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Proposed Interim Sewage Treatment Plant and Effluent Reuse Facility at Wo Shang Wai, Yuen Long

Environmental Impact Assessment

June 2018

Contents

1.2 Designated Projects under the EIA Ordinance

1.3 Purpose of the EIA Study

1.4 Objectives of the EIA Study

1.5 Scope of the EIA Study

1.5.1 Potential Hazard to Life

1.6 Structure of the EIA Report

2 Project Description

2.1 Introduction

2.2 Project Location and History

2.2.1 Project Location

2.2.2 Site History

2.3 Project Components

2.3.1 Effluent Treatment Process

2.3.2 Operation and Maintenance

2.3.3 Measures for Effluent Reuse to avoid Potential Health Impacts

2.4 Need of the Project

2.4.1 Environmental Benefits of the Project

2.5 Consideration of “Without Project” Alternative

2.6 Consideration of Alternative Siting and Layout

2.7 Consideration of Alternative Construction Method

2.8 Programme and Sequence of Works

2.9 Concurrent Projects

3 Air Quality Impact

3.1 Introduction

3.2 Environmental Legislation, Standards and Guidelines

3.2.1 Technical Memorandum on Environmental Impact Assessment Process

3.2.2 Air Pollution Control Ordinance

3.2.3 Air Pollution Control (Construction Dust) Regulation

3.2.4 Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation

3.3.1 Local Environment and Study Area Description

3.3.2 Background Air Quality

3.3.3 Key Pollutants of Concern

3.3.4 Air Sensitive Receivers

3.3.5 Cumulative Impacts

3.4 Air Quality Impact Assessment Methodology

3.4.1 Construction Phase

3.4.2 Operation Phase

3.5 Evaluation and Assessment of Air Quality Impacts

3.5.1 Construction Phase

3.5.2 Operation Phase

3.5.3 Decommissioning Phase

3.6 Mitigation Measures

3.6.1 Construction Phase

3.6.2 Operation Phase

3.7 Residual Impacts

3.7.1 Construction Phase

3.7.2 Operation Phase

3.8 Environmental Monitoring and Audit

3.8.1 Construction Phase

3.8.2 Operation Phase

3.9.1 Construction phase

3.9.2 Operation Phase

4.1 Introduction

4.2 Environmental Legislation, Standards and Guidelines

4.2.1 Construction Phase

4.2.2 Operation Phase

4.3 Assessment Area

4.4 Description of the Noise Environment

4.5 Noise Sensitive Receivers

4.6 Identification of Noise Sources

4.6.1 Construction Phase

4.6.2 Operation Phase

4.6.3 Decommissioning Phase

4.7 Assessment Methodology

4.7.1 Construction Noise

4.7.2 Operational Noise

4.8 Evaluation and Assessment of Noise Impact

4.8.1 Construction Phase

4.8.2 Operation Phase

4.9 Mitigation Measures

4.9.1 Construction Phase

4.9.2 Operation Phase

4.10 Residual Impacts

4.10.1 Construction Phase

4.10.2 Operation Phase

4.11 Environmental Monitoring and Audit

4.11.1 Construction Phase

4.11.2 Operation Phase

4.12 Conclusion

4.12.1 Construction Phase

4.12.2 Operation Phase

4.12.3 Decommissioning Phase

5 Water Quality Impact

5.1 Introduction

5.2 Environmental Legislation, Standards and Guidelines

5.2.1 Environmental Impact Assessment Ordinance

5.2.2 Water Pollution Control Ordinance

5.2.3 Technical Memorandum on Standards for Effluents Discharged into Drainage
and Sewerage Systems, Inland and Coastal Waters

