Agreement No. CE 21/2012 (WS)

 

Desalination Plant at Tseung Kwan O –
Feasibility Study

 

Environmental Impact Assessment Report

 

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Table of Content

 

Chapter                                                                                                                                            

1

Introduction

1.1

Background

1.2

Purpose and Nature of the Project

1.3

Purpose of the EIA

1.4

Location and Scale of the Project & History of the Site

1.5

The Scoping of Environmental Issues

1.6

Structure of this Report

2

Consideration of Alternatives

2.1

Need of the Project

2.2

Consideration of Alternative Sites – Site Selection

2.3

Consideration of Alternative Development Options

2.4

Consideration of Alternative Construction Methods

2.5

Consideration of Works Sequences

2.6

Selection of Preferred Scenario

3

Project Description

3.1

The Project

3.2

Project Design

3.3

Project Components

3.4

Construction of Project

3.5

Project Operation

3.6

Project Summary

3.7

Project Programme

3.8

Concurrent Projects

4

Air Quality Impact

4.1

Introduction

4.2

Statutory Requirements and Evaluation Criteria

4.3

Baseline Condition

4.4

Study Area and Identification of air Sensitive Receivers

4.5

Potential Sources of Impacts

4.6

Evaluation of Impacts

4.7

Cumulative Impacts

4.8

Mitigation Measures

4.9

Residual Impacts

4.1

Environmental Monitoring and Audit

4.11

Conclusions

5

Noise

5.1

Introduction

5.2

Relevant Legislation and Guidelines

5.3

Description of the Noise Environment

5.4

Potential Sources of Impact

5.5

Assessment Methodology

5.6

Evaluation of Impacts

5.7

Mitigation Measures

5.8

Cumulative Impact

5.9

Residual Impact

5.1

Environmental Monitoring and Audit

5.11

Conclusions

6

Water Quality Impact

6.1

Introduction

6.2

Legislation Requirements and Guildline

6.3

Baseline Condition

6.4

Water Quality Sensitive Receivers

6.5

Assessment Criteria

6.6

Assessment Methodology

6.7

Potential Sources of Impact

6.8

Impact Assessment

6.9

Mitigation Measures

6.1

Residual Impact

6.11

Mitigation Measures

6.12

Environmental Monitoring and Audit

6.13

Conclusions

7

Sewerage and Sewage Treatment Implication

7.1

Relevant Legislative Requirements

7.2

Assessment Methodology

7.3

Existing Sewerage Facilities and Planned Sewerage in the Area

7.4

Estimated Sewage Flow

7.5

Proposed Sewerage Disposal Strategy

7.6

Mitigation Measures

7.7

Environmental Monitoring and Audit

7.8

Conclusion

8

Waste Management Assessment

8.1

Introduction

8.2

Legislation Requirements and Evaluation Criteria

8.3

Expected Waste Arisings during the Construction Phase

8.4

Expected Waste Arisings during the Operation Phase

8.5

Mitigation Measures

8.6

Residual Environmental Impacts

8.7

Environmental Monitoring and Audit

8.8

Conclusions

8A

Land Contamination Assessment

8A.1

Introduction

8A.2

Legislation Requirements and Evaluation Criteria

8A.3

Project Design and Site Setting

8A.4

Identification of Sensitive Receivers

8A.5

Assessment methodology

8A.6

Land Contamination Impact Evaluation and Mitigation Measures

8A.7

Conclusion

 

 

 

 

9

Ecological Impact Assessment (Terrestrial & Aquatic)

9.1

Introduction

9.2

Legislative Requirements & Evaluation Criteria

9.3

Baseline Conditions

9.4

Impact Identification

9.5

Impact Assessment

9.6

Impact Evaluation

9.7

Mitigation Measures

9.8

Cumulative Ecological Impact

9.9

Residual Impact

9.1

Environmental Monitoring & Audit (EM&A)

