evaluating air quality impacts and the guidelines for air quality assessment are set out in Annex 4 and Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).

Air Quality Objective & EIAO-TM

3.2.2                    The Air Pollution Control Ordinance (APCO) provides the statutory authority for controlling air pollutants from a variety of sources.  The Hong Kong Air Quality Objectives (AQOs), which must be satisfied, stipulate the maximum allowable concentrations of certain pollutants over specific periods.  The relevant AQOs are listed in Table 3.1.

Table 3.1    Hong Kong Air Quality Objectives

 

Maximum Concentration (µg m-3) (1)

Pollutant

Averaging Time

 

1 hour (2)

8 hour (3)

24 hour (3)

Annual (4)

Total Suspended Particulates (TSP)

-

-

260

80

Respirable Suspended Particulates

(RSP) (5)

-

-

180

55

Sulphur Dioxide (SO2)

800

-

350

80

Nitrogen Dioxide (NO2)

300

-

150

80

Carbon Monoxide (CO)

30,000

10,000

-

-

Photochemical Oxidants

(as Ozone, O3) (6)

240

-

-

-

Notes:

(1)           Measured at 298 K and 101.325 kPa.

(2)           Not to be exceeded more than three times per year.

(3)           Not to be exceeded more than once per year.

(4)           Arithmetic mean.

(5)           Suspended particulates in air with a nominal aerodynamic diameter of 10 mm or smaller.

(6)           Photochemical oxidants are determined by measurement of ozone only.

 

3.2.3                    The EIAO-TM stipulates that the hourly TSP level should not exceed 500 mgm-3 (measured at 25°C and one atmosphere) for construction dust impact assessment.  Standard mitigation measures for construction sites are specified in the Air Pollution Control (Construction Dust) Regulations.

Air Pollution Control (Construction Dust) Regulation

3.2.4                    Notifiable and regulatory works are under the control of the Air Pollution Control (Construction Dust) Regulation.  Notifiable works are site formation, reclamation, demolition, foundation and superstructure construction for buildings and road construction.  Regulatory works are building renovation, road opening and resurfacing slope stabilisation, and other activities including stockpiling, dusty material handling, excavation, concrete production etc.  This Project is expected to include both notifiable and regulatory works.  Contractors and site agents are required to inform the Environmental Protection Department (EPD) on carrying out construction works and to adopt dust reduction measures to reduce dust emission to the acceptable level.

3.3                         Description of the Environment

3.3.1                    The Project is located in Tsim Sha Tsui district which is an urban area with mixture of commercial and residential developments.  The proposed works lie along Nathan Road from Cameron Road junction to Miramar Shopping Centre near Kimberley Road.  The proposed new plant basement is located under the existing Entrance A1 of the TST Station.

3.3.2                    There is no EPD air quality monitoring station at Tsim Sha Tsui.  The background pollutant values adopted for assessment are based on the EPD “Guideline on Assessing the ‘TOTAL’ Air Quality Impacts”.  In the categorisation of monitoring air quality data, Tsim Sha Tsui is categorised as urban development.  The latest five years (2002-2006) average monitoring data for urban development would be adopted as the background concentrations.  These urban monitoring stations considered in this assessment include: Central/Western, Kwun Tong and Sham Shui Po.  Table 3.2 summarizes the annual average TSP concentrations adopted as background concentrations for this air impact assessment.

 

Table 3.2    Annual Average TSP Concentration in the Latest Five Years (Year 2002 - 2006) for Urban Development

Pollutant

Annual Average Concentration in the Latest Five Years (mg m-3)

TSP

78

 

3.4                         Air Sensitive Receivers

3.4.1                    In accordance with the Annex 12 of the EIAO-TM, any domestic premises, hotel, hostel, hospital, clinic, nursery, school, educational institution, office, factory, shop, shopping centre, place of public worship, library, court of law, sports stadium or performing arts centre are considered to be an ASR.  Any other place with which, in terms of duration or number of people affected, has a similar sensitivity to the air pollutants as the aforelisted places are also be considered to be a sensitive receiver, for example, playground, sitting area of parks/promenade.

3.4.2                    No planned ASRs are located in vicinity of the Project.  The identified representative ASRs are listed in Table 3.3 and the corresponding locations are shown in Figure 3.1.