5.2.4 Town Planning Board Guidelines No. 12C

5.2.5 Practice Note for Professional Persons on Construction Site Drainage

5.3 Assessment Area, Water Sensitive Receivers and Background Conditions

5.3.1 Assessment Area and Water Sensitive Receivers

5.3.2 Background Water Quality Conditions

5.4 Assessment Methodology

5.5 Identification and Evaluation of Water Quality Impacts

5.5.1 Construction Phase

5.5.2 Operation Phase

5.5.3 Decommissioning Phase

5.6 Mitigation of Adverse Water Quality Impacts

5.6.1 Construction Phase

5.6.2 Operation Phase

5.6.3 Decommissioning Phase

5.7 Evaluation of Cumulative and Residual Impact

5.8 Environmental Monitoring and Audit

6 Waste Management Implications

6.1 Introduction

6.2 Environmental Legislation, Standards and Guidelines

6.2.1 Environmental Impact Assessment Ordinance

6.2.2 Waste Disposal Ordinance

6.2.3 Waste Disposal (Chemical Waste) (General) Regulation

6.2.4 Waste Disposal (Charges for Disposal of Construction Waste) Regulation

6.2.5 Dumping at Sea Ordinance

6.2.6 Public Cleansing and Prevention of Nuisances Regulation

6.2.7 Land (Miscellaneous Provisions) Ordinance

6.3 Assessment Methodology

6.3.1 Analysis of Activities and Waste Generation

6.3.2 Development of Proposals for Waste Management

6.3.3 Excavation and Dumping of Sediment

6.4 Identification, Prediction and Evaluation of Environmental Impact

6.4.1 Potential Land Contamination

6.4.2 Construction Phase

6.4.3 Operation Phase

6.5 Mitigation of Adverse Environmental Impact

6.5.1 Construction Phase

6.5.2 Operation Phase

6.6 Evaluation of Residual Impact

6.7 Environmental Monitoring and Audit

6.8.1 Construction Phase

6.8.2 Operation Phase

7 Ecological Impact (Terrestrial and Aquatic)

7.1 Introduction

7.2 Environmental Legislation, Standards and Guidelines

7.3 Study Area and Methodology

7.3.1 Study Area

7.3.2 Assessment Methodology

7.3.3 Literature Review

7.4 Baseline Condition and Ecological Sensitive Receivers

7.4.1 General Description of the Project Site and Study Area

7.4.2 Recognized Sites of Conservation Interest

7.4.3 Habitat and Vegetation

7.4.6 Amphibian and Reptile

7.4.7 Butterfly

7.4.8 Dragonfly

7.4.9 Freshwater fish and aquatic fauna

7.5 Evaluation of Ecological Importance of Habitats and Species

7.5.1 Evaluation of Habitats

7.5.2 Evaluation of Species of Conservation Interest

7.6 Identification and Evaluation of Ecological Impacts

7.6.1 Construction and Decommissioning Phases

7.6.2 Operation Phase

7.6.3 Cumulative Impact

7.7 Precautionary and Mitigation Measures

7.7.1 Precautionary Measures for Minimization of Indirect Disturbance on Ecology

7.8 Evaluation of Residual Ecological Impact

7.9 Environmental Monitoring and Audit Requirements

7.11 References

8 Landscape and Visual Impact

8.1 Introduction

8.2 Relevant Legislation, Standards and Guidelines

8.3 Assessment Methodology

8.3.1 Study Area

8.3.2 Review of Planning and Development Control Framework

8.3.3 Landscape Baseline Survey

8.3.4 Landscape Impact Assessment

8.3.5 Broad Brush Tree Survey

8.3.6 Impact Assessment on Trees

8.3.7 Visual Baseline Survey

8.3.8 Visual Impact Assessment

8.3.9 Recommended Mitigation Measures

8.3.10 Assessment of Residual Impact

8.4 Baseline Survey Findings

8.4.1 Review of Development Control Framework

8.4.2 Landscape Resources

8.4.3 Landscape Character Types

8.4.4 Landscape Character Areas

8.4.5 Zone of Visual Influence

8.4.6 Visually Sensitive Receivers

8.4.7 Vantage Points

8.5 Tree Survey Findings

8.5.1 Existing Tree Groups

8.5.2 Potential Impact on Trees

8.6 Sources of Potential Impact

8.6.1 Sources of Impact during Construction

8.6.2 Sources of Impact during Operation

8.6.3 Sources of Impact during Decommissioning

8.7 Magnitude of Change

8.7.1 Magnitude of Change on Landscape Resources

8.7.2 Magnitude of Change on Landscape Character Areas

8.7.3 Magnitude of Change on Visually Sensitive Receivers

8.8 Assessment of Potential Impact without Mitigation

8.8.1 Potential Impact on Landscape Resources without Mitigation

8.8.2 Potential Impact on Landscape Character Areas without Mitigation

8.8.3 Potential Impact on Visually Sensitive Receivers without Mitigation

