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