 

Table 3.3  Details of Representative Air Sensitive Receivers

ASR

Description

*Current Use

Distance from nearest emission sources (m)

A1

Parmanand House

Commercial

40

A2

Hai Phong Mansion

Residential and commercial

20

A3

Health Education Exhibition and Resource Centre

G/IC

35

A4

Health Education Exhibition and Resource Centre

G/IC

5

A5

Kowloon Mosque and Islamic Centre

Religionary

25

A6

Park Lane Shopper's Boulevard

Shop

20

A7

Park Lane Shopper's Boulevard

Shop

30

A8

Park Lane Shopper's Boulevard

Shop

25

A9

Park Lane Shopper's Boulevard

Shop

30

A10

Park Lane Shopper's Boulevard

Shop

55

A11

Cheong Hing Building

Residential and commercial

35

A12

Manson House

Service Apartment

25

A13

Majestic House

Residential and commercial

30

A14

Comfort Building

Residential and commercial

10

A15

Burlington Arcade

Residential and commercial

35

A16

Milton Mansion

Commercial

20

A17

Hotel Miramar

Hotel and Shop

10

A18

Miramar Shopping Centre

Commercial and Shop

5

A19

Antiquities & Monuments Office Antiquities Advisory Board Secretariat

G/IC

60

Note:    (*)    G/IC: Government, institution or community use. The permitted uses of the premise A16 are both residential and commercial

 

3.4.3                    As the construction activities are to be undertaken at and below ground level, the worst dust impact on the ASRs will be at the ground floor of the ASRs.  The height of 1.5m above ground, which is the breathing level of human, was adopted for the construction dust impact assessment.  In addition, 5m and 10m above local ground level were also selected to show the vertical variation of the pollutant concentrations.

3.5                         Identification of Pollutant Sources

3.5.1                    The plant basement and modification works at the existing entrance A1, connection chamber, satellite concourse, two subways and emergency exit are to be constructed at five works areas.  The construction period for the TNS Project is tentatively scheduled from June 2009 to early 2012.  According to the construction programme, the major dusty construction activities at the five works areas will not be overlapped.  However, the construction works at different areas are assumed to be undertaken simultaneously in the assessment as the worst case scenario.

3.5.2                    Cut-and-cover method would be adopted for the construction of the plant basement, connection chamber, satellite concourse and emergency exit.  Construction would be conducted initially above ground for installation of traffic deck.  Once the decking is completed, majority of the construction activities would be underground below the deck.  Aboveground construction works including excavation, material handling, loading and unloading of fill materials may pose potential dust impacts to ASRs in the vicinity of the site area of the proposed Project.

3.5.3                    For the construction of the subways connecting the new entrances and concourses, tunneling by mining method would be considered.  With the works conducted underground, no dust impact is expected.

3.5.4                    Based on the tentative construction programme, the proposed Project will be carried out concurrently with the Tung Ying Building Redevelopment adjacent to TNS Project Site, which is under construction.  However, it is expected that the foundation and infrastructure works of the Tung Ying Building Redevelopment will be complete at the time of the commencement of this Project i.e. June 2009  Cumulative environmental impacts from the Tung Ying Building Redevelopment are thus envisaged to be insignificant.

3.6                         Assessment Methodology

3.6.1                    The principal source of air pollution during the construction phase will be dust from the dusty activities as mentioned in Section 3.5.2.  The impact of fugitive dust sources on air quality depends upon the quantity as well as the drift potential of the dust particles emitted into the atmosphere.  Large dust particles (i.e. over 100 mm in diameter) will settle out near the source and particles that are between 30 and 100 mm in diameter are likely to undergo impeded settling.  The main dust impacts are likely to arise from particles less than 30 mm in diameter, which have a greater potential to disperse over greater distances.

3.6.2                    According to the USEPA AP-42, construction dust particles may be grouped into nine particle size classes.  Their size ranges are 0 - 1 mm, 1 - 2 mm, 2 - 2.5 mm, 2.5 - 3 mm, 3 - 4 mm, 4 - 5 mm, 5 - 6 mm, 6 - 10 mm and 10 - 30 mm, and the percentage of particles in each class was estimated to be 4%, 7%, 4%, 3%, 7%, 5%, 4%, 17% and 49%, respectively.

3.6.3                    The emission rates adopted in the TNS project assessment for different construction activities are based on the USEPA Compilation of Air Pollutant Emission Factors (AP-42), 5th edition.  The four major construction sources including:

·         Plant Basement;

·         TST Connection Chamber;

·         Satellite Concourse; and

·         Emergency Stair at MSC.

 

3.6.4                    Table 3.4 gives the relevant clauses for emission factors used in this assessment in AP-42.  Detailed calculation of emission rate is presented in Appendix 3.1.

