Agreement No. CE 72/2019 (EP)

Contaminated Sediment Disposal Facility at West of Lamma Island – Investigation

Environmental Impact Assessment (EIA) Report for the New Contaminated Sediment Disposal Facility
to the West of Lamma Island

EIA REPORT (HTML)

TABLE OF CONTENTS

1. INTRODUCTION

2. PROJECT DESCRIPTION

3. WATER QUALITY IMPACT

4. MARINE ECOLOGICAL IMPACT ASSESSMENT

5. FISHERIES IMPACT ASSESSMENT

6. WASTE MANAGEMENT IMPLICATIONS

7. CULTURAL HERITAGE

8. HAZARD TO HEALTH

9. AIR QUALITY

10. NOISE 7-1

11. ENVIRONMENTAL MONITORING AND AUDIT

12. CONCLUSION

LIST OF FIGURES

Figure 1.1 Indicative Study Area for the Contaminated Sediment Disposal Facility at West of Lamma Island (WL Facility)

Figure 2.1 Typical Design of CAD Facility

Figure 2.2 Typical Design of Nearshore CDF

Figure 2.3a Absolute Environmental Constraints in Southern Waters of Hong Kong

Figure 2.3b Absolute Physical Constraints in Southern Waters of Hong Kong

Figure 2.3c Absolute Social Constraints in Southern Waters of Hong Kong

Figure 2.4a Potential Environmental Constraints in Southern Waters of Hong Kong

Figure 2.4b Potential Physical Constraints in Southern Waters of Hong Kong

Figure 2.4c Potential Social Constraints in Southern Waters of Hong Kong

Figure 2.5 Marine Geophysical Surveys

Figure 2.6 Key Area Identified for Potential CMP Development

Figure 2.7 Location for Site Investigation

Figure 2.8 Preliminary layout of the proposed CMPs

Figure 3.1 Locations of EPD Monitoring Stations and Typhoon Shelter Stations in the Study Area

Figure 3.2 Locations of Sediment Monitoring Data from the EPD Monitoring Stations

Figure 3.3 Locations of the Identified Water Sensitive Receivers (WSRs)

Figure 3.4 Modelled Bathymetry

Figure 3.5 Cross Sections of Selected Major Channels

Figure 3.6 Selected Velocity Points

Figure 4.1 Marine Habitats Identified within the Assessment Area

Figure 4.2 Representative Photographic Records of Substratum from Qualitative Spot Dive Reconnaissance Check and REA Survey

Figure 4.3 Representative Photographic Records of Coral Species and Other Benthos from Qualitative Spot Dive Reconnaissance Check and REA Survey

Figure 4.4 Representative Photographic Records from Drop Camera Survey

Figure 4.5 Location of Finless Porpoise Sightings during Marine Mammal Survey

Figure 5.1 Fisheries Sensitive Receivers

Figure 6.1 Locations for Sediment Sampling and Testing

Figure 7.1 Key Area Identified for Potential CMP Development / MAI Assessment Area

Figure 7.2 Geophysical Survey Area and Location of Sonar Contacts

Figure 7.3 SC008 on historic Admiralty Chart “Hong Kong, No. 1466” dated from 1843 to 1966

Figure 7.4 SC008 overlaid on 2020 Electronic Navigational Chart

Figure 8.1 Indicative Pathways to Potential Contaminant Release

Figure 9.1 Locations of Representative Air Sensitive Receivers in the vicinity of the Project

Figure 10.1 Location of Representative Noise Sensitive Receivers in the vicinity of the Project

LIST OF APPENDICES

Annex 1A Details of the Stakeholder Engagement Activities Undertaken and the Feedback Received

Annex 2A Key Existing, Proposed and Potential Facilities, Utilities and Infrastructure in the vicinity of the Study Area