8.9 Recommended Precautionary / Enhancement / Mitigation Measures

8.9.1 Recommended Construction Phase Precautionary / Enhancement Measures

8.9.2 Recommended Operation Phase Mitigation Measures

8.9.3 Recommended Decommissioning Phase Mitigation Measures

8.10 Assessment of Potential Impact with Mitigation

8.10.1 Photomontages

8.10.2 Potential Impact on Landscape Resources with Mitigation

8.10.3 Potential Impact on Landscape Character Areas with Mitigation

8.10.4 Potential Impact on Visually Sensitive Receivers with Mitigation

8.11 Assessment of Cumulative Impact

8.11.1 Potential Concurrent Project

8.11.2 Potential Cumulative Impact

8.12.1 Review of Planning and Development Control Framework

8.12.2 Potential Impact on Trees

8.12.3 Residual Landscape Impact

8.12.4 Residual Visual Impact

8.13 Conclusion

8.13.1 Overall Landscape Impact

8.13.2 Overall Visual Impact

8.13.3 Overall Acceptability

9.2 Summary of Environmental Outcomes

9.2.1 Estimated Population Protected from Various Environmental Impacts

9.2.2 Environmentally Sensitive Areas Protected

9.2.3 Environmental Designs Recommended

9.2.4 Key Environmental Problems Avoided

9.2.5 Compensation Areas Included

9.2.6 Main Concerns of General Public

9.3 Air Quality Impact

9.3.1 Construction Phase

9.3.2 Operation Phase

9.4 Noise Impact

9.4.1 Construction Phase

9.4.2 Operational Phase

9.5 Water Quality Impact

9.5.1 Construction Phase

9.5.2 Operational Phase

9.6 Waste Management Implications

9.6.1 Construction Phase

9.6.2 Operation Phase

9.7 Ecological Impact

9.7.1 Construction Phase

9.7.2 Operation Phase

9.8 Landscape and Visual Impact

9.8.1 Overall Landscape Impact

9.8.2 Overall Visual Impact

9.8.3 Overall Acceptability

9.9 Summary of Environmental Impacts

9.10 Key Assessment Assumptions, Limitations of Assessment Methodologies and related Prior Agreement

10 Environmental Monitoring and Audit

10.2 Air Quality Impact

10.3 Noise Impact

10.4 Water Quality Impact

10.5 Waste Management Implications

10.6 Ecological Impact

10.7 Landscape and Visual Impact

11 Implementation Schedule

Tables

Table 2.1: WSD Reuse Water Quality Standard for Non-Potable Uses

Table 2.2: Summary of Hong Kong Project Utilizing Reclaimed Water for Non-Potable Use

Table 2.3: Summary of Alternative Siting and Layout of the Project

Table 3.1: Air Quality Objectives

Table 3.2: Historical Air Quality at the Project Area

Table 3.3: Future Background air quality from PATH-2016 for year 2020

Table 3.4: Location of Representative Air Sensitive Receivers

Table 3.5: Summary of Concurrent Projects

Table 4.1: Noise Standards for Daytime Construction Activities

Table 4.2: Area Sensitivity Rating

Table 4.3: Acceptable Noise Level for Fixed Noise Sources

Table 4.4: Noise Criteria for the Planned Fixed Noise Sources

Table 4.5: Representative Noise Sensitive Receivers for Construction and Operation Phases

Table 4.6: Maximum Predicted Cumulative Construction Noise Levels at Representative NSRs

Table 4.7: Maximum Allowable SWL and Predicted Fixed Plant Noise Level

Table 5.1: Water Quality Objectives for Deep Bay WCZ

Table 5.2: Key Water Quality Objectives for inland waters in Yuen Long & Kam Tin (Lower)
Subzone of Deep Bay Water Control Zones

Table 5.3: Standards for effluents discharged into Group C inland waters (All units in mg/L unless otherwise stated; all figures are upper limits unless otherwise indicated)

Table 5.4: Summary of River Water Quality at Nearby Fairview Park Nullah in the Deep Bay Water Control Zones between 2011 and 2015 (Source: River Water Quality in Hong Kong in 2011 – 2015 (EPD))

Table 5.5: Summary of Baseline Water Quality Monitoring Results of the Planned WSW Development (2009)

Table 5.6: Summary of Impact Water Quality Monitoring Results of the Planned WSW Development (2015)

Table 5.7: WSD Reuse Water Quality Standard for Non-Potable Uses

Table 6.1: Estimation of Sediment Quantities for Each Category

Table 6.2: Criteria for Reuse of Treated Sediment

Table 6.3: Summary of Waste Arising during Construction Phase

Table 6.4: Estimation of General Refuse Generation during Operation Phase

Table 7.1: Habitats Present in the Project Site

Table 7.2: Habitats Present in the Study Area (excluding the Project