Central Reclamation, Phase III

Studies, Site Investigation, Design and Construction

 

 

Environmental Impact Assessment Report

Volume 1- Text

(July 2001)

CONTENTS

1.       Introduction

1.1     Background

1.2     History of Project including Previous Alternative Options Considered

1.3     Aims and Objectives

1.4     Study Area

1.5     Key Elements of the Project

1.6     Do Nothing Scenario

1.7     Report Construction

1.8     Built Heritage Impact Assessment

2.       Key issues

2.1     Introduction

2.2     Sensitive Receivers

2.3     Noise

2.4     Air Quality

2.5     Water Quality

2.6     Ecology

2.7     Waste Disposal

2.8     Landscape and Visual

3.       legislation and guidelines

3.1     EIA Ordinance Technical Memorandum

3.2     Noise

3.3     Construction Noise

3.4     Operational Noise Impacts

3.5     Air Quality

3.6     Water Quality

3.7     Ecology

3.8     Waste Disposal

3.9     Landscape/Visual

4.       Construction Sequence and interfaces

4.1     Construction Sequence – Issues and Constraints

4.2     Proposed Construction Sequence

4.3     Construction Programme

4.4     Project Interfaces

5.       Traffic Noise

5.2     Assessment Methodology

5.3     Prediction and Environmental Impacts

5.4     Mitigation of Adverse Environmental Impacts

5.5     Conclusion

6.       Fixed Noise Sources

6.1     Introduction

6.2     Operational Noise Receivers

6.3     Impacts

6.4     Conclusion

7.       Construction Noise

7.1     Introduction

7.2     Construction Noise Receivers

7.3     Construction Methodology

7.4     Assessment Methodology

7.5     Prediction and Evaluation of Environmental Impacts withoug Mitigation

7.6     Mitigation of Adverse Environmental Impacts and Evaluation of Residual Impacts

7.7     Conclusion

8.       operational AIR QUALITY

8.1     Introduction

8.2     Background Air Quality

8.3     Representative Sensitive Receivers for Operational Air Quality Impact

8.4     Assessment Methodology

8.5     Prediction and Evaluation of Environmental Impacts on CRIII ASRs

8.6     Mitigation Measures

8.7     Conclusion

9.       Construction Air Quality

9.1     Introduction

9.2     Construction Dust Generating Activities

9.3     Construction Dust Impact Assessment Methodology

9.4     Prediction and Evaluation of Environmental Impacts

9.5     Mitigation of Adverse Environmental Impacts

9.6     Potential Odour Impacts from Embayment

9.7     Asbestos

9.8     Conclusion

10.     Water Quality

10.1     Introduction

10.2     Sensitive Receivers

10.3     Existing Conditions

10.4     Baseline Water Quality Modelling

10.5     Sediment Conditions

10.6     Construction Phase Impact Assessment

10.7     Operation Phase Impact Assessment

10.8     Thermal Discharges

10.9     Biocide Discharges

10.10   Conclusions

11.     ECOLOGY

11.1     General

11.2     Habitat

11.3     Ecological Baseline

11.4     Ecological Importance

11.5     Impact Assessment

11.6     Impact Evaluation

11.7     Mitigation

11.8     Conclusion

12.     LAND CONTAMINATION

12.1     General

13.     WASTE DISPOSAL AND BIOGAS ASSESSMENT

13.1     Introduction

13.2     Existing Conditions

13.3     Future Conditions

13.4     Potential Sources of Impact

13.5     Marine Sediments

13.6     Construction and Demolition Waste

13.7     Chemical Waste

13.8     General Refuse

13.9     Mitigation Measures

13.10   Dredging Activities

13.11   Segregation of Wastes

13.12   Storage, Collection and Transport of Waste

13.13   Biogas Assessment

13.14   Conclusion

14.     Landscape and Visual Assessment

14.1     Introduction

14.2     Baseline Study – Description of the Environment within the CRIII Works Area

14.3     Planning and Development Control Framework

14.4     Landscape Impact Assessment

14.5     Visual Impact Assessment

14.6     Environmental Monitoring and Audit

14.7     Implementation and Funding

14.8     Conclusions and Recommendations

15.     MONITORING & AUDIT

15.1     Introduction

15.2     Dust

15.3     Noise

15.4     Water Quality

16.     SUMMARY

16.1     Potential Environmental Impacts and Key Issues

 


Appendices

Appendices are included in a separate volume - Volume 2

Appendix A        Project History

Appendix B        Review of Reclamation Methodology for CRIII Minimum Option

Appendix C        Detailed Construction Programme

Appendix D        Sample Output File for Road Traffic Noise Assessment / Confirmation Letter from Transport Department on CRIII Road Speeds

Appendix E        Powered Mechanical Equipment (PME) for Different Construction Tasks during Normal Daytime Working Hours

Appendix F        Detailed Calculations and Results of Cumulative Construction Noise Impacts during Normal Working Hours

Appendix G        Powered Mechanical Equipment (PME) for Different Construction Tasks during Restricted Working Hours

Appendix H        Detailed Calculations and Results of Cumulative Construction Noise Impacts during Restricted Working Hours

Appendix I          Sample CALINE Air Quality Model Output

Appendix J         Sample ISCST3 Air Quality Model Output

Appendix K        Calculation of Dust Emission Factors

Appendix L        Sample Computer Output from FDM used in Construction Air Quality Assessments

Appendix M        Dust Levels from Different Construction Scenarios (Unmitigated)

Appendix N        Dust Levels from Different Construction Scenarios (Mitigated)

Appendix O       Hydraulic and Water Quality Modelling Results

Appendix P        Information Abstracted from Previous Sediment Quality Report for the Project Site as applicable to the CRIII Minimum Option Layout

Appendix Q       Cumulative Water Quality Assessments for CRIII and WDII projects undertaken as part of the WDII EIA Study

Appendix R        SedPlume Modelling Scenarios and results from Previous Studies for the Project Site

Appendix S        EMSD Cooling Water Systems Data

Appendix T        Baseline Study - Description of the Environment

Appendix U        Planning and Development Control Framework

Appendix V        Landscape & Visual Impact Assessment for Redesign of the Airport Railway Extended Overrun Tunnel

Appendix W       Built Heritage Impact Assessment

 


TABLES

Table 2.1  :  Existing Air Sensitive Receivers (ASRs)

Table 2.2  :  Additional Future Air Sensitive Receivers (ASRs)

Table 3.1  :  Summary of Noise Standards

Table 3.2  :  Basic Noise Levels in dB(A) (BNLs)

Table 3.3  :  Area Sensitivity Ratings

Table 3.4  :  Basic Noise Levels in dB(A) (BNLs) for Designated Areas

Table 3.5  :  Environmental Standards for Fixed Noise Sources dB(A)

Table 3.6  :  Air Quality Objectives

Table 3.7  :  Standards for effluents discharged into the Marine Waters of Victoria Harbour Water Control Zone (All units in mg/l;  all figures are upper limits unless otherwise indicated)

Table 3.8  :  Standards for effluents discharged into the Inshore waters of Victoria Harbour Water Control Zone (All units in mg/L; all figures are upper limits unless otherwise indicated)

Table 3.9  :  Water Quality Objectives (WQOs) (All Phases) for Victoria Harbour

Table 3.10 :  Water Quality Objectives for Flushing Purposes

Table 3.11 :  Classification of Sediments by Metal Content (mg/kg dry weight) According to EPD TC No. 1-1-92

Table 3.12 : Sediment Quality Criteria for the Classification of Sediment  According to WBTC 3/2000

Table 4.1  : Summary of Construction Tasks and Stages for CRIII

Table 4.2 : Summary of Construction Programme

Table 4.3  :  Timings of Interfacing Projects

Table 5.1  :  Predicted Cumulative Traffic Noise Levels for Year 2027

Table 7.1: Summary of Unmitigated Construction Noise Levels Duirng Normal Working Hours

Table 7.2: Summary of Unmitigated Construction Noise Levels Duirng Restricted Hours

Table 7.3 : Summary of Mitigated Construction Noise Levels During Normal Working Hours

Table 7.4 :  Summary of Mitigated Construction Noise Levels During Restricted Hours

Table 8.1  :  Measured Annual Average Pollutant Levels µg/m3  at Central/Western Station (1999)

Table 8.2  : Emission Factors for Year 2011 for Different Vehicle Categories (EURO3)

Table 8.3  : Portal and Ventilation Building Emissions

Table 8.4  : Design of Ventilation Buildings

Table 8.5  :  Predicted Cumulative 1-hour Average NO2 , 24-hour Average NO2,  24-hour Average RSP and 1-hour Average CO concentrations at the CRIII Existing  and Future ASRs at 1.5m above ground level

Table 9.1  : Emission Factors for Construction Activities

Table 9.2  : Different Major Dust Generating Activities in the Worst Case Scenarios during the construction of CRIII

Table 9.3  : Predicted Cumulative 1-hour Average TSP Concentrations for Scenarios 1 to 8 (Unmitigated)

Table 9.4  : Predicted Cumulative 24-hour Average TSP Concentration for Scenarios 1 to 8 (Unmitigated)

Table 9.5  : Predicted Cumulative 1-hour Average TSP Concentration for Scenarios 1 to 8 (Mitigated)

Table 9.6  : Predicted Cumulative 24-hour Average TSP Concentration for Scenarios 1 to 8 (Mitigated)

Table 10.1 :  Water Sensitive Receivers (Sea Water Cooling Systems Intakes and Discharges)

Table 10.2 :  Summary Statistics of 1998 Water Quality – Victoria Harbour Central

Table 10.3 :  Summary Statistics of 1997 Water Quality – Victoria Harbour Central

Table 10.4 :  Summary Statistics of 1996 Water Quality – Victoria Harbour Central

Table 10.5 :  Summary Statistics of 1995 Water Quality – Victoria Harbour Central

Table 10.6 :  Target Accuracies Used for the Calibration of the Hydrodynamic Model

Table 10.7 :  Values of the water quality parameters in the calibration

Table 10.8 :  Timing of analysis tides within tidal sequences

Table 10.9 :  Discharges and pollutant loads of the outfalls and stormdrains assumed in the modelling, excluding pollutant sources near CRIII

Table 10.10 :  Discharges and Pollutant Loads of the Outfalls and Stormdrains near Central Assumed in the Modelling

Table 10.11 :  Water quality variable loads for the stormwater outfalls near Central

Table 10.12 :  Classification of Sediments by Metal Contents (mg/kg dry weight) (EPD Technical Circular No. (TC) No. 1-1-92)

Table 10.13 :  Physical parameter values used for the suspended sediment plume simulations

Table 10.14 :  Dredging and Filling Schedules

Table 10.15 :  Sediment release for the two scenarios

Table 10.16 : Simulated depth-averaged suspended mud concentrations given as elevation above ambient – Scenario 1

Table 10.17 : Simulated suspended mud concentrations given as elevation above ambient in the bed layer – Scenario 1

Table 10.18 : Simulated suspended mud concentrations given as elevation above ambient below mid-depth : Scenario 1

Table 10.19 : Simulated suspended mud concentrations given as elevation above ambient above mid-depth : Scenario 1

Table 10.20 : Simulated suspended mud concentrations given as elevation above ambient in the surface layer, Scenario 1

Table 10.21 : Simulated depth-averaged suspended mud concentrations given as elevation above ambient - Scenario 2

Table 10.22 : Simulated suspended mud concentrations given as elevation above ambient in the bed layer - Scenario 2

Table 10.23 : Simulated suspended mud concentrations given as elevation above ambient below mid-depth - Scenario 2

Table 10.24 : Simulated suspended mud concentrations given as elevation above ambient above mid-depth - Scenario 2

Table 10.25 : Simulated suspended mud concentrations given as elevation above ambient in the surface layer - Scenario 2

Table 10.26 :  Locations and discharges of the stormwater outfalls near Central during the construction phase

Table 10.27 :  Water quality variable loads for the stormwater outfalls near Central during the construction phase

Table 10.28 : Predicted SS Levels for Cumulative Scenario at the Seawater Intakes after the Implementation of Mitigation Measures

Table 10.29  : Comparison of discharge rates at Sections to the East & West  of the CRIII Area

Table 10.30 :  Locations and discharges of the stormwater outfalls near Central during the operational phase

Table 10.31 :  Water quality variable loads for the stormwater outfalls near Central during the operational phase

Table 11.1 : Organisms Potentially Present within the Study Area

Table 13.1 :  Heavy Metal Parameters at EPD Stations VS5 and VS6 in Central Victoria Harbour(mg/kg weight)

Table 14.1 : Landscape Impact Characteristic (Positive or Negative)

Table 14.2 :  Visual Impact Characteristic (Positive or Negative)

Table 14.3 : Residual Landscape Impacts from Reclamation

Table 14.4 :  Residual Landscape Impacts from Primary and Distributor Roads

Table 14.5 :  Residual Landscape Impacts from Central-Wan Chai Bypass Tunnel

Table 14.6 :  Residual Landscape Impacts from North Island Line Protection Works within CRIII

Table 14.7 :  Residual Landscape Impacts from CRIII (Schedule 3 Project)

Table 14.8 : Residual Visual Impacts from Designated Project 1 - Reclamation

Table 14.9 :  Residual Visual Impacts from Designated Project 2 – Primary and District Distributor Roads

Table 14.10 :  Residual Visual Impacts from Designated Project 3 – Central-Wan Chai Bypass Tunnel

Table 14.11 :  Residual Visual Impacts from Designated Project 4 - North Island Line Protection Works within CRIII

Table 14.12 : Residual Visual Impacts from CRIII (Schedule 3 Project)

Table 14.13 :  Landscape Framework - Implementation, Management and Maintenance Agents - Schedule of Responsibilities

Table 15.1 :  AL Levels for Total Suspended Particulate (TSP)

Table 15.2 :  AL Levels for Noise Measured at NSR during Construction

Table 16.1 :  Schedule of Impacts and Mitigation Measures

 

 

 

 


FIGURES

Figure 1.1        Extent of Full and Streamlined Reclamations 1.1.gif

Figure 1.2        Study Area and Proposed Layout 1.2.gif

Figure 2.1        Air / Noise Sensitive Receivers and Noise Prediction Points 2.1.gif

Figure 2.2        Water Quality Sensitive Receivers along the CRIII Waterfront 2.2.gif

Figure 2.3        Water Quality Sensitive Receivers outside CRIII site but considered in study 2.3.gif

Figure 2.4        Extent of Usage of Different Reclamatin Fill Materials 2.4.gif

Figure 4.1        Envisaged Construction Sequence – Stages 1 to 4 4.1.gif

Figure 4.2        Envisaged Construction Sequence – Stages 5 to 8 4.2.gif

Figure 5.1a      2027 AM Peak Hour Forecast Traffic Flow 5.1a.gif

Figure 5.1b      2027 AM Peak Hour Forecast Traffic Flow 5.1b.gif

Figure 5.1c      2027 AM Peak Hour Forecast Traffic Flow 5.1c.gif

Figure 5.1d      2027 AM Peak Hour Forecast Traffic Flow 5.1d.gif

Figure 5.2        Predicted Noise Levels at Sensitive Receivers 5.2.gif

Figure 6.1        Location of Fixed Noise Sources 6.1.gif

Figure 8.1        Location of Portals and Ventilation Buildings 8.1.gif

Figure 8.2a      Contours of Predicated Cumulative Maximum 1-Hour Average NO2 Concentrations in mg/m3 at 1.5m Above Ground Level 8.2a.gif

Figure 8.2b      Contours of Predicated Cumulative Maximum 1-Hour Average NO2 Concentrations in mg/m3 at 10m Above Ground Level 8.2b.gif

Figure 8.2c      Contours of Predicated Cumulative Maximum 1-Hour Average NO2 Concentrations in mg/m3 at 20m Above Ground Level 8.2c.gif

Figure 8.2d      Contours of Predicated Cumulative Maximum 1-Hour Average NO2 Concentrations in mg/m3 at 30m Above Ground Level 8.2d.gif

Figure 8.2e      Contours of Predicated Cumulative Maximum 1-Hour Average NO2 Concentrations in mg/m3 at 70m Above Ground Level 8.2e.gif

Figure 8.2f       Contours of Predicated Cumulative Maximum 1-Hour Average NO2 Concentrations in mg/m3 at 110m Above Ground Level 8.2f.gif

Figure 8.3        Contours of Predicated Cumulative Maximum 24-Hour Average NO2 Concentrations in mg/m3 at 1.5m Above Ground Level 8.3.gif

Figure 8.4        Contours of Predicated Cumulative Maximum 24-Hour Average RSP Concentrations in mg/m3 at 1.5m Above Ground Level 8.4.gif

Figure 8.5        Contours of Predicated Cumulative Maximum 1-Hour Average CO Concentrations in mg/m3 at 1.5m Above Ground Level 8.5.gif

Figure 9.1        Summary of Major Dust Generating Activities 9.1.gif

Figure 9.2        Contours of Cumulative Maximum 1-Hour Average TSP Concentrations in mg/m3 at 1.5m Above Ground Level (Mitigated) 9.2.gif

Figure 9.3        Contours of Cumulative Maximum 24-Hour Average TSP Concentrations in mg/m3 at 1.5m Above Ground Level (Mitigated) 9.3.gif

Figure 10.1a    Suspended Sediment Plume Scenario 1 sources in the Central area 10.1a.gif

Figure 10.1b    Suspended Sediment Plume Scenario 2 sources in the Central area 10.1b.gif

Figure 10.2      Suspended Sediment Plume Scenarios 1 and 2 sources for concurrent project 10.2.gif

Figure 10.3      Suspended Sediment Plume Scenario 1 sensitive receivers in the Central area 10.3.gif

Figure 10.4      Suspended Sediment Plume Scenario 2 sensitive receivers in the Central area 10.4.gif

Figure 10.5      Scenario 1 suspended mud concentrations at peak flood, dry season neap tide 10.5.gif

Figure 10.6      Scenario 1 suspended mud concentrations at peak ebb, dry season neap tide 10.6.gif

Figure 10.7      Scenario 1 suspended mud concentrations at the sensitive receivers, dry season neap tide 10.7.gif

Figure 10.8      Scenario 1 suspended mud concentrations at the sensitive receivers, dry season neap tide 10.8.gif

Figure 10.9      Scenario 1 suspended mud concentrations at the sensitive receivers, dry season neap tide 10.9.gif

Figure 10.10    Scenario 1 suspended mud concentrations at the sensitive receivers, dry season neap tide 10.10.gif

Figure 10.11    Scenario 1 suspended mud concentrations at the sensitive receivers, dry season neap tide 10.11.gif

Figure 10.12    Scenario 1 tide-and depth – averaged suspended mud concentrations, dry season neap tide 10.12.gif

Figure 10.13    Scenario 1 net deposition over one day, dry season neap tide 10.13.gif

Figure 10.14    Scenario 2 suspended mud concentrations at peak flood, wet season neap tide 10.14.gif

Figure 10.15    Scenario 2 suspended mud concentrations at peak ebb, wet season neap tide 10.15.gif

Figure 10.16    Scenario 2 suspended mud concentrations at the sensitive receivers, wet season neap tide 10.16.gif

Figure 10.17    Scenario 2 suspended mud concentrations at the sensitive receivers, wet season neap tide 10.17.gif

Figure 10.18    Scenario 2 suspended mud concentrations at the sensitive receivers, wet season neap tide 10.18.gif

Figure 10.19    Scenario 2 suspended mud concentrations at the sensitive receivers, wet season neap tide 10.19.gif

Figure 10.20    Scenario 2 suspended mud concentrations at the sensitive receivers, wet season neap tide 10.20.gif

Figure 10.21    Scenario 2 tide-and depth – averaged suspended mud concentrations, wet season neap tide 10.21.gif

Figure 10.22    Scenario 2 net deposition over one day, wet season neap tide 10.22.gif

Figure 10.23    Sensitive Receivers and Stormwater Outfalls – Initial Reclamation Layout 10.23.gif

Figure 10.24    Locations of Sections for Discharge Comparisons 10.24.gif

Figure 10.25    Sensitive Receivers and Stormwater Outfalls – Final Layout 10.25.gif

Figure 10.26    Locations of Cooling Water Pumping Station Outfalls at the Completion of CRIII Works 10.26.gif

Figure 14.1      Baseline Landscape and Visual Character Areas 14.1.gif

Figure 14.2      Baseline Visual Envelope and Photo View Point Locations 14.2.gif

Figure 14.3      Landscape and Visual Characteristics – Photograph Views A and B 14.3.gif

Figure 14.4      Landscape and Visual Characteristics – Photograph View C 14.4.gif

Figure 14.5      Landscape and Visual Characteristics – Photograph Views D and E 14.5.gif

Figure 14.6      Landscape and Visual Characteristics – Photograph View F 14.6.gif

Figure 14.7      Aerial View of the Study Area from the West (1997) Photograph View G 14.7.gif

Figure 14.8      Aerial View of the Study Area from the East (1997) Photograph View H 14.8.gif

Figure 14.9      Designated Project 1 - Reclamation Layout Plan and Section 14.9.gif

Figure 14.10    Designated Project 2 - Primary and District Distributor Roads Layout Plan and Section 14.10.gif

Figure 14.10a  Designated Project 2 - Primary and District Distributor Roads Landscape & Visual Mitigation Measures 14.10a.gif

FIGURES (CONT’D)

Figure 14.11    Designated Project 3 - Central Wan Chai Bypass Tunnel Layout Plan and Section 14.11.gif

Figure 14.12    Designated Project 4 - North Island Line Protection Works Layout Plan and Section 14.12.gif

Figure 14.13    Landscape Concept Plan 14.13.gif

Figure 14.14    Conceptual Landscape Master Plan 14.14.gif

Figure 14.15    Waterfront Promenade Typical Section 14.15.gif

Figure 14.16    Statue Square Open Space Corridor Typical Section 14.16.gif

Figure 14.17    Typical Streetscape Sections 14.17.gif

Figure 14.18    Section Through Reclamation Indicating Overall Location of Designated Projects and Implementation Programme 14.18.gif

Figure 14.19    Primary Visual Receivers and Proposed Development Heights 14.19.gif

Figure 14.20    View from Star Ferry, Kowloon Visual Impact of CRIII upon Existing and Committed Development and Ridge Line 14.20.gif

Figure 14.21    Photomontage View Point Locations (Refer to Figure 14.22 – 14.27) 14.21.gif

Figure 14.22a  Photomontage No. 1 – CRIII Viewed form the Peak Tower Existing View 14.22a.gif

Figure 14.22b  Photomontage No. 1 – CRIII Viewed from the Peak Tower View at Year 10 14.22b.gif

Figure 14.23a  Photomontage No. 2 – CRIII Viewed from North of “Star” Ferry Pier (Aerial View) Existing View 14.23a.gif

Figure 14.23b  Photomontage No. 2 – CRIII Viewed from North of “Star” Ferry Pier (Aerial View) View at Day One without Mitigation 14.23b.gif

Figure 14.23c  Photomontage No. 2 – CRIII Viewed from North of “Star” Ferry Pier (Aerial View) View at Year 10 14.23c.gif

Figure 14.24a  Photomontage No. 3 – CRIII Viewed from the 24th Floor of the Admiralty Centre Existing View 14.24a.gif

Figure 14.24b  Photomontage No. 3 – CRIII Viewed from the 24th Floor of the Admiralty Centre View at Day 1 without Mitigation 14.24b.gif

Figure 14.24c  Photomontage No. 3 – CRIII Viewed from the 24th Floor of the Admiralty Centre View at Year 10 14.24c.gif

Figure 14.25a  Photomontage No. 4 – CRIII Viewed from Expo Drive Existing View 14.25a.gif

Figure 14.25b  Photomontage No. 4 - CRIII Viewed from Expo Drive View at Day One without Mitigation 14.25b.gif

Figure 14.25c  Photomontage No. 4 – CRIII Viewed from Expo Drive View at Year 10 14.25c.gif

Figure 14.26a  Photomontage No. 5 – CRIII Viewed from North East of HKCEC (Aerial View) Existing View 14.26a.gif

Figure 14.26b  Photomontage No. 5 – CRIII Viewed from North East of HKCEC (Aerial View) View at Day One without Mitigation 14.26b.gif

Figure 14.26c  Photomontage No. 5 – CRIII Viewed from North East of HKCEC (Aerial View) View at Year 10 14.26c.gif

Figure 14.27a  Photomontage No. 6 – CRIII Viewed from “Star” Ferry Pier, TST Existing View 14.27a.gif

Figure 14.27b  Photomontage No. 6 – CRIII Viewed from “Star” Ferry Pier, TST View at Year 10 14.27b.gif

 

 

 


Abbreviations & Acronyms

ANL

Acceptable Noise Levels

APCO

Air Pollution Control Ordinance

AQOs

Air Quality Objectives

ASRs

Air Sensitive Receivers

ATRT

Advance Trunk Road Tunnel

BOD

Biological Oxygen Demand

CRI

Central Reclamation Phase I

CRIII

Central Reclamation Phase III

CRIII-FR

Central Reclamation Phase III, Full Reclamation

CRIII-SO

Central Reclamation Phase III, Streamlined Reclamation

CRIII-MO

Central Reclamation Phase III, Minimum Option

CRTN

Calculation of Road Traffic Noise

CWB

Central-Wan Chai Bypass

CWTC

Chemical Waste Treatment Centre

DO

Dissolved Oxygen

DP

Designated Project

DSD

Drainage Services Department

EIA

Environmental Impact Assessment

EIAO

Environmental Impact Assessment Ordinance

EIAOTM

Technical Memorandum on Environmental Impact Assessment Process

EM&A

Environmental Monitoring and Audit

EM&A

Environmental Monitoring and Audit

EOT

Hong Kong Station Extended Overrun Tunnel

EP

Environmental Permit

EPD

Environmental Protection Department

FDM

Fugitive Dust Model

FEIASO

Final EIA Report for the Streamlined Option

FMC

Fill Management Committee

GID

Green Island Development

GPO

General Post Office

HAB

Home Affairs Bureau

HKAPA

Hong Kong Academy for Performing Arts

IEC

Island East Corridor

IFC

International Finance Centre

ISCST3

Industrial Source Complex Short Term (Version 3)

LCSD

Leisure and Cultural Services Department

MTRC

Mass Transit Railway Corporation

NCO

Noise Control Ordinance

NH3

Ammonia

NIL

North Island Line

NO2

Nitrogen Dioxide

NSR

Noise Sensitive Receiver

PGGE

Principal Government Geotechnical Engineer

RSP

Respirable Suspended Particulates

SO2

Sulphur Dioxide

SS

Suspended Solids

SSDS

Strategic Sewage Disposal Scheme

SSSI

Site of Special Scientific Interest

TDD

Territory Development Department

TIA

Traffic Impact Assessment

TIN

Total Inorganic Nitrogen

TM

Technical Memorandum

TSP

Total Suspended Particulates

VSR

Visually Sensitive Receiver

WBTC

Works Branch Technical Circular

WCZs

Water Control Zones

WPCO

Water Pollution Control Ordinance

 


REFERENCES

1.   Green Island Development – Studies on Ecological, Water Quality and Marine Traffic Impacts. Agreement No CE 31/96. 3D TELEMAC (Dry Season Spring Tide) Flow Calibration Report. Babtie BMT (Hong Kong) Ltd, February 1998.

2.   Green Island Development – Studies on Ecological, Water Quality and Marine Traffic Impacts. Agreement No CE 31/96. 3D TELEMAC (Dry Season Neap Tide) Flow Calibration Report. Babtie BMT (Hong Kong) Ltd, February 1998.

3.   Green Island Development – Studies on Ecological, Water Quality and Marine Traffic Impacts. Agreement No CE 31/96. 3D TELEMAC (Wet Season Spring Tide) Flow Calibration Report. Babtie BMT (Hong Kong) Ltd, March 1998.

4.   Green Island Development – Studies on Ecological, Water Quality and Marine Traffic Impacts. Agreement No CE 31/96. 3D TELEMAC (Wet Season Neap Tide) Flow Calibration Report. Babtie BMT (Hong Kong) Ltd, March 1998.

5.   Green Island Development – Studies on Ecological, Water Quality and Marine Traffic Impacts. Agreement No CE 31/96. 3D Dry Season Water Quality Calibration Report. Babtie BMT Harris & Sutherland (Hong Kong) Ltd, May 1998.

6.   Green Island Development – Studies on Ecological, Water Quality and Marine Traffic Impacts. Agreement No CE 31/96. 3D Wet Season Water Quality Calibration Report. Babtie BMT Harris & Sutherland (Hong Kong) Ltd, June 1998.

1.             Central Reclamation Phase III, Marine Site Investigations, Swath Survey.  Contract No. HK 5/95.  Final Report.  Gammon Construction Ltd & Electronic and Geophysical Services Ltd, November 1995.

2.             Strategic Sewage Disposal Scheme Environmental Impact Assessment Study.  Agreement No. CE 52/95.  Technical Note 1; Wastewater Flows and Loads and Effluent Characteristics, Montgomery Watson, April 1997.

3.             ERL (Asia) Ltd, 1988, Deep Bay Integrated Environmental management, Vol 2, The Impacts of Development, August 1998.

4.             Zhao Huantung, 1983, Hydrological characteristics of the Zhujiang (Pearl) River Delta.  Tropical Oceanology Vol 2, No. 2, May 1983.

5.             HR Wallingford, 1988, Hydraulic and water quality studies in Victoria Harbour, Mathematical modelling report – calibration of seasonal water movement and water quality models, Report EX 1690, May 1988.

6.             HR Wallingford, 1993, Strategic Sewage Disposal Scheme, Hong Kong, Extended Seasonal Mathematical Model of Water Movement and Water Quality, Report EX 2864, August 1993.

7.             Huang Xinhe, 1988, Water quality of the Zhujiang River (Guanghou River reach) in the early 1980’s Pollution of the Urban Environment, Polmet 88, Edit P Hills et al.  Vincent.  Blue Copy Co Ltd. 1988.

8.             Wan Chai Development Phase II, Comprehensive Feasibility Study, Environmental Impact Assessment Report (June 2001).

 

 


1.                                          INTROduction

1.1                                      Background

1.1.1                                In March 1992 a report titled "Development Options for Central and Tamar Reclamation" was presented to the Development Progress Committee (DPC). This report was endorsed and included a number of recommendations, in particular that Central Reclamation Phase III (CRIII) would meet the requirement for an overrun tunnel extension for the airport railway. A preliminary Feasibility Study was subsequently commissioned in 1994 to define the precise scope of the CRIII works, identify land requirements, make cost estimates, develop an implementation programme and identify resource requirements. A Preliminary Environmental Review was undertaken which concluded that the envisaged construction sequence may result in adverse water quality impacts due to the creation of embayed bodies of water between different parts of the reclamation. Without the full implementation of the Strategic Sewage Disposal Scheme (SSDS) to collect and transfer sewage for treatment and disposal, discharge of sewage and other pollutants, there was the potential to cause significant water pollution in the embayed area to the east of the reclamation.

1.1.2                                In February 1995, Atkins China Ltd (formerly Atkins Haswell) was commissioned by the Government of Hong Kong, Territory Development Department (TDD), Hong Kong Island and Islands Development Office to undertake the studies, site investigation, design and construction for the Central Reclamation Phase III Project (Agreement No. CE 15/94).  The studies were subsequently reviewed due to the enactment of the "Protection of the Harbour Ordinance" (in June 1997), the consequences of which are described in Section 1.2 below.

1.2                                      History of Project including Previous Alternative Options Considered

1.2.1                                The following sub-sections describe the history of the CRIII project, for the various reclamation options considered, from the initiation of the project to present day requirements.  These sections should be read in conjunction with Figure 1.1 (a,b, c and d), which indicate the change in extent of the reclamation from the full reclamation option through to the current accepted minimum reclamation scheme.

1.2.2                                The Full Reclamation Option: In 1987 the Central and Wan Chai Reclamation Feasibility Study commenced in order to investigate a new reclamation along the foreshore of Central and Wan Chai.  This study concluded that a reclamation of 108 hectares could be constructed for the purpose of providing a new foreshore, a trunk road (linking the future Route 7 with the Island Eastern Corridor) and an extension to the existing Central Business District.

Subsequent to this study, a number of reclamation projects have already been completed.  These are namely:

·                Central Reclamation Phase I - At the site of the new Airport Railway Development and Outlying Island Ferry Piers;

·                Central Reclamation Phase II - At the site of the old HMS Tamar Basin; and

·                Wan Chai Reclamation Phase I - At the site of the new extension to the Hong Kong Convention and Exhibition Centre.

The two remaining reclamation projects are Central Reclamation Phase III and Wan Chai Development Phase II.  In 1994, a study into the feasibility of the CRIII commenced, which was referred to as the "Full Reclamation Option" (CRIII-FR) and  concluded that a reclamation of 32 hectares would be required for the necessary proposed infrastructure works.

1.2.3                                The Steamlined Reclamation Option: Following the enactment of the "Protection of the Harbour Ordinance" in June 1997, the Government carried out a critical review of the scope of the Central and Wan Chai Reclamation, including the Central Reclamation Phase III project, in order to formulate a scheme which would comply with the Ordinance and at the same time provide enough land to serve the long term needs of the territory. At the conclusion of the review, a Streamlined Option was proposed which comprised of the original scope of Central Reclamation Phase III but with a streamlined shoreline commensurate with meeting transport infrastructure requirements. This was referred to as the CRIII-SO and had a reclamation area of 31 hectares.

The Central District (Extension) Outline Zoning Plan for the CRIII-SO was gazetted under the Town Planning Ordinance (in May 1998) and received a number of objections. The proposals were also reviewed during a LegCo Motion Debate (in July 1998) with LegCo members objecting unanimously to the proposed reclamation. In response, the Government undertook a process of reviewing the reclamation in order to minimise its extent but at the same time still provide sufficient land to meet the transport infrastructure requirements.

1.2.4                                The Minimum Reclamation Option: The revised layout developed for Central Reclamation Phase III, referred to as the “Minimum Option”,(CRIII-MO) has involved significant changes to the CRIII-FR configuration in that the previous reclamation, proposed on the seaward side of the Central - Wan Chai Bypass, is omitted except for the promenade and the Central-Wan Chai Bypass and North Island Line alignments have been moved southwards. The revisions made resulted in a large reduction of reclamation area from 31 hectares to approximately 18 hectares. In January 1999, Atkins China Ltd was instructed to carry out an Engineering Study and Planning Review for the Minimum Option of Central Reclamation Phase III.  It is based on this CRIII-MO scheme that this EIA report has been produced.

1.2.5                                A history of the key dates and planning context of the CRIII project has also been provided in Appendix A for the readers information.  Furthermore, there are a number of EIA reports covering the study area, including the immediate environs, which are registered with EPD under the EIAO and can be examined should the reader wish. These are:

·                Central and Wanchai Reclamation Development - Central Reclamation Phase 1, Focussed EIA Study (EIA-025/BC)

·                Central and Wanchai Reclamation Development Focussed Study for the Proposed extension to the Hong Kong Convention and Exhibition Centre - Stage 2, Final Report Volume 2 - Environment (EIA-030/BC)

·                Central and Wanchai Reclamation Development - Central Reclamation Phase 2, Contract No. HK4/94 EIA Final Report Volume 1 and 2 (EIA-040/BC)

·                Strategic Sewage Disposal Scheme Stage 1 Principal Collection and Treatment System - Supplementary EIA (EIA-090/BC)

·                Strategic Sewage Disposal Scheme Stage 1 Principal Collection and Treatment System EIA Volume 1 and 2 - Appendices (EIA/092/BC)

1.3                                      Aims and Objectives

1.3.1                                Requirements for an EIA

1.3.1.1                The EIA undertaken for the CRIII-FR was submitted in February 1997, but the report was not registered in accordance with the Ordinance procedures. The Final EIA Report for the CRIII-SO, (FEIASO) was issued in January 1999. Although the CRIII-MO is likely to have less impact than the CRIII-FR or the CRIII-SO, it is necessary to undertake a full EIA and proceed through the full EIAO procedure to register the EIA Report and ultimately obtain an Environmental Permit.

1.3.2                                EIAO Designated Elements

1.3.2.1                Under the EIAO TM Schedule 3, Engineering Feasibility Studies with a Study Area >20 Ha require an EIA, but do not require Environmental Permits.  This condition applies to the CRIII - MO Feasibility Study.  In addition to having to comply with the requirements of the EIAO - TM, the CRIII - MO EIA Study is also required to comply with the Study Brief currently deposited in the EIAO Register.

1.3.2.2                Under the EIAO TM Schedule 2, the following elements require both an EIA and Environmental Permits prior to commencement of construction.

·                The reclamation (Clause C.1) - The layout of which is shown on Figure 14.9 (refer to Chapter 14).  The size of the reclamation is 18 ha.

·                Primary and Distributor Roads (Clause A.1) - The road network of which is shown on Figure 14.10 (refer to Chapter 14).

·                Central and Wanchai Bypass (CWB) (Clause A.7) - The extent of which is shown on Figure 14.11 (refer to Chapter 14).

·                The North Island Line (NIL) Protection Works within CRIII (Clause A.7)  (the NIL Protection Works belong to the Mass Transit Railway Corporation and it is proposed that their construction be entrusted to CRIII to enable them to be constructed along with the CRIII works) - The extent of which is shown on Figure 14.12 (refer to Chapter 14).

1.3.2.3                In the case of the latter two designated projects, the CRIII EIA only covers the construction phase of the sections of works which will be entrusted as part of the CRIII project.  The need to include the NIL Protection Works within CRIII is justified on the basis that failure to construct the works at the same time as the CRIII works would result in major disruption to newly completed roads and infrastructure constructed as part of the CRIII project.  The inclusion of the protection works within CRIII will, however, not pre-empt the NIL Alignment.  All other aspects of the operation and construction of CWB and NIL will be conducted by others.

1.3.2.4                The Hong Kong Station Extended Overrun Tunnels (EOT), the structure of which will be constructed as part of CRIII, are considered to be an integral part of the Lantau and Airport Railway (LAR) as the EOT are essentially for train reversal and safety operation of the LAR.  The EOT is an exempted project under the EIAO because the LAR is an exented project under the EIAO and the EOT can only be constructed after the CRIII project has been cleared to proceed.

1.3.3                                EIA Objectives

1.3.3.1                The objectives of the EIA are as follows:

·                to identify and describe the elements of the community and environment likely to cause adverse impacts on the proposed development and/or likely to be affected by the proposed development including both the natural and man-made environment;

·                to identify and quantify emission sources and determine the significance of impacts on sensitive receivers and potential affected uses;

·                to identify existing landscape features and visual quality in the study area so as to evaluate the landscape and visual impacts of the proposed development;

·                to identify and quantify the potential losses or damage to flora, fauna and natural habitats;

·                to propose the provision of infrastructure or mitigation measures so as to minimise pollution, environmental disturbances and nuisances arising from the proposed development;

·                to identify and establish methods, measures and standards for inclusion into the design, which are necessary to mitigate environmental impacts to acceptable levels;

·                to identify constraints associated with the mitigation measures recommended in the study;

·                to work out the optimum conceptual layout which, as far as is reasonably practical, mitigates environmental impacts in line with the planning requirements; and

·                to confirm the acceptability, in environmental terms, of the preferred development in line with the preferred development parameters.

1.3.3.2                This report describes the existing environment within the study area, including background water and sediment quality, water movement and circulation, air quality and noise conditions.  It provides an assessment of environmental impacts and cumulative effects, in sufficient detail to identify those issues of key concern arising from the construction and operation phases of the project, which require mitigation and monitoring and audit. The detailed design for CRIII has recently commenced and the EIA has been based on a nominated fixed design. The EIA is based on practical and cost‑effective mitigation measures, necessary to minimise potential adverse environmental impacts arising from the project.

1.3.3.3                Additionally, the EIA identifies any insurmountable residual (that is, after mitigation) environmental impacts, and outlines possible mitigation measures and environmental monitoring and audit (EM&A) procedures.

1.4                                      Study Area

1.4.1                                The study area encompasses the area of Victoria Harbour to the southeast of the new Outlying Islands Ferry Piers and north of Edinburgh Place and Lung Wui Road. The area extends eastward to Fenwick Pier Street and the Fleet Arcade, and includes the existing GPO, Star Ferry Piers, Queens Pier, City Hall, PLA Headquarters, Hong Kong Red Cross Headquarters building and the Tamar Site. For the purposes of the Environmental Assessment, the assessment area has been extended to include potential sensitive receivers immediately south of Connaught Road Central and Harcourt Road. The study area and proposed layout is shown in Figure 1.2. Elements within a 300m radius of the site are described later in this report.  This EIA also includes impacts from the Central-Wan Chai Bypass and Wan Chai Development Phase II projects to take account of cumulative impacts.

1.5                                      Key Elements of the Project

1.5.1                                The key elements of the project are described as follows:

·                reclamation and seawalls, roads and associated services, North Island Line Protection Works and Advance Trunk Road Tunnel (ATRT) for the CWB;

·                reprovisioning of Star Ferry Pier, public landing steps, wallah wallah moorings, and motor boat/launch operators' kiosks;

·                external cooling water systems which consist of the cooling water pumping shells for future developments, and the reprovisioning of existing cooling water pumping stations and associated pipework systems and E&M works;

·                reprovisioning of existing Leisure and Cultural Services Department (LCSD)'s facilities;

·                provision of a flood relief path, stormwater culvert extensions, upgrading of hinterland stormwater drainage resulting from the reclamation, demolition of the existing waterfront structures and necessary landscaping;

·                the Hong Kong Station Extended Overrun Tunnel (EOT) and associated ventilation structures entrusted for construction within the CRIII works;

·                reprovisioning of the Government Heliport at the Wan Chai PCWA and reprovisioning of the Wan Chai PCWA at Chai Wan Basin.

1.5.2                                Environmental Assessments for the works which will be undertaken distant from the main CRIII area i.e. the reprovided Government Heliport and PCWA are not required for the following reasons :

Government Heliport : Under Schedule 2, Section B.2, the reprovisioned heliport is more than 300 m from any existing or planned residential development.  The heliport is also planned to be relocated from the site during the WDII project so is only a temporary use.

PCWA :                         Under Schedule 2, Section B.4, the reprovisioned cargo area is less than 1,000 m in length and is greater than 50 m from existing or planned sensitive uses.  The area is also currently zoned as OU (Cargo Working Area) on the relevant OZP.

1.6                                      Do Nothing Scenario

1.6.1                                The key objectives of the CRIII are to provide land for the Central and Wanchai Bypass, the Hong Kong Station Extended Overrun Tunnel and the North Island Line Railway. Without reclamation, these strategic transport structures cannot be provided. Redesign, realignment and delays to strategic transport infrastructure would be inevitable.

1.6.2                                Also, the reclamation will be predominantly used for open space, with the opportunity to provide a high quality waterfront promenade.

1.7                                      Report Construction

1.7.1.1                This Environmental Impact Assessment (EIA) Report highlights and assesses key issues identified in accordance with the Technical Memorandum (TM) of the EIA Ordinance. It documents the key issues for the EIA, the methodologies and results of the EIA Study, the extent of environmental impacts, and the mitigation measures necessary to reduce such impacts to an acceptable level.  The following sub-sections describes in brief the layout and structure of this EIA Report.

1.7.1.2                Section 1 provides an introduction to the Project and Environmental Assessment Report.

1.7.1.3                Section 2 provides an overview of the key issues associated with the project.

1.7.1.4                Section 3 outlines the relevant legislation and guidelines that govern the various types of environmental impacts that can be expected from the CRIII project.

1.7.1.5                Section 4 describes the construction sequence and interfacing projects.

1.7.1.6                Section 5 describes the nature and extent of traffic noise impacts.

1.7.1.7                Section 6 describes the nature and extent of noise impacts from fixed noise sources.

1.7.1.8                Section 7 describes the nature and extent of construction noise impacts.

1.7.1.9                Section 8 describes the nature and extent of operational air quality impacts.

1.7.1.10            Section 9 describes the nature and extent of construction air quality impacts.

1.7.1.11            Section 10 describes the nature and extent of water quality impacts, with particular emphasis on marine water quality impacts of dredging.

1.7.1.12            Section 11 describes the potential ecological impacts of the project.

1.7.1.13            Section 12 describes the nature and extent of land contamination impacts for the project.

1.7.1.14            Section 13 describes the potential waste generation and disposal impacts for the project.

1.7.1.15            Section 14 summarises the landscape and visual assessment (undertaken as a separate study).

1.7.1.16            Section 15 provides an outline for an Environmental Monitoring and Audit (EM&A) programme for the project.

1.7.1.17            Section 16 summarises the report.

1.8                                      Built Heritage Impact Assessment

1.8.1                                The built heritage impact assessment of the CRIII project has been conduced separately.  The report on this assessment is included in Appendix W for reference.

 


2.                                          Key issues

2.1                                      Introduction

2.1.1                                The EIA study provides a review of the key aspects and activities arising from the proposed CRIII based on the latest engineering design proposal. The key issues and concerns considered are highlighted in this chapter and are discussed in more detail in subsequent chapters of the report.

2.2                                      Sensitive Receivers

2.2.1                                Noise

2.2.1.1                Based on the defined sensitive receivers under Section 3 of Annex 13 of the EIAO TM, there is a library (at the City Hall), staff quarters (Central Barracks), performing arts centre (HKAPA) and an amphitheatre (at the HKAPA).  With the exception of the amphitheatre, the other receivers do not rely on openable windows for ventilation, therefore the noise standards given in Table 1A, Annex 5 of the EIAOTM are used as reference guidelines in the assessments in Chapters 5 - 7 of this EIA Report.  The only potential noise sensitive receiver (NSR) is the HKAPA amphitheatre.  Section 3 of Annex 13 of the EIAO TM does not specifically define hotels as noise sensitive receivers.  However, a standard is provided in Annex 5 for hotels, but this would apply to hotels without a ventilation system.

2.2.1.2                Although the main part of the HKAPA building is centrally ventilated, the outside performance venue is considered a sensitive facility. It should be noted that this outside venue is only used very infrequently for performances. Also due to the nature of the venue, the performance area is set at the lowest level with tiered seating for the audience.  Above this seating and surrounding the venue are 2.75m high barriers to provide shielding from external noise sources.

2.2.1.3                The location of the HKAPA NSR and other noise prediction locations are indicated on Figure 2.1.

2.2.2                                Air

2.2.2.1                Commercial and office buildings and a number of hotels dominate the urban area surrounding the CRIII site. These buildings are centrally ventilated and air-conditioned but it is important that the additional CRIII road traffic does not generate air pollutant levels which will result in an exceedance of the Air Quality Objectives at the building air intake locations. In accordance with Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO TM) representative existing air sensitive receivers (ASRs) in the area are as listed in Table 2.1 and are shown in Figure 2.1.  The ASR reference numbers presented are consistent with those used for the WDII and CWB EIA Studies.

 

 

Table 2.1  :  Existing Air Sensitive Receivers (ASRs)

ASR

Description

ASR

Description

A6

Crocodile Building

A20

Central Barracks

A7

Hang Seng Bank Headquarters

A21

Central Barracks

A8

Exchange Square III

A22

Far East Financial Centre

A9

Exchange Square I & II

A23

Admiralty Centre

A10

Exchange Square I & II

A24

Harcourt Garden

A11

Jardine House

A25

Police Headquarters

A12

Jardine House

A26

HK Academy for Performing Arts

A13

Statue Square

A27

Arts Centre

A14

Hong Kong Club Building

A28

Citic Tower

A15

City Hall

A29

Servicemen's Guides Association

A16

City Hall

A30

HK Academy for Performing Arts

A17

Furama Hotel

A31

Shui On Centre

A18

Hutchison House

A33

Pedestrian Plaza

A19

Bank of America Tower

A34

HKCEC Extension

2.2.2.2                The General Post Office will be demolished and relocated to another site and will, therefore, not be considered as an ASR in this assessment.  The new development on this site is considered as a future ASR (ASR69) in paragraph 2.2.2.3 below.  The HK Red Cross Headquarters and City Hall will be redeveloped on the same or adjacent sites.

2.2.2.3                Additional future air sensitive receivers are also shown in Figure 2.1 and are listed in Table 2.2.  The ASR reference numbers presented are consistent with those used for the WDII and CWB EIA Studies.

Table 2.2  :  Additional Future Air Sensitive Receivers (ASRs)

ASR

Description

A67

Comprehensive Development Area Site

A68

Airport Railway Hong Kong Station

A69

Future Commercial Buildings and Landscaped Deck east of new Outlying Islands Ferry Piers (CDA site)

A70

Proposed Central Government Complex

A71

New G/IC site south and east of Citic Tower (to include the redeveloped HK Red Cross Headquarters)

A72

New G/IC site north of Citic Tower

A73

Waterfront related commercial and leisure uses

A74

Open space promenade along new reclamation edge

A75

Festival Market

A76

Waterfront related commercial and leisure uses

A77

Waterfront related commercial and leisure uses

A78

Grade A Office

2.2.3                                Water

2.2.3.1                There are no biological water sensitive receivers in the vicinity of the CRIII site and there are no particular areas of conservation value, ecological importance or mariculture activities in the vicinity. There are, however, several seawater pumping stations providing cooling water for air-conditioning systems in some of the nearby major buildings. There are also flushing water intakes further to the east of the site at Wanchai and North Point providing flushing water to the urban area. The water quality at the cooling water inlets does not come under any statutory environmental legislation but, in accordance with Annex 14 of the EIAO TM, water abstraction for cooling or flushing purposes is classified as a beneficial use that is sensitive to water pollution. The reclamation process should, therefore, not cause major deviations from the design intentions of the cooling water systems. The locations of the directly affected sea water intakes along the CRIII waterfront are shown in Figure 2.2. Other sea water intakes which are water quality sensitive receivers are: Kennedy Town, Wan Chai, Quarry Bay, Sai Wan Ho, Cha Kwo Ling, Yau Tong, Tai Wan, Yau Ma Tei and Cheung Sha Wan. These are illustrated in Figure 2.3 along with the position of the nearest WSD salt water intake located near the Wan Chai Public Cargo Working Area.

2.3                                      Noise

2.3.1                                Noise impacts will include construction noise impacts from dredging and reclamation formation and traffic noise impacts from CRIII roads. As there are limited numbers of receivers, it is likely that overall noise impacts will not be significant.

2.3.2                                The seawater pumping stations will be fixed noise sources. Given that they will be largely below ground and buffered from potential receivers by open space areas, they are not likely to create a highly significant impact. There may be a noise impact from the fans associated with the ventilation system for the CWB Tunnel which are proposed to be located to both the west and east of the CRIII area.

2.4                                      Air Quality

2.4.1                                Air quality impacts will include both construction dust impacts and operational road traffic exhaust related air pollution. The sources of the road traffic air emissions will be both from traffic travelling on proposed open road sections as well as from the ventilation shafts associated with the Central - Wanchai Bypass (CWB) Tunnel. There are a number of air sensitive receivers (refer to section 2.2.2), including hotels and office buildings in the study area which may be adversely affected by construction and operation air quality impacts.

2.5                                      Water Quality

2.5.1                                Introduction

Key issues associated with Water Quality may be considered under two categories :

·                Construction Stage Issues; and

·                Operation Stage Issues

These are described further in the following paragraphs.

2.5.2                                Construction Stage Issues

2.5.2.1                Marine Sediment Dredging and Disposal and Reclamation Filling

2.5.2.1.1                    As part of the Detailed Design for the Minimum Option, a review of reclamation methods and settlement issues was conducted.  This review considered both the environmental and engineering requirements associated with reclamation works.  The key findings of this review  are presented in Appendix B.  The review recommended that a fully dredged reclamation method should be adopted for the CRIII project. The Secretary of the Marine Fill Committee has confirmed that he has no objection to the proposal to remove 580,000m3 (i.e. total removal) of soft seabed marine mud and spoil from below the CRIII site.
2.5.2.1.2                    As part of the Detailed Design for the Minimum Option, and in accordance with the requirements of WBTC No. 4/98, a review of whether public fill material could be utilised in the reclamation platform construction was undertaken.  The findings of the review were submitted to the Public Fill Committee in early 2001 to request a partial exemption from the use of public fill for reclamation platform construction.  After a period of further review and discussion, the PFC confirmed that the CRIII reclamation platform could be formed using a combination of public fill in the form of surplus soft fill material from land formation projects and marine sand fill (largely placed below water level).
2.5.2.1.3                    The estimated volume of dredged marine sediment and fill materials (surplus soft fill, marine sand and rock fill) for the CRIII project are:

·                Dredged Material      :                580,000m3

·                Surplus Soft Fill        :                1,212,705m3

·                Marine Sand Fill        :                1,805,650m3

·                Rock Fill                   :                650,000 m3

The areas where marine sand and surplus soft fill materials will be used is shown in Figure 2.4.  The seawall foundations are currently envisaged to be constructed using rockfill materials.  A site specific plan for the reclamation area using public fill should be submitted to EPD  for final agreement before commencement of construction works.

2.5.2.1.4                    Based upon the currently proposed reclamation approach, it is estimated that dredging acti vities for the project would generate approximately 580,000 m3 of marine mud and spoil.  In accordance with EPD Technical Circular 1/1/92, it is estimated that 2% of the marine mud and spoil would be moderately contaminated (Class B) and 63% seriously contaminated (Class C), thus requiring special handling and disposal.
2.5.2.1.5                    The potential impacts to water quality from dredging and disposal of marine mud and bulk filling activities will vary according to the quantities and level of contamination, as well as the sensitive receivers at the dredging, filling and disposal sites.  These impacts may include :

·                suspension of solids in the water column during dredging and filling activities and marine sediment dumping activities, with the likely consequence of reduced DO levels and increased nutrient levels.

·                release of previously bound organic and inorganic constituents such as heavy metals, PAHs, PCBs, ammonia, sulphides and nutrients into the water column, either via suspension or by disturbance from turbulent flow or mud waves as a result of dredging activities, disposal of muds, or depositing fill materials;

·                release of contaminants from pore water and leachate forced out of sediments as a result of compaction or settlement during site formation;

·                release of the same contaminants due to leakages and spillages as a result of poor handling and overflow from barges during dredging and transport; and

2.5.2.1.6                    All of the above can result in deterioration in the receiving marine water quality and may have adverse effects on marine sensitive receivers.

2.5.2.2                Physical Effects of Dredging and Reclamation Filling

2.5.2.2.1                    Water quality impacts resulting from marine dredging and filling activities are directly related to resuspension of sediment that results in the increase in SS level in the water column.  Increased amounts of SS in the water column will increase the turbidity of sea water and will lead to a reduction of light penetration and an increase in heat retention.  The extent of physical impacts will depend on the amount of SS generated, the increase in temperature, and velocities of currents that disperse SS.
2.5.2.2.2                    Physical impacts to sensitive receivers such as cooling water intakes and pump inlets which occur because of increased sediment levels and siltation, include blockage of filters, fouling of pipes, and increased pump wear.  Increases in solid waste and sediment as a result of the dredging and filling programme and general construction activities can also result in an increase in temperature in the water column, which in turn can be detrimental to cooling water systems and intakes.
2.5.2.2.3                    These physical impacts can be minimised by careful dredging and filling operations , transportation and dumping of spoil.

2.5.2.3                Chemical and Biochemical Effects of Dredging

2.5.2.3.1                    High oxygen demands associated with the suspension of sediment may be exacerbated by elevated temperatures and the increased oxygen demand reduce light penetration may lead to diminished photosynthesis in the lower water column, and thus reducing the rate of oxygen produced.  Under extreme conditions this can lead to eutrophication, as algae blooms in the surface layer die exerting additional BOD in the lower water layer leading to anoxia.
2.5.2.3.2                    The extent of those chemical effects listed above, associated with the project, will depend on the contaminant levels of the marine sediments, nutrient content of the disturbed material, and the oxygen demand of the disposed material.
2.5.2.3.3                    Sediment consolidation rates and sediment entrainment from the natural seabed after disturbance, which effect the SS concentrations present, will depend largely on the construction method employed.
2.5.2.3.4                    The dredging of any sediment is likely to be undertaken via mechanical dredger with closed-form grabs, due to the sediment contamination.  The extent to which suspended sediment is dispersed during the construction period will also vary with tidal and storm conditions.

2.5.2.4                Impacts within the Reclamation Area

2.5.2.4.1                    During construction, a water body will be temporarily confined by Initial Reclamation Areas (refer to Chapter 4) and the existing Central Coastline, and may be impacted by the accumulation of polluted discharges, cooling water discharges and stormwater discharges.
2.5.2.4.2                    While this temporary water body is present, several cooling water inlets will draw water from inside it, and subsequently discharge back into it.  The initial reclamation may reduce the tidal flows and flushing within the study area.  This may cause these heated ‘thermal’ discharges from cooling water systems to remain localised and could raise the water temperature within this temporary water body.  Increases in ambient temperature may result in impacts upon water quality, including reductions in dissolved oxygen and under a worst case could result in anoxic conditions in the bottom layer of the water column.  In addition, temperature elevations could impact upon the efficiency of the cooling water systems in extracting water.
2.5.2.4.3                    Several stormwater culverts also discharge into the study area, and some of the dry weather flows contain organic material.  The pollution loading from existing storm drains and sewage outfalls has been estimated.  The temporary water body, when formed will receive all the existing discharges form stormwater culverts.  This may result in impacts associated with increases in oxygen demand such as reductions in dissolved oxygen concentrations.  Increases in nutrients may promote algal growth in the surface layer of the water column, leading to potential eutrophication.

2.5.3                                Operation Stage Issues

2.5.3.1                Water Movement

2.5.3.1.1                    The layout of the CRIII reclamation may have the potential to alter tidal flows and current speeds within the study area, and Victoria Harbour as a whole.  If the currents resulting from the new coastal configuration lead to accumulation of floating refuse and debris along the coastline, this could result in impacts upon cooling water intakes, including blocked filters and reduced efficacy.

2.5.3.2                Water Quality

2.5.3.2.1                    Any changes in tidal flow may result in impacts upon water quality.  In particular, if the new coastal configuration leads to the accumulation of floating refuse and debris, this will reduce the aesthetic water quality in the area.

2.5.3.3                Cooling Water Intakes and Discharges

2.5.3.3.1                    After the completion of CRIII, cooling water intakes will draw water from a more well mixed water body.  Cooling water will be discharged via outfalls located near stormwater culvert outfalls.  The main impact of the cooling water discharges is predicted to be localised in the water area between the reclaimed land and the island reclaimed during the HKCEC Extension Project prior to the completion of the planned Wan Chai Development Phase II project.

2.5.3.4                Floating Refuse and Debris

2.5.3.4.1                    Reduced tidal flushing in the embayment between CRIII and HKCEC extension reclamation prior to the completion of the planned Wan Chai Development Phase II project may lead to an increase in the amount of floating refuse collection and accumulation at the slack corner formed by the reclamation and the existing coastline.  This would lead to decreases in aesthetic quality in a highly public area, and may also result in a deterioration of water quality.  However, even if the levels increased as a result of decreased tidal flushing, it is considered that this would not result in insurmountable impacts.

2.6                                      Ecology

2.6.1                                The marine ecology of the study area is already severely degraded. No further significant impact on marine ecology is expected. The areas around the study area are primarily dense, urban and commercial in nature, so adverse impacts on the terrestrial ecology are not expected.

2.7                                      Waste Disposal

2.7.1                                The primary waste disposal issue will be associated with the disposal of contaminated sediments from dredging. The Sediment Quality Report for CRIII, prepared in 1996 indicated that seabed deposits are generally seriously contaminated. As indicated in paragraph 2.5.2.1.1, the recommended reclamation method will require 580,000 m3 of dredged material to be disposed of, of which it is estimated that 375,000 m3 will be contaminated. In view of the relatively small scale of the land-based construction works, other construction waste arisings are expected to be minimal.

2.7.2                                Biogas may be generated under anaerobic conditions from existing highly organic sediments and, if any of the sediments are left in place, there could be a potential risk of methane to subsequent developments on the reclamation.  Within the CRIII area, the sediments have a high organic content (as indicated in the Sediment Quality Study Final Report issued in April 1996 for the study area). With the full removal of marine mud and spoil, however, organic sediments will be removed, thus avoiding the risk of any impact from methane.

2.8                                      Landscape and Visual

2.8.1                                Introduction

2.8.1.1                Key landscape and visual issues associated with the CRIII development will be the landscape and visual impacts at the construction stage and operation stage and how these impacts can be successfully mitigated.  The following key impacts are predicted:

2.8.2                                Landscape Impacts

2.8.2.1                Construction Stage

The key landscape impacts at the construction stage will include:

·                impacts upon the existing landscape resource of Victoria Harbour through reclamation;

·                impacts upon the existing waterfront resource due to reclamation and use of waterfront for construction accesses and staging areas;

·                impacts upon streetscape and sitting out areas within the study area due to demolition and construction operations;

·                impacts upon landscape resources due to the loss of amenity facilities, including the “Star” Ferry Pier pedestrian plaza (which will be reprovisioned with a new pier prior to demolition), City Hall Memorial Garden and two temporary parks; and

·                impacts upon the landscape character of the waterfront. 

2.8.2.2                Operation Stage

The key landscape impacts at the operation stage will include:

·                impacts upon landscape resources due to the loss of 18Ha of Victoria Harbour through reclamation;

·                impacts upon landscape character and resources due to the implementation of the new Waterfront Park;

·                impacts upon landscape character and resources due to the implementation of the landscaping works within the Statue Square Open Space Corridor, Historic Corridor, Civil Corridor and Arts & Entertainment Corridor;

·                impacts upon landscape character and resources due to the implementation of new Streetscape landscaping works;

·                impacts upon landscape character and resources due to the implementation of Landscape Decks;

·                impacts upon landscape character and resources due to the implementation of Supplementary Landscape Spaces;

·                impacts upon landscape character and resources due to the upgrading of streetscape and sitting out areas within the study area; and

·                impacts upon landscape character and resources due to the implementation of roads and built development.

2.8.3                                Visual Impacts

2.8.3.1                Construction Stage

The key visual impacts at the construction stage will include:

·                views of barges carrying fill, floating cranes and dredging equipment;

·                loss of views to Victoria Harbour from Visually Sensitive Receivers (VSRs) located to the east, south and west of the study area;

·                loss of visual relationship between Central-Wan Chai waterfront and Victoria Harbour;

·                views of reclamation activity including pipe, cable, sewer and drainage works;

·                visual glare from welding and site illumination;

·                rotational site traffic, deliveries and cranes;

·                scaffolding and emergent structures; and

·                increased heavy vehicular traffic within the Central-Wan Chai Districts.

2.8.3.2                Operation Stage

The key visual impacts at the operation stage will include:

·                interference of, or obstruction to, views of Victoria Harbour from north and east facing VSRs within Jardine House and Exchange Square I and II;

·                interference of, or obstruction to, views of Victoria Harbour from north facing VSRs within the Hong Kong Club Building, Ritz Carlton Hotel and Furama Hotel;

·                interference of, or obstruction to, views of Victoria Harbour from north facing VSRs within the Far East Finance Centre and Admiralty Centre Towers I and II;

·                interference of views to Victoria Harbour from north facing VSRs within lower residential blocks of Central Barracks (e.g. Blake Block and Amethyst Block);

·                interference of or obstruction to views of Victoria Harbour from north facing VSRs within Citic Tower;

·                interference of, or obstruction to, views of Victoria Harbour from north west facing VSRs within the Hong Kong Police Headquarters at May House; and

·                new views over the proposed Marine Basin and Waterfront Promenade from north facing VSRs of the  Grand Hyatt Hotel, Shui On Centre, Telecom House, Hong Kong Arts Centre, and Harbour View International House.

 

 

 


3.                                          legislation and guidelines

3.1                                      EIA Ordinance Technical Memorandum

3.1.1                                CRIII is proceeding under the statutory provisions of the EIAO. It will be necessary to have a registered EIA Report, and obtain the necessary environmental permits before construction of the CRIII can commence.

3.2                                      Noise

3.2.1                                The statutory instrument for noise control is the Noise Control Ordinance (NCO) (Cap. 400) and its associated regulations and Technical Memoranda. Acceptable noise criteria for various sources are provided in the EIA-TM for various NSRs and are reproduced in Table 3.1.

Table 3.1  :  Summary of Noise Standards

 

Noise Source

Uses

 

 

Aircraft Noise (NEF)* Chek Lap Kok Airport

Helicopter Noise Lmax dB(A)

Road Traffic Noise L10
(1 hour) dB(A)

Rail Traffic Noise

Fixed Noise Source

 

 

All domestic premises including temporary housing accommodation

25

85

70

(a)  (See Note 3) The appropriate Acceptable Noise Levels shown in Table 3 of the Technical Memorandum for the Assessment of Noise from Places Other than Domestic Premises, Public Places or construction sites and

(b)  Lmax (2300 – 0700) = 85 dB(A)

(a)  5dB(A) below the appropriate Acceptable Noise Levels (ANLs) shown in Table 3 of the Technical Memorandum for the Assessment of noise from Places Other than Domestic Premises, Public Places or Construction Sites or

Hotels and hostels

25

85

70

 

(b)  the prevailing background noise level

Offices

30

90

70

 

 

Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required

25

85

65

 

(For quiet areas With level 5 dB(A) below the ANL)

Places of public worship and courts of law

25

85

65

 

 

Hospitals, clinics, convalescences and homes for the aged diagnostic rooms wards

25

85

55

 

 

Notes:  * -   NEF = Noise Exposure Forecast

             1)   The above standards apply to uses which rely on opened windows for ventilation

             2)   The above standards should be viewed as the maximum permissible noise levels assessed at 1m from the external façade.

             3)   Rail noise is under the control of the Noise Control Ordinance and shall comply with the acceptable Noise Levels laid down in the TM for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites.

3.3                                      Construction Noise

3.3.1                                The basic noise levels are dependent on the type of area containing the NSR and are detailed below in Tables 3.2 and 3.3.

Table 3.2  :  Basic Noise Levels in dB(A) (BNLs)

Time Period

ASR “A”

ASR “B”

ASR “C”

All days during the evening (19:00-23:00) and general holidays (and Sundays) during the days and evening (07:00-23:00)

60

65

70

All days during the night time (23:00-07:00)

45

50

55

Note:    ASR = Area Sensitivity Rating

Table 3.3  :  Area Sensitivity Ratings

Area Type

Not Affected

Indirectly Affected

Directly Affected

Rural area, including country parks or village type developments

A

B

B

Low density residential area consisting of low rise or isolated high rise development

A

B

C

Urban area

B

C

C

Area other than those above

B

B

C

3.3.2                                In addition to the above, there are controls on works in designated areas as defined in the Technical Memorandum on Noise from Construction Work in Designated Areas. This defines Specified Powered Mechanical Equipment (hand held breakers, bulldozer, concrete mixer lorry, dump truck, hand held concrete poker) and Prescribed Construction Work (erection or dismantling of form work or scaffolding, loading or handling of rubble, wooden boards, steel bars, wood or scaffolding material, and hammering).  The limits are given in Table 3.4.

Table 3.4  :  Basic Noise Levels in dB(A) (BNLs) for Designated Areas

Time Period

ASR “A”

ASR “B”

ASR “C”

All days during the evening (19:00-23:00) and general holidays (and Sundays) during the days and evening (07:00:23:00)

45

50

55

All days during the night time (23:00-07:00)

30

35

40

3.3.3                                The TM on EIAO provides evaluation criteria of 75 dB(A) at residential receivers, 70 dB(A) at schools/colleges and 65 dB(A) at schools/colleges during examination periods. These are daytime standards. It has become standard practice to include these limits in contract documentation.

