TABLE OF CONTENTS

 

1                    INTRODUCTION 

 

Background

Objectives of the EIA Study

The Approach

Report Structure

 

2                    DESCRIPTION OF THE PROJECT   

 

Project Requirements

Project Location

Environmental Benefits of the Project

Scope of the Project

Consideration of Alternative Options

Construction Methods

Works Pregramme

Long-Term Treatment and Disposal Methods

Related Projects

Public Consultation

 

3                    AIR QUALITY    

 

Introduction

Environmental Legislation, Standards and Guidelines

Baseline Conditions

Sensitive Receivers

Assessment Methodology

Environmental Impact Identification, Prediction and Evaluation

Mitigation of Adverse Environmental Impact

Environmental Monitoring And Audit

 

4                    NOISE IMPACT      

 

Introduction

Environmental Legislation, Policies, Plans, Standards and Criteria

Description of the Environment

Description of Assessment Methodologies

Identification of Environmental Impacts

Prediction and Evaluation of Environmental Impacts

Mitigation of Adverse Environmental Impacts

Definition and Evaluation of Residual Environmental Impacts

Environmental Monitoring and Audit

 


5                    WATER QUALITY IMPACT      

 

Introduction

Environmental Legislation, Standards and Guidelines

Baseline Conditions

Sensitive Receivers

Assessment Methodologies

Identification of Impacts

Prediction and Evaluation of Impact

Mitigation of Adverse Impacts

Residual Environmental Impacts

Environmental Monitoring and Auditing Requirements

 

6                    SEDIMENT CONTAMINATION        

 

Introduction

Environmental Legislation, Standards and Guidelines

Description of The Environment

Assessment Methodologies

Baseline Conditions

Identification, Prediction and Evaluation of Environmental Impacts

Mitigation of Adverse Environmental Impacts

Definition and Evaluation of Residual Environmental Impacts

 

7                    SOLID WASTE MANAGEMENT           

 

Introduction

Environmental Legislation, Policies, Plans, Standards and Criteria

Description of the Environment

Assessment Methodologies

Environmental Impact Identification, Prediction and Evaluation

Mitigation of Adverse Environmental Impacts

Definition and Evaluation of Residual Environmental Impacts

Environmental Monitoring and Audit

 

8                    ECOLOGICAL IMPACT      

 

Introduction

Environmental Legislation, Policies, Plans, Standards and Criteria

Description of the Environment

Terrestrial Ecology

Intertidal Ecology

Subtidal Ecology

Summary of Baseline Conditions

Description of Assessment Methodologies

Identification, Prediction and Evaluation of Environmental Impacts

Mitigation of Adverse Environmental Impacts

Definition and Evaluation of Residual Environmental Impacts

Ecological Monitoring and Audit

References Cited

 

9                    FISHERIES IMPACT      

 

Environmental Legislation, Policies, Plans, Standards and Criteria

Description of the Environment    

Assessment Methodologies

Environmental Impact Identification, Prediction and Evaluation       

Mitigation of Adverse Environmental Impacts           

Definition and Evaluation of Residual Environmental Impacts           

 

10                LANDSCAPE AND VISUAL IMPACT ASSESSMENT        

 

Introduction

Background and Options

Project Description

Assessment Methodology - General

Baseline Survey

Visual Baseline Conditions

Review of Planning and Development Control Framework

Potential Sources of Impacts

Landscape Impact Assessment

Visual Impact Assessment

Mitigation Measures

 

11                ENVIRONMENTAL MONITORING AND AUDIT        

 

Introduction

Air Quality Impact

Noise Impact

Water Quality Impact

Solid Waste Management

Ecological Impact

Fisheries Impact

Visual and Landscape Impact

 

12  IMPLEMENTATION SCHEUDLE OF RECOMMENDED MITIGATION     

MEASURES

 


13CONCLUSIONS AND RECOMMENDATIONS 

 

Introduction

Air Quality

Noise

Water Quality

Sediment Contamination

Solid Waste Management

Ecological Impact

Fisheries Impact

Visual and Landscape Impacts

Overall Conclusion

 

LIST OF TABLES

 

Table 3.1            Hong Kong Air Quality Objectives

Table 3.2            Description of Air Sensitive Receivers (ASRs)

Table 3.3            Predicted TSP concentrations at representative ASRs (Unmitigated)

Table 3.4          Predicted Odour Concentrations at Representative ASRs

Table 3.5          Predicted TSP Concentration at Representative ASRs (Mitigated)

Table 4.1            Area Sensitivity Ratings

Table 4.2            Construction Noise Criteria for Activity other than Percussive Piling

Table 4.3            Acceptable Noise Levels (ANLs) in dB(A)