9.11

Conclusions

10

Fisheries Assessment

10.1

Introduction

10.2

Relevant Legislation and Assessment Criteria

10.3

Baseline Conditions & Fisheries Sensitive Receivers

10.4

Assessment Methodology

10.5

Potential Impacts & Impact Assessment on Fisheries Resources

10.6

Impact Evaluation

10.7

Mitigation Measures

10.8

Residual Impacts

10.9

Cumulative Impacts

10.1

Environmental Monitoring & Audit

10.11

Conclusions

11

Landscape and Visual Impact Assessment

11.1

Introduction

11.2

Environmental Legislation, Standards and Guidelines

11.3

Scope of the Study

11.4

Review of Planning & Development Control Framework

11.5

Methodology - Landscape Impact Assessment

11.6

Methodology - Visual Impact Assessment

11.7

Landscape Baseline Conditions

11.8

Visual Baseline Conditions

11.9

Identification of Potential Sources of Landscape and Visual Impacts

11.1

Landscape Impact Assessment

11.11

Visual Impact Assessment

11.12

Conclusion

12

Landfill Gas Hazard Assessment

12.1

Introduction

12.2

Landfill Gas Risk Assessment Methodology

12.3

Nature of the SENT Landfill and TKO Stage II/III and I Restored Landfills

12.4

Proposed Desalination Plant and Fresh Water Mains

12.5

Potential for the Development to Intercept Landfill Gas

12.6

Qualitative Assessment of Risks due to Landfill Gas

12.7

Recommended Precautionary and Protection Measures for the Construction and Operation of the Desalination Plant and Fresh Water Mains

12.8

Conclusions

13

Hazard to Life Assessment

13.1

Introduction

13.2

QRA for the On-site Transport, Storage and Use of Chlorine at the Proposed Desalination Plant

13.3

QRA for Off-site Transport of Chlorine

13.4

QRA for Use, Storage and Transport of Sodium Hypochlorite

13.5

Transport (On-site and off-site), Storage, Handling of Cryogenic and Pressurised Liquid Carbon Dioxide

13.6

Other Risk Issues Associated with the Proposed Desalination Plant

13.7

Cumulative Risk Assessment

13.8

Uncertainty Analysis

13.9

Conclusions and Recommendations

13.1

References

14

Environmental Monitoring & Audit Measures

14.1

Introduction

14.2

Objectives of EM&A

14.3

Air Quality

14.4

Noise

14.5

Water Quality

14.6

Sewerage and Sewage Implication

14.7

Waste Management

14.8

Land Contamination

14.9

Ecology

14.1

Fisheries

14.11

Landscape and Visual Impact

14.12

Landfill Gas Hazard

14.13

Hazard to Life

14.14

Summary of EM&A Measures

15

Summary of Environmental Outcomes and Conclusions

15.1

Introduction

15.2

Considerations of Alternatives

15.3

Air Quality Impact

15.4

Noise Impact

15.5

Water Quality Impact

15.6

Sewerage and Sewage Treatment Implication

15.7

Waste Management Implication

15.8

Land Contamination Assessment

15.9

Ecological Impact (Terrestrial and Aquatic)

15.1

Fisheries Impact

15.11

Landscape & Visual Impacts

15.12

Landfill Gas Hazard

15.13

Hazard to Life

15.14

Environmental Outcomes and Environmental Benefits of the Project

 

 

 

Compliance Checklist

 

Appendices

Annex 5A

Photos of Existing NSRs

Annex 5B

Preliminary Construction Programme

Annex 5C

Construction Plant Inventory (Unmitigated Scenario)

Annex 5D

Construction Noise Assessment (Unmitigated Scenario)

Annex 5E

Construction Plant Inventory (Mitigated Scenario)

Annex 5F

Construction Noise Assessment (Mitigated Scenario)