3.4                                      Operational Noise Impacts

The Technical Memorandum for the Assessment of Noise from Places other then Domestic Premises, Public Places or Construction Sites, specifies the maximum permissible noise levels from fixed sources.  These are given in Table 3.5.

Table 3.5  :  Environmental Standards for Fixed Noise Sources dB(A)

Time Period

ASR A

ASR B

ASR C

Day (0700 – 1900)

60

65

70

Evening (1900 – 2300)

60

65

70

Night (2300 – 0700)

50

55

60

3.5                                      Air Quality

3.5.1                                The Air Pollution Control Ordinance (APCO) is the principal legislative tool to manage the air quality over Hong Kong.  Under the APCO, Air Quality Objectives (AQOs) for seven major air pollutants were established in 1987 and apply to the whole territory. In addition, a non-statutory 1-hour average criteria for Total Suspended Particulates (TSP) of 500 mgm-3 is applied to construction dust (as specified in the EIAO TM). Major component air pollutants from traffic and construction work include NO2 and particulates. The Hong Kong AQOs are given in Table 3.6.

Table 3.6  :  Air Quality Objectives


Concentration in mg/m3 (a)

Pollutant

Averaging Time

 

1 hour (b)

8 hours (c)

24 hours (c)

3 months (d)

1 year (d)

SO2

800

 

350

 

80

TSP

500 (g)

 

260

 

80

RSP (e)

 

 

180

 

55

NO2

300

 

150

 

80

CO

30,000

10,000

 

 

 

O3 (f)

240

 

 

 

 

Pb

 

 

 

1.5

 

Note :      (a)   Measured at 298K (25oC) and 101.325 kPa (one atmosphere).

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

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

              (d)   Arithmetic means.

              (e)   Respirable suspended particulates means suspended particulates in air with a nominal aerodynamic diameter of 10 micrometers or smaller.

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

              (g)   Limit for construction dust assessment given in the EIAO TM

3.6                                      Water Quality

3.6.1                                The Water Pollution Control Ordinance (WPCO)(Cap. 358) provides the statutory framework to set up Water Control Zones (WCZs) in which effluent discharges are regulated.  The study area is located within the catchment area for Victoria Harbour (Phase II) WCZ.

3.6.2                                The TM on Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters specifies effluent qualities that apply to different receiving water bodies under each WCZ.  All discharges are subject to licensing control except domestic sewage discharged to public foul sewers and unpolluted water into stormwater drains, river courses and water bodies.

3.6.3                                Effluents discharged into the waters of the Victoria Harbour WCZ from the study area during both construction and operational phases of the project should meet the effluent discharge standards as shown in Tables 3.7 and 3.8 and Water Quality Objectives as shown in Tables 3.9 and 3.10.  The EIAO TM (Annex 6) specifies the assessment criteria for evaluating water pollution.

Table 3.7  :  Standards for effluents discharged into the Marine Waters of Victoria Harbour Water Control Zone (All units in mg/l;  all figures are upper limits unless otherwise indicated)

Flow rate

(m3/day)

Determinant

£10

>10 and £200

>200 and £400

>400 and £600

>600 and £800

>800 and £1000

>1000 and £1500

>1500 and £2000

>2000 and £3000

>3000 and £4000

>4000 and £5000

>5000 and £6000

pH (pH units)

6-10

6-10

6-10

6-10

6-10

6-10

6-10

6-10

6-10

6-10

6-10

6-10

Temperature (co)

45

45

45

45

45

45

45

45

45

45

45

45

Colour

4

1

1

1

1

1

1

1

1

1

1

1

Suspended solids

700

600

600

500

375

300

200

150

100

75

60

40

BOD

700

600

600

500

375

300

200

150

100

75

60

40

COD

1500

1200

1200

1000

700

600

400

300

200

100

100

85

Oil & Grease

50

50

50

30

25

20

20

20

20

20

20

20

Iron

20

15

13

10

7.5

6

4

3

2

1.5

1.2

1

Boron

6

5

4

3.5

2.5

2

1.5

1

0.7

0.5

0.4

0.3

Barium

6

5

4

3.5

2.5

2

1.5

1

0.7

0.5

0.4

0.3

Mercury

0.1

0.1

0.05

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

Cadmium

0.1

0.1

0.05

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

Other toxic metals

2

1.5

1

0.8

0.6

0.5

0.32

0.24

0.16

0.12

0.1

0.1

Total toxic metals

4

3

2

1.6

1.2

1

0.64

0.48

0.32

0.24

0.2

0.14

Cyanide

1

0.5

0.5

0.5

0.4

0.3

0.2

0.1

0.1

0.08

0.06

0.04

Phenols

0.5

0.5

0.5

0.3

0.3

0.2

0.1

0.1

0.1

0.1

0.1

0.1

Sulphide

5

5

5

5

5

5

2.5

2.5

1.5

1

1

0.5

Total residual chlorine

1

1

1

1

1

1

1

1

1

1

1

1

Total nitrogen

100

100

100

100

100

100

100

100

100

100

100

50

Total phosphorus

10

10

10

10

10

10

10

10

10

10

10

5

Surfactants (total)

30

20

20

20

15

15

15

15

15

15

15

15

E.coli (count/100ml)

5000

5000

5000

5000

5000

5000

5000

5000

5000

5000

5000

5000

 

Table 3.8  :  Standards for effluents discharged into the Inshore waters of Victoria Harbour Water Control Zone (All units in mg/L; all figures are upper limits unless otherwise indicated)

Flow rate
(m3/day)
Determinant

£10

>10 and £200

>200 and £400

>400 and £600

>600 and £800

>800 and £1000

>1000 and £1500

>1500 and £2000

>2000 and £3000

>3000 and £4000

>4000 and £5000

>5000 and £6000

pH (pH units)

6-9

6-9

6-9

6-9

6-9

6-9

6-9

6-9

6-9

6-9

6-9

6-9

Temperature (co)

40

40

40

40

40

40

40

40

40

40

40

40

Colour

1

1

1

1

1

1

1

1

1

1

1

1

Suspended solids

50

30

30

30

30

30

30

30

30

30

30

30

BOD

50

20

20

20

20

20

20

20

20

20

20

20

COD

100

80

80

80

80

80

80

80

80

80

80

80

Oil & Grease

30

20

20

20

20

20

20

20

20

20

20

20

Iron

15

10

10

7

5

4

2.7

2

1.3

1

1.8

0.6

Boron

5

4

3

2.7

2

1.6

1.1

0.8

0.5

0.4

0.3

0.2

Barium

5

4

3

2.7

2

1.6

1.1

0.8

0.5

0.4

0.3

0.2

Mercury

0.1

0.1

0.05

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

Cadmium

0.1

0.1

0.05

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

0.001

Other toxic metals individually

1

1

0.8

0.7

0.5

0.4

0.25

0.2

0.15

0.1

0.1

0.1

Total toxic metals

2

2

1.6

1.4

1

0.8

0.5

0.4

0.3

0.2

0.14

0.1

Cyanide

0.2

0.1

0.1

0.1

0.1

0.1

0.05

0.05

0.03

0.02

0.02

0.01

Phenols

0.5

0.5

0.5

0.3

0.25

0.2

0.13

0.1

0.1

0.1

0.1

0.1

Sulphide

5

5

5

5

5

5

2.5

2.5

1.5

1

1

0.5

Total residual chlorine

1

1

1

1

1

1

1

1

1

1

1

1

Total nitrogen

100

100

100

100

100

100

80

80

50

50

50

50

Total phosphorus

10

10

10

10

10

10

8

8

5

5

5

5

Surfactants (total)

20

15

15

15

15

15

10

10

10

10

10

10

E.coli (count/100ml)

5000

5000

5000

5000

5000

5000

5000

5000

5000

5000

5000

5000

 

Table 3.9  :  Water Quality Objectives (WQOs) (All Phases) for Victoria Harbour

Water Quality Objective

Part or Parts of Zone

A.   AESTHETIC APPEARANCE

 

There should be no objectionable odours of discolouration of the water.

Whole zone

Tarry residues, floating wood, articles made of glass, plastic, rubber or of any other substances should be absent.

Whole zone

Mineral oil should not be visible on the surface.  Surfactants should not give rise to a lasting foam.

Whole zone

There should be no recognisable sewage-derived debris.

Whole zone

Floating, submerged and semi-submerged objects of a size likely to interfere with the free movement of vessels, or cause damage to vessels, should be absent.

Whole zone

The water should not contain substances which settle to form objectionable deposits.

Whole zone

B.   BACTERIA

 

The level of Escherichia coli should not exceed 1 000 per 100 mL, calculated as the geometric mean of the most recent 5 consecutive samples taken at intervals of between 7 and 21 days.

Inland waters

C.   COLOUR

 

Human activity should not cause the colour of water to exceed 50 Hazen units.

Inland waters

D.   DISSOLVED OXYGEN

 

a)    The level of dissolved oxygen should not fall below 4 mg per litre for 90% of the sampling occasions during the whole year; values should be calculated as the annual water column average (see Note).  In addition, the concentration of dissolved oxygen should not be less than 2 mg per litre within 2 m of the seabed for 90% of the sampling occasions during the whole year.

b)    The level of dissolved oxygen should not be less than 4 mg per litre.

Marine waters

 

 

 

Inland waters

E.   pH

 

a)    The pH of the water should be within the range of 6.5-8.5 units.  In addition, human activity should not cause the natural pH range to be extended by more than 0.2 unit.

Marine waters

b)    Human activity should not cause the pH of the water to exceed the range of 6.0-9.0 units.

Inland waters

F.   TEMPERATURE

 

Human activity should not cause the daily temperature range to change by more than 2.0 oC.

Whole zone

G.   SALINITY

 

Human activity should not cause the salinity level to change by more than 10%.

Whole zone

 


Table 3.9  :  Water Quality Objectives (WQOs) (All Phases) for Victoria Harbour (Cont’d)

Water Quality Objective

Part or Parts of Zone

H.     SUSPENDED SOLIDS

 

a)      Human activity should neither cause the suspended solids concentration to be raised more than 30% nor give rise to accumulation of suspended solids which may adversely affect aquatic communities.

Marine waters

b)      Human activity should not cause the annual median of suspended solids to exceed 25 mg per litre.

Inland waters

I.       AMMONIA

 

The un-ionized ammoniacal nitrogen level should not be more than 0.021 mg per litre, calculated as the annual average (arithmetic mean).

Whole zone

J.      NUTRIENTS

 

a)      Nutrients should not be present in quantities sufficient to cause excessive or nuisance growth of algae or other aquatic plants.

Marine waters

b)      Without limiting the generally of objective (a) above, the level of inorganic nitrogen should not exceed 0.4 mg per litre, expressed as annual water column average (see Note).

Marine waters

K.     5-DAY BIOCHEMICAL OXYGEN DEMAND

 

The 5-day biochemical oxygen demand should exceed 5 mg per litre.

Inland waters

L.      CHEMICAL OXYGEN DEMAND

 

The chemical oxygen demand should not exceed 30 mg per litre.

Inland waters

M.     TOXIC SUBSTANCES

 

a)      Toxic substances in the water should not attain such levels as to produce significant toxic, carcinogenic, mutagenic or teratogenic effects in humans, fish or any other aquatic organisms, with due regard to biologically cumulative effects in food chains and to interactions of toxic substances with each other.

Whole zone

b)      Human activity should not cause a risk to any beneficial use of the aquatic environment.

Whole zone

Note:   Expressed normally as the arithmetic mean of at least 3 measurements at 1 m below surface, mid depth and 1 m above the seabed.  However in water of a depth of 5 m or less the mean shall be that of 2 measurements (1m below surface and 1m above seabed), and in water of less than 3 m the 1 m below surface sample only shall apply.

 

 

Table 3.10 :  Water Quality Objectives for Flushing Purposes

 

Water Quality Objectives of sea water at intake point of salt water pumping stations for flushing

Colour (H.U.)

<20

Turbidity (N.T.U.)

<10

Threshold Odour No.

<100

Ammoniacal Nitrogen

<1

Suspended Solids

<10

Dissolved Oxygen

>2

Biochemical Oxygen Demand (5 days)

<10

Synthetic Detergents

<5

E. Coli / 100mL

<20,000

Chemical data expressed in mg/L

3.6.4                                There are no water quality objectives for the cooling water intakes specified by Government. Questionnaires were sent to request information regarding the operating condition and criteria of the existing cooling water systems within the CRIII area.  The replies received indicated that there was no particular absolute requirements for intake water quality. Hence, the sensitive receivers within the study area do not have specifications for the quality of the cooling water, although the threshold criteria of SS specified by users of several cooling water intakes (for example, Queen Mary Hospital Intake and Wah Fu Estate Intake) is 140 mgl-1. This level should only be treated as recommended threshold level and could vary according to the requirements of different cooling water users.

3.6.5                                The water quality objectives applicable to fish culture zones are that the SS level should not exceed 50 mg/l or a 100% elevation above the maximum value recorded over the past five years whichever is the lower.

3.7                                      Ecology

3.7.1                                The EIAO TM (Annex 8 and Annex 16) provides the criteria and guidelines for evaluating the ecological significance of a habitat or a site and the subsequent significance of the ecological impact on that site.

3.7.2                                The following are considered important habitats in Hong Kong:

·                mature native woodland greater than 1 ha;

·                undisturbed natural coastal area larger than 1 ha or longer than 500 m in linear measurement;

·                inter-tidal mudflats larger than 1 ha;

·                established mangrove stands of any size;

·                brackish or freshwater marshes larger than 0.5 ha;

·                established seagrass bed of any size;

·                natural stream courses or rivers longer than 1,000 m;

·                established coral communities of any size; and

·                other habitats found to have special conservation importance by documented scientific studies.

3.7.3                                Sites of habitat are evaluated on the basis of the following criteria:

·                naturalness (unmodified by man);

·                size;

·                diversity;

·                rarity (habitats and species);

·                re-creatability;

·                fragmentation;

·                ecological linkage;

·                potential value (through natural improvement or improved management);

·                nursery/breeding ground;

·                age; and

·                abundance/richness of wildlife.

3.7.4                                Ecological impacts are then evaluated on the basis of the following criteria:

·                habitat quality (evaluated on the basis of the criteria above);

·                presence of ecologically important species;

·                size/abundance of habitat or organisms;

·                duration of impact;

·                reversibility of impact; and

·                magnitude of impact.

3.7.5                                The Wild Animals Protection Ordinance (Cap.170) states that no person shall take, remove, injure, destroy, or wilfully disturb a nest or egg of any protected wild animal.

3.8                                      Waste Disposal

3.8.1                                The EIAO TM (Annex 7 and Annex 15) provides criteria and guidelines for evaluating waste management implications arising from the project.

3.8.2                                The following legislation is relevant to waste disposal in the study area:

·                Waste Disposal Ordinance (Cap 354);

·                Waste Disposal (Chemical Waste)(General) Regulation (Cap 354); and

·                Land Ordinance (Cap 28).

3.8.3                                The Waste Disposal Ordinance prohibits the illegal disposal of wastes, including trade waste, which is described as waste from any trade, manufacturer, business, or waste building as well as civil engineering materials. This definition is understood to include construction waste.

3.8.4                                The Waste Disposal (Chemical Waste) (General) Regulations define chemical wastes as substances or chemicals that occur in a form or quantity so as to cause a danger to public health or pollution to the environment.

3.8.5                                The Land Ordinance requires licenses be obtained by anyone transporting inert construction wastes to public fill (typically a reclamation area). Such inert material should be free from marine mud, household waste, plastic, metal, chemical or industrial wastes, and animal and vegetable matter.

3.8.6                                Marine Sediment Disposal

3.8.6.1                During reclamation works, dredging of harbour sediments will be required.  At the time of initial preparation of this report, sediments were classified according to their level of contamination by toxic metals as stipulated in the Environmental Protection Department Technical Circular No. 1-1-92, Classification of Dredged Sediments for Marine Disposal (refer also to paragraph 3.8.6.4 below). The contamination levels presented in the Technical Circular serve as criteria for determining the disposal requirements of the dredged sediments.  Definition of the classification is as detailed below and classification of sediments by metal content is shown in Table 3.11.

·                Class A: Uncontaminated material, for which no special dredging, transport or disposal methods are required beyond those which would normally be applied for the purpose of ensuring compliance with EPD's Water Quality Objectives, or for protection of sensitive receptors near the dredging or disposal areas.

·                Class B: Moderately contaminated material, which requires special care during dredging and transport, and which must be disposed of in a manner which minimises the loss of pollutants either into solution or by re-suspension.

·                Class C: Seriously contaminated material, which must be dredged and transported with great care, which cannot be dumped in the gazetted marine disposal grounds and which must be effectively isolated from the environment upon final disposal.

Table 3.11 :  Classification of Sediments by Metal Content (mg/kg dry weight) According to EPD TC No. 1-1-92

Class

Cd

Cr

Cu

Hg

Ni

Pb

Zn

A

0.0-0.9

0-49

0-54

0.0-0.7

0-34

0-64

0-140

B

1.0-1.4

50-79

55-64

0.8-0.9

35-39

65-74

150-190

C

1.5 or more

80 or more

65 or more

1.0 or more

40 or more

75 or more

200 or more

3.8.6.2                Following any dredging works, fill material will be deposited.  Since the proposed fill material to be used in the reclamation works i.e. marine sand will meet Hong Kong Environmental Protection Department (EPD) criteria for uncontaminated (Class A) material, impacts associated with fill operations will be limited to those associated with the release of suspended solids into the water column.

3.8.6.3                Disposal of dredged mud should be undertaken in accordance with the procedures outlined in the recently issued Works Branch Technical Circular Nos. 3/2000 and 12/2000.

3.8.6.4                A new sediment management framework, defined in WBTC 3/2000, has recently been introducted and provides new mandatory criteria for sediment classification and disposal.  The EIA Study Brief of the CRIII Comprehensive Feasibility Study was ,however, drafted prior to this new WBTC. In order to complete this CRIII EIA study under its current Brief, the EIA  has been completed on the basis that the older management framework would apply, particularly as the new framework had not been issued at the time of undertaking of the EIA Study work. However, a review of the Sediment Quality Study completed in 1996 was in progress at the time of writing the report, in order to respond to the new Sediment Quality Management Framework.  A limited assessment of contamination levels based upon the new classification criteria set out in WBTC 3/2000 has also be included in this EIA Report.  As such the criteria for sediment classificaiton set out in WBTC 3/2000 are provided in paragraph 3.8.6.5 below.

3.8.6.5                Under WBTC 3/2000 dredged sediments destined for marine disposal are classified according to their level of contamination by 13 contaminants as set out in Table 3.12.

Table 3.12 : Sediment Quality Criteria for the Classification of Sediment
According to WBTC 3/2000

 

Contaminants

LCEL

UCEL

Heavy Meat (mg/kg dry weight)

Cadmium (Cd)

1.5

4

Chromium (Cr)

80

160

Copper (Cu)

65

110

Mercury (Hg)

0.5

1

Nickel (Ni)

40

40

Lead (Pb)

75

110

Silver (Ag)

1

2

Zinc (Zn)

200

270

Metalloid (mg/kg dry weight)

Arsenic

12

42

Organic-PAHs (mg/kg dry weight)

PAHs (Low Molecular Weight)

550

3160

PAHs (High Molecular Weight)

1700

9600

Organic-non-PAHs (mg/kg dry weight)

Total PCBs

23

180

Organometallics (mg-TBT L-1 in interstital water)

Tributyltin

0.15

0.15

Source: Appendix A of WBTC 3/2000

Note:      LCEL - Lower Chemical Exceedance Level

                UCEL - Upper Chemical Exceedance Level

Sediments are categorised with reference to the LCEL and UCEL, as follows:

Category L      Sediment with all contaminant levels not exceeding the LCEL.  The material must be dredged, transported and disposed of in a manner that minimises the loss of contaminants either into solution or by suspension.

Category M     Sediment with any one or more contaminant levels exceeding the LCEL and none exceeding the UCEL.  The material must be dredged and transported with care, and must be effectively isolated from the environment upon final disposal unless appropriate biological tests demonstrate that the material will not adversely affect the marine environment.

Category H      Sediment with any one or more contaminant levels exceeding the UCEL.  The material must be dredged and transported with great care, and must be effectively isolated from the environment upon final disposal.

3.9                                      Landscape/Visual

3.9.1                                The following design standards and guidelines are applicable to landscape and visual impact assessment:

·                WBTC 25/92 Allocation of Space for Urban Trees;

·                WBTC 18/94 Management and Maintenance of both Natural Vegetation and Landscape Works;

·                Hong Kong Planning Standards and Guidelines;

·                WBTC 24/94 and PELBTC 3/94 “Tree Preservation”; and

·                HyDTC 6/98 - Visibility of Directional Signs.

 


4.                                          Construction Sequence and interfaces

4.1                                      Construction Sequence – Issues and Constraints

4.1.1                                The construction of the reclamation for Central Reclamation Phase III is constrained by a number of factors largely associated with maintaining existing facilities and operations prior to the completion of associated reprovisioned facilities.  Critical issues and constraints which affect the reclamation sequence are :

·                Private vessel and ferry operations from the existing Queen’s Pier, “Star” Ferry Piers and Tsim Sha Tsui East temporary ferry pontoon must be maintained until completion and opening of the reprovisioned ferry pier (Ferry Pier 8), public landing steps and refurbishment of the existing Ferry Pier 7 is completed.  In addition to maintaining safe marine access during this period, adequate land access will have to be maintained for pedestrians, public transport and private vehicles.  During earlier studies, it was established that the existing public landing steps to the immediate north of the Central Barracks at Tamar would need to be closed prior to commencing the CRIII construction works.  Marine Department have confirmed that these arrangements would still apply to the Minimum Option works with the exception that the westernmost set of landing steps within the existing seawall could be retained until the reprovisioned public landing steps are completed and opened for use.

·                The flows from stormwater drainage culverts F, J and K must be maintained at all times throughout the project works.  Temporary diversions can be utilised subject to satisfying the DSD that the flow capacity of the temporary diversions will not cause any increased risk of upstream flooding in the existing hinterland areas.

·                The operations of the existing cooling water facilities located along the Central waterfront affected by the works must be maintained until completion, commissioning and opening of the reprovisioned facilities.  This requirement involves maintaining intake and outfall flows, maintaining water quality at the intakes to acceptable levels and maintaining adequate maintenance access to the cooling water facilities.

·                The provision of sufficient land at as early a time as possible to permit construction of the following key infrastructure works :

-    The Central - Wanchai Bypass Tunnel; and

-    The Hong Kong Station Extended Overrun Tunnel.

·                The existing Government Heliport located to the north of Lung Wui Road is planned to be reprovisioned to the Wan Chai PCWA as soon as possible after the start of the CRIII works.  The timing of the relocation will be dependent upon the timing of relocation of the Wan Chai PCWA to Chai Wan Basin.

4.1.2                                Additional sewage generated by the development on CRIII will be directed to the CW3 Trunk Sewer and from there to the Wan Chai East screening plant and, until the SSDS is completed, discharged to the Harbour.  This method of dealing with the sewage has been accepted by DSD and EPD.  The additional sewage will be generated by the occupants of the new Central Government Complex, proposed commercial buildings and increases brought about by the redevelopment of some of the existing buildings. 

4.1.3                                With the exception of the new seawall formed using wave absorbing caisson units or cooling water pumping station structures incorporating wave absorbing chambers, a number of marine (coastal) facilities will be constructed during the CRIII works.  These facilities include :

· a military berth for the PLA; and

· reprovisioned ferry pier (Ferry Pier 8)and public landing steps.

4.1.4                                It is currently proposed that the PLA berth consist of a series of fender and bollard buttresses projected from the seawall caissons to create a berth for the berthing of vessels.  The fenders and bollard buttresses would essentially be an integral part of the seawall and would not affect the flow regime in the vicinity of the berth.  The final arrangement and detailing of the berth is, however, still subject to agreement with the PLA Garisson.

4.1.5                                The arrangement of the reprovisioned ferry pier (Ferry Pier 8) and public landing steps is still subject to finalisation within Government and completion of consultation with the ferry companies and other concerned parties.  The currently proposed arrangement is based upon constructing the ferry pier and public landing steps as piled deck structures at the north west corner of the CRIII area.  The structures proposed would not affect the flow regime in their vicinity.

4.2                                      Proposed Construction Sequence

4.2.1                                Taking account of the issues and constraints as outlined in section 4.1, a proposed construction sequence has been developed which is described below. The sequence is broadly similar to that proposed for the CRIII-FR, but adapted to take account of the reduction in reclamation area.  The sequence is illustrated in Figures 4.1 and 4.2.

4.3                                      Construction Programme

4.3.1                                A construction programme for Central Reclamation Phase III works has been prepared based upon the construction sequence illustrated in Figures 4.1 and 4.2.   The construction tasks for each contraction stage shown on these figures are provided in Table 4.1.   The construction programme is presented in a summary form for the EIA in Table 4.2. A detailed programme is also included in Appendix C.

At the completion of the CRIII works i.e. March 2007, based upon the current construction programme, land would be available for commencement of development of the promenade, open space areas and landscaped decks within future developments.  Advancement of certain works may be possible and will be considered during the detailed design phase of the project.

Table 4.1  : Summary of Construction Tasks and Stages for CRIII

Stage

Construction Period

Site Area

Main Construction Elements

1

End Aug 2002 to End March 2003

Initial Reclamation Area West

·         Dredging

·         Seawall Construction

·         Sand Filling

·         Civil Works for Cooling Water Pumping Stations

·         Piling for Ferry Pier 8

 

 

Hinterland Areas

·         Public Transport Facilities Behind Piers 4 - 6

·         Piling for EOT Vent Building

2

Start April 2003 to End Nov 2003

Initial Reclamation Area West

·         Sand Filling and Vibrocompaction

·         Civil Works for Cooling Water Pumping Stations

·         Superstructure for Ferry Pier 8

·         Piling for Public Landing Steps (Stage 1)

·         Superstructure for Public Landing Steps (Stage 1)

 

 

Initial Reclamation Area East

·         Dredging

·         Temporary Diversion of Culvert J

 

 

Hinterland Areas

·         Public Transport Facilities Behind Piers 6 - 7

·         Sheet Piling for EOT Vent Building

·         Superstructure for EOT Vent Building

·         NIL Protection Works, Stages 1& 2

3

Start Dec 2003 to End July 2004

Initial Reclamation Area West

·         Pipework for Cooling Water Pumping Stations

·         E&M and Finishing Works for Cooling Water Pumping Stations

·         Substations for Cooling Water Systems


Table 4.1 : Summary of Construction Tasks and Stages for CRIII (Cont'd)

Stage

Construction Period

Site Area

Main Construction Elements

3

 

Initial Reclamation Area East

·         Seawall Construction

·         Sand Filling and Vibrocompaction

·         Civil Works for Cooling Water Pumping Stations

·         Pipework for Cooling Water Pumping Stations

·         Substations for Cooling Water Systems

·         E&M and Finishing Works for Cooling Water Pumping Stations

·         Culvert J Construction

·         Central-Wan Chai Bypass Construction

·         NIL Protection Works, Stage 3

 

 

Hinterland Areas

·         EOT Vent Building Completion

·         NIL Protection Works, Stages 1 & 2

·         Drainage Improvement Works at Connaught Place

4

August 2004

Initial Reclamation Area East

·         Central-Wan Chai Bypass Construction

 

 

Final Reclamation Area West

·         Demolition of Piers

 

 

Hinterland Areas

·         Piling for EOT Vent Shafts

·         Drainage Improvement Works at Connaught Place

5

Start Sept 2004 to End April 2005

Initial Reclamation Area East

·         Central-Wan Chai Bypass Construction

 

 

Final Reclamation Area West

·         Dredging

·         Seawall Construction

·         Sand Filling

·         Surplus Soft Filling

·         Vibrocompaction

·         Temporary Diversion of Culvert F

·         Civil Works for Cooling Water Pumping Stations

·         Sheet Piling for EOT


Table 4.1 : Summary of Construction Tasks and Stages for CRIII (Cont'd)

Stage

Construction Period

Site Area

Main Construction Elements

 

 

Final Reclamation Area East

·         Dredging

·         Seawall Construction

 

 

Hinterland Areas

·         EOT Vent Shaft Construction

·         Drainage Improvement Works at Connaught Place

6

Start May 2005 to End Dec 2005

Final Reclamation Area West

·         Surplus Soft Filling and Vibrocompaction

·         Temporary Diversion of Culvert F

·         Foundations for Culvert F

·         Central Wan-Chai Bypass Construction

·         Sheet Piling for EOT

·         EOT Tunnel Construction

·         Piling and Superstructure for Public Landing Steps (Stage 2)

·         PLA Berth Construction

 

 

Final Reclamation Area East

·         Sand Filling and Vibrocompaction

·         Civil Works for Cooling Water Pumping Stations

·         Culvert K Construction

·         NIL Protection Works, Stage 4

·         Central-Wan Chai Bypass Construction

·         Road P2 Underpass

7

Start Jan 2006 to End Oct 2006

Final Reclamation Area West

·         Culvert F Construction

·         Central-Wan Chai Bypass Construction

·         EOT Tunnel Construction

·         Foundations to Man Yiu Street Footbridge

 

 

Final Reclamation Area East

·         Central-Wan Chai Bypass Construction

·         Road P2 Underpass

 

 

All Areas

·         Drainage & Utility Works

·         At Grade Roads & Landscaping (Except Roads D5, D6 & P1)


Table 4.1 : Summary of Construction Tasks and Stages for CRIII (Cont'd)

Stage

Construction Period

Site Area

Main Construction Elements

8

Start Nov 2006 to End Mar 2007

Final Reclamation Area West

·         Man Yiu Street Footbridge Construction

·         Drainage & Utilities to Roads D5, D6 & P1

·         PTI Construction

·         At Grade Roads & Landscaping to Roads D5, D6 & P1

Note:

1.   Seawall Construction includes completion of seawall foundations using rockfill materials.

2.   Sand Filling relates to bulk reclamation filling to above water level.

 

Table 4.2 : Summary of Construction Programme


Project Interfaces

4.3.2                                A number of current and proposed projects have been identified which will have an interface with the Central Reclamation Phase III project.  These projects are listed below and the construction and programme interface issues associated with them are described in this chapter.  The information presented in this chapter, particularly related to programme interface issues, is based upon the best information currently available and will be subject to change as further  details particularly of proposed projects are developed further.

4.3.3                                Projects which interface with the Central Reclamation Phase III project are:

·                Central – Wan Chai Bypass Project;

-    The structural works for the Central – Wan Chai Bypass tunnel located within the CRIII site will be constructed as entrusted works to the CRIII project, no programme interface issues are present. Potential impacts from the construction of the tunnel structural works are included in this EIA assessment.

·           Central Government Complex Project;

-    The programme for construction of the Central Government Complex is not fixed as advised by the Architectural Services Department.  In addition, there are no construction details available for this project to enable cumulative impacts, if any, to be incorporated into this EIA Study.

·                Redevelopment of Police Headquarters (Phase III) Project;

-    The Police Headquarters redevelopment construction period overlaps slightly with the CRIII construction project with a target date for opening in early 2003. The location on Arsenal Street is sufficiently distant that cumulative impacts would not be anticipated.

·                Hong Kong Station Extended Overrun Tunnel Project;

-    Environmental Impacts arising from this project are included in this EIA assessment.

·                Central, Western and Wan Chai West Sewerage Project;

-    The Central, Western and Wan Chai West Sewerage Project(CW3) comprises of reconstruction of interceptors and reticulation sewer system, two trunk sewers (between Smithfield and Pottinger Street and between Ice House Street and Wan Chai East Screening Plant), two pumping stations (Central Pumping Station and Wan Chai East Pumping Station) and an extension to the Wan Chai East Screening  Plant facilities. The CW3 works which will directly interface with the CRIII construction works will have been completed before the start of the CRIII works. There will not, therefore, be any overlap with the sewerage system works.

·                Justice Drive Extension Project;

-    The Justice Drive Extension (JDE) Project comprises of the construction of an extension to the existing flyover across Queensway onto the CRIII site and an extension from Supreme Court Road to Kennedy Road (known as the Queen’s Lines Link).  The Justice Drive Extension Project is needed to enhance north-south connectivity between the north shore and the hinterland areas of Hong Kong Island. The JDE is only about 450m long and consists of prestressed cast in-situ bridge deck.

-    The northern most section of the proposed Justice Drive Extension (JDE) is located within the CRIII construction works area (from Harcourt Road to the new primary distributor road P2).  This section of JDE is largely elevated carriageway but at its extreme  northern end it ramps down to connect with Road P2 at an at-grade junction.  There would therefore only be minor construction interfaces between the JDE and CRIII projects.

-       The programme for the Justice Drive Extension Project is currently under review by Transport Department.

-       The Kennedy Road Improvements and Queen’s Lines Link works have recently been degazetted.  The need and scope of the Justice Drive Extension, Kennedy Road Improvements and Queen’s Lines Link projects are, however, still being reviewed by Transport Department.

·                North Hong Kong Island Drainage Master Plan Study;

-       The currently proposed works are outside the limit of the CRIII study area.  The tentative programme for construction works as provided by DSD is as follows :

§      Lower Catchment Improvement Works      Dec 2004 – July 2012

§      HK West Drainage Tunnel Works              Sept 2006 – March 2011

Based upon the currently available information, no programme interface issues are anticipated from this project.

·                Wan Chai Development Phase II Project;

The scope of the Wan Chai Development Phase (WDII) project comprises:

§      Land formation for key transport infrastructure and facilities including the Central-Wan Chai Bypass, the Island Eastern Corridor Link, the North Island Line, ground level road connections to facilitate through traffic from Central to Wan Chai, a possible fourth harbour cross rail link, a Government Heliport, and a waterfront promenade with associated / supporting facilities;

§      Reprovisioning / protection of existing facilities and structures affected by the land formation; and

§      Extension, modification, reprovisioning or protection of existing stormwater drainage outfalls, sewerage outfalls, Wan Chai East Screening Plant and watermains affected by the land formation.

The WDII project provides essential land for the construction of major road and rail infrastructure required to relieve congestion on strategic east-west routes through Central, Wan Chai and Causeway Bay.  The WDII Project also provides the opportunity to create an attractive waterfront that can be used for a wide range of recreational and tourism related uses and functions.

The WDII works are currently planned to commence in early 2004 with completion of the project by early 2010.  Works would commence in the Wan Chai and Causeway Bay areas in early 2004, with the works adjacent to the CRIII area i.e. from Lung King Street up to the eastern side of the Hong Kong Convention and Exhibition Centre commencing in early 2006.

·                North Island Line Railway Project;

The North Island Line (NIL) comprises of the construction of a new underground railway for the northern shore of Hong Kong Island.  The railway will link the Airport Railway Hong Kong Station with Fortress Hill Station with intermediate stations at Tamar and Exhibition.

Preliminary design works for the NIL project commenced in late 2000.  At present there is no fixed programme for the construction of the NIL but it is proposed that some station protection works for the NIL be constructed as part of the CRIII project.  These are included in this CRIII assessment.

·                Refurbishment of Ferry Piers 4 – 6 Project.

-    In order to enhance the quality of the existing Ferry Piers 4 - 6 constructed as part of the Central Reclamation Phase I project, the Government is to award a contract to carry out refurbishment works to the piers.  The refurbishment works are expected to include provision of external glazing/cladding to the piers and replacement / upgrading of existing facilities as required.

-    It is understood that the extent of the works has yet to be finalised  and as such a programme  for implementation  of the works is not available.

4.3.4                                Table 4.3 shows the timings of interfacing projects.


 

Table 4.3  :  Timings of Interfacing Projects

 



5.                                          Traffic Noise

5.1.1                                The commercial, G/IC and other uses proposed for the CRIII will potentially be exposed to noise impacts from road traffic noise.  The section of the CWB within CRIII is in the form of a tunnel and thus operational noise impacts will not be an issue.  It is noted that there are no residential or educational uses, and that the commercial/G/IC uses are centrally air-conditioned.  The ceremonial space within the proposed Central Government Complex site is currently not defined as a noise sensitive receiver. However it is clear that such a space should be protected from high traffic noise levels.  The locations of CRIII NSRs and other noise predication locations are indicated on Figure 2.1 (refer to Chapter 2).

5.2                                      Assessment Methodology

5.2.1                                The Central Reclamation Phase III road network will ultimately form part of an overall road network including the Central Wan Chai Bypass and the road network constructed as part of the Wan Chai Development Phase II Project.  A cumulative assessment has therefore been conducted to assess the noise impacts associated with road traffic noise for the ultimate road network (ie. all roads within 300m of the assessment locations were considered).

5.2.2                                For the assessment traffic noise was predicted using the methodology provided in the UK Department of Transport Calculation of Road Traffic Noise (CRTN) 1988.  In accordance with this method, the assessment should be based on projected peak hour flows for the worst year within 15 years after opening of the roads.  The roads proposed under the CRIII project are scheduled to open in 2007.  Therefore, the traffic data for the year 2022 should be adopted for the assessment.  However, as the assessment is a cumulative assessment, it has adopted the "latest" design year for the ultimate road network of the CRIII, WDII and CWB projects - this being 2027.  The adoption of this date produces a conservative assessment for the CRIII road traffic noise.

5.2.3                                As the traffic flows at the major roads during the morning peak hour are generally higher than in the afternoon peak hour, the morning peak hour traffic flows were used for modelling.  The projected 2027 AM traffic flows as provided by the WDII traffic consultant and endorsed by the Transport Department are presented in Figure 5.1.

5.2.4                                Traffic speeds for new CRIII roads used in the assessment are summarised as follows:

Road                                                              Speed Used in Assessment

Roads P1 and P2                                          70 km per hour

All other roads                                                50 km per hour

The speed for roads P1 and P2, within the CRIII area, used in the assessment is the design speed for these roads as advised by the Transport Department.  It should be noted, however, that the Transport Department have also confirmed that all at-grade roads within CRIII will be subject to a speed limit of 50km per hour (refer to Transport Department letter included in Appendix D of this EIA Report).

5.2.5                                For the cumulative assessment, the road network, proposed building layout and all other features that could have noise screening or reflective effects, were digitised into the road traffic noise model.  The roads were divided into segments, each of which was assigned a road layout number.  The road layout defined the road width, opposing traffic lane separation, road surface type and traffic mix, flow and road design speed.  Hard ground as defined in CRTN was assumed throughout the study area.

5.2.6                                Representative noise prediction points were set to determine the characteristics of traffic noise from the surrounding roads.  NR1-NR3 represented the assumed quarters at the Central Barracks.  NR4-NR7 represented locations on the new ceremonial area to the north of the proposed Central Government Complex and NSR8 represented the open air theatre at the HKAPA.  Noise prediction points were also set for the City Hall (NR9) and HKAPA (NR10) as they are classified as sensitive receivers by EPD despite the fact that they are provided with air conditioning and hence do not rely on openable windows for ventilation.  The locations of the noise prediction points are shown on Figure 2.1 (refer to Chapter 2).  Where noise from the "new roads" exceeds 70dB(A) and with its contribution to the overall noise level more than 1dB(A), mitigation measures would be considered in accordance with the EIAO-TM.  "New roads" in CRIII include Roads P1, P2, D6, D8, D9 and D11.

5.2.7                                A sample of the modelling listing file for the cumulative assessment is included in Appendix D.

5.3                                      Prediction and Environmental Impacts

5.3.1                                The modelling results for the cumulative assessment as they apply to the CRIII noise prediction points are summarised in Table 5.1.

Table 5.1  :  Predicted Cumulative Traffic Noise Levels for Year 2027

Location

Floor

Existing Road Contribution dB(A)

New Road Contribution dB(A)

Total dB(A)

NR11

1

71.1

69.1

73.2

 

7

71.1

69.1

73.3

 

13

70.9

68.6

72.9

 

19

70.5

68.2

72.5

 

25

70.0

67.6

72.0

 

31

69.6

67.0

71.5

NR22

1

56.0

77.6

77.7

 

3

56.0

76.7

76.8

 

5

56.2

75.6

75.6

NR33

1

51.1

76.8

76.8

 

3

51.5

76.5

76.6

 

5

52.5

76.2

76.2

 

7

53.7

75.8

75.8

NR4

GL

53.2

55.0

57.2

NR5

GL

55.4

54.3

57.9

NR6

GL

53.2

55.8

57.7

NR7

GL

57.6

52.1

58.7

NSR8

GL

64.7

55.7

65.2

NR9

1

60.3

70.2

70.6

 

3

60.2

70.2

70.6

 

5

60.2

70.1

70.5

 

7

60.1

70.0

70.4

 

9

60.1

69.8

70.3

NR10

1

78.1

67.6

78.5

 

3

78.1

68.0

78.5

 

5

77.5

68.5

78.1

 

7

77.1

68.6

77.6

 

9

76.5

68.6

77.2

Notes:    1:         Only 1st to 3rd and 16th to 28th floors are for residential use.

                2:         Only Ground to 4th floors are for residential use.

                3:         Only Ground to 6th floors are for residential use.

                4:         New Roads to be constructed under CRIII works are illustrated on Figure 14.10 (refer to Chapter 14).

5.3.2                                The modelling results showed that there may be exceedance of the 70 dB(A) criteria at the Central Barracks facing Road P2. The maximum predicted noise level is 77.7 dB(A) for the first floor of Blake Block (NR2). However, the Secretary for Security has indicated that all rooms at the affected facades are provided with air conditioning and hence do not rely on open windows for ventilation.

5.3.3                                The predicted noise level at the HKAPA open-air arena (NSR8) is low, due to the fact that the arena is depressed and also has barriers of 2.75m in height around the top (refer also to paragraph 2.2.1.2). The ceremonial space has extensive screening by the buildings to the south. Road P2 will also be depressed to run below the ceremonial area. Predicated noise levels indicate that impacts should be acceptable for the proposed site usage.

5.3.4                                Noise levels were also calculated at the City Hall (NR9) and the HKAPA (NR10).  These buildings are provided with air conditioning and hence do not rely on openable windows for ventilation.  Noise levels at the HKAPA were calculated to be approximately 78 dB(A).  The dominant source was the existing Lung Wui Road.  The contribution Road P2 was not significant because of the distance (over 150 m).  At the City Hall (façade facing Road P2) noise levels were predicted to be 70-71 dB(A).  As these two buildings are provided with air conditioning and mechancial ventilation systems, it is expected that the indoor noise environment would not be adversely affected.

5.4                                      Mitigation of Adverse Environmental Impacts

5.4.1                                In view of the predicted noise levels at the HKAPA outdoor arena and ceremonial space within the Central Government Complex, no specific noise mitigation measures are required for these sites.

5.4.2                                Noise levels are predicted to exceed the 70 dB(A) criteria at the Central Barracks. Direct mitigation measures in the form of noise barriers are, however, not practicable at this location due to the need to maintain sightline requirements at the Central Barracks main entrance gate and the junctions of the adjacent Tim Wan Avenue/ Road P2 and Edinburgh Place/ Road P2.  Other direct mitigation measures listed in Section 6.1, Annex 13 of the EIAO-TM are also considered not practical.  It should be noted, however, that the affected facades are all provided with air conditioning so internal noise levels are unlikely to be affected.

5.5                                      Conclusion

5.5.1                                Potential road traffic noise impacts have been assessed as part of a cumulative assessment considering both the CWB and WDII projects as well as the CRIII project.

5.5.2                                Predicted noise levels at the HKAPA outdoor arena and ceremonial space to the north of the Central Government Complex were found to be low due to their physical location relative to the road network.  As such no specific mitigation measures are required for these sites.

5.5.3                                Predicted noise levels at the City Hall, HKAPA and Central Barracks were found to exceed the EIAO-TM noise criteria.  Direct mitigation measures were found to be not practical.  However, these buildings are all equipped with air-conditioning systems and do not rely on openable windows for ventilation.  As such, the indoor noise environment of these buildings is not expected to be adversely affected by traffic noise and no additional mitigation measures are required for them.

 

 

 


6.                                          Fixed Noise Sources

6.1                                      Introduction

6.1.1                                Three ventilation buildings are proposed for the CWB to maintain the tunnel air quality to within the EPD air quality guidelines. The ventilation buildings will, however, be a source of fixed noise from fresh air supply/extraction fans and their associated vent shafts. The seawater pumping stations will also be fixed noise sources. Given that they are below ground and buffered from potential receivers by open space areas, they are not likely to have a significant impact. The ventilation structure for the Hong Kong Station Extended Overrun Tunnel (EOT) will also be a fixed noise source.

6.2                                      Operational Noise Receivers

6.2.1                                There will be ventilation buildings for the CWB located on WDII and Central Reclamation Phase 1. There will be a ventilation building for the EOT within CRIII, 30m from Amythyst Block of the Central Barracks.  The seawater pumping stations will be to the north of the reclamation.  The ventilation structures and pumping stations will have the potential to impact on the users of the promenade.

6.3                                      Impacts

6.3.1                                The noise from the ventilation structures and pumping stations are subject to statutory control, hence the designs will have to ensure that the required criteria are met at the potential NSR of HKAPA.  As the sensitive receiver is located in the urban area and is directly affected by the influencing factors of Harcourt, Gloucester Roads and Fenwick Pier Street, the area sensitive rating is assumed to be “C” for the purpose of assessment in the EIA (based on the definitions in the ‘TM for the Assessment of Noise Places other than Domestic Premises, Public Places or Construction Sites’ of the Noise Control Ordinance).  According to Table 1A Noise Standards for Planning Purposes, EIAO TM, the predicted maximum noise level should be 5 dB(A) below the appropriate Acceptable Noise Levels (ANL) shown in Table 3 of the TM for the Assessment of Noise from places Other than Domestic Premises, Public Places.  In any event, the Area Sensitivity Rating assumed in this report is for indicative assessment only given that : details of plant and equipment to be located within these facilities are not available; and the building layouts are only provisional.  It should be noted that 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 shall bind the Noise Control Authority in the context of law enforcement against all the fixed noise sources being assessed.

 


6.3.2                                The distance between the Central Barracks and the EOT ventilation shafts is 65 metres.  Although the design of the ventilation shafts will have to satisfy the criteria set out in the Noise Control Ordinance, an assessment of the potential noise impact on the Central Barracks has been undertaken.  For the assessment the Central Barracks was assumed to have a conservative Area Sensitivity Rating of “B”.  The Acceptable Noise Level (ANL) for an ASR of “B” under the IND-TM is 55dB(A) at nighttime.  However, as the EIAO-TM recommends that the noise standard for fixed noise source is 5dB(A) below the appropriate ANL, a noise criteria of 50dB(A) at the Central Barracks was adopted for the assessment.  Given the relative separation of the ventilation shafts and the Central Barracks, a maximum Sound Power Level of 90dB(A) could be accepted in order to satisfy the noise criteria of 50dB(A).  The MTRC, who will be responsible for the design of the ventilation shafts have confirmed that it will be practicable to limit the sound power level at the shafts to 90dB(A).  It should, however, be noted that nothing in the EIA Report should bind the Noise Control Authority in the context of law enforcement against all fixed noise sources being assessed (refer also to paragraph 6.3.1).

6.3.3                                Noise impact from the CWB ventilation buildings on existing sensitive receivers falls outside the scope of the CRIII project. The landuses proposed within the CRIII project will not be sensitive to noise from the CWB ventilation buildings.

6.3.4                                It is unlikely that noise levels generated by the pumping stations will adversely impact the HKAPA due to their position underground and the distance between the sound source and the receiver.

6.4                                      Conclusion

6.4.1                                The design of the EOT ventilation buldings and ventilation shafts will be rquired to meet the requirements of the NCO.

 

 


7.                                          Construction Noise

7.1                                      Introduction

7.1.1                                The construction phase of CRIII has the potential to produce impacts from noise.  Although transient in nature, these can cause disturbance to work, leisure and sleep. However, because of the nature of the sources there is usually scope for mitigating the impacts.

7.2                                      Construction Noise Receivers

7.2.1                                There are no residential developments or other noise-sensitive uses within 300m of the works area which rely on opened windows for ventilation. The quarters at the Central Barracks may be considered noise sensitive, although all residential rooms have air conditioning and do not, therefore rely on openable windows for ventilation. The only other potential noise sensitive receiver is the Hong Kong Academy for Performing Arts. The building is, however, centrally ventilated and air-conditioned and the only sensitive use is the outside open air arena. This venue is rarely used, however, and is at a lower level than the surroundings. There are also 2.75m barriers around the top of the arena (refer also to paragraph 2.2.1.2).

7.3                                      Construction Methodology

7.3.1                                Introduction

7.3.1.1                Under the NCO, construction noise permits would be required for work during restricted hours (1900 to 0700 hours, all day Sundays and public holidays). This is the main method for controlling construction noise during restricted hours. The daytime criteria for construction noise are included in Chapter 3 of this report. In addition, recent revisions to the Technical Memorandum on Noise from Percussive Piling create more stringent controls. Alternative methods of piling (such as bored or vibratory piles) are, however, likely to be used during the construction of the new public landing steps and culverts.  Despite any description or assessment made in this EIA 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 Memorandum issued under the Noise Control Ordinance.  The Noise Control Authority will take account of contemporary conditions/ situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision on granting a CNP.  Nothing in this EIA shall bind the Noise Control Authority in making his decision.  If a CNP is to be issued, the Noise Control Authority shall include in it any condition he thinks fit.  Failure to comply with any such conditions will lead to cancellation of the CNP and prosecution action under the NCO.


7.3.1.2                Potential noise impacts from the development of the CRIII may arise from the following activities and operations :

·                demolition of existing water front structures;

·                dredging work and seawall construction;

·                piling and construction work for pumping stations, PLA Berth, public landing steps, reprovisioned ferry pier, culverts and associated services;

·                reclamation in-filling including noise from filling and compaction activities;

·                haulage vehicles (although minimum in number since transportation of spoil removed and reclamation materials will be by barge);

·                infrastructure construction (e.g. utilities, CWB tunnel, Hong Kong Station Extended Overrun Tunnel,  North Island Line protection works, Road P2 Underpass and surface road network); and

·                hinterland drainage improvement works.

7.3.2                                Construction Phasing

7.3.2.1                The construction of CRIII can be broadly set out in 8 stages covering a 55 month work programme. The main elements of each stage are detailed in section 4.2 and are illustrated in Figures 4.1 and 4.2 (refer to Chapter 4). In brief, the construction phasing is as follows: the construction work begins at the western end of the reclamation, including the construction of a reprovisioned ferry pier (Ferry Pier 8) and public landing steps; work then starts on the central section and the existing pier structures (Star Ferry Piers and Queen’s Pier) are demolished; the area between the western and central parts is then completed; and the eastern portion is also filled in.

7.4                                      Assessment Methodology

7.4.1                                There is some overlap between the Central Reclamation Phase III construction programme and those of the Wan Chai Development Phase II and Central-Wan Chai Bypass projects.  A cumulative assessment has therefore been conducted to assess the construction noise impacts arising from the works of the three projects, considering works from these other projects which fall within 500m of the receiver locations.  The Justice Drive Extension and Central Government Complex projects may have the potential to add to the impacts on CRIII NSRs.  However, the programme for both projects are unknown at this time and therefore it was not possible to include construction activities from these projects into the cumulative assessment.

7.4.2                                The cumulative construction noise assessment was carried out on a monthly basis from the CRIII project commencement in August 2002.  The construction tasks of the three projects that take place concurrently within 500m of a given NSR were considered to contribute to the cumulative impact at that NSR.

7.4.3                                In accordance with the EIAO, the methodology outlined in the GW-TM was used for the cumulative assessment of construction noise (excluding percussive piling).  Sound Power Levels (SWLs) of the equipment were taken from Table 3 of this TM.  Where no SWL is present in the TM, reference was made to BS5228, previous similar studies or from measurements taken at other sites in Hong Kong.

7.4.4                                In the cumulative assessment, it was assumed that all PME items required for a particular construction activity are located at the notional or probable source position of the segment where the activity is performed.  The assessment was 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, the 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 plants, their frequency of operation, and their distance from receivers.  The noise levels at NSRs were then predicted by adding up the SWLs of all concurrently construction tasks.

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

7.4.6                                Dredging, seawall and reclamation filling works has been assumed to be conducted for 16 hours per day on weekdays i.e. from 0700 to 2300 hours.  Other construction activities are  expected to be undertaken during normal daytime working hours i.e. from 0700 to 1900 hours on any day not being a Sunday or Public Holiday.  Assessment was therefore undertaken for both normal day time and restricted hours periods.  It should also be noted that other essential works may need to be conducted during restricted hours due to limitations on road closures, shut down of building air conditioning systems for transfer of supply etc.  These works which may include utility and pipeline connection works, drainage improvement works at Connaught Place etc. would, however, be subject to the issue of a CNP (refer to paragraph 7.3.1.1).

7.4.7                                Percussive piling may be required for marine pier foundation works.  A CNP is required for the carrying out of percussive piling between 0700 and 1900 hours on any day not being a general holiday. Percussive piling is prohibited outside these hours.  PP-TM sets out the requirements for working and determination of the permitted hours of operation.  The permitted hours of operation for carrying out of percussive piling work, subject to the issuance of a CNP, are listed below.

Amount by which Corrected Noise Level (CNL) exceeds Acceptable Noise Level (ANL), CNL-ANL

Permitted hours of operation on any day not being a general holiday

10 dB(A) < CNL-ANL

0800 to 0900 and 1230 to 1330 and 1700 to 1800

0 dB(A) < CNL-ANL £ 10 dB(A)

0800 to 0930 and 1200 to 1400 and 1630 to 1800

CNL - ANL £ 0 dB(A)

0700 to 1900

 

7.4.8                                The plant inventory list for the CRIII works confirmed by the  Engineer as being practical and practicable for completing the works within the scheduled timeframe, along with those of the concurrent WDII and CWB projects are listed in Appendix E for normal working hours and in Appendix G for restricted hours.  It should be noted, however, that the plant inventory list has been derived for an assumed construction method and sequence based upon best available information at the time of preparing this report.  The construction activities considered in the cumulative assessment, as they apply to the CRIII project, during each quarter for each CRIII NSR and the cumulative construction noise levels for the same NSRs are presented in Appendices F and H for normal working hours and restricted working hours respectively.

7.5                                      Prediction and Evaluation of Environmental Impacts withoug Mitigation

7.5.1                                Without mitigation and shielding, there is potential to exceed the 75 dB(A)  cirteria at all locations. Tables 7.1 and 7.2 show the range of noise levels experienced at the representative noise sensitive receiver and noise prediction loctions without mitigation.

Table 7.1: Summary of Unmitigated Construction Noise Levels Duirng Normal Working Hours

NR/NSR  (refer to Figure 2.1)

Minimum dB(A)

Maximum dB(A)

NR1

62

87

NR2

63

93

NR3

64

94

NSR8

56

81

NR9

65

93

 

Table 7.2: Summary of Unmitigated Construction Noise Levels Duirng Restricted Hours

 

Activity

Prediction Point

Minimum dB(A)

Maximum dB(A)

Dredging and Filling Works (1900 - 2300 hours)

Mandarin Hotel

58

69

Drainage Improvement Works in Connaught Place

Mandarin Hotel

76

76

7.6                                      Mitigation of Adverse Environmental Impacts and Evaluation of Residual Impacts

7.6.1                                In order to reduce the noise levels indicated in Tables 7.1 and 7.2, direct noise mitigation measures such as adopting quiet plant, errection temporary noise barriers and inclusion of existing screening barriers have been considered in a further noise assessment.  In this assessment, the recommended quiet PMEs have been taken from BS 5228 : Part 1 : 1997 and are known is be available in Hong Kong.  As confirmed by the Engineer, the quiet PMEs adopted for this assessment are considered practicable in completing the CRIII works within the scheduled timeframe (refer also to paragraph 7.4.8).  The quiet PMEs used in this assessment are :

 

Equipment Type

BS Ref

SWL, dB(A)

Air compressor

Table C7/16

96

Paver

Table C8/24

101

Hand-held breaker

Table C2/10

110

Breaker, excavator mounted

Table C8/13

110

Bulldozer

Table C3/27

109

Concrete lorry mixer

Table C6/35

100

Concrete pump

Table C6/36

106

Crane

Table C7/114

101

Dump truck

Table C9/27

105

Excavator / loader

Table C3/97

105

Grader

Table C9/11

110

Lorry

Table C9/27

105

Poker

Table C6/32

100

Road roller

Table C8/27

104

Vibratory roller

Table C3/116

106

                 With the use of quiet PMEs the noise levels at NSR/ NRs are reduced.  The predicted noise levels for this assessment (mitigated) are summarised in Tables 7.3 and 7.4.  Full details of the noise levels for this assessment are provided in Appendices F and H.

Table 7.3 : Summary of Mitigated Construction Noise Levels During Normal Working Hours

 

NR/NSR  (refer to Figure 2.1)

Minimum dB(A)

Maximum dB(A)

NR1

61

79

NR2

62

84

NR3

63

84

NSR8

55

73

NR9

64

83

Table 7.4 :  Summary of Mitigated Construction Noise Levels During Restricted Hours

 

Activity

Receiver

Minimum dB(A)

Maximum dB(A)

Dredging and Filling Works (1900 – 2300 hours)

 Mandarin Hotel

58

69

Drainage Improvement Works in Connaught Place

Mandarin Hotel

66

66

7.6.2                                The predicted noise levels at the Central Barracks (NR1, NR2, NR3) exceed the 75dB(A) guideline, in particular during the periods when the Extended Overrun Tunnel (EOT), North Island Line Protection Works (NIL) and road/drainage works are in progress at the northern boundary of the Central Barracks.  In order to reduce the construction noise levels at the Central Barracks during these periods, noise barriers (in the form of purpose built site hoarding between 3 - 5 m height with surface density of at least 7 kgm-3 and cranked top) placed as close as possible to the works should be adopted for the EOT, NIL and road/drainage works immediately to the north of the Central Barracks.  These would reduce noise levels by at least 5dB(A).    The exact details of these noise barriers, including final dimensions, will be determined during detailed design when exact construction activities are more clearly defined.  It should, however, be noted that the buildings within the Central Barracks are already provided with air conditioning and therefore the noise levels predicted after the adoption of quiet PMEs and movable noise barriers (for EOT, NIL and road/drainage works to the immedate north of the Central Barracks) would not result in adverse noise impacts to the buildings.

7.6.3                                The predicted noise levels at the City Hall (NR9) also exceed the 75dB(A) guideline, in particular during the period when Culvert F piling works are in progress to the immediate north of the City Hall.  In order to reduce the construction noise levels at the City Hall during this period, noise barriers (in the form of purpose built site hoarding between 3-5 in height with surface density of at least 7 kgm-2 and cranked top) placed as closed as possible to the works should be adopted for Culvert F piling works immediately to the north of the City Hall.  These would reduce noise levels by at least 5dB(A). The exact details of these noise barriers, including final dimensions, will be determined during detailed design when exact construction activities are more clearly defined.  It should, however, be noted that the City Hall has central air conditioning and therefore the nosie levels predicted after the adoption of quiet PMEs and movable noise barriers (for Culvert F piling works to the immedate north of the City Hall) would not result in adverse noise impacts to the City Hall.

7.6.4                                The noise levels at the HKAPA open air arena as presented in Table 7.3, from CRIII works only, are predicted not to exceed the 75dB(A) guideline.  The 75dB(A) guideline is appropriate as the HKAPA have confirmed that the facility does not rely on unaided voice communication and is not used for educational purposes.  The cumulative assessment of both CRIII and WDII works (presented in Appendix F) indicates that the maximum noise level at the HKAPA open air arena will be 75 dB(A).  Whilst this level is equivalent to the guideline level, the screening effect of the existing barriers at the top of the arena will reduce the predicted noise levels by up to 5 dB(A) and ensure no exceedance of the guideline.

7.6.5                                For construction works during restricted hours, the predicted noise levels at the Mandarin Hotel from Stormwater Drainage Im provement Works at Connaught Place is 66 dB(A) in the worst case (see Table 7.4).  These works have to be conducting during restricted hours due to limitations on road closure of this busy road in the Central District.  However, the location and orientation of Jardine House effectively shields the Mandarin Hotel from noise generated by these works.  No direct mitigation measures would therefore be required to satisfy nighttime noise guidelines for the Mandarin Hotel.

7.6.6                                Dredging, seawall and reclamation filling works have been assumed to be conducted for 16 hours per day i.e. up to 11pm.  A Construction Noise Permit (CNP) will be required, with the application for the CNP and responsibility for maintaining the noise limits to rest with the Contractor.  The assessment indicates that noise levels would be up to 69 dB(A) at the Mandarin Hotel.  On the assumption that the ASR will be "C" due to the proximity of Connaught Road, the Contractor should be able to obtain a CNP for construction works up to 11pm.  However, there are some factors affecting the assessment results of a CNP appication, such as the assigning of Area Sensitivity Rating, Acceptable Noise Levels etc.  The Noise Control Authority would decide these at the time of assessment of such an application based on the contemporary situations/ conditions.  It should be noted that the situations/ conditions around the site may change from time to time.  The Authority may make correction for multiple permit situations if in the opinion of the Authority the NSR will be materially affected by noise from construction work associated with more than one CNP.  The Authority may make such corrections to the relevant noise levels as it considers appropriate having regard to standard acoustical principlies and practices. The Area Sensitivity Ratings assumed in this EIA Report are for indicative assessment only (refer also to paragrah 7.3.1.1).

7.6.7                                Connections to cooling water pipes and utilities may also require to be carried out duirng restricted hours, as road closures will be necessary.  The Contractor should approach the Noise Control Authority to apply for a Construction Noise Permit before the works commence.  In applying for a Construction Noise Permit, the applicant (i.e. the Contractor) shall be required to demonstrate to the satisfaction of the Noise Control Authority that the Sound Power Level of the quiet PMEs and/or the noise reduction effect of other mitigation measures to be adotped, otherwise, values in the GW-TM would be used in assessing the application.

7.6.8                                In addition to the mitigation measures, detailed earlier in this section, the good site practices listed below should also be adopted by the Contractor to further ameliorate the noise impacts.  Although the noise mitigating effects are not easily quantifiable and the benefits are specific to this site and operating conditions, good site practices are easy to implement and do not impact upon the works schedule.

·            Only well-maintained plant should be operated on-site and plant should be serviced regularly during the construction programme.

·            Silencers or mufflers on construction equipment shoud be utilised and should be properly maintained during the construction programme.

·            Mobile plant, if any, should be sited as far away from noise sensitive facilities as possible.

·            Machines and plant (such as trucks) that may be in intermittent use should be shut down between works periods or should be throttled down to a minimum.

·            Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from nearby noise sensitive facilities.

·            Material stockpiles and other structures shoud be effectively utilised, wherever practicable, in screening noise from on-site construction activites.

7.7                                      Conclusion

7.7.1                                The provision of noise mitigation measures in the form of limiting equipment sound power levels (i.e. use of quiet equipment) and movable noise barriers (in the form of purpose built site hoarding) will effectively mitigate against high noise levels, particularly at the Central Barracks and City Hall.  Although noise levels after mitigation slightly exceed this 75dB(A) guideline, all affected buildings are, however, provided with air-conditioning and therefore adverse noise impact is not expected at the indoor areas of these buildings.

7.7.2                                CNPs will be required for construction works to be carried out during restricted hours i.e. 7pm to 7am on any day not being a general holiday and at any time on a general holiday, including Sunday.

 

 


8.                                          operational AIR QUALITY

8.1                                      Introduction

8.1.1                                During the operational phase, vehicular emissions from the proposed primary distributor and the associated road network will be the major sources of air pollutants. There will also be emissions from the CWB ventilation buildings.  As advised by the MTRC the ventilation shafts associated with the Hong Kong Station Extended Overrun Tunnel (EOT) will, under normal operating conditions, only emit clean, unpolluted air and will, therefore, not affect air quality in the area. Only in the event of a fire would smoke be emitted but this would only be a short-term incident under emergency conditions and, due to its low probability of occurrence, is not considered to be a major impact.

8.2                                      Background Air Quality

8.2.1                                The background air quality conditions are dominated by the influence of traffic exhaust emission pollutants. There are no major existing or proposed industrial activities in the study area and the urban area consists mainly of commercial premises, hotels and other uses such as City Hall, Ferry Piers, Post Office, Police Headquarters and Central Barracks. The nearest EPD fixed air quality monitoring station is the Central / Western station. Concentrations of TSP and NO2 are monitored at the station. Annual averages of the pollutants for the year 1999 were employed as the background of the study area. Table 8.1 gives the measured concentrations.

Table 8.1  :  Measured Annual Average Pollutant Levels µg/m3
at Central/Western Station (1999)

Pollutant

Average (µgm-3)

Nitrogen Dioxide (NO2)

56

Carbon Monoxide (CO)

1,179

Total Suspended Particulates (TSP)

81

Respirable Suspended Particulates (RSP)

53

8.3                                      Representative Sensitive Receivers for Operational Air Quality Impact

8.3.1                                Air Quality Objectives (AQOs) are defined as ambient standards, therefore, all buildings (or fresh air intakes) in the adjacent area will be considered sensitive. There are no residential developments in the study area but any proposed active recreational uses are considered sensitive to air quality. Representative air sensitive receivers (ASRs) have been identified in Section 2.2.2.

8.4                                      Assessment Methodology

8.4.1                                Introduction

8.4.1.1                Potential air quality impacts during the operational phase of the CRIII project include the following pollutant sources :

·                Background pollutant levels within and adjacent to the CRIII reclamation area;

·                Vehicle emissions from open sections of existing and planned road networks;

·                Tunnel portal and ventilation building emissions from the CWB; and

·                Portal emissions from the existing underpasses, the planned Road P2 underpass and the planned deckovers along Road P1, Road P2 and Connaught Road Central.

8.4.2                                Vehicle Emissions from Open Sections of Existing and Planned Road Networks

8.4.2.1                The Central Reclamation Phase III road network will ultimately form part of an overall road network including the Central Wan Chai Bypass and the road network constructed as part of the Wan Chai Development Phase II project.  A cumulative assessment has therefore been conducted to address the air quality impacts associated with the ultimate road network.

8.4.2.2                The CALINE4 dispersion model was used for calculation of the 1-hour NO2, 24 hour NO2, 24-hour RSP and 1-hour CO concentrations.  Open sections of existing and planned road networks within 500 m from the boundary of the CRIII reclamation area were considered in the model and are listed as follows :

·                New roads in CRIII;

·                New roads in WDII;

·                The CWB; and

·                The existing roads (including Gloucester Road, Harcourt Road, Connaught Road Central, Queensway, and Des Veoux Road Central).

8.4.2.3                For the worst case scenario, the morning peak hour traffic flow and vehicle mix predicted by the WDII traffic consultant, for the ultimate road network in 2027, was used for the cumulative assessment.  Figure 5.1 shows the projected 2027 morning peak hour traffic flows and vehicle composition (refer to Chapter 5).

8.4.2.4                The most up-to-date vehicular emission factors (Fleet Average Emission Factors – EURO3 Model) available from the EPD are for the year 2011 and these were adopted for the cumulative assessment.  It is, however, believed that the 2027 emission rates will be lower than those of 2011, as more vehicle will be fitted with advanced emission control system in the future.  The predicted results are therefore conservative.