Annex 3A Method Statement for Water Quality Modelling Assessment

Annex 3B Contour Plots For Construction Phase Sediment Dispersion Modelling

Annex 3C Time Series Plots

Annex 3D Water Current Vector Plots for Operation Phase Change in Flow Regime Assessment

Annex 3E Water Quality Impact Assessment for CMPs located at West of the Key Area

Annex 3F Water Quality Impact Assessment for CMPs during Initial Years of the Project

Annex 4A Marine Ecology - Literature Review

Annex 4B Method Statement for Marine Ecological Survey

Annex 4C Data on Coral Surveys

Annex 4D Data on Subtidal Benthos Survey

Annex 4E Data on Marine Mammal Survey

Annex 5A Fisheries – Literature Review

Annex 5B Method Statement for Fisheries Impact Assessment

Annex 5C Fisheries Survey Results

Annex 5D Adult Fish Production Survey Data

Annex 5E Ichthyoplankton and Fish Post-larvae Survey Data

Annex 5F Commercial Value of Adult Fish and Crustacean Species Recorded from Field Surveys

Annex 6A Proposal for Field Investigation for Assessment of Waste Management Implications

Annex 6B Laboratory Test Reports

Annex 7A Side Scan Sonar and Echo Sound Track Plot

Annex 7B Seabed Features Map

Annex 7C Sonar Contacts Images

Annex 8A Bioaccumulation Assessment

Annex 8B Human Health Risk Assessment Methodology

Annex 11A Implementation Schedule

LIST OF TABLES

Table 2.1 Identified Absolute and Potential Constraints in Southern Waters of Hong Kong

Table 2.2 Evaluation of the Study Area against the Assessment Criteria

Table 2.3 Nearby Physical Constraints

Table 2.4 Tentative Programme of the Project (Indicative for the first three CMPs)

Table 3.1 Summary of Water Quality Objectives for Southern WCZ, Western Buffer WCZ and Victoria Harbour WCZ

Table 3.2 Summary of EPD Routine Water Quality Monitoring Data from Selected Stations within the Assessment Area (1986 – 2020)

Table 3.3 Summary of EPD Routine Water Quality Monitoring Data from Selected Stations within the Assessment Area (1986 – 2020)

Table 3.4 Summary of EPD Typhoon Shelter Water Quality Monitoring Data within the Assessment Area (1986 – 2020)

Table 3.5 Summary of EPD Routine Marine Sediment Quality Monitoring Data within the Assessment Area (1986-2020)

Table 3.6 Summary of EPD Routine Typhoon Shelters and Government Dockyard Sediment Quality Monitoring Data at Selected Locations within the Assessment Area (1986 – 2020)

Table 3.7 Highest Contaminant Levels among all Stations from the Sediment Sampling conducted in mid-2020

Table 3.8 Water Sensitive Receivers (WSRs) in the Vicinity of the Project Site

Table 3.9 WSD’s Water Quality Criteria for Water at Seawater Intakes

Table 3.10 Allowable Increase in SS (mg L-1) Levels for Water Quality Sensitive Receivers and Observation Points

Table 3.11 Allowable DO Depletion (mg L-1) for Water Quality Sensitive Receivers and Observation Points

Table 3.12 Summary of Assessment Criteria for Dissolved Metals and Organic Contaminants

Table 3.13 Predicted SS Elevation at Identified WSRs

Table 3.14 Predicted Sedimentation Flux (g/m2/day) at the Identified Coral WSRs

Table 3.15 Predicted Maximum Conservative Tracer Concentrations at WSRs under various Scenarios

Table 3.16 Estimation of Contaminant Levels at the Most Impacted WSRs

Table 3.17 Predicted Tidal Discharges across Major Nearby Channels

Table 3.18 Predicted Percentile Distribution of Tidal Discharges across Major Nearby Channels (Black: Base Case; Blue: With Project)

Table 3.19 Predicted Instantaneous Tidal Discharges across Major Nearby Channels (Black: Base Case; Blue: With Project)