Annex 6A

Water Modelling Method Statement

Annex 6B

Result of Construction Phase Sediment Plume Modelling

Annex 6C

Detailed Result of CORMIX Modelling

Annex 6D

Result of Operational Phase Effluent Discharge Modelling

Annex 6E

Result of Operational Phase Saline Discharge Modelling

Annex 6F

Material Safety Data Sheet of Typical Antiscalant

Annex 6G

Seawater Sampling Result

Annex 6H

Result of Sediment Testing and Elutriate Test

Annex 7A

Layout Plan of Proposed Desalination Plant

Annex 7B

Details of Hydraulic Calculation

Annex 7C

Hydraulic Modelling Results

Annex 8A

C&DMMP

Annex 8B

Sediment Quality Result between September and October 2013

Annex 8A.1

Site Investigation Record

Annex 8A.2

Site Walkover Checklist

Annex 9A

Baseline Ecological Survey Report

Annex 9B

Supplementary Ecological Survey Report

Annex 12A

Landfill Gas Monitoring Result

Annex 12B

Groundwater Monitoring Result

Annex 12C

Detailed Record of Underground Utilities

Annex 13A

PHAST Flat Terrain Dispersion Modelling Results for On-site Chlorine Hazard Assessment

Annex 13B1

CFD Modelling Results for On-site Chlorine Hazard Assessment (with Offsite Impact)

Annex 13B2

CFD Modelling Results for On-site Chlorine Hazard Assessment – 0.3 kg/s and 0.56 kg/s continuous releases

Annex 13C

Application of Dispersion Modelling Results in QRA for On-site Chlorine Hazard Assessment

Annex 13D

Marine Population Survey

Annex 13E

Seismic Hazard Assessment

Annex 13F

Tsunami Hazard Assessment

Annex 13G

Fault Tree Analysis of On-site Chlorine Release

Annex 13H

Fault Tree Analysis of Off-site Chlorine Release

Annex 13I

Fault Tree Analysis of On-site Sodium Hypochlorite Release

Annex 13J1

Figures for Liquid Carbon Dioxide Assessment

Annex 13J2

HAZID Worksheet and Relevant Drawings

Annex 13K

Uncertainty Analysis

Annex 13L

List of Major Assumptions

Annex 14A

Implementation Schedule of Recommended Mitigation Measures

 

Drawings

Figure 1.1

Location of the Proposed Desalination Plant at Tseung Kwan O

Figure 2.1

Shortlisted Location for Constructing a New Desalination Facility in Hong Kong

Figure 2.2

Various Options of Desalination Plant Footprint

Figure 2.3a

Slope Mitigation Works - Option 1

Figure 2.3b

Slope Mitigation Works - Option 2

Figure 2.3c

Slope Mitigation Works - Option 3

Figure 2.3d

Slope Mitigation Works - Option 4

Figure 2.4a

Approximate Location of the Proposed Algnment of the Flexible Barrier

Figure 2.4b

Illustration of Hazard Mitigation Works

Figure 2.4c

Example of Flexible Barrier for Natural Terrain Hazard Mitigation

Figure 2.4d

Illustration of Hazard Mitigation Works

Figure 2.4e

Illustration of Hazard Mitigation Works

Figure 2.4f

Illustration of Hazard Mitigation Works

Figure 2.4g

Illustration of Hazard Mitigation Works

Figure 2.5

Proposed Sewerage System

Figure 2.6

Submarine Outfall at Different Locations

Figure 2.7

Submiarine Outfallat Different Locations

Figure 2.8

Location of the Proposed Desalination Plant at Tseung Kwan O

Figure 2.9

Dredging Area for the Intake and Outfall Pipe

Figure 3.1

Desalination Plant Layout Plan

Figure 3.2

Location Plan for Slope Mitigation Works

Figure 3.3a

Illustrations of Potential Slope Mitigation Works

Figure 3.3b

Illustrations of Potential Slope Mitigation Works

Figure 3.3c

Illustrations of Potential Slope Mitigation Works

Figure 3.3c(cont')