Table 3.4  Emission Factors for Construction Activities

Emission Sources

Construction Activities

Emission Rate [2,3](g/m2/s)

Remark [1]

Plant Basement

Heavy Construction Activities

E = 7.394E-05

- 47.5%  work area

- 50% reduction by water suppression (watering twice a day)

- USEPA AP-42 5th ED., S.13.2.3.3

TST Connection Chamber

Heavy Construction Activities

E = 2.179E-05

- 14.0%  work area

- 50% reduction by water suppression (watering twice a day)

- USEPA AP-42 5th ED., S.13.2.3.3

Satellite Concourse

Heavy Construction Activities

E = 4.76354E-05

- 30.6%  work area

- 50% reduction by water suppression (watering twice a day)

- USEPA AP-42 5th ED., S.13.2.3.3

Emergency Stair at MSC

Heavy Construction Activities

E = 6.6005E-05

- 42.4%  work area

- 50% reduction by water suppression (watering twice a day)

- USEPA AP-42 5th ED., S.13.2.3.3

All Emission Sources

Wind Erosion

E = 2.6953E-06

- USEPA AP-42 5th ED., S.11.9, Table 11.9.4

                   Note:

-          [1] The percentage area under active operation has reconfirmed with Engineer.  The percentage active area is estimated based on the actual construction programme and the availability of plant equipment

-          [2] Only unit conversion has been conducted in the emission factors in accordance with AP-42.

-          [3] Assume 30 working days per month and 8 working hours per day.

 

3.6.5                    The Air Pollution Control (Construction Dust) Regulation specifies that dust suppression measures such as watering shall be applied for the construction site.  Dust emission from the site will be reduced by 50% if watering with complete coverage of active construction area twice a day.  This assumption was considered in the construction dust impact assessment.

3.6.6                    Fugitive Dust Model (FDM) (1993 version) was used to assess potential dust impact from the construction works.  The worst case meteorological data was used to predict the 1-hour and 24-hour average TSP concentrations at representative discrete ASRs close to the construction works.  As mentioned in Section 3.4.3, assessment level at 1.5m, 5m and 10m are included in the assessment.

3.6.7                    The meteorological data used in the model are:

·               Wind speed:                                   1 m/s

·               Wind direction:                                360 wind direction

·               Stability class:                                 D (daytime) & F (night time)

·               Surface roughness:                        1m

·               Mixing height:                                  500 m

3.7                         TSP Daily Concentration

3.7.1                    Daily TSP concentrations were calculated as follows:

Daily TSP concentration = (working hour)/24 ´ (1-hour average maximum TSP concentration during working hours) + (non-working hour)/24 ´ (1-hour average maximum TSP concentration during non-working hours) + Background.

3.7.2                    As mentioned in Section 3.3.2, the background TSP of 78 mg/m3 was adopted as an indication of the future TSP background concentration.

3.8                         Evaluation of Impacts

3.8.1                    The predicted maximum 1-hour and 24-hour average TSP during construction are shown in Tables 3.5 and 3.6, respectively.

 

Table 3.5 Predicted Maximum 1-hour Average TSP Concentrations

ASR

1.5m above ground

5m above ground

10m above ground

A1

186

147

95

A2

350

161

90

A3

203

152

93

A4

484

118

89

A5

247

160

93

A6

145

129

99

A7

182

137

94

A8

202

125

89

A9

108

105

96

A10

99

97

92

A11

206

153

93

A12

268

160

89

A13

224

156

91

A14

149

131

98

A15

163

136

97

A16

260

154

94

A17

365

158

94

A18

168

112

100

A19

103

100

93

Notes:  (1)   Background concentration is included.

(2)   1-hour TSP criterion of 500mg/m3 is stipulated in the EIAO-TM.

 

Table 3.6       Predicted Maximum 24-hour Average TSP Concentrations

ASR

1.5m above ground

5m above ground

10m above ground

A1

120

102

84

A2

179

107

82

A3

126

104

83

A4

223

92

82

A5

142

107

83

A6

105

97

85

A7

120

99

84

A8

126

94

82

A9

91

89

84

A10

87

86

83

A11

127

104

83

A12

150

107

82

A13

134

106

83

A14

106

98

85

A15

115

99

84

A16

153

105

84

A17

191

106

84

A18

112

92

86

A19

89

87

84

Notes:  (1)   Background concentration is included.

(2)   24-hour TSP criterion of 260mg/m3 is stipulated in the EIAO-TM.