8.4.2.5                The composite emission factors for the road links were calculated as the weighted average of the emission factors of different types of vehicles.  Four vehicle categories were adopted.  As a worst-case scenario, maximum emission factors within the same category were used for the assessment.  The vehicular emissions for different vehicle categories are listed in Table 8.2.

 

Table 8.2  : Emission Factors for Year 2011 for Different Vehicle Categories (EURO3)

Pollutant

Emission Factors for 2011 (EURO3), g/km - veh

PV (1)

LGV (2)

HGV (3)

PT (4)

NOx

0.73

1.53

3.84

6.8

RSP

0.03

0.16

0.53

0.69

CO

1.87

2.25

6.45

7.38

Notes:           (1)          Private Vehicles (PV) include taxi and private car.

(2)                Light Goods Vehicles (LGV) include passenger van and light goods vehicle.

(3)                HGV stands for Heavy Goods Vehicles.

(4)                Public Transport (PT) includes all types of buses.

8.4.2.6                Peak hour traffic flow within and adjacent to the CRIII development area will occur during daytime.  The night time traffic flow will be low (about 10% of peak flow) and the worst case scenario will therefore not be encountered during night time.

8.4.2.7                In order to calculate the cumulative pollutant concentrations from different models (CALINE4 and ISCST3) in the later part of the assessment, the dispersion modelling was undertaken using 360 predefined separate meteorological conditions and the highest predicted pollutant concentration amongst the 360 wind directions were identified.  The following summarises the meteorological conditions adopted in the air quality modelling using the CALINE4 model :

·                Wind speed                       :                       1 m s-1

·                Wind direction                   :                       360 wind directions

·                Resolution                         :                       1°

·                Wind variability                  :                       24°

·                Stability class                    :                       D

·                Surface roughness            :                       1 m

·                Mixing height                      :                       500 m

8.4.2.8                The CALINE4 model calculates hourly concentrations only.  The 24-hour average concentrations were calculated by multiplying the peak 1-hour concentration by a factor of 0.4.

8.4.2.9                Sample Computer Output from the CALINE 4 model used for the cumulative vehicle emission impact assessment are included in Appendix I.

8.4.3                                Portal and Ventilation Building Emissions

8.4.3.1                The Industrial Source Complex Short Term (ISCST3) dispersion model was used to predict portal and ventilation building emissions that would affect the three project sites of CRIII, WDII and CWB (as part of the cumulative air quality modelling assessment).

8.4.3.2                Tunnel portal and ventilation building emissions that may affect the CRIII ASRs are :

·                Tunnel portal and ventilation building emissions from the tunnel section of the CWB;

·                Portal emissions from the planned Road P2 underpass;

·                Portal emissions from the existing underpasses along Connaught Road Central; and

·                Portal emissions from the planned deckovers along Road P1, Road P2 and Connaught Road Central.

It should be noted that the air quality inside the planned Road P2 underpass and deckovers along Road P1, Road P2 and Connaught Road Central will need to meet the air quality guidelines stipulated in the Practice Note on Control of Air Pollution in Vehicle Tunnel.

8.4.3.3                For the CWB, three ventilation buildings have been proposed to discharge the tunnel vitiated air :

·                West Ventilation Building (WVB) : for extracting vitiated tunnel air from Trunk Road Westbound;

·                Central Ventilation Building (CVB) : for extracting vitiated tunnel air from Slip Road F and Wanchai Bypass Westbound;

·                Eastern Ventilation Building (EVB) : for extracting vitiated tunnel air from Trunk Road Eastbound and Wanchai Bypass Eastbound.

8.4.3.4                The locations of the portals and ventilation building that may affect the CRIII ASRs are shown on Figure 8.1.

8.4.3.5                The portal and ventilation building emissions as provided by the ventilation design engineer are summarised in Table 8.3

Table 8.3  : Portal and Ventilation Building Emissions

Type

Emission Rate (g s-1)

NO2*

CO

RSP

Portal Emission

Trunk Road Eastbound

0

0

0

Wanchai Bypass Eastbound

0.02050

0.90250

0.00725

Slip Road F

0

0

0

Wanchai Bypass Westbound

0.09225

4.47750

0.02602

Trunk Road Westbound

0.11750

4.60500

0.03819

Ventilation Building Emission

EVB – Trunk Road Eastbound

0.84271

18.14583

0.26674

EVB – Wanchai Bypass Eastbound

0.05668

2.49515

0.02176

CVB - Slip Road F

0.12222

2.35556

0.01092

CVB – Wanchai Bypass Westbound

0.04884

2.37044

0.00867

WVB – Trunk Road Westbound

0.38364

14.23364

0.11457

Note:   * Based on 20% NO2/NOx conversion in ambient condition.

8.4.3.6                The preliminary design of the ventilation buildings (including minimum discharge heights, exhaust directions, handling capacity of ventilation buildings and exit velocity) is summarised in Table 8.4.  For the cumulative air quality assessment, the minimum height of stack was used as a worse case scenario in modelling.

 

Table 8.4  : Design of Ventilation Buildings

 

Maximum capacity
(m3 s-1)

Exit velocity
(m s-1)

Minimum discharge height (meters above ground)

Exhaust direction

 

EVB – Trunk Road Eastbound

570

8

25

Vertical

EVB – Wanchai Bypass Eastbound

200

8

25

Vertical

CVB – Slip Road F

180

8

15

Vertical

CVB – Wanchai Bypass Westbound

100

8

15

Vertical

WVB – Trunk Road Westbound

420

8

15

Vertical

8.4.3.7                The portal emissions (NO2, RSP and CO) for the existing underpasses along Connaught Road Central, the planned underpass at Road P2 and the planned deckovers of Road P1, Road P2 and Connaught Road Central were calculated based on the vehicle emissions (EURO3) and the vehicle flow rate in 2027 as provided by the WDII traffic consultant.

8.4.3.8                Portal emissions were modelled in accordance with the Permanent International Association of Road Congress Report (PIARC, 1991).  The volume of pollutants was assumed to eject from the portal as a portal jet such that 2/3 of the total emissions were dispersed within the first 50 m of the portal and 1/3 of the total emissions within the second 50 m of the portal.

8.4.3.9                As indicated in Section 8.4.2.7, 360 predefined separate meterologoical conditions were used in the cumulative assessment.  The following summarises the meteorological conditions adopted in the air quality modelling using the ISCST3 model :

·                Wind speed                       :      1 m s-1

·                Wind direction                   :      360 wind directions

·                Resolution                         :      1°

·                Stability class                    :      D

·                Mixing height                      :      500 m

·                Emission temperature       :      7° above ambient

8.4.3.10            A sample of computer output from the ISCST3 modelling is provided in Appendix J.

8.4.4                                Combined Impact of Road Traffic and Portal / Ventilation Building Emissions

8.4.4.1                As indicated in Section 8.4.1, the emissions from open sections of existing and planned roads will combine with emissions from tunnel portal and ventilation buildings for the CWB and new and proposed road underpasses and deckovers to affect the air quality at the CRIII ASRs.  The pollutant concentrations at the CRIII ASRs, at different wind directions (1 degree resolution) have therefore been predicted by combining the data from both the CALINE 4 and ISCST 3 models, where

·                The CALINE 4 model was used to predict the open road emissions from the existing and planned road networks of CRIII, WDII and CWB; and

·                The ISCST3 model was used to predict road portal and ventilation shaft emissions.

8.4.4.2                The combined pollutant concentrations at each CRIII ASR, at each specific wind direction, were calculated by summing the results from the two models.  The highest pollutant concentrations at each CRIII ASR, amongst the 360 wind directions, was identified as the worst predicted combined pollutant concentration.

8.5                                      Prediction and Evaluation of Environmental Impacts on CRIII ASRs

8.5.1                                Taking into account the vehicle emissions from open road networks, portal and ventilation building emissions from the CWB, existing and planned underpasses and deckovers and the background pollutant concentrations, the cumulative 1-hour NO2, 24-hour NO2, 24-hour RSP and 1 hour CO concentrations at 360 wind directions were predicted and the highest pollutant concentration at each existing and future CRIII ASRs (refer to Tables 2.1 and 2.2 in Chapter 2) under the worst wind direction were calculated.

8.5.2                                In order to have a full picture of the vertical dispersion, pollutant concentrations at various levels (1.5m to 150m above ground) were calculated.  From those results it was found that the maximum predicted pollutant concentrations were at 1.5m above ground.  Table 8.5 summaries the predicted cumulative 1-hour NO2, 24-hour NO2, 24-hour RSP and 1-hour CO concentrations at 1.5m above ground.

Table 8.5  :  Predicted Cumulative 1-hour Average NO2 , 24-hour Average NO2,
24-hour Average RSP and 1-hour Average CO concentrations at the CRIII Existing
and Future ASRs at 1.5m above ground
level

 

 

Predicted Concentration (mgm- 3 )*

ASR No.

ASR Description

1-Hour NO2

24-Hour NO2

24-Hour RSP

1 Hour CO

A6

Crocodile Building

212

118

80

2718

A7

Hang Seng Bank Headquarters

237

128

84

2998

A8

Exchange Square III

264

139

89

3076

A9

Exchange Square I & II

153

95

71

2004

A10

Exchange Square I & II

192

110

77

2324

A11

Jardine House

144

91

69

1902

A12

Jardine House

196

112

76

2401

A13

Statue Square

234

127

82

2892

A14

Hong Kong Club Building

278

145

90

3234

A15

City Hall

126

84

64

1989

A16

City Hall

254

135

86

2943

A17

Furama Hotel

277

144

90

3235

A18

Hutchison House

241

130

83

3025

A19

Bank of America Tower

264

139

87

3090

A20

Central Barracks

127

84

64

2020

A21

Central Barracks

205

116

77

2520

A22

Far East Financial Centre

246

132

84

3014

A23

Admiralty Centre

272

142

88

3293

A24

Harcourt Garden

248

133

85

2997

A25

Police Headquarters

245

131

85

2914

A26

HK Academy for Performing Arts

153

95

69

2162

A27

Arts Centre

179

105

72

2386

A28

Citic Tower

138

89

65

2225

A29

Servicemen's Guides Association

134

87

65

2091

A30

HK Academy for Performing Arts

138

89

66

2457

A31

Shui On Centre

143

91

67

2620

A33

Pedestrian Plaza

131

86

64

3053

A34

HKCEC Extension

129

85

63

3089

A67

Comprehensive Development Area Site

147

92

67

3386

A68

Airport Railway Hong Kong Station

225

124

77

6621

A69

Future Commercial Buildings and Landscaped Deck east of new Outlying Islands Ferry Piers (CDA site)

136

88

68

2399

A70

Proposed Central Government Complex

135

88

65

2049

A71

New G/IC site south and east of Citic Tower (to include the redeveloped HK Red Cross Headquarters)

166

100

71

2196

A72

New G/IC site north of Citic Tower

158

97

69

2407

A73

Waterfront related commercial and leisure uses

147

92

67

2186

A74

Open space promenade along new reclamation edge

131

86

64

1939

A75

Festival Market

125

83

64

1820

A76

Waterfront related commercial and leisure uses

141

90

67

2435

A77

Waterfront related commercial and leisure uses

167

100

70

3022

A78

Grade A Office

137

89

66

2500

*  Background Concentrations are included

8.5.3                                The predicted cumulative maximum 1-hour NO2 concentrations at 1.5m, 10m, 20m, 30m, 70m and 110m above ground level are shown in Figures 8.2a -8.2f.  The maximum predicted cumulative 24-hour NO2, 24-hour RSP and 1-hour CO concentration contour plots at 1.5m above ground level are shown in Figures 8.3 - 8.5.

8.6                                      Mitigation Measures

8.6.1                                Compliance with the 1-hour NO2, 24-hour NO2 and 24-hour RSP is predicted at CRIII. Mitigation measures are therefore not required. Cumulative impacts on existing ASRs in the Central area will also comply with AQOs, the results of the cumulative impacts assessment are presented in Table 8.5.

8.6.2                                The Hong Kong Planning Standards and Guidelines, however, recommend that a 20 metre buffer distance be provided from trunk roads and primary distributors to areas of both active and passive recreational use. This recommendation should be applied to the waterfront promenade area.

8.7                                      Conclusion

8.7.1                                Modelling results indicate compliance with Air Quality Objectives within the CRIII area.

 

 


9.                                          Construction Air Quality

9.1                                      Introduction

9.1.1                                The APCO places statutory limits (Air Quality Objectives (AQOs)) on typical air pollutants and the maximum allowable concentrations which should not be exceeded. In addition, a TSP criteria of 500 mgm-3 (1-hour average) is included in the TM of the EIAO for assessment purposes. These standards are given in Section 3.

9.2                                      Construction Dust Generating Activities

9.2.1                                The major dust generating activities for the CRIII project will be :

·                Dredging and Reclamation activities:  For the reclamation method to be used, the reclamation fill material would be either surplus soft fill material from land formation projects or marine sand fill, delivered by barge and generally bottom dumped.  As the reclamation fill material will generally be bottom dumped, potential for dust generation is minimised.

·                Wind Erosion: Wind erosion of open site areas will have potential for dust generation, dependent on the wind speed.

·                Vehicles Movements Over the Site and Haul Roads: Vehicles movements over unpaved areas of the site will have potential for dust generation.

·                Entrusted works (MTRC Hong Kong Station Extended Overrun Tunnel,  North Island Line Protection Works and the Central and Wanchai Bypass): These activities will involve provision of diaphragm walls (or sheet piles) in the new reclamation, excavation and concreting activities.

·                Infrastructure construction: Construction of the roads and provision of services will require limited site clearance, excavations and materials movement.

9.3                                      Construction Dust Impact Assessment Methodology

9.3.1                                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 will settle out near the source and particles that are 30 to 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.

9.3.2                                In accordance with the USEPA AP-42, nine particle size classes were used in the construction dust assessment for CRIII.  Their averaged diameters 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 in each class was estimated to be 4%, 7%, 4%, 3%, 7%, 5%, 4%, 17% and 49%, respectively.

 

9.3.3                                The Fugitive Dust Model (FDM) was used to predict the TSP concentration levels.  The emission rates for different construction activities were based upon the USEPA Compilation of Air Pollutant Emission Factors (AP-42), 5th edition.  Table 9.1  shows the emission factors used in this assessment.

Table 9.1  : Emission Factors for Construction Activities

 

Construction Activities

Emission Factor, AP-42, 5th edition

Road Construction, Building Construction and Material Handling (as Heavy Construction)

S.13.2.3.3

Material Handling (Excavation and Backfilling)

S.13.2.4

Truck Haulage

S.13.2.2

Wind Erosion

S.11.9.4

9.3.4                                The 1997 meteorological data from the Hong Kong Observatory (Central Station) was used in the FDM to predict the 1-hour and 24-hour average TSP concentrations.  The data includes hourly averaged wind speed, wind direction, stability class, ambient temperature and mixing height.

9.3.5                                In addition to the CRIII works, dust will be generated from WDII and CWB works constructed at the same time as the CRIII works.  A summary of the major dust generating activities for the CRIII project and for WDII and CWB projects that will be conducted at the same time as the CRIII works are presented in Figure 9.1.  This figure also illustrates the periods when dust generating activities from the these projects will occur concurrently.  Based upon the information contained in Figure 9.1, eight worst case dust generation scenarios were identified for the entire CRIII construction period.  These worst case scenarios are detailed in Table 9.2.

 


 

Table 9.2  : Different Major Dust Generating Activities in the Worst Case Scenarios during the construction of CRIII

Period

2002 - 2003

2004

2005

2006 - 2007

Worst month

March 2003

August 2003

March 2004

October 2004

February 2005

May 2005

August 2005

July 2006

Activities

Scenario 1

Scenario 2

Scenario 3

Scenario 4

Scenario 5

Scenario 6

Scenario 7

Scenario 8

1

Backfilling - IRAW

Ferry Pier 8 Construction

Backfilling - IRAE

Culvert J Extension

CWB in IRAE

CWB in IRAE

Culvert F Temporary Extension

Culvert F Extension

2

EOT in IRAE

Public Landing Steps

Preliminary for Cooling Water Systems in IRAE

EOT in IRAE

Backfilling - FRAW

Backfilling - FRAW

EOT in FRAW

Drainage & Utilities

3

North Island Line Protection Works

EOT in IRAE

Culvert J Extension

CWB in IRAE

Culvert F Temporary Extension

Culvert F Temporary Extension

CWB in FRAW

Roads

4

Public Transport Facilities behind Piers 4 - 7

North Island Line Protection Works

EOT in IRAE

Hinterland Drainage at Connaught Place

EOT in FRAW

EOT in FRAW

Culvert K Extension

Man Yiu Street Footbridge

5

 

 

CWB in IRAE

WDII Works Scenario 1

WDII Works Scenario 2

Backfilling - FRAE

CWB in FRAE

WDII Works Scenario 5

6

 

 

North Island Line Protection Works

 

 

WDII Works Scenario 3

Road P2 Underpass

CWB Works - Central

7

 

 

Hinterland Drainage at Connaught Place

 

 

 

WDII Works Scenario 4

 

Note:      


9.3.6                                The working hours of all land construction sites were assumed to be 12 hours.  Truck speeds within the project sites were limited to 10 km per hour.

9.3.7                                Daily TSP concentrations were calculated as follows :

Daily TSP concentration = 12/24* (1-hour average maximum TSP concentration during working hours) +12/24* (1-hour average maximum TSP concentration during non-working hours) + Background.

9.3.8                                The calculation of dust emission factors for CRIII construction activities are included in Appendix K.  The calculation of dust emission factors for WDII and CWB activities that will overlap with the CRIII works are included in Reference 8.  Sample computer output from the FDM used for the construction dust impact assessment is provided in Appendix L.

9.3.9                                For daytime assessments, wind erosion has not been included as its contribution relative to other construction activities is insignificant.  For nighttime assessments, wind erosion has been included as its contribution will be significant due to the fact that other major construction activities will not be in progress.

9.4                                      Prediction and Evaluation of Environmental Impacts

9.4.1                                As the majority of construction activities will be undertaken at ground level, the cumulative dust impacts for the CRIII, WDII and CWB works were modelled for a height of 1.5 m above ground level at ASRs.  Detailed breakdowns, of the dust impacts from the various construction scenarios considered are provided in Appendix M.

9.4.2                                The cumulative 1-hour TSP and 24-hour TSP concentrations for the CRIII and WDII and CWB construction activities, as appropriate, are given in Tables 9.3 and 9.4.

 

Table 9.3  : Predicted Cumulative 1-hour Average TSP Concentrations for Scenarios 1 to 8 (Unmitigated)

 

ASRS

Predicted Concentration (mg m -3) under different scenarios

 

 

Scen. 1

Scen. 2

Scen. 3

Scen. 4

Scen. 5

Scen. 6

Scen. 7

Scen. 8

Max.

A6

131.2

133.2

175.6

182.3

532.4

591.1

238.1

445.6

591.1

 

A7

136.3

138.4

192.0

195.1

568.3

636.6

254.7

448.2

636.6

 

A8

147.1

149.7

221.7

220.5

649.3

727.6

284.0

501.3

727.6

 

A9

188.8

193.0

520.7

578.4

922.4

1006.5

424.4

623.8

1006.5

 

A10

180.5

184.6

576.8

628.8

722.3

780.0

345.5

510.8

780.0

 

A11

208.9

214.3

233.5

289.3

845.5

906.3

385.3

605.4

906.3

 

A12

201.2

206.3

228.3

290.5

762.9

807.1

340.3

537.1

807.1

 

A13

245.5

251.5

261.3

241.7

789.5

882.7

332.9

496.7

882.7

 

A14

294.6

303.4

308.9

264.7

932.2

1039.7

360.8

594.3

1039.7

 

A15

653.8

685.1

517.6

354.7

2582.3

2667.9

851.3

1310.7

2667.9

 

A16

329.7

339.0

332.2

276.4

1046.2

1153.7

401.4

696.6

1153.7

 

A17

319.6

331.7

357.5

292.3

1123.9

1250.8

383.0

608.2

1250.8

 

A18

300.7

315.6

380.3

326.5

1318.1

1456.9

390.0

556.4

1456.9

 

A19

283.4

292.6

374.1

336.8

1382.2

1501.0

395.5

540.0

1501.0

 

A20

1043.4

1045.5

1267.4

556.2

2134.1

2306.9

585.5

999.1

2306.9

 

A21

409.6

426.5

484.8

350.1

1914.7

2056.4

443.7

729.5

2056.4

 

A22

224.8

236.7

298.3

324.0

974.8

1185.6

375.2

517.8

1185.6

 

A23

201.0

220.1

271.0

296.2

762.1

930.4

326.7

452.2

930.4

 

A24

197.9

213.5

267.5

325.6

577.6

824.5

337.5

515.9

824.5

 

A25

198.2

203.0

309.7

365.0

549.8

979.8

398.3

526.0

979.8

 

A26

226.2

229.8

456.9

435.7

578.1

1296.1

494.4

648.1

1296.1

 

A27

166.8

169.3

261.2

390.9

607.4

1337.9

515.9

808.7

1337.9

 

A28

307.6

312.0

518.5

506.1

731.2

1337.6

478.7

701.1

1337.6

 

A29

257.4

262.3

469.5

594.6

711.9

1802.1

638.8

822.4

1802.1

 

A30

183.5

187.6

295.6

405.5

615.7

1731.7

628.6

813.4

1731.7

 

A31

154.3

157.0

223.8

390.4

623.2

1384.2

533.8

904.4

1384.2

 

A33

147.5

150.3

205.6

392.6

677.3

2513.1

879.7

1033.2

2513.1

 

A34

101.0

102.0

120.1

337.4

548.4

1593.2

721.1

1679.9

1679.9

 

* Background concentrations are included.

 

 

 

Table 9.4  : Predicted Cumulative 24-hour Average TSP Concentration for Scenarios 1 to 8 (Unmitigated)

 

ASRS

Predicted Concentration (mg m –3) under different scenarios

 

 

Scen. 1

Scen. 2

Scen. 3

Scen. 4

Scen. 5

Scen. 6

Scen. 7

Scen. 8

Max.

A6

109.1

108.3

133.1

132.7

312.9

343.6

162.0

268.0

343.6

 

A7

111.7

111.0

141.6

139.2

331.1

366.2

170.5

269.2

366.2

 

A8

117.7

116.8

157.2

151.9

372.7

412.3

185.8

296.3

412.3

 

A9

139.5

139.4

309.1

331.2

513.4

554.7

257.6

360.7

554.7

 

A10

134.5

135.0

336.7

356.5

410.9

438.8

216.4

302.2

438.8

 

A11

148.9

150.6

166.6

187.0

473.5

502.9

236.8

349.7

502.9

 

A12

144.8

146.4

163.6

187.6

431.2

452.2

213.9

314.9

452.2

 

A13

166.8

170.0

181.5

163.5

443.2

489.5

210.0

295.1

489.5

 

A14

191.4

197.0

206.8

175.3

515.8

569.2

224.2

345.0

569.2

 

A15

372.7

396.2

323.0

220.8

1347.5

1388.6

472.7

706.1

1388.6

 

A16

209.3

215.6

219.8

181.1

573.8

626.1

244.8

397.3

626.1

 

A17

203.9

211.8

232.1

189.4

612.4

676.2

235.6

351.9

676.2

 

A18

194.2

203.4

244.3

206.9

709.5

780.8

239.1

325.3

780.8

 

A19

185.4

191.4

241.0

212.0

741.4

803.9

242.0

316.6

803.9

 

A20

566.7

584.5

719.3

322.7

1124.8

1212.5

339.4

547.2

1212.5

 

A21

249.3

261.4

300.2

218.6

1009.4

1081.4

266.6

412.5

1081.4

 

A22

155.4

162.3

201.1

206.2

536.7

646.1

231.6

304.5

646.1

 

A23

143.2

153.6

187.1

192.1

429.5

517.6

207.4

271.5

517.6

 

A24

141.3

150.1

185.5

207.2

336.8

465.9

213.0

303.6

465.9

 

A25

141.3

144.7

209.0

228.1

323.7

544.4

244.3

308.6

544.4

 

A26

155.5

158.6

289.0

267.9

342.5

712.8

293.9

371.4

712.8

 

A27

125.3

127.1

182.6

244.7

355.3

729.3

304.9

451.5

729.3

 

A28

196.6

201.5

327.6

300.8

418.2

734.8

284.9

396.8

734.8

 

A29

171.3

175.8

298.2

352.5

414.7

984.0

366.9

458.6

984.0

 

A30

133.9

136.8

202.7

255.2

363.0

933.4

363.0

454.6

933.4

 

A31

119.0

120.7

162.2

244.0

362.6

751.7

314.3

500.4

751.7

 

A33

115.7

117.6

154.7

255.5

400.1

1323.9

494.1

566.4

1323.9

 

A34

92.4

93.0

109.3

234.1

341.6

856.6

411.6

892.0

892.0

 

 

* Background concentrations are included.

9.4.3                                The modelling results showed that without dust mitigation, exceedances of the 500mg/m3 1-hour and 260mg/m3 24-hour average TSP standards were found at most of the sensitive receivers.  Highest levels were predicted at A15 (City Hall).  Since exceedance of both TSP guidelines and AQOs are predicted at sensitive receivers, mitigation measures will be required.

9.5                                      Mitigation of Adverse Environmental Impacts

9.5.1                                The predictions included in Tables 9.3 and 9.4 indicate that the construction dust impacts would be significant.  Therefore in order to comply with the 1-hour average TSP guideline level and the 24-hour average TSP AQO, the following mitigation measures are proposed for the CRIII project:

·                strictly limit the truck speed on site to below 10 km per hour and water spraying to keep the haul roads in wet condition;

·                twice daily watering of the work site with active operations when the weather and the work site are dry;

·                watering during excavation and material handling;

·                provision of vehicle wheel and body washing facilities at the exit points of the site, combined with cleaning of public roads where necessary; and

·                tarpaulin covering of all dusty vehicle loads transported to, from and between site locations.

9.5.2                                In addition, the following mitigation measures proposed in WDII and CWB projects are assumed to be implemented by the corresponding parties:

WDII (CWB entrusted work) and WDII (non-CWB entrusted work), managed by TDD

· Strictly limit the truck speed on site to below 10km per hour and water spraying to keep the haul roads in wet condition.  This will reduce the dust generation by about 90%, in accordance with Control Techniques for Particulate Emissions from Stationary Sources, Volume 2, US Environmental Protection Agency 1982.

· Twice daily watering of the work site with active operations when the weather and the work site are dry.    Through the implementation of this mitigation measure, dust emissions from materials handling can be reduced by 50%, according to USEPA AP-42;

· Waterspraying during excavation and material handling; this can reduce the emission by 85%;

· Provision of vehicle wheel and body washing facilities at the exit points of the site, combined with cleaning of public roads where necessary; and

· Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations.

CWB project managed by HyD

· Strictly limit the truck speed on site to below 10 km per hour and waterspraying to keep the haul roads in wet condition;

· Twice daily watering of the work site with active operations when the weather and the work site are dry; 

· Watering during excavation and material handling;

· Provision of vehicle wheel and body washing facilities at the exit points of the site, combined with cleaning of public roads where necessary; and

· Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations.

9.5.3                                With the above mitigation measures, the predicted cumulative 1-hour and 24-hour TSP concentrations are shown in Tables 9.5 and 9.6.   The maximum predicted cumulative 1-hour and 24-hour TSP concentrations within the whole construction period with the above mitigation measures in place at 1.5m above ground level are shown in Figures 9.2 and 9.3.  Detailed breakdown of the dust impacts from different construction activities with mitigation measures in place is shown in Appendix N.

Table 9.5  : Predicted Cumulative 1-hour Average TSP Concentration for Scenarios 1 to 8 (Mitigated)

 

ASRS

Predicted Concentration (mg m -3) under different scenarios

 

 

Scen. 1

Scen. 2

Scen. 3

Scen. 4

Scen. 5

Scen. 6

Scen. 7

Scen. 8

Max.

A6

89.2

88.8

93.8

93.2

130.2

135.5

99.1

167.1

167.1

 

A7

90.0

89.6

96.2

95.2

134.4

140.5

100.8

163.4

163.4

 

A8

91.7

91.3

100.4

98.4

143.7

150.7

103.9

176.0

176.0

 

A9

97.2

97.8

146.9

153.7

173.0

181.0

118.7

185.0

185.0

 

A10

95.9

96.5

155.4

161.4

150.4

155.3

110.2

161.6

161.6

 

A11

100.2

101.0

103.9

110.5

163.0

168.0

114.1

180.0

180.0

 

A12

99.0

99.8

103.1

110.8

154.3

157.4

109.6

167.8

167.8

 

A13

105.7

106.6

105.4

99.3

156.5

164.8

109.1

162.4

164.8

 

A14

113.0

114.4

112.3

101.8

171.2

180.5

112.2

170.6

180.5

 

A15

166.9

171.6

140.3

111.2

341.1

347.7

160.5

257.4

347.7

 

A16

118.3

119.7

115.3

102.9

183.3

192.7

116.1

187.8

192.7

 

A17

116.8

118.6

119.3

104.4

190.8

202.0

114.7

174.8

202.0

 

A18

113.9

116.2

122.8

108.7

210.7

222.6

116.4

158.8

222.6

 

A19

111.4

112.7

121.8

110.1

217.6

227.0

117.3

153.2

227.0

 

A20

225.4

225.7

251.3

132.1

295.8

310.9

135.2

209.2

310.9

 

A21

130.3

132.8

137.2

110.9

271.1

283.4

122.1

180.3

283.4

 

A22

102.6

104.4

110.4

107.5

175.0

195.7

114.7

149.3

195.7

 

A23

99.0

101.9

106.4

103.7

152.1

169.3

108.9

141.0

169.3

 

A24

98.4

100.9

105.2

106.5

133.4

158.8

110.3

142.8

158.8

 

A25

98.4

99.3

108.7

110.4

130.8

175.4

120.0

141.5

175.4

 

A26

102.7

103.3

125.9

117.6

133.9

207.4

132.4

156.7

207.4

 

A27

93.8

94.2

103.6

113.6

137.1

211.8

132.8

174.5

211.8

 

A28

114.7

115.6

132.8

126.6

151.9

211.2

130.7

165.1

211.2

 

A29

107.4

108.2

129.0

135.5

149.6

259.5

150.4

179.2

259.5

 

A30

97.3

97.0

108.2

114.7

137.5

253.0

150.9

176.0

253.0

 

A31

92.8

92.4

99.0

113.7

138.6

217.3

135.4

184.1

217.3

 

A33

93.1

91.4

96.8

117.2

144.5

335.9

184.8

195.0

335.9

 

A34

83.9

84.2

86.1

114.3

131.6

240.0

155.3

262.5

262.5

 

* Background concentrations are included.

Table 9.6  : Predicted Cumulative 24-hour Average TSP Concentration for Scenarios 1 to 8 (Mitigated)

 

ASRS

Predicted Concentration (mg m -3) under different scenarios

 

 

Scen. 1

Scen. 2

Scen. 3

Scen. 4

Scen. 5

Scen. 6

Scen. 7

Scen. 8

Max.

A6

86.6

85.5

89.8

87.6

108.7

112.1

91.3

126.4

126.4

 

A7

87.0

85.9

91.1

88.7

110.9

114.5

92.2

124.5

124.5

 

A8

88.2

86.9

93.6

90.3

116.1

119.9

94.1

131.1

131.1

 

A9

91.4

90.6

118.1

118.1

132.9

136.4

102.3

137.1

137.1

 

A10

90.3

89.9

122.1

122.0

120.3

122.3

97.2

124.4

124.4

 

A11

92.6

92.5

97.1

96.7

127.1

129.1

99.3

133.7

133.7

 

A12

91.8

91.8

96.5

96.9

122.3

123.3

96.9

127.4

127.4

 

A13

95.1

95.7

98.4

91.2

123.2

126.7

96.6

124.8

126.7

 

A14

98.8

100.1

102.6

92.6

130.7

135.1

98.2

129.4

135.1

 

A15

126.6

132.9

122.5

97.6

219.0

221.4

124.0

174.3

221.4

 

A16

101.6

103.2

104.8

93.2

137.2

141.2

100.4

138.7

141.2

 

A17

100.7

102.5

106.6

94.1

140.9

146.6

99.6

131.5

146.6

 

A18

99.2

101.1

108.7

96.4

150.8

157.7

100.5

123.2

157.7

 

A19

97.8

99.2

108.1

97.1

154.2

160.4

101.0

120.2

160.4

 

A20

155.4

164.0

188.7

108.6

197.0

205.2

111.1

148.6

205.2

 

A21

107.6

110.7

117.8

97.5

181.8

188.5

103.7

134.3

188.5

 

A22

93.0

94.4

101.4

96.1

132.4

144.7

99.6

117.7

144.7

 

A23

91.1

93.0

99.2

94.1

120.5

131.1

96.7

113.4

131.1

 

A24

90.6

92.4

98.7

95.7

111.0

126.5

97.5

114.5

126.5

 

A25

90.5

91.5

101.7

98.3

110.1

135.2

102.8

113.8

135.2

 

A26

92.8

93.8

113.5

104.1

113.9

156.3

109.8

122.3

156.3

 

A27

88.1

88.6

98.0

101.7

114.6

156.3

110.1

131.1

156.3

 

A28

99.0

100.8

120.8

107.4

122.5

158.8

108.4

125.9

158.8

 

A29

95.2

96.7

116.5

115.6

124.4

191.3

119.2

133.6

191.3

 

A30

90.0

90.2

101.8

103.8

116.6

180.5

120.1

132.2

180.5

 

A31

87.6

87.5

94.9

101.5

115.1

158.7

111.6

136.4

158.7

 

A32

87.8

87.2

94.6

108.4

123.2

221.9

139.8

142.7

221.9

 

A33

83.2

83.3

87.9

110.1

119.7

170.3

123.4

177.5

177.5

 

* Background concentrations are included.

9.5.4                                From the above results, under the intensive mitigation measures applied in each project, the predicted dust levels at all air sensitive receivers will comply with the 1-hour and 24-hour TSP criteria.

9.5.5                                To further ensure compliance with the AQOs at the ASRs at all time, requirements of the Air Pollution Control (Construction Dust) Regulation shall be adhered to during the construction period.  In addition, good site practices and a comprehensive dust monitoring and audit programme are recommended to minimise cumulative dust impacts.

9.6                                      Potential Odour Impacts from Embayment

9.6.1                                The FEIASO concluded that the locations of the temporary formed water bodies would vary with the reclamation programme, and would, in general be located at least 250m from sensitive receivers. The expedient connection survey undertaken by Atkins Haswell in 1995 indicated that discharges were not heavily polluted, and that due to the distance from receivers, water movement and flushing of the area, that odour strength would be kept to a minimum and odour impact would be limited. The method of reclamation is not significantly different for the Minimum Option, so the conclusion of the FEIASO would be unchanged.

9.7                                      Asbestos

9.7.1                                The FEIASO concluded that an Asbestos Investigation Report should be produced for the structures which will be demolished (notably the Star Ferry Terminal and Queen's Pier, in accordance with the requirements of the Air Pollution Control Ordinance. This conclusion is still valid.

9.7.2                                The only likely source of asbestos is electrical switch boxes, which are not particularly difficult to dispose of safely. Further detailed asbestos survey work is outside the remit of the EIA.

9.8                                      Conclusion

9.8.1                                The major potential air quality impact during the construction phase of CRIII will result from dust arising from various construction activities including excavation works, handling and stockpiling of excavated spoil, vehicle movements on unpaved haul roads, and other general construction works.

9.8.2                                The modelling results showed that with the implementation of practicable mitigation measures, dust levels at sensitive receivers would comply with the 1-hour average total suspended particulates (TSP) guideline and 24-hour average AQOs.

 

 

 


10.                                      Water Quality

10.1                                  Introduction

10.1.1                            This chapter presents an environmental assessment of the potential water and sediment quality impacts associated with the construction phase of the CRIII. The assessment addresses the key issues relating to water quality including the impacts of marine mud dredging and reclamation filling, the discharges of domestic and commercial effluents and cooling waters, and the accumulation of floating debris. The assessment has focused on impacts at the CRIII dredging and filling sites in Victoria Harbour as the environmental impacts associated with marine fill extraction and marine sediment disposal have already been assessed by Civil Engineering Department environmental impact assessment studies.

10.1.2                            As described in Chapter 4 a number of marine (coastal) facilities will be constructed during CRIII including reprovisioned pier (Ferry Pier 8) and public landing steps and a berth for the PLA.  The reprovisioned pier and public landing steps will be “piled deck” structures, while the berth will be an integral part  of the seawall.  As such these facilities will not influence the movement of water and have therefore not been included in the coastline configurations for modelling.

10.1.3                            Additional sewage generated by the development on CRIII (approximately 489 l/s) will be collected in a local sewage gravity pipework system, directed to the CW3 Trunk Sewer and from there to the Wan Chai East screening plant for treatment.  This method of dealing with the flows has been accepted by the DSD and EPD.  DSD have confirmed that sufficient capacity is available within the CW3 Trunk Sewer to cope with the flows from CRIII.  The additional flows will be generated by the occupants of the new Central Government Complex and the proposed commercial buildings as well as the increases brought about by the redevelopment of some of the existing buildings.  The method for dealing with sewage flows described above will not result in any water quality impacts within the CRIII area.  Any impacts will have been assessed under other dedicated Government studies relating to the CW3 Trunk Sewer.

10.2                                  Sensitive Receivers

10.2.1                            In order to evaluate the water quality impacts during the construction phase, the proximity of Water Sensitive Receivers (WSRs) to the work sites must be considered. These have been specified in accordance with the Hong Kong Planning Standards and Guidelines (HKPSG), which provides guidelines for identifying environmental factors influencing development planning.

10.2.2                            Victoria Harbour is ecologically degraded. There are no major biological sensitive receivers such as mariculture zones, commercial fisheries, or shell fisheries  in the vicinity of the study area. Within the study area and the nearby area of Central Reclamation Phase 1 (CRI), there are a number of seawater pumping stations and associated cooling water intakes which supply cooling seawater to the air conditioning systems of a number of commercial buildings in Central. Used cooling water is discharged directly, or, through the stormwater drainage system, into Victoria Harbour. These cooling water intakes and the discharge flows are listed in Table 10.1 and indicated in Figure 2.2 (refer to Chapter 2).

Table 10.1 :  Water Sensitive Receivers (Sea Water Cooling Systems Intakes and Discharges)

Building

Intake number (Refer to Figure 2.2 in Chapter 2)

Discharge

Buildings Directly Affected by CRIII:

 

 

Prince's Building Group: Prince's Building, Alexandra House, Swire House (Also flushing water to Bank of China Building, Hang Chong Building, Holland House and Standard Chartered Bank)*

1

Culvert F

Mandarin Hotel

1

Culvert F

Hongkong and Shanghai Bank

5,6

Culvert H

Murray Road Car Park Group: Murray Road Car Park, Hutchison House and Bank of America Tower

8, 10

Culvert J1

Furama Hotel

11

Culvert J3

Central Government Office: City Hall, LegCo, Murray Building and Central Govt Offices

8, 10

Culvert J1

Central Barracks

12

Culvert J2

Pacific Place

17

Culvert K2

Queensway Government Offices and Supreme Court Building

18

Culvert K1

MTRC South Intake Structure

21

Outfall "MTRC"

Police Headquarters

18

Culvert L

HKAPA

Not Applicable

22

*    The building owner has confirmed that water quality requirements for the intake cover all required uses for the water.

10.2.3                            In addition EPD has requested that additional seawater intakes are considered as water quality sensitive receivers in the assessment. These intakes are as follows:

·                Kennedy Town;

·                Quarry Bay;

·                Sai Wan Ho;

·                Cha Kwo Ling;

·                Yau Tong;

·                Tai Wan

·                Yau Ma Tei; and

·                Cheung Sha Wan.

10.2.4                            There are no water quality objectives for the cooling water intakes specified by Government. Questionnaires were sent to request information regarding the operating condition and criteria of the existing cooling water systems within the CRIII area.  The replies received indicated that there was no particular absolute requirements for intake water quality. Hence, the sensitive receivers within the study area do not have specifications for the quality of the cooling water, although the threshold criteria of SS specified by users of several cooling water intakes (for example, Queen Mary Hospital Intake and Wah Fu Estate Intake) is 140 mgl-1. This level should only be treated as recommended threshold level and could vary according to the requirements of different cooling water users. For the salt water used for flushing, WSD has an SS standard of 10 mgl-1 (with an upper tolerance level of 20 mgl-1). Other WSD standards are ammoniacal nitrogen <1  mgl-1 , DO > 2mgl-1, BOD5 <10 mgl-1, E. Coli < 20,000 /100ml, Colour (H.U.) <20, Turbitity (N.T.U.) <10, Threshold Odour Number <100 and Synthetic Detergents <5 mgl-1.

10.3                                  Existing Conditions

10.3.1                            Water Quality

10.3.1.1            The features of water quality in the study area are largely dominated by tidal currents and flows from the Pearl River Delta. These result in predictable seasonal mixing of this water body. During the wet season, large volumes of fresh water are introduced producing salinity and temperature gradients whereas during the dry season the water column is relatively well mixed and stable as oceanic waters flow in the opposite direction. Maximum water velocities within the Harbour are recorded at 0.7ms-1 while within the study area this is reduced to a minimal 0.1 ms-1.

10.3.1.2            Water quality measurements are taken and recorded by the EPD. Recent data were reported in  Marine Water Quality in Hong Kong 1997. A summary of water quality in the Victoria Harbour Water Control Zone is provided below. Tables 10.2 - 10.5 provide the water quality statistics for 1995 - 1998.

10.3.1.3            Water quality at monitoring stations closer to the sewage outfalls was found to the generally more turbid, richer in inorganic nutrients (total nitrogen and phosphorus) and higher in E, Coli and faecal coliforms.

10.3.1.4            Similar to other WCZs, an increase in total Kjeldahl nitrogen and total nitrogen (0.4-0.7  mgl-1) corresponding to a doubling of the 1996 values was observed in 1997 at all 11 stations in Victoria Harbour. An average increase of 0.02  mgl-1 (0.01 - 0-05  mgl-1) in ammoniacal nitrogen and an increase of 0.06  mgl-1 (0.01-0.07  mgl-1) in total inorganic nitrogen were found at all monitoring stations except those in the Rambler Channel.  The values in 1998 are, however, very similar to the values measured in 1997.

10.3.1.5            In 1997, there was an average increase in silica level by around 0.04  mgl-1 (40% rise). Total phosphorus was found to decline by an average of 0.04  mgl-1 (30% reduction) at all stations. While Chlorophyll-a which indicates algal biomass was found to fall in 1997 , it was observed to increase significantly in 1998.

10.3.1.6            In 1997 there was a substantial increase in the E.coli level at VM6 to almost double the 1996 value but the value was found to reduce to its 1996 level in the 1998 measurements.

10.3.1.7            There was some improvement in dissolved oxygen (DO) in 1997 with full compliance with the WQO (>=2  mgl-1 in 90% of the bottom DO samples and >=4 mgl-1 in 90% of the depth averaged samples) at all stations except VM6. This was the highest compliance rate for the last 10 years.  The improvement was also found to continue in 1998.

10.3.1.8            There was a decrease in the compliance with the inorganic nitrogen objective (<=0.4  mgl-1) during 1997. Only 4 out of the 11 stations met the inorganic nitrogen objective. All stations complied with the unionised ammonia WQO (<=0.021  mgl-1) in 1997,although there was some elevation observed at the majority of locations.  These trends were also repeated in the 1998 measurements. There was a significant long-term increase in temperature of 1.5oC over the past 10 years.

10.3.1.9            It is the long term aim of the HKSAR Government to reduce the level of pollutants within the Harbour. The Strategic Sewage Disposal Scheme (SSDS) initiated in 1989 reflects this commitment.  The original scheme aims to divert output from sewage screening plants around Victoria Harbour and in South West Hong Kong Island and discharge treated sewage to the west of the Harbour in the interim but to the southern waters of the SAR in the long term. The SSDS aims to reduce sewage entering the Harbour with the SSDS Stage 1 currently due for completion in 2001.  Under the Review of SSDS, the International Review Panel in November 2000 has recommended four options for the remaining stages, i.e. Stage II and III / IV, of SSDS with higher level of treatment and different discharge location in the harbour.  The way forward for the remaining stages is currently under consideration by the Administration.  Consequently it is predicted that in the long term current pollutant loads will fall and future baseline water quality will improve.


Table 10.2 :  Summary Statistics of 1998 Water Quality – Victoria Harbour Central

 

Victoria Harbour Central

Determinant

VM4

VM5

VM6

Temperature (°C)

23.7

(17.2 - 32.4)

23.3

(17.1 - 27.8)

23.3

(17.1 - 27.6)

Salinity (ppt)

30.9

(28.1 - 33.5)

30.8

(27.3 - 33.2)

30.6

(26.8 - 33.1)

DO (mg/l)
Surface

 

Bottom

 

4.8
(3.1 – 6.5)

4.4
(2.7 – 6.3)

 

4.8
(3.0 – 6.5)

4.2
(2.8 - 6.4)

 

4.9
(2.9 – 6.8)

4.2
(2.0 – 6.0)

DO (% satn.)
Surface

 

bottom

 

69
(49 – 93)

64
(43 – 80)

 

68
(45 - 97)

59
(41 - 80)

 

70
(46 - 99)

59
(29 – 75)

pH value

7.9
(7.4 – 8.2)

7.5
(6.6 - 8.1)

7.8
(7.2 – 8.2)

Secchi Disc (m)

2.5
(1.8 – 3.5)

2.2
(1.7 – 3.0)

2.2
(1.0 – 3.0)

Turbidity (NTU)

4.3

(2.9 – 6.7)

4.5
(3.1 – 5.9)

4.4
(2.8 – 6.1)

Suspended Solids (mg/l)

4.6
(2.6 – 10.5)

4.6
(2.2 – 8.0)

4.7
(1.9 – 7.6)

BOD5 (mg/l)

1.0
(0.7 – 1.4)

1.2
(0.5 – 2.3)

1.2
(0.5 – 1.8)

Total Inorganic N (mg/l)

0.43
(0.23 – 0.72)

0.45
(0.21 - 0.72)

0.44
(0.24 – 0.67)

Total N (mg/l)

1.23
(0.96 – 1.54)

1.22
(0.98 - 1.58)

1.21
(0.93 – 1.52)

PO4 -P (mg/l)

0.05
(0.02 – 0.08)

0.05
(0.01 - 0.08)

0.05
(0.02 – 0.07)

Total P (mg/l)

0.09

(0.07 – 0.11)

0.09

(0.06 - 0.12)

0.09
(0.07 – 0.11)

Chlorophyll-a (µg/l)

4.8
(0.9 – 19.1)

4.7
(0.6 – 21.7)

4.9
(0.6 – 24.0)

E. coli (cfu./100ml)

8400

(910 - 82000)

7200
(570 – 33000)

5100
(1400 - 12000)

 

 

 

Table 10.3 :  Summary Statistics of 1997 Water Quality – Victoria Harbour Central

 

Victoria Harbour Central

Determinant

VM4

VM5

VM6

Temperature (°C)

23.1
(16.6 – 27.6)

23.1
(16.7 - 27.6)

23.1
(16.8 – 27.5)

Salinity (ppt)

30.6
(27.1 – 32.8)

30.5
(26.1 - 32.7)

30.4
(25.1- 32.7)

DO (mg/l)
Surface

 

Bottom

 

4.7
(3.6 – 6.4)

4.4
(3.2 – 6.7)

 

4.7
(3.6 – 5.4)

4.2
(3.0 - 5.6)

 

4.7
(3.8 – 6.0)

4.3
(2.3 – 5.9)

DO (% satn.)
Surface

 

bottom

 

66
(54 – 85)

61
(48 – 88)

 

66
(52 - 78)

58
(42 - 73)

 

66
(53 - 88)

60
(32 – 77)

pH value

8.0
(7.5 – 8.2)

7.6
(6.7 - 8.1)

7.8
(7.1 – 8.1)

Secchi Disc (m)

2.5
(1.2 – 4.5)

2.2
(1.5 – 4.0)

2.2
(1.0 – 4.0)

Turbidity (NTU)

4.0
(1.9 – 8.8)

4.3
(1.5 – 7.2)

4.1
(1.7 – 7.2)

Suspended Solids (mg/l)

5.7
(2.0 – 19.7)

6.4
(1.6 – 13.3)

6.6
(1.8 – 14.3)

BOD5 (mg/l)

0.8
(0.4 – 1.7)

0.8
(0.4 – 1.6)

0.8
(0.4 – 2.0)

Total Inorganic N (mg/l)

0.40
(0.24 – 0.57)

0.40
(0.25 - 0.53)

0.42
(0.253 – 0.551)

Total N (mg/l)

1.23
(0.36 – 1.64)

1.20
(0.51 - 1.64)

1.22
(0.52 – 1.60)

PO4 -P (mg/l)

0.05
(0.03 – 0.08)

0.05
(0.02 - 0.08)

0.05
(0.03 – 0.09)

Total P (mg/l)

0.10
(0.06 – 0.18)

0.11
(0.06 - 0.22)

0.11
(0.06 – 0.20)

Chlorophyll a (µg/l)

1.8
(0.7 – 5.6)

1.4
(0.4 – 4.2)

1.3
(0.5 – 3.1)

E. coli (cfu./100ml)

8159
(3567 – 19000)

7494
(2400 – 22733)

10600
(3333 - 45333)

 

 

 


Table 10.4 :  Summary Statistics of 1996 Water Quality – Victoria Harbour Central

 

Victoria Harbour Central

Determinant

VM4

VM5

VM6

Temperature(°C) Surface Bottom

 

23.3
(18.9 – 27.8)

22.8
(18.8 – 27.8)

 

23.6
(19.1 – 28.3)

23.3
(18.9 – 29.0)

 

23.3
(18.9 – 28.0)

22.9
(18.9 – 27.7)

Salinity (ppt) Surface Bottom

 

31.8
(27.0 – 34.0)

32.8
(30.5 – 34.2)

 

31.4
(26.6 – 33.9)

32.1
(30.0 – 34.2)

 

31.6
(26.4 – 34.0)

32.4
(30.1 – 34.1)

DO (% satn.) Surface Bottom

 

69.1
(46.9 – 108.0)

60.4
(30.3 – 73.0)

 

69.4
(50.3 – 104.0)

64.2
(47.9 – 90.6)

 

76.1
(45.2 – 111.9)

62.3
(38.8 – 86.9)

DO (mg/l) Surface Bottom

 

4.9
(3.5 – 7.3)

4.3
(2.1 – 5.4)

 

4.9
(3.8 – 7.0)

4.5
(3.3 – 6.1)

 

5.4
(3.4 – 7.7)

4.4
(2.7 – 5.9)

pH value

7.9
(7.7 – 8.1)

7.9
(7.7 – 8.1)

7.9
(7.7 – 8.1)

Secchi Disc (m)

2.0
(1.2 – 2.7)

1.9
(1.2 – 2.8)

1.8
(1.2 – 3.0)

Turbidity (NTU)

3.9
(1.8 – 8.6)

4.1
(2.1 – 7.8)

4.2
(2.2 – 7.8)

Suspended Solids (mg/l)

7.5
(3.8 – 16.7)

8.3
(3.5 – 15.3)

8.9
(3.1 – 15.7)

BOD5 (mg/l)

0.8
(0.5 – 1.4)

0.9
(0.6 – 1.4)

0.8
(0.5 – 1.3)

Total Inorganic N (mg/l)

0.33
(0.17 – 0.49)

0.36
(0.17 – 0.57)

0.36
(0.14 – 0.54)

Total N (mg/l)

0.62
(0.34 – 0.92)

0.65
(0.37 – 0.93)

0.67
(0.38 – 0.93)

PO4 -P (mg/l)

0.05
(0.02 – 0.06)

0.05
(0.02 – 0.08)

0.05
(0.02 – 0.08)

Total P (mg/l)

0.18
(0.09 – 0.41)

0.16
(0.10 – 0.25)

0.16
(0.07 – 0.26)

Chlorophyll a (µg/l)

1.92
(0.53 – 6.13)

1.97
(0.50 – 7.07)

1.80
(0.53 – 7.17)

E. coli (cfu./100ml)

7785
(2133 – 18333)

11373
(4753 – 23667)

5698
(773 – 14667)

 

Table 10.5 :  Summary Statistics of 1995 Water Quality – Victoria Harbour Central

 

Victoria Harbour Central

Determinant

VM4

VM5

VM6

Temperature(°C) Surface Bottom

 

22.8
(15.7 – 29.0)

22.2
(15.6 – 28.4)

 

22.8
(15.7 – 29.0)

22.1
(15.7 – 28.4)

 

2.8
(15.8 – 29.1)

22.2
(15.7 – 28.4)

Salinity (ppt) Surface Bottom

 

30.5
(19.6 – 33.3)

32.2
(29.4 – 33.8)

 

30.3
(19.4 – 33.2)

32.2
(29.6 – 33.7)

 

30.2
(19.1 – 33.2)

32.2
(29.4 – 33.5)

DO (% satn.) Surface Bottom

 

73.0
(46.7 – 111.2)

60.9
(31.1 – 86.6)

 

76.6
(52.6 – 111.7)

62.1
(35.1 – 78.7)

 

72.6
(39.7 – 103.4)

60.1
(35.9 – 79.5)

DO (mg/l) Surface Bottom

 

5.2
(3.5 – 7.5)

4.4
(2.3 – 6.5)

 

5.5
(3.9 – 7.5)

4.5
(2.6 – 6.3)

 

5.2
(3.0 – 7.1)

44
(2.5 – 6.1)

pH value

8.0
(7.8 – 8.2)

8.0
(7.8 – 8.1)

8.0
(7.8 – 8.1)

Secchi Disc (m)

1.6
(1.0 – 2.2)

1.6
(0.9 – 2.1)

1.5
(1.0 – 2.0)

Turbidity (NTU)

4.5
(2.2 – 7.3)

5.3
(2.8 – 11.3)

5.5
(2.8 – 12.8)

Suspended Solids (mg/l)

10.7
(4.4 – 23.7)

12.1
(5.5 – 30.0)

12.4
(6.0 – 22.3)

BOD5 (mg/l)

0.8
(0.5 – 1.7)

0.8
(0.5 – 1.4)

0.9
(0.4 – 1.7)

Total Inorganic N (mg/l)

0.39
(0.16 – 0.60)

0.40
(0.25 – 0.61)

0.42
(0.23 – 0.62)

Total N (mg/l)

0.66
(0.27 – 0.83)

0.68
(0.45 – 0.98)

0.71
(0.45 – 0.99)

PO4 -P (mg/l)

0.05
(0.03 – 0.09)

0.06
(0.04 – 0.09)

0.05
(0.02 – 0.08)

Total P (mg/l)

0.13
(0.07 – 0.42)

0.13
(0.07 – 0.37)

0.12
(0.05 – 0.37)

Chlorophyll a (µg/l)

2.49
(0.40 – 15.77)

2.18
(0.23 – 12.87)

3.21
(0.37 – 23.67)

E. coli (cfu./100ml)

8033
(2967 – 25800)

6670
(1600 – 14567)

7444
(2633 - 16667)

Notes:     1. Except as specified, data presented are depth-average data.

               2.    Data presented are annual arithmetic means except for E. coli data which are annual geometric means.

               3. Data enclosed in brackets indicate the ranges.

Source:          Marine Water Quality in Hong Kong 1995/6/7

10.3.2                            Circulation and Mixing

10.3.2.1            The hydrodynamic characteristics of the study area are determined to a large extent by the influence of tidal currents and flows from the Pearl River Delta. During the ebb tide water flows down through the Urmston Road and into Victoria Harbour. This flow pattern reverses during the flood tides. These circulation patterns cause predictable seasonal patterns in water mixing as indicated in Figure 4.1 in
Appendix O. During the wet summer season a large influx of freshwater, from the Pearl River catchment and freshwater discharges in the study area, results in salinity and temperature gradients within the water column. The warmer brackish water is located above cooler more saline waters. During the dry winter months the water column is well mixed as oceanic waters move northwards into the Pearl River estuary. Within the study area the water velocities are generally low (of the order of 0.1 ms-1), shorewards of the proposed reclamation limit, although water velocities in the main harbour channel can reach 0.6-0.7 ms-1.

10.4                                  Baseline Water Quality Modelling

10.4.1                            Introduction

10.4.1.1            Baseline modelling was undertaken to determine the conditions against which the impacts of construction and operation of the CRIII could be evaluated and is described in this section.

10.4.2                            Mathematical Models

10.4.2.1            Hydrodynamic Model, TELEMAC-3D

10.4.2.1.1                TELEMAC-3D is a finite element hydrodynamic modelling system for simulating physical processes associated with rivers, estuaries and coastal waters. TELEMAC-3D is based on a horizontal mesh of triangles with sigma-based, vertically spaced nodes.  At each node of the finite element mesh, the water depth, horizontal and vertical velocity components, temperature and salinity are computed by a first order solution of the equations for conservation of water mass, momentum and tracers.
10.4.2.1.2                For Hong Kong coastal waters, the three-dimensional solution has five nodes, equally spaced in the vertical direction:  at the bed, the surface and three intermediate levels.  The triangular finite element mesh was fitted to the projected coastline using a minimum element size of about 20m.  The density of the mesh varied continuously within the model area, from a coarse grid in the outer areas, to a fine grid in the areas where the bathymetry, reclamation, hydrodynamics and water quality needed to be resolved most accurately.
10.4.2.1.3                Boundary conditions for the Hong Kong coastal waters model consist of tidal conditions along the offshore boundary and discharges from the Pearl River.

10.4.2.2            Water Quality Model, TELEMAC-3D-WQ

10.4.2.2.1                TELEMAC-3D-WQ is an advection/dispersion based finite element water quality model, which simulates multiple constituents and interactions.  It is run in parallel with the TELEMAC-3D hydrodynamic model, and is based on the same finite element mesh. Water quality variables used in the Hong Kong coastal waters model are:

·                Fast and slow dissolved BOD

·                Fast and slow particulate BOD

·                Fast and slow organic nitrogen

·                Ammoniacal  nitrogen1

·                Nitrite

·                Nitrate

·                Orthophosphate

·                Dissolved oxygen

·                Suspended sediment

·                Algal carbon and Chlorophyll-a

·                Detrital carbon

·                Coliforms

Calculation of unionised ammonia from ammoniacal nitrogen follows the methodology in "Rates, constants and kinetics formulation in surface water modelling", Report EPA/600/3-85/040, USEPA, Jun 1985.

10.4.2.2.2                All constituents were solved at the nodes of the three dimensional finite element mesh.  Additional variables representing particulate BOD, sediments, algal carbon and detrital carbon on the sea bed are also included. 
10.4.2.2.3                Concentrations of water quality constituents are set at appropriate nodes to represent internal loads, such as outfalls and nullahs, and at boundary nodes to represent oceanic conditions or river inflows.  Advection and diffusion of the water quality constituents is driven by the hydrodynamic solution, which moves constituent concentrations between nodes.  Water quality interactions between variables are calculated at each node of the domain.
10.4.2.2.4                The decay of organic materials and the nitrification of ammoniacal nitrogen are expressed by first order kinetics, whereby the rate of change of a substance due to decay is given by dC/dt = K.C, where K is the reaction rate constant.  The reaction rate constants are functions of temperature.

10.4.2.3            Sediment Plume Model – SEDPLUME-RW(3D)

10.4.2.3.1                SEDPLUME-RW(3D) is a three-dimensional suspended mud dispersal model for simulating the transport, dispersion, settling, deposition and re-suspension of mud grains released into the water column during dredging.  Suspended mud advection by mean tidal currents is based on flows simulated by TELEMAC-3D, and turbulent dispersion is represented using a well-established random walk (Lagrangian) technique.
10.4.2.3.2                Suspended mud released into the water column is represented by regularly released discrete particles, with each particle representing a defined quantity of sediment.  Particles move under the influence of prevailing mean flows, turbulent dispersion and gravitational settling.  Settling rates are computed using settling velocities, which can be derived from the calculated suspended mud concentrations.  When model particles impact on the sea bed, they remain stationary at their point of impact if the prevailing bed shear stress associated with the mean flow is sufficiently low for mud deposition to occur.  If the stress increases subsequently to the point where it exceeds the erosional shear strength of the mud deposits, then particles may re-enter the flow field, at rates depending on the excess shear stress and an erosion constant.
10.4.2.3.3                Suspended mud concentrations are computed in SEDPLUME-RW(3D) at regular intervals through a simulation.  Concentrations are calculated on a structured mesh of square elements, an element dimension of 40m was chosen for the EIA Study in order to resolve the main features of relatively narrow suspended mud plumes and the coastline in the Central area.  Vertically, the model is divided into layers, separated by the planes of the TELEMAC-3D model.  When calculating concentrations, the mud represented by all the suspended particles in each layer of each element of the SEDPLUME-RW(3D) mesh is summed, and divided by the element volume to derive a layer-averaged suspended mud concentration.
10.4.2.3.4                Mud deposits are calculated in a similar way to suspended mud concentrations.  The mud represented by all the model particles on the sea bed in each element of the output mesh is summed, and divided by the cell area to provide a deposits distribution (kg.m-2).

10.4.2.4            Model Calibration

10.4.2.4.1                Calibration of the hydrodynamic model was carried out during a previous study, as four exercises representing spring and neap tide conditions in both the dry and wet seasons.  The water quality model was calibrated for spring-neap cycles in both seasons.
10.4.2.4.2                Calibration of the hydrodynamic model was achieved using water level, current and salinity measurements made in 1990 at stations throughout the inner regions of the Hong Kong coastal waters. The calibration included a measurement point in Victoria Harbour (E5), around 3km east of the planned Central reclamations.
10.4.2.4.3                The hydrodynamic model was calibrated by adjusting the bed friction, eddy viscosity, turbulent diffusion coefficient and Pearl River discharges.  Agreement between the model and observations was optimised at all stations in terms of pre-defined criteria relating to:  tidal elevation, phase difference of tidal elevations, current speed deviation, current speed phase difference, current direction and salinity values.   The target accuracies used are summarised in Table 10.6

Table 10.6 :  Target Accuracies Used for the Calibration of the Hydrodynamic Model

Hydrodynamic variable

Target accuracy

Tidal elevation

Within 8%

Tidal phase

Within 20 minutes

Current speed

Within 30% for speeds greater than 0.3m/s

Current phase

Within 20 minutes

10.4.2.4.4                The dry season simulations gave extremely good representations of the tidal levels and tidal propagation over the area of the measurements.  The representation of tidal propagation further into the Pearl River estuary was unclear due to lack of data.  Modelled currents were particularly good at the Central measurement sites, whilst agreement between the model results and data was somewhat poorer in the western waters, but maintained a high numerical "goodness" of fit.
10.4.2.4.5                The wet season simulations also gave good representations of the tidal levels and propagation.  The stratification, density driven flow and multi-layered flow caused by the greater volume of fresh water from the Pearl River combine to make calibration more difficult.  As expected, there was generally less agreement between modelled and observed currents than for the dry season.  Nevertheless, the model reproduced most of the features of the complex 3D flow well, including differences in surface and bed flood and ebb currents and salinity profiles.
10.4.2.4.6                In general, the hydrodynamic model results at Station E5, in Victoria Harbour, were within or near the calibration targets.  Some current speed differences at specific depths in the water column did not meet the 30% target, but all of the depth-averaged values complied.  This was also the case for the current phases.  Simulated flow directions at E5 also did not comply with the calibration targets at some depths.  In the wet season, however, the depth-averaged flow directions met the calibration targets, and non-compliance was only marginal for the depth-averaged dry season values.
10.4.2.4.7                The aim of the water quality calibration was to reproduce with the model results any identifiable trends and variations in water quality, whilst also being able to qualitatively explain all simulated water quality predictions.  No strict numerical criteria were imposed for calibration of the water quality model, although desired accuracies of pollutant concentrations simulated within a factor of two, and dissolved oxygen within 15% of saturation were set.
10.4.2.4.8                Receiving water quality measurements for calibration were available from three sources:

·                in-situ depth profiles of temperature, dissolved oxygen, salinity and turbidity at selected monitoring stations for the same periods as the hydrodynamic data collection;

·                laboratory determined water quality values obtained from hourly samples compounded over five hour periods at the same monitoring stations; and

·                EPD data collected as spot samples at three depths at several locations over Hong Kong waters (not simultaneous with the other data).

10.4.2.4.9                Calibration of the water quality model was difficult with the limited amount of information available to define pollutant loads, boundary data and the observed water quality.  The calibration was based on values adopted in the earlier extended WAHMO study, and on sensitivity tests carried out using a two-dimensional model.  The final values adopted for the model parameters are summarised in Table 10.7.

Table 10.7 :  Values of the water quality parameters in the calibration

Model parameter

Value

Fast BOD decay rate (d-1)

0.23

Fast organic nitrogen reaction rate (d-1)

0.23

Nitrification rate (d-1)

0.26

Denitrification rate (d-1)

0.20

Nitrite oxidation rate (d-1)

0.90

Detrital carbon reaction rate (d-1)

0.046

Reaeration rate (m.h-1)

0.2

Erosion rate (kg.N-1.s-1)

0.0005

Slow to fast BOD reaction rate ratio

0.2

Slow to fast organic nitrogen reaction rate ratio

0.2

Nitrate to carbon ratio in algae

0.16

Phosphorus to carbon ratio in algae

0.024

Silicon to carbon ratio in algae

0.0

Chlorophyll to carbon ratio in algae

0.02

Deaeration ratio

0.5

Algae light extinction coefficient

1.70

Maximum respiration rate (d-1)

0.02

Half saturation constant for nitrate ( mgl-1)

0.1

Half saturation constant for phosphate ( mgl-1)

0.014

Half saturation constant for silica ( mgl-1)

0.0

Mortality rate for algae (d-1)

0.35

T90 for coliforms (h)

12

Critical stress for deposition (N.m-2)

0.1

Critical stress for erosion (N.m-2)

0.3

Mud settling velocity (m.s-1)

0.001

Algae settling velocity (m.s-1)

0.00001

Detritus settling velocity (m.s-1)

0.001

10.4.2.4.10            Generally, acceptable results were achieved for all the main water quality parameters, in terms of reproduction of observed trends and the ability to explain model predictions.  Some 65% of the comparisons made between the model and observations at Station E5 met the desired level of accuracy. Differences between the model and observations at this station were considered to be acceptable, given the uncertainties in pollutant loads and water quality measurements.
10.4.2.4.11            The hydrodynamic and water quality model calibrations were accepted by EPD for the parts of Hong Kong coastal waters considered for the previous studies.  The calibrated models were applied in the present study, without further changes to the model parameters.

10.4.3                            Baseline Layout

10.4.3.1            In order to establish baseline conditions for flow and water quality, against which predicted conditions during and following the CRIII works could be judged, the model was run to simulate pre-construction conditions. During previous studies, model meshes had been established for projected coastlines in 2001, 2006 and 2011.  The Baseline reclamation at Central were included in the 2006 coastline, and the model was run for both dry and wet season conditions.