Table 4.4            Background Noise Levels in the Study Area

Table 4.5            Summary of Representative Noise Sensitive Receivers

Table 4.6Cumulative Construction Noise Levels at Representative NSRs (Without Mitigation)

Table 4.7            Cumulative Operational Noise Levels at Representative (Without Mitigation)

Table 4.8          Cumulative Construction Noise Levels at Representative NSRs (With Mitigation)

Table 4.8a        Cumulative Construction Noise Levels at Representative NSRs (With the Adoption of Quiet Equipment, Restriction on Number of Plant Operating, Use of Noise Screening Structures and Manual Working)

Table 4.9          Cumulative Operational Noise Levels at Representative NSRs (with the Installation of Silencer)

Table 5.1Water Quality Objectives for Marine Waters of Southern Water Control Zone

Table 5.2Ambient and Allowable Elevation in Suspended Sediment Concentrations (mg/L)

Table 5.3Predicted Elevation in Suspended Sediment Concentrations (Unmitigated Scenario)

Table 5.4Calculation of Unionised Ammoniacal Nitrogen Concentrations during Dredging

Table 5.5Modelling Results for the Wet Season Conditions (Unstratified Conditions)

Table 5.6Modelling Results for the Wet Season Conditions (Summer Stratified Conditions)

Table 5.7Modelling Results for the Dry Season Conditions

Table 5.8Modelling Results at Sensitive Receivers

Table 5.9CORMIX Modelling Parameters

Table 5.10aPredicted Water Quality at the Fish Culture Zone (Cumulative Effluent Flow)

Table 5.10bPredicted Water Quality at the Fish Culture Zone (Net Effluent Flow)

Table 5.11Predicted Elevation in Suspended Sediment Concentrations (Mitigated)

Table 6.1Baseline Sediment Quality at Sok Kwu Wan

Table 6.2            Sediment Classification Criteria

Table 6.3            Sediment Quality Criteria for the Classification of Sediment

Table 6.4            Classification of Contaminated Sediments Analysis Results

Table 7.1            Summary of Waste Handling Procedures and Disposal Routes

Table 8.1Bird species of special conservation significance on Lamma Island (from literature review).

Table 8.2Bird species of conservation concern recorded at terrestrial habitats on the study area

Table 8.3Summary of reptile and amphibian species of conservation concern in Lamma Island from literature survey

Table 8.4Additional butterfly species reported in the study area between 1998 and 1999 (P. K. L. Lau, pers. comm.)

Table 8.5Butterfly Species Recorded in the Study Site

Table 8.6Flora and fauna found along the rocky shore of Sok Kwu Wan

Table 8.7Intertidal fauna and algae recorded on preliminary surveys at Sok Kwu Wan, September 1998

Table 8.8Abundance of intertidal fauna and percent cover of algae inside quadrats long the transect near Outfall Option 2 in winter 1998

Table 8.9Abundance of intertidal fauna and percent cover of algae inside quadrats along the transect near Outfall Option 2 in spring 1999

Table 8.10Abundance of intertidal fauna and percent cover of algae inside quadrats along the transect near Outfall Option 2 in summer 1999

Table 8.11Summary of species identified along shoreline of Chiu Keng Wan during preliminary field surveys (ERM, 1998)

Table 8.12Abundance of intertidal fauna inside quadrats along the transect near Outfall Option 2 in 2002

Table 8.12bBird species of conservation concern recorded at rocky shore on the study area

Table 8.13Coral species recorded at Site 1, December 1998

Table 8.14Coral species recorded at Site 2 in December 1998

Table 8.15Construction-stage Impacts

Table 8.16Operation-stage Impacts

Table 8.17Proposed Construction-stage Mitigation Measures

Table 9.1Comparison of Fish Catches and Fry Production at Sok Kwu Wan (Area 101) between 1989-91 and 1996-97 for Vessels of Length less than or equal to 15m

Table 9.2Relative Dollar Values of Catches at Sok Kwu Wan, 1989-91 (Inflated as at 30/4/98) and 1996-97 (Not inflated)

Table 9.3Summary of Impact Evaluation

Table 10.1 Summary of Landscape Impact Assessment in Construction Phase

Table 10.2Summary of Landscape Impact Assessment in Operation Phase

Table 10.3Summary of Visual Impact Assessment in Construction Phase

Table 10.4Summary of Visual Impact Assessment in Operation Phase

Table 10.5Implementation Schedule of Mitigation Measures

Table 12.1            Implementation Schedule of Air Quality Measures

Table 12.2            Implementation Schedule of Noise Measures

Table 12.3            Implementation Schedule of Water Quality Control Measures

Table 12.4            Implementation Schedule of Sediment Contamination Mitigation Measures

Table 12.5            Implementation Schedule of Solid Waste Management Measures

Table 12.6            Implementation Schedule of Ecological Impact Measures

Table 12.7            Implementation Schedule of Fisheries Impact Measures

Table 12.8            Implementation Schedule of Landscape and Visual Impact Measures