 

3.8.2                    Based on the above prediction, no exceedance of 1-hour and 24-hour average TSP objective will occur at any representative ASR in the Study Area.  From the results, it is found that the maximum 1-hour and 24-hour average TSP concentrations will occur at 1.5m above ground (484mg/m3 and 223mg/m3, respectively). Contours of the maximum predicted 1-hour and 24-hour average TSP concentrations at 1.5m above ground are shown in Figures 3.2 and 3.3 respectively.

3.9                         Cumulative Impacts

3.9.1                    As mentioned in Section 3.5.4, it is expected that the foundation and infrastructure works of the Tung Ying Building Redevelopment would be completed at the time of the commencement of this Project. Another new commercial development (iSquare) is found at 63 Nathan Road (ex-Hyatt Regency Hong Kong Hotel at the junction of Peking Road and Nathan Road) which is about 95m to the south of the new plant basement works area of the Project.  The commercial development is scheduled to open in 2009 and all infrastructure construction works are expected to be completed by July 2009 when this Project start.  Thus, cumulative environmental impacts would not be expected.

3.10                     Mitigation of Adverse Environmental Impacts

3.10.1                To ensure compliance with the relevant standards, dust mitigation measures stipulated in the Air Pollution Control (Construction Dust) Regulation and good site practices shall be incorporated in the contract document to control potential dust emission from the site.  The major dust suppression measures include:

Ÿ          watering of active construction works area twice a day.

Ÿ          skip hoist for material transport shall be totally enclosed by impervious sheeting.

Ÿ          every vehicle shall be washed to remove any dusty materials from its body and wheels before leaving a construction site.

Ÿ          the area where vehicle washing takes place and the section of the road between the washing facilities and the exit point shall be paved with concrete, bituminous materials or hardcores.

Ÿ          where a site boundary adjoins a road, streets or other accessible to the public, hoarding of not less than 2.4m high from ground level shall be provided along the entire length except for a site entrance or exit.

Ÿ          every stack of more than 20 bags of cement shall be covered entirely by impervious sheeting places in an area sheltered on the top and the 3 sides.

Ÿ          all dusty materials shall be sprayed with water prior to any loading, unloading or transfer operation so as to maintain the dusty materials wet.

Ÿ          the height from which excavated materials are dropped shall be controlled to a minimum practical height to limit fugitive dust generation from unloading.

Ÿ          stockpile of excavated or dusty materials shall be covered entirely by clean impervious sheeting.

Ÿ          the load of dusty materials carried by vehicle leaving a construction site shall be covered entirely by clean impervious sheeting to ensure dust materials do not leak from the vehicle.

Ÿ          instigation of an environmental monitoring and auditing program to monitor the construction process in order to enforce controls and modify method of work if dusty conditions arise.

3.11                     Evaluation of Residual Impacts

3.11.1                With the implementation of dust suppression measures stipulated in Air Pollution control (Construction Dust) Regulation and watering of active construction works area twice a day during construction, no exceedance of AQO within the Study Area is predicted.  Therefore, no adverse residual dust impact is expected.

3.12                     Environmental Monitoring and Audit

3.12.1                With the implementation of the proposed dust suppression measures, good site practices and dust monitoring and audit programme, acceptable dust impact are expected at the ASRs.  Details of the monitoring requirements such as monitoring locations, frequency of baseline and impact monitoring are presented in the stand-alone EM&A Manual.


4.                              NOISE IMPACT

4.1                         Introduction

4.1.1                    This section presents the potential noise impacts arising from the proposed Project during construction and operation phases.  It is expected that construction and operation noise impact will arise from the proposed Project. Potential construction and operation noise impacts are evaluated in this study.

4.2                         Environmental Legislation, Policies, Plans, Standards and Criteria

General

4.2.1                    Noise impacts generated by the construction of this Project have been assessed in accordance with the criteria and methodology given in the Technical Memoranda (TMs) under the Noise Control Ordinance (NCO), and the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).