Table 3.20 Predicted Average Velocity at Selected Locations across Modelled Area

Table 3.21 Predicted Modal Class of Current Direction at Selected Locations across Modelled Area

Table 3.22 Predicted Bed Shear Stress Level at Project Site (Solid Line: Base Case; Dashed Line: With Project)

Table 4.1 Summary of Marine Ecological Survey Schedule

Table 4.2 Summary of Results of Qualitative Spot Dive Reconnaissance Check and REA Survey

Table 4.3 Summary of Drop Camera Survey Results

Table 4.4 Density and Indices of Richness, Evenness and Diversity of Infaunal Assemblages at the Sampling Locations for the Soft Bottom Habitat Surveys at the Study Area during the Dry Season

Table 4.5 Density and Indices of Richness, Evenness and Diversity of Infaunal Assemblages at the Sampling Locations for the Soft Bottom Habitat Surveys at the Study Area during the Wet Season

Table 4.6 Ecological Importance of Recognised Sites of Conservation Importance in the vicinity of the Project

Table 4.7 Ecological Importance of Sub-tidal Hard Bottom Habitat (Coral Communities) in the vicinity of the Project

Table 4.8 Ecological Importance of Subtidal Soft Benthos Assemblages in the vicinity of the Project

Table 4.9 Ecological Importance of Marine Waters in the vicinity of the Project

Table 4.10 Species of Conservation Importance within the Assessment Area

Table 4.11 Approximate Shortest Distance to Marine Ecological Sensitive Receivers in the vicinity of the Project

Table 4.12 Potential Impacts to Marine Ecological Resources (Excluding FP)

Table 4.13 Potential Impacts to Finless Porpoises

Table 4.14 Significance of Ecological Impacts Associated with the Construction and Operation Activities of the Proposed Project Evaluated in accordance with EIAO-TM

Table 5.1 Evaluation of Fisheries Impacts in accordance to the Criteria described in Annex 9 of EIAO-TM

Table 6.1 Government Waste Disposal Facilities for Construction Waste

Table 6.2 HKSAR Government Charging System for Disposal of Dredged Sediment

Table 6.3 Marine Sediment Analytical Results

Table 6.4 Estimated Volumes of Sediments for each CMP

Table 7.1 Geophysical Survey Equipment

Table 7.2 Sonar Contact

Table 8.1 Calculations of Dose and Subsequent Incremental Carcinogenic Risk Levels

Table 8.2 Hazard Quotients for Populations of Concern

Table 9.1 Hong Kong Air Quality Objectives

Table 9.2 Identified Representative ASRs

Table 9.3 Concentrations of Air Pollutants Measured at HK Electric’s Cheung Chau AQMS in the Recent Three Years (2018-2020)

Table 9.4 Concentrations of Air Pollutants Measured at HK Electric’s Ap Lei Chau AQMS in the Recent Three Years (2018-2020)

Table 9.5 Background Air Pollutant Concentrations Predicted by PATH Model (v2.1) in 2024

Table 10.1 EIAO-TM Daytime Construction Noise Standards (Leq, 30 min dB(A))

Table 10.2 Area Sensitivity Ratings

Table 10.3 Acceptable Noise Levels for General Construction Works

Table 10.4 Acceptable Noise Levels for Operational Noise

Table 12.1 Summary of Environmental Assessment – Water Quality

Table 12.2 Summary of Environmental Assessment – Marine Ecology

Table 12.3 Summary of Environmental Assessment – Fisheries

Table 12.4 Summary of Environmental Assessment – Waste Management

Table 12.5 Summary of Environmental Assessment – Cultural Heritage

Table 12.6 Summary of Environmental Assessment – Hazard to Health

Table 12.7 Summary of Environmental Assessment – Air Quality

Table 12.8 Summary of Environmental Assessment – Noise

Table 12.9 Key Assessment Assumptions, Limitation of Assessment Methodologies and related Prior Agreement(s) with the Relevant Authorities