 

LIST OF FIGURES

 

Figure 2.1            Site Location Plan

Figure 2.2         Sewage Treatment and Disposal Options Under Outlying Islands Sewerage Master Plan

Figure 2.3         Sewage Treatment Works Locations and Outfall Alignments Under Outlying Islands Sewerage Master Plan and Package J

Figure 2.4         Trunk Sewer Alignments and Pumping Station Locations Under Outlying Islands Sewerage Master Plan and Package J

Figure 2.5         Sewerage Collection System Recommended Under Package J

Figure 2.6         Long Term Sewage Disposal Options Under Outlying Island Sewerage Master Plan Stage II Review

Figure 3.1            Locations of Representative Air Sensitive Receivers

Figure 3.2         Contours of Odour Concentration in OU/5S at 1.5m Above Ground

Figure 3.3         Contours of Odour Concentration in OU/5S at 4.5m Above Ground

Figure 3.4         Contours of 1-Hour Average Total Suspended Particulate Concentrations in ug/m3 at 1.5m Above Ground

Figure 3.5         Contours of 24-Hour Average Total Suspended Particulate Concentrations in ug/m3 at 1.5m Above Ground

Figure 4.1            Locations of Background Noise Measurements

Figure 4.2            Locations of Representative Noise Sensitive Receivers

Figure 4.3            Typical Design of Noise Screening Structure for Sewer Construction

Figure 4.4            Typical Design of Acoustic Shed for Concreting Work of Manhole

Figure 5.1            Sampling Locations of Hydrographic Survey

Figure 5.2            Location of the Submarine Outfall

Figure 5.3            Locations of Emergency Outfalls for the Pumping Stations and STW

Figure 5.4            Initial Dilution of the Effluent Plume (Wet Season – Unstratified Conditions)

Figure 5.4a            Plot of Effluent Plume in Terms of TIN Level

Figure 5.5         Initial Dilution of the Effluent Plume (Wet Season – Summer Stratified Conditions)

Figure 5.6         Initial Dilution of the Effluent Plume (Dry Season – Unstratified Conditions)

Figure 5.7         Downstream TIN Level from Source – Dry Season

Figure 5.8         Downstream TIN Level from Source – Wet Season with Stratification

Figure 5.9a       Typical Design of Silt Curtain

Figure 5.9b       Arrangement of 2-layer Silt Curtains

Figure 5.10       Emergency Discharge Action Plan

Figure 6.1            Sediment Quality Monitoring Locations of Previous Studies at Sok Kwu Wan

Figure 6.2            Sediment Contamination Survey Sampling Locations

Figure 6.3            Dredged Sediment Disposal Arrangement

Figure 8.1            Areas of Conservation Significance in Relation to Sok Kwu Wan Study Area

Figure 8.2            Habitat Map, Sok Kwu Wan

Figure 8.3            Composition of the Epibenthic Community (0-3m in depth) at Site 1

Figure 8.4            Composition of the Epibenthic Community (0-3m in depth) at Site 2

Figure 8.5            Plates 8.1 – 8.3

Figure 8.6            Plates 8.4 – 8.6

Figure 8.7            Plates 8.7 – 8.9

Figure 8.8            Locations of Pumping Station P2 and the moist area with Romer’s Tree Frog

Figure 10.1Landscape Character Areas and Vegetation Areas

Figure 10.2Visual Envelope and Existing Visually Sensitive Receiver Groups

Figure 10.3Photographic Viewpoints

Figure 10.4.1Photographic Record

Figure 10.4.2Photographic Record

Figure 10.4.3Photographic Record

Figure 10.5Landscape Impact at Construction Phase Before Mitigation

Figure 10.6Landscape Impact at Construction Phase Upon Mitigation

Figure 10.7Landscape Impact at Operation Phase Before Mitigation

Figure 10.8Landscape Impact at Operation Phase Upon Mitigation

Figure 10.9 Visual Impact at Construction Phase Before Mitigation

Figure 10.10 Visual Impact at Construction Phase Upon Mitigation

Figure 10.11 Visual Impact at Operation Phase Before Mitigation

Figure 10.12Visual Impact at Operation Phase Upon Mitigation

Figure 10.13Sewerage Treatment Works Landscape Finishes

Figure 10.14.1Proposed Pumping Stations and Sewerage Treatment Works Colour Finishes

Figure 10.14.2Typical Boundary Wall Elevation

Figure 10.15aPhotomontage of the Sewage Treatment Works (STW)

Figure 10.15bPhotomontage of the Sewage Treatment Works (STW)

 

APPENDICES

 

Appendix 2.1                        Horizontal Directional Drilling For Submarine Outfall at Sok Kwu Wan (1, 2)