4.2.2                    The NCO and EIAO provide the statutory framework for noise control.  Applicable assessment procedures and standards are set out in three TMs listed below:

·               EIAO-TM

·               TM on Noise from Construction Work other than Percussive Piling (GW-TM)

·               TM on Noise from Construction Work in Designated Areas (DA-TM)

·               TM on Noise from Places other than Domestic Premises, Public Places or Construction Sites (IND-TM)

4.3                         Construction Noise – General Construction Works

4.3.1                    The NCO provides the statutory framework for noise control of construction work, other than percussive piling, using powered mechanical equipment (PME) between the hours of 1900 and 0700 hours or at any time on Sundays and general holiday (that is, restricted hours).  Noise control on construction activities taking place at other times is subject to the Criteria for Evaluating Noise Impact stated in Table 1B of Annex 5 in the EIAO-TM.  The noise limit is Leq (30 minutes) 75 dB(A) at the façades of dwellings and 70 dB(A) at the façade of schools (65 dB(A) during examinations).  The EIAO-TM construction noise criteria are summarised in Table 4.1.

4.3.2                     

Table 4.1    Daytime Construction Noise Criteria

Uses

Noise Level in Leq(30-minutes), dB(A)

Domestic premises

75

Educational Institution

70

Educational Institution (during examination)

65

 

Note: The above standards apply to uses which rely on opened windows for ventilation

 

4.3.3                    Between 1900 and 0700 hours and all day on Sundays and public holidays, activities involving the use of PME for the purpose of carrying out construction work is prohibited unless a construction noise permit (CNP) has been obtained.  A CNP may be granted provided that the Acceptable Noise Level (ANL) for the noise sensitive receivers can be complied with.  ANLs are assigned depending upon the area sensitive rating (ASR).  The corresponding ANLs for evening and night time periods are given in Table 4.2.

Table 4.2  Acceptable Noise Levels

Time Period

Acceptable Noise Level in Leq(5-minutes), dB(A)

ASR A

ASR B

ASR C

Evening (1900 to 2300 hours) (1)

60

65

70

Night (2300 to 0700 hours)

45

50

55

Note: (1) Includes Sundays and Public Holidays during daytime and evening

 

4.3.4                    Despite any description or assessment made in this EIA Report on construction noise aspects, there is no guarantee that a Construction Noise Permit (CNP) will be issued for the project construction.  The Noise Control Authority will consider a well-justified CNP application, once filed, for construction works within restricted hours as guided by the relevant Technical Memoranda issued under the Noise Control Ordinance.  The Noise Control Authority will take into account of contemporary conditions / situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP.  Nothing in this EIA Report shall bind the Noise Control Authority in making his decision.  Failure to comply with any such conditions will lead to cancellation of the CNP and prosecution action under the NCO.

4.3.5                    Under the DA-TM, the use of five types of Specified Powered Mechanical Equipment (SPME) and three types of Prescribed Construction Work (PCW) within a designated area during restricted hours would require a valid CNP.  The SPME includes hand-held breaker, bulldozer, concrete lorry mixer, dump truck and hand-held vibratory poker.  The PCW are:

·               erecting or dismantling of formwork or scaffolding

·               loading, unloading or handling of rubble, wooden boards, steel bars, wood or scaffolding material

·               hammering

4.3.6                    As defined in the Noise Control Designated Area Plan, all the works areas of the proposed Project are within the Designated Area.

4.3.7                    In general, it should not be presumed that a CNP will be granted for carrying out PCW within a designated area during the restricted hours.  The CNP may be granted for the execution of construction works during restricted hours involving the use of PME and/or SPME if the relevant Acceptable Noise Levels and criteria stipulated in the GW-TM and DA-TM can be met.

4.3.8                    According to the construction programme, most of the proposed construction works will be carried out during non-restricted hours, except for underground tunneling work and some construction activities in order to avoid local traffic impact.  In case of any construction activities during restricted hours, it is the Contractor’s responsibility to ensure compliance with the NCO and the relevant TMs.  The Contractor will be required to submit CNP application to the Noise Control Authority and abide by any conditions stated in the CNP, should one be issued.

4.4                         Fixed Noise in Operation Phase

4.4.1                    The major fixed plant noise sources identified are ventilation shafts of the proposed Project which would generate potential noise impact during operation. Fixed noise source such as ventilation noise is controlled by the NCO and IND-TM.  The appropriate Acceptable Noise Levels (ANL) generated by fixed plant at neighbouring NSRs are provided in the IND-TM.  The representative NSRs in the vicinity of ventilation shafts are located in urban area and are fronting the busy Nathan Road with an annual average daily traffic flow in excess of 30,000 in that road section according to Annual Traffic Census 2006 published by Transport Department.  Most of the NSRs will be directly affected by traffic noise. In this connection, the Area Sensitivity Rating (ASR) for these NSRs has been assumed as ‘C’.  The ANLs for an ASR of ‘C’ under the IND-TM are shown in Table 4.3.  The EIAO-TM recommends that noise standard for fixed noise source are (a) 5 dB(A) below the appropriate ANL, or (b) the prevailing background noise levels (For quiet areas with level 5 dB(A) below the ANL). The existing background noise level dominated by busy traffic along Nathan Road and community noise is expected to be higher than ANL – 5dB(A), therefore, the noise criteria of ANL – 5dB(A) i.e. 65/55 dB(A) (daytime and night-time) have been adopted for the assessment.