Illustrations of Potential Slope Mitigation Works

Figure 3.4

Location of the Proposed Desalination Plant at Tseung Kwan O

Figure 3.5

Process Flow Diagram

Figure 4.1

Location of Representative Air Sensitive Receivers

Figure 5.3a

The 300m Study Area For Noise Impact Assessment

Figure 5.3b

Locations of Existing Noise Sensitive Receivers For Assessment (Page 1 of 4)

Figure 5.3c

Locations of Existing Noise Sensitive Receivers For Assessment (Page 2 of 4)

Figure 5.3d

Locations of Existing Noise Sensitive Receivers For Assessment (Page 3 of 4)

Figure 5.3e

Locations of Existing Noise Sensitive Receivers For Assessment (Page 4 of 4)

Figure 5.3f

Locations of Planned Noise Sensitive Receivers For Assessment

Figure 5.4a

Locations of Pipe Jacking Works Area

Figure 5.7a

Locations of Construction Areas Yielding Residual Impacts During School Hours (Sheet No. Of 1)

Figure 5.7b

Locations of Construction Areas Yielding Residual Impacts During School Hours (Sheet No. Of 2)

Figure 5.7c

Locations of Noise Enclosure for Sawcutting Pavement

Figure 5.7d

Locations of Noise Enclosure for Sawcutting Pavement

Figure 5.7e

Locations of Noise Enclosure for Sawcutting Pavement

Figure 5.8a

Indicative Arrangement of Three Workfronts

Figure 5.8b

Indicative Arrangement of Four Workfronts

Figure 6.1

Water Sensitive Receivers of the Surrounding Environment

Figure 6.2

Model Output Location

Figure 6.3

Location of Geophysical Survey Stations

Figure 6.4

Indicative Layout Plan for Deployment of Silt Cutrains For Dredging at Seawater Intake

Figure 6.5

Indicative Layout Plan for Deployment of Silt Cutrains For Dredging at Submarine Outfall

Figure 6.6

Maximum SS Elevation at Bottom Layer in Wet Season

Figure 6.7

Maximum SS Elevation at Bottom Layer in Dry Season

Figure 6.8a

Change in Salinity at Bottom Layer in Dry Season, Spring Tide

Figure 6.8b

Change in Salinity at Bottom Layer in Dry Season, Neap Tide

Figure 6.8c

Change in Salinity at Bottom Layer in Wet Season, Spring Tide

Figure 6.8d

Change in Salinity at Bottom Layer in Wet Season, Neap Tide

Figure 6.8f

Anti-scalant

Figure 7.1

Existing Sewerage System

Figure 7.2

Proposed Sewerage System

Figure 8A.1

Site Layout Map

Figure 8A.2a

Reference Aerial Photographs

Figure 8A.2b

Reference Aerial Photographs

Figure 8A.2c

Reference Aerial Photographs

Figure 8A.2d

Reference Aerial Photographs

Figure 8A.3a

Selected Site Photographs

Figure 8A.3b

Selected Site Photographs

Figure 8A.3c

Selected Site Photographs

Figure 8A.3d

Selected Site Photographs

Figure 9.1

Location Plan and Protection Measures for Marsdenia Lachnostoma

Figure 10.1

Location map for Fisheries Sensitive Receivers

Figure 10.2

Distribution of Fishing Operations (all vessels) in Port Survey 2006

Figure 10.3

Distribution of Fishing Operation (adult fish) in Port Survey 2006

Figure 10.4

Distribution of Fishing Production (adult fish & fish fly) in Port Survey 2006

Figure 10.5

Distribution of Fishing Production (fish fly) in Port Survey 2006

Figure 11.1

Aerial Photograph of the Study Area

Figure 11.2

Land Use Zonings in the Study Area

Figure 11.3

Landscape Resources

Figure 11.4a

Representative Photographs of Landscape Resources

Figure 11.4b

Representative Photographs of Landscape Resources

Figure 11.5

Landscape Character Areas

Figure 11.6a

Representative Photographs of Landscape Character Areas

Figure 11.6b

Representative Photographs of Landscape Character Areas

Figure 11.7

Geology of the Study Area

Figure 11.8

Representative Photographs of Local Geology

Figure 11.9

Predicted Visual Envelope and Zone of Visual Influence (ZVI)