Appendix 2.2                        Sewage Treatment Works

Appendix 2.3                        Details of Consultations with Various Committees (1, 2, 3, 4)

Appendix 3.1        Calculations of Dust Emission Factors

Appendix 3.2        Sample Output File of the FDM Model

Appendix 3.3        Calculation of Odour Emission Factors and Vent Pipe Information

Appendix 3.4        Sample Output File for ISCST3 Model

Appendix 4.1        Assumed Powered Mechanical Equipment for Pumping Stations (P1a, P1b & P2) Construction (Unmitigated)

Appendix 4.1a      Preliminary Construction Programme

Appendix 4.2        Assumed Powered Mechanical Equipment for Sewer Construction (Unmitigated)

Appendix 4.3        Assumed Powered Mechanical Equipment for Submarine Outfall Construction (Unmitigated)

Appendix 4.4        Assumed Operation Equipment for Pumping Stations P1a, P1b and P2 (Unmitigated)

Appendix 4.5        Predicted Noise Levels from Construction of Pumping Stations (Unmitigated)

Appendix 4.6        Predicted Noise Levels from Sewer Construction (Unmitigated)

Appendix 4.7        Predicted Noise Levels from Submarine Outfall Construction (Unmitigated)

Appendix 4.8        Assumed Powered Mechanical Equipment for Pumping Station P1a Construction (With the Use of Quiet Equipment)

Appendix 4.9        Predicted Noise Levels from Construction of Pumping Stations (With the Use of Quiet Equipment)

Appendix 4.9a      Predicted Noise Levels from Construction of Pumping Station P1a (With the Use of Quiet Equipment and Temporary Noise Barrier)

Appendix 4.10      Assumed Powered Mechanical Equipment for Sewer Construction (With the Use of Quiet Equipment)

Appendix 4.11      Predicted Noise Levels from Sewer Construction (With the Use of Quiet Equipment)

Appendix 4.12      Assumed Powered Mechanical Equipment for Sewer Construction (With the Use of Quiet Equipment and Restriction on Number of Plant Operating)

Appendix 4.13      Predicted Noise Levels from Sewer Construction (With the Use of Quiet Equipment and Restriction on Number of Plant Operating)

Appendix 4.14aAssumed Powered Mechanical Equipment for Pavement Breaking and Trench Excavation with Rock during Sewer Construction (With the Use of Quiet Equipment, Restriction on Number of Plant Operating and Use of Noise Screening Structures)

Appendix 4.14bPredicted Noise Levels from Pavement Breaking and Trench Excavation with Rock during Sewer Construction (With the Use of Quiet Equipment, Restriction on Number of Plant Operating and Use of Noise Screening Structures)

Appendix 4.15aAssumed Powered Mechanical Equipment for Sewer Construction (With the Use of Quiet Equipment, Restriction on Number of Plant Operating and Use of Noise Screening Structures)

Appendix 4.15bPredicted Noise Levels from Sewer Construction (With the Use of Quiet Equipment, Restriction on Number of Plant Operating and Use of Noise Screening Structures and Use of Manual Working)

Appendix 4.16      Assumed Operation Equipment for Pumping Station P1a (With the use of Silencer)

Appendix 5.1                        Results of Hydrographic Survey

-          Dry Season – Float Track Excel Spread Sheets

o        Neap Cycle

o        Spring Cycle

-          Dry Season – Current Rose Diagrams

o        Neap Cycle

o        Spring Cycle

-          Wet Season – Float Track Excel Spread Sheets

o        Spring Cycle

o        Neap Cycle

-          Wet Season – Current Rose Diagrams

o        Spring Cycle

o        Neap Cycle

Appendix 5.1a                        Physico-Chemical Properties of HDD Drilling Fluid

Appendix 5.2                        Demonstration of the Difference in TIN Level with and without the Project

Appendix 5.3                        Calculation of Elevated SS Concentration (Mitigated)

Appendix 5.4                        Outline of Emergency Response Plan

Appendix 8.1                        Plant Species Recorded Within the Study Area at Sok Kwu Wan

Appendix 8.2Bird Species Reported at Sok Kwu Wan (Anon. 1995, Carey 1993, 1994, 1995, 1996, 1998, Hong Kong Bird Watching Society Pers. Comm., P. K. L. Lau Pers. Comm., Carey ET AL. 2001)

Appendix 8.3Bird Species Recorded at Sok Kwu Wan Between 1998 and 1999. Codes of Status and Abundance as in Appendix 8.2 

Appendix 8.4Raw Data of Dive Survey in Sok Kwu Wan

Appendix 8.5Coral Mapping Survey (1, 2)

Appendix 9.1Sok Kwu Wan STW, Outfall and Sewerage Fisheries Survey – Mariculture Operators Interview Questionnaire