10.4.3.2            Previously, the Hong Kong coastal waters model included minimum element dimensions of around 40m near Green Island, but used coarser resolution elsewhere, including Victoria Harbour.  For the CRIII study, it was necessary to use element dimensions of around 20m near Central, in order to resolve the details of the planned reclamation.  When the model was re-gridded to include smaller elements around the Central reclamation, the sizes of the elements in the Green Island area were increased, in order to provide the required resolution at Central whilst maintaining reasonably practical model run times.  The model mesh in the study area employed for the Baseline simulations is illustrated in Figure 1.1 in Appendix O.  The mesh refinement was designed so that, when proceeding from the Baseline to the later layouts, it was only necessary to alter the model mesh in the immediate vicinity of the reclamations added in each case.

10.4.3.3            The Hong Kong coastal waters model is based on a bathymetric data set on a 100m square grid, set up during previous modelling, and has been enhanced with detailed bathymetric data around planned developments near Green Island.  For the present study, a contoured gridded sounding plan of the Central area, on a 10m square grid (Reference 1) was provided.  These data were incorporated in the model’s bathymetric data set, together with sea bed depths throughout the remainder of Victoria Harbour from Admiralty Chart 3279 (June 1998 edition).

10.4.3.4            Boundary conditions for the CRIII study consisted of water surface level variations at the seaward boundaries of the model and freshwater discharges from the Pearl River.  The discharges were the same as those used in the model for previous Hong Kong studies, with separate values for the dry and wet seasons.  Water levels were also applied as in previous studies, with the synthesis used to derive the previously-applied levels for parts of single spring-neap cycles being extended into the two subsequent spring-neap cycles in each season, as described in more detail below.

10.4.3.5            Previously, the flow and water quality models had been run for approximately 10.4 days in the dry season and 13.3 days in the wet season; these being the periods required to cover an initial five-day run-in period, a spring tide and a neap tide, including the part of the spring-neap cycle between the spring and neap tides.  The runs were terminated on completion of the neap tide, and the analyses were based on the representative spring and neap tides.  For the CRIII study, the simulations were effectively given longer run-in periods than the previous simulations, by taking initial conditions from the ends of the appropriate simulations during the earlier studies, interpolated onto the new CRIII mesh.  The adopted run procedure provided a smooth continuation; that is, the tidal sequences of the previous runs were continued into the new simulations.  Details of the runs are given in Table 10.8, which demonstrates that the CRIII simulations end on spring tides.  Spring and neap tides were selected for analysis from the spring-neap cycles which began approximately 25 days and 27 days after the start of the previous simulations in the dry and wet seasons respectively.

Table 10.8 :  Timing of analysis tides within tidal sequences

 

Season

 

Tide

Tide start time (days from start of simulation)

Previous studies

CRIII - From start of previous studies

From start of CRIII

Dry

 

Spring

5.00

30.79

20.37

Neap

9.38

24.92

14.50

Wet

Spring

5.00

32.88

19.63

Neap

12.21

27.00

13.75

10.4.4                            Water Movement

10.4.4.1            Figures 1.2a and 1.2b in Appendix O show the simulated surface flow patterns in the study area for spring and neap tides in the wet season.  Contour plots of simulated maximum speeds for the same tides at the sea surface and sea bed are shown in Figures 1.3a and 1.3b in Appendix O.  Equivalent results for the dry season are shown in Figures 1.4a – 1.4b and 1.5a – 1.5b in Appendix O.  The Figures demonstrate that the highest current speeds in the study area occur between the Hong Kong Convention and Exhibition Centre (HKCEC) and the Kowloon peninsula.  Some flow occurs through the partial embayment formed by the Central Phase I reclamation and the HKCEC Extension, due to the presence of the channel between the HKCEC Extension and Hong Kong Island, but current speeds are low in this area.

10.4.4.2            In some areas, current speeds on neap tides can exceed those on spring tides, because the spatial distributions of the flows are different for the different tide types, and current speeds are not simply related to tidal ranges.  This is evident from the processed current speed data at Station E5 (Victoria Harbour).  The observed current speed maximum are consistently similar on spring and neap tides in each season, despite the larger tidal range on the spring tide.

10.4.5                            Water Quality

10.4.5.1            Pollutant Loads

10.4.5.1.1                The major contributors to the water quality in Hong Kong waters are pollution loads and the Pearl River.  The majority of the pollution load data for 2006, used in the Baseline simulations, has been obtained from estimates made in a Draft Technical Note, published by Montgomery Watson on behalf of the Environmental Protection Department (Reference 2).  The loads into the Pearl Estuary were taken from an earlier ERL report (Reference 3).  There are three types of discharges :

·                Deep outfalls;

·                Rivers and nullahs; and

·                Storm drains.

The pollution loads of the deep outfalls, storm drains, rivers and nullahs are listed in Table 10.9.  Near Central, the more detailed distribution of loadings shown in Tables 10.10 and 10.11 was used. 

10.4.5.1.2                The estimates of the loads are subject to uncertainties.  The total estimated BOD load into the southern waters of Hong Kong (excluding Deep Bay, Tolo Harbour and Pearl loads) is equivalent of approximately seven million people, based on an average load of 60g/d per person, and may be over-estimated.  No information was given on the proportion of particulate to dissolved BOD or the oxidisation rates of the BOD fractions.
10.4.5.1.3                The discharge of freshwater and flux of pollutants into the head of the Pearl Estuary were defined on the basis of sparse historical data (Reference 4) and experience in calibrating the 3DSL seasonal salinity and water quality models, which included the Pearl Estuary, for the 1988 WAHMO study (Reference 5) and for the 1992 Extended WAHMO study (Reference 6).  The 3DSL model showed that there was a good correlation between the antecedent monthly freshwater flow into the Pearl Estuary and the observed surface salinity north of Lantau.  The first estimate of the pollutant load of the Pearl River in the 1992 model study (Reference 6) was based on sparse reports on the water quality of the Pearl River at Guangzhou (Reference 7).  The Pearl River pollution loads were adjusted to calibrate the 1990 TELEMAC-3D water quality model by reference to observed water quality at site W3 high up in the Pearl Estuary (Reference 6).  The prescribed flows and pollution concentrations and loads from the Pearl River in 1990 used in the TELEMAC-3D model were as summarised in Table 10.9.
10.4.5.1.4                The existing Wan Chai East and Wan Chai West Sewage Screening Plants each have their own submarine outfall.  According to the original SMP programme, the sewerage flow from the Wan Chai West Sewage Screening Plant will have been diverted to the Wan Chai East Sewage Screening Plant by 2006 – the year used for determination of pollution load data.  Therefore, according to the best available information at the time of water quality modelling, the outfall at the Wan Chai East Sewage Screening Plant will be discharging the combined flows from the two screening plants.  Since the time of modelling, Government has confirmed that the Wan Chai West Screening Plant will be de-commissioned in 2003.

Table 10.9 :  Discharges and pollutant loads of the outfalls and stormdrains assumed in the modelling, excluding pollutant sources near CRIII

Location name

Volume m3/day

SS

kg/day

BOD5

kg/day

TKN

kg/day

NH3-N

kg/day

Nitrate

Kg/day

DO

kg/

day

Ecoli

counts/

day

Ortho-P

kg/day

TP

kg/

day

Outfalls

Central

136633

27190.0

34294.9

4918.8

2732.7

0.0

0.0

2.17E+16

382.6

683.2

Cheung Chau

3753

341.5

563.0

78.8

75.1

0.0

0.0

1.69E+14

3.8

6.8

Eastern

71304

14617.3

16613.8

2852.2

1640.0

0.0

0.0

1.35E+16

199.7

356.5

Lamma_PS STW

216

3.5

0.6

0.1

0.1

0.0

0.0

6.91E+06

0.0

0.0

Pillar Point

129652

14132.1

22689.1

5471.3

3422.8

0.0

0.0

1.27E+16

132.2

236.0

Sai Kung

7580

333.5

174.3

153.1

40.2

53.1

0.0

7.58E+10

12.3

21.8

Sha Tau Kok

2577

118.5

64.4

52.3

13.4

38.7

0.0

2.58E+10

4.2

7.4

Sham Tseng

7230

173.5

621.8

240.8

144.6

0.0

0.0

7.23E+07

11.6

20.8

Shek O

1868

358.7

381.1

74.5

43.7

0.0

0.0

3.75E+14

5.0

9.0

Shek Wu Hui

97717

4690.4

2540.6

2032.5

195.4

684.0

0.0

9.77E+11

158.3

281.4

Siu Ho Wan

113843

11270.5

19011.8

4360.2

2732.2

0.0

0.0

1.02E+16

113.8

207.2

Sok Kwu Wan

116

3.5

2.3

0.2

0.1

1.6

0.0

1.16E+09

0.2

0.3

Southern

52000

14196.0

15288.0

2756.0

1508.0

0.0

0.0

1.26E+16

145.6

260.0

SSDS Stage 1

1123600

58427.2

128090.4

39326.0

24719.2

0.0

0.0

1.09E+17

1258.4

2247.2

Stanley

2522

95.8

50.4

45.1

11.9

20.2

0.0

2.52E+10

4.0

7.3

Tai Po Sha Tin

177410

5322.3

3548.2

354.8

443.5

1596.7

0.0

8.87E+12

283.9

510.9

Urmston Road

160976

11751.2

19317.1

4684.4

2962.0

0.0

0.0

1.12E+16

164.2

293.0

Wanchai

109500

22557.0

27484.5

4161.0

2299.5

0.0

0.0

1.91E+16

306.6

547.5

Yung Shue Wan

801

24.0

16.0

1.6

0.8

11.2

0.0

1.48E+13

1.3

2.3

Rivers and Stormdrains

Angler River

2330

0.9

0.7

0.2

0.0

8.6

18.6

5.13E+10

0.6

1.1

Central & Western

31758

6319.8

7971.3

1143.3

635.2

0.0

158.8

5.05E+15

88.9

158.8

Cheung Chau

938

205.4

219.5

41.8

24.5

0.0

4.7

2.09E+14

1.7

3.0

Eastern (CW SKW)

9708

2135.8

2359.0

416.5

235.9

0.0

48.5

1.95E+15

17.5

31.1

Eastern (N.Point Q.Bay)

17826

3654.3

4153.5

713.0

410.0

0.0

89.1

3.39E+15

49.9

89.1

Fanling Shek Wu Hui

20572

4916.7

5307.6

946.3

534.9

0.0

102.9

4.42E+15

37.0

53.5

Kowloon City

17776

3946.3

4426.2

746.6

417.7

0.0

88.9

3.41E+15

32.0

56.9

Kwai Chung

10173

3001.0

3275.7

518.8

262.5

0.0

50.9

1.91E+15

18.3

32.6

Kwun Tong

21909

5543.0

6156.4

1014.4

545.5

0.0

109.5

4.27E+15

39.4

70.1

Mong Kok

7497

1596.9

1911.7

284.9

154.4

0.0

37.5

1.21E+15

13.5

24.0

Mui Wo River

8550

77.0

14.5

3.4

0.9

2.6

68.4

2.75E+11

0.7

1.2

Sai Kung

798

174.8

184.3

35.9

20.7

0.0

4.0

1.79E+14

1.4

2.1

Sha Tau Kok

332

76.0

82.7

14.9

8.6

0.0

1.7

7.17E+13

0.6

0.9

 

 

 


Table 10.9:  Discharges and pollutant loads of the outfalls and stormdrains assumed in the modelling, excluding pollutant sources near CRIII (Cont’d)

Location name

Volume m3/day

SS

kg/day

BOD5

kg/day

TKN

kg/day

NH3-N

kg/day

Nitrate

Kg/day

DO

kg/

day

Ecoli

counts/

day

Ortho-P

kg/day

TP

kg/

day

 

Sham Shui Po

13661

3524.5

3907.0

633.9

336.1

0.0

68.3

2.60E+15

24.6

43.7

Sham Tseng

1320

158.4

283.8

51.7

29.3

0.0

6.6

4.32E+07

2.4

4.2

Shek O

467

89.7

95.3

18.6

10.9

0.0

2.3

9.39E+13

0.8

1.5

Siu Ho Wan

3595

794.5

884.4

153.1

86.3

0.0

18.0

7.12E+14

6.5

11.5

Sok Kwu Wan

12

2.6

2.8

0.5

0.3

0.0

0.1

2.68E+12

0.0

0.0

Southern

13001

3549.3

3822.3

689.1

377.0

0.0

65.0

3.15E+15

36.4

65.0

Stanley

630

121.0

128.5

25.1

14.7

0.0

3.2

1.27E+14

1.1

2.0

Stanley Stream

2450

291.6

1.0

0.0

0.0

4.7

19.6

7.89E+10

0.1

0.3

Tai Po Sha Tin

28141

6416.1

6922.7

1246.6

700.7

0.0

140.7

5.80E+15

50.7

90.1

Tseung Kwan O + SENT

13882

2818.0

2997.1

567.8

327.6

0.0

69.4

2.78E+15

25.0

44.4

Tsing Yi

4012

1043.1

1119.3

203.8

114.7

0.0

20.1

9.43E+14

7.2

12.8

Tsuen Wan

9336

2184.6

2455.4

397.7

214.7

0.0

46.7

1.69E+15

16.8

29.9

Tuen Mun Mullah

13648

3316.5

3521.2

641.5

354.8

0.0

68.2

2.96E+15

24.6

22.5

Urmston Road

33721

5496.5

5968.6

1092.6

623.8

0.0

168.6

5.23E+15

60.7

55.6

Wan Chai

12850

2647.1

3225.4

488.3

269.9

0.0

64.3

2.24E+15

36.0

64.3

Wong Tai Sin

11783

2592.3

2827.9

498.4

275.7

0.0

58.9

2.13E+15

21.2

37.7


Yau Ma Tei

8112

1687.3

2117.2

303.4

169.5

0.0

40.6

1.31E+15

14.6

26.0


Yung Shue Wan

84

18.4

19.7

3.7

2.2

0.0

0.4

1.87E+13

0.2

0.3

*           Loadings have been adopted for all modelling scenarios.

Note:       Discharge and Pollutant Load below relate to the Pearl River Delta

Property

Unit

Value

Dry season

Wet season

Discharge

m3s-1

1,700

10,000

Slow dissolved BOD5

Ppm

tonnes/day

7

Approx. 1,000

1.2

Approx. 1,000

Ammoniacal nitrogen

ppm

tonnes/day

1

Approx. 150

0.3

Approx. 250

Nitrate

ppm

tonnes/day

5

Approx. 700

2

Approx. 1,700

Phosphorous

ppm

tonnes/day

0.1

Approx. 10

0.01

Approx. 10

Suspended solids

ppm

tonnes/day

30

Approx. 4,000

100

Approx. 85,000

DO

ppm

8

8

 

 

 

 

 

Table 10.10 :  Discharges and Pollutant Loads of the Outfalls and Stormdrains near Central Assumed in the Modelling

Location Name

Easting

Northing

Volume

m3/day

Stormwater outfall K

835280

815815

1,521

Stormwater outfall I

834640

816025

2,143

Stormwater outfall J2

835015

815980

2,255

Stormwater outfall L

835440

815845

1,166

Stormwater outfall J1

834780

815990

7,430

Stormwater outfall F

834494

816168

2,400

 

 

Table 10.11 :  Water quality variable loads for the stormwater outfalls near Central

Location Name

BOD5

kg/day

TKN

kg/day

NH3-N

kg/day

E-coli

counts/day

Stormwater outfall K

28.9

4.4

4.4

6.16E+13

Stormwater outfall I

30.0

1.5

1.5

3.49E+13

Stormwater outfall J2

7.9

29

2.9

7.67E+12

Stormwater outfall L

304.3

17.5

17.5

7.93E+14

Stormwater outfall J1

2500.2

410.1

289.8

2.67E+15

Stormwater outfall F

600.0

150.0

60.0

4.80E+14

10.4.5.1.5                Due to the unstratified conditions in the dry season, and the limited stratification in the general study area during the wet season, all pollutant loads were assumed to rise to the surface.  During previous Hong Kong studies, it was determined by near field assessment that a simple function of the release thickness of the plumes against local current speed could be used for both seasons, and this function was also applied in the CRIII study.  Current speeds lower than 0.23ms-1 resulted in plumes being spread over the upper 38% of the water column.  Current speeds between 0.23ms-1 and 0.34ms-1 resulted in plumes being spread over the upper 63% of the water column, whilst speeds greater than 0.34ms-1 gave plumes spread over the upper 88% of the water column.

10.4.5.2            Results

10.4.5.2.1                For each combination of reclamation layout and seasonal condition simulated, the water quality model results are presented as contour plots of tide-averaged water quality parameters in the surface and bed layers of the model for the spring tide and the neap tide.  The parameters presented in this way are DO, BOD, unionised ammoniacal nitrogen, total inorganic nitrogen and coliforms.  DO, unionised ammoniacal nitrogen and total inorganic nitrogen are also presented as values averaged over both the tide and the water depth for the spring tide and the neap tide.  The method of contouring leaves areas white where values fall outside the range illustrated in the key. Therefore values are within the range of the key wherever non-white colours appear on the plots.
10.4.5.2.2                The modelling output for the Baseline Layout is presented both in graphical and tabular format in Appendix O.  The extent of the geographical area presented in the graphical output was carefully selected to provide maximum detail for the regions where changes were expected to occur in the Intermediate and Final Layouts.  At the boundaries of the graphical plots it can be seen that only very minor differences, if any, are present between Baseline and Intermediate / Final Layouts.  The quantitative magnitude of these changes for sensitive receivers outside the extent of the graphical plots is confirmed by the information contained in the Tables in Appendix O.  The information contained in Appendix O clearly demonstrates that sensitive receivers outside the boundaries of the modelled plots are not adversely affected by the CRIII works with all water quality parameters still found to comply with the stipulated WQOs at sent out in Chapter 3

Wet Season

10.4.5.2.3                The results of the wet season Baseline water quality simulations are presented in Figures 1.6a – 1.9b in Appendix O.
10.4.5.2.4                In the study area, tide-averaged DO concentrations (Figures 1.6a and 1.6b in Appendix O) are between 5.5 mgl-1 and 7.1 mgl-1 in the surface layer, and between 4.7 mgl-1 and 6.3 mgl-1 in the bed layer.  The higher values at shallower depths result from reaeration at the sea surface.  Depth-averaged DO concentrations (Figure 1.6c in Appendix O) are between 5.9 mgl-1 and 6.7 mgl-1 on spring tides and between 5.1 mgl-1 and 5.9 mgl-1 on neap tides; the higher concentrations on spring tides probably resulting from increased flushing of Victoria Harbour.  DO concentrations are generally lower at the sensitive receivers in Victoria Harbour than in other areas of the model.
10.4.5.2.5                Tide-averaged BOD5 concentrations in the model surface layer are between 0.5 mgl-1 and 6.0 mgl-1 in the study area (Figures 1.7a and 1.7b in Appendix O).  In general, concentrations are higher near the southern side of the Harbour than near the northern side, reflecting the presence of larger pollutant sources on the north shore of Hong Kong Island.  The highest BOD5 concentrations at the sea surface occur around the stormwater culverts between the Central Phase I reclamation and the HKCEC Extension at the Wan Chai outfall, (located to the North East of the HKCEC).  Due to the release of pollutants in the upper parts of the water column, BOD5 concentrations are generally lower near the sea bed than at the sea surface, and simulated wet season values at the bed range between 0.1 mgl-1 and 2 mgl-1 in the study area.  Simulated BOD5 concentrations at the sensitive receivers are generally higher in Victoria Harbour than in other parts of Hong Kong coastal waters, with maximum concentrations of between 2.1 mgl-1 and 2.5 mgl-1 at the sea surface at the Central and Wan Chai Intakes and the Central Water Front.
10.4.5.2.6                Qualitatively, the tide-averaged unionised ammoniacal nitrogen concentration distributions simulated for the wet season (Figures 1.8a and 1.8b in Appendix O) are similar to those of BOD5.  In the surface layer, values in the study area are between 0.001 mgl-1 and 0.1 mgl-1, whilst bed layer values vary between 0.001 mgl-1 and 0.01 mgl-1.  Depth-averaged values are between 0.001 mgl-1 and 0.04 mgl-1 (Figure 1.8c in Appendix O).  At the sensitive receivers, the highest unionised ammoniacal nitrogen concentrations occur at the sea surface at the Central, Wan Chai, Yau Ma Tei WSD and Western (East) Intakes, Central Water Front and Quarry Bay, where maximum instantaneous values range between 0.021 mgl-1 and 0.023 mgl‑1.
10.4.5.2.7                The simulated tide-averaged total inorganic nitrogen concentration distributions (Figures 1.8d and 1.8e in Appendix O) are qualitatively similar to those of ammoniacal nitrogen.  In the surface layer, values are in the range 0.1 mgl-1 to 0.8 mgl-1, and in the bed layer, values range from 0.1 mgl-1 to 0.3 mgl-1.  Depth-averaged values are in the range 0.1 mgl-1 to 0.5 mgl-1 on the spring tide and 0.2 mgl-1 to 0.5 mgl-1 on the neap tide (Figure 1.8f in Appendix O).
10.4.5.2.8                The simulated tide-averaged E. coli concentration distributions are also qualitatively similar to those of the other pollutants (Figures 1.9a and 1.9b in Appendix O).  Values simulated at the sea surface are between 103/100ml and 106/100ml in the study area, whilst values near the sea bed are between 103/100ml and 105/100ml.  The highest E. coli concentration maxim at the sensitive receivers in Victoria Harbour occur at the sea surface at the Central, Wan Chai and Western (East) Intakes, and Central Water Front, where values are in the range 6-11x104/100ml.
10.4.5.2.9                Simulated suspended solids concentrations at the sensitive receivers are in the range 0-2mg/l.  The suspended solids load of the Pearl River was included in the modelling, as were the processes of deposition and re-suspension at the sea bed.  The suspended solids measurements in Victoria Harbour made for the calibration of the original WAHMO mathematical models indicate concentrations in the approximate range 1-13mg/l in the wet season, and show little variation through the tidal cycle, whilst concentrations in the dry season were consistently less than 10mg/l.  The simulated suspended solids concentrations in the CRIII study are, therefore, towards the lower end of the range of observed values.  However, given the uncertainties involved in suspended sediment transport modelling, which result in model/observed concentration comparisons being considered good if they agree within a factor of about two, the present set of model results are considered to be reasonably consistent with observations.

Dry Season

10.4.5.2.10            The results of the dry season Baseline water quality simulations are presented in Figures 1.10a to 1.13b in Appendix O.
10.4.5.2.11            The simulated tide-averaged dissolved oxygen concentrations in the study area are generally higher in the dry season (Figures 1.10a and 1.10b in Appendix O) than in the wet season (Figures 1.6a and 1.6b in Appendix O), due to the lower ambient water temperature in the dry season, which leads to increased saturated DO values.  In the surface layer, dry season values in the study area are in the range 6.7 mgl-1 to 7.5 mgl-1, whilst bed layer values are between 6.3 mgl-1 and 7.1 mgl-1.  Depth-averaged values are in the range 6.3 mgl-1 to 7.1 mgl-1 on both spring and neap tides.
10.4.5.2.12            The qualitative tide-averaged pollutant concentration distributions simulated for the dry season, and ranges of values in the study area, are similar to the wet season.  Pollutant concentrations are generally higher in Victoria Harbour than in other areas of the model.  The highest instantaneous BOD5 concentrations at sensitive receivers occur at the sea surface at the Central and Western (East) Intakes and Central Water Front, where values are in the range 2.1 mgl-1 to 2.4 mgl-1.  These are also the sensitive receivers, together with Quarry Bay and Yau Ma Tei WSD Intake, with the highest instantaneous unionised ammoniacal nitrogen concentrations, in the range 0.020 mgl-1 to 0.023  mgl-1.  At these points, simulated maximum E. coli concentrations at the sea surface are between 3x104/100ml and 11x104/100ml.

10.5                                  Sediment Conditions

10.5.1                            In order to accurately determine sediment contamination levels, profiles and characteristics, site-specific sediment testing survey was undertaken by Gammon Construction. A Sediment Quality Study Report was prepared and copies submitted to the Principal Environmental Protection Officer of the Solid Waste Control Group of EPD (PEPOISWC) and the Fill Management Committee (FMC) Secretary of the Civil Engineering Department in April 1996 to fulfil the requirements of Marine Disposal of Dredged Mud existing at that time as set out in WBTC No. 22/92. The study included vibrocore fieldwork, laboratory analysis, and data interpretation.

10.5.2                            Vibrocore Fieldwork

10.5.2.1            The vibrocore fieldwork comprised sampling the marine deposits over the reclamation area for the earlier CRIII Full Reclamation Layout using 3 m long, 75mm diameter rigid plastic (PVC) sample tubes. Thirty seven samples were collected.  Of these thirty seven samples, twenty five are applicable to the CRIII Minimum Option Reclamation Layout.  The locations of these vibrocore stations applicable to the CRIII Minimum Option Layout are included in Appendix P.  The material encountered in the vibrocores applicable to the CRIII Minimum Option Layout had a typical profile comprising:

·                A thin layer (approx. 1m) of recent marine deposit - very soft, black silt/clay with shell fragments and organic matter;

·                A layer of Marine Deposit (from approximately 1m to 4m below the seabed. In some areas, marine deposits were found to be thicker than 4m below the seabed)- soft, dark greenish grey, sandy silty clay with occasional shell fragments; and

·                A layer of alluvium (below 4m depth) - brownish yellow, clayey/silty fine to coarse sand with occasional subangular fine to medium gravel.

Further extracts from the Sediment Quality Report which indicate the types and results of tests conducted on the samples removed that are applicable to the CRIII Minimum Option Layout are included on the following pages for reference.  Detailed information, as appropriate, is provided in Appendix P.

10.5.3                            Laboratory analysis

10.5.3.1            Three types of laboratory tests were carried out during the Sediment Quality Study in 1996 namely:

·                Test type 1 comprised:

-    Analysis for Chromium (Cr), Cadmium (Cd), Copper (Cu), Mercury (Hg), Nickel (Ni), Zinc (Zn) and Lead (Pb);

-    Analysis for dry weight;

-    Analysis for total organic carbon content (TOC);

-    Analysis for chemical oxygen demand; and

-    Analysis for electrochemical potential and conductivity.

·                Test type 2 comprised elutriate tests; and

·                Test type 3 comprised pore water tests.

10.5.3.2            Of the 25 vibrocore samples applicable to the CRIII Minimum Option Layout, 15 samples underwent laboratory analysis.  All of these samples were subject to Type 1 analysis, 3 samples were subject to Type 2 analysis, and 7 samples were subject to Type 3 analysis.   Details of the test types conducted on each sample are provided in Appendix P.

10.5.4                            Sediment Classification by Heavy Metal Contents

10.5.4.1            Classification Criteria

10.5.4.1.1                For the Sediment Quality Study conducted in 1996, sediments were classified according to their level of contamination by toxic metals as stipulated in the Environmental Protection Department Technical Circular No. 1-1-92, Classified of Dredged Sediments for Marine Disposal (Ref.3).  The contamination levels presented in the Technical Circular serve as criteria for determining the disposal requirements for the dredged sediments.  Definition of the classification is as follows:

·                Class A : Uncontaminated material, for which no special dredging, transport or disposal methods are required beyond those which would normally be applied for the purpose of ensuring compliance with EPD's Water Quality Objectives, or for protection of sensitive receptors near the dredging or disposal areas.

·                Class B : Moderately contaminated material, which requires special care during dredging and transport, and which must be disposed of in a manner which minimises the loss of pollutants either into solution or by re-suspension.

·                Class C : Seriously contaminated material, which must be dredged and transported with great care, which cannot be dumped in the gazetted marine disposal grounds and which must be effectively isolated from the environment upon final disposal.

10.5.4.1.2                The Technical Circular No. 1-1-92 contamination criteria for marine sediments are summarised in Table 10.12.  It should be noted that it is necessary for the concentration of only one metallic element to be exceeded for sediments to be identified as falling within a particular class.

Table 10.12 :  Classification of Sediments by Metal Contents (mg/kg dry weight)
(EPD Technical Circular No. (TC) No. 1-1-92)

 

Class *

Cd

Cr

Cu

Ni

Pb

Zn

Hg

A

0.0-0.9

0-49

0-54

0-34

0-64

0-140

0.0-0.7

B

1.0-1.4

50-79

55-64

35-39

65-74

150-190

0.8-0.9

C

1.5 or more

80 or more

65 or more

40 or more

75 or more

200 or more

1.0 or more

 

*    Class A - Uncontaminated;

     Class B - Moderately Contaminated;

     Class C - Seriously contaminated.

10.5.4.2            Sediment Classification

10.5.4.2.1                The results of the sediment classification for the vibrocore samples showed that throughout the CRIII Minimum Option Layout area, there were high levels of heavy metals in the bottom sediments which exceeded the Class C criteria particularly for copper, zinc and chromium. Generally the surface layer of the sediments (from seabed to approximately 1m, but at some locations as deep as 3m) is Class C (seriously contaminated). The contamination level of the mud reduces from 2m below the seabed, and generally reaches Class A levels at 3m.  Detailed results of the sediment classification are provided in Appendix P.

10.5.5                            Electrochemical Potential

10.5.5.1            The electrochemical potential (Eh) of the sediment is a measure of its oxidative or reductive state. Positive values indicate an aerobic environment and negative values indicate an anaerobic situation. Higher negative values indicate more anaerobic situations. The Eh values of the sediments in the CRIII Minimum Option Layout area are, (after the correction (-199 mV at 25 'C) for the difference in potential between silver: silver chloride and the standard hydrogen electrode), negative with a range from -132 to -4 mV indicating that bottom sediments in the CRIII Minimum Option Layout area are all anaerobic.  Detailed results for the electrical potential as obtained form the Sediment Quality Study conducted in 1996 are provided in Appendix P.

10.5.6                            Total Organic Carbon

10.5.6.1            The total organic carbon (TOC) content of sediment indicates the total amount of organic matter present in the sediment which will exert oxygen demand on the sediment as well as on the water column when it undergoes decomposition. The TOC content in the bottom sediment within the CRIII Minimum Option Layout area is generally high (up to 9.1% of dry weight) and unsatisfactory.  Detailed results for the TOC content as obtained from the Sediment Quality Study conducted in 1996 are provided in Appendix P.

10.5.7                            Elutriate Test of Micro-pollutants to Assess Potential Contaminant Release During Dredging

10.5.7.1            Elutriate tests are used to assess the potential of release of contaminants from marine mud sediment to the water when disturbed during dredging.  Heavy metals, ammoniacal nitrogen, PAHs, PCBs and tributyltin (TBT) were measured in the elutriate tests conducted as part of the Sediment Quality Study conducted in 1996.  The elutriate tests were carried out in accordance with Section 10.1.2.1 of the “Evaluation of Dredged Material Proposed for Ocean Disposal (Testing Manual)” prepared by the EPA / Office of Marine and Easturine Protection, Washington DC) and DOTA (United States Army Corps of Engineers, Washington DC) prepared under EPA Contract No. 68-C8-0105.  This publication is a recognised international document for consideration of environmental impacts associated with marine dredging works.  The detailed results of the elutriate tests applicable to the CRIII Minimum Option Layout for heavy metals, ammoniacal nitrogen and TBT are included in Appendix P.  The results for PAHs and PCBs are not included as the reporting limit for these parameters in the Sediment Quality Study are significantly higher than the equivalent United Kingdom Standards for them.  Further information on PCBs and PAHs within the dry sediment at the seabed of the CRIII Minimum Option Layout has, however, be obtained during further sediment quality studies conducted in late 2000.  These results are also included in Appendix P to enable them to be used to assess whether there would be any adverse impacts from PAHs or PCBs release during dredging operations.

10.5.7.2            Assessment of the results form the Sediment Quality Study works conducted in 1996  is based upon comparing the values obtained with applicable marine Water Quality Criteria (WQC).  No quantitative Water Quality Criteria are, however, available for the contaminants tested in the marine waters of Hong Kong.  In the absence of such criteria the standards used by the United Kingdom and provided in published reference manuals have been used (refer to Appendix P).  These show that at the point of dredging (the elutriate test simulates the effects at the location where the material is released into the water column), the levels of metals and TBT were below the limits of detection of the tests (and in general below the reference standards).  Whilst the results for copper and zinc do not prove conclusively that the reference standards can be satisfied differences between detection limits and the reference standards are small.  Nonetheless an additional assessment of the leaching potential of these contaminants has been carried out and is presented below. 

10.5.7.3            As indicated in paragraphs 10.5.7.1 - 10.5.7.2 above, the results of the earlier elutriate tests do not permit them to be conclusively used in assessing the potential for PAH, PCB, copper and zinc release during the dredging works. An approach based upon the use of the following equation, which represents the partitioning of pollutants between the absorbed and desorbed phases (this approach has been used on other EIA Studies in Hong Kong), has therefore been used to estimate the leaching potential of contaminants:

                 Ct = Cs + (Cs x Kd x SS)

where  Cs = concentration of contaminant in water (desorbed)

            Kd = partitioning coefficient

            SS = suspended sediment concentration

            Ct = SS x Csed

            Csed = concentration of contaminant in sediment

                 The values of the partitioning coefficients for PAHs, PCBs, copper and zinc were derived from previous studies which assessed the environmental impacts of the disposal of contaminated mud at East Sha Chau and dredging of an area of Kellet Bank for reprovisioning of six Government Mooring Bouys.  The partitioining coefficients used in these studies were:

          Partitioning  Coefficient for Total PAHs              0.075 Lg-1

          Partitioning Coefficient for Total PCBs              1,000 Lg-1

          Partitioning Coefficient for Copper                     122 Lg-1

          Partitioning Coefficient for Zinc                          100 Lg-1

These partitioning coefficients are considered applicable to the CRIII dredging site as the muds to be dredged from the CRIII site have similar chemical and sediment properties to the sediments for which the coefficients were derived in the earlier studies.

The concentation of PAHs, PCBs, copper and zinc in the sediment was derived from the sediment quality data collected in late 2000 and presented in Appendix P.  Maximum values included in the footnotes to Table P3 (in Appendix P) were used in the assessment.

The maximum predicted suspended sediment concentration used in the assessment is the maximum value pedicted for the CRII sensitive receivers considered in the Sedplume assessments (refer to Section 10.6 of this EIA Report).  The value adopted is 68.32mgL-1 as taken from Table 10.22.  The resulting desorbed concentration of PAHs, PCBs, copper and zinc in the marine waters will be:

PAHs :        = 0.115µgL-1

PCBs :        = 0.0001µgL-1

Copper :     = 1.77µgL-1

Zinc :          = 3.14µgL-1

The UK Standards that apply to PAHs, PCBs, copper and zinc are 5µgL-1 , 0.014µgL-1, 5µgL-1  and 40µgL-1 respectively.  It can therefore be concluded that there will be no adverse impacts to the water column from the release of the pollutants.

10.5.7.4            Both the results of previous elutriate tests conducted in 1995/1996 and further assessments using sediment quality data obtained in 2000 confirm that no adverse impacts will result from potential contaminant release i.e. leaching during dredging works.  An assessment of the leaching potential of PAHs, PCBs, copper and zinc using a partitioning coefficient approach shows comfortable compliance with the assessment criteria.  Although it is recognised that elutriate tests would be preferable, in the absence of sufficient elutriation data, the partitioning coefficient assessment approach is considered adequate for this study.

10.5.8                            Pore Water Analysis

10.5.8.1            In areas where marine sediments are left in place, pore water may be forced out of the sediment matrix during compaction and consolidation resulting in the release of contaminants. The results of the pore water tests conducted in the Sediment Quality Study indicate that pore water contains relatively lower concentrations of heavy metals than marine mud (based on a depth interval of 0.0 m and 0.9 m). The total organic carbon content was very high, ranging from 90 to 1850 mgl-1.  Detailed results of the pore water tests from the Sediment Quality Study conducted in 1996 applicable to the CRIII Minimum Option Layout are provided in Appendix P.

The Secretary of the Marine Fill Committee has confirmed that he has no objection to the proposal to remove 580,000m3 (i.e. total removal) of all soft seabed deposits from below the CRIII site.   Nonetheless, an assessment has been conducted to determine the potential for contaminant release associated with any small amounts of muds left in place.  In this situation contaminants contained in pore water could be forced out during subsequent reclamation works.  However, in view of the very low levels of contaminant present in the pore water from the tests conducted in the Sediment Quality Study and the dilution effect due to the receiving waters (refer also to section 10.5.7.1), it is considered that the impact on the receiving waters would be minimal.  Heavy metals such as mercury, cadmium and copper are relatively strongly bound to the clay fraction and organic material in the sediments and thus do not readily enter the sediment pore water.  The recorded TOC contents of 0.2% - 9.1% represent a high amount of organic matter in the bottom sediment of Victoria Harbour.  This organic matter plays an important role in binding of trace metals and organic micro-pollutants through sorption and / or complexation.  Thus the high recorded TOC content would indicate that pollutants in the sampled bottom sediments are likely to be less available to enter the sediment pore water.  Thus, it is considered that expelled pore water contamination would not be a concern for only small amounts of muds left in place.

10.6                                  Construction Phase Impact Assessment

10.6.1                            Introduction

10.6.1.1            This section presents a detailed environmental assessment of the potential water and sediment quality impacts associated with the construction and operation of the proposed reclamation of CRIII-MO. The assessment which was originally conducted for the CRIII-FR and CRIII-SO has been updated to account for the revised proposals for the CRIII-MO design and construction.

10.6.1.2            It should be noted that the impacts on the water quality, within the CRIII EIA report, have not included the impacts associated with the Wan Chai Development Phase II (WDII) reclamation works.  The CRIII water quality modelling was undertaken in this manner due to a lack information on the WDII works at the time the CRIII water quality modelling was undertaken.  However, details of the later cumulative water quality modelling undertaken by the WDII Consultant are included in Section 10.6.4.6 Appendix Q of this report.   This appendix shows the overall cumulative impacts of both the CRIII and WDII projects in respect to the construction and operational phases for water quality within the Victoria Harbour.

10.6.1.3            The key issues identified in terms of water quality relate to the presence of a temporary embayment in the study area during the construction phase. The embayment could lead to a decline in water circulation and flushing. Potential impacts to water quality include increases in temperature and elevation of biological oxygen demand (BOD), suspended solids (SS), and nutrients concentrations which may lead to decreases in dissolved oxygen (DO) concentration, and subsequent impacts upon sensitive receivers. Sensitive receivers include cooling water intakes in the vicinity of the study area, which serve a number of commercially important buildings in the Central Business District of Hong Kong.

10.6.1.4            The water quality near the study area has been subjected to serious pollution from human activities. In addition, the unmitigated disturbance of contaminated marine sediments within the study area may impact on water quality.   The reclamation method to be adopted for the CRIII Minimum Option involves the full removal of soft seabed deposits - full dredging (refer also to Chapter 2). This reclamation method would remove any biogas emissions which have been identified by Government as a concern when seabed sediments are left in place.

10.6.1.5            The placement of fill in the reclamation platform construction may lead to water quality impacts resulting from increases in SS, declines in DO, and impacts to cooling water intakes in the vicinity of the works area. The reclamation method to be adopted for the CRIII Minimum Option generally involves the use of marine sand for filling.  Some surplus soft fill material from land formation projects will be used for the reclamation platform below water.  This fill material will, however, be placed in fully enclosed areas of the reclamation and will therefore not be released to the waters of Victoria Harbour (refer also to Chapter 13).  As the filling will be conducted behind completed seawalls and within enclsoed areas there will be no adverse impact to the marine water quality of Victoria Harbour.  Potential impacts of both dredging and filling have been further investigated using mathematical water quality and hydraulic modelling. The modelling included investigation of potential mitigation measures.

10.6.1.6            In order to evaluate the water quality impacts during the construction phase, the proximity of Water Sensitive Receivers (WSRs) to the work sites must be considered. These have been specified in accordance with the Hong Kong Planning Standards and Guidelines (HKPSG), which provides guidelines for identifying environmental factors influencing development planning.

10.6.2                            Sediment Plume Modelling of Dredging and Filling

10.6.2.1            Introduction

10.6.2.1.1                The SEDPLUME-RW(3D) fine suspended sediment dispersal model was run to simulate the dispersal of sediment released into the water column during dredging and fill placement, using the flows simulated by TELEMAC-3D as input data.  Two simulations were carried out and, in each case, the flows for the relevant tide sequence were extracted from the TELEMAC-3D results file for the appropriate spring-neap cycle, and used repetitively in suspended mud dispersal simulations run over three consecutive diurnal cycles.
10.6.2.1.2                Suspended mud dispersal was simulated using the same values for the physical parameters as previous Hong Kong dredging studies carried out using the same model, (refer to Table 10.13), and suspended mud concentrations and mud deposit distributions were calculated on a 40m square grid.  This grid dimension was chosen to resolve relatively narrow suspended sediment plumes, and the channels and embayments around the CRIII reclamation.

Table 10.13 :  Physical parameter values used for the suspended sediment plume simulations

Parameter

Value/Equation

Settling velocity (m.s-1)

Maximum(Bcn,wsmin)

(c = suspended mud concentration, kg.m-3)

Minimum settling velocity, wsmin (m.s-1)

0.001

Settling velocity factor, B

0.01

Settling velocity power, n

1.0

Critical shear stress for deposition (N.m-2)

0.10

Critical shear stress for erosion (N.m-2)

0.11

Erosion constant (kg.N-1.s-1)

0.0007

10.6.2.2            Scenarios Simulated by the Sediment Plume Model

10.6.2.2.1                Table 10.14 summarises the information on the total volumes of material to be dredged/filled during the construction of the reclamation for CRIII.
10.6.2.2.2                In order to provide conservative results, all the dredging/filling rates used in the modelling were based on the factored volumes given in Table 10.14, which have been derived by multiplying the volumes by 1.5.  This factor of safety has been applied to produce conservative dredging and filling rates that might be specified in the Environmental Permit issued by EPD.  The filling rates specified are total reclamation volumes and therefore include fill material that will be placed above normal water level.

Table 10.14 :  Dredging and Filling Schedules

 

ITem

 

Description

Total

volume (TV)

(m3)

Factored

Volume

(TV*1.5)m3

 

Number of

weeks

Hourly

rate(1)/

daily rate (2)

 

Plant

1

Dredge

Initial West

100,000

150,000

16

98(1)

1 x 8m3
grab dredger

2

Fill Initial

West

250,000

375,000

14

4,464(2)

1x750m3
split hopper barge

3

Dredge

Initial East

180,000

270,000

16

176(1)

2x8m3
grab dredgers

4

Fill Initial

East

780,000

1,170,000

16

12,188(2)

1x1,000m3
split hopper barge

5

Dredge Final

West

200,000

300,000

17

184(1)

2x8m3
grab dredgers

6

Fill Final

West

(above EOT/Road P2) (3)

425,000

637,500

7

15,179(2)

1x1,000m3
split hopper barge

7

Dredge Final

East

100,000

150,000

16

98(1)

1x8m3
grab dredger

8         

Fill Final East

780,000

1,170,000

11

17,727(2)

1x1,000m3
split hopper barge

Notes        (1)       Hourly rate for dredging (m3/hour)

                (2)       Daily rates for filling (m3/day)

(3)       Surplus soft fill in Final Reclamation Area West will be placed behind completed seawalls in an enclosed area and therefore has not been considered in this water quality assessment.

10.6.2.2.3                The hourly and daily dredging rates for dredging and filling operations given in Table 10.14 were calculated by assuming a 16-hour working day and a 6-day working week.  The plant requirements are also given in Table 10.14.
10.6.2.2.4                In order to assess the cumulative impact of the CRIII reclamation dredging and filling works with other reclamation operations which are planned to be in operation at the same time, information was obtained from Government, in the early part of 1999, on reclamation projects with committed programmes which had a possible overlap with CRIII and would result in cumulative impacts. The projects identified were :

·                Yau Tong Bay Reclamation             April 2001 – September 2004

·                TKO Additional Reclamation           April 2004 – June 2004

At that time, no information was available in respect of the Wan Chai Development Phase II (WDII) project.  The Feasibility Study for that project only commenced in mid 1999.  Cumulative assessments for the combined reclamation activities for the CRIII and WDII projects may be found in the EIA Study Report for the WDII project but are also reproduced in Appendix Q for reference.

It should be noted that at the time the information was obtained the construction programme for CRIII was December 2000 – December 2004.  The consultants for the projects listed above were consulted and their reclamation programmes assessed to determine if concurrent reclamation works would occur.  This work revealed that only the Yau Tong Bay project would have concurrent reclamation construction activities.  Information on the dredging for the reclamation in Yau Tong Bay was taken from the Draft EIA Report for the Reclamation at Yau Tong Bay (YTB), extracts from which were provided by Maunsell Environmental Management Consultants Ltd.  The YTB reclamation will take place between August 2001 and September 2004.  Only the filling activity for the Phase 1 reclamation was modelled for this study.  In order to provide conservative results, it was assumed that filling will take place before the YTB sea wall has been constructed.  In practice, the seawall will be constructed with a 50m gap, with barges bulk filling by bottom dumping behind the near-complete seawall.  The dry density of the filling sand for the YTB reclamation was taken to be 1,835kg.m-3. 

10.6.2.2.5                Two sediment plume modelling scenarios were simulated. Table 10.15 gives details of the dredging/filling activities for CRIII and Yau Tong assessed in each scenario, which were chosen in consultation with EPD.  Scenario 1 included filling of the Initial West and Initial East areas at CRIII, whilst Scenario 2 included dredging and filling of the Final East area of CRIII.   Whilst these activities would not be ongoing concurrently in the programme included in Appendix C of this report, it was considered that they presented a worst case scenario and would take account of any possible adjustments to the programme.  Figures 10.1a and 10.1b show the locations of the dredgers/barges at CRIII specified for Scenarios 1 and 2 respectively.  Figure 10.2 shows the location sediment sources for the Yau Tong Bay Reclamation (concurrent project) considered in the assessment.

Table 10.15 :  Sediment release for the two scenarios

Scenario

 

Description

Hourly
Rate(1)/
daily rate

(2)

 

Plant

Dump
Interval
(hours)

Fines
Release rate

Maximum
fines
release rate
(kg.s-1)

1

 

Fill Initial East

12,200(2)

1x1,000m3
split hopper barge

1.3

13.33(3)

23.33

Fill Initial West

4,500(2)

1x750m3
split hopper barge

2.7

10.00(3)

Yau Tong

--

--

-

18.86

18.86

2

Dredge Final East

100(1)

1x8m3
grab dredger

-

1.86

15.19

Fill Final East

17,800(2)

1 x 1,000m3
split hopper barge

0.9

13.33(3)

Yau Tong

--

--

-

18.86

18.86

Notes      (1)           Hourly rate for dredging (m3/hour)

(2)       Daily rates for filling (m3/day)

(3)       Calculated by assuming that the barge containing the fill releases its load over a period of 5 minutes.  5% of the sand fill is composed of fines and 5% of these fines are lost to the entire water column.  The dry density of the sand fill is 1,600kg/m3.

10.6.2.2.6                For the dredging operation, a dry density of 1,340kg.m-3 has been assumed for the dredged material in deriving the figures.  This figure has been obtained by reference to data collected during the Site Investigation for the CRIII project.  The sediment release rates (kg.s-1) were calculated by assuming that 5% of the dredged material is lost to the entire water column, and that this loss is continuous.
10.6.2.2.7                During the planned filling operations for CRIII, barges will bottom dump marine sand fill.  In the modelling, it was assumed that fines released during this activity will be lost to the entire water column, as occurs when sea water is entrained into a descending column of sediment.
10.6.2.2.8                The dry density of the marine sand fill material is 1,600kg.m-3, of which 5% were assumed to be fines, and 5% of the fines were assumed to be lost to the water column during filling.  The value for the dry density was obtained through consultation with contractors currently engaged on other reclamation projects within Hong Kong.  It was assumed that the barges discharge their loads over periods of 5 minutes, generating intermittent sediment release sources.
10.6.2.2.9                In selecting the tide types to be used for the two scenarios under consideration, use was made of the findings of previous studies conducted for the project site and the findings of the Wan Chai Development Phase II water quality modelling works.

Detailed sediment dispersion modelling works conducted as part of these studies examined both “far field” impacts on sensitive receivers outside Victoria Harbour using tides with larger tidal excursions and “near field” impacts (particularly at the numerous seawater intakes located in the Central and Wan Chai Districts of Hong Kong Island) using tides with smaller tidal excursions. The key findings of both study works were essentially the same and may be summarised as below.

Far field Impacts:  Sediment plumes generated by dredging and filling activities distant from the existing shoreline (in areas of water flow with significant magnitude) can extend some distance from the site both to the east and west.  The magnitudes of SS elevations, however, decrease rapidly with distance from the site and only negligible SS elevations only are predicted outside the confines of the inner Victoria Harbour. 

In previous water quality model studies for the project site conducted in 1996/1997, the sediment plume model, SedPlume, which formed part of the WAHMO suite of coastal hydraulic and water quality models was used to simulate various dredging and filling scenarios.  Two scenarios modelled considered dredging and filling activities at the extreme boundaries of the CRIII Minimum Option  project site and thus in areas of strong current flows.  These two modelled scenarios used the dry season spring tide as it was assessed that this tide, which has the largest tidal excursion, would give the largest area impacted by elevated suspended sediment concentrations.  Full details of the two scenarios modelled and results are provided in Appendix R of this report.

The results  show that for the scenarios modelled with spring tides (maximising far field impacts), sediment plumes can extend some distance from the project site.  The plumes, however, remain within the confines of the inner Victoria Harbour and do not extend as far as Green Island to the west where the ecological conditions are not as degraded as for the remainder of the inner harbour.

In the Wan Chai Development Phase II water quality modelling works, the furthest sensitive receivers from the site were at Kennedy Town (to the west) and Siu Sai Wan (to the east).  The maximum suspended solids levels (unmitigated) predicted at Kennedy Town and Siu Sai Wan in the dry season were 11.3mgl-1 and 8.3mgl-1 respectively. These values compare to the maximum values predicted at sensitive receivers along the Wan Chai waterfront of 255.3mgl-1.  Similar phenoma are predicted for the wet season with maximum suspended solids levels of 6.6mgl-1 and 13.8mgl-1 predicted at Kennedy Town and Siu Sai Wan respectively compared to 262.8mgl-1 along the Wan Chai waterfront.  The magnitudes of these SS elevations distant from the site are expected to be able to meet the respective intake criteron after mitigation. The  most significant SS elevations are found close to the site potentially affecting the numerous seawater intakes located in the Central and Wan Chai Districts of Hong Kong Island.

Near Field Impacts : Sediment plumes generated by dredging and filling activities near to the existing shoreline (in areas of water flow of low magnitude) can also extend some distance from the site particularly to the west on the flood tide.  The sediment plumes, which were produced under more conservative fines loss rates, generally remain within the confines of the inner Victoria Harbour.  The magnitudes of these SS elevations are found to be similar to those predicted for the “far field” impact simulations.

As would be expected, the “near field” impact simulations predict maximum SS elevations close to site.  The magnitudes of the SS elevations are, however, larger than for the “far field” impact simulations principally due to the following reasons :

·                The sediment sources are located much closer to the shoreline (and seawater intakes); and

·                The sediment sources are located in areas of water flow with low magnitude.

Such high SS elevations will affect the numerous seawater intakes located in the Central and Wan Chai Districts of Hong Kong.

10.6.2.2.10            The extent and limits of the reclamation for the Minimum Option layout are substantially reduced from those considered in the previous studies for the project site and in keeping with the Wan Chai Development Phase II studies, dredging and filling activities will be conducted is close proximity to the existing shoreline (intermediate reclamation areas) or in close proximity the shoreline formed by the initial reclamation areas as illustrated in Figures 4.1 and 4.2 of the EIA Report (refer to Chapter 4).

The sequence of dredging and filling works for the Minimum Option reclamation will also be carried out largely behind completed seawalls due to the configuration of the completed reclamation.  The sequence of the reclamation will require that the reclamation platform be formed from a number of small reclamations (refer to Figures 4.1 and 4.2 in Chapter 4 of this EIA Report).  As a consequence, the majority of dredging and filling works will be carried out in areas of water flow of low magnitude (refer to Baseline plots in Appendix O).  Even the dredging and filling works at the limits of the reclamation will be in areas of relatively low water flow with the most exposed area being close to the existing Ferry Pier 7 at the north west corner of the reclamation.

Taking account of the findings of previous studies for the project site (refer to Appendix R), the Wan Chai Development Phase II water quality modelling works (refer to paragraph 10.6.2.2.9) and the manner in which the reclamation will be constructed, it was determined that priority should be given to considering the impacts on seawater intakes located within the site and the areas immediately adjacent to the site where SS elevations would be maximum.  Tide types which would be associated with short tidal excursions were therefore adopted.

10.6.2.3            Results of the Sediment Plume Modelling

10.6.2.3.1                In addition to the sensitive receivers described in Section 10.2, further sensitive receivers were used in the Central area for the suspended sediment results, as shown in Figures 10.3 and 10.4 for Scenarios 1 and 2 respectively.  At the sensitive receivers, suspended mud concentrations are presented as time-series for each model layer and as a depth-average for the final 25-hour period of each 75-hour simulation.  The maximum and mean values of these time-series are also tabulated.

Scenario 1 (Filling)

10.6.2.3.2                Figures 10.5-10.6 show suspended sediment concentrations in the surface and bed layers of the model at peak flood and peak ebb for Scenario 1.  Time-series plots for this scenario are presented in Figures 10.7-10.11.
10.6.2.3.3                The highest suspended mud concentrations simulated in Scenario 1 result directly from the filling at YTB. This activity is the cause of the relatively high concentrations (20-40mg.l-1) simulated at the Cha Kwo Ling and Yau Tong sensitive receivers (Figure 10.10), and at the Yau Ma Tei WSD Intake where WSD criteria in respect of SS criteria may be exceeded.  Whilst the simulations assess concurrent reclamations CRIII and YTB, the elevations at Yau Ma Tei WSD intake could not be attributable to CRIII works as illustrated in Figure 10.12 which demonstrate the elevation in SS levels associated with CRIII reclamation works remain localised to the Hong Kong island shoreline.  This issue of SS levels at the Yau Ma Tei WSD intake should have been addressed in the EIA Study for Yau Tong Reclamation.
10.6.2.3.4                A plume with elevated SS concentrations extends from the CRIII filling site along the Central Reclamation Phase I to Sheung Wan in the upper layer.  Maximum elevated concentrations are immediately adjacent to the filling site with a maximum value of around 40 mgl-1 at the Central Barracks intake (Figure 10.11).  No significant increases in sediment are present to the east of the site.
10.6.2.3.5                On the ebb tide, plumes are limited to close to the site of filling.  Elsewhere on the ebb tide in the surface layer suspended sediment concentrations are less than 10 mgl-1.  In the lower layer, the pattern of suspended sediment concentrations is similar to that in the upper layer but with higher concentrations further away form the dredging site.
10.6.2.3.6                The predicted impacts described above would violate the WQO’s standard for SS (which only allows an increase of 30% of ambient (“background”) in SS concentration).  For the CRIII area the ambient concentrations have been determined using data collected at the EPD monitoring station VM5.  Ambient SS levels (90th percentile) of 7.3 mgl-1 and 7.1 mgl-1 have been adopted for the CRIII area for the wet and dry seasons respectively.  Figure 10.12 indicates the extent of the mixing zone around the suspended sediment sources, in which the model predicts 30% of ambient i.e. 2.2mgl-1 to be exceeded.  It should be noted, however, that the predicted concentrations are much lower than the recommended maximum value for cooling water intakes as indicated in Chapter 3 of this EIA Report.
10.6.2.3.7                Net deposition in Scenario 1 (refer to Figure 10.13) occurs mainly in the vicinity of the dredging/filling for the Central reclamation and at YTB, and along the margins of Victoria Harbour.  The highest net deposition rates simulated in Scenario 1 result directly from the filling at YTB.  Near the CRIII site, typical net deposition rates are in the range 0.1kg.m-2 to 0.5kg-2 per day.
10.6.2.3.8                The contour plots also show that elevations of SS at the WSD Wanchai and North Point flushing water intakes are negligible and when combined with the ambient concentrations (refer to paragraph 10.6.2.3.6) will not exceed the specified WSD criteria.

10.6.2.4            Scenario 2 (Dredging & Filling)

10.6.2.4.1                Suspended sediment concentrations in the surface and bed layers of the model at peak flood and peak ebb are shown for Scenario 2 in Figures 10.14 and 10.15.  Time-series plots for this scenario are presented in Figures 10.16 - 10.20.
10.6.2.4.2                As in Scenario 1, the highest concentrations at the sensitive receivers outside the CRIII area are at Cha Kwo Ling (Figure 10.19), where values peak at around 70mg.l-1resulting directly from filling operations at YTB.
10.6.2.4.3                For the flood tide in both the upper and lower layers the highest elevated concentrations of sediment, directly associated with the CRIII works, are confined to the immediate area of the filling east of the Initial Area East.  The main plume is shown to extend around Initial Area East and along the face of the CRI.  On the ebb tide very little sediment associated with the CRIII works is shown to be transported away from the CRIII site in either the upper or lower layers.  The highest elevated concentrations, are again shown in the immediate vicinity of the filling operation east of Initial Area East with the highest concentration at the relocated intake of the Queensway Government Offices (Figure 10.20).  Suspended solids concentrations at intakes along the CRI are shown to reach maximum increase of less than 10 mgl-1.
10.6.2.4.4                The predicted impacts described above would violate the WQO’s standard for SS (which only allows an increase of 30% of ambient (“background”) in SS concentration).  For the CRIII area the ambient concentration have been determined using data collected at the EPD monitoring station VM5).  Ambient SS levels (90th percentile) of 7.3mgl-1 and 7.1 mgl-1 have been adopted for the CRIII area for the wet and dry seasons respectively.  Figure 10.21 indicates the extent of the mixing zone around the suspended sediment sources, in which the model predicts 30% of ambient i.e. 2.2mgl-1 to be exceeded,  It should be noted, however, that the predicted concentrations are lower than the recommended maximum value for cooling water intakes as indicated in Chapter 3 of this EIA Report.
10.6.2.4.5                Net deposition in Scenario 2 (refer to Figure 10.22) is qualitatively similar to that in Scenario 1.  The maximum deposition rates near the CRIII area are in the immediate vicinity of the sediment sources there, and are up to 20kgm-2 per day, although values only exceed 5kgm-2 per day within a zone of diameter approximately 100m around the sources.
10.6.2.4.6                The contour plots also show that elevations of SS at Wanchai and North Point WSD flushing water intakes are negligible and when combined with the ambient concentrations (refer to paragraph 10.6.2.4.4) will not exceed the specified WSD criteria.

The predicted maximum SS levels at sensitive receivers (both cooling water intakes and WSD intakes) are observed to be, in both modelled cases, substantially below the specified Water Quality Objectives (refer to section 3.6).  Given that the modelling input utilised dredging and filling rates based upon the  construction programme presented in Appendix C, it is worth noting that significant increases in these rates would produce SS levels at all sensitive receivers that still comply with the WQOs.  This observation was obviously only possible upon completion of modelling at which time the input data could not be amended.  It is, however, particularly relevant to the preparation of the Environmental Permit for the project.

Dissolved Oxygen Depletion

10.6.2.4.7                An assessment of the impacts of suspended solids concentrations has been carried out for both modelled scenarios.  Dissolved oxygen depletion (mgl-1) associated with dredging and filling activity can be estimated using the equation.

DOdep           =       C x COD x 0.001

where

DOdep           =       reduction in dissolved oxygen level in mgl-1

C                   =       tidal average suspended sediment concentration in kg m-3

COD             =       chemical oxygen demand in mg-O kg-1 sediment

The value of COD is taken from Table D16 of Appendix D of the publication - “Marine Water Quality in Hong Kong in 1997” as no site specific data is available.  The value adopted is that for station VS5 (the closest station to the CRIII site) and is the maximum recorded value of 25,000 mg kg-1.

Tables 10.16 – 10.20 and Tables 10.21 – 10.25 for Scenarios 1 and 2 respectively indicate that the maximum tide – averaged suspended mud concentration at any of the relevant sensitive receivers (cooling water intakes are not relevant sensitive receivers) resulting from the simulated dredging / filling from the CRIII works is 0.09 mgl-1 (at the WSD Wan Chai Intake in Scenario 2).  The values quoted in these tables are elevations above ambient (“background”) and do not include the ambient concentration.  Consequently the maximum dissolved oxygen depletion associated with the reclamation works for CRIII can be estimated to be 0.00225 mgl-1.  This decrease of the dissolved oxygen is small when compared to the Baseline valves (refer to paragraph 10.4.5.2.4 and therefore will not impact the dissolved oxygen concentration of the water column when compared to the WQO for DO as defined in Table 3.8  and the WSD's DO objective as defined in Table 3.10 (refer to Chapter 3).

Micropollutants

10.6.2.4.8                The only information available on micropollutant levels in sediments and porewater within the CRIII area is that collected in the Sediment Quality Study in 1996 (refer to section 10.5).  This Sediment Quality Study concluded, based upon elutriate test results, that no detectable micropolutants were found in the elutriates obtained from the sediments in the CRIII area.  Therefore based upon these results contamination by the release of these micropollutents during reclamation works will not to be a concern for the CRIII reclamation.

Nutrients

10.6.2.4.9                Nutrient concentration elevations associated with dredging and filling activity can be estimated approximately using a similar procedure to that described for DO depletion above.  This assumes that all nutrients associated with the sediment are lost to suspension, and are transported and diluted at the same rates as the sediment in suspension.  The values of sediment nitrogen concentration are taken from Table D16 of Appendix D of the publication – “Marine Water Quality in Hong Kong in 1997 “as no site specific data is available.  The values adopted are the total Kjeldahl Nitrogen and Ammonical Nitrogen for station VS5 (the closest station to the CRIII site). The maximum recorded valves of these parameters are 620mg kg-1 and 1.2 mg kg-1 respectively.  Use of these values with the 7.68mg/l-1 maximum sensitive receiver suspended mud concentration (refer to Table 10.22) associated with dredging gives a maximum possible inorganic nitrogen elevation estimate of 0.0050 mg/l and a maximum possible ammonical nitrogen elevation of 0.01µg/l.  These elevations are very small and will not impact the overall nitrogen or ammonia concentrations within the water column when compared to the water quality objective for nutrients as defined in Table 3.8 and the WSD’s objective for Ammonical Nitrogen as defind in Table 3.10 (refer also to Chapter 3).