Table 4.3  Acceptable Noise Level for Fixed Plant Noise

Time Period

NCO criteria

Leq (30-min), dB(A)

EIAO-TM

Leq (30-min), dB(A)

ASR ‘C’

ASR ‘C’

Daytime and Evening (0700-2300 hours)

70

65

Night-time (2300-0700 hours)

60

55

 

4.4.2                    In any event, the Area Sensitivity Rating assumed in this EIA Report is for indicative assessment.  It should be noted that the fixed noise sources are controlled under section 13 of the NCO.  At the time of investigation, the Noise Control Authority shall determine noise impact from concerned fixed noise sources on the basis of prevailing legislation and practices being in force, and taking account of contemporary conditions/situations of adjoining land uses. Nothing in this EIA Report shall bind the Noise Control Authority in the context of law enforcement against all the fixed noise sources being assessed.

4.5                         Noise Sensitive Receivers

4.5.1                    In order to evaluate the construction and operation noise impacts from the proposed Project, representative existing noise sensitive receivers (NSRs) within the Study Area are identified for assessment.  Only the first layer of NSRs has been identified for assessment because it provides acoustic shielding to those receivers at further distance behind.  As the centrally air-conditioned buildings do not rely on opened windows for ventilation, the noise standard as stipulated in Tables 1A and 1B of Annex 5 of EIAO-TM would not be applicable, and hence these buildings have not been identified for noise impact assessment. Table 4.4 shows the representative NSRs for this noise impact assessment.

Table 4.4       Summary of Representative Noise Sensitive Receivers

NSR ID

Location

Permitted Land Use

Number of floors

Horizontal Separation from Closest Works Area Boundary (m)

N1

Hai Phong Mansion (53-55 Haiphong Road)

Residential and commercial

15 domestic floors above 3 commercial use floors

17

N2

Majestic House (80 Nathan Road)

Residential and commercial

13 domestic floors above 3 commercial use floors

30

N3

Comfort Building (86-88 Nathan Road)

Residential and commercial

11 domestic floors above 3 commercial use floors

9

N4

Burlington Arcade (90-94C Nathan Road)

Residential and commercial

14 domestic floors above 2 commercial use floors

29

*N5

Milton Mansion (96 Nathan Road)

Residential and commercial

12 floors

19

N6

Pacific Mansion (172-174 Nathan Road)

Residential and commercial

10 domestic floors above 4 commercial use floors

165

N7

Kowloon Mosque and Islamic Centre (105 Nathan Road)

Religionary

3

24 (East façade N7a),

7 (South façade N7b)

Remark: (*) Refer to Section 4.5.2 for the nature of this NSR

 

4.5.2                    According to the occupation permit of Milton Mansion (N5) issued by Building Department, the allowed uses are both commercial and residential.  Although it is identified as commercial use during the site survey, it is selected as a representative sensitive receiver in the assessment to study the impact level at this NSR should residential use be happened during the construction period of the Project.

4.5.3                    Two construction sites within the study area are found along Nathan Road i.e. 63 Nathan Road (iSquare) and 98 Nathan Road (Tung Ying Building Redevelopment). Both are commercial use.  The construction of the Urban Redevelopment Authority (URA) development at Mody Road (hotel and service apartment use) is almost complete.  According to the latest Outline Zoning Plan, most of the land uses within the study area are commercial use with a few G/IC, Open Space, Other Specified Uses and a few residential uses along Austin Road. No planned/committed noise sensitive receiver is identified within the study area during a site visit conducted on 9-Oct-2007.

4.5.4                    In the absence of the programme of planned/committed noise sensitive developments, construction and fixed noise impact assessment will only focus on existing NSRs.  The representative NSRs selected for assessments of construction noise and fixed noise have been shown in Figure 4.1.  The photographs of the representative NSRs are shown in Appendix 4.1.  Prior agreement with Environmental Protection Department has been sought on the selected representative assessment points for quantitative noise assessment.