Figure 11.10

Locations of Predicted Visual Sensitive Receivers (VSRs)

Figure 11.11a

Representative Photographs of and from select VSRs

Figure 11.11b

Representative Photographs of and from select VSRs

Figure 11.12

Project Layout

Figure 11.13a

Illustrations of Potential Slope Mitigation Works

Figure 11.13b

Illustrations of Potential Slope Mitigation Works

Figure 11.13c

Illustrations of Potential Slope Mitigation Works

Figure 11.13d

Illustrations of Potential Slope Mitigation Works

Figure 11.14

Impacts on Landscape Resources

Figure 11.15

Impacts on Landscape Character Areas

Figure 11.16a

Photomontage from VP1 (High Junk Peak Trail in Clear Water Bay Country  Park, R3)

Figure 11.16b

Photomontage from VP1 (High Junk Peak Trail in Clear Water Bay Country  Park, R3)

Figure 11.17a

Photomontage from VP2 (Island Resort, VSR H6)

Figure 11.17b

Photomontage from VP2 (Island Resort, VSR H6)

Figure 11.18a

Photomontage from VP3 (LOHAS Park, VSR H3)

Figure 11.18b

Photomontage from VP3 (LOHAS Park, VSR H3)

Figure 11.19a

Photomontage from VP4 (Tail on Knoll)

Figure 11.19b

Photomontage from VP4 (Tail on Knoll)

Figure 11.20a

Photomontage from VP5 (Joss House Bay, VSR R5)

Figure 11.20b

Photomontage from VP5 (Joss House Bay, VSR R5)

Figure 11.21a

Vegetation Survey

Figure 11.21b

Vegetation Survey and Photographs

Figure 11.21c

Vegetation Survey and Photographs

Figure 11.21d

Vegetation Survey and Photographs

Figure 11.21e

Vegetation Survey and Photographs

Figure 11.21f

Vegetation Survey and Photographs

Figure 11.21g

Vegetation Survey and Photographs

Figure 11.21h

Vegetation Survey and Photographs

Figure 11.21i

Vegetation Survey and Photographs

Figure 11.21j

Vegetation Survey and Photographs

Figure 11.22

Proposed Greening at TKO Desalination Plant Site

Figure 12.1

Consultation Zone of the SENT Landfill, SENT Landfill Extension, TKO Stage II/III Restored Landfill and TKO Stage 1 Restored Landfill

Figure 12.2

Typical Details of Impermeable Liner at SENT Landfill

Figure 12.3

Location of SENT Landfill Monitoring Points

Figure 12.4

Location of Restored TKO Stage II/III Landfill Monitoring Points

Figure 12.5

Location of Restored TKO Stage I Landfill Monitoring Points

Figure 12.6

Sectional Plan (Geological Cross Section A-A)

Figure 12.7

Sectional Plan (Geological Cross Section B-B)

Figure 12.8

Sectional Plan (Geological Cross Section C-C)

Figure 12.9

Sectional Plan (Geological Cross Section D-D)

Figure 12.10

Consultation Zone of the SENT Landfill Extension and Layout of Desalination Plant

Figure 12.11

Sections

Figure 12.12

Utilities in SENT Landfill Consultation Zone

Figure 12.13

Utilities inTKO Stage II/III Restored Landfill Consultation Zone

Figure 12.14

Utilities in TKO Stage I Restored Landfill Consultation Zone