 

Table 10.16 : Simulated depth-averaged suspended mud concentrations given as elevation above ambient – Scenario 1

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.30

0.84

Central Water Front

0.87

6.28

Cha Kwo Ling

2.70

14.97

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.19

Green Island South

0.00

0.11

Green Island West

0.02

0.30

Hotel Furama Intakes

0.41

1.92

HSBC Intake

0.47

2.16

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

0.21

4.69

Central Barracks Intake

4.95

32.56

Prince's Building Group

0.78

3.64

Quarry Bay

0.04

0.56

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.93

4.30

Queensway Government Offices

0.64

5.25

Sai Wai Ho

0.01

0.32

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

0.34

2.57

Wan Chai WSD Intake

0.01

0.16

Western Intake (Central)

0.60

2.72

Western Intake (East)

0.41

1.39

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.35

3.47

Yau Tong

1.21

9.01

 

Table 10.17 : Simulated suspended mud concentrations given as elevation above ambient in the bed layer – Scenario 1

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.77

2.81

Central Water Front

1.50

15.65

Cha Kwo Ling

5.21

31.74

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.01

0.75

Green Island South

0.02

0.44

Green Island West

0.06

1.18

Hotel Furama Intakes

1.13

6.93

HSBC Intake

0.98

4.52

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

0.40

5.64

Central Barracks Intake

6.80

37.66

Prince's Building Group

1.00

6.74

Quarry Bay

0.12

2.23

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

1.54

6.95

Queensway Government Offices

1.07

13.91

Sai Wai Ho

0.03

0.59

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

0.58

9.11

Wan Chai WSD Intake

0.04

0.66

Western Intake (Central)

1.72

7.43

Western Intake (East)

0.78

3.61

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

1.11

13.89

Yau Tong

2.84

23.95

 

 

 

Table 10.18 : Simulated suspended mud concentrations given as elevation above ambient below mid-depth : Scenario 1

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.29

1.73

Central Water Front

0.98

11.85

Cha Kwo Ling

4.08

37.04

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.01

0.40

Hotel Furama Intakes

0.47

2.18

HSBC Intake

0.65

4.85

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

0.39

14.13

Central Barracks Intake

6.02

43.26

Prince's Building Group

1.03

5.89

Quarry Bay

0.02

0.54

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.77

2.76

Queensway Government Offices

0.93

15.99

Sai Wai Ho

0.02

0.59

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

0.42

6.92

Wan Chai WSD Intake

0.01

0.39

Western Intake (Central)

0.60

4.32

Western Intake (East)

0.45

2.79

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.23

3.41

Yau Tong

1.81

18.26

 

Table 10.19 : Simulated suspended mud concentrations given as elevation above ambient above mid-depth : Scenario 1

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.07

0.90

Central Water Front

0.89

11.46

Cha Kwo Ling

1.45

14.54

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

Hotel Furama Intakes

0.05

1.70

HSBC Intake

0.24

4.30

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

0.06

2.39

Central Barracks Intake

4.90

39.87

Prince's Building Group

0.88

6.82

Quarry Bay

0.02

0.55

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.82

10.61

Queensway Government Offices

0.57

10.73

Sai Wai Ho

0.01

0.59

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

0.35

4.12

Wan Chai WSD Intake

0.01

0.41

Western Intake (Central)

0.09

1.54

Western Intake (East)

0.29

2.99

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.04

1.75

Yau Tong

0.17

1.88

 

 

 

Table 10.20 : Simulated suspended mud concentrations given as elevation above ambient in the surface layer, Scenario 1

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.05

1.72

Central Water Front

0.11

1.37

Cha Kwo Ling

0.06

0.40

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

Hotel Furama Intakes

0.00

0.00

HSBC Intake

0.00

0.15

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

0.00

0.00

Central Barracks Intake

2.07

33.68

Prince's Building Group

0.19

1.88

Quarry Bay

0.00

0.00

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.60

3.95

Queensway Government Offices

0.00

0.14

Sai Wai Ho

0.00

0.00

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

0.00

0.20

Wan Chai WSD Intake

0.00

0.00

Western Intake (Central)

0.00

0.00

Western Intake (East)

0.10

1.58

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.00

0.00

Yau Tong

0.00

0.00

 

Table 10.21 : Simulated depth-averaged suspended mud concentrations given as elevation above ambient - Scenario 2

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.13

0.68

Central Water Front

0.93

7.21

Cha Kwo Ling

2.57

32.77

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

HSBC/Hotel Furama Intake

4.10

30.93

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

3.91

30.39

Prince's Building Group

1.35

9.11

Quarry Bay

0.56

3.04

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

1.11

9.11

Queensway Government Offices

5.34

41.24

Sai Wai Ho

0.48

5.32

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

1.41

15.13

Wan Chai WSD Intake

0.06

0.66

Western Intake (Central)

0.24

1.84

Western Intake (East)

0.22

1.73

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.18

3.29

Yau Tong

0.49

5.47

 

Table 10.22 : Simulated suspended mud concentrations given as elevation above ambient in the bed layer - Scenario 2

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.39

2.72

Central Water Front

1.31

13.02

Cha Kwo Ling

6.02

66.66

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

HSBC/Hotel Furama Intake

3.91

40.10

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

7.68

51.19

Prince's Building Group

3.00

21.50

Quarry Bay

2.22

12.17

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

2.48

14.39

Queensway Government Offices

4.99

68.32

Sai Wai Ho

1.80

20.11

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

2.20

13.63

Wan Chai WSD Intake

0.05

0.95

Western Intake (Central)

0.57

6.69

Western Intake (East)

0.43

5.18

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.72

13.15

Yau Tong

1.01

11.75

 

Table 10.23 : Simulated suspended mud concentrations given as elevation above ambient below mid-depth - Scenario 2

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.07

1.97

Central Water Front

0.87

8.36

Cha Kwo Ling

3.45

51.88

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

HSBC/Hotel Furama Intake

5.84

42.70

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

6.33

50.52

Prince's Building Group

0.64

8.67

Quarry Bay

0.03

0.54

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.38

7.90

Queensway Government Offices

6.27

63.57

Sai Wai Ho

0.12

1.23

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

0.50

7.01

Wan Chai WSD Intake

0.08

2.07

Western Intake (Central)

0.39

3.99

Western Intake (East)

0.19

4.47

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.00

0.00

Yau Tong

0.89

15.21

 

 

 

Table 10.24 : Simulated suspended mud concentrations given as elevation above ambient above mid-depth - Scenario 2

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.01

0.32

Central Water Front

1.38

11.77

Cha Kwo Ling

0.76

12.54

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

HSBC/Hotel Furama Intake

5.53

43.99

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

1.60

19.86

Prince's Building Group

1.22

9.40

Quarry Bay

0.00

0.00

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.96

11.21

Queensway Government Offices

7.48

48.80

Sai Wai Ho

0.00

0.00

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

1.85

35.05

Wan Chai WSD Intake

0.09

1.50

Western Intake (Central)

0.00

0.00

Western Intake (East)

0.25

3.20

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.00

0.00

Yau Tong

0.08

3.11

 

 

 

Table 10.25 : Simulated suspended mud concentrations given as elevation above ambient in the surface layer - Scenario 2

Location

Concentrations (mg l-1)

Average

Maximum

Central Intakes

0.07

2.19

Central Water Front

0.16

3.03

Cha Kwo Ling

0.04

0.50

Cheung Sha Wan WSD Intake

0.00

0.00

Green Island East

0.00

0.00

Green Island North

0.00

0.00

Green Island South

0.00

0.00

Green Island West

0.00

0.00

HSBC/Hotel Furama Intake

1.14

11.71

Kau Yi Chau Fishery

0.00

0.00

Kennedy Town WSD intake

0.00

0.00

MTRC Intake

0.00

0.00

MTRC South Intake

0.01

0.76

Prince's Building Group

0.54

7.08

Quarry Bay

0.00

0.00

Queen Mary Hospital Intake

0.00

0.00

Queen's Piers 6 & 7

0.64

11.45

Queensway Government Offices

2.61

24.37

Sai Wai Ho

0.00

0.00

Stage 1 Phase 1 Intake

0.00

0.00

Tai Wan

0.00

0.00

Wah Fu Estate Intake

0.00

0.00

Wan Chai Intakes

1.10

25.45

Wan Chai WSD Intake

0.03

1.32

Western Intake (Central)

0.00

0.00

Western Intake (East)

0.00

0.00

Western Intake (West)

0.00

0.00

Yau Ma Tei WSD Intake

0.00

0.00

Yau Tong

0.00

0.00

 

10.6.3                            Water Quality Modelling of the Intermediate Layout

10.6.3.1            Introduction

10.6.3.1.1                The reclamation layout at an intermediate stage of CRIII construction only was included in the model mesh, and the hydrodynamic and water quality models were run for wet season conditions, using the same boundary and initial conditions as the Baseline wet season simulation.  No other changes to the coastline configuration were made.  At the time of modelling no information was available in respect of the Wan Chai Development Phase II project.  The Feasibility Study for that project only commenced in mid 1999.  The wet season was selected for modelling for the Intermediate Layout after a review of the Baseline and Final Layout modelling results.  The mesh used for this Intermediate Scenario is illustrated in Figure 2.1 in Appendix O.  In areas outside the reclamation, sea bed depths were unchanged from the Baseline.
10.6.3.1.2                The modelling output for the Intermediate Layout is presented both in graphical and tabular format in Appendix O.  The extent of the geographical area presented in the graphical output was carefully selected to provide maximum detail for the regions where changes were found to occur when compared to the Baseline Layout output.  At the boundaries of the graphical plots it can be seen that only very minor differences, if any, are present between Intermediate and Baseline Layouts.  The quantitative magnitude of these changes for sensitive receivers outside the extent of the graphical plots is confirmed by the information contained in the tables.

10.6.3.2            Water Movement

10.6.3.2.1                Figures 2.2a and 2.2b in Appendix O show the simulated surface flow patterns in the study area for spring and neap tides in the wet season.  Contour plots of simulated maximum speeds for the same tides at the sea surface and sea bed are shown in Figures 2.3a and 2.3b in Appendix O.
10.6.3.2.2                The current speed distributions are very similar to the equivalent wet season Baseline results (Figures 1.3a and 1.3b in Appendix O).  The effects of the partial construction can be seen just east of the main reclamation as a slight expansion of the area within the 0-0.25ms-1 contour band at the surface on the neap tide, but there are no other noticeable changes.

10.6.3.3            Pollutant Loads

10.6.3.3.1                Loadings of water quality parameters used for the Intermediate Scenario were the same as those used for the Baseline, except for relocations of some culverts necessitated by the presence of the reclamation.   Where multiple culverts in the Baseline simulations were relocated to a single location for the construction phase, the loads of the contributing sources were summed.  Details of the stormwater culverts used in the Intermediate Scenario are summarised in Tables 10.26 and 10.27 and illustrated on Figure 10.23.

 

Table 10.26 :  Locations and discharges of the stormwater outfalls near Central during the construction phase

Location Name

Easting

Northing

Volume

m3/day

Stormwater outfall K

835280

815815

1,521

Stormwater outfall I

834640

816025

2,143

Stormwater outfall J

835076

816077

9,685

Stormwater outfall L

835440

815845

1,166

Stormwater outfall F

834494

816168

2,400

 

Table 10.27 :  Water quality variable loads for the stormwater outfalls near Central during the construction phase

Location Name

BOD5

kg/day

TKN

kg/day

NH3-N

kg/day

E-coli

Counts/day

Stormwater outfall K

28.9

4.4

4.4

6.16E+13

Stormwater outfall I

30.0

1.5

1.5

3.49E+13

Stormwater outfall J

2508.1

413.0

292.7

2.68E+15

Stormwater outfall L

304.3

17.5

17.5

7.93E+14

Stormwater outfall F

600.0

150.0

60.0

4.80E+14

10.6.3.4            Impacts

10.6.3.4.1                The results of the wet season intermediate water quality simulations are presented in Figures 2.4a to 2.7b in Appendix O.
10.6.3.4.2                The DO concentrations simulated for the Intermediate Layout (Figures 2.4a and 2.4b in Appendix O) are very similar to those simulated for equivalent Baseline conditions (Figures 1.6a and 1.6b in Appendix O).  The most noticeable difference is a small reduction in bed layer DO values to below 5.5  mgl-1 on the spring tide adjacent to the Central Phase I reclamation, in the corner created by the eastward extension of this reclamation.  This is believed to result from increased deposition of suspended solids in the slack area created by the works, and associated enhanced sediment oxygen demand.
10.6.3.4.3                The relocation of the Outfall J1 discharge to Outfall J, which has the largest BOD5 load of the stormwater outfalls in the Central area, in the Intermediate Layout, results in reduced BOD5 concentrations in the embayment to the east of the Central Phase I reclamation (Figures 1.7a – 1.7b and 2.5a - 2.5b in Appendix O).  Due to the higher current speeds at the relocated site of this outfall (Outfall J), on the seaward face of the main reclamation, the outfall has a reduced effect on BOD5 concentrations relative to its Baseline location.  Elsewhere, BOD5 concentration distributions are similar for the Baseline and Intermediate Layouts.
10.6.3.4.4                Changes in unionised ammoniacal nitrogen and total inorganic nitrogen concentrations between the Baseline and Intermediate Layouts (Figures 1.8a – 1.8f and 2.6a – 2.6f in Appendix O) are qualitatively similar to changes in BOD5 concentrations, with the water quality improvement associated with the relocation of Outfall J1 to Outfall J dominating over any deterioration associated with the creation of the embayment. It is considered that most of the ammoniacal nitrogen is discharged from sewage outfalls of the Victoria Harbour and that the reclamation activities and the intermediate layout of the proposed reclamation would not be the main factor of the local elevation of ammoniacal nitrogen.
10.6.3.4.5                Changes in E. coli concentrations between the Baseline and Intermediate Layouts (Figures 1.9a – 1.9b and 2.7a – 2.7b in Appendix O) are qualitatively similar to changes in BOD5 concentrations, with the water quality improvement associated with the relocation of Outfall J1 to  Outfall J dominating over any deterioration associated with the creation of the embayment.  As the main source of E. coli will be from sewage effluent, it is considered that the construction activities and the intermediate layout of the proposed reclamation will not be the main factor of the local elevation of E. coli.
10.6.3.4.6                Overall, under wet season conditions, water quality for the Intermediate Layout generally shows little change compared Baseline conditions with no serious deterioration in any temporary water bodies created.  It indicates that in the context of high levels of pollution in Victoria Harbour, pollution caused by the construction of the proposed reclamation will be negligible.  It is also noted that relocation of Outfall J1 to Outfall J at this phase of the works results in significant improvements to water quality.

10.6.3.5            Floating Debris

Simulation

10.6.3.5.1                Simulations of floating rubbish were carried out to determine whether the intermediate layout of the proposed reclamation would cause floating rubbish to be trapped, particularly in the water body formed between the Initial Area East, the Initial Area West and the existing coastline.
10.6.3.5.2                The likelihood of accumulations of floating rubbish occurring in the embayment created by the Intermediate Layout reclamation was assessed using the TELEMAC-3D results.  The embayment was seeded with an even distribution of floating particles, and the trajectories of the particles were simulated over the 25-hour wet season neap tide sequence, to provide indications of the flushing of the embayment for the tide type on which flushing is likely to be least.  Simulations were carried out for initial particle distributions at HW and LW slack.

Impacts

10.6.3.5.3                The distributions of floating particles in the embayment at various times through the tidal sequence are shown in Figures 2.9a and 2.9b in Appendix O for the simulations starting at LW and HW.  The numbers of particles within the embayment decrease gradually throughout the simulations but, after 25 hours, 24% and 28% of the particles remain within the embayment for the simulations initiated at LW and HW respectively.  This indicates that, for the tide type simulated, there would be a tendency for some quantities of floating rubbish to be retained within the embayment for periods of the order of several days.  Mitigation measures are suggested in section 10.6.4.4 to minimise the impact of floating debris.

10.6.4                            Mitigation Requirements

10.6.4.1            Construction Design

10.6.4.1.1                The water quality impact during the construction phase was assessed on the basis of the reclamation design layout proposed at the time when the water quality modelling was conducted. The reclamation, which includes the construction of the western arm (Initial Reclamation Area West) and the eastern land projection (Initial Reclamation Area East) , has been revised (from the CRIII Preliminary Project Feasibility Study (PPFS) design) to avoid the formation of a temporary embayed area and enhance water movement and seawater flushing of the temporarily formed water body. The design is also aimed at minimising the impact of SS on the cooling/flushing water intakes at the existing Central coastline,  with the culverts and water intakes reprovisioned before the beginning of the near-shore reclamation near the existing facilities.

10.6.4.2            Dredging

10.6.4.2.1                                                                                                                                                                                                                                         Although the predicted SS increase generated from dredging would be acceptable at the cooling water and flushing water intakes, the contractor should introduce practical mitigation measures to minimise the local and far-field impact of SS. These mitigation measures include:

·                the use of closed clamshell (water-tight) grab dredgers to remove seriously contaminated material such that the amount of SS and other pollutants released from the marine mud and pore water can be minimised;

·                the prohibition of stockpiling of any moderately or seriously contaminated marine sediment, and careful control of stockpiling of any uncontaminated sediment to prevent runoff, resuspension and odour nuisances; and

·                the control of dredging and bulk reclamation filling rates within acceptable limits.  Based upon the construction sequence developed for this study the maximum dredging and filling rates adopted for Final Reclamation Area East were :

Maximum Dredging Rate                   :        184 m2/hour

Maximum Daily Filling Rate                :        17,727 m3/day
(for bulk reclamation filling)

For details of working rates assumed for other reclamation areas, that are considered to be less critical, refer to Table 10.14.

These rates could be included as a mitigation measure on the provision that they are accompanied by a statement to indicate that they are based upon an assumed construction method.  Should this method be varied for any reason, re-assessment may be necessary to confirm compliance with WQOs.

10.6.4.2.2                Carefully designed silt curtains can be an effective means of preventing dispersion of suspended sediment from dredging operations.  However, previous experience has shown that in general the use of silt curtains around dredging sites jeopardise the navigation of ships and ferries along the ferry channels. Given the considerable amount of marine traffic in and around the CRIII area, the use of silt curtains to contain silt plumes from CRIII dredging would be difficult but not impossible to implement.  It is, however, considered that framed geotextile fabric silt screens that are installed at the opening of the intakes (and have been used in CRI) could be deployed to protect cooling water intakes and reduce the impact of dredging works.   The use of silt screens would also be ground practice given the nature of the intakes in the surrounding areas.  This local protection measure deployed for CRI works, has been shown to be an effective local mitigation measure. The maintenance of the silt screens, if used, would need to be carried out frequently (at least once a day) to remove the rubbish and any large substances that block the screen and also check the integrity of the silt screens. The maintenance work of the silt screens installed at the intakes may be carried out by a maintenance vessel in the evening to avoid interruption of the busy daytime ferry traffic.
10.6.4.2.3                Wind surging effect on currents are very considerable under strong monsoon winds, severe convective or frontal storms, or typhoons. No dredging should therefore take place under very bad weather conditions.

10.6.4.3            Marine Disposal of Dredged Materials and Marine Sand Filling

10.6.4.3.1                The following measures have been identified to minimise potential impacts on water quality arising during marine transportation of the dredged material and marine sand filling:

·                all vessels should be sized such that adequate clearance is maintained between vessels and the sea bed at all states of the tide to ensure that undue turbidity is not generated by turbulence from vessel movement or propeller wash;

·                all hopper barges and dredgers should be fitted with tight fitting seals to their bottom openings to prevent leakage of material;

·                loading of hopper barges should be controlled to prevent splashing of dredged or filling material to the surrounding water, and barges or hoppers should not be filled to a level which will cause the overflow of materials or polluted water during loading or transportation;

·                the works should cause no visible foam, oil, grease, scum, litter or other objectionable matter to be present on the water within the site or dumping grounds;

·                bulk filling should be carried out, where feasible, behind completed seawall to above high water mark.  In general and where physically practical, filling should not be carried out without the seawall having been substantially completed for a distance of 100m – 200m ahead of filling; and

·                fill materials should comply with technical specification requirements and be taken from approved sources only.  The maximum fines content of marine sand should be limited to 5% as assumed in the water quality assessments.

10.6.4.3.2                In order to complete this study under, its current Brief, the EIA has been completed on the basis that the New Sediment Quality Management Framewok would not apply, but that an earlier Sediment Quality Study for the site conducted in 1996 would be utilised (refer also to Section 3.8.6.4).  Additional provisions will be required where dredged sediments are contaminated. The locations and depths of any areas of contaminated sediments should be indicated in the construction contract.  The Contractor should be required to ensure that contaminated sediments are dredged, transported and placed in approved special dumping grounds in accordance with the newly issued WBTC 3/2000 and WBTC No. 12/2000 and the earlier WBTC No. 6/92 and in accordance with dumping permit conditions provided by EPD/MFC. Typical mitigation measures to minimise the loss of contaminated material to the water column are listed below. Most of them are also applicable to the transportation of filling material.

·                transport of contaminated mud (or filling material) to the marine disposal site (or works site) should, wherever possible, be by split barge of not less than 750 m3 capacity, well maintained and capable of rapid opening and discharge at the disposal site;

·                the dredged material should be disposed in the pit by bottom dumping, at a location within the pit specified by the MFC;

·                discharge should be undertaken rapidly and the hoppers should then immediately be closed. Material adhering to the sides of the hopper should not be washed out of the hopper and the hopper should remain closed until the barge next return to the disposal site;

·                the dumping vessel is not required to station but will be guided by the site staff managing the disposal facility.  The vessel crew should be familiar with such operational procedures;

·                monitoring of the barge loading to ensure that loss of material does not take place during transportation; and

·                transport barges or vessels shall be equipped with automatic self-monitoring devices.

10.6.4.4            Floating Debris

10.6.4.4.1                The result of the floating debris simulation has shown that the intermediate layout of the proposed reclamation has potential to trap floating rubbish. Monitoring and control of the construction activities should be taken to prevent the release of construction waste and rubbish from the construction site. Collection of floating debris should be carried out at least once every day by the CRIII Contractor, and more frequently (two or three times per day) at the water body south of the Initial Reclamation Area West and near the cooling water intakes where large substances could block the screens and filter pipes of the intakes and reduce their efficiency. Debris should be collected and taken to landfill sites for disposal.

10.6.4.5            Management of Marine Spoil Disposal

10.6.4.5.1                The excavated material dredged during reclamation and seawall construction will be dumped off-site. The total amount of excavated material will be approximately 580 000 m3, with estimated maximum rates of about 1,035 m3 per day of Class A uncontaminated mud, about 60 m3 per day of Class B moderately contaminated mud and about 1,850 m3 per day of Class C highly contaminated mud. Based on the EPDTC No,. 1-1-92 disposal should be as follows

·                Uncontaminated (Class A) and contaminated (Class B) mud disposal sites include the open sea disposal areas at South Cheung Chau and East Ninepins, and empty marine borrow pits (for example, North of Lantau, South Tsing Yi and East Tung Lung Chau)

·                Contaminated (Class C) mud disposal facility is located at East Sha Chau

·                Hopper barges will be used to transport the dredged marine sediment to the designated dumping area.

It is noted that the newly issued WBTC 3/2000 has somewhat modified the permitted disposal sites for dredged materials.  An assessment of the requirements for the new WBTC has been carried out using  the test data collected for the Sediment Quality Study conducted in 1996 and concluded that the above disposal sites would still apply.  This assessment will, however, be confirmed by the ongoing Sediment Quality Studies for the CRIII Minimum Option (refer also to paragraph 3.8.6.4).

10.6.4.5.2                In all cases, EPD will advise on the most appropriate disposal method for the material. Any environmental conditions to be imposed with the dumping licence and special disposal arrangements will be specified at this time. The MFC will finalise and stipulate the disposal allocation of any volume of contaminated sediment. Any further conditions relating to the management of the disposal area will also be specified at this time.
10.6.4.5.3                For seriously contaminated sediments, special disposal arrangements comprising contained disposal in designated marine pits will be necessary. The only disposal site at present designated for the disposal of contaminated muds comprises the East Sha Chau CMPS. The Contractor should ensure that all dredging and disposal methods are in compliance with the environmental conditions imposed under the terms and conditions of EPD's marine dumping permit. Specific dredging procedures, which are required to minimise any potential water quality impacts, should be included in the contract documents.

10.6.4.6            Cumulative Assessment of Central Reclamation Phase III and Wan Chai Development Phase II Construction Works

10.6.4.6.1                At the time the CRIII water quality modelling was undertaken, the combined effects of the CRIII and WDII works were not considered due to a lack of information on the WDII works.  The WDII water quality modelling has, however, considered the combined effects of the CRIII and WDII works in addition to the Yau Tong works all of which would be in progress at the same time.
10.6.4.6.2                The predicted mitigated cumulative SS levels for the three project construction works are presented in Table 10.28 below.  More detailed information on the modelling works undertaken to produce these results are provided in Appendix Q of this report and also in Reference 8.

Table 10.28 : Predicted SS Levels for Cumulative Scenario at the Seawater Intakes after the Implementation of Mitigation Measures

Sensitive Receiver

SS concentration (absolute value) in surface layer (mg L-1)

 

 

Dry season

Wet season

 

Criterion

Maximum (1)

Maximum (1)

Cooling Water Intakes

 

 

 

Windsor House

-

5.3

25.4

Excelsior Hotel & World Trade Centre

-

4.3

7.3

Sun Hung Kai Centre

-

11.6

10.3

Great Eagle Centre / China Resources Building

-

8.7

8.0

Wan Chai Tower / Revenue Tower / Immigration Tower

-

8.7

8.0

Hong Kong Convention and Exhibition Centre Phase I

-

28.3

7.1

Hong Kong Convention and Exhibition Centre Extension

-

6.2

6.6

Telecom House / HK Academy for Performing Arts / Shun On Centre

-

15.1

9.5

MTRC South Intake

< 40

15.1

9.5

Prince's Building Group at CRIII

-

6.7

4.9

Queensway Government Offices at CRIII

-

20.1

28.0

Admiralty Centre at CRIII

< 40

20.1

28.0

HSBC & Hotel Furama at CRIII

-

5.0

15.8

WSD Saltwater Intakes

 

 

 

Wan Chai

< 10

6.1

4.9

Central Water Front

< 10

4.3

7.0

Sheung Wan

< 10

4.5

6.0

Quarry Bay (2)

< 10

4.3

7.0

Kennedy Town

< 10

3.7

2.4

Sai Wan Ho

< 10

3.6

8.1

 

Notes:

(1)      Absolute value of SS includes the ambient SS level (7.5 mg L-1 for dry season and 5.8 mg L-1 for wet season) in the surface layer of water column.

(2)      As the invert level of the intake is located at the second top layer of the water column, the SS levels at the second top layer are quoted.

10.6.4.6.3                The mitigation measures applied to the CRIII works to produce the SS levels presented in Table 10.28 were:

·                deployment of silt curtains around the dredging and fill release points to contain SS within the construction site during dredging and filling;

·                deployment of silt screens at the cooling water intakes and WSD salt water intakes to further minimise the intake of SS within the sea water.

It is therefore concluded that should the CRIII and WDII dredging and filling works be occuring simultaneously that these measures should be applied by the CRIII contractor.

10.6.5                            Construction Water Quality Impacts from Site Runoff

10.6.5.1            Introduction

10.6.5.1.1                The impacts of construction activities on water quality will result mainly from sediment loaded site runoff and drainage (including groundwater from tunnel works) and sewage from on-site construction workforce. During the construction phase, the site effluents will be discharged to the marine waters of Victoria Harbour.
10.6.5.1.2                All such activities will be controlled by the Water Pollution Control Ordinance (WPCO) in as much as they may give rise to effluents.  Discharge of liquid runoff from the site will need to comply with the requirements in the relevant Technical Memorandum for the Water Control Zone.  Sewage arising will need to be directed to the nearest sewer and comply with the Standards for Effluents Discharged to Drainage and Sewerage Systems, Inland and Coastal Waters.

10.6.5.2            Construction Run-off and Drainage

10.6.5.2.1                Construction site run-off during the phased reclamation may contain increased concentrations of suspended solids (SS), increased sediment loads and other site contaminants. Potential sources of pollution include:

·                run-off and erosion from site surfaces, drainage channels, earthworks or stockpiles;

·                bentonite slurries and other grouting materials;

·                concrete production washout and drainage from dust suppression sprays; and

·                fuel, oil and lubricants from construction equipment.

10.6.5.2.2                The presence of increased SS in the water column as a result of site run-off will reduce light intensity and depth of penetration, reducing photosynthesis and further reducing DO content in lower water level.
10.6.5.2.3                Run-off containing significant quantities of concrete and cement derived materials, bentonite slurry and grouting material may have a chemical impact upon local coastal waters. Local increases in turbidity, discoloration and pH may occur. These may result in secondary impacts including toxic effects to marine organisms as a result of increased pH, reduced decay rates of faecal micro organisms due to reduced light penetration, and an increase in the local levels of un-ionized ammonia.

10.6.5.3            General Construction Activities

10.6.5.3.1                Site activities have the potential to cause water pollution as a result of improper disposal and site practices. Site waste materials such as packaging, used materials and general waste, as well as spillage of oil, diesel or solvent will have either a negative aesthetic or chemical impact upon water quality.

10.6.5.4            Sewage Effluent

10.6.5.4.1                Suitable facilities will need to be provided for the disposal of worker generated sewerage. The scale of the works is such that the use of chemical toilets should be adequate.

10.6.5.5            Specific Water Quality Impacts

10.6.5.5.1                The extent of water quality impact will depend largely on the selected construction method and distance from sensitive receivers.

The potential impacts of the different construction methods are discussed below:

·                Cut and Cover Tunnels (CWB, EOT and NIL Protection Works)

This construction method requires an open site for the majority of the construction period. During this period, run-off containing high levels of silt or SS may be generated by heavy rainfall, and may also be contaminated by grout. As described above, these inputs into marine waters or drainage facilities would have a detrimental effect upon water quality and would consequently require the implementation of suitable mitigation measures. The construction of diaphragm walls will require the use of bentonite. It is strongly recommended that construction uses  a method whereby the spoil is cut from the wall excavation and pumped to the surface. The spoil/bentonite mixture is then separated in a sealed system with the bentonite being re-circulated and the spoil loaded on to trucks for disposal. The alternative option of using a grab could lead to bentonite reaching the drainage system.

·                Excavation and Demolition Material Storage and Handling

Construction will generate a large quantity of material, some of which may be stored on site prior to use as backfilling material. The cut and cover method has the potential to cause the greatest impact. Appropriate measures are therefore required to ensure that run-off from any stockpiling activity is reduced to acceptable levels.

·                Ventilation Shaft Construction

The construction of ventilation shaft facilities may require the use of grout, which as described above, has the potential to affect marine water quality. Suitable mitigation measures would reduce this impact to a negligible level.

10.6.5.6            Construction Stage Mitigation Measures

ProPECC PN 1/94 recommends various site practices which should be followed, where applicable, to mitigate against water quality deterioration. Relevant measures are summarised below:

·                Control of Site Surface Runoff:

-    Surface run-off from construction sites should be discharged into storm drains via adequately designed sand/silt removal facilities such as sand traps, silt traps and sediment basins. Channels or earth bunds or sand bag barriers should be provided on site to properly direct stormwater to such silt removal facilities. Perimeter channels at site boundaries should be provided where necessary. Catchpits and perimeter channels should be constructed in advance of site formation works and earthworks.

-    Silt removal facilities, channels and manholes should be maintained.

-    Construction works should be programmed to minimise soil excavation works in rainy seasons (April to September). If excavation in soil cannot be avoided, temporarily exposed slope surfaces should be covered and temporary access roads should be protected by crushed stone or gravel, as excavation proceeds. Intercepting channels should be provided.

-    Earthworks final surfaces should be well compacted and the subsequent permanent work or surface protection should be carried out immediately after the final surfaces are formed to prevent erosion caused by rainstorms. Appropriate drainage such as intercepting channels should be provided where necessary.

-    Measures should be taken to minimise the ingress of rainwater into trenches. If excavation of trenches in wet seasons is necessary, they should be dug and backfilled in short sections. Rainwater pumped out from trenches or foundation excavations should be discharged into storm drains via silt removal facilities.

-    Open stockpiles of construction materials should be covered.

-    Manholes should be adequately covered and temporarily sealed.

·                Groundwater

-    Groundwater pumped out of tunnels or caverns should be discharged into storm drains after the removal of silt.

·                Boring and Drilling Water

-    Water used in ground boring and drilling for site investigation or rock/soil anchoring should as far as practicable be recirculated after sedimentation. Wastewater should be discharged into storm drains via silt removal facilities.

·                Wastewater from Concrete Batching and Precast Concrete Casting

-    Wastewater generated from the washing down of mixer trucks and drum mixers and similar equipment should wherever practicable be recycled. The discharge of wastewater should be kept to a minimum.

-    To prevent pollution from wastewater overflow, the pump sump of any water recycling system should be provided with an on-line standby pump of adequate capacity and with automatic alternating devices.

-    Under normal circumstances, surplus wastewater may be discharged into foul sewers after treatment in silt removal and pH adjustment facilities (to within the pH range of 6 to 10). Disposal of wastewater into storm drains will require more elaborate treatment. Surface run-off should be segregated from the concrete mixing and casting yard area as much as possible, and diverted to the stormwater drainage system. Surface run-off contaminated by materials in a concrete mixing area or casting yard should be adequately treated before disposal into stormwater drains.

·                Wheel Washing Water

-    All vehicles and plant should be cleaned before they leave the construction site. A wheel washing bay should be provided at every site exit if practicable and wash-water should have sand and silt settled out or removed before discharging into storm drains. The section of construction road between the wheel washing bay and the public road should be paved with backfall to reduce vehicle tracking of soil and to prevent site run-off from entering public road drains.

·                Bentonite Slurries

-    Bentonite slurries should be reconditioned and reused wherever practicable. If the disposal of a certain residual quantity cannot be avoided, the used slurry may be disposed of at the marine spoil site subject to obtaining a marine dumping licence from EPD (on a case-by-case basis).

-    If the used bentonite slurry is intended to be disposed of through the public drainage system, it should be treated to the respective effluent standards applicable to foul sewers, storm drains or the receiving waters as set out in the WPCO Technical Memorandum on Effluent Standards.

·                Wastewater from Building Construction

-    Before commencing any demolition works, all sewer and drainage connections should be sealed to prevent building debris, soil, sand etc. from entering public sewers/drains.

-    Wastewater generated from building construction activities including concreting, plastering, internal decoration, cleaning of works and similar activities should not be discharged into the stormwater drainage system. If the wastewater is to be discharged into foul sewers, it should undergo the removal of settleable solids in a silt removal facility, and pH adjustment as necessary.

·                Wastewater from Site Facilities

-    Sewage from toilets, kitchens and similar facilities should be discharged into a foul sewer. Chemical toilets may used as an alternative.

-    Wastewater collected from canteen kitchens, including that from basins, sinks and floor drains, should be discharged into foul sewers via grease traps capable of providing at least 20 minutes retention during peak flow.

-    Drainage serving an open oil filling point should be connected to storm drains via a petrol interceptor with peak storm bypass.

-    Vehicle and plant servicing areas, vehicle wash bays and lubrication bays should as far as possible be located within roofed areas. The drainage in these covered areas should be connected to foul sewers via a petrol interceptor. Oil leakage or spillage should be contained and cleaned up immediately. Waste oil should be collected and stored for recycling or disposal in accordance with the Waste Disposal Ordinance.

·                Licensing of Construction Site Discharges within Water Control Zones

-    All discharges into any drainage or sewerage systems, or inland or coastal waters, or into the ground (e.g. from septic tanks) within a Water Control Zone are controlled under the Water Pollution control Ordinance (WPCO), except the discharge of domestic sewage into foul sewers or the discharge of unpolluted water into storm drains or into the waters of Hong Kong. Construction site discharges are controlled under the WPCO.

-    Discharges controlled under the WPCO must comply with the terms and conditions of a valid WPCO licence.

10.6.6                            Monitoring and Audit

10.6.6.1            Based on the above assessments of the water quality impact, an environmental monitoring and audit (EM&A) programme is considered necessary to obtain a robust, defensible database of baseline information of water quality before the construction, and thereafter, to monitor any variation of water quality from the baseline conditions during construction. This is particularly the case during the period when dredging and filling are carried out simultaneously. The EM&A Manual for the CRIII works will be produced as a separate stand-alone document.

10.7                                  Operation Phase Impact Assessment

10.7.1                            Introduction

10.7.1.1            The impacts on the water quality, within the CRIII EIA report, has not included the impacts associated with the Wan Chai Development Phase II (WDII) reclamation works.  The CRIII water quality modelling was undertaken in this manner due to lack information on the WDII works at the time of the CRIII water quality modelling.  However, water quality modelling has now been completed by the WDII Consultant and cumulative assessments as applicable to the CRIII and WDII projects provided by the WDII Consultant are included in Section 10.7.7 and Appendix Q of this EIA Report.

10.7.1.2            The completion of CRIII may result in changes to water quality impacts as a result of changes to water movement patterns and tidal flushing rates.  The temporary slack water to the east of CRIII will be removed by WDII when the coastline of the water basin will be smoothened and the extension of culvert L will be treated as a matter of urgency.

10.7.1.3            The reclamation layout following CRIII construction only was included in the model mesh, and the hydrodynamic and water quality models were run for dry and wet season conditions, using the same boundary and initial conditions as the equivalent Baseline and Intermediate simulations.  No other changes to the coastline configuration were made.  At the time of modelling no information was available in respect of the Wan Chai Development Phase II project.  The Feasibility Study for that project only commenced in mid 1999.  The mesh used for this Final Scenario is illustrated in Figure 3.1 in Appendix O.  In areas outside the reclamation, sea bed depths were unchanged from the Baseline and Intermediate Scenarios.

10.7.1.4            The modelling output for the Operational Layout is presented both in graphical and tabular format in Appendix O.  The extent of the geographical area presented in the graphical output was carefully selected to provide maximum detail for the region where changes were found to occur when compared to the Baseline Layout output.  At the boundaries of the graphical plots it can be seen that only very minor differences, if any, are present between Operational and Baseline Layouts.  The quantitative magnitudes of these changes for sensitive receivers outside the extent of the graphical plots is confirmed by the information contained in the tables.

10.7.2                            Baseline Conditions

10.7.2.1            After gazettal of the Victoria Harbour WPCO in April 1996, all effluent discharges are subject to statutory control. In addition to this, the implementation of the SSDS will mean that in future there should be an improvement in the water quality of Victoria Harbour when compared to the existing conditions.

10.7.3                            Water Movement

10.7.3.1            Figures 3.2a and 3.2b in Appendix O show the simulated surface flow patterns in the study area for spring and neap tides in the wet season.  Contour plots of simulated maximum speeds for the same tides at the sea surface and sea bed are shown in Figures 3.3a and 3.3b in Appendix O.  Equivalent results for the dry season are shown in Figures 3.4a – 3.4b and 3.5a – 3.5b in Appendix O.

10.7.3.2            Comparison with the equivalent figures for the Baseline simulations (Figures 1.2a to 1.5b in Appendix O) indicates that the reclamation causes little change in the prevailing currents and, outside the immediate vicinity of the works, the flows through Victoria Harbour are virtually unaffected by the reclamation.  Within the reclaimed area, a slight reduction in current speeds is evident between the east face of the reclamation and the HKCEC, as expected given the restricting effect of the works, but this change is localised.

10.7.3.3            In order to assess the impact of the CRIII reclamation works on the overall flushing capability of the harbour and Hong Kong Waters, a quantitative comparison of the changes of discharge rates at a section to the east and a section to the west of the CRIII area has been undertaken.  The locations of these sections are presented in Figure 10.24 and the results included in Table 10.29.

 

Table 10.29  : Comparison of discharge rates at Sections to the East & West
of the CRIII Area

 

Dry season spring tide

 

 

Maximum Discharge
% change from Baseline

Average Discharge
% change from Baseline

Inter-mediate

Final

Inter-mediate

Final

Section 1 (Refer to Figure 10.24)

Flood

-

0.3

-

0.4

Ebb

-

0.3

-

0.3

Section 2 (Refer to Figure 10.24)

Flood

-

0.2

-

0.2

Ebb

-

0.1

-

0.0

Dry season neap tide

Section 1 (Refer to Figure 10.24)

Flood

-

0.1

-

0.2

Ebb

-

0.3

-

0.2

Section 2 (Refer to Figure 10.24)

Flood

-

0.0

-

0.1

Ebb

-

0.0

-

-0.1

Wet season spring tide

Section 1 (Refer to Figure 10.24)

Flood

0.1

0.2

0.0

0.3

Ebb

0.2

0.4

0.1

0.3

Section 2 (Refer to Figure 10.24)

Flood

0.1

0.2

-0.1

-0.1

Ebb

0.2

0.1

0.1

0.1

Wet season neap tide

Section 1 (Refer to Figure 10.24)

Flood

0.0

0.2

0.0

0.2

Ebb

0.3

0.5

0.2

0.4

Section 2 (Refer to Figure 10.24)

Flood

0.0

0.1

0.0

0.0

Ebb

0.2

0.3

0.1

0.1

10.7.3.4            Table 10.29 shows the percentage change in the maximum and average flood and ebb tide discharges through the two sections shown in Figure 10.24 for each combination of season, tide type and reclamation layout tested when compared to the baseline conditions. The average discharge is the mean of all the discharges simulated in the relevant direction of flow, over the approximately diurnal cycles used for analysis of each tide type.

10.7.3.5            All of the discharge changes predicted to result from the Central Reclamation Phase III development are extremely small; being less than 0.5% of the discharges in the Baseline Scenario.  This indicates that net flows through Victoria Harbour are unlikely to be changed significantly by the CRIII reclamation, and that flow changes elsewhere in Hong Kong waters will be negligible.

10.7.3.6            In general, the simulated discharges are increased marginally during and after the construction, with changes from the Baseline being larger after construction than during construction.  With such small effects, it is difficult to attribute changes to specific causes, but it is likely that the increases are due to the flow through Victoria Harbour being diverted into deeper areas, on average, by the presence of the reclamation; consequently being subject to less friction at the sea bed.  It is not clear why marginal reductions in average discharge are simulated for two conditions (dry season neap tide ebb flow and wet season spring tide flood flow), but these may be due to slight adjustments in the phases of currents across parts of the sections.

10.7.4                            Water Quality

10.7.4.1            Pollutant Loads

10.7.4.1.1                Loadings of water quality parameters used for the Final Scenario were similar to those used for the Intermediate Scenario, except for further relocations of some culverts necessitated by the presence of the reclamation and scaling up of some culvert flows as now described.  Stormwater outfall I is connected into stormwater Culvert F in the new reclamation area and hence its flow is directed through stormwater outfall F.  For the operational phase the flow through the stormwater culverts, (and outfalls) have been increased from the baseline flows to account for additional run off from the new reclamation area.  The increase in flows are 10% for Culverts J and K and 50% for Culvert F and are based upon stromwater drainage modelling output from the Comprehensive Feasibility Study for Minimum Option.  It was anticipated that the relocation of most of the stormwater culverts into areas of increased current speeds would enhance pollutant dispersion.  Details of the stormwater culverts used in the Final Scenario are summarised in Tables 10.30 and 10.31 and illustrated on Figure 10.25.

Table 10.30 :  Locations and discharges of the stormwater outfalls near Central during the operational phase

Location Name

Easting

Northing

Volume

m3/day

Stormwater outfall K

835450

816014

1,673

Stormwater outfall F

834905

816150

6,815

Stormwater outfall J

835076

816077

10,654

Stormwater outfall L

835440

815845

1,166

Table 10.31 :  Water quality variable loads for the stormwater outfalls near Central during the operational phase

Location Name

BOD5

kg/day

TKN

kg/day

NH3-N

kg/day

E-coli

counts/day

Stormwater outfall K

31.8

4.8

4.8

6.78E+13

Stormwater outfall F

945.0

227.3

92.3

7.72E+14

Stormwater outfall J

2758.9

454.3

322.0

2.95E+15

Stormwater outfall L

304.3

17.5

17.5

7.93E+14

 

10.7.4.2            Impacts

Wet Season Results

10.7.4.2.1                The results of the wet season Final Layout water quality simulations are presented in Figures 3.6a to 3.9b in Appendix O.
10.7.4.2.2                The overall distributions of DO (Figures 3.6a to 3.6c in Appendix O) are largely unchanged from the Baseline simulation (Figures 1.6 a to 1.6c in Appendix O).  At the surface during the spring tide, DO values were below 6.7mgl-1 in the Baseline (Figure 1.6a in Appendix O) in the embayment to the east of the Central Phase I reclamation, but the presence of the CRIII reclamation restricts values in this range to a localised zone near the relocated outfall F (Figures 3.6a in Appendix O).  This is largely due to the relocation of the outfall into a zone of higher current speeds and, therefore, increased dispersion.  There is no indication that the reclamation will create any poorly flushed areas with reduced dissolved oxygen concentrations.
10.7.4.2.3                The distributions of BOD5 are little changed by the presence of CRIII when compared to the baseline conditions. (Figures 1.7a and 1.7b and 3.7a and 3.7b in Appendix O).  Whereas BOD5 concentrations greater than 2.0 mgl-1 occurred near outfalls F, I and J1 in the Baseline simulations (Figures 1.7a and 1.7b in Appendix O), concentrations in this range are restricted to localised zones near the relocated outfalls (Figures 3.7a and 3.7b in Appendix O).  Sewerage improvement works planned by DSD as part of the CW3 Trunk Sewer Contract will reduce pollution loads from culverts F and J1.  The extent and nature of these works was determined following field surveys to identify locations where pollutant loadings enter the stormwater system.  The works will therefore result in large reductions to the pollutant loads discharging from Culverts F and J1.  The presence of the reclamation creates a zone of relatively slack water around outfall L, in the corner between the east face of CRIII and the existing coastline, but elevated BOD5 concentrations (>2 mgl-1) are localised in the vicinity of this outfall.  Although the predicted levels of BOD5 around outfalls are higher than the range of the BOD5 concentration measured by the EPD’s VM5 water quality monitoring station, it is likely that the future water quality conditions in the Victoria Harbour will improve due to the progressive implementation of various Government pollution abatement measures including Stage 1 (and subsequent stages) of SSDS, Central Western and Wanchai West Sewerage Scheme and the gazettal of the final phase of Victoria Harbour WCZ.  Any local elevation of BOD5 concentration due to the proposed reclamation should not be worse than the model predicted BOD5 levels.
10.7.4.2.4                Changes in unionised ammoniacal nitrogen and total inorganic nitrogen concentrations associated with CRIII when compared to the Baseline conditions (Figures 1.8a – 1.8f and 3.8a to 3.8f in Appendix O) are qualitatively similar to changes in BOD5 concentrations. It is considered that the Wanchai sewage outfalls would be the main sources of ammoniacal nitrogen over the study area and the final layout of the proposed reclamation should not cause any accumulation of ammoniacal nitrogen near the reclamation.
10.7.4.2.5                Changes in E. coli concentrations associated with CRIII when compared to the Baseline conditions (Figures 1.9a – 1.9b and 3.9a - 3.9b in Appendix O) are qualitatively similar to changes in BOD5 concentrations.  The creation of the zone of relatively slack water around outfall L is evident in the E. coli concentration fields as an expansion of the area with concentrations in excess of 1x105counts/100ml at the sea surface, but this area remains localised.  Cooling water pumping station intakes located near to culvert L outfall do not have any criteria for E.coli levels and therefore will not be adversely affected by the local increases.  It should be noted that the Wanchai sewage outfalls would be the major source of E.coli in the general area and the final layout of the proposed reclamation should not cause any local elevation of the bacterial level with the exception of a local area around Culvert L outfall.  The embayment will last for some 20 months from the construction of the CRIII seawall in May 2005 until the reclamation of the adjacent area under the WDII project in January 2007.  The delay in filling of this embayment arises due to the restriction of piling, dredging and reclamation works in the vicinity of the existing cross harbour water mains, which must be diverted first before any disturbance of the seabed in this area can take place.  As a mitigation measure, to avoid the accumulation of water borne pollutants within this embayment, an impermeable barrier, suspended from a floating boom on the water surface and extending down to the seabed, will be erected by the CRIII Contractor on completion of the CRIII eastern seawall. The barrier will channel the stormwater discharge flows from Culvert L to the outside of the embayment.  The CRIII Contractor will maintain this barrier until the WDII Contractor takes possession of this site, whereupon the WDII Contractor will takeover the maintenance of this barrier until the reclamation works in this area are carried out and the new Culvert L extension is constructed.

Dry Season Results

10.7.4.2.6                The results of the dry season Final Layout water quality simulations are presented in Figures 3.10a to 3.13b in Appendix O.
10.7.4.2.7                The changes associated with the Final Layout relative to the Baseline (Figures 1.10a to 1.13b in Appendix O) are qualitatively similar to those indicated by the wet season simulations, that is, the areas of the zones of elevated pollutants concentrations around outfalls F, I and J1 in the Baseline have been significantly reduced by the relocations of the outfalls into area of relatively high dispersion, and by the removal of the embayment where these discharges were situated previously.  This pattern of change is reversed at outfall L, where the slack water zone created by the reclamation results in an expanded area of elevated pollutant concentrations.  However, the effects of the outfall remain localised. Cooling water pumping station intakes located near to culvert L outfall do not have any criteria for E.coli levels and therefore will not be adversely affected by the local increases.  At this location it is also noted that the existing Wanchai sewage outfalls would be the main source of pollutants in the general area and the final layout of the proposed reclamation should not cause any local elevation of pollutants near the reclamation with the exception of a local area around Culvert L outfall.  The proposed mitigation measure for dealing with potential accumulations of water borne pollutants within this area is described in paragraph 10.7.4.2.5 above.

10.7.5                            Floating Refuse and Debris

10.7.5.1            Modelling Simulations

10.7.5.1.1                The likelihood of accumulations of floating rubbish occurring in the partial embayment created between the Final Layout reclamation and the HKCEC (assuming that the further proposed reclamation to the east (associated with the WDII project) had not been completed at that time) was assessed using the TELEMAC-3D results.  The embayment was seeded with an even distribution of floating particles, and the trajectories of the particles were simulated over the 25-hour wet and dry season neap tide sequences, to provide indications of the flushing of the embayment for the tide types on which flushing is likely to be least.  Simulations were carried out for initial particle distributions at HW and LW slack for both tide types.

10.7.5.2            Results

10.7.5.2.1                The distributions of floating particles around the reclamation limit  at various times through the tidal sequences are shown in Figures 3.16a - 3.17b in Appendix O for the wet and dry seasons.  The number of floating particles around the reclamation decreases rapidly in the four simulations and, after 25 hours, less than 0.5% of the released particles remain in all cases.  This indicates that accumulations of floating rubbish are unlikely to persist in this area following the construction of the reclamation.  Mitigation measures are, however, proposed in Section 10.7.8 to deal with any trapped debris which may accumulate particularly in the area between the HKCEC and the eastern limit of the reclamation until the completion the WDII works in this area.

10.7.6                            Operational Water Quality Impacts from Runoff

10.7.6.1            Surface run-off from roads can contain materials such oils, tyre rubber, grit and metals.  The ‘first-flush’ run-off from a storm may have potential to cause impacts, particularly after a dry period.  After the first-flush, the run-off will become diluted.  There is little research data available on this subject in Hong Kong.  International research undertaken by the OEDC (1994), ‘Environmental Impact Assessment of Roads, 1994’, highlights that there is no practical way to predict road runoff contamination as this is dependent on storm characteristics (duration, intensity, periods between storms), and in addition, the characteristics of the vehicles using the road.  The research concluded that the ‘observed [pollutant] concentrations at any site can be treated as random variables having a lognormal probability distribution’.

10.7.6.2            Within the framework of the CRIII project, it is not possible to conclude that the runoff should be treated.  However, consideration will need to be given to locating discharge points away from any sensitive locations identified in the future and the provision of grit traps.  Tunnel discharges should be fitted with oil traps / petrol interceptors.

10.7.7                            Cumulative Impacts on the Harbour Hydrodynamics

10.7.7.1            The model studies indicate that the effects of CRIII on flows and water quality in Victoria Harbour will be localised.  Overall, the distributions of water quality parameters are predicted to be little changed by the reclamation.

10.7.7.2            At the commencement of the study, a cause of concern was that the temporary and permanent embayments created by the reclamation may result in significant deterioration of the prevailing water quality.  The embayment created during the construction phase, adjacent to the Central Phase I reclamation, is predicted to cause small reductions in dissolved oxygen levels, but the impounding effect of the embayment on water quality should be offset, to a large extent, by the relocation of stormwater Outfall J1.  However, accumulations of floating rubbish could occur within this embayment.  On completion of the works, a partial embayment may be created between CRIII and the HKCEC depending on the status of construction works on the adjacent WDII project.  Studies, however, indicate that floating rubbish will not tend to accumulate at this location.

10.7.7.3            This study has considered the CRIII works in isolation of other reclamation and pollutant source relocation in Victoria Harbour.  The Wan Chai Development Phase II project EIA Study operation phase scenario ( in year 2012) considers the water quality impact of CRIII cumulatively with all other developments planned to take place in Victoria Harbour by 2012.  The details of this cumulative assessment are presented in Appendix Q.  The key conclusions of the assessment were:

·                The wet season ebb tide flow speeds in the Victoria Harbour are higher than that in the dry season.  For the flood tide simulations, the flow speeds are more comparable between the two seasons.

·                The flow speed distributions within the Victoria Harbour before and after the implementation of the projects up to 2012 are very similar.  The reclamation will only cause slight change in the prevailing currents in the harbour.

·                The predicted mean discharges across the Victoria Harbour East (Lei Yue Mun) and Victoria Harbour West (Yau Ma Tei - Western District) will be decreased by less than 5% and 2%, respectively, during the wet season after the completion of WDII reclamation, as well as othe rreclamations within the Victoria Harbour, including the CRIII, Kowloon Point Development, the South East Kowloon Development, the Yau Tong Bay Development and the Western Coast Road reclamation.

·                The predicted mean discharges across the Victoria Harbour East (Lei Yue Mun) and Victoria Harbour West (Yau Ma Tei - Western District) will be decreased by about 4% and less than 1.5%, respectively during the dry season after the completion of WDII reclamation, as well as other reclamations within the Victoria Harbour, including the CRIII, Kowloon Point Development, the South East Kowloon Development, the Yau Tong Bay Development and the Western Coast Road reclamation.

Therefore, it is concluded that the projects planned will have minimal impact on the hydrodynamic regime of the harbour.

The report further stated that a comparison between the baseline and operational water quality modelling results suggested that the levels of pollutant near Wan Chai and the neighbouring areas are similar under both baseline and operational scenarios.  No unacceptable impact associated with the operation of the projects upon the water quality in the Victoria Harbour is envisaged.  Based upon the modelling results, operational phase mitigation means are not considered necessary.  Operational water quality monitoring and audit is therefore not considered necessary.

10.7.8                            Mitigation

10.7.8.1            Culvert L Outfall

10.7.8.1.1                The creation of a zone of relatively slack water around culvert outfall L results in locatised elevations in E.coli. The embayment will last for some 20 months from the construction of the CRIII seawall in May 2005 until the reclamation of the adjacent area under the WDII project in January 2007.  As a mitigation measure, to avoid the accumulation of water borne pollutants within this embayment, an impermeable barrier, suspended from a floating boom on the water surface and extending down to the seabed, will be erected by the CRIII Contractor on completion of the CRIII eastern seawall. The barrier will channel the stormwater discharge flows from Culvert L to the outside of the embayment.  The CRIII Contractor will maintain this barrier until the WDII Contractor takes possession of this site, where upon the WDII Contractor will takeover the maintenance of this barrier until the reclamation works in this area are carried out and the new Culvert L extension is constructed.

10.7.8.2            Floating Debris

10.7.8.2.1                The result of the floating debris simulation showed that the proposed reclamation does not have a high potential to trap floating rubbish. However, collection of floating debris should be carried out at least once per day to the east of the CRIII site until completion of the WDII works in this area.  Debris should be collected and disposed of to landfill.

10.8                                  Thermal Discharges

10.8.1                            Introduction

10.8.1.1            A number of existing seawater cooling water pumping stations are located within the CRIII area.  Spent cooling water from these cooling water systems discharges through culverts / outfalls into the harbour at locations shown in Figure 2.2 (refer to Chapter 2).  The flows through these discharge points in the CRIII area average between 1,600 m3/day and 483,300 m3/day.  Questionnaires sent to the owners/operators of the pumping stations to request information regarding the operating conditions and criteria of the existing cooling water systems included questions related to the temperature elevation of the spent cooling water discharge when compared to the ambient temperature of the harbour.  The replies received from the Electrical and Mechanical Services Department (EMSD) relating to cooling water pumping stations servicing Government Buildings stated that the maximum temperature elevations are in the order of 5°C (refer also to Appendix S).  The replies received from private owners indicated temperature elevations of a similar order.  It should be noted, however, that field measurements taken within the CRIII area (as part of the Marine Site Investigation Contract for CRIII) adjacent to the discharge points indicated maximum temperature elevations of less than 2°C.

10.8.2                            Reprovisioning Arrangements for Cooling Water Pumping Stations

10.8.2.1            The Brief for CRIII states that the reprovisioning of the cooling water pumping stations affected by the CRIII works will be on a “like for like” basis.  The currently proposed locations of the reprovisioned cooling water pumping stations and their associated discharge outfalls are indicated on Figure 10.26.  In terms of environmental input to engineering design, cooling water intakes and outfalls for reprovisioned cooling water pumping stations have been located on the formed reclamation in locations designed to maximise geographic separation (within the imposed land use planning and engineering constraints) in order to minimise the potential for any adverse impacts from outfalls on the operation of the reprovisioned cooling water intakes.  Additionally, environmental input into the design has provided vertical separation with the reprovisioned cooling water intakes located 5 m to 6 m deeper than the reprovisioned outfall locations.  It should be noted that the MTRC and Hong Kong Academy for Performing Arts cooling water pumping stations and associated discharges located to the east of the CRIII area will not be reprovided during the CRIII works but will be reprovided during the WDII works.  Information obtained from the WDII consultant indicates these reprovisioned cooling water pumping stations would be positioned close to the northern edge of the existing HKCEC island as indicated on Figure 10.26.  The WDII Consultant has further advised that the reprovisioned cooling water pumping stations would be constructed in the early part of the WDII works to permit reclamation to the north of the existing pumping stations to proceed.

10.8.3                            Operation of Reprovisioned Cooling Water Pumping Stations

10.8.3.1            As the pumping stations reprovided as part of the CRIII works will be reprovided on a “like for like” basis, it is reasonable to conclude that the operation of the new pumping stations will not be affected by their relocation to the new waterfront.  In addition it can be concluded that the elevation of discharge outfall temperatures above the ambient temperature of the harbour will not be affected by the relocation of the pumping stations.  In any event, it should be noted that the proponent for the CRIII works has no influence over the existing operators but is simply reprovisioning their facilities to permit the reclamation to be constructed.  The existing owners are currently, and after CRIII will continue to be, regulated under the Water Pollution Control Ordinance to ensure that their discharges are of an acceptable temperature to protect the receiving water of the harbour.

10.8.4                            Future Development within CRIII Area

10.8.4.1            In recognition of the fact that the public will only condone reclamation where it would contribute to the material enhancement of the waterfront to the mutual benefit of both tourists and residents, the land uses proposed for the new CRIII reclamation are predominantly Government/Institution/Community and Open Space uses.  The need for additional cooling water is therefore expected not to be significant and limited largely to systems under the control of EMSD.  Therefore is anticipated that there will be no significant increase in thermal discharges from the CRIII area when compared to the existing situation.

10.8.5                            Assessment of Thermal Discharges

10.8.5.1            For the CRIII Minimum Reclamation Option, the cooling water pumping stations will be reprovisioned into areas of significantly greater water movement than their existing Central shoreline locations in which there is presently little water movement (refer to surface flow patterns for Baseline and Final Layouts in Appendix O).  The pumping stations will also be located proximal to the main channel water flow in Victoria Harbour which will ensure that warmer water associated with the cooling water discharge outfalls will be effectively diluted and dispersed by the relatively strong flow within the main harbour channel.

10.8.5.2            As indicated in Chapter 4 of this report, in order to maintain the operation of the existing cooling water pumping stations until the reprovisioned pumping stations are completed and commissioned, two small sections of advance reclamation need to be carried out (refer to Figure 4.1 in Chapter 4).  The size and location of these advance  sections of reclamation relative to the existing cooling water pumping station intakes / outfalls are such that the extent and pattern of temperature increases associated with the existing cooling water systems are not expected to change from the present day situation.  The advance sections of reclamation have also been designed so that they are as small as possible and have the maximum physical separation possible from existing cooling water facilitates so as to ensure that the existing facilities are not adversely affected by the reclamation works.

10.8.5.3            The assessments included above were prepared at a time when no information was available on the Wan Chai Development Phase II project.  Any further impacts of the WDII works on the thermal discharges from CRIII, if any, have been addressed as part of the EIA Study for that project (Reference 8).

10.8.6                            Summary

10.8.6.1            An assessment of the effects of the CRIII works on existing thermal discharges associated with cooling water facilities located along the Central Waterfront has concluded the following :

·                There will be no significant increase in thermal discharge produced from CRIII when compared to the existing situation (refer to paragraphs 10.8.2 and 10.8.4);

·                At the completion of CRIII, the reprovisioned and new cooling water discharge points will be located at well flushed water, significantly improving the location of the existing discharge points prior to CRIII (refer to paragraphs 10.8.2 and 10.8.5); and

·                There will be no significant change in flow across the major flow channels in the harbour (refer to paragraph 10.7.3).

10.9                                  Biocide Discharges

10.9.1                            For cooling water systems which use seawater, it is common practice to use selected chemicals also known as “biocides” to control the growth of fouling organisms particularly within the supply and discharge pipework.

10.9.2                            Questionnaires sent to the owners operators of the pumping stations requesting information regarding the operating conditions and criteria of the existing cooling water systems included questions related to chemical treatment of the seawater.  The replies received from the Electrical and Mechanical Services Department (EMSD) relating to cooling water pumping stations servicing Government Buildings stated that no chemical treatment was used at pumping stations under their control (refer also to Appendix S).  The replies received from private owners did, however, indicate that chemical treatments were used but that details of these had been submitted to EPD and accepted by them.

10.9.3                            The locations of exiting cooling water pumping station outfalls (both those under the control of EMSD and private owners) where residual biocides will be discharged to the harbour are indicated on Figure 2.2 (refer to Chapter 2).  During the course of the CRIII works, all of these outfalls with the exception of the MTRC, Hong Kong Academy for Performing Arts and Culvert L Stormwater outfalls will be extended with the reclamation to discharge at the new waterfront.  The location of the outfalls at the completion of CRIII are indicated on Figure 10.26.

10.9.4                            The Brief for CRIII states that the reprovisioning of the cooling water pumping stations affected by CRIII works will be on a “like for like” basis.  This being the case, it is reasonable to conclude that the operation of the new pumping stations will not be affected by their relocation to the new waterfront.  In addition, it can be concluded that the systems used by existing owners, where applicable, to control the growth of fouling organisms will not be affected by the relocation of the pumping stations.

10.9.5                            Whilst it has been concluded in paragraph 10.9.4 that the existing owners will continue to utilise the same chemical treatments on completion of CRIII, as applicable, which they utilise at present, it should also be noted that the proponent for the CRIII works has no influence over the existing operators but is simply reprovisioning their facilities to permit the reclamation to be constructed.  The existing owners are currently, and after CRIII will continue to be, regulated under the Water Pollution Control Ordinance to ensure that their discharges are of acceptable quality to protect the receiving water of the harbour.

10.9.6                            In recognition of the fact that the public will only condone reclamation where it would contribute to the material enhancement of the waterfront to the mutual benefit of both tourists and residents, the land uses proposed for the new CRIII reclamation are predominantly Government/Institution/Community and Open Space uses.  The need for additional cooling water is therefore expected not to be significant and limited largely to systems under the control of EMSD.  As noted in paragraph 10.9.2, existing cooling water facilities controlled by EMSD do not used chemical treatment and therefore it is reasonable to conclude that this would also apply to future systems under their control.  Therefore, it is anticipated that there will be no significant additional residual biocide loads entering the harbour as a result of the CRIII project.

10.9.7                            The reprovisioned cooling water pumping stations will be located into areas of significantly greater water movement than their existing Central shoreline locations in which there is presently little water movement.  They will also be relocated proximal to the main channel water flow in Victoria Harbour which will ensure that residual biocide discharges will be effectively diluted and dispersed by the relatively strong flow within the main harbour channel.

10.9.8                            Information provided by existing owners (refer to paragraph 10.9.2) indicates that individual discharges contain very low levels of residual biocides in order to satisfy EPD requirements.  These low concentrations in association with the improved discharge locations at the completion of CRIII as described in paragraph 10.9.7 mean that concerns over increased biocide levels would relate more to an overall cumulative effect rather than specific local inshore plumes directly related to the CRIII area.

10.9.9                            An assessment of the effects of the CRIII works on residual bicoide discharges associated with cooling water facilities located along the Central Waterfront has concluded the following :

·                Information obtained indicates that the existing users will continue to operate their systems as at present (refer to paragraphs 10.9.2 and 10.9.4);

·                The CRIII project proponent has no influence over existing pumping station owners who in any case are regulated under the WPCO to ensure that their discharges are of acceptable quality to protect the receiving marine water (refer to paragraphs 10.9.2 and 10.9.5);

·                There will be no significant increase in the use of cooling water for the new reclamation and therefore no significant additional residual bicoide loads entering Victoria Harbour (refer to paragraph 10.9.6); and

·                The residual biocides upon completion of CRIII will discharge into well mixed waters of Victoria Harbour where they will be effectively diluted and dispersed by the strong flow within the main harbour channel (refer to paragraphs 10.9.7 and 10.9.8).

The assessments included above were prepared at a time when no information was available on the Wan Chai Development Phase II project.  Any further impacts of the WDII works on the biocide discharges from CRIII, if any, have been addressed as part of the EIA Study for that project (Reference 8).

10.10                              Conclusions

10.10.1                        Construction Phase

10.10.1.1        Results of the sediment quality analysis in the study area indicate that the marine sediment which may be disturbed during construction contain about 2% heavy metal moderately contaminated and about 63% seriously contaminated marine mud.

10.10.1.2        A review of the reclamation method for the CRIII Minimum Option recommended that all mud be dredged.  The Secretary of the Marine Fill Committee has confirmed that he has no objection to the proposal to remove 580,000m3 (i.e. total removal) of soft seabed deposits from below the CRIII site.  For plume modelling of SS, two scenarios of dredging and filling activities at different times of the construction schedule have been simulated to assess the impact of suspended solids and dissolved oxygen. The results indicated significant increase in SS at the construction site and near areas of dredging and filling. Mitigation measures including the use of closed clamshell grab-dredging and prohibition of stockpiling of dredged material on site are recommended. The use of silt screens at cooling/flushing water intakes would also assist in ensuring that no disruption occurs as a result of CRIII works.

10.10.1.3        Marine disposal of dredged mud should follow the procedures of Works Branch Technical Circular Nos. 3/2000 and 12/2000 as applicable for dumping permit application. The Sediment Quality Study Final Report prepared in 1996 showed that the surface layer of the marine sediment is essentially Class C contaminated mud.  Further sediment quality studies are in progress to re-confirm the sediment classification in accordance with the recently issued WBTC 3/2000.  It is, however, required that the MFC will need to finalise the disposal allocation and contingent conditions. The permit holder should take the responsibility to ensure that the permit conditions fully satisfy the Director of Environmental Protection.  Mitigation measures properly implemented will minimise the environmental impact during transportation and marine disposal of dredged material to acceptable levels.

10.10.1.4        For the simulation of water quality impact during construction, the intermediate layout of the proposed reclamation was simulated under wet season tide conditions.  The wet season was selected for modelling for the Intermediate Layout after review of the Baseline and Final Layout results.

10.10.1.5        The model results indicated that for all the water quality parameters simulated, there was no obvious deterioration in water quality in any local area of the proposed reclamation.  It is therefore concluded that the intermediate layout of the proposed reclamation would not result in any significant deterioration in water quality compared to present day conditions. Model results also predicted that current expedient connections would not generate water quality problems in relation to the proposed reclamation.

10.10.1.6        No information was available for the Wan Chai Development Phase II (WDII) project at the time modelling works were conducted for this study.  An assessment of the combined CRIII and WDII reclamation as undertaken during the WDII EIA Study is, however, included in Appendix Q.  It should be noted, however, that according to the latest programme information available for the WDII Study, at the time of writing this report, that in mid 2004 works would only have commenced in the Causeway Bay and Wan Chai areas (to the east of the Hong Kong Convention and Exhibition Centre) and should not affect the assessments presented for the CRIII Intermediate Layout.

10.10.1.7        The simulations of floating debris show that the intermediate layout of the proposed reclamation has potential to trap floating rubbish. To avoid accumulation of floating debris, appropriate collection and removal facilities will need to be deployed to the site. Collection should be carried out on an as needed basis. Monitoring and control of the construction activities should also be undertaken to control the release of construction waste and rubbish from the construction site.

10.10.1.8        Based on the assessment of the water quality impact, an environmental monitoring and audit (EM&A) programme is considered necessary to obtain a robust, defensible database of baseline information of water quality before the construction, and thereafter, monitor any variation of water quality from the baseline conditions during the construction.

10.10.2                        Operation Phase

10.10.2.1        For the simulation of the proposed reclamation layout, it was assumed that the Stonecutters Island outfall would be commissioned and that no sewage discharges would originate from Kowloon within the modelled area.

10.10.2.2        After the reclamation is completed, surface flow paterns at the boundary of the reclamation, except in the water body between the CRIII and HKCEC Extension reclamation, will return to those close to the original coastline prior to reclamation.  This water body is, however, likely to be a temporary feature and will be removed during the planned Wan Chai Development Phase II project.

10.10.2.3        The modelling indicates that the completed reclamation will not result in any adverse impact on the large scale water quality in the modelled area.

10.10.2.4        The simulation of floating debris showed that the proposed reclamation would not have a high potential to trap floating debris.  To avoid accumulation of any floating debris, however, appropriate collection and removal at least one per day should be employed unit the removal of this area as part of the WDII works.

10.10.2.5        Mitigation measures are recommended to control the accumulation of the floating debris at the potential “slack corners” of the CRIII reclamation.  The EM&A programme will include site inspection to monitor the efficiency of these mitigation measures.

10.10.2.6        No information was available for the Wan Chai Development Phase II Project at the time modelling works were conducted for this study.  A cumulative assessment of the combined CRIII and WDII reclamation and other planned reclamations in Victoria Harbour up to 2012 is, however, included in the EIA Study Report for the WDII Project.  For the readers reference and information, this cumulative assessment from the WDII EIA report is included in Appendix Q of this report.

 

 


11.                                      ECOLOGY

11.1                                  General

11.1.1                            The study area has no Sites of Special Scientific Interest (SSSIs), Country Parks, Fish Culture Zones, Marine Parks or Reserves, or other areas of recognised ecological or conservation interest. Water quality in Victoria Harbour is considered poor due to high organic loads, and is characterised by low levels of dissolved oxygen (particularly deeper in the water column) and high suspended solids and turbidity. As a result, much of the Harbour is ecologically degraded, and will only support pollution tolerant benthic species and fouling organisms.  This was confirmed in the EPD Water Quality Report for Hong Kong (1994).

11.2                                  Habitat

11.2.1                            The existing marine environment is composed of two habitat types:

·                natural seabed (mud, silts, shell fragments and stone); and

·                the man-made coastline consisting of concrete/stone block seawall and reclamation walls, with some wooden piles.

11.2.2                            Water quality within Victoria Harbour is low, and the quality of seafloor sediment reflects a high organic environment, with heavy metal contamination and anaerobic conditions.