4.6                         Assessment Methodology

Construction Noise

4.6.1                    The Project is scheduled to commence in June 2009 and to be completed in 2012.  According to the construction programme, there are seven major construction tasks. Some individual tasks have different stages.  Table 4.5 summarises the different tasks and the construction periods.  Most of the construction tasks are planned to be carried out during unrestricted hours.  In case of any construction activities during restricted hours, it is the Contractor’s responsibility to ensure compliance with the NCO and the relevant TMs.  The Contractor will be required to submit CNP application to the Noise Control Authority and abide by any conditions stated in the CNP, should one be issued.

Table 4.5       Construction Tasks Involved

Tasks

Description

*Construction Period

1

Plant Building

July 2009 to December 2010

2

Entrance A1

November 2010 to November 2011

3

TST Connection Chamber

July 2009 to March 2010

4

Satellite Concourse

November 2009 to January 2012

5

Subway to TST Station

March 2011 to December 2011

6

Subway to Miramar Shopping Centre

February 2011 to December 2011

7

Emergency Stair at Miramar Shopping Centre

July to August 2009 and November 2011 to February 2012

Note: (*) Construction period involving use of powered mechanical equipment only.

4.6.2                    The construction noise assessment has been carried out on a weekly basis from the commencement of the Project.  The construction tasks of the Project taking place concurrently within 300m of a given NSR are considered to contribute to the cumulative impact at that NSR.  Noise sources from the areas greater than this distance have been excluded from the assessment.

4.6.3                    In accordance with the EIAO, the methodology outlined in the GW-TM has been used for the assessment of construction noise (excluding percussive piling) and reference has been to the EIAO Guidance Note No.9/2004 on preparing the assessment. Sound Power Levels (SWLs) of the equipment were taken from Table 3 of this TM.  Where no SWL was supplied in the GW-TM, reference was made to BS 5228, previous similar studies or from measurements taken at other sites in Hong Kong.

4.6.4                    Schedule of powered mechanical equipment (PME) for the different construction tasks during normal daytime working hours is presented in Appendix 4.2.  The proposed plant inventory and utilization rate adopted in the assessment are considered practical and adequate in achieving the construction programme.  The plant inventory has been provided as an option and the contractor may propose alternative plant schedule should it be considered necessary and appropriate.

4.6.5                    The assessment is based on the cumulative SWL of PME likely to be used for each location, taking into account the construction period in the vicinity of the receiver location.  To predict the noise level, PME was divided into groups required for each discrete construction task.  The objective was to identify the worst case scenario representing those items of PME that would be in use concurrently at any given time.  The sound pressure level of each construction task was calculated, depending on the number of plant and distance from receivers.  The noise levels at NSRs were then predicted by adding up the SWLs of all concurrent construction tasks.

4.6.6                    Much of the excavation areas will be decked and this will shield the noise from construction plant operating below the deck.  For example, the rock drill used for excavation has noise emission but would be totally enclosed as it will be operated underground below the deck. Considerations will also be given to the location and the orientation of the temporary fixed noise sources required for the ventilation of the works area underneath the decked area. If exhaust above ground is required, it shall be located away from the existing residential building and facing towards the Kowloon Park (transient use). If required, silencer will be provided. It is anticipated that a metal sheet cover with surface density of 10kg/m2 or more covering the excavation areas would result in at least 20 dB(A) noise reduction.  Therefore, a noise reduction of 20 dB(A) was applied for the activities carried out underground. Schematic diagrams showing the typical site arrangement of underground works are shown in Figures 4.2 and 4.3.

4.6.7                    A positive 3 dB(A) façade correction was added to the predicted noise levels in order to account for the facade effect at each NSR.

Fixed Noise in Operation Phase

4.6.8                    In the proposed Project two ventilation shafts, one for exhaust extraction and one for smoke extraction, would be integrated with the Tung Ying Building Redevelopment and Hotel Miramar.

4.6.9                    Potential noise impacts arising from the operation of ventilation fans is expected at the sensitive receivers, and this fixed plant noise impact has been assessed in accordance with the IND-TM.

4.6.10                Table 4.6 summarises the ventilation shafts would be constructed for the proposed Project.

Table 4.6       Ventilation Shafts for the proposed Project

Location

Use

Tung Ying Building

*Exhaust/ Smoke extraction

Hotel Miramar

*Exhaust/ Smoke extraction

Note: (*) The use is either for exhaust or smoke extraction which is still not finalised in the design.

 

4.6.11                The ventilation fans for the smoke extraction and exhaust are all located underground inside the mezzanine level of the satellite concourse.