11.2.3                            Terrestrial habitat is primarily urban or reclamation fill. There are no existing areas of terrestrial ecology that are considered important in the immediate vicinity of CRIII.

11.3                                  Ecological Baseline

11.3.1                            Soft Bottom Benthos

11.3.1.1            Few recent studies of soft bottom benthic resources have been undertaken in Victoria Harbour.  Benthic sampling undertaken in 1976 and 1979 indicated that pollution had only a limited influence on the benthos of Victoria Harbour, due predominantly to the existence of high flushing rates.  The influence of pollution on the benthic assemblage is anticipated to have increased since these surveys were undertaken.  It is envisaged that if not azoic (without life), then the soft-bottom benthic community in central Victoria Harbour would be expected to consist of a small number of pollution-tolerant species such as some polychaetes, eg Capitella capitata and oligochaetes.

11.3.1.2            More recent field sampling has been conducted as part of the EPD Study, SSDS Stage I Baseline Monitoring and Performance Verification.  A sampling station for this monitoring work was located within Victoria Harbour on the Sheung Wan side of Central Reclamation Phase 1.  Grab samples collected during a 12 months period (July 1996 – May 1997) were composed mainly of polychaetes (47% of all individuals, main species were Cirratulus filiformis, Minuspio cirrifera and Ophiodromus angustifroms), molluscs (36% - Tapes philippinarum) and crustacean (15% mainly composed of amhipods).  The occurrence of the Philippine clam (Tapes philippinarum) in the grab samples is of interest at this commercially important bivalve is more commonly associated with intertidal mud flats and not subtidal sediments.  The average number of individuals collected per grab was 27.75 which is low compared to values recorded from other studies in Hong Kong. 

11.3.1.3            Samples collected as part of CEDs Seabed Ecology Studies showed much variation between sites with the average number of individuals per grab (recalculated to be comparable to the SSDS data) ranging from 11.4 – 149.  The value for the harbour obtained for the SSDS was similar to values at capped pits at East Sha Chau but much lower than values obtained in old borrow areas such as Tathong Channel and Sokos.

11.3.1.4            Other field work conducted within Victoria Harbour as part of the Kowloon Point Development involved using REMOTS (Remote Ecological Monitoring Of The Seafloor) technology to examine the sediment profile for signs of infaunal activity (feeding void, burrows etc) and geophysical characteristics.  The REMOTS investigation revealed that sediments in the harbour are dominated by fine grained particle sizes and are largely anoxic due to high organic pollution inputs.  Despite the apparently poor conditions, the presence of poloychaete tubes and feeding voids in some images indicated the presence of some infauna.

11.3.2                            Field Survey of Soft Bottom Benthic Organisms

11.3.2.1            Due to the lack of site-specific information and the recent deterioration in harbour conditions, it was decided that a limited field survey was necessary to verify the results of the literature review.  The survey was conducted in 1996.

11.3.2.2            Three sampling locations were selected within the proposed reclamation area.  Geotechnical samples were extracted at these locations using a vibrocore.  The upper 30 cm was removed for ecological analysis for benthic invertebrates.  The samples were sieved through a 500 mm mesh to remove the sediment, and any remaining material stored in 70% ethanol to be later sorted and identified.  Samples were examined under a dissecting microscope to identify species present.

11.3.3                            Results of Field Survey

11.3.3.1            The sediment samples were malodorous, anoxic and highly sulphurous with the top layer being almost fluid, possibly due to a combination of the sediment characteristics and the extraction method.  No live benthic invertebrates (>500 mm) were collected at any of the stations.  The sediment at the first sampling location was highly malodorous and was composed exclusively of silt.  Sediment at the second sampling location consisted of a large number of empty bivalve and gastropod shells, shell fragments, clay and silt.  At the third sampling location, there were few shell fragments with predominantly silt and clay sediment.  It is possible that some small invertebrates (e.g. small oligochaetes) passed through the 500 mm mesh, however, it is was decided that given logistical and health and safety constraints this was the most efficient method that could be employed in these specific circumstances.

11.3.3.2            Although the sampling was limited, the results of this field survey indicate that the soft bottom marine environment in the proposed reclamation area is polluted and lacks a macroinvertebrate community.

11.3.4                            Hard Surface Organisms

11.3.4.1            Various species of algae, coelenterates, ascidians, polyzoans, sponges, crustaca, molluscs and polychaetes (listed in Table 11.1) are observed on wharf piles embankments, grognes and other marine structures throughout Hong Kong as detailed in Morton and Morton (1983).

11.3.4.2            Other studies of particular fouling organisms have indicated, however, that the species assemblage of a location may be determined by their tolerance to the physical conditions at that site.  For example, Huang et al (199) examined the bryozoan fouling community in Hong Kong and identified 37 species, of which 5 occurred in more that 15% of the samples and were gravimetrically dominant (Table 11.1).  A total of 7 species were found on fixed concrete piles in Central.  There were distinct preferences for 3 defined hydrographic zones; the estuarine western waters, the central transition zone (in which the Study Area is located), and the oceanic eastern waters.  Liu et al (1990) carried out a similar study on cirripede foulers (barnacles) and found 23 species in total of which 11 were restricted to the central, transitional water (Table 11.1).  Wang and Huang (1993) report that 70 species of fouling polychaetes were recorded from the Territory, of which 3 species were dominant namely Serpula vermicularis, Hydroides elegans and Pomatoleios kraussii.  Fifteen species, including 2 of the 3 dominant species, occurred on a pier in Central and distributions with physical factors such as salinity and tidal action were observed.  The dominant specials occurring at Central were Hydroides elegans and Pomatoleios kraussii.

11.3.4.3            Some other species which are more typically found on a rocky shore may also occur on the seawall, including limpets, chitons, other gastropods and crabs.


 

Table 11.1 : Organisms Potentially Present within the Study Area

 

Species

Algae

Ulva congoblata

 

Enteromorpha prolifera

 

Rhizoclonium riparium

 

Codium cyclindricum

 

Colpomenia sinuosa

Hydrozoa

Haliplanella luciae

Ascidiacae

Botrylloides persipicuum

 

Botryllus schlosseri

 

Ascidia sydneiensis

 

Ciona intestinalis

 

Styela plicata

 

S. canopus

 

Herdmania momus

Bryozoan

Bugula neritina

 

Schizoporella unicornis

 

Sinupetraliella umbonatoidea

 

Membranipora amoyensis

 

Conopeum reticulum

Barnacle

Balanus reticulatus

 

B. trigonus

 

B. amphitrite amphitrite

 

B. cirratus

 

B. albicostatus

 

Ilba cumingi

 

Capitulum mitella

 

Euraphia withersi

 

Chinochthalamus scutelliformis

 

Tetraclita squamosa

 

Chirona amaryllis

Mollusc

Perna viridis

 

Septifer bilocularus

 

Saccostrea cucullata

 

Martesia striata

 

Teredo furcifura

 

T. navalis

Annelida

Cirriformia capensis

 

Eulalia viridis

 

Halosdyna brevisetosa

 

Nereis multignatha

 

Perinereis cultrifera

 

Marphysa sanguinea

 

Palola siciliensis

 

Lumbrinereis sp.

 

Dorvillea cf pseudorubrovittata

 

Pherusa parmata

 

Demonax japonicus

 

Potamilla torelli

 

Loimia medusa

 

Serpula vermicularis

 

Hydroides dirampha

 

H. elegans

* for sources of information refer to Section 11.3.4.

11.3.5                            Others

11.3.5.1            Harbour waters provide habitat for some species of fish, although little is known of their species composition and ecology.  A study of inshore fish at the north coast of Lantau revealed an assemblage dominated by the small, non-resident Ambassis gymnocephalus and the resident Leiognathus brevirostrus.  Details of the study were published in “Inshore Fish Community Structure in a Subtropical Estuary” by Richards J and B.S.S Wu (1985). The same assemblage is unlikely to occur in Victoria Harbour, given the poor water quality, lack of natural coastline and disturbances from marine traffic.

11.3.5.2            At least one dozen marine mammal species occur in Hong Kong waters, however, only the Chinese White Dolphin (Sousa chinensis) in western waters and the finless porpoise (neophocaena phocenoides) in the east are considered to be permanent residents.  Over the last 5 years research has been conducted on Sousa chinensis but information regarding other cetaceans is sparse.  No sightings of Sousa chinensis have been reported east of Green Island and, therefore, the CRIII cannot be regarded as of importance to this dolphin.

11.3.5.3            The local biology of the finless porpoise is less well known and is currently the subject of an ongoing study for AFCD.  Sightings of the porpoise have been made across the breadth of the southern waters south of the SAR and well into Mirs Bay to the east.  No sightings have been recorded either in Victoria Harbour or N Lantau and the study area is thus unlikely to be of any significance for porpoise.

11.3.5.4            Some migratory and resident birds are recorded as using Victoria Harbour (Vinney and Phillips, 1989).  The ubiquitous Black-eared Kite (Milvus lineatus) is Hong Kong’s most common raptor and is often seen scavenging in Victoria Harbour.  The Black-headed Gull (Larus ridibundus), Herring Gull (Larus argentatus) and Little Egret (Egretta garzetta) often make an appearance in the harbour and there have been several records of Red-necked Phalarope (Phalaropus lobatus) during spring migration.  Increased reclamation and harbour traffic may deter these species from using it as a migration stopover now and in the future.  During the ecological survey, undertaken as described in Section 11.3.2, several (<10) Black-headed Gulls were observed perching on a buoy and scavenging for food within the CRIII area.  Other than this there is no evidence that the CRIII area is of particular significance for these species.

11.3.6                            Commercial Fisheries

11.3.6.1            The two fishing areas, O152 (Central) and O153 (Wanchai) overlapping the CRIII area are mostly used by purse seine, cage trap and gill net operators.  The vessels operate exclusively out of Yau Ma Tei home port (0032), which is home for 29 commercial fishing vessels including 18 mixed operation vessels, 8 shrimp trawlers, 2 P4 and 1 purse seine.  These vessels operate approximately 10% of their time in the areas 0152 and 0153 and their catches are mainly composed of rabbitfish (Siganus canaliculatus) and species of scad (Caranx sp).

11.4                                  Ecological Importance

11.4.1                            Based on the field surveys and discussion presented in Section 11.3 above, the current ecological assessment shows that the marine ecological resources present within the CRIII area are considered of low ecological value.  This has been determined on the basis of the following considerations, in accordance with the EIAO-TM Annex 8 Table 2 criteria :

·                Naturalness : Intertidal habitats are man-made areas and subtidal habitats have been subject to extensive disturbance through high pollution loads.

·                Size : (not applicable as only meaningful if the habitats are of some value)

·                Diversity : The faunal diversity in the intertidal habitats is reported as very low.  Diversity in the subtidal habitats was extremely low.

·                Rarity : No rare species found.

·                Fragmentation : The man-made shore is surrounded by shores of a similar nature.

·                Ecological Linkage : The present habitats are not functionally linked to any highly valued habitat in close proximity.

·                Potential Value : Low potential as significant management efforts or long natural processes would be required for the site to become an area with conservation interest.

·                Nursery / breeding Ground : No records of significant nursery / breeding ground within the CRIII Study Area.

·                Age : Young artificial habitats.

·                Abundance / Richness of Wildlife : Both the intertidal and subtidal shores possibly support few species in very low abundances.

11.5                                  Impact Assessment

11.5.1                            Construction Phase Impacts

11.5.1.1            Direct Impacts : As a result of reclamation activities an area of the natural seabed (18 hectares) will be lost.  The subtidal part of the seawalls constructed after the reclamation has been completed will offer potential surfaces for colonisation by benthic organisms.

11.5.1.2            Indirect Impacts : During the construction phase, the subtidal assemblage of the unreclaimed CRIII area could potentially be affected as a result of changes in water quality.  Suspended sediment generated during the dredging and filling stage will cause an increase in turbidity in the water column and higher rates of deposition on the seafloor.  Such elevated suspended sediment concentrations may cause smothering of filter feeders such as bivalves and clogging of gill filaments in fish and other organisms.  Another potential indirect impact involves reduction in dissolved oxygen concentration caused by elevated concentrations of suspended sediments.  An increase in solids in the water column will result in the following effects on dissolved oxygen :

·                Reduced sunlight penetration, lowered rate of photosynthesis of phytoplankton (primary productivity) and thus lower rate of oxygen production in the water column.

11.5.2                            Operational Phase Impacts

11.5.2.1            Impacts during the operational phase of the reclamation are most likely to occur through changes to the tidal flow and hydrographic regime of the harbour.  Increases or decreases in movement of water through the harbour could potentially affect subtidal assemblages through increased scouring of sediments (a result of flow increase) or increased sedimentation / depletion of DO as a result of flow decreases.  Impacts to water quality discussed in Chapter 10 have discussed this issue and concluded that flows will return to levels similar to the original coastline prior to reclamation.  The CRIII coastline brings the benefit of reducing the areas in the harbour that currently experience reduced flows and consequent depletions in DO.

Urban development within the Central area resulting from recent reclamations has reduced the number of natural shore-line perching site for birds.  The natural habitat for birds are also being continually disturbed by marine traffic.  The reclamation area is therefore not considered an important habitat for birds.

Existing cooling water pumping stations will be reprovisioned to the new waterfront as a result of the CRIII works.  The impacts of the relocation of these facilities including the impacts of biocide usage for keeping cooling water systems clear of fouling organisations is discussed in Chapter 10.  The discussion in Chapter 10 indicates that it is expected that there would be minimal, if any, ecological impact arising from these discharges for the relocated cooling water pumping stations.

11.6                                  Impact Evaluation

11.6.1                            Based upon the discussion in Sections 11.3 – 11.5 above , the ecological impact associated with the construction phase (both direct and indirect impacts) and operational phase of CRIII is considered low as evaluated in accordance with Annex 8 of the EIAO – TM in the following section.

·                Habitat Quality : Low quality artificial habitats.

·                Species : No species of conservation interest present.

·                Size / Abundance : The reclamation area is 18 hectares but the seabed to be reclaimed has very low ecological value and the poor intertidal assemblages are likely to recolonise the seawalls post reclamation.

·                Duration : CR3 reclaimed area will be long term.

·                Reversibility : Impacts to the seabed are permanent and irreversible, impacts to the intertidal shore are reversible.

·                Magnitude : Developed into terrestrial and more urban environment.

11.7                                  Mitigation

11.7.1                            It is anticipated that no specific mitigation measures will be needed to preserve ecological resources in the study area.  It should be noted, however, that measures for mitigating water quality impacts will also serve to minimise the impacts on marine ecology especially for areas outside the reclamation area.

11.8                                  Conclusion

11.8.1                            No unacceptable ecological impact is anticipated. The proposed seafront promenade and landscaped deck to the west of the site will be landscaped and vegetated, thus providing an improved terrestrial environment compared to the existing seaboard. The new seawall structure will again provide habitats for fouling (epifaunal) organisms to colonise.

 


12.                                      LAND CONTAMINATION

12.1                                  General

12.1.1                            Since CRIII involves land reclamation, there is no historical or existing land which is considered to be contaminated land according to the potentially contaminating land uses listed in Annex 19, Section 3 of the EIAO TM. Only the dredged contaminated marine mud will require special consideration. There are, therefore, no contaminated land issues associated with the formation of CRIII.

 

 

 

 


13.                                      WASTE DISPOSAL AND BIOGAS ASSESSMENT

13.1                                  Introduction

13.1.1                            At the commencement of the detailed design for the CRIII Minimum Option, a review of reclamation methods was conducted.  The key findings of this review are presented in Appendix B.  The review recommended that a fully dredged reclamation method should be adopted for the CRIII project. A Discussion Paper, prepared as part of the review, providing the rational for mud removal was submitted to the Secretary of the Marine Fill Committee.  In response to this submission the Security of the Marine Fill Committee confirmed that he had no objection to the proposal to remove 580,000m3 (i.e. total removal) of soft seabed deposits from below the site.

13.1.2                            Based upon currently available site investigation information, it is estimated that  approximately 375,000 m3 of the material to be dredged will be seriously contaminated. Demolition of the existing piers and associated buildings will contribute to waste arisings. In view of the relatively small scale of the land-based construction works, other construction waste arisings are expected to be minimal.

13.2                                  Existing Conditions

13.2.1.1            The evaluation criteria for classifying the level of contamination of marine sediments by their heavy metal content and the relevant Technical Circular were discussed in Chapter 3.  New procedures have recently been introduced for sampling and testing for projects commencing after have 31 December 2001.  The current construction programme for CRIII indicates works will start in August 2002, hence the new procedures will apply. For the purposes of this study the assessment, however, is based upon the previous evaluation criteria as additional sediment quality assessment works to comply with the new procedures are still in progress at the time of writing this report.

13.2.1.2            The results of EPD routine sediment sampling indicate that the marine sediments within the centre of Victoria Harbour are Category H in accordance with WBTC 3/2000.  As shown in Table 13.1, the concentrations of copper, nickel, and lead measured in sediment samples between 1993 to 1997 at the sampling station near the study area (VS5) contribute to the clarification.  At the sediment sampling location to the west of the study area (VS6), the concentrations measured of chromium, copper, mercury, lead and zinc contribute to the Category H clarification.

 

 

 

 

 

 

 

 

 

Table 13.1 :  Heavy Metal Parameters at EPD Stations VS5 and VS6 in Central Victoria Harbour(mg/kg weight)

Station

Cd

Cr

Cu

Hg

Ni

Pb

Zn

Sediment* Classification

VS5

0.1-0.5

13-42

159-170

0.1-0.4

6-46

19-87

45-120

H

VS6

0.2-1.0

36-92

130-360

0.3-1.6

16-35

50-130

130-240

H

*      Classification according to "Works Bureau Technical Circular No. 3/2000 - Management of Dredged / Excavated Sediment"

13.2.2                            A sediment sampling exercise was conducted for the CRIII Full Reclamation area (refer to Figure 1.1 in Chapter 1) to more accurately determine the contamination levels of sediments that would be removed during the reclamation. The findings of the study were detailed in Central Reclamation, Phase III - Studies, Site investigation, Design and Construction - Sediment Quality Study Final Report (Atkins Haswell, 30 April 1996). The findings of the study have formed the basis of the assessment of sediment quality for the CRIII Minimum Option, although they will be reviewed in accordance with the new sediment quality assessment procedures when ongoing sediment quality study works are completed.  The heavy metal analysis results from the previous Sediment Quality Study showed serious contamination of sediments to depths of up to 3 metres, but more typically in approximately the first 1 metre below the sea-bed. Particularly high levels of copper, zinc and chromium were encountered. The results also showed strongly anaerobic conditions within the sediments and high total organic carbon content (up to 6% of dry weight) which has a high oxygen demand.  As part of the previous Sediment Quality Study elutriate tests were also conducted to examine what micro-pollutants would be released when the marine mud was disturbed. These tests showed that impacts would be within acceptable criteria.  Pore water analysis tests also conducted as part of the Sediment Quality Study showed relatively lower concentrations of heavy metals compared to the marine mud analysis. The total organic carbon content, however, was very high, ranging from 90 to 1,850mg/L.

13.3                                  Future Conditions

13.3.1                            Once the connections from Hong Kong Island to the Stonecutters Sewage Treatment Works are completed, it is anticipated that the discharge of high organic loading into the Harbour will be reduced. As a result, it is anticipated that any further deterioration in sediment quality will be prevented.

13.4                                  Potential Sources of Impact

13.4.1                            The construction activities will result in the generation of a variety of wastes which can be divided into distinct categories based on their nature and ultimate method of disposal.  The types of waste include:

·                marine sediments;

·                demolition waste;

·                construction waste;

·                excavated and inert material suitable for reclamation and fill;

·                chemical waste; and

·                general refuse.

13.5                                  Marine Sediments

13.5.1                            The basic requirements and procedures for dredged mud disposal are specified under the recently issued WBTC 3/2000.  The management of the dredging, use and disposal of marine mud is monitored by the Marine Fill Committee (MFC), while the licensing of marine dumping is the responsibility of the Director of Environmental Protection (DEP).

13.5.2                            Under the terms  of WBTC 3/2000, the rational for the removal of any volume of contaminated marine sediment must be directed to the Secretary of the Marine Fill Committee, former title Principal Government Geotechnical Engineer (PGGE) who acts as advisor to the MFC on this matter.  The rational for full removal of marine sediment from below the CRIII Minimum Option site was submitted to the Secretary of the MFC in late 2000.  The Secretary of the MFC has reviewed the submissions and advised that he has no objection to the removal of 580,000m3 of marine muds from below the CRIII site (i.e. total removal of soft marine muds).

13.5.3                            The dredged marine sediments removed from the CRIII site will be loaded onto barges and transported to designated sites depending on their level of contamination.  As discussed in Section 10.5 of this report, a Sediment Quality Study for the proposed site was conducted in 1996.  This study assessed the contamination level of the sediments in accordance with EPD Technical Circular No. 1-1-92 and concluded that generally the surface layer of the sediments (from seabed to approximately 1m, but at some locations as deep as 3m) was seriously contaminated (Class C).  The contamination level of the marine sediment reduces form 2m below the seabed and generally reaches uncontaminated (Class A) levels at 3m below seabed.  Full details of the Sediment Quality Study test results are provided in Appendix P.  As the CRIII dredging works will commence after the start of 2002, marine sediment disposal requirements will be determined by the recently issued WBTC 3/2000.  Whilst a new Sediment Quality Study is in progress, for the purposes of this EIA Study, the information contained in Appendix P has been used to assess the contamination levels and hence disposal requirements in accordance with WBTC 3/2000.  This assessment has revealed that the marine sediment below the CRIII site would either be Class L or Class H.  The Class H material has contamination levels which do not exceed ten times the Lower Chemical Exceedence Limit (LCEL).  In accordance with WBTC 3/2000, this contaminated material must be dredged and transported with great care, and the mitigation measures recommended in paragraph 10.6.4 of this EIA Report should be strictly followed.  Furthermore this contaminated sediment must be effectively isolated from the environment upon final  disposal and shall be disposed off at East Sha Chau Contaminated Mud Pits, that is designated for the disposal of contaminated mud in Hong Kong.

13.5.4                            It will be the responsibility of the Contractor to satisfy the appropriate authorities that the contamination levels of the marine sediment to be dredged have been analysed and recorded.  According to the WBTC No. 3/2000, this will involve the submission of a formal Sediment Quality Report to the DEP by the project proponent, at least 3 months prior to the dredging contract being tendered.

13.6                                  Construction and Demolition Waste

13.6.1                            Construction and Demolition (C&D) material will comprise unwanted materials generated during construction activities and may include:

·                Wood from formwork and falsework;

·                Material packaging and equipment wrappings;

·                Unusable / surplus concrete / grouting mixes;

·                Damaged or contaminated surplus construction materials; and

·                Excavated materials.

13.6.2                            C&D waste will be generated from the demoilition and removal of the Star Ferry and Queen's Piers and other existing minor waterfront features.  Based upon the Construction Programme included in Appendix C of this EIA Report, the C&D waste of the existing ferry piers would take place in August 2004.  The estimated volume of C&D waste from the removal of the Star Ferry and Queen's Piers is approximately 12,000m3.

13.6.3                            The amount of C&D material expected to be generated will be quantified in the site Waste Management Plan to be prepared by the Contractor.  Since the construction activities will be located near the waterfront, improper management of C&D materials or spillage of slurry / grouting mixes may introduce debris and pollutants to the harbour waters, and mitigation measures will be required (refer to paragraph 13.11).

13.6.4                            Construction and Demolition material generated from the demolition works will be sorted on-site into public fill (which should be re-used on-site as far as possible) and C&D waste for disposal at landfill sites).  All suitable  C&D material will be re-used as public fill material in the CRIII reclamation (for filling from +2.5mPD up to formation level), provided that the material is of a suitable size and grading.  By reducing the quantity of C&D material requiring off-site disposal, the potential for environmental impacts from the transportation of material by road will be reduced.  It is , however, recommended that C&D material should be transported from the site by barge to reduce impacts from road transportation. 

13.6.5                            Excavated materials will mainly arise from the excavation works for the Central-Wan Chai Bypass and Hong Kong Station Extended Overrun Tunnel tunnels.  This material will be generated through bulk execution after completion of the tunnel permanent and/or temporary walls.  The excavated material will comprise mainly of reclamation fill material placed during the CRIII project or the earlier CRII project.  These materials will be re-used on-site as fill material for other areas, except for material excavated from the final stages of the tunnel excavation that would require off-site disposal.  Considering the inert nature of the fill material, re-use on site will not result in any unacceptable environmental impact.

13.6.6                            The excavated material from the excavation for the tunnel construction (both the Central-Wan Chai Bypass and Hong Kong Station EOT) and to a lesser extent for box culverts on the reclaimed land will either be marine sand or surplus soft fill from other land formation projects.  The quantity of surplus excavated material (largely from the void casted by the tunnels) is estimated to be approximately 439,000m3 for the Central Wan Chai Bypass and 177,000m3 for the Hong Kong Station EOT.  As a section of the Hong Kong Station Extended Overrun Tunnel will be located in part on existing land formed under the CRII project, approximately  67,000m3   of existing fill material will also be excavated.  The estimated volume of surplus excavated material likely to require off-site disposal, from the final stages of tunnel excavation and diaphragm wall / barette foundations, is approximately 50,000m3 (based upon the current construction sequencing it is expected that most, if not all of this material, would be marine sand fill).  The reminder of the excavated material will be re-used in the reclamation platform.  It should be noted, however, that it is planned that the WDII project will still be in progress at the time this material will need to be disposed off-site.  As such it is possible that the surplus material identified as needing off-site disposal could be used as fill material in that project.

13.6.7                            Based upon available information for the C&D material, excluding excavated material, arising from the CRIII works, it is estimated that:

·                The quantity of C&D material generated will be : 12,000m3

·                The quantity of C&D material that can be re-used on site as public fill will be : 8,000m3;

·                The quantity of C&D material to be re-used in public filling areas off-site will be : None; and

·                The quantity of C&D material to be disposed of at landfills (putrescible materials e.g. wood) will be : 4,000m3.

The estimated quantities of C&D materials, in the form of excavated materials, that will be generated, re-used on site or in WDII or in public filling areas are provided in paragraph 13.6.6 above.

13.7                                  Chemical Waste

13.7.1                            Chemical waste as defined under the Waste Disposal (Chemical Waste) (General) Regulation includes any substance being scrap material, or unwanted substances specified under Schedule 1 of the Waste Disposal Ordinance (Cap. 354).  A complete list of such substances is provided under the Ordinance, however substances likely to be generated by construction  activities will for the most part arise from the maintenance of equipment.  These may include, but need not be limited to, routine replacement of oil during equipment maintenance, and equipment cleaning activities producing spent solvents/solutions which may be halogenated.

13.7.2                            Chemical wastes arising during the construction phase may pose serious environmental, health and safety hazards if not stored and disposed of in an appropriate manner as outlined in the Chemical Waste Regulations.  These hazards include:

·                toxic effects to workers;

·                adverse impacts on water quality from spills and associated adverse impacts on water sensitive receivers; and

·                fire hazards.

13.7.3                            Chemical waste will arise principally as a result of maintenance activities. It is not possible to quantify the amount of chemical waste which will arise from the construction activities since it will be highly dependent on the Contractor's on-site maintenance requirements and the amount of plant utilised.

13.7.4                            The Chemical Waste Treatment Centre (CWTC) located at Tsing Yi was commissioned in June 1993 and is the point of disposal for chemical wastes in the Territory. Disposal of chemical wastes at the CWTC will ensure that environmental, health and safety risks are reduced to a minimum, provided that correct storage procedures are instigated on the site and marine vessels.

13.7.5                            The Contractor will be required to register with the EPD as a Chemical Waste Producer and must follow the guidelines stated in the Code of Practice on the Packaging, Handling and Storage of Chemical Wastes. The Contractor must also use a licensed collector to transport and dispose of the chemical wastes generated.

13.8                                  General Refuse

13.8.1                            General refuse may include food wastes and packaging, waste paper, etc. and has the potential to cause impacts on water quality. Release of general refuse into marine waters must not be permitted as introduction of these wastes is likely to have detrimental effects on water sensitive receivers in the area.

13.8.2                            The amount of general refuse which is likely to arise cannot be quantified at this time as it will be largely dependent on the size of the workforce employed by the Contractor and the implementation of practices on-site and on board the works vessels.

13.8.3                            General refuse generated should be stored and collected separately from other construction and chemical wastes.  The Contractor will be responsible for the removal of waste generated and may commission a private waste contractor to remove any general refuse.  It is important that defined waste management practices be employed to ensure that refuse arising during the construction works do not enter surrounding waters, in order to minimise adverse impacts on marine water quality.

13.9                                  Mitigation Measures

13.9.1                            The potential environmental impacts associated with waste arisings from the construction of the proposed CRIII and the recommended handling, transportation and disposal options have been detailed in the previous sections. The next sections outline appropriate mitigation measures to minimise any impact from these construction waste arisings.  It should also be noted that under Works Branch Technical Circular, WBTC No. 29/2000, a waste management plan is required by the contractor.

13.10                              Dredging Activities

13.10.1                        The water quality assessment concluded that the proposed reclamation will involve the dredging of some seriously contaminated marine sediment. It is therefore important that appropriate measures are undertaken to ensure that impacts can be kept to a minimum.  The recommended mitigation measures should be strictly followed to minimise any potential adverse impacts of the dredging works and to protect short term, local water quality.

13.11                              Segregation of Wastes

13.11.1                        In order to ensure that all waste is disposed of in an appropriate manner, waste should be separated by category on-site by the Contractor. It is recommended that the waste be segregated into the following previously defined categories:

·                excavated material, demolition waste (inert) and construction waste (inert) suitable for re-use on-site and offsite (public fill site);

·                demolition and construction waste (non inert) for landfill;

·                chemical waste; and

·                general refuse (separated and recycled where possible).

13.11.2                        It is recommended that the segregated wastes should then be disposed of as follows:

·                inert demolition/construction waste material when deemed suitable for reclamation or land formation should be re-used on-site;

·                non-inert demolition / construction waste material should be disposed of at landfills;

·                chemical waste as defined by Schedule 1 of the Waste Disposal (Chemical Waste) (General) Regulation, should be stored in accordance with approved methods defined in the Regulation and Code of Practice and the chemical waste disposed of at the Chemical Waste Treatment Facility located at Tsing Yi or an approved recycler;

·                general refuse should be recycled where possible or disposed of at public landfill.

13.12                              Storage, Collection and Transport of Waste

13.12.1                        Reputable waste hauliers should be used to collect and transport the wastes to the appropriate disposal points. The necessary measures to minimise adverse impacts on water quality during the storage, handling and transportation of these wastes should also be instigated. 

13.12.2                        It is recommended that:

·                wastes should be handled and stored in a manner which ensures that they are held securely without loss or leakage thereby minimising the potential for pollution. Release of these potential pollutants into marine waters during storage, handling or barge transportation should not be permitted as introduction of polluted waters is likely to have detrimental effects on water quality and water sensitive receivers;

·                only reputable waste hauliers authorised to collect the specific category of waste concerned should be employed;

·                appropriate measures should be employed to minimise windblown litter and dust during transportation by using enclosed bins, covering trucks or transporting wastes in enclosed containers;

·                the necessary waste disposal permits and registrations should be obtained from the appropriate authorities, if they are required, in accordance with the Waste Disposal Ordinance (Cap 354), Waste Disposal (Chemical Waste) (General) Regulation (Cap 354) and the Crown Land Ordinance;

·                collection of general refuse should be carried out frequently, preferably daily;

·                waste should only be disposed of at licensed sites and the civil engineering contractor should develop procedures to ensure that illegal disposal of wastes does not occur;

·                waste storage areas should be well maintained and cleaned regularly;

·                records should be maintained of the quantities of wastes generated, recycled and disposed, determined by weighing each load or other method; and

·                A “trip ticket” system should be implemented, if required by Government.

13.13                              Biogas Assessment

13.13.1                        Biogas may be generated under anaerobic conditions from existing highly organic sediments and, if any sediments are left in place, there could be a potential risk of methane to subsequent developments on the reclamation.  Within the CRIII area, the sediments have a high organic content (refer to paragraph 10.5 of this EIA Report).  With the ‘fully-dredged’ method to be used for the CRIII project, however, organic sediments will be removed, thus avoiding the risk of any impact from methane.

13.14                              Conclusion

13.14.1                        Review of available sediment quality data indicates that the marine sediments in the proposed CRIII area are likely to be seriously contaminated and as such will require special disposal provisions. The dredged material will therefore not be suitable for conventional disposal at a gazetted marine disposal ground. The future Contractor will finalise the required disposal allocation with the MFC. The mitigation measures recommended in Section 10 of this EIA Report and the Works Branch Technical Circular Nos. 3/2000 and 12/2000 should be strictly followed to minimise any potential adverse impacts of the dredging works and associated sediment disposal, and to protect short term, local water quality.

13.14.2                        Provided that demolition and construction waste arisings are handled, transported and disposed of using approved methods as described previously, and that no solid or liquid wastes enter surrounding marine waters, no significant adverse environmental impacts are envisaged.  Thus, it is anticipated that no insurmountable waste management impacts will arise during the construction period.

 

 


14.                                      Landscape and Visual Assessment

14.1                                  Introduction

14.1.1                            General

14.1.1.1            As stated in Section 1.3.2 of this EIA Report (refer to Chapter 1), under the EIAO TM Schedule 3, Engineering Feasibility Studies with a Study Area >20 Ha require an EIA but do not require Environmental Permits.  The Central Reclamation Phase III Comprehensive Feasibility Study is therefore a Schedule 3 Project (the extent of the study area is illustrated in its entirety by the Conceptual Landscape Master Plan - Figure 14.14 included later in this chapter).

14.1.1.2            The Central Reclamation Phase III project, however, will involve the construction of a number of infrastructure works which are described in detail in Section 1.5 of this EIA Report and illustrated in Figure 1.2 (refer to Chapter 1).  Under the EIAO TM Schedule 2, the following works constructed as part of the CRIII project require an EIA and require Environmental Permits prior to construction:

·                The Reclamation;

·                Primary and Distributor Roads;

·                Central and Wan Chai Bypass ; and

·                North Island Line Protection Works within CRIII.

It should be noted that the structural construction works for the Central and Wan Chai Bypass and North Island Line Protection Works are entrusted works to the CRIII project.  All other aspects of the operation and remaining construction of these projects will be conducted by others who will be responsible for separate EIA reports for these works.

14.1.1.3            The assessment of landscape and visual impacts is controlled through the requirement to address issues as part of the environment review and assessment process.  The requirement for, and approach to, environmental impact assessment generally is regulated by the Environmental Impact Assessment Ordinance (Cap. 499). The prescribed approach to landscape and visual impact assessment is laid down in Annex 10 and 18 of the Technical Memorandum, published as a statutory instrument under Section 16 of the Act.

14.1.2                            Scope and Contents of Landscape and Visual Impact Assessments

14.1.2.1            Study Process

The landscape and visual impact assessment covers the following:

·                a definition of the scope and contents of the study;

·                a baseline study describing the existing landscape and visual character (included as an Appendix to the EIA Study Report);

·                a review of the relevant planning and development control framework (included as an Appendix to the EIA Study Report);

·                impact studies to identify the potential landscape and visual impacts and predict their magnitude and potential significance; and

·                recommendations on mitigation measures.

The manner in which the assessments are conducted takes full account of the special nature of the works and the fact that four elements of the works will require Environmental Permits (refer also to paragraph 14.1.1 above).

14.1.3                            Limits of the Study Area for Landscape and Visual Assessment

14.1.3.1            The limits of the study area are indicated in Figure 14.1 which also illustrates the Baseline Landscape and Visual Character Areas.  The subject site is physically enclosed and visually characterised by the following elements:

·                Northern Boundary - views to the north are dominated by Victoria Harbour and the Kowloon Peninsula.  The harbour resource lends the site an open character which varies according to climate and visibility;

·                Eastern Boundary - the Hong Kong Convention and Exhibition Centre provides an articulated, generally horizontal, visual backdrop which contrasts with the vertical linear facades of the Grand Hyatt Hotel and Central Plaza;

·                Southern Boundary - an ‘urban wall’ of high rise development along the southern edge of Harcourt Road and Connaught Road Central provides a robust and multifaceted backdrop to the site.  Whilst relatively dense, it still allows visual permeability to the mountainous backdrop of Victoria Peak; and

·                Western Boundary - the absence of high rise development north of Jardine House and Exchange Square allows open views across the CRIII to the Macau Ferry Terminal.  The visual character of this area will change dramatically following construction of the proposed No. 2 International Finance Centre (IFC) adjacent to the MTR Hong Kong Station.  This feature will become a dominating element in the district.

For the purposes of discussion, figures and photomontages included in this Chapter, the assumption is made that the Wan Chai Development Phase II Project will be implemented.


14.1.4                            Description of the CRIII Works

14.1.4.1            The key elements of the CRIII project are listed in Section 1.5 of this EIA Report and illustrated in Figure 1.2(refer to Chapter 1).  As part of the Comprehensive Feasibility Study for Minimum Option for CRIII  a planning and urban design study has been conducted to prepare an Outline Development  Plan (ODP) for the CRIII area and part of the adjacent WDII area.  This ODP recommends land uses for the CRIII area but none of the development  will be undertaken as part of the CRIII project excepting those works detailed in Section 1.5 of this EIA Report and illustrated in Figure 1.2 (refer to Chapter 1).  Reference, however, is made to the proposed land uses as required for the landscape and visual impact assessments presented in this chapter.  The ODP is presented in the Planning, Urban Design, Landscape & Visual Impact, Final Study Report. 

14.1.5                            Key Issues to be Addressed

14.1.5.1            The landscape and visual impact assessment identifies the impacts of the CRIII works upon the resources that make up the landscape, upon the character of that landscape and upon the visual amenity of that area.  A clear distinction is drawn between landscape impacts and visual impacts.

14.1.5.2            Key issues relating to the landscape impact of the CRIII works will include:

·                physical impacts upon Victoria Harbour;

·                loss of temporary parks and vegetation;

·                impacts upon the landscape character of the waterfront; and

·                impacts upon ‘landmark’ elements (e.g. “Star” ferry pier and clock tower).

14.1.5.3            Key issues relating to the visual impact of the CRIII works will include:

·                loss of views to Victoria Harbour from development to the east, south and west of the proposed reclamation;

·                loss of southern views to Victoria Peak and the natural green backdrop from Victoria Harbour and Kowloon Peninsula; and

·                loss of visual relationship between Central-Wanchai waterfront and Victoria Harbour.

14.1.6                            Principal View Points

14.1.6.1            Six principal photomontage view points have been identified and agreed with Government to indicate both the existing and the proposed views before and after implementation of the CRIII works.  The locations of the photomontage view points are indicated in Figure 14.2.  Photographic views at the time of preparation of this EIA Report are indicated in Figures 14.3-14.8 and are taken from the following locations:

·                View north from the Peak Tower (at grade);

·                View south to Hong Kong Bank from Victoria Harbour (aerial);

·                View north across Tamar site from Admiralty Centre;

·                View south west from Expo Drive (at grade) taken at existing, day 1, and year 10;

·                View south west from Victoria Harbour (aerial); and

·                View south from “Star” ferry pier Tsim Sha Tsui (at grade).

14.1.7                            Methodology for Assessment of Landscape and Visual Impacts

14.1.7.1            Landscape impacts can be positive or negative.  They are assessed at two levels:

·                impacts upon individual landscape features and resources; and

·                impacts upon landscape character.

14.1.7.2            Landscape impacts are assessed as a function of the magnitude of change and the sensitivity of the landscape resource or landscape character.  Landscape sensitivity is assessed as high, medium or low.  Magnitude of change is assessed as high, moderate or low. Landscape impacts are assessed subsequent to the implementation of prescribed mitigation measures at both construction and operational stages and are termed residual impacts.

14.1.7.3            Landscape sensitivity is the ability of the landscape or character to accommodate change without prejudice to the quality of that resource. Therefore, for example, delicate plant ecosystems will be sensitive to changes in landscape resources whilst landscapes with a diversity of elements will tend to be less sensitive to changes in landscape character.  Additional factors affecting the sensitivity of landscape resources and character, such as the quality and maturity of the landscape resource and character, are also noted when undertaking an assessment.

14.1.7.4            Impacts are assessed as very substantial, substantial, moderate, slight or very slight (positive or negative). Insignificant impacts are termed negligible. A matrix is used to assess landscape impacts and is shown in Table 14.1 below.

Table 14.1 : Landscape Impact Characteristic (Positive or Negative)

 

Sensitivity of Landscape Resource / Character

Magnitude of Change

High

Medium

Low

Negligible

High

Very Substantial to Substantial

Substantial to Moderate

Moderate to Slight

Negligible

Moderate

Substantial to Moderate

Moderate to Slight

Slight to Very Slight

Negligible

Low

Moderate to Slight

Slight to Very Slight

Very Slight to Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

14.1.7.5            Visual impacts can be positive or negative and are defined as a function of the sensitivity of a receiver and the magnitude of the change to that receiver’s existing view.

14.1.7.6            The assessment of visual impacts is structured by receiver sensitivity. Visually Sensitive Receivers (VSRs) are identified through the definition of the development’s zone of visual influence or ZVI. (i.e. the area within which views of the development are possible). For the purpose of this study, receivers have been grouped into the following categories:

Residential

-

Those people who would view the scheme from their home

Occupational

-

Those people who would view the scheme from their workplace

Travellers

-

Those people who would view the scheme from their vehicles or on foot

Recreational

-

Those people who would view the scheme whilst engaging in recreational activities

14.1.7.7            The sensitivity of receivers to visual impacts is influenced by the immediate context of the viewer, the activity in which they are engaged and the value that they attach to this location in particular. Additional factors affecting the sensitivity of VSRs, such as size of population in the VSR group to be affected and existing view quality of the VSR, availability and amenity of alternative views, are taken into account.  Receivers are categorised as being of high, medium or low sensitivity to visual impacts.

14.1.7.8            Those who view the scheme from their homes are considered to be highly sensitive to any visual intrusion. This is because the attractiveness, or otherwise, of the view would have a notable effect on a resident’s general quality of life and acceptability of their home environment.

14.1.7.9            Those people who view the scheme from their workplace are considered relatively less sensitive to visual intrusion. This is because they are employed in activities where visual outlook plays a less important role in the perception of the quality of the working environment. They are classified as a low sensitivity group.

14.1.7.10        For those who view the scheme whilst engaging in outdoor leisure pursuits, visual sensitivity varies depending on the type of recreational activity. Those taking a stroll in a park, for example, would be classified as a high sensitivity group compared to football players who would have a low sensitivity rating.

14.1.7.11        For those people who view the scheme from public thoroughfares, the degree of visual intrusion experienced depends on the speed of travel and whether views are continuous or only occasional. Generally, the slower the speed of travel and the more continuous the viewing experience, then the greater the degree of sensitivity.


14.1.7.12        The criteria used to determine the magnitude of change to a view are given below:

·                duration of change;

·                degree of change of views; and

·                proximity of receivers.

14.1.7.13        Impacts are assessed as very substantial, substantial, moderate, slight or very slight.. Insubstantial impacts are termed negligible. A matrix is used to assess visual impacts and is shown in Table 14.2 below.

Table 14.2 :  Visual Impact Characteristic (Positive or Negative)

 

Sensitivity of Receiver Group

Magnitude of Change

High

Medium

Low

Negligible

High

Very Substantial to Substantial

Substantial to Moderate

Moderate to Slight

Negligible

Moderate

Substantial to Moderate

Moderate to Slight

Slight to Very Slight

Negligible

Low

Moderate to Slight

Slight to Very Slight

Very Slight to Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

14.2                                  Baseline Study – Description of the Environment within the CRIII Works Area

14.2.1                            Baseline Study

14.2.1.1            A baseline study focusing on the existing landscape and visual characteristics of the CRIII works area is presented in Appendix T.  This baseline study concluded that the existing CRIII works area is highly fragmented and comprises components which are transitional in nature.  There is a lack of physical and visual integration between the open underdeveloped eastern character zones and the older western areas.  Streetscape is generally of a low quality and suffers from a lack of mature landscape planting.  Public access to the harbour edge is generally lacking and the two temporary parks are poorly executed and maintained.  Due to physical obstructions along the sea walls, views within the site are generally internalised and are more focused upon urban development to the south than upon the harbour resource.  There remains visual permeability within the Central - Wan Chai skyline especially through Statue Square and Harcourt Garden to Wan Chai Gap.  Generally, however, the study area comprises a series of unrelated architectural elements fragmented with numerous physically prominent utility features and temporary civil works.  Little or no coherence is derived from the surrounding urban environment nor is advantage taken of the few positive aspects of the site


14.3                                  Planning and Development Control Framework

14.3.1                            Planning and Development Control Framework

A review of the various statutory and non statutory controls (including previous Government Studies) pertinent to the CRIII works area which affect landscape and visual impacts is provided in Appendix U.

This review includes information on:

·                Metroplan (October 1999);

·                Central & Wan Chai Reclamation Development: Development of Urban Design Parameters (DUDPs) – (October 1993);

·                Hong Kong Island West Development Statement; and

·                The Draft Outline Zoning Plan (No. S/H24/3).

Whilst a small area of Public Transport Facilities will be constructed behind Piers 4 - 7 as aprt of the CRIII works (within the area of the Outline Zoning Plan No. S/H4/9, the facilities essentially and modification of exisitng facilities.  The review of this  Outline Zoning Plan has essentially not been included in Appnedix U.

14.3.2                            Impacts upon the Draft Outline Zoning Plan (No. S/H 24/3)

According to layouts discussed in the later Sections 14.4 and 14.5 of this chapter, the Designated Projects (DP1-4) conform to the planned use on the relevant OZP and therefore no further action under the Town Planning Ordinance is required.

14.4                                  Landscape Impact Assessment

14.4.1                            Introduction

This Landscape Impact Assessment is concerned with impacts attributable to the 4no. individual Schedule 2 Projects in addition to the Schedule 3 Project.  Readers of this Landscape Impact Assessment should familiarise themselves with the Baseline Study – Description of the Environment within the CRIII Works Area – presented in Appendix T.

An assessment of landscape impacts attributable to the overall development, as a Schedule 3 project, is thereafter presented in paragraph14.4.6.

14.4.2                            Designated Project 1 – Reclamation

14.4.2.1            Introduction

This Landscape Impact Assessment will include assessment of impacts attributable to the reclamation, new sea walls, cooling water pumping stations, ferry piers and public landing steps, as all these items form an integral part of the “reclamation”.  The Layout Plan and Section of Designated Project 1 is shown on Figure 14.9.

14.4.2.1.1                                                                                                                                                                                                                                         Sources of Landscape Impacts for Reclamation – Construction Stage

The sources of construction stage impacts upon landscape character and landscape resources, attributable to the reclamation, will include:

·                the physical process of reclaiming 18ha of new land in the harbour through importing fill material by barge;

·                the demolition of the existing "Star" Ferry Pier;

·                the demolition of existing public open space and landscaped area adjacent to the "Star" Ferry Pier;

·                the construction of temporary and permanent sea walls and drainage channels;

·                the construction of cooling water pumping stations;

·                the construction of “Star” ferry piers and public landing steps.  These structures will comprise 2no. piers per development with the “Star” ferry piers located at the end of the Statue Square Open Space Corridor and the Public Landing Steps located at the end of the Historic Corridor. Neither development is indicated in figures included in this Chapter due to their layout being unconfirmed at the time of study;

·                temporary site areas for storage, plant, cabins and associated site equipment; and

·                temporary construction arrangements  that affect access to adjacent areas.

14.4.2.2            Sources of Landscape Impacts for Reclamation – Operation Stage

14.4.2.2.1                The sources of operational stage landscape impacts will include :

·                existence of 18ha of new land in the harbour;

·                existence of new sea walls and cooling water pumping stations (submerged); and

·                existence of new “Star” ferry piers and public landing steps.

14.4.2.2.2                Landscape Mitigation Measures for Reclamation – Construction Stage

Construction stage landscape mitigation measures should include:

·                minimising contractors accesses and working areas as far as possible;

·                sensitively designed site hoarding to reduce impacts upon landscape character from dredging, filling and the construction of sea walls;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation where practicable;

·                protection and retention of existing vegetation where possible in accordance with the Hong Kong Government ‘A Guide to Tree Planting and Maintenance in Urban Hong Kong, Section 5 ‘Care of Trees on Development Sites’ and the Country Parks Ordinance;

·                transplanting of trees where appropriate;

·                advance planting;

·                conservation of top soil,if present; and

·                design of the temporary works areas so as to optimise eventual use as promenade and public open space.

14.4.2.2.3 Landscape Mitigation Measures for Reclamation - Operation Stage

Operation stage landscape mitigation measures should include:

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation where practicable and not implemented during the Construction Stage;

·                sensitive seawall design to enhance the recreational value of the future promenade;

·                removal of all debris from reclamation and maintaining that surfaces are even; and

·                hydroseeding of reclamation, as appropriate, at formed sites awaiting development or areas likely to be unused for a long period.  These areas would be subject to ongoing irrigation and maintenance to ensure that vegetation cover is complete.  For land pending for development / construction for more than nine months, hydroseeding should include a mixture of perennial flowers.

14.4.2.2.4                Prediction and Evaluation of Landscape Impacts for Reclamation

Residual landscape impacts (i.e. impacts which remain after mitigation measures have been implemented) at construction and operation stages for reclamation are indicated in Table 14.3.  Conclusions and recommendations for landscape and visual impacts associated with reclamation are indicated in paragraph 14.5.2.9.

 

 


Table 14.3 : Residual Landscape Impacts from Reclamation

Landscape Character Zone (1-17)

 

Source of Impact

Type of Impact

Magnitude of Change at Main Project Stages

Landscape Sensitivity

Residual Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Residual Impact Characteristic during Operation Phase after Implementation of Mitigation Measures

 

 

 

Construction

Operation

 

 

 

The Servicemen’s Guides Association (1)

Reclamation

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Negative

Citic Tower (2)

Reclamation

C

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Lung Wui Road (3)

Reclamation

C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Negative

Tim Mei Avenue and Tim Wa Avenue (4)

Reclamation

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Formar Tamar Basin (5)

Reclamation

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Connaught Road Central/ Harcourt Road (6)

Reclamation

C

Moderate

Low

Low

Slight to Very Slight Negative

Very Slight  to Negligible Negative

Heliport (7) (to be relocated prior to completion of reclamation)

Reclamation

R,C

High

N/A

Low

Moderate to Slight Negative

N/A

Temporary Park (adjacent to Central Barracks (8) (to be relocated prior to completion of reclamation)

Reclamation

R,C

High

N/A

Medium

Substantial to Moderate Negative

N/A

Central Barracks  (9)

Reclamation

C

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Queen’s Pier/ Edinburgh Place (10) (to be relocated prior to completion of reclamation)

Reclamation & Demolition

R,C

High

N/A

Low

Moderate to Slight Negative

N/A

City Hall and garden (11)

Reclamation & Demolition

C

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Northern Areas of Statue Square adjacent to Connaught Rd (12)

Reclamation & Demolition

C

Low

Negligible

High

Moderate to Slight Negligible

Negligible

“Star” Ferry Car Park (13)

Reclamation & Demolition

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Star Ferry Pier (14)  (to be relocated prior to completion of reclamation)

Reclamation & Demolition

R, C

High

N/A

Medium

Substantial to Moderate Negative

N/A

General Post Office (15)

Reclamation & Demolition

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Eastern Edge of Central Reclamation Phase I (Man Yiu Street) (16)

Reclamation & Demolition

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Negative

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Reclamation

R

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial negative

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Reclamation

C

High

High

High

Very Substantial to Substantial Negative

Substantial to Moderate Negative

Key :    Type of  Impact                                                      =          R – Impact on Landscape Resources

                                                                                        =          C – Impact on Landscape Character

            Magnitude of Impact                                               =          Negligible, Low, Moderate or High

            Landscape Sensitivity                                            =          Low, Medium or High

            Impact Characteristic                                             =          Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative) 

 

 

 


14.4.3                            Designated Project 2 – Primary & District Distributor Roads

14.4.3.1            Introduction

The assessment for primary and district distributor roads will include assessment of impacts attributable to the roads, drainage, utilities and other services associated with the road reserves.  The Layout Plan and Section of Designated Project 2 is shown on Figure 14.10.

14.4.3.1.1 Sources of Landscape Impacts from Primary & District Distributor Roads – Construction Stage

The sources of construction stage landscape impacts will include:

·                road construction on existing and proposed reclamation;

·                temporary construction arrangements which will affect access to adjacent areas; and

·                designation of temporary site areas for storage, plant, cabins, and associated site equipment.

14.4.3.1.2 Sources of Landscape Impacts for Primary & District Distributor Roads – Operation Stage (Note that no noise barriers will be required).

The sources of operation stage landscape impacts will include:

·                existence of Primary, Distributor, and District Distributor Roads, and their associated landscape framework; and

·                the road corridors as a physical edge, which separates the waterfront from the hinterland.

14.4.3.1.3 Landscape Mitigation Measures for Primary & District Distributor Roads – Construction Stage
14.4.3.1.4                Construction stage landscape mitigation measures should include:

·                minimising contractors accesses and working areas as far as possible;

·                sensitively designed site hoarding to reduce impacts upon landscape character from the construction works of Primary, Distributor and District Distributor Roads, and associated drainage and construction works;

·                protection and retention of existing vegetation where possible in accordance with the Hong Kong Government ‘A Guide to Tree Planting and Maintenance in Urban Hong Kong, Section 5 ‘Care of Trees on Development Sites’ and the Country Parks Ordinance;

·                transplanting of trees where appropriate;

·                advance planting; and

·                conservation of top soil, if present.

14.4.3.1.5 Landscape Mitigation Measures for Primary & District Distributor Roads – Operation Stage

Operation stage landscape mitigation measures should include:

·                new roads to incorporate suitable streetscape amenity and landscape planting, where practical,  to minimise visual and environmental impacts.  It is proposed that the street hierarchy be reinforced via the selection of different tree species for different roads.  It is, however, suggested that the street tree palette be limited to three species used to distinguish roads of similar character;

·                existing roads upgraded, where practical, to ‘marry’ with the proposed landscape framework; and

·                provision of a landscape deck to improve pedestrian circulation between waterfront and hinterland.

14.4.3.1.6                Prediction and Evaluation of Landscape Impacts for Primary & District Distributor Roads

Residual landscape impacts (i.e. impacts which remain after mitigation measures have been implemented) at construction and operation stages for Primary and District Distributor Roads are indicated in Table 14.4.  Conclusions and recommendations for landscape and visual impacts associated with Primary and District Distributor Roads are indicated in paragraph 14.5.3.7.

 

 


Table 14.4 :  Residual Landscape Impacts from Primary and Distributor Roads

Landscape Character Zone (1-17)

(Refer to Figure 14.10a)

Source of Impact

Type of Impact

Magnitude of Change at Main Project Stages

Landscape Sensitivity

Residual Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Residual Impact Characteristic during Operation Phase after Implementation of Mitigation Measures

 

 

 

Construction

Operation

 

 

 

Existing Character Zone

 

 

 

 

 

 

 

The Servicemen’s Guides Association (1)

Road Construction & Operation

C

Low

Low

Low

Very Slight  to Negligible Negative

Very Slight  to Negligible Negative

Citic Tower (2)

Road Construction & Operation

C

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Lung Wui Road (3)

Road Construction & Operation

R,C

Low

Low

Low

Very Slight  to Negligible Negative

Very Slight  to Negligible Negative

Tim Mei Avenue and Tim Wa Avenue (4)

Road Construction & Operation

R,C

Low

Low

Low

Very Slight  to Negligible Negative

Very Slight  to Negligible Negative

Formar Tamar Basin (5)

Road Construction & Operation

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Connaught Road Central/ Harcourt Road (6)

Road Construction & Operation

C

Moderate

Low

Low

Slight to Very Slight Negative

Very Slight  to Negligible Negative

Heliport (7) (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Low

N/A

N/A

Temporary Park (adjacent to Central Barracks  (8) (to be relocated prior to completion of reclamation)

Road Construction & Operation

N/A

N/A

N/A

Medium

N/A

N/A

Central Barracks  (9)

Road Construction & Operation

C

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Queen’s Pier/ Edinburgh Place (10) (to be relocated prior to completion of reclamation)

N/A

N/A

Low

N/A

Low

N/A

N/A

City Hall and garden (11)

Road Construction & Operation

C

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Northern Areas of Statue Square adjacent to Connaught Rd (12)

Road Construction & Operation

C

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

“Star” Ferry Car Park (13)

Road Construction & Operation

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Star Ferry Pier (14)   (to be relocated prior to the completion of reclamation)

N/A

N/A

N/A

N/A

Medium

N/A

N/A

General Post Office (15)

Road Construction & Operation

C

High

Moderate

Low

Moderate to Slight Negative

Slight to Very Slight Negative

Eastern Edge of Central Reclamation Phase I (16)

Road Construction & Operation

C

Low

Low

Low

Very Slight  to Negligible Negative

Very Slight  to Negligible Negative

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Road Construction & Operation

R

Negligible

Negligible

Low

Negligible

Negligible

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Road Construction & Operation

C

Negligible

Negligible

Low

Negligible

Negligible

Proposed Character Zone

 

 

 

 

 

 

 

Waterfront Promenade (G)

Road Operation

C

N/A

Negligible

High

N/A

Negligible

Promenade Park (M)

Road Operation

C

N/A

Negligible

High

N/A

Negligible

Statue Square  Open Spasce Corridor (C)

Road Operation

C

N/A

Negligible

High

N/A

Negligible

The Historic Corridor  (D)

Road Operation

C

N/A

 Moderate

 Medium

N/A

 Moderate to Slight  Negative

City Hall Memorial Garden   (E)

Road Operation

C

N/A

 Low

High

N/A

Moderate to Slight Negative

Festival Market  (F)

Road Operation

C

N/A

Negligible

High

N/A

Negligible

Marine Basin (K)

Road Operation

C

N/A

Negligible

High

N/A

Negligible

The Arts & Entertainment Corridor (L)

Road Operation

C

N/A

Low

High

N/A

 Moderate to Slight  Negative

Key :       Type of  impact                                                                            =              R - Impact on Landscape Resources

                                                                                                                     =              C – Impact on Landscape Character

                Magnitude of Change at Main Project Stages                              =              Negligible, Low, Moderate or High

                Landscape Sensitivity                                                                   =              Low, Medium or High

                Impact Characteristic                                                                    =              Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative)


14.4.4                            Designated Project 3 – Central-Wan Chai Bypass Tunnel

14.4.4.1            Introduction

Only the construction phase impacts for this designated project will be considered as only the construction works are entrusted to the CRIII project. The operation phase impacts are being assessed by HyD/MWO under a separate EIA Study.  The Layout Plan and Section of Designated Project 3 is shown on Figure 14.11.

14.4.4.1.1 Sources of Landscape Impacts for Central-Wan Chai Bypass Tunnel – Construction Stage

The sources of construction stage landscape impacts will include:

·                construction of cut and cover tunnel;

·                designation of temporary site areas for storage, plant, cabins and associated site equipment; and

·                temporary construction arrangements that effect access to adjacent areas.

14.4.4.1.2 Landscape Mitigation Measures for Central-Wan Chai Bypass Tunnel – Construction Stage
Construction stage landscape mitigation measures should include:

·                minimising contractors accesses and working areas as far as possible;

·                sensitively designed site hoarding to reduce impacts upon landscape character from the excavation of the cut and cover tunnel;

·                advance planting; and

·                design of the temporary works areas so as to optimise eventual uses.

14.4.4.1.3 Prediction and Evaluation of Landscape Impacts for Central-Wan Chai Bypass Tunnel

Residual landscape impacts (i.e. impacts which remain after mitigation measures have been implemented) at the construction stage for Central-Wan Chai Bypass Tunnel are indicated in Table 14.5.  Conclusions and recommendations for landscape and visual associated with the Central-Wan Chai Bypass are indicated in paragraph 14.5.4.7.

 

 

 

 


Table 14.5 :  Residual Landscape Impacts from Central-Wan Chai Bypass Tunnel

 

Landscape Character Zone (1-17)

 

Source of Impact

Type of Impact

Magnitude of Change at Main Project Stages

Landscape Sensitivity

Residual Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Residual Impact Characteristic during Operation Phase after Implementation of Mitigation Measures

 

 

 

Construction

Operation

 

 

 

The Servicemen’s Guides Association (1)

Tunnel Construction

C

Low

N/A

Low

Very Slight  to Negligible Negative

N/A

Citic Tower (2)

Tunnel Construction

C

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Lung Wui Road (3)

Tunnel Construction

C

Low

N/A

Low

Very Slight  to Negligible Negative

N/A

Tim Mei Avenue and Tim Wa Avenue (4)

Tunnel Construction

C

Low

N/A

Low

Very Slight  to Negligible Negative

N/A

Formar Tamar Basin (5)

Tunnel Construction

C

High

N/A

Low

Moderate to Slight Negative

N/A

Connaught Road Central/ Harcourt Road (6)

Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

Heliport (7)  (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Low

N/A

N/A

Temporary Park (adjacent to Central Barracks  (8) (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Medium

N/A

N/A

Central Barracks  (9)

Tunnel Construction

C

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Queen’s Pier/ Edinburgh Place (10) (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Low

N/A

N/A

City Hall (11)

Tunnel Construction

C

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Northern Areas of Statue Square adjacent to Connaught Rd (12)

Tunnel Construction

C

Ngeligible

N/A

High

Negligible

N/A

“Star” Ferry Car Park (13)

Tunnel Construction

C

Low

N/A

Low

Very Slight  to Negligible Negative

N/A

"Star" Ferry Pier (14)  (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Medium

N/A

N/A

General Post Office (15)

Tunnel Construction

C

High

N/A

Low

Moderate to Slight Negative

N/A

Eastern Edge of Central Reclamation Phase I (16)

Tunnel Construction

C

Low

N/A

Low

Very Slight  to Negligible Negative

N/A

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Tunnel Construction

R

Negligible

N/A

Low

Negligible

N/A

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Tunnel Construction

C

Negligible

N/A

Low

Negligible

N/A

Key :    Type of  Impact                                                      =          R – Impact on Landscape Resources

                                                                                        =          C – Impact on Landscape Character

            Magnitude of Impact                                               =          Negligible, Low, Moderate or High

            Landscape Sensitivity                                            =          Low, Medium or High

            Impact Characteristic                                             =          Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative)

 

 


14.4.5                            Designated Project 4 – North Island Line Protection Works within CRIII

14.4.5.1            Introduction

Only the construction phase impacts for the designated project will be considered as only the construction works are entrusted to the CRIII project.  The operation phase impacts has, however, been assessed as negligible as the works are totally below ground.  These impacts for the North Island  line  are being undertaken by the MTRC under a separate EIA Study.  The Layout Plan and Section of Designated Project 4 is shown on Figure 14.12.

14.4.5.2            Sources of Landscape Impacts for North Island Line Protection Works within CRIII – Construction Stage

The sources of construction stage landscape impacts will include:

·                construction of cut and cover tunnel and railway station structural envelope;

·                designation of temporary site areas for storage, plant, cabins and associated site equipment; and

·                temporary construction arrangements that effect access to adjacent areas.

14.4.5.3            Landscape Mitigation Measures for North Island Line Protection Works within CRIII – Construction Stage

Construction stage landscape mitigation measures should include:

·                minimising contractors accesses and working areas as far as possible;

·                sensitively designed site hoarding to reduce impacts upon landscape character from the excavation of the cut and cover tunnel;

·                advance planting; and

·                design of the temporary works areas so as to optimise eventual uses, such as promenade and public open spaces.

14.4.5.1            Prediction and Evaluation of Landscape Impacts for North Island Line Protection Works within CRIII

Residual landscape impacts (i.e. impacts which remain after mitigation measures have been implemented) at the construction stage for the North Island Line Protection Works within CRIII are indicated in Table 14.6.  Conclusions and recommendations for landscape and visual impacts associated with the North Island Line Protection Works within CRIII are indicated in paragraph 14.5.5.7.

 

 

 


Table 14.6 :  Residual Landscape Impacts from North Island Line Protection Works within CRIII

Landscape Character Zone (1-17)

 

Source of Impact

Type of Impact

Magnitude of Change at Main Project Stages

Landscape Sensitivity

Residual Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Residual Impact Characteristic during Operation Phase after Implementation of Mitigation Measures

 

 

 

 

Construction

Operation

 

 

 

 

The Servicemen’s Guides Association (1)

Railway Station Structural Envelope & Tunnel Construction

C

High

N/A

Low

Moderate to Slight Negative

N/A

 

Citic Tower (2)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Medium

Slight to Very Slight Negative

N/A

 

Lung Wui Road (3)

Railway Station Structural Envelope & Tunnel Construction

C

High

N/A

Low

Moderate to Slight Negative

N/A

 

Tim Mei Avenue and Tim Wa Avenue (4)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

 

Formar Tamar Basin (5)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

 

Connaught Road Central/ Harcourt Road (6)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

 

Heliport (7) (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Low

N/A

N/A

 

Temporary Park (adjacent to Central Barracks (8) (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Medium

N/A

N/A

 

Central Barracks  (9)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Medium

Slight to Very Slight

Negative

N/A

 

Queen’s Pier/ Edinburgh Place (10) (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Low

N/A

N/A

 

 

City Hall (11)

Railway Station Structural Envelope & Tunnel Construction

C

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Northern Areas of Statue Square adjacent to Connaught Rd (12)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

High

Very Slight to Negligible Negative

N/A

 

“Star” Ferry Car Park (13)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

 

"Star" Ferry Pier (14)  (to be relocated prior to completion of reclamation)

N/A

N/A

N/A

N/A

Medium

N/A

N/A

 

General Post Office (15)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

 

Eastern Edge of Central Reclamation Phase I (16)

Railway Station Structural Envelope & Tunnel Construction

C

Low

N/A

Low

Very Slight to Negligible Negative

N/A

 

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Railway Station Structural Envelope & Tunnel Construction

R

Negligible

N/A

Low

Negligible

N/A

 

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Railway Station Structural Envelope & Tunnel Construction

C

Negligible

N/A

Low

Negligible

N/A

 

Key :        Type of  Impact                                                                              =              R – Impact on Landscape Resources

                                                                                                                     =              C – Impact on Landscape Character

                Magnitude of Impact                                                                        =              Negligible, Low, Moderate or High

                Landscape Sensitivity                                                                      =              Low, Medium or High

                Impact Characteristic                                                                       =              Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative) 


14.4.6                            Schedule 3 Project – Engineering Feasibility Study for CRIII and Future Development on CRIII Site.

14.4.6.1            Introduction

14.4.6.1.1 The assessment seeks to address potential landscape impacts which may be caused by CRIII.  Sources of impact will initially be construction-based.  Long term impacts will result from permanent changes to the landscape character of the study area.  Landscape impacts are indicated in Table 14.7.
14.4.6.1.2 Reclamation will be the cause of both landscape impacts and opportunities for landscape mitigation.  Reclamation is associated with negative landscape impacts, primarily the loss of 18ha of Victoria Harbour.  The areas of reclamation will, however, also create opportunities for mitigation through landscape planting and provision of amenity space.
14.4.6.1.3                A separate Landscape Assessment for the ventilation shafts which will be constructed as part of the Hong Kong Station Extend Overrun Tunnel construction, is included as Appendix V.  Direct reference to these structures is therefore not included in this section.  It should be noted that this report is included for information only to allow the reader a complete understanding on the overall scope of the works within the CRIII reclamation site.

14.4.6.2            Sources of Landscape Impacts

Construction Stage

14.4.6.2.1 The sources of construction stage landscape impacts will include:

·                the physical process of site clearance of key developments, namely City Hall (High Block only), General Post Office, Star Ferry Pier and Queens Pier;

·                the construction works of principal infrastructure development, namely reclamation, Primary, Distributor and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and North Island Line Protection Works;

·                designation of temporary site areas for storage, plant, cabins and associated site equipment;

·                temporary construction arrangements that affect access to adjacent areas; and

·                the construction works of key developments, namely CDA Groundscraper, Festival Market, Central Government Complex, parks, plazas, marine basin, and open space corridors.

Operational Stage

14.4.6.2.2                                                                                                                                                                                                                                         The sources of operational stage landscape impacts will include all the various components of the proposed reclamation development.  These will, by their varying nature, tend to act as sources of both negative and positive impacts and will include:

·                existence of 18ha of new land in the harbour;

·                existence of Primary, Distributor, and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and the North Island Line Station and Tunnels;

·                new building developments including the CDA Groundscraper, Festival Market, and Central Government Complex;

·                establishment of a network of open spaces providing for a range of functions including pedestrian circulation and as a venue for civic and community events;

·                the creation of major landscape spaces forming pedestrian arteries linking the waterfront with existing open spaces and other areas of the city;

·               the establishment of an integrated, pedestrian oriented streetscape which will enhance pedestrian movement, integrate the proposed and existing developments within an overall landscape framework and generally improve the quality of  the public environment;

·                the provision of buffer areas to mitigate negative environmental conditions; and

·                the creation of a high quality, international standard waterfront park which will provide a unifying edge to the city ultimately stretching between the Hong Kong Convention Centre in the east to the Hong Kong Station Express Terminal in the west.  The landscape design of the park will:

-    integrate public gathering spaces for festivals and celebrations;

-    provide a sanctuary from the bustling city environment;

-    give to the city and its citizens an unrivalled passive recreational open space with spectacular views across the ever-changing harbour;

-    provide a prestigious address to existing developments in the surrounding urban areas;

-    provide an appropriate setting for Hong Kong’s new Civic and Cultural Buildings; and

-    provide major new pedestrian arteries in the form of ‘green’ land bridges spanning local and arterial roadways, between urban spaces within the existing urban area and the new reclamation waterfront park. 

14.4.6.3            Prediction and Evaluation of Landscape Impacts

Construction Stage

14.4.6.3.1                The landscape impacts in the construction stage will include impacts upon landscape resources and landscape character. The impacts include:

·                very substantial to substantial negative impacts upon the existing landscape resource and character of Victoria Harbour through 18ha reclamation;

·                moderate to negligible negative impacts upon the existing landscape character of the study area by the construction of Primary, Distributor and District Distributor Roads,

·                moderate to negligible negative impacts upon the existing landscape character of the study area by the construction of the Central-Wan Chai Bypass Tunnel;

·                moderate to negligible negative impacts upon the existing landscape character of the study area by the construction of the North Island Line Protection Works;

·                substantial negative impacts upon the existing landscape character of the study area by construction works of key developments, namely CDA Groundscraper, Festival Market, Central Government Complex, parks, plazas, marine basin, and1 open space corridors;

·                substantial negative impacts upon the existing waterfront resource and character due to reclamation and use of waterfront for construction accesses and staging areas;

·                substantial negative impacts upon streetscape and sitting out areas within the study area due to demolition and construction operations.  Two sitting out areas (combined approximate size 0.75 ha) and 300 No. trees approximately will be affected.  It should be noted that the vast majority of the trees will be transplanted.

·                substantial negative impacts upon landscape resources due to the loss of amenity facilities, including the “Star” Ferry Pier pedestrian plaza (which will be reprovisioned with a new pier prior to demolition), City Hall Memorial Garden and two temporary parks (located on the northern boundary of the Central Barracks and on the eastern edge of the New Ferry Piers reclamation). 

Operational Stage

14.4.6.3.2 The landscape impacts in the operational stage will include impacts upon landscape resources and landscape character.  The impacts include:

·                very substantial negative impacts upon landscape character and resources due to the implementation of 18ha of new land in the harbour;

·                very substantial negative impacts upon landscape character and resources due to the loss of 18ha of Victoria Harbour through reclamation

·                substantial negative impacts upon landscape character due to existence of Primary, Distributor, and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and the North Island Line Station and Tunnels;

·                moderate negative impacts upon landscape character due to new building developments including the CDA Groundscraper, Festival Market, and Central Government Complex;

·                very substantial positive impacts upon landscape character and resources due to the implementation of the Waterfront Park, which will include, but not be limited to, the following elements:

-    a waterfront promenade ultimately stretching from the HKCEC to the Hong Kong Station Express Terminal;

-    a major plaza (Clock Tower Plaza);

-    a festival market forecourt;

-    two smaller parks and a smaller plaza; and

-    international standard quality of hardworks, softworks, street furniture and lighting.

·                very substantial positive impacts upon landscape character and resources due to the implementation of the Statue Square Open Space Corridor, which will include, but not be limited to, the following elements:

-    an elevated deck acting as a major pedestrian artery comprising feature tree and shrub planting;

-    sunken plazas and transition points;

-    co-ordinated integration with commercial developments along the western edge; and

-    dramatic water feature and sculptural elements.

·                very substantial positive impacts upon landscape character and resources due to the implementation of the Historic Corridor, which will include, but not be limited to, the following elements:

-    a tree-lined boulevard with wide footpaths linking the LegCo Building with the new waterfront;

-    reconfigured Memorial Garden at City Hall; and

-    unified and consistent themes in hard materials and planting design.

·                very substantial positive impacts upon landscape character and resources due to the implementation of the Civic Corridor, which will include, but not be limited to, the following elements:

-    a large civic plaza defined by formal canopy trees and bold paving patterns;

-    dramatic water features; and

-    co-ordinated design with proposed civic buildings to reinforce the nodal civic importance of the area.

·                very substantial positive impacts upon landscape character and resources due to the implementation of the Arts and Entertainment Corridor, which will include, but not be limited to, the following elements:

-    a unique basin area providing the focus of existing and proposed cultural facilities integrating with the Waterfront Park promenade;

·                very substantial positive impacts upon landscape character and resources due to the implementation of a Streetscape Network, which will include, but not be limited to, the following elements:

-    unification and integration of the area through consistent use of simple paving materials, street tree planting and shaded promenades;

-    co-ordinated set of street furniture items, including seating, lighting, bollards, barriers and litter bins;

-    reinforcement of street hierarchy by use of different tree species on different roads, limited to an overall street tree palette of three species.

·                very substantial positive impacts upon landscape character and resources due to the implementation of Landscape Decks, which will include, but not be limited to, the following elements:

-    pedestrian connectivity to the waterfront spanning Road P2;

-    landscape elements, including paving patterns and planting, to extend across the landscape decks thereby visually softening the structures and providing further amenity.

·                very substantial positive impacts upon landscape character and resources due to the implementation of Supplementary Landscape Spaces, which will include, but not be limited to, the following elements:

-    additional landscaped areas within adjoining development sites incorporating consistent design themes which maintain the overall character of the area without compromising the identity of individual developments.

·                very substantial positive impacts upon landscape character and resources due to the upgrading of streetscape and sitting out areas within the study area; and

·                very substantial positive impacts upon the landscape character of Victoria Harbour due to 18ha of reclamation and the subsequent development of an international style Waterfront Park.

14.4.6.4            Landscape Mitigation Measures

14.4.6.4.1 Generally, the landscape mitigation measures seek to minimise potential impacts of development, to reinstate vegetation that would be lost, to blend the edges of the new development into the landscape pattern of the surrounding area, and provide compensation in the form of environmental improvements such as road-side and reclamation planting to off-set the adverse effects of the project. 
14.4.6.4.2 The Landscape Concept Plan and Conceptual Landscape Master Plan are indicated in Figures 14.13 and 14.14 respectively.  The plans aim to provide the maximum level of landscape and visual mitigation for the study area and, in so doing, result in predominantly positive landscape and visual impacts at the operational stage.  Typical sections through the Waterfront Promenade, Statue Square Open Space Corridor and general streetscape, indicating mitigation through design principles, are illustrated in Figures 14.15 -14.17.
14.4.6.4.3 The design and implementation of CRIII aims to upgrade the existing baseline conditions of the study area and provide a major regional and territorial landscape resource, implemented to an international standard.  

Construction Stage

14.4.6.4.4 Construction stage landscape mitigation measures should include:

·                minimising contractors accesses and working areas as far as possible;

·                sensitive design of civil engineering works to note the design requirement of landscape mitigation measures and help facilitate their successful implementation;

·                sensitively designed site hoarding to reduce impacts upon landscape character from the construction works of principal infrastructure development, namely reclamation, Primary, Distributor and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and the North Island Line Protection Works;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation where practicable;

·                protection and retention of existing vegetation where possible in accordance with the Hong Kong Government ‘A Guide to Tree Planting and Maintenance in Urban Hong Kong, Section 5 ‘Care of Trees on Development Sites’ and the Country Parks Ordinance;

·                transplanting of trees where appropriate;

·                advance planting;

·                conservation of top soil; and

·                design of the temporary works areas so as to optimise eventual use as promenade and public open space.

Operation Stage

14.4.6.4.5 Operation stage landscape mitigation measures should include:

·                implementation of all proposed open spaces including the Waterfront Promenade, Statue Square Corridor, Historic Corridor, Civic Corridor, Streetscape Network, Landscape Decks, and Supplementary Landscape Spaces (refer to Figures 14.15 - 14.17 and photomontages included in paragraph 14.5.6.6.2 of this report);

·                provision of a legible, integrated pedestrian circulation system linking major activity nodes, reinforcing links with adjoining areas, and providing an international quality hard and soft landscape treatment;

·                provision of a grade separated pedestrian system to minimise vehicular/ pedestrian conflict;

·                provision of an integrated network of local and regional open spaces for passive and active recreation;

·                overall enhancement of the landscape resource and character of Victoria Harbour;

·                preservation of selected architectural features, such as the “Star” Ferry Pier clock;

·                preservation of existing significant vegetation, principally the two Banyan Trees flanking the Tamar Site;

·                new roads to incorporate suitable streetscape amenity and landscape planting to minimise visual and environmental impacts; and

·                existing roads upgraded to ‘marry’ with the proposed landscape framework.

14.4.6.5            Residual Landscape Impacts

14.4.6.5.1 A residual landscape impact is defined as a negative impact which cannot be mitigated after all practical methods of mitigation have been implemented.  The loss of 18 ha of Victoria Harbour will remain as a residual landscape impact, as a similar volume and area of water has not been reinstated as part of the landscape proposals. The provision of an international quality harbour edge and public promenade in its place cannot therefore physically mitigate the loss of harbour, which will remain as a very substantial residual impact.

 

 


Table 14.7 :  Residual Landscape Impacts from CRIII (Schedule 3 Project)

Landscape Character Zone (1-17)

 

Source of Impact

Type of Impact

Magnitude of Change at Main Project Stages

Landscape Sensitivity

Residual Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Residual Impact Characteristic during Operation Phase after Implementation of Mitigation Measures

 

 

 

Construction

Operation

 

 

 

The Servicemen’s Guides Association (1)

Reclamation & Redevelopment

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

Citic Tower (2)

Redevelopment of Adjacent Areas

C

High

High

Moderate

Substantial to Moderate Negative

Substantial to Moderate Positive

Lung Wui Road (3)

Reclamation  Redevelopment

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

Tim Mei Avenue and Tim Wa Avenue (4)

Redevelopment of Adjacent Areas

C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

Formar Tamar Basin (5)

Redevelopment

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

Connaught Road Central/ Harcourt Road (6)

Redevelopment of Adjacent Areas

C

Moderate

Moderate

Low

Slight to Very Slight Negative

Slight to Very Slight Positive

Heliport (7)  (to be relocated prior to the completion of reclamation)

Reclamation Redevelopment

R,C

High

N/A

Low

Moderate to Slight Negative

N/A

Temporary Park (adjacent to Central Barracks (8) (to be relocated prior to the completion of reclamation)

Reclamation Redevelopment

R,C

High

N/A

Moderate

Substantial to Moderate Negative

N/A

Central Barracks  (9)

Redevelopment of Adjacent Areas

C

Moderate

Moderate

Moderate

Moderate to Slight Negative

Moderate to Slight Positive

Queen’s Pier/ Edinburgh Place (10) (to be relocated prior to the completion of reclamation)

Reclamation Redevelopment

R,C

High

N/A

Low

Moderate to Slight Negative

N/A

City Hall (11)

Partial  Redevelopment

R,C

High

High

Moderate

Substantial to Moderate Negative

Substantial to Moderate Positive

Northern Areas of Statue Square adjacent to Connaught Rd (12)

Redevelopment

R,C

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial Positive

“Star” Ferry Car Park (13)

Reclamation & Redevelopment

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

"Star" Ferry Pier (14) (to be relocated prior to the completion of reclamation)

Reclamation & Redevelopment

R,C

High

N/A

Moderate

Substantial to Moderate Negative

N/A

General Post Office (15)

Reclamation & Redevelopment

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

Eastern Edge of Central Reclamation Phase I (16)

Reclamation & Redevelopment of Adjacent Areas

R,C

High

High

Low

Moderate to Slight Negative

Moderate to Slight Positive

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Reclamation & Redevelopment

R

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial Negative

18Ha of Victoria Harbour between Central Reclamation Phase I and the Hong Kong Convention and Exhibition Centre (17)

Reclamation and Redevelopment

C

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial Positive

Key :    Type of  Impact                                                      =          R – Impact on Landscape Resources

                                                                                        =          C – Impact on Landscape Character

            Magnitude of Impact                                               =          None, Low, Moderate or High

            Landscape Sensitivity                                            =          Low, Medium or High

            Impact Characteristic                                             =          Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative) 

 

 

 


14.5                                  Visual Impact Assessment

14.5.1                            Introduction

This Visual Impact Assessment is concerned with visual impacts attributable to the 4no. individual Schedule 2 Projects in addition to the Schedule 3 Project.  Readers of this Visual Impact Assessment should familiarise themselves with the Baseline Study – Description of the Environment within the CRIII Works Area – presented in Appendix T.  Comparative layout plans and completion dates for each designated project are indicated in Figure 14.18. 

It should be noted that, unlike existing reclamation areas in Western Kowloon and Hung Hom, the CRIII reclamation upon completion will not remain undeveloped for a great length of time.  Upon completion of the reclamation activities construction will begin as soon as practicable on the remaining designated projects.  Similarly, upon completion of major infrastructure, construction will begin on developments upon the reclamation such as the new Central Government Offices, Festival Market and Groundscraper.  In this respect CRIII can be likened to CRI at the outlying islands ferry piers to the west.

An assessment of visual impacts attributable to the overall development, as a Schedule 3 project, is thereafter presented in para 14.5.6.

A separate Visual Impact Assessment for the ventilation shafts which will be constructed as part of the Hong Kong Station Extended Overrun Tunnel construction is included as Appendix V.  Direct reference to these structures is therefore not included in this section.

14.5.2                            Designated Project I (DP1) – Reclamation

14.5.2.1            Introduction

The construction and operation stage visual impact assessment for reclamation will include assessment of impacts attributable to the reclamation seawalls, cooling water pumping stations, ferry piers, public landing steps and other marine facilities as all these items form an integral part of the “reclamation”.  A layout plan and cross section for Designated  Project 1 is indicated in the previous Figure 14.9.

14.5.2.2            Zone of Visual Influence for Reclamation

The Zone of Visual Influence (ZVI) is the zone within which a development can be viewed without obstruction.  The edge of the ZVI is termed the Visual Envelope.  A Baseline Visual Envelope and photo viewpoint locations is indicated in the previous Figure 14.2.  It is calculated that the reclamation will be clearly visible within a zone that encompasses the southern tip of Tsim Sha Tsui to the north and Hong Kong Park to the south.  The reclamation will be clearly visible within an area of Victoria Harbour approximately 2km wide from a centreline drawn between the Tamar site in Admiralty and the Cultural Centre in Tsim Sha Tsui.

It should be noted that the ZVI is approximate and that views of the reclamation are likely to be available from additional locations.  This assessment is concerned with likely visual impacts to key visually sensitive receivers (ZVIs) within the primary ZVI.  Long distance views of the reclamation are likely to be possible from more distant locations such as elevated land and developments between Victoria Peak and Mount Cameron but it is considered that impacts upon VSRs in these locations will be of a much slighter magnitude.

14.5.2.3            Key Visually Sensitive Receivers (VSRs) for Reclamation

14.5.2.3.1 Direct views of the study area will be available from VSRs in the following locations which are indicated on Figure 14.19 and included in Table 14.8: 

·                Development within the study area - Citic Tower and Central Barracks;

·                development to the east of the study area including the Grand Hyatt Hotel and the Hong Kong Convention and Exhibition Centre;

·                development to the south of the study area including Connaught Road  Central/Harcourt Road and Queensway Road corridors;

·                development to the west of the study area including Exchange Square, One International Finance Centre and the proposed No. 2 IFC;

·                development located on the southern tip of the Kowloon Peninsula including the Regent Hotel, Sheraton Hotel, New World Centre and Star House.

·                promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre and HK Museum of Art at Tsim Sha Tsui waterfront;

·                Star Ferries travelling to/from Central to Tsim Sha Tsui;

·                Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui; and

·                additional marine traffic within Victoria Harbour including pleasure craft.

14.5.2.4            Sources of Visual Impact for Reclamation – Construction Stage

The sources of construction stage visual impacts attributable to the reclamation will include:

·                the physical process of reclaiming 18ha of new land in the harbour through importing fill material by barge;

·                the construction of temporary and permanent sea walls and drainage channels;

·                the construction of cooling water pumping stations;

·                demolition of existing Queen’s Pier and “Star” Ferry Piers;

·                the construction of reprovisioned “Star” ferry piers and public landing steps.  These structures will comprise 2no. piers per development with the “star” ferry piers located at the end of the Statue Square Open Space Corridor and the Public Landing Steps located at the end of the Historic Corridor. Neither development is indicated in figures within this Chapter due to their layout being unconfirmed at the time of study;

·                temporary site areas for storage, plant, cabins and associated site equipment; and

·                construction traffic;

·                temporary site access areas, site cabins and heavy machinery; and

·                after dark lighting and welding.

14.5.2.5            Sources of Visual Impact for Reclamation –Operation Stage

The sources of operation stage visual impacts attributable to the reclamation will include:

·                18ha of new land in the harbour;

·                permanent sea walls;

·                cooling water pumping stations; and

·                “Star” ferry piers and public landing steps.

14.5.2.6            Visual Mitigation Measures for Reclamation – Construction Stage

14.5.2.6.1                Construction stage visual mitigation measures should include:

·                sensitively designed site hoarding to help screen views to the demolition works of existing Queen’s Pier and “Star” Ferry Piers;

·                sensitively designed site hoarding to help screen views to the construction of new Public Landing Steps and “Star” Ferry Piers;

·                sensitively designed site hoarding to help screen views to the reclamation works and construction of new sea walls and drainage channels;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation;

·                advanced planting of trees and shrubs where practicable;

·                hydroseeding with perennial flower mix to areas of land which become unused for long periods during the construction period; and

·                operational time restrictions to limit after-dark welding and lighting.

14.5.2.7            Visual Mitigation Measures for Reclamation – Operation Stage

14.5.2.7.1                Operation stage visual mitigation measures should include:

·                sensitive contemporary form and finishes to new “Star” Ferry Piers and Public Landing Steps;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation where practicable and not implemented during the Construction Stage;

·                removal of all debris from reclamation and maintaining that surfaces are even; and

·                hydroseeding of reclamation, as appropriate, at formed sites awaiting development or areas likely to be unused for a long period.  These areas would be subject to ongoing irrigation and maintenance to ensure that vegetation cover is complete.   For land pending for development / construction for more than nine months, hydroseeding should include a mixture of perennial flowers.

14.5.2.8            Prediction and Evaluation of Visual Impacts For Reclamation

Residual visual impacts (i.e. impacts which remain after mitigation measures have been implemented) at construction and operation stages for reclamation are indicated in Table 14.8.


Table 14.8 : Residual Visual Impacts from Designated Project 1 - Reclamation

Location of Key Visually Sensitive Receivers (VSRs)

 

Type of VSR/ ID no. (Refer to Figure 14.19)

 

Primary Source of Impact

Min. Distance between VSR and DP1

Magnitude of Change

Receiver Sensitivity

Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Impact Characteristic during Operation Phase

After Implementation of Mitigation Measures

Primary VSRs (Development)

 

 

 

Construction

Operation

 

 

 

Hong Kong Convention and Exhibition Centre

GI/C/1

Reclamation

250m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Grand Hyatt Hotel

H/2

Reclamation

300m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Wan Chai Tower

G/IC/3

Reclamation

400m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Revenue Tower

G/IC/4

Reclamation

350m

Low

Negligible

Low

Very Slight to Negligible Negative

Negligible

Shui On Centre

C/5

Reclamation

300m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Telecom House

Hong Kong Arts Centre

Harbour View International House

C &

G/IC/6

Reclamation

280m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Fleet House

Harcourt House

C/7

Reclamation

320m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Chung Nam Building

 

C/8

Reclamation

400m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Asian House

 

C/9

Reclamation

450m

Low

Negligible

Low

Very Slight to Negligible Negative

Negligible

Hong Kong Police Force Headquarters

G/IC/10

Reclamation

380m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Citic Tower

C/11

Reclamation

130m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Paget House

 

C/12

Reclamation

550m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Marriott Hotel

H/13

Reclamation

500m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Conrad Hotel

H/14

Reclamation

600m

Low

Negligible

High

Moderate to Slight Negative

Negligible

One Pacific Place

C/15

Reclamation

500m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Two Pacific Place/Island Shangri-La Hotel

C/H/16

Reclamation

580m

Low

Negligible

Medium

Slight to very Slight Negative

Negligible

United Centre

C/17

Reclamation

400m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Queensway Government Offices

G/IC/18

Reclamation

500m

Low

Negligible

Low

Very Slight to Negligible Negative

Negligible

The Supreme Court

G/IC/19

Reclamation

460m

Low

Negligible

Low

Very Slight to Negligible Negative

Negligible

Admiralty Centre

C/20

Reclamation

350m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Far East Finance Centre

C/21

Reclamation

280m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Lippo Centre

C/22

Reclamation

340m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Citibank Plaza

 

C/23

Reclamation

480m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Bank of China Tower

C/24

Reclamation

420m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Fairmont House

 

C/25

Reclamation

340m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Bank of America Tower

C/26

Reclamation

220m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Hutchison House

C/27

Reclamation

180m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Cheung Kong Centre

 

C/28

Reclamation

420m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

PLA Forces Hong Kong Building

G/IC/29

Reclamation

70m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Furama Hotel

H/31

Reclamation, Demolition*

180m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Ritz Carlton Hotel

H/32

Reclamation, Demolition

180m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Hong Kong Club Building

C/33

Reclamation, Demolition

180m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Old Bank of China Building

C/34

Reclamation, Demolition

360m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Hong Kong and Shanghai Bank

C/35

Reclamation, Demolition

340m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Standard Chartered Bank

C/36

Reclamation, Demolition

350m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Prince’s Building

C/37

Reclamation, Demolition

280m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Mandarin Hotel

H/38

Reclamation, Demolition

200m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

St George’s Building

C/39

Reclamation, Demolition

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Swire House

C/40

Reclamation, Demolition

240m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Jardine House

C/41

Reclamation, Demolition

120m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

World Wide House

C/42

Reclamation, Demolition

230m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Exchange Square I and II

C/43

Reclamation, Demolition

60m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Positive

Exchange Square III

C/44

Reclamation, Demolition

260m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

One International Finance Centre

C/45

Reclamation, Demolition

280m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Mega Tower (approved proposal)

C/46

N/A

60m

N/A

N/A

Medium

N/A

N/A

City Hall and Garden

G/IC47

Reclamation, Demoltion

40m

High

Moderate

High

Very Substantial to Substantial Negative

Substantial to Moderte Negative

Primary VSRs – Transport Corridors

Expo Drive

T1

Reclamation

250m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Convention Avenue

T2

Reclamation

250m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Fenwick Pier Street

T3

Reclamation

140m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Fenwick Pier Street flyover and pedestrian footbridge

T4

Reclamation

200m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Lung Wui Road

T5

Reclamation

30m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Tim Mei Avenue

T6

Reclamation

50m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Tim Wa Avenue

T7

Reclamation

50m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Connaught Road/ Harcourt Road

T8

Reclamation

160m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Edinburgh Place

 

T9

Reclamation, Demolition

40m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Connaught Place

 

T10

Reclamation, Demolition

80m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

New Ferry Piers access road and pedestrian promenade (Man Yiu Street)

T11

Reclamation, Demolition

20m

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Primary VSRs – Harbour/Open Space

Harcourt Garden

O1

Reclamation

360m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Statue Square

O2

Reclamation, Demolition

150m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Victoria Harbour

M1

Reclamation, Demolition

0M

High

Moderate

High

Very Substantial to Substantial Negative

Substantial to Moderate Negative

Secondary VSRs and Kowloon Peninsula

TST promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre, and HK Museum of Art

 

Reclamation

2KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Regent Hotel, Sheraton Hotel, New World Centre, and Star House

 

Reclamation

2KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Star Ferries travelling to/from Central to Tsim Sha Tsui

 

M1

Reclamation

0-2KM

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Positive

Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui

M1

Reclamation

1-2KM

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Additional marine traffic within Victoria Harbour including pleasure craft

M1

Reclamation

0-2KM

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Positive

Victoria Peak/Mount Austin Road

R/2

Reclamation

3.5KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Negative

The Peak Tower

C/3

Reclamation

3KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Negative

Mount Gough

R/4

Reclamation

1.7KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Negative

Magazine Gap Road

R/5

Reclamation

1.5KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Negative

Robinson Road/ Bowen Road corridor

R/6

Reclamation

1KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Negative

Hopewell Centre

C/7

Reclamation

0.7KM

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Hong Kong Park

O/8

Reclamation

0.3KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Negative

Key :       Magnitude of Impact                                                                           =                 Negligible, Low, Moderate or High

                Receiver Sensitivity                                                                            =                 Low, Medium or High

                Impact Significance Thresholds                                                         =                 Negligible, Very Slight, Moderate, Substantial or Very Substantial (Positive or Negative)

                Types of Key Visually Sensitive Receivers (VSRs)                          =                 R – Residential

                                                                                                                                              T – Transport Related

                                                                                                                                              C – Commercial

                                                                                                                                              O – Open Space

                                                                                                                                              M – Marine Traffice

                                                                                                                                              G/IC – Government, Institution, Community

 

*              Demolition refers to the resumption of Queen’s Pier and “Star” Ferry Piers

 


14.5.2.9            Conclusion and Recommendations

There follows conclusions and recommendations for landscape and visual impacts associated with reclamation (Designated Project 1)

Landscape Impacts

Residual landscape impacts for reclamation are indicated in Table 14.3.  18ha of reclamation will be implemented in areas of existing harbour resource, which is considered highly sensitive to change.  The landscape character of surrounding areas is often associated with its proximity to the harbour edge. Generally, however, the study area comprises a series of unrelated architectural elements fragmented with numerous physically prominent utility features and temporary civil works.  Little or no coherence is derived from the surrounding urban environment nor is advantage taken of the few positive aspects of the site.

As a result of the baseline landscape conditions, the landscape sensitivity is lower in some character zones than might otherwise be expected.  This in turn has lowered the magnitude of impact associated with reclamation upon some character zones.  The assessment has concluded that in general the residual operation stage landscape impacts will range from moderate to very slight.  However, in the following area residual operation stage landscape impacts are likely to be very substantial to moderate:

·                Victoria Harbour.

Visual Impacts

Residual visual impacts for reclamation are indicated in Table 14.8.  The sensitivity of VSRs to the reclamation is generally reduced by the poorly articulated waterfront.  Whilst construction stage impacts are considered to be generally high, the operation stage impacts are substantially reduced by mitigation measures such as hyroseeding.  In this way many more distant VSRs will perceive their views of the study area to have changed by the addition of a green edge to the harbour.

In this context, residual operation stage visual impact characteristics are predicted to be generally moderate to negligible (negative).   The highest visual impacts, considered substantial to moderate in this assessment, will be felt by VSRs in the following locations:

·                City Hall and garden; and

·                Victoria Harbour.

Conclusion

It is considered that residual landscape and visual impacts attributable to Designated Project 1 are acceptable with mitigation measures as described in category (c) of Annex 10 of the Technical Memorandum Environmental Impact Assessment Process.  There will be some adverse effects, but these can be eliminated, reduced or offset to a large extent by specific measures.

14.5.3                            Designated Project 2 (DP2) – Primary and District Distributor Roads

14.5.3.1            Introduction

The visual impact assessment for primary and district distributor roads will include assessment of impacts attributable to the roads, drainage, utilities and other services associated with the road reserves.  A layout plan and cross section for Designated Project 2 is indicated in the previous Figure 14.10.  Proposed typical streetscape sections are indicated in the previous Figure 14.17.

Visual impacts associated with this project at both the construction and operation stage will be assessed within the context of the existing reclamation and the likely scenario that surrounding areas will be temporarily hydroseeded or under use as construction sites. Thus the magnitude of change to existing views will be lower.  This may serve to reduce the magnitude of the impacts attributable to the roads.

Zones of Visual Influence for Primary & District Distributor Roads

14.5.3.1.1 Zones of Visual Influence (ZVIs) for the Schedule 3 project as a whole are indicated in the previous Figure 14.2.  The Primary and Distributor Roads which form Designated Project 2 will be located at grade in areas of reclamation and will connect to infrastructure at the following locations:

·                Fenwick Pier Street;

·                Tim Mei Avenue;

·                Tim Wa Avenue;

·                Man Yiu Street; and

·                Outlying Islands Ferry Piers (4-7).

Key Visually Sensitive Receivers (VSRs) for Primary & District Distributor Roads

14.5.3.1.2 Key VSRs for the Schedule 3 Project as a whole are indicated in the previous Figure 14.19.  It is considered that VSRs in the following locations will be most sensitive to the construction and operation of the Primary and Distributor Roads:

·                Exchange Square I and II;

·                Man Yiu Street;

·                Jardine House;

·                Citic Tower;

·                PLA Forces Hong Kong Building;

·                Fenwick Pier Street;

·                Lung Wui Avenue;

·                Tim Mei Avenue;

·                Tim Wa Avenue;

·                Edinburgh Place; and

·                Victoria Harbour.

14.5.3.2            Sources of Visual Impact for Primary & District Distributor Roads – Construction Stage

The sources of construction stage visual impacts attributable to the Primary and District Distributor Roads will include:

·                temporary site areas for storage, plant, cabins and associated site equipment;

·                construction traffic;

·                temporary site access areas, site cabins and heavy machinery; and

·                after dark lighting and welding.

14.5.3.3            Sources of Visual Impact for Primary & District Distributor Roads – Operation Stage

The sources of operation stage visual impacts attributable to the Primary and District Distributor Roads will include:

·                the physical presence of an road system on the reclamation;

·                after dark street lighting;

·                vehicular traffic; and

·                tree and shrub planting to road corridor.

14.5.3.4            Visual Mitigation Measures for Primary and District Distributor Roads – Construction Stage

14.5.3.4.1                Construction stage visual mitigation measures should include:

·                sensitively designed site hoarding to help screen views to the road construction works;

·                designated service corridors beneath footpaths to prevent potential impacts upon vegetation during services maintenance;

·                advanced planting of trees and shrubs where practicable; and

·                operational time restrictions to limit after-dark welding and lighting.

14.5.3.5            Visual Mitigation Measures for Primary and District Distributor Roads – Operation Stage

14.5.3.5.1                Operation stage visual mitigation measures should include:

·                tree and shrub planting to all road corridors.  The vegetation matrix should adopt robust themes repeated throughout the reclamation development to reinforce the international  image of CRIII;

·                where practical, implementation of a road design hierarchy illustrated by streetscape sections in the previous Figure 14.21. Where the width of footpath permits continuous amenity planting strips should be provided;

·                sensitively designed colour themes to footpath paving areas; and

·                sensitively design of road structures and light fittings.

14.5.3.6            Prediction and Evaluation of Visual Impacts For Primary and District Distributor Roads

Residual visual impacts (i.e. impacts which remain after mitigation measures have been implemented) at construction and operation stages for Primary and District Distributor Roads are indicated in Table 14.9.

 


Table 14.9 :  Residual Visual Impacts from Designated Project 2 – Primary and District Distributor Roads

 Location of Key Visually Sensitive Receivers (VSRs)

 

Type of VSR/ ID no. (Refer to Figure 14.19)

 

Primary Source of Impact

Min. Distance between VSR and DP2

Magnitude of Change

Receiver Sensitivity

Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Impact Characteristic during Operation Phase

After Implementation of Mitigation Measures

Primary VSRs (Development)

 

 

 

Construction

Operation

 

 

 

Hong Kong Convention and Exhibition Centre

GI/C/1

Roads

350m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Grand Hyatt Hotel

H/2

Roads

350m

Low

Negligible

High

Moderate to Slight Negative

Negligible

 

Wan Chai Tower

G/IC/3

Roads

410m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Revenue Tower

G/IC/4

Roads

360m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Shui On Centre

C/5

Roads

330m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Telecom House

Hong Kong Arts Centre

Harbour View International House

C &

G/IC/6

Roads

300m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Fleet House

Harcourt House

C/7

Roads

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Chung Nam Building

C/8

Roads

300m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Asian House

C/9

Roads

320m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Hong Kong Police Force Headquarters

G/IC/10

Roads

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Citic Tower

C/11

Roads

30m

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Negative

Paget House

C/12

Roads

440m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Marriott Hotel

H/13

Roads

400m

Low

Negligible

High

Moderate to Slight Negative

Negligible

 

Conrad Hotel

H/14

Roads

450m

Low

Negligible

High

Moderate to Slight Negative

Negligible

 

One Pacific Place

C/15

Roads

360m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Two Pacific Place/Island Shangri-La Hotel

C/H/16

Roads

450m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

United Centre

C/17

Roads

250m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Queensway Government Offices

G/IC/18

Roads

420m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

The Supreme Court

G/IC/19

Roads

430m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Admiralty Centre

C/20

Roads

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Far East Finance Centre

C/21

Roads

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Lippo Centre

C/22

Roads

300m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Citibank Plaza

C/23

Roads

520m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Bank of China Tower

C/24

Roads

420m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Fairmont House

C/25

Roads

340m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Bank of America Tower

C/26

Roads

250m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Hutchison House

C/27

Roads

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Cheung Kong Centre

C/28

Roads

450m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

PLA Forces Hong Kong Building

G/IC/29

Roads

70m

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Negative

Furama Hotel

H/31

Roads

220m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Ritz Carlton Hotel

H/32

Roads

220m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Hong Kong Club Building

C/33

Roads

220m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Old Bank of China Building

C/34

Roads

410m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Hong Kong and Shanghai Bank

C/35

Roads

400m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Standard Chartered Bank

C/36

Roads

400m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Prince’s Building

C/37

Roads

300m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Mandarin Hotel

H/38

Roads

250m

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

St George’s Building

C/39

Roads

220m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Swire House

C/40

Roads

260m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Jardine House

C/41

Roads

150m

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Negative

World Wide House

C/42

Roads

270m

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

 

Exchange Square I and II

C/43

Roads

130m

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Negative

Exchange Square III

C/44

Roads

260m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

One International Finance Centre

C/45

Roads

300m

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Mega Tower (approved proposal)

C/46

Roads

40m

N/A

Low

Medium

N/A

Slight to Very Slight negative

City Hall and Garden

G/IC47

Roads

30m

High

Moderate

High

Very Substantial to Substantial Negative

Substantial to Moderate Negative

Primary VSRs – Transport Corridors

Expo Drive

T1

Roads

350m

Low

Negligible

High

Moderate to Slight  Negative

Negligible

Convention Avenue

T2

Roads

280m

Low

Negligible

High

Moderate to Slight  Negative

Negligible

Fenwick Pier Street

T3

Roads

0m

High

Low

High

Very Substantial to Substantial Negative

Moderate to Slight Negative

Fenwick Pier Street flyover and pedestrian footbridge

T4

Roads

20M

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Lung Wui Road

T5

Roads

0M

High

Low

High

Very Substantial to Substantial Negative

Moderate to Slight Negative

Tim Mei Avenue

T6

Roads

0M

High

Low

High

Very Substantial to Substantial Negative

Moderate to Slight Negative

Tim Wa Avenue

T7

Roads

0M

High

Low

High

Very Substantial to Substantial Negative

Moderate to Slight Negative

Connaught Road/ Harcourt Road

T8

Roads

200m

Low

Negligible

High

Moderate to Slight  Negative

Negligible

Edinburgh Place

 

T9

Roads

0M

High

Moderate

High

Very Substantial to Substantial Negative

Substantial to Moderate Negative

Connaught Place

 

T10

Roads

0M

Low

Negligible

High

Moderate to Slight Negative

Negligible

New Ferry Piers access road and pedestrian promenade (Man Yiu Street)

T11

Roads

0M

High

Low

High

Very Substantial to Substantial Negative

Moderate to Slight Negative

Primary VSRs – Harbour/Open Space

Harcourt Garden

O1

Roads

150m

Low

Negligible

High

Moderate to Slight Negative

Negligible

 

Statue Square

O2

Roads

200m

Low

Negligible

High

Moderate to Slight Negative

Negligible

 

Victoria Harbour

M1

Roads

120m

High

Negligible

High

Very Substantial to Substantial Negative

Negligible

Secondary VSRs and Kowloon Peninsula

TST promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre, and HK Museum of Art

 

Roads

2KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Regent Hotel, Sheraton Hotel, New World Centre, and Star House

 

Roads

2KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Star Ferries travelling to/from Central to Tsim Sha Tsui

M1

Roads

0-2KM

Moderate

Negligible

Medium

Moderate to Slight Negative

Negligible

Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui

M1

Roads

1-2KM

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Additional marine traffic within Victoria Harbour including pleasure craft

M1

Roads

0-2KM

Moderate

Negligible

Medium

Moderate to Slight Negative

Negligible

Victoria Peak/Mount Austin Road

R/2

Roads

3.5KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

The Peak Tower

C/3

Roads

3KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Mount Gough

R/4

Roads

1.7KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Magazine Gap Road

R/5

Roads

1.5KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Robinson Road/ Bowen Road corridor

R/6

Roads

1KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Hopewell Centre

C/7

Roads

0.7KM

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Hong Kong Park

O/8

Roads

0.3KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Location of Proposed Visually Sensitive Receivers  (VSRs proposed) (Refer to Figure 14.14)

 

 

 

 

 

 

 

 

Waterfront  Promenade

 OG

Roads

100m

N/A

Negligible

High

N/A

Negligible

Promenade Park

OM

Roads

30m

N/A

Low

High

N/A

Moderate to Slight Negative

Civic Plaza

OH

Roads

10m

N/A

Low

High

N/A

Moderate to Slight Negative

Historic Corridor

OD

Roads

0m

N/A

Moderate

High

N/A

Substantial to Moderate Negative

Marine Basin

OK

Roads

40m

N/A

Negligible

High

N/A

Negligible

Arts & Entertainment  Corridor

OL

Roads

15m

N/A

Low

High

N/A

Moderate to Slight Negative

Groundscraper

C

Roads

0m

N/A

Low

Medium

N/A

Slight to Very Slight Negative

Central Government Offices

G/IC

Roads

120m

N/A

Low

Medium

N/A

Slight to Very Slight Negative

Festival Market

C

Roads

10m

N/A

Low

Medium

N/A

Slight to Very Slight Negative

Statue Square Open Space Corridor

OC

Roads

0m

N/A

Negligible

High

N/A

Negligible

City Hall Memorial Garden

OE

Roads

10m

N/A

Low

High

N/A

Moderate to Slight Negative

 

Key :        Magnitude of Impact                                                           =       Negligible, Low, Moderate or High

                 Receiver Sensitivity                                                            =       Low, Medium or High

                 Impact Significance Thresholds                                         =       Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative)

                 Types of Key Visually Sensitive Receivers (VSRs           =       R – Residential

T - Transport Related

C – Commercial

O - Open Space

M - Marine Traffic

G/IC - Government, Institution, Community

 


14.5.3.7            Conclusion and Recommendations

These follow conclusions and recommendations for residual landscape and visual impacts associated with Primary and District Distributor Roads (Designated Project 2)

Landscape Impacts

Residual landscape impacts for Primary and District Distributor Roads are indicated in Table 14.4.  Construction stage impacts will be associated with the implementation of roads located within reclamation (Designated Project 1).  The landscape sensitivity of adjacent areas is lowered by its proximity to the reclamation.  Within this context, landscape impact characteristics are considered slight to very slight negative in the operation stage. 

Visual Impacts

Residual visual impacts for Primary and District Distributor Roads are indicated in Table 14.9.  The sensitivity of VSRs to the development is reduced by their proximity to the reclamation upon which the roads are located.  In this context, visual impact characteristics are considered generally moderate to negligible (negative).   The greatest visual impacts, considered substantial to moderate in this assessment, will be felt by VSRs in the following locations:

·                Edinburgh Place;

·                Historic Corridor; and

·                City Hall and garden.

Conclusion

It is considered that residual landscape and visual impacts attributable to Designated Project 2 are acceptable with mitigation measures as described in category (c) of Annex 10 of the Technical Memorandum Environmental Impact Assessment Process.  There will be some adverse effects, but these can be eliminated, reduced or offset to a large extent by specific measures.

14.5.4                            Designated Project 3 – Central-Wan Chai Bypass Tunnel

14.5.4.1            Introduction

Only the construction phase impacts for this designated project will be considered as only the construction works are entrusted to the CRIII project.  The operation phase impacts are being assessed by HyD/MWO under a separate EIA Study. A layout plan and cross section for Designated Project 3 is indicated in the previous Figure 14.11.

It should be noted that the tunnel is scheduled for completion at the same time as the reclamation.  It is predicted, therefore, that the tunnel construction works will be viewed within the context of the reclamation construction works.  Thus the magnitude of change to existing views will be lower.  This may serve to reduce the magnitude of the impacts attributable to the tunnel.

14.5.4.2            Zones of Visual Influence for the Central-Wan Chai Bypass Tunnel

Zones of Visual Influence (ZVIs) for the Schedule 3 project as a whole are indicated in the previous Figure 14.2.  The Central-Wan Chai Bypass Tunnel which forms Designated Project 3 will be located in cut and cover tunnel in areas of reclamation and will interface with existing reclamation at CRI beneath Man Yiu Street. 

14.5.4.3            Key Visually Sensitive Receivers (VSRs) for the Central-Wan Chai Bypass Tunnel

Key VSRs for the Schedule 3 project as a whole are indicated in the previous Figure 14.19.  It is considered that VSRs in the following locations will be most sensitive to the construction of the Central-Wan Chai Bypass Tunnel:

·                Citic Tower;

·                PLA Forces Hong Kong Building;

·                Lung Wui Avenue; and

·                Victoria Harbour.

14.5.4.4            Sources of Visual Impact for the Central-Wan Chai Bypass Tunnel – Construction Stage

The sources of construction stage visual impacts attributable to the Central-Wan Chai Bypass Tunnel will include:

·                temporary site areas for storage, plant, cabins and associated site equipment;

·                construction traffic;

·                temporary site access areas, site cabins and heavy machinery; and

·                after dark lighting and welding.

14.5.4.5            Visual Mitigation Measures for Central-Wan Chai Bypass Tunnel – Construction Stage

Construction stage visual mitigation measures should include:

·                sensitively designed site hoarding to help screen views to the tunnel construction works;

·                advanced planting of trees and shrubs where practicable;

·                operational time restrictions to limit after-dark welding and lighting;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation; and

·                hydroseeding to areas of land which become unused for long periiods during the construction period.

14.5.4.6            Prediction and Evaluation of Visual Impacts for Central-Wan Chai Bypass Tunnel –Construction Stage

Residual visual impacts (i.e. impacts which remain after mitigation measures have been implemented) at the construction stage for Central-Wan Chai Bypass Tunnel are indicated in Table 14.10.

 

 


Table 14.10 :  Residual Visual Impacts from Designated Project 3 – Central-Wan Chai Bypass Tunnel

Locatin of Key Visually Sensitive Receivers (VSRs)

 

Type of VSR/ ID no. (Refer to Figure 14.19)

 

Primary Source of Impact

Min. Distance between VSR and DP3

Magnitude of Change

Receiver Sensitivity

Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Impact Characteristic during Operation Phase

After Implementation of Mitigation Measures

Primary VSRs (Development)

 

 

 

Construction

Operation

 

 

 

Hong Kong Convention and Exhibition Centre

 

GI/C/1

Tunnel Construction

300m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Grand Hyatt Hotel

 

H/2

Tunnel Construction

300m

Low

N/A

High

Moderate to Slight Negative

N/A

Wan Chai Tower

 

G/IC/3

Tunnel Construction

400m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Revenue Tower

 

G/IC/4

Tunnel Construction

400m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Shui On Centre

 

C/5

Tunnel Construction

330m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Telecom House

Hong Kong Arts Centre

Harbour View International House

C &

G/IC/6

Tunnel Construction

300m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Fleet House

Harcourt House

C/7

Tunnel Construction

380m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Chung Nam Building

 

C/8

Tunnel Construction

420m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Asian House

 

C/9

Tunnel Construction

500m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hong Kong Police Force Headquarters

 

G/IC/10

Tunnel Construction

400m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Citic Tower

C/11

Tunnel Construction

220m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Paget House

 

C/12

Tunnel Construction

650m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Marriott Hotel

H/13

Tunnel Construction

580m

Low

N/A

High

Moderate to Slight Negative

N/A

Conrad Hotel

 

H/14

Tunnel Construction

670m

Low

N/A

High

Moderate to Slight Negative

N/A

One Pacific Place

 

C/15

Tunnel Construction

580m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Two Pacific Place/Island Shangri-La Hotel

C/H/16

Tunnel Construction

650m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

United Centre

 

C/17

Tunnel Construction

480m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Queensway Government Offices

 

G/IC/18

Tunnel Construction

600m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

The Supreme Court

 

G/IC/19

Tunnel Construction

550m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Admiralty Centre

 

C/20

Tunnel Construction

420m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Far East Finance Centre

 

C/21

Tunnel Construction

360m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Lippo Centre

 

C/22

Tunnel Construction

460m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Citibank Plaza

C/23

Tunnel Construction

680m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Bank of China Tower

C/24

Tunnel Construction

550m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Fairmont House

C/25

Tunnel Construction

460m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Bank of America Tower

C/26

Tunnel Construction

340m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hutchison House

C/27

Tunnel Construction

330m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Cheung Kong Centre

C/28

Tunnel Construction

570m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

PLA Forces Hong Kong Building

G/IC/29

Tunnel Construction

160m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Furama Hotel

H/31

Tunnel Construction

320m

Moderate

N/A

High

Substantial to Moderate Negative

N/A

Ritz Carlton Hotel

H/32

Tunnel Construction

320m

Moderate

N/A

High

Substantial to Moderate Negative

N/A

Hong Kong Club Building

C/33

Tunnel Construction

320m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Old Bank of China Building

C/34

Tunnel Construction

530m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hong Kong and Shanghai Bank

C/35

Tunnel Construction

550m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Standard Chartered Bank

C/36

Tunnel Construction

570m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Prince’s Building

C/37

Tunnel Construction

480m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Mandarin Hotel

H/38

Tunnel Construction

400m

Moderate

N/A

High

Substantial to Moderate Negative

N/A

St George’s Building

C/39

Tunnel Construction

410m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Swire House

C/40

Tunnel Construction

430m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Jardine House

C/41

Tunnel Construction

320m

High

N/A

Medium

Substantial to Moderate Negative

N/A

World Wide House

C/42

Tunnel Construction

450m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Exchange Square I and II

C/43

Tunnel Construction

300m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Exchange Square III

C/44

Tunnel Construction

340m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

One International Finance Centre

C/45

Tunnel Construction

360m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Mega Tower (approved proposal)

C/46

Tunnel Construction

100m

N/A

N/A

Medium

N/A

N/A

City Hall and Garden

G/IC47

Tunnel Construction

200m

Moderate

N/A

High

Substantial to Moderate Negative

N/A

Primary VSRs- Transport Corridors

Expo Drive

T1

Tunnel Construction

250m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Convention Avenue

T2

Tunnel Construction

250m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Fenwick Pier Street

T3

Tunnel Construction

220m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Fenwick Pier Street flyover and pedestrian footbridge

T4

Tunnel Construction

330m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Lung Wui Road

T5

Tunnel Construction

140m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Tim Mei Avenue

T6

Tunnel Construction

140m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Tim Wa Avenue

T7

Tunnel Construction

140m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Connaught Road/ Harcourt Road

T8

Tunnel Construction

300m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Edinburgh Place

 

T9

Tunnel Construction

220m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Connaught Place

 

T10

Tunnel Construction

250m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

New Ferry Piers access road and pedestrian promenade (Man Yiu Street)

T11

Tunnel Construction

40m

High

N/A

Medium

Substantial to Moderate Negative

N/A

 

Harcourt Garden

O1

Tunnel Construction

430m

Low

 N/A

High

Moderate to Slight Negative

N/A

Statue Square

O2

Tunnel Construction

360m

Low

N/A

High

Moderate to Slight Negative

N/A

Victoria Harbour

M1

Tunnel Construction

30m

High

N/A

High

Very Substantial to Substantical

N/A

Secondary VSRs and Kowloon Peninsula

TST promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre, and HK Museum of Art

 

Tunnel Construction

2KM

Low

N/A

High

Moderate to Slight Negative

N/A

Regent Hotel, Sheraton Hotel, New World Centre, and Star House

 

Tunnel Construction

2KM

Low

N/A

High

Moderate to Slight Negative

N/A

Star Ferries travelling to/from Central to Tsim Sha Tsui

M1

Tunnel Construction

0-2KM

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui

M1

Tunnel Construction

1-2KM

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Additional marine traffic within Victoria Harbour including pleasure craft

M1

Tunnel Construction

0-2KM

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Victoria Peak/Mount Austin Road

R/2

Tunnel Construction

3.5KM

Low

N/A

High

Moderate to Slight Negative

N/A

The Peak Tower

C/3

Tunnel Construction

3KM

Low

N/A

High

Moderate to Slight Negative

N/A

Mount Gough

R/4

Tunnel Construction

1.7KM

Low

N/A

High

Moderate to Slight Negative

N/A

Magazine Gap Road

R/5

Tunnel Construction

1.5KM

Low

N/A

High

Moderate to Slight Negative

N/A

Robinson Road/ Bowen Road corridor

R/6

Tunnel Construction

1KM

Low

N/A

High

Moderate to Slight Negative

N/A

Hopewell Centre

C/7

Tunnel Construction

0.7KM

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hong Kong Park

O/8

Tunnel Construction

0.3KM

Low

N/A

High

Moderate to Slight Negative

N/A

Key :        Magnitude of Impact                                                           =       Negligible, Low, Moderate or High

                 Receiver Sensitivity                                                            =       Low, Medium or High

                 Impact Significance Thresholds                                         =       Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative)

                 Types of Key Visually Sensitive Receivers (VSRs           =       R – Residential

T - Transport Related

C – Commercial

O - Open Space

M - Marine Traffic

G/IC - Government, Institution, Community

 

 


14.5.4.7            Conclusion and Recommendations

These follow conclusions and recommendations for residual landscape and visual impacts associated with the Central-Wan Chai Bypass Tunnel (Designated Project 3):

Landscape Impacts

Residual landscape impacts for Central Wan Chai Bypass Tunnel are indicated in Table 14.5.  Construction stage impacts will be associated with the implementation of a cut and cover tunnel located within partially or wholly completed reclamation (Designated Project 1).  The landscape sensitivity of adjacent areas is lowered by its proximity to the reclamation works.  Within this context, landscape impact characteristics are considered moderate to slight negative in the construction stage. 

The operation stage landscape impact assessment of the Central Wan Chai Bypass Tunnel is not undertaken by this study.  The project proponent for the Central-Wan Chai Bypass Project has, however, advised that no above ground structures will be needed for the project within the CRIII Study Area.  Operation Stage landscape impacts are therefore considered to be negligible.

Visual Impacts

Residual visual impacts for Central Wan Chai Bypass Tunnel are indicated in Table 14.10.  The sensitivity of VSRs to the development is reduced by their proximity to the reclamation works within which the tunnel is located.  In this context, visual impact characteristics are considered generally moderate to very slight negative.   There will, however, be VSRs who are deemed more sensitive due to their close proximity to the construction works and the unobstructed views to the development which this affords.  Higher construction stage impacts, of a substantial to moderate negative nature, will be associated with VSRs in the following locations:

·                PLA Forces Hong Kong Building;

·                Edinburgh Place;

·                Mandarin Hotel;

·                City Hall and garden;

·                Citic Tower;

·                Lung Wui Road;

·                Victoria Harbour; and

·                Man Yiu Street.

The operation stage visual impact assessment of the Central Wan Chai Bypass Tunnel is not undertaken by this study. The project proponent for the Central-Wan Chai Bypass Project has, however, advised that no above ground structures will be needed for the project within the CRIII Study Area.  Operation Stage visual impacts are therefore considered to be negligible.

Conclusion

In concluding the assessment of landscape and visual impacts for the Central-Wan Chai Bypass Tunnel, it is necessary to balance the findings of the construction stage impact assessment with the knowledge that, during the operation stage as advised by the project proponent for the project, no landscape and visual impacts within the CRIII area will be associated with this development.  It is considered, therefore, that residual landscape and visual impacts attributable to Designated Project 3 are acceptable with mitigation measures as described in category (c) of Annex 10 of the Technical Memorandum Environmental Impact Assessment Process.  There will be some adverse effects, but these can be eliminated, reduced or offset to a large extent by specific measures.

14.5.5                            Designated Project 4 – North Island Line Protection Works within CRIII

14.5.5.1            Introduction

Only the construction phase impacts for this designated project will be considered as only the construction works are entrusted to the CRIII project.  The operation phase impacts for the protection works are assessed as insignificant as the works are totally below ground.  These impacts for the NIL are being undertaken by MTRC under a separate EIA Study. A  layout plan and cross section for Designated Project 4 is indicated in the previous Figure 14.12. 

It should be noted that the works are scheduled for completion just after the reclamation.  It is predicted, therefore, that the construction works will be viewed within the context of the reclamation construction works.  Thus the magnitude of change to existing views will be lower.  This may serve to reduce the magnitude of the impacts attributable to the protection works.

14.5.5.2            Zones of Visual Influence for North Island Line Protection Works within CRIII

14.5.5.2.1                Zones of Visual Influence (ZVIs) for the Schedule 3 project as a whole are indicated in the previous Figure 14.2.  The North Island Line Protection Works within CRIII which forms Designated Project 4 will be located in the advance station structural envelope works cut and cover tunnel areas of reclamation and will interface with existing reclamation at CRII to the north of Tamar. 

14.5.5.3            Key Visually Sensitive Receivers (VSRs) for North Island Line Protection Works within CRIII

Key VSRs for the Schedule 3 project as a whole are indicated in the previous Figure 14.19.  It is considered that VSRs in the following locations will be most sensitive to the construction of the North Island Line Protection Works within CRIII:

·                Citic Tower;

·                PLA Forces Hong Kong Building;

·                Lung Wui Avenue; and

·                Victoria Harbour.

14.5.5.4            Sources of Visual Impact for the North Island Line Protection Works within CRIII – Construction Stage

The sources of construction stage visual impacts attributable to the North Island Line Protection Works within CRIII will include:

·                temporary site areas for storage, plant, cabins and associated site equipment;

·                construction traffic;

·                temporary site access areas, site cabins and heavy machinery; and

·                after dark lighting and welding.

14.5.5.5            Visual Mitigation Measures for the North Island Line Protection Works with CRIII – Construction Stage

Visual mitigation measures should include:

·                sensitively designed site hoarding to help screen views to the tunnel construction works;

·                advanced planting of trees and shrubs where practicable;

·                operational time restrictions to limit after-dark welding and lighting;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation; and

·                hydroseeding to areas of land which become unused for long periods during the construction period.

14.5.5.6            Prediction and Evaluation of Visual Impacts for the North Island Line Protection Works with CRIII –Construction Stage

Residual visual impacts (i.e. impacts which remain after mitigation measures have been implemented) at the construction stage for North Island Line Protection Works within CRIII are indicated in Table 14.11.

 

 


Table 14.11 :  Residual Visual Impacts from Designated Project 4 - North Island Line Protection Works within CRIII

Location of Key Visually Sensitive Receivers (VSRs)

 

Type of VSR/ ID no. (Refer to Figure 14.19)

 

Primary Source of Impact

Min. Distance between VSR and Study Area

Magnitude of Change

Receiver Sensitivity

Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Impact Characteristic during Operation Phase

After Implementation of Mitigation Measures

Primary VSRs (Development)

 

 

 

Construction

Operation

 

 

 

Hong Kong Convention and Exhibition Centre

GI/C/1

Railway Station Structural Envelope  & Tunnel Construction

380m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Grand Hyatt Hotel

 

H/2

Railway Station Structural Envelope  & Tunnel Construction

380m

Low

N/A

High

Moderate to Slight Negative

N/A

Wan Chai Tower

 

G/IC/3

Railway Station Structural Envelope  & Tunnel Construction

430m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Revenue Tower

 

G/IC/4

Railway Station Structural Envelope  & Tunnel Construction

400m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Shui On Centre

 

C/5

Railway Station Structural Envelope  & Tunnel Construction

350m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Telecom House

Hong Kong Arts Centre

Harbour View International House

C &

G/IC/6

Railway Station Structural Envelope  & Tunnel Construction

330m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Fleet House

Harcourt House

C/7

Railway Station Structural Envelope  & Tunnel Construction

360m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Chung Nam Building

 

C/8

Railway Station Structural Envelope  & Tunnel Construction

400m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Asian House

 

C/9

Railway Station Structural Envelope  & Tunnel Construction

420m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hong Kong Police Force Headquarters

 

G/IC/10

Railway Station Structural Envelope  & Tunnel Construction

350m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Citic Tower

C/11

Railway Station Structural Envelope  & Tunnel Construction

190m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Paget House

 

C/12

Railway Station Structural Envelope  & Tunnel Construction

580m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Marriott Hotel

 

H/13

Railway Station Structural Envelope  & Tunnel Construction

560m

Low

N/A

High

Moderate to Slight Negative

N/A

Conrad Hotel

 

H/14

Railway Station Structural Envelope  & Tunnel Construction

650m

Low

N/A

High

Moderate to Slight Negative

N/A

One Pacific Place

 

C/15

Railway Station Structural Envelope  & Tunnel Construction

550m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Two Pacific Place/Island Shangri-La Hotel

C/H/16

Railway Station Structural Envelope  & Tunnel Construction

630m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

United Centre

 

C/17

Railway Station Structural Envelope  & Tunnel Construction

450m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Queensway Government Offices

 

G/IC/18

Railway Station Structural Envelope  & Tunnel Construction

580m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

The Supreme Court

 

G/IC/19

Railway Station Structural Envelope  & Tunnel Construction

500m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Admiralty Centre

 

C/20

Railway Station Structural Envelope  & Tunnel Construction

350m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Far East Finance Centre

 

C/21

Railway Station Structural Envelope  & Tunnel Construction

300m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Lippo Centre

 

C/22

Railway Station Structural Envelope  & Tunnel Construction

370m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Citibank Plaza

 

C/23

Railway Station Structural Envelope  & Tunnel Construction

650m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Bank of China Tower

 

C/24

Railway Station Structural Envelope  & Tunnel Construction

500m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Fairmont House

 

C/25

Railway Station Structural Envelope  & Tunnel Construction

380m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Bank of America Tower

 

C/26

Railway Station Structural Envelope  & Tunnel Construction

270m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hutchison House

C/27

Railway Station Structural Envelope  & Tunnel Construction

280m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Cheung Kong Centre

C/28

Railway Station Structural Envelope  & Tunnel Construction

570m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

PLA Forces Hong Kong Building

 

G/IC/29

Railway Station Structural Envelope  & Tunnel Construction

90m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Furama Hotel

H/31

Railway Station Structural Envelope  & Tunnel Construction

260m

Moderate

N/A

High

Substantial to Moderate Negative

N/A

Ritz Carlton Hotel

 

H/32

Railway Station Structural Envelope  & Tunnel Construction

300m

Low

N/A

High

Moderate to Slight Negative

N/A

Hong Kong Club Building

 

C/33

Railway Station Structural Envelope  & Tunnel Construction

350m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Old Bank of China Building

 

C/34

Railway Station Structural Envelope  & Tunnel Construction

550m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hong Kong and Shanghai Bank

 

C/35

Railway Station Structural Envelope  & Tunnel Construction

580m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Standard Chartered Bank

 

C/36

Railway Station Structural Envelope  & Tunnel Construction

610m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Prince’s Building

 

C/37

Railway Station Structural Envelope  & Tunnel Construction

550m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Mandarin Hotel

H/38

Railway Station Structural Envelope  & Tunnel Construction

500m

Low

N/A

High

Moderate to Slight Negative

N/A

St George’s Building

 

C/39

Railway Station Structural Envelope  & Tunnel Construction

560m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Swire House

 

C/40

Railway Station Structural Envelope  & Tunnel Construction

600m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Jardine House

 

C/41

Railway Station Structural Envelope  & Tunnel Construction

520m

Low

N/A

Medium

 Slight to Very Slight Negative

N/A

World Wide House

 

C/42

Railway Station Structural Envelope  & Tunnel Construction

700m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Exchange Square I and II

C/43

Railway Station Structural Envelope  & Tunnel Construction

600m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Exchange Square III

 

C/44

Railway Station Structural Envelope  & Tunnel Construction

750m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

One International Finance Centre

C/45

Railway Station Structural Envelope  & Tunnel Construction

800m

Low

N/A

Medium

Slight to Very Slight Negative

 

N/A

Mega Tower (approved proposal)

C/46

Railway Station Structural Envelope  & Tunnel Construction

580m

N/A

N/A

Medium

N/A

N/A

City Hall and Garden

G/ IC47

Railway Station Structural Envelope  & Tunnel Construction

200m

 moderate

 N/A

 high

Substantial to Moderate Negative

N/A

Primary VSRs – Transport Corridors

Expo Drive

T1

Railway Station Structural Envelope  & Tunnel Construction

300m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Convention Avenue

T2

Railway Station Structural Envelope  & Tunnel Construction

300m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Fenwick Pier Street

T3

Railway Station Structural Envelope  & Tunnel Construction

150m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Fenwick Pier Street flyover and pedestrian footbridge

T4

Railway Station Structural Envelope  & Tunnel Construction

240m

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Lung Wui Road

T5

Railway Station Structural Envelope  & Tunnel Construction

0m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Tim Mei Avenue

T6

Railway Station Structural Envelope  & Tunnel Construction

0m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Tim Wa Avenue

T7

Railway Station Structural Envelope  & Tunnel Construction

0m

High

N/A

Medium

Substantial to Moderate Negative

N/A

Connaught Road/ Harcourt Road

T8

Railway Station Structural Envelope  & Tunnel Construction

170m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Edinburgh Place

 

T9

Railway Station Structural Envelope  & Tunnel Construction

200m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Connaught Place

 

T10

Railway Station Structural Envelope  & Tunnel Construction

500m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

New Ferry Piers access road and pedestrian promenade (Man Yiu Street)

T11

Railway Station Structural Envelope  & Tunnel Construction

560m

Low

N/A

Medium

Slight to Very Slight Negative

N/A

 

Harcourt Garden

 

O1

Railway Station Structural Envelope  & Tunnel Construction

350m

Low

N/A

High

Moderate to Slight Negative

N/A

Statue Square

 

O2

Railway Station Structural Envelope  & Tunnel Construction

460m

Low

N/A

High

Moderate to Slight Negative

N/A

Victoria Harbour

M1

Railway Station Structural Envelope  & Tunnel Construction

120m

High

N/A

High

Very Substantial to Substantial Negative

N/A

Secondary VSRs and Kowloon Peninsula

TST promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre, and HK Museum of Art

 

Railway Station Structural Envelope  & Tunnel Construction

2KM

Low

N/A

High

Moderate to Slight Negative

N/A

Regent Hotel, Sheraton Hotel, New World Centre, and Star House

 

Railway Station Structural Envelope  & Tunnel Construction

2KM

Low

N/A

High

Moderate to Slight Negative

N/A

Star Ferries travelling to/from Central to Tsim Sha Tsui

M1

Railway Station Structural Envelope  & Tunnel Construction

0-2KM

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui

M1

Railway Station Structural Envelope  & Tunnel Construction

1-2KM

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Additional marine traffic within Victoria Harbour including pleasure craft

M1

Railway Station Structural Envelope  & Tunnel Construction

0-2KM

Moderate

N/A

Medium

Moderate to Slight Negative

N/A

Victoria Peak/Mount Austin Road

 

R/2

Railway Station Structural Envelope  & Tunnel Construction

3.5KM

Low

N/A

High

Moderate to Slight Negative

N/A

The Peak Tower

 

C/3

Railway Station Structural Envelope  & Tunnel Construction

3KM

Low

N/A

High

Moderate to Slight Negative

N/A

Mount Gough

 

R/4

Railway Station Structural Envelope  & Tunnel Construction

1.7KM

Low

N/A

High

Moderate to Slight Negative

N/A

Magazine Gap Road

 

R/5

Railway Station Structural Envelope  & Tunnel Construction

1.5KM

Low

N/A

High

Moderate to Slight Negative

N/A

Robinson Road/ Bowen Road corridor

 

R/6

Railway Station Structural Envelope  & Tunnel Construction

1KM

Low

N/A

High

Moderate to Slight Negative

N/A

Hopewell Centre

C/7

Railway Station Structural Envelope  & Tunnel Construction

0.7KM

Low

N/A

Medium

Slight to Very Slight Negative

N/A

Hong Kong Park

O/8

Railway Station Structural Envelope  & Tunnel Construction

0.3KM

Low

N/A

High

Moderate to Slight Negative

N/A

Key :        Magnitude of Impact                                                           =       Negligible, Low, Moderate or High

                 Receiver Sensitivity                                                            =       Low, Medium or High

                 Impact Significance Thresholds                                         =       Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative)

                 Types of Key Visually Sensitive Receivers (VSRs           =       R – Residential

T - Transport Related

C – Commercial

O - Open Space

M - Marine Traffic

G/IC - Government, Institution, Community

 

 

 


14.5.5.7            Conclusion and  Recommendations

These follow conclusions and recommendations for residual landscape and visual impacts associated with the North Island Line Protection Works within CRIII  (Designated Project 4):

Landscape Impacts

Residual landscape impacts from the North Island Line Protection Works within CRIII are indicated in Table 14.6.  Construction stage impacts will be associated with the implementation of the advanced station structural envelope works and the cut and cover tunnel located within partially or wholly completed reclamation (Designated Project 1).  The landscape sensitivity of adjacent areas is lowered by its proximity to the reclamation works.  Within this context, landscape impact characteristics are considered moderate to slight negative in the construction stage. 

Although the operation stage landscape impact assessment of the North Island Line Protection Works within CRIII is not undertaken by this study, the impacts are considered insignificant as the NIL works are situated totally below ground.

Visual Impacts

Residual visual impacts from the North Island Line Protection Works within CRIII are indicated in Table 14.11.  The sensitivity of VSRs to the development is reduced by their proximity to the reclamation works within which the works are located.  In this context, visual impact characteristics are considered generally moderate to very slight negative.   There will, however, be VSRs who are deemed more sensitive due to their close proximity to the construction works and the unobstructed views to the development which this affords.  Higher construction stage impacts, of a substantial to moderate negative nature, will be associated with VSRs in the following locations:

·                Furama Hotel;

·                City Hall and garden;

·                Citic Tower;

·                Tim Wa Avenue;

·                Lung Wui Road;

·                Tim Mei Avenue; and

·                Victoria Harbour.

Although the operation stage visual impact assessment of the North Island Line Protection Works within CRIII is currently being undertaken by MTRC, the impacts are considered insignificant as the NIL works are situated totally below ground.

Conclusion

In concluding the assessment of landscape and visual impacts for the North Island Line Protection Works within CRIII, it is necessary to balance the findings of this construction stage landscape and visual impact assessment with the operation stage assessment being undertaken by MTRC.  The latter assessment is presently unavailable, however, as indicated above, for both the landscape and visual impacts, the effects of the NIL protection works on the surrounding areas are considered insignificant as the tunnel works are located below ground level.

14.5.6                            Schedule 3 Project – Engineering Feasibility Study for CRIII and Future Development on CRIII Site

14.5.6.1            Introduction

14.5.6.1.1                The Visual Impact Study seeks to address potential visual impacts which may be caused by CRIII as a Schedule 3 Project.  Sources of impact will be based upon the reclamation and construction programme and subsequently upon the design and disposition of the development itself.  In reviewing the visual impacts upon existing baseline character zones, the following assumptions have been made:

·                building heights are stepped to preserve a 20% building-free area to protect the Victoria Peak ridgeline as recommended in the Metroplan;

·                maximum building heights will decrease from the inland towards the waterfront in a north-south alignment;

·                building height contours will decrease from a maximum 180mPD at the former Tamar Basin to 8mPD (plant rooms, etc.) for waterfront development;

·                a maximum building height at 30mPD will be maintained at sites flanking the northern section of the open space corridors;

·                a stepped east-west height principle will achieve a distinctive profile allowing flexibility for an interesting built form;

·                comprehensive urban design parameters will be adopted to achieve a visually coherent palette of paving materials, colours, street furniture, signage and planting; and

·                generally, any new development will contain finishes and fixtures of a higher quality than exist in the current environment.

14.5.6.2            Zones of Visual Influence

14.5.6.2.1                The Zones of Visual Influence (ZVIs) are indicated on the previous Figure 14.2.  Primary Visually Sensitive Receivers (VSRs), the proposed CRIII layout and development heights are indicated on the previous Figure 14.19.  The VSRs indicated are not intended to be exhaustive and it is likely that some adjacent developments will also view the study area.  Distant views of the study area will be possible from the following locations which are indicated on the previous Figure 14.2:

·                Tsim Sha Tsui Cultural Centre / Star Ferry Pier;

·                Victoria Peak;

·                The Peak Tower;

·                Mount Gough;

·                Magazine Gap Road; and

·                Robinson Road/ Bowen Road.

14.5.6.3            Key Visually Sensitive Receivers (VSRs)

14.5.6.3.1 Direct views of the study area will be available from VSRs in the following locations which are indicated on the previous Figure 14.19 and included in Table 14.12:

·                development within the study area - Citic Tower and Central Barracks;

·                development to the east of the study area including the Grand Hyatt Hotel and the Hong Kong Convention and Exhibition Centre;

·                development to the south of the study area including Connaught Road  Central/Harcourt Road and Queensway Road corridors;

·                development to the west of the study area including Exchange Square, One International Finance Centre and the proposed No. 2 IFC;

·                development located on the southern tip of the Kowloon Peninsula including the Regent Hotel, Sheraton Hotel, New World Centre and Star House.

·                promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre and HK Museum of Art at Tsim Sha Tsui waterfront;

·                Star Ferries travelling to/from Central to Tsim Sha Tsui;

·                Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui; and

·                additional marine traffic within Victoria Harbour including pleasure craft.

14.5.6.4            Sources of Visual Impact

14.5.6.4.1                The primary source of visual impacts will be loss of views to Victoria Harbour caused by the new development.  Table 14.12 provides a review of the likely magnitude of construction and operational stage visual impacts upon Primary and Secondary VSRs.  The previous Figure 14.19 indicates the layout and building heights of the proposed development.

Construction Stage

14.5.6.4.2                                                                                                                                                                                                                                         The sources of visual impacts during the construction stage will include the following:

·                the physical process of site clearance and demolition of key developments, namely City Hall (High Block only), General Post Office, Star Ferry Pier and Queens Pier,

·                the construction works of principal infrastructure development, namely reclamation, Primary, Distributor and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and the North Island Line Protection Works within CRIII;

·                the construction works of key developments, namely CDA Groundscraper, Festival Market, Central Government Complex, parks, plazas, marine basin, and open space corridors.

·                construction traffic;

·                temporary site access areas, site cabins and heavy machinery;

·                construction site traffic on the reclamation; and

·                after dark lighting and welding.

Operational Stage

14.5.6.4.3 The sources of visual impacts during the operational stage will include the following:

·                the proposed reclamation itself;

·                new transport infrastructure;

·                new low, medium and high-rise development; and

·                extensive landscaped pedestrian spaces.

14.5.6.5            Prediction and Evaluation of Visual Impacts

Construction Stage

14.5.6.5.1 Visual impacts during the Construction Stage are assessed in Table 14.12 and will include the following:

·                views of site clearance and demolition of key developments, namely City Hall (High Block only), General Post Office, Star Ferry Pier and Queens Pier,

·                views of the construction works of principal infrastructure development, namely reclamation, Primary, Distributor and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and the North Island Line Protection Works within CRIII;

·                the construction works of key developments, namely CDA Groundscraper, Festival Market, Central Government Complex, parks, plazas, marine basin, and open space corridors.

·                views of barges carrying fill, floating cranes and dredging equipment;

·                loss of views to Victoria Harbour from VSRs located to the east, south and west of the study area;

·                loss of visual relationship between Central-Wan Chai waterfront and Victoria Harbour;

·                views of reclamation activity including pipe, cable, sewer and drainage works;

·                visual glare from welding and site illumination;

·                rotational site traffic, deliveries and cranes;

·                scaffolding and emergent structures; and

·                increased heavy vehicular traffic within the Central-Wan Chai Districts.

14.5.6.5.2 It is considered that VSRs located within developments close to the construction works will receive the most substantial negative visual impacts.  On this basis, VSRs in the following developments would be worst affected during the CRIII construction programme, initially by reclamation works and, subsequently, by the demolition and construction of major developments:

·                Jardine House – demolition of General Post Office and construction of Groundscraper (50mPD);

·                Exchange Square I and II - demolition of General Post Office and construction of Groundscraper (50mPD);

·                Furama Hotel – demolition of City Hall and construction of replacement development (50mPD);

·                Ritz Carlton Hotel – demolition of City Hall and construction of replacement development (50mPD);

·                Hong Kong Club  – demolition of City Hall and construction of replacement development (50mPD);

·                PLA Forces Hong Kong Building – reclamation and Festival Market (25mPD);

·                Far East Finance Centre – construction of Central Government Offices (180mPD);

·                Admiralty Centre – construction of Central Government Complex (CGC) (180mPD);

·                Citic Tower – reclamation and construction of CGC, Red Cross Headquarters Development and additional development to the north (80-180mPD);

·                Hong Kong Police Force, May House – construction of CGC and additional development (80-180mPD);

·                Telecom House, Hong Kong Arts Centre, Harbour View International House – reclamation and construction of waterside development (15-25mPD);

·                Grand Hyatt Hotel – reclamation and construction of waterside development (15-25mPD); and

·                Hong Kong Convention and Exhibition Centre (HKCEC) – reclamation and construction of waterside development (15-25mPD).

14.5.6.5.3 Additionally there will be negative visual impacts, of a lesser magnitude, associated with the construction of the Statue Square Open Space Corridor and the Historic Corridor, which would run in parallel.  These impacts will be primarily associated with tree felling, road works, traffic management schemes, resurfacing and replanting operations.  VSRs receiving the greatest visual impacts from the construction of open space corridors are likely to be located in the following developments:

·                Mandarin Oriental Hotel;

·                Hong Kong and Shanghai Bank;

·                Legislative Council Building; and

·                Hong Kong Club Building.

14.5.6.5.4 Substantial negative visual impacts will be felt by VSRs, especially pedestrians, located at street level.  The following streets will be located adjacent to major construction works and will face varying degrees of disruption, which will be associated with substantial negative visual impacts:

·                Harcourt Road;

·                Tim Mei Avenue;

·                Tim Wa Avenue;

·                Lung Wui Road;

·                Edinburgh Place;

·                Connaught Place;

·                Man Yiu Street;

·                Chater Road; and

·                Jackson Road.

14.5.6.5.5 Slight to moderate negative visual impacts will be felt by VSRs located in the following locations in Tsim Sha Tsui and Victoria Harbour:

·                development located on the southern tip of the Kowloon Peninsula including the Regent Hotel, Sheraton Hotel, New World Centre and Star House.

·                promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre and HK Museum of Art at Tsim Sha Tsui waterfront;

·                Star Ferries travelling to/from Central to Tsim Sha Tsui;

·                Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui; and

·                additional marine traffic within Victoria Harbour including pleasure craft.

Operational Stage

14.5.6.5.6 Visual impacts during the Operational Stage are indicated in Table 14.12. Proposed development layout and building heights are indicated in the previous Figure 14.19.  Existing VSRs illustrated in relation to proposed development are also indicated in Figure 14.19.  Primary visual impacts will be loss of views to Victoria Harbour.  However, due to the nature of the CRIII proposals, there are expected to be many positive visual impacts associated with the development.  Visual impacts, both negative and positive, are assessed in Table 14.12 and will include the following:

·                loss of or obstruction of views of Victoria Harbour from north and east facing VSRs within lower 16 floors of Jardine House and Exchange Square I and II due to 50mPD height ‘Groundscraper’ development.  Existing general post office height is 15mPD. Views of the Harbour will therefore be lost to an additional 12 floors of VSRs in Jardine House and Exchange Square I and II, resulting in negative visual impacts;

·                loss of or obstruction to views of Victoria Harbour from north facing VSRs within lower 13 floors of the Hong Kong Club Building, Ritz Carlton Hotel and Furama Hotel due to 50mPD height redevelopment of the City Hall.  Existing City Hall height is 12mPD (39mPD tower is located north of Cenotaph).  Views of the Harbour will therefore be lost to an additional 8 floors of VSRs in the Hong Kong Club, Ritz Carlton Hotel and Furama Hotel, resulting in negative visual impacts;

·                loss of or obstruction to views of Victoria Harbour from north facing VSRs within all floors of Far East Finance Centre and Admiralty Centre Towers I and II due to the 180mPD high Central Government Complex, resulting in negative visual impacts.  Existing views are unobstructed by the undeveloped Tamar site.  Some VSRs will retain views to Victoria Harbour subject to the proposed CGC layout design;

·                loss of views to Victoria Harbour from north facing VSRs within all floors of lower residential blocks of Central Barracks (e.g. Blake Block and Amethyst Block) due to 25mPD height Festival Market development, resulting in negative visual impacts.  Views are currently unobstructed.  Views of Victoria Harbour from VSRs within the main Prince of Wales Building will be unobstructed and positive visual impacts will be associated with the new Waterfront Promenade and Civic Plaza;

·                loss of or obstruction to views of Victoria Harbour from north facing VSRs within lower 20 floors of Citic Tower due to 80mPD height development to the north, resulting in negative visual impacts.  Views to Victoria Harbour are currently unobstructed;

·                loss of or obstruction to views of Victoria Harbour from north west facing VSRs within all floors of  Hong Kong Police Headquarters at May House due to 80-130mPD height development to the east, resulting in negative visual impacts.  Views north from the Police HQ will remain largely unchanged, though improvements will be associated with the landscape treatment to the Waterfront Promenade and Marine Basin, resulting in positive visual impacts (subject to the final Wanchai Development Phase II project); and

·                improved quality of views over the proposed Marine Basin and Waterfront Promenade from north facing VSRs within all floors of the  Grand Hyatt Hotel, Shui On Centre, Telecom House, Hong Kong Arts Centre, and Harbour View International House, resulting in positive visual impacts.  Low level development along the new waterfront is not expected to obstruct Harbour views from these developments.

14.5.6.5.7                Additionally there will be positive visual impacts associated with the Statue Square Open Space Corridor and the Historic Corridor, which would run in parallel.  These impacts will be primarily associated with avenue tree planting, upgraded streetscape and landscape, pedestrian plazas, and use of high quality materials and finishes.  VSRs benefiting from the greatest visual impacts are likely to be located in the following developments:

·                Mandarin Oriental Hotel;

·                Hong Kong and Shanghai Bank;

·                Legislative Council Building; and

·                Hong Kong Club Building.

14.5.6.5.8 Substantial positive visual impacts will be felt by VSRs, especially pedestrians, located at street level.  The following streets will be located adjacent to, or within, improved streetscape and will be associated with substantial positive visual impacts:

·                Harcourt Road;

·                Tim Mei Avenue;

·                Tim Wa Avenue;

·                Lung Wui Road;

·                Edinburgh Place;

·                Connaught Place;

·                Man Yiu Street; and

·                Chater Road;

14.5.6.5.9 Negligible to moderate positive impacts will be felt by VSRs located in the following locations in Tsim Sha Tsui and Victoria Harbour:

·                development located on the southern tip of the Kowloon Peninsula including the Regent Hotel, Sheraton Hotel, New World Centre and Star House.

·                promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre and HK Museum of Art at Tsim Sha Tsui waterfront;

·                Star Ferries travelling to/from Central to Tsim Sha Tsui;

·                Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui; and

·                additional marine traffic within Victoria Harbour including pleasure craft.

14.5.6.6            Visual Mitigation Measures

Construction Stage

14.5.6.6.1 Construction stage visual mitigation measures should include:

·                sensitively designed site hoarding to help screen views to the construction works of principal infrastructure development, namely reclamation, Primary, Distributor and District Distributor Roads, the Central-Wan Chai Bypass Tunnel, the Hong Kong Station Overrun Tunnel and the North Island Line Protection Works within CRIII;

·                temporary screen planting of shrubs and trees on mounded land to the periphery of the reclamation where practicable; and

·                operational time restrictions to limit after-dark welding and lighting.

Operational Stage

14.5.6.6.2 Operational stage visual mitigation measures should include:

·                building heights will be stepped where practicable to preserve a 20% building-free backdrop to protect the Victoria Peak ridgeline as recommended in the Metroplan (refer to Figure 14.20);

·                maximum building heights will decrease from the inland towards the waterfront in a north-south alignment (refer to Figure 14.20);

·                building height contours will decrease from a maximum 180mPD at the former Tamar Basin to 8mPD (plant rooms, etc.) for waterfront development ensuring that the proposed CGC development does not compromise the Peak Ridgeline Guidelines(refer to Figure 14.20);

·                a maximum building height at 30mPD will be maintained at sites flanking the northern section of the open space corridors(refer to Figure 14.20);

·                a stepped east-west height principle will achieve a wave-like profile allowing flexibility for an interesting built form;

·                comprehensive urban design parameters will be adopted to achieve a visually coherent palette of paving materials, colours, street furniture, signage and planting;

·                generally, any new development will contain finishes and fixtures of a higher quality than exist in the current environment;

·                implementation of the Waterfront Promenade, Statue Square Corridor, Historic Corridor, Civic Corridor, Arts and Entertainment Corridor (under WDII), Streetscape Network, Landscape Decks, and Supplementary Landscape Spaces.  These are illustrated through the photomontages presented as Figure 14.21 - 14.27.

·                provision of a legible, integrated pedestrian circulation system linking major activity nodes, reinforcing links with adjoining areas, and providing an international quality hard and soft landscape treatment;

·                provision of an integrated network of local and regional open spaces for passive and active recreation;

·                overall enhancement of the visual amenity and character of Victoria Harbour;

·                preservation of selected architectural features, such as the “Star” Ferry Pier clock;

·                preservation of existing significant vegetation, principally the two Banyan Trees flanking the Tamar Site;

·                ensuring that the City Hall Complex and Memorial Garden maintain a visual ‘presence’ in the landscape framework;

·                semi-mature avenue tree planting to road boundaries and planting to elevated structures;

·                an international quality of hard and soft landscape finishes;

·                sensitive design and profile of the seawall to minimise visual impacts associated with the reclamation; and

·                international quality of site furniture including lighting, seating, litter bins and balustrades, which adhere to an overall CRIII development palette.

14.5.6.7            Residual Visual Impacts

14.5.6.7.1 A residual visual impact is defined as the impact remaining after all practical methods of mitigation have been implemented.  Residual visual impacts are indicated in Table 14.12 and will include the following:

·                loss of or obstruction to views of Victoria Harbour from north and east facing VSRs within lower 16 floors of Jardine House and Exchange Square I and II due to 65mPD height ‘Groundscraper’ development.

·                loss of or obstruction to views of Victoria Harbour from north facing VSRs within lower 13 floors of the Hong Kong Club Building, Ritz Carlton Hotel and Furama Hotel due to 50mPD height redevelopment of City Hall.

·                loss of or obstruction to views of Victoria Harbour from north facing VSRs within all floors of Far East Finance Centre and Admiralty Centre Towers I and II due to 180mPD height CGC development;

·                loss of views to Victoria Harbour from north facing VSRs within all floors of lower residential blocks of Central Barracks (e.g. Blake Block and Amethyst Block) due to 25mPD height Festival Market development;

·                loss of or obstruction to views of Victoria Harbour from north facing VSRs within lower 20 floors of Citic Tower due to 80mPD height development to the north;

·                loss of or obstruction to views of Victoria Harbour from north west facing VSRs within all floors of  Hong Kong Police Headquarters at May House due to 80-130mPD height development to the east;

·                improved quality of views over the proposed Marine Basin and Waterfront Promenade from north facing VSRs within all floors of the  Grand Hyatt Hotel, Shui On Centre, Telecom House, Hong Kong Arts Centre, and Harbour View International House, resulting in positive visual impacts.  Low level development along the new waterfront is not expected to obstruct Harbour views from these developments.

14.5.6.7.2                Additionally there will be positive visual impacts associated with the Statue Square Open Space Corridor and the Historic Corridor, which would run in parallel.  These impacts will be primarily associated with avenue tree planting, upgraded streetscape and landscape, pedestrian plazas, and use of high quality materials and finishes.  VSRs benefiting from the greatest visual impacts (very substantial to substantial) are likely to be located in the following developments:

·                Mandarin Oriental Hotel;

·                Grand Hyatt Hotel;

·                Statue Square; and

·                Victoria Harbour.

14.5.6.7.3                Substantial to moderate positive visual impacts will be felt (but not limited to) pedestrians, located at street level.  The following streets will be located adjacent to, or within, improved streetscape and will be associated with substantial positive visual impacts:

·                Harcourt Road;

·                Tim Mei Avenue;

·                Tim Wa Avenue;

·                Lung Wui Road;

·                Edinburgh Place;

·                Connaught Place;

·                Man Yiu Street; and

·                Chater Road;

14.5.6.7.4                Moderate to negligible positive impacts will be felt by (but not limited to) VSRs located in the following locations in Tsim Sha Tsui and Victoria Harbour:

·                development located on the southern tip of the Kowloon Peninsula including the Regent Hotel, Sheraton Hotel, New World Centre and Star House.

·                promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre and HK Museum of Art at Tsim Sha Tsui waterfront;

·                Star Ferries travelling to/from Central to Tsim Sha Tsui;

·                Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui; and

·                Additional marine traffic within Victoria Harbour including pleasure craft.


Table 14.12 : Residual Visual Impacts from CRIII (Schedule 3 Project)

Key Visually Sensitive Receivers (VSRs)

 

Type of VSR/ ID no. (Refer to Figure 14.19)

 

Primary Source of Impact

Min. Distance between VSR and Study Area

Magnitude of Change

Receiver Sensitivity

Impact Characteristic during Construction Phase after Implementation of Mitigation Measures

Impact Characteristic during Operation Phase

After Implementation of Mitigation Measures

Primary VSRs (Development)

 

 

 

Construction

Operation

 

 

 

Hong Kong Convention and Exhibition Centre

GI/C/1

Reclamation, Proposed Development

30M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Grand Hyatt Hotel

H/2

Reclamation, Proposed Development

80M

Moderate

High

High

Substantial to Moderate Negative

Very Substantial to Substantial Positive

Wan Chai Tower

G/IC/3

Proposed Development

180M

Moderate

High

Medium

Moderate to Slight Negative

Substantial to Moderate Positive

Revenue Tower

G/IC/4

Proposed Development

210M

Moderate

High

Medium

Moderate to Slight Negative

Substantial to Moderate Positive

Shui On Centre

C/5

Proposed Development

150M

Moderate

High

Medium

Moderate to Slight Negative

Substantial to Moderate Positive

Telecom House

Hong Kong Arts Centre

Harbour View International House

C &

G/IC/6

Proposed Development

150M

Moderate

High

Medium

Moderate to Slight Negative

Substantial to Moderate Positive

Fleet House

Harcourt House

C/7

Proposed Development

180M

Moderate

Moderate

Medium

Moderate to Slight Negative

Moderate to Slight Positive

Chung Nam Building

C/8

Proposed Development

230M

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Asian House

C/9

Proposed Development

280M

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Hong Kong Police Force Headquarters

G/IC/10

Proposed Development

80M

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Citic Tower

C/11

Reclamation, Proposed Development

0M

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Negative

Paget House

C/12

Proposed Development

260M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Marriott Hotel

H/13

Proposed Development

210M

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

Conrad Hotel

H/14

Proposed Development

300M

Moderate

Low

High

Substantial to Moderate Negative

Moderate to Slight Negative

One Pacific Place

C/15

Proposed Development

180M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Two Pacific Place/Island Shangri-La Hotel

C/H/16

Proposed Development

260M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

United Centre

C/17

Proposed Development

90M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Queensway Government Offices

G/IC/18

Proposed Development

220M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

The Supreme Court

G/IC/19

Proposed Development

220M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Admiralty Centre

C/20

Reclamation, Proposed Development

30M

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Far East Finance Centre

C/21

Reclamation, Proposed Development

30M

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Negative

Lippo Centre

C/22

Proposed Development

120M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Citibank Plaza

C/23

Proposed Development

330M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Bank of China Tower

C/24

Proposed Development

230M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Fairmont House

C/25

Proposed Development

120M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Negative

Bank of America Tower

C/26

Reclamation, Proposed Development

20M

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Positive

Hutchison House

C/27

Reclamation, Proposed Development

20M

High

Low

Medium

Substantial to Moderate Negative

Slight to Very Slight Positive

Cheung Kong Centre

C/28

Proposed Development

250M

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Positive

PLA Forces Hong Kong Building

G/IC/29

Reclamation, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Furama Hotel

H/31

City Hall Demolition, Proposed Development

20M

High

Low

High

Very Substantial to Substantial Negative

Moderate to Slight Positive

Ritz Carlton Hotel

H/32

City Hall Demolition, Proposed Development

20M

High

Moderate

High

Very Substantial to Substantial Negative

Substantial to Moderate Positive

Hong Kong Club Building

C/33

City Hall Demolition, Proposed Development

20M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Bank of China Building

C/34

Proposed Development

180M

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Hong Kong and Shanghai Bank

C/35

Proposed Development

160M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Standard Chartered Bank

C/36

Proposed Development

170M

Moderate

Moderate

Medium

Moderate to Slight Negative

Moderate to Slight Positive

Prince’s Building

C/37

Proposed Development

60M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Mandarin Hotel

H/38

Proposed Development

20M

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial Positive

St George’s Building

C/39

Proposed Development

70M

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Swire House

C/40

Proposed Development

140M

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Jardine House

C/41

Post Office Demolition, Proposed Development

30M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

World Wide House

C/42

Proposed Development

150M

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Exchange Square I and II

C/43

Post Office Demolition, Proposed Development

20M

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Positive

Exchange Square III

C/44

Proposed Development

180M

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Positive

One International Finance Centre

C/45

Post Office Demolition, Proposed Development

250M

High

Moderate

Medium

Substantial to Moderate Negative

Moderate to Slight Positive

Mega Tower (approved proposal)

C/46

Proposed Development

20M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Primary VSRs – Transport Corridors

Expo Drive

T1

Reclamation

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Convention Avenue

T2

Reclamation

10M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Fenwick Pier Street

T3

Reclamation

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Fenwick Pier Street flyover and pedestrian footbridge

T4

Reclamation, Proposed Development

20M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Lung Wui Road

T5

Reclamation, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Tim Mei Avenue

T6

Reclamation, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Tim Wa Avenue

T7

Reclamation, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Connaught Road/ Harcourt Road

T8

Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Edinburgh Place

 

T9

City Hall Demolition, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Connaught Place

 

T10

Post Office Demolition, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

New Ferry Piers access road and pedestrian promenade

T11

Reclamation, Proposed Development

0M

High

High

Medium

Substantial to Moderate Negative

Substantial to Moderate Positive

Primary VSRs – Harbour/Open Space

Harcourt Garden

O1

Proposed Development

30M

Medium

Moderate

High

Substantial to Moderate Negative

Moderate to Slight Positive

Statue Square

O2

Proposed Development

0M

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial Positive

Victoria Harbour

M1

Reclamation, Proposed Development

0M

High

High

High

Very Substantial to Substantial Negative

Very Substantial to Substantial Positive

Secondary VSRs and Kowloon Peninsula

TST promenade areas adjacent to clock tower, Star Ferry Pier, HK Cultural Centre, and HK Museum of Art

 

Reclamation, Proposed Development

2KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Regent Hotel, Sheraton Hotel, New World Centre, and Star House

 

Reclamation, Proposed Development

2KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Star Ferries travelling to/from Central to Tsim Sha Tsui

M1

Reclamation, Proposed Development

0-2KM

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Positive

Star Ferries travelling to/from Wan Chai to Tsim Sha Tsui

M1

Reclamation, Proposed Development

1-2KM

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Additional marine traffic within Victoria Harbour including pleasure craft

M1

Reclamation, Proposed Development

0-2KM

Moderate

Low

Medium

Moderate to Slight Negative

Slight to Very Slight Positive

Victoria Peak/Mount Austin Road

R/2

Proposed Development

3.5KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

The Peak Tower

C/3

Proposed Development

3KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Mount Gough

R/4

Proposed Development

1.7KM

Low

Negligible

High

Moderate to Slight Negative

Negligible

Magazine Gap Road

R/5

Proposed Development

1.5KM

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Robinson Road/ Bowen Road corridor

R/6

Proposed Development

1KM

Low

Negligible

Medium

Slight to Very Slight Negative

Negligible

Hopewell Centre

C/7

Proposed Development

0.7KM

Low

Low

Medium

Slight to Very Slight Negative

Slight to Very Slight Positive

Hong Kong Park

O/8

Proposed Development

0.3KM

Low

Low

High

Moderate to Slight Negative

Moderate to Slight Positive

Key :        Magnitude of Impact                                                           =       Negligible, Low, Moderate or High

                 Receiver Sensitivity                                                            =       Low, Medium or High

                 Impact Significance Thresholds                                         =       Negligible, Very Slight, Slight, Moderate, Substantial or Very Substantial (Positive or Negative)

                 Types of Key Visually Sensitive Receivers (VSRs           =       R – Residential

T - Transport Related

C – Commercial

O - Open Space

M - Marine Traffic

G/IC - Government, Institution, Community

 


14.6                                  Environmental Monitoring and Audit

14.6.1                            Environmental monitoring and audit requirements are described in the stand alone EM&A Manual.

14.7                                  Implementation and Funding

14.7.1                            Implementation and Management Funding

14.7.1.1            Table 14.13 indicates the proposed network of agencies involved in the implementation, management and maintenance process of the landscape framework.

Table 14.13 :  Landscape Framework - Implementation, Management and Maintenance Agents - Schedule of Responsibilities

Landscape Element

Implementation & Funding

Management Agent

Maintenance Agent

Parks

Promenade (hard and soft landscape)

To be determined by PLB

To be determined by PLB

To be determined by PLB

DOS (hard landscape)

LCSD

LCSD

ArchSD (PSB)

DOS (soft landscape)

LCSD

LCSD

LCSD

LOS (hard landscape)

LCSD

LCSD

ArchSD (PSB)

LOS (soft landscape)

LCSD

LCSD

LCSD

Civic Square

Hard Landscape

To be determined by PLB

To be determined by PLB

To be determined by PLB

Soft Landscape

To be determined by PLB

To be determined by PLB

To be determined by PLB

Festival Market (hard and soft landscape)

Private Developer

Private Developer

Private Developer

Amenity Areas (soft landscape only)

Adjoining Roads

TDD

In accordance with WBTC 18/94

In accordance with WBTC 18/94

Seawall and Marine Structures

TDD

CED

CED

Highway Landscape within 5m of Outer Kerb: - (i.e. pavement, central medians, traffic islands, land between junctions not suitable for other use)

TDD

In accordance with WBTC 18/94

In accordance with WBTC 18/94

Notes:    Soft landscape works include – verge and amenity strip planting including grasses; central median planting; trees in paving; planting in planter beds, tubs and pots, and existing conserved vegetation.

                Maintenance by ArchSD (PSB) of general areas is subject to funding by Home Affairs Bureau (HAB).  

14.8                                  Conclusions and Recommendations

14.8.1                            Landscape Impacts

14.8.1.1            The primary landscape impact will be the loss of 18Ha of Victoria Harbour.  The provision of an international quality landscape promenade, connected to open space corridors and plazas, as part of a larger provision for District and Regional Open Space, would reduce this negative landscape impact from very substantial in the construction stage to very slight in the operational stage.  Whilst the loss of harbour will remain as a very slight residual impact, it is considered an acceptable impact without which the numerous positive landscape impacts would not be achievable.

14.8.2                            Visual Impacts

14.8.2.1            The primary visual impact will be the loss of views to Victoria Harbour from VSRs in existing developments along the southern boundary of CRIII.  The majority of visual obstruction will be caused by the new CGC development on the existing Tamar site, which will reach a 180mPD height.  Moderate negative impacts are likely to be caused to VSRs in the Admiralty Centre, Far East Finance Centre and HK Police Force HQ.  However, due to stepped building heights and the generally open and low rise nature of development, set within a landscaped open space framework, the majority of visual impacts are expected to be positive. 

14.8.3                            Conclusion

14.8.3.1            It is considered that both the landscape and visual impacts associated with CRIII development are acceptable with mitigation measures as described in category (c) of Annex 10 of the EIA-TM.   There will be some adverse effects, but these can be eliminated, reduced or offset to a large extent by specific measures.


15.                                      MONITORING & AUDIT

15.1                                  Introduction

15.1.1                            A full Environmental Monitoring and Audit (EM&A) Manual has been produced as a separate deliverable as part of the CRIII project for inclusion in contract documentation. EM&A will, therefore, only be discussed in general terms in this section. The EM&A process ensures that proactive mitigation measures are adopted to avoid the occurrence of adverse environmental impacts.

15.1.2                            Monitoring can be most concisely defined as the systematic collection of data through a series of repetitive measurements. It involves the measurement of environmental parameters before project initiation to establish a baseline against which impacts can be measured, followed by impact monitoring during project construction and the early period of operation. Environmental audit provides the verification of practice and certification of data and is the process of:

·                verifying that all selected levels of the parameters measured by the environmental monitoring programme are within the agreed limits or levels during project construction;

·                determining and recommending any necessary remedial measures, for which environmental monitoring forms the basis; and

·                organising and interpreting the environmental monitoring data to establish the record of change associated with a project.

15.1.3                            Limit Level is a reference value which indicates that deterioration in environmental quality is significant and that urgent corrective action is required.

15.1.4                            Action Level is a reference value to be used as an early warning of a deterioration in environmental quality.  Attainment of the Action Level shall stimulate the increase in frequency of monitoring and the undertaking of investigation of the cause and possibly remedial action if appropriate.

15.1.5                            The EM&A Programme will consist of a schedule of monitoring and auditing of designated environmental parameters in the vicinity of the CRIII in order:

·                to provide a baseline database of "ambient", or prevailing background conditions immediately prior to the commencement of the project.  This is normally conducted over a 2 week period prior to commencement of construction;

·                to monitor and interpret any perturbations of prevailing background conditions with respect to acceptance criteria during construction and initial operation in order to provide an early indication that any of the environmental control measures or construction practices are failing to achieve the required standards;

·                to provide data to determine the effectiveness of any mitigation or control measures implemented through changes in working practice undertaken if acceptance criteria are exceeded;

·                to provide a database of conditions after construction for the assessment of the extended effects of construction and for the post-project audit;

·                to provide an early indication if any of the environmental control measures or environmental design assumptions might fail to achieve their objectives during operation;

·                to assess compliance with contractual and legislative environmental standards;

·                to assess the validity of the action and limit levels (AL levels) set for the event/ action plans; and

·                to ensure that only acceptable environmental impacts impinge upon nearby sensitive uses and receivers with the aim of minimising adverse impact upon the surrounding environs.

15.2                                  Dust

15.2.1                            A system of dust monitoring and auditing of the reclamation development will be established to ensure that construction takes place with a minimum of adverse impact on nearby sensitive receivers and in compliance with the Air Quality Objectives for Hong Kong. Locations for monitoring should be representative of air quality conditions experienced at the identified air sensitive receivers and will be presented in the EM&A Manual.

15.2.2                            Table 15.1 details the AL Levels which should be applied to the CRIII dust monitoring programme.

Table 15.1 :  AL Levels for Total Suspended Particulate (TSP)

Parameter

24-hour Average TSP

1-hour Average TSP

Action Level

Baseline+30%

Baseline +30%

Limit Level

260 *

500 *

Note     *   Hong Kong Air Quality Objectives and Contractual Standard

15.2.3                            An analysis and summary would be completed for exceedances of AL levels. Reasons for exceedances, a description of actions taken in the event of exceedances and any follow-up procedures related to earlier non-compliance would be included. Event/action plans implemented in the event of non-compliance with the AL level would be devised in accordance with the recommendations provided by EPD.

15.3                                  Noise

15.3.1.1            A system of noise monitoring and auditing of the CRIII project may be established to ensure that construction takes place with a minimum of adverse impact on the nearby potential NSR of the HKAPA and in compliance with the Noise Control Ordinance. Construction Noise Permits may be required for some works. The monitoring location will be representative of the noise levels experienced at the NSR and will be presented in the EM&A Manual.

15.3.1.2            Noise monitoring will be undertaken before the commencement of the works to determine essential background and control data for the purposes of defining Action Levels. Additional objectives of noise monitoring and audit include the following: 

·                to collect sufficient data to ensure that predicted impacts and environmental standards are not exceeded;

·                to evaluate and report on the noise levels measured and their significance;

·                to identify any measures necessary to mitigate unacceptable effects;

·                to provide data to determine the effectiveness of any mitigation measures which may be sought through changes in working practice, plant and equipment, location of plant and equipment, acoustic screens and barriers etc.; and

·                to protect the nearby NSR from unacceptable noise impact.

15.3.2                            Indicative AL levels are shown in Table 15.2. These may be further reviewed following the baseline study.

Table 15.2 :  AL Levels for Noise Measured at NSR during Construction

Period

Weekdays

0700 to 1900 Hours
Aeq (30 min)

Evenings
1900 to 2300 Hours
Sundays and General Holidays
Aeq (5 min)

Night-time
2300 to 0700 Hours
Aeq (5 min)

Action Level

When one documented complaint is received

Limit Level

75 dB(A)

70* dB(A)

60* dB(A)

Note:  * selected based on area sensitivity rating ‘C’

15.3.3                            All data recorded in each period would be presented in both tabular and graphical format for presentation on a regular basis. An analysis and summary would be completed for exceedances of AL levels, reasons for exceedances, a description of actions taken in the event of exceedances and any follow-up procedures related to earlier non-compliance. Event/action plans implemented in the event of non-compliance with AL levels would be dictated by recommendations from EPD.


15.4                                  Water Quality

15.4.1                            A system of water quality monitoring and auditing will be established to ensure that the project causes minimum adverse impact on water quality.

15.4.2                            Monitoring locations will be based on the discharge points of the works areas, indicative locations within the Harbour, and seawater intakes, as necessary. The exact locations will be determined prior to the commencement of the works.

15.4.3                            The EM&A programme will be carried out:

·                to determine the essential environmental background water quality;

·                to collect all data necessary to monitor significant impacts;

·                to evaluate the quality and the significance of the data;

·                to identify any measures necessary to mitigate unacceptable effects;

·                to determine any extra monitoring necessary to assess the effectiveness of the mitigation measures;

·                to ensure that construction is undertaken in the most environmentally acceptable way and in such a manner as to cause as little impact as possible to the Harbour water quality;

·                to provide an early indication if any of the environmental controls, measures or environmental design assumptions might fail to achieve their objectives during operation;

·                to access compliance with the Environmental and Pollution Control Requirements; and

·                to issue reports on the above procedures on a regular basis.

15.4.4                            All data recorded for each period would be presented in tabular format for presentation on a regular basis.  An analysis of the data would be provided including a summary of exceedances of AL levels, reasons for exceedances, a description of actions taken in the event of exceedances and any follow-up procedures related to earlier non-compliance. Event/action plans implemented in the event of non-compliance with AL level would be based on the recommendations in the EPD generic EM&A Manual.

15.4.5                            The monitoring programme will involve collection of samples each week from each discharge point or Harbour monitoring location for analysis of suspended solids, turbidity, dissolved oxygen and pH.  The number and frequency of samples will be included in the EM&A Manual.

 


16.                                      SUMMARY

16.1                                  Potential Environmental Impacts and Key Issues

16.1.1.1            Water Quality and Sediment Transport Impacts and Key Issues

16.1.1.2            Key issues in terms of water quality will be those resulting from the presence of the temporary embayment in the study area during the construction phase and the dredging of the bottom sediment. This could lead to a decline in water circulation and flushing, and accumulation of thermal and pollutant discharges. Changes of particular concern include increases in temperature, BOD, SS, and nutrients present within the organic discharges, resulting decreases in DO, and the subsequent impacts upon seawater intakes which serve a number of commercially important buildings in the Central Business District of Hong Kong and the WSD flushing water intake located near the Wan Chai Public Cargo Working Area.  Modelling results, however, indicate that for all the water quality parameters simulated, there was no obvious deterioration in water quality in any local area of the proposed reclamation.  It is therefore concluded that the intermediate layout of the proposed reclamation would not result in any significant deterioration in water quality compared to present day conditions. Model results also predict that current expedient connections would not generate water quality problems in relation to the proposed reclamation.

16.1.1.3            In addition, it is considered that the unmitigated disturbance of contaminated marine sediments within the study area could lead to unacceptable impacts upon water quality.  With the implementation of the recommended mitigation measures (for example, strict dredging and handling techniques), however, the amount of contamination released from marine sediments during dredging should be minimal and not result any adverse impacts to the surrunding waters.

16.1.1.4            The placement of fill may lead to water quality impacts resulting from increases in SS, declines in DO, and impacts upon cooling water intakes in the vicinity. Modelling of dredging and filling works indicate that increases in SS levels will occur at the reclamation site.  However, mitigations measures including the use of closed clamshell grab-dredging and prohibition of stockpiling of dredged material on site are recommended.  The use of silt screens at cooling / flushing water intakes would also assist in ensuring that no disruption occurs as a result of CRIII works.

16.1.1.5            No unacceptable impacts upon water movement are anticipated as a result of the completed reclamation layout. It is considered that the new coastline will eliminate embayed and slack water areas, so reinstating the original flow experienced prior to reclamation, apart from in the area between CRIII and HKCEC Extension. A small embayment created at this area will last for some 20 months from the construction of the CRIII seawall in May 2005 until the reclamation of the adjacent area under the WDII project in January 2007.  As a mitigation measure, to avoid the accumulationof water borne pollutants within this embayment, an impermeable barrier, suspended from a floating boom on the water surface and extending down to the seabed will be erected by the CRIII Contractor on completion of the CRIII eastern seawall. The barrier will channel the stormwater discharge flows from Culvert L to the outside of the embayment.  The CRIII Contractor will maintain this barrier until the WDII Contractor takes possession of this site, where upon the WDII Contractor will takeover the maintenance of this barrier until the reclamation works in this area are carried out and the new Culvert L extension is constructed.  At the time water quality modelling works were carried out no information was available for the Wan Chai Development Phase II Project and therefore the WDII works were not considered in the CRIII assessment.  A cumulative assessment of the CRIII and WDII reclamation work has, however, been conducted by the WDII Consultant and is included in Appendix Q of the EIA Report for reference.

16.1.1.6            Additional sewage generated by the development on CRIII (approximately 489 l/s) will be collected in a local sewage gravity pipework system, directed to the CW3 Trunk Sewer and from there to the Wan Chai East screening plant for treatment.  This method of dealing with the flows has been accepted by the DSD and EPD.  DSD have confirmed that sufficient capacity is available within the CW3 Trunk Sewer to cope with the flows from CRIII.

16.1.1.7            This assessment, therefore, concludes that no insurmountable water quality impacts are anticipated during construction of the reclamation project. However, a wide range of mitigation measures and working method controls will be necessary to ensure this.

16.1.2                            Noise Pollution and Key Issues

16.1.2.1            The only potential NSR which may be affected by noise from CRIII is the outside performance area associated with the Hong Kong Academy of Performing Arts (HKAPA). Other commercial buildings, hotels, the Central Barracks and Government buildings are ventilated and do not rely on openable windows for ventilation. They are not, therefore, considered to be noise-sensitive uses. Construction phase noise mitigation measures have been recommended. EM&A of construction noise is also recommended to check the compliance of the noise criteria, and details are be presented in the EM&A Manual.

16.1.2.2            The proposed buildings on the reclamation are also likely to be centrally ventilated and are not noise-sensitive. Indicative traffic noise levels (predicted for the year 2027 by Road P2 will be a maximum of 77.7dB(A) at the Central Barracks. As these are not specifically defined as sensitive uses under the EIAO TM (ie. not domestic premises and not relying on openable windows for ventilation), additional mitigation for the road is not proposed. Noise levels at the ceremonial space and HKAPA outdoor arena are a maximum of 65.2 db(A).

16.1.2.3            Setback is recommended from the primary distributor along the landscaped recreation area to ensure that traffic noise is not intrusive to users of the promenade.

16.1.2.4            Noise will also be generated by the fixed noise sources of ventilation building and shafts for the EOT and noise from the seawater pumping stations. Noise limits for the noise sources have been recommended to ensure that the NCO noise limits are met at noise sensitive receivers. The pumping stations will be located underground and have sufficient separation from the HKAPA not to have a significant noise impact. The helicopter landing pad will be relocated away from CRIII and will not therefore impact the study area. Since there is only one potentially noise sensitive receiver in the study area, overall noise impacts are not anticipated to be significant. It is considered that no insurmountable residual impacts will arise from the post-project CRIII.

16.1.3                            Air Pollution and Key Issues

16.1.3.1            Demolition, dredging, reclamation and infrastructure construction have been identified as the major dust generating activities during the construction phase of the project. The air sensitive receivers for CRIII are the air intakes for the surrounding buildings and, potentially, the outside performance area of the HKAPA. The initial assessment has indicated that, with the implementation of recommended air pollution control measures, the dust levels can be controlled to within the statutory (260 mgm-3 24 hour average TSP) and recommended (500 mgm-3  hourly TSP) dust limits.

16.1.3.2            An asbestos survey is recommended for the structures due to be demolished to investigate the presence of any asbestos containing materials. If asbestos is found to be present, an asbestos abatement plan will be required and a registered asbestos contractor should carry out asbestos removal, if required.

16.1.3.3            The initial operational assessment of emissions from the open sections of road and portal and ventilation buildings indicates that the air quality at the ASRs is predicted to comply with the HKAQO for NO2 (as the critical air pollutant from vehicular exhaust emissions).

16.1.4                            Ecological and Land Contamination Impacts and Key Issues

16.1.4.1            There are no ecologically sensitive areas in the vicinity of CRIII. The water quality in Victoria Harbour is considered poor due to high organic loads, and is characterised by low levels of dissolved oxygen (particularly deeper in the water column) and high suspended solids and turbidity. As a result, much of the harbour is ecologically degraded and will only support pollution tolerant benthic species and fouling organisms. The impact on these organisms is not considered to be significant, given that the ecosystem is already considerably degraded. The terrestrial environment will be improved with the provision of the landscaped waterfront promenade area. Overall adverse ecological impacts will not be significant.

16.1.4.2            Since the reclamation will involve the generation of new land by the use of uncontaminated marine sands, contaminated land will not be an issue for CRIII.

16.1.5                            Solid Waste Impacts and Key Issues

16.1.5.1            Review of available sediment quality data and previously conducted sediment analyses indicates that the marine sediments in the proposed CRIII area are likely to be seriously contaminated and as such will require special disposal provisions. The dredged material will therefore not be suitable for conventional disposal at a gazetted marine disposal ground.  Consultation with the MFC will be necessary to finalise the disposal allocation of contaminated sediment.

16.1.5.2            The mitigation measures recommended in this report should be strictly followed to minimise any potential adverse impacts of the dredging works and associated sediment disposal, and to protect short term, local water quality. The Contractor will be required to conduct further detailed sediment analysis to confirm the sediment contamination level and finalise the required disposal allocation.

16.1.5.3            Provided that construction waste arisings are handled, transported and disposed of using approved methods, and that no solid or liquid wastes enter surrounding marine waters, no significant adverse environmental impacts are envisaged.  Thus, it is anticipated that no insurmountable waste management impacts will arise during the construction period.

16.1.6                            Landscape and visual impact

16.1.6.1            Due to the urban nature of the surroundings and the provision of the landscaped promenade, adverse impacts on the local surroundings should be minimal.

16.1.7                            Environmental Monitoring and Audit

16.1.7.1            An outline environmental monitoring and audit programme has been developed to ensure that construction phase mitigation measures are being implemented and the residual impacts are within acceptable limits. The EM&A Manual is issued as a separate document.

 


Table 16.1 :  Schedule of Impacts and Mitigation Measures

No.

Activity

Mitigation/EIA Recommendations

Responsibility for Implementation

Location
Duration completion
of measures

Implementation Stage
C : Construction
D : Design

Permit Conditions apply to

Relevant Guidelines Legislation

1

Operational Traffic Noise*

The openings of ventilation buildings or ventilation shafts should be placed carefully and ideally should be such that they are not facing directly onto any NSR.

Various

Area Wide, Proposals at design stage for Implementation during construction

D/C

N/A

--

2

Operational Air Quality

Air intakes for commercial/G/IC buildings should be placed such that they are at locations where contours indicate AQOs are met.

ArchSD/Private sector +

CRIII

During development of sites

Completion of CRIII

Development of CRIII

Carry forward to design stage

6

3

Operational Water Quality

Provision of grit traps for surface drainage

 

TDD’s Contractor

New roads and paved areas

During construction

End of construction

C

P, R, A, C

7

4

Operational Landscape and Visual

Operational stage landscape and visual mitigation measures should include +

 

 

 

 

 

 

 

·          Implementation of the Waterfront Promenade, Statue Square Corridor, Historic Corridor, Civic Corridor, Arts and Entertainment Corridor, Streetscape Network, Landscape Decks, and Supplementary Landscape Spaces;

Various

Area wide, proposals at design stage for implementation during construction

D/C

P

--

 

 

·          provision of a legible, integrated pedestrian circulation system linking major activity nodes, reinforcing links with adjoining areas, and providing an international quality hard and soft landscape treatment;

 

 

 

 

 

 

 

·          provision of a grade separated pedestrian system to minimise vehicular/ pedestrian conflict;

 

 

 

 

 

 

 

·          provision of an integrated network of local and regional open spaces for passive and active recreation;

 

 

 

 

 

 

 

·          preservation of selected architectural features;

 

 

 

 

 

 

 

·          preservation insitu of existing significant vegetation, principally the two Banyan Trees flanking the Tamar Site;

 

 

 

 

 

 

 

·          new roads to incorporate suitable streetscape amenity and landscape planting to minimise visual and environmental impacts;

 

 

 

 

 

 

 

·          existing roads upgraded to ‘marry’ with the proposed landscape framework;

·           Hydroseeding of reclamation if there is no immediate use of the site, periphery of the reclamation;

·          Designated service corridors beneath footpaths to prevent potential impacts upon vegetation during services maintenance;

 

 

 

 

 

 

 

·          Sensitively designed colour themes to footpath paving areas; and

·          Sensitively designed seawall to enhance the recreational value of the future promenade can be included.

Various

Area wide, proposals at design stage for implementation during construction

D/C

P

--

5

Construction Noise Control Requirements

Use of the following quiet mechanical equipment for construction
works :

TDD’s Contractor

Works Area

During construction

End of construction

C

P, R, A, C

-

 

 

·          air compressor;

 

 

 

 

 

 

·          paver;

 

 

 

 

 

 

 

·          hand held breaker;

 

 

 

 

 

 

 

·          breaker, excavator mounted;

 

 

 

 

 

 

 

·          bulldozer;

 

 

 

 

 

 

 

·          concrete lorry mixer;

 

 

 

 

 

 

 

·          concrete pump;

 

 

 

 

 

 

 

·          crane;

 

 

 

 

 

 

 

·          dump truck;

 

 

 

 

 

 

 

·          excavator/ loader;

 

 

 

 

 

 

 

·          grader;

 

 

 

 

 

 

 

·          lorry ;

 

 

 

 

 

 

 

·          poker;

 

 

 

 

 

 

 

·          road roller;

 

 

 

 

 

 

 

·          vibratory roller;

 

 

 

 

 

 

 

Use of noise barriers (in the form if purpose built site hoarding of 3 - 5 m height and surface density of at least 7 kgm2 with cranked top) for the following works:

·          Hong Kong Station Extended Overrun Tunnels to north of Central Barracks.

·          North Island Line Protection Works to north of Central Barracks;

·          Road/Drainage Works to north of Central Barracks;

·          Culvert F Piling Works to north of City Hall.

TDD’s Contractor

Work Sites as stated
Start of activity stated
End of activity stated

C

P, A

 

 

 

·          Only well-maintained plant should be operated on-site and plant should be serviced regularly during the construction programme.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

4

 

 

·          Silencers or mufflers on construction equipment shoud be utilised and should be properly maintained during the construction programme.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

4

 

 

·          Mobile plant, if any, should be sited as far away from noise sensitive facilities as possible.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

4

 

 

·          Machines and plant (such as trucks) that may be in intermittent use should be shut down between works periods or should be throttled down to a minimum.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

4

 

 

·          Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from nearby noise sensitive  facilities.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

4

 

 

·          Material stockpiles and other structures should be effectively utilised, wherever practicable, in screening noise from on-site construction activites.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

4

6

Construction Air Quality Control Requirements

·          Strictly limit truck speed on site to below 10 km per hour and water spraying to keep the haul roads in wet condition.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6,7

 

 

·          Twice daily watering of the site with active operations when the weather and the work site are dry.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6,7

 

 

·          Watering during excavation and material handling.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6,7

 

 

·          Provision of vehicle wheel and body washing facilities at the exit points of the site, combined with cleaning of public roads where necessary.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6,7

 

 

·          Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6,7

 

 

·          Covers for dusty stockpiles

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6

 

 

·          All plant shall be maintained ot prevent any undue air emmissions

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

6

7

Construction  Water Quality Control Requirements

Specific Meaures Associated with Dredging Works

 

 

 

 

 

 

·          the use of closed clamshell (water-tight) grab dredgers to remove seriously contaminated material such that the amount of SS and other pollutants released from the marine mud and pore water can be minimised;

TDD’s Contractor

Whole reclamation area

During reclamation works

End of reclamation works

C

R

7

 

 

·          the prohibition of stockpiling of any moderately or seriously contaminated marine sediment, and careful control of stockpiling of any uncontaminated sediment to prevent runoff, resuspension and odour nuisances; and

 

 

 

 

 

 

·          the control of dredging and bulk reclamation filling rates within acceptable limits.  Based upon the construction sequence developed for this study the maximum dredging and filling rates adopted for Final Reclamation Area East were :

        Maximum Dredging Rate : 184 m2/hour

        Maximum Daily Filling Rate : 17,727 m3/day

(for bulk reclamation filling)
Maximum dredging and filling rates for other reclamation sites should take account of information contained in Table 10.14 and the envisaged construction sequence.

 

 

 

 

 

 

 

·          No dredging should take place under very bad weather conditions.

·          Silt curtain around dredging sites to be provided as necessary.

 

 

 

 

 

 

 

Specific Measure for Marine Disposal of Dredged Materials and Maine Sand Filling Works

TDD’s Contractor

Whole reclamation area

During reclamation works

End of reclamation works

C

R

7

 

 

·          all vessels should be sized such that adequate clearance is maintained between vessels and the sea bed at all states of the tide to ensure that undue turbidity is not generated by turbulence from vessel movement or propeller wash;

 

 

 

 

 

 

·          all hopper barges and dredgers should be fitted with tight fitting seals to their bottom openings to prevent leakage of material;

 

 

 

 

 

 

 

·          loading of hopper barges should be controlled to prevent splashing of dredged or filling material to the surrounding water, and barges or hoppers should not be filled to a level which will cause the overflow of materials or polluted water during loading or transportation;

 

 

 

 

 

 

 

·          the works should cause no visible foam, oil, grease, scum, litter or other objectionable matter to be present on the water within the site or dumping grounds;

TDD’s Contractor

Whole reclamation area

During reclamation works

End of reclamation works

C

R

7

 

 

·          bulk filling should be carried out, where feasible, behind completed seawall to above high water mark.  In general and where physically practical, filling should not be carried out without the seawall having been substantially completed for a distance of 100m – 200m ahead of filling; and

 

 

 

 

 

 

 

·          fill materials should comply with technical specification requirements and be taken from approved sources only.  The maximum fines content of marine sand should be limited to 5% as assumed in the water quality assessments.

 

 

 

 

 

 

 

·          transport of contaminated mud (or filling material) to the marine disposal site (or works site) should, wherever possible, be by split barge of not less than 750 m3 capacity, well maintained and capable of rapid opening and discharge at the disposal site;

·          the dredged material should be disposed in the pit by bottom dumping, at a location within the pit specified by the MFC;

·          discharge should be undertaken rapidly and the hoppers should then immediately be closed. Material adhering to the sides of the hopper should not be washed out of the hopper and the hopper should remain closed until the barge next return to the disposal site;

·          the dumping vessel is not required to station but will be guided by the site staff managing the disposal facility.  The vessel crew should be familiar with such operational procedures;

·          monitoring of the barge loading to ensure that loss of material does not take place during transportation; and

 

 

 

 

 

 

 

·          Transport barges or vessels shall be equipped with automatic self-monitoring devices.

 

 

 

 

 

 

 

Specific Measures Associated with Dredging and Filling Works when CRIII Dredging and Filling Works are being constructed concurrently with WDII Dredging and Filling Works

 

 

 

 

 

 

 

·          deployment of silt curtains around the dredging and fill release points to contain SS within the construction site during dredging and filling;

·          deployment of silt screens at the cooling water intakes and WSD salt water intakes to further minimise the intake of SS within the sea water.

TDD’s Contractor

Reclamation Areas as appropriate
When CRIII and WDII - Dredging and Filling Works occur concurrently
End of Concurrent Works

C

R

-

 

 

Specific Measures Associated with Floating Debris

The result of the floating debris simulation has shown that the intermediate layout of the proposed reclamation has potential to trap floating rubbish. Monitoring and control of the construction activities should be taken to prevent the release of construction waste and rubbish from the construction site. Collection of floating debris should be carried out at least once every day by the CRIII Contractor, and more frequently (two or three times per day) at the water body south of the Initial Reclamation Area West and near the cooling water intakes where large substances could block the screens and filter pipes of the intakes and reduce their efficiency. Debris should be collected and taken to landfill sites for disposal.

TDD’s Contractor

Whole reclamation area

During construction

At end of construction

C

R

-

 

 

Specific Measures for Dealing with Culvert L Outfall at Completion of CRIII Eastern Seawall

 

 

 

 

 

 

 

As a mitigation measure, to avoid the accumulation of water borne pollutants within a temporary embayment to the east of CRIII, an impermeable barrier, suspended from a floating boom on the water surface and extending down to the seabed, will be erected by the CRIII Contractor on completion of the CRIII eastern seawall. The barrier will channel the stormwater discharge flows from Culvert L to the outside of the embayment.  The CRIII Contractor will maintain this barrier until the WDII Contractor takes possession of this site, whereupon the WDII Contractor will takeover the maintenance of this barrier until the reclamation works in this area are carried out and the new Culvert L extension is constructed.

TDD's Consultant

Culvert L Outfall
During Construction
To handover to WDII Contractor

C

R

--

 

 

Construction Run-off and Drainage

 

 

 

 

 

 

 

·          Control of Site Surface Runoff:

-                                  Surface run-off from construction sites should be discharged into storm drains via adequately designed sand/silt removal facilities such as sand traps, silt traps and sediment basins. Channels or earth bunds or sand bag barriers should be provided on site to properly direct stormwater to such silt removal facilities. Perimeter channels at site boundaries should be provided where necessary. Catchpits and perimeter channels should be constructed in advance of site formation works and earthworks.

-                                  Silt removal facilities, channels and manholes should be maintained.

TDD’s Contractor

Works Area

During construction

End of construction

C

P,R,A,C

7

 

 

-  Construction works should be programmed to minimise soil excavation works in rainy seasons (April to September). If excavation in soil cannot be avoided, temporarily exposed slope surfaces should be covered and temporary access roads should be protected by crushed stone or gravel, as excavation proceeds. Intercepting channels should be provided.

-  Earthworks final surfaces should be well compacted and the subsequent permanent work or surface protection should be carried out immediately after the final surfaces are formed to prevent erosion caused by rainstorms. Appropriate drainage such as intercepting channels should be provided where necessary.

-  Measures should be taken to minimise the ingress of rainwater into trenches. If excavation of trenches in wet seasons is necessary, they should be dug and backfilled in short sections. Rainwater pumped out from trenches or foundation excavations should be discharged into storm drains via silt removal facilities.

-  Open stockpiles of construction materials should be covered.

-  Manholes should be adequately covered and temporarily sealed.

 

 

 

 

 

 

 

·          Groundwater

-  Groundwater pumped out of tunnels or caverns should be discharged into storm drains after the removal of silt.

 

 

 

 

 

 

 

·          Boring and Drilling Water

-  Water used in ground boring and drilling for site investigation or rock/soil anchoring should as far as practicable be recirculated after sedimentation. Wastewater should be discharged into storm drains via silt removal facilities.

TDD’s Contractor

Work Area

During construction

End of construction

C

P,R,A,C

7

 

 

·          Wastewater from Concrete Batching and Precast Concrete Casting

-  Wastewater generated from the washing down of mixer trucks and drum mixers and similar equipment should wherever practicable be recycled. The discharge of wastewater should be kept to a minimum.

-  To prevent pollution from wastewater overflow, the pump sump of any water recycling system should be provided with an on-line standby pump of adequate capacity and with automatic alternating devices.

-  Under normal circumstances, surplus wastewater may be discharged into foul sewers after treatment in silt removal and pH adjustment facilities (to within the pH range of 6 to 10). Disposal of wastewater into storm drains will require more elaborate treatment. Surface run-off should be segregated from the concrete mixing and casting yard area as much as possible, and diverted to the stormwater drainage system. Surface run-off contaminated by materials in a concrete mixing area or casting yard should be adequately treated before disposal into stormwater drains.

 

 

 

 

 

 

 

·          Wheel Washing Water

-  All vehicles and plant should be cleaned before they leave the construction site. A wheel washing bay should be provided at every site exit if practicable and wash-water should have sand and silt settled out or removed before discharging into storm drains. The section of construction road between the wheel washing bay and the public road should be paved with backfall to reduce vehicle tracking of soil and to prevent site run-off from entering public road drains.

TDD’s Contractor

Work Area

During construction

End of construction

C

P,R,A,C

7

 

 

·          Bentonite Slurries

-  Bentonite slurries should be reconditioned and reused wherever practicable. If the disposal of a certain residual quantity cannot be avoided, the used slurry may be disposed of at the marine spoil site subject to obtaining a marine dumping licence from EPD (on a case-by-case basis).

-  If the used bentonite slurry is intended to be disposed of through the public drainage system, it should be treated to the respective effluent standards applicable to foul sewers, storm drains or the receiving waters as set out in the WPCO Technical Memorandum on Effluent Standards.

 

 

 

 

 

 

 

·          Wastewater from Building Construction

-  Before commencing any demolition works, all sewer and drainage connections should be sealed to prevent building debris, soil, sand etc. from entering public sewers/drains.

-  Wastewater generated from building construction activities including concreting, plastering, internal decoration, cleaning of works and similar activities should not be discharged into the stormwater drainage system. If the wastewater is to be discharged into foul sewers, it should undergo the removal of settleable solids in a silt removal facility, and pH adjustment as necessary.

 

 

 

 

 

 

 

·          Licensing of Construction Site Discharges within Water Control Zones

-  All discharges into any drainage or sewerage systems, or inland or coastal waters, or into the ground (e.g. from septic tanks) within a Water Control Zone are controlled under the Water Pollution control Ordinance (WPCO), except the discharge of domestic sewage into foul sewers or the discharge of unpolluted water into storm drains or into the waters of Hong Kong. Construction site discharges are controlled under the WPCO.

-  Discharges controlled under the WPCO must comply with the terms and conditions of a valid WPCO licence.

 

 

 

 

 

8.

Construction Waste Control Requirements

Specific Measures Associated with Marine sediments

 

 

 

 

 

 

 

In accordance with the WBTC No. 3/2000, the seriously contaminated material must be dredged and transported with great care.  Mitigation measures, includeding the use of close-grab dredgers, shall be incorporated.

The dredged contaminated sediment must be effectively isolated from the environment upon final disposal and shall be disposed of at the East Sha Chau Contaminated Mud Pits.

TDD's Contractor

Whole Reclamation Area
During Reclamation Works
End of Reclamation Work

C

R

7

 

 

Segregation and Disposal of Wastes

 

 

 

 

 

 

 

·          inert demolition/construction waste material when deemed suitable for reclamation or land formation should be re-used on-site;

·          non-inert demolition / construction waste material should be disposed of at landfills;

·          chemical waste as defined by Schedule 1 of the Waste Disposal (Chemical Waste) (General) Regulation, should be stored in accordance with approved methods defined in the Regulation and Code of Practice and the chemical waste disposed of at the Chemical Waste Treatment Facility located at Tsing Yi or an approved recycler;

·          general refuse should be recycled where possible or disposed of at public landfill.

TDD's Contractor

Works Areas
During Construction
End of Construction

C

P, R, A, C

1,8, 9

 

 

Storage, Collection and Transport of Waste

·          wastes should be handled and stored in a manner which ensures that they are held securely without loss or leakage thereby minimising the potential for pollution. Release of these potential pollutants into marine waters during storage, handling or barge transportation should not be permitted as introduction of polluted waters is likely to have detrimental effects on water quality and water sensitive receivers;

·          only reputable waste hauliers authorised to collect the specific category of waste concerned should be employed;

·          appropriate measures should be employed to minimise windblown litter and dust during transportation by using enclosed bins, covering trucks or transporting wastes in enclosed containers;

·          the necessary waste disposal permits and registrations should be obtained from the appropriate authorities, if they are required, in accordance with the Waste Disposal Ordinance (Cap 354), Waste Disposal (Chemical Waste) (General) Regulation (Cap 354) and the Crown Land Ordinance;

·          collection of general refuse should be carried out frequently, preferably daily;

·          waste should only be disposed of at licensed sites and the civil engineering contractor should develop procedures to ensure that illegal disposal of wastes does not occur;

·          waste storage areas should be well maintained and cleaned regularly;

·          records should be maintained of the quantities of wastes generated, recycled and disposed, determined by weighing each load or other method; and

·          A “trip ticket” system should be implemented, if required by Government.

TDD's Contractor

Works Areas
During Construction
End of Construction

C

P, R, A, C

1, 8, 9


 

No.

Activity

Mitigation/EIA Recommendations

Responsibility for Implementation

Location
Duration completion
of measures

Implementation Stage
C : Construction
D : Design

Permit Conditions apply to

Relevant Guidelines Legislation

9

Construction Landscape and Visual Control Requirements

Construction stage landscape and visual mitigation measures should include :

·          Minimising contractors accesses and working areas as far as possible;

·          Protection and retention of existing vegetation where possible in accordance with the Hong Kong Government "A Guide to Tree Planting and Maintenance in Urban Hong Kong, Section 5" Care of Trees on Development Sites' and the Country Parks Ordinance

·          Transplanting of trees where appropriate;

·          Advance planting and visual screening;

·          Conservation of top soil;

·          Design of the temporary works areas so as to optimise eventual use as promenade and public open space; and

·          Sensitively designed site hoarding.

TDD's design consultant

Area wide during design and contract preparation

D

P, R, A, C

11, 12, 13,14

10

Monitoring and Audit

To be carried out in accordance with the Schedule in the EM and A Manual

TDD*/Contractor/RSS

Works areas

During construction

End of construction and within one year of operational phase

C/O

P, R, A, C

1

 

 

 

TDD’s design consultant

Area wide during design and contract preparation

D

P, R, A, C

11,12,13,14

1.         Environmental Impact Assessment Ordinance Technical Memorandum (EIAO)

2.         HKPSG

3.         ExCo Criteria for ITR

4.         Noise Control Ordinance

5.         The ProPECC Note PN2/93 (Construction Noise daytime limits)

6.         Air Pollution Control Ordinance (APCO)

7.         Water Pollution Control Ordinance (WPCO)(Cap. 358)

8.         Waste Disposal Ordinance (Cap 354)

9.         Waste Disposal (Chemical Waste)(General) Regulation (Cap 354)

10.       Land Ordinance (Cap 28)

11.       WBTC 25/92 Allocation of Space for Urban Trees

12.       WBTC 25/93 Control of Visual Impact of Slopes

13.       WBTC 18/94 Management and Maintenance of both Natural Vegetation and Landscape Works

14.       WBTC 24/94 and PELBTC 3/94 “Tree Preservation”

15.           Antiquities and Monuments Ordinance (Cap 53)

P          Primary and District Distributor Roads

R          Reclamation

A          North Island Line Protection Works

C          Central and Wanchai Bypass

+          These items should be excluded from any Environmental Permit conditions as these refer to future development of the area (which is not designated under the EIAO), and are not related to reclamation and dredging activities which are designated, and can hence be controlled through EP conditions.

*        Normally undertaken by a specialist monitoring team employed directly by the proponent and audited by the Environmental Works Checker.