4.6.12                The ventilation fans of the smoke extraction shaft are operated for emergency only, however routine test of those ventilation fans would be carried out during day time. The potential impact from the concurrent operation of this shaft during day time period is assessed in the study.

4.6.13                The assessment assumes that all duty ventilation fans are operated for each ventilation shaft.  Screening corrections from other buildings / structures and directivity have also been excluded in the assessment.  All ventilation fans provided for each ventilation shaft will be installed with silencers.

4.6.14                In the absence of any detailed information and noise specification of the proposed fixed plant, the maximum permissible noise emission levels were determined for future detailed design of the fixed plant.

4.6.15                For the assessment of noise from the fixed plant, the maximum permissible sound power levels (Max SWLs) of the identified fixed noise sources were determined by adopting standard acoustics principles.  The following formula was used for calculating the Max SWLs of the fixed plant.

SPL = Max SWL – DC + FC

where

·               Sound Pressure Level, SPL in dB(A)

·               Maximum Permissible Sound Power Level, Max SWL in dB(A)

·               Distance Attenuation, DC in dB(A) = 20 log D + 8 [where D is the distance in metres]

·               Façade Correction, FC in dB(A) = 3 dB(A)

4.6.16                A positive 3 dB(A) was added to predicted noise levels at the NSRs due to the façade effect.

4.6.17                No corrections have been applied for tonality, intermittency or impulsiveness.  If the noise exhibits any of these characteristics during the operation of the plant, the noise limit should be reduced in accordance with the recommendation given in Section 3.3 of IND-TM.


4.7                         Identification of Environmental Impacts

Construction Phase

4.7.1                    The scope of this Project includes modification to the existing Entrance A1 and construction of the plant basement below; construction of a satellite concourse with integrated entrances to Tung Ying Building and Hotel Miramar; construction of subways connecting TST station and Miramar Shopping Centre with an integrated entrance and an emergency exit at Miramar Shopping Centre. Potential construction impacts of the Project may arise from the following activities:

·               Demolition of existing structure of Entrance A1 and construction of the plant basement below

·               Excavation at Entrance A1

·               Excavation at the existing Nathan Road southbound carriageway and footpath for satellite concourse, connection chamber and emergency exit

·               Construction of two subways by mined excavation

·               Road and pavement reinstatement and earthworks

4.7.2                    Driven piling and blast method would not be adopted for the construction works. The subway would be built using tunneling by mining method and no tunnel boring machine would be used.

4.7.3                    The Tung Ying Building Redevelopment located nearby the proposed works area of this Project would be carried out concurrently.  It is expected that the foundation and infrastructure works of the Tung Ying Building Redevelopment will be completed at the time of the commencement of this Project in June 2009.  Consequently, cumulative environmental impacts contributed from the Tung Ying Building Redevelopment are envisaged to be insignificant.

4.7.4                    Another new commercial development (iSquare) is found at 63 Nathan Road (ex-Hyatt Regency Hong Kong Hotel at the junction of Peking Road and Nathan Road) which is about 95m to the south of the new plant basement works area of the Project.  The commercial development is scheduled to open in 2009 and all infrastructure construction works are expected to be completed by July 2009 when this Project start.  Hence cumulative environmental impacts generated from this commercial development are not anticipated.

Operation Phase

4.7.5                    Ventilation noise affecting sensitive receivers in the study area may arise from the proposed ventilation shafts under the Project.

4.8                         Prediction and Evaluation of Environmental Impacts

Construction Phase

4.8.1                    For normal daytime working hours, exceedences of the construction noise criteria i.e. Leq (30 minutes) 75 dB(A) for residential uses are predicted at representative NSRs in the absence of mitigation measures.

4.8.2                    Details of construction noise calculations and results are presented in Appendix 4.3.  A summary of the unmitigated construction noise levels of the representative NSRs during normal daytime working hours within the construction period of the Project is listed in Table 4.7.

 

Table 4.7    Summary of Unmitigated Construction Noise Levels at Representative NSRs During Normal Daytime Working Hours

NSR ID

Predicted Noise Levels, dB(A)

Daytime Construction Noise Criteria, dB(A)

N1

56 – 87

75

N2

57 – 81

75

N3

60 - 89

75

N4

62 – 83

75

*N5

62 – 85

*75

N6

46 – 66

75

N7a

55 – 83

75

N7b

46 – 85

75

Note: (*) Noise criteria would be applied only if residential use exist in NSR N5 during the period of construction.

4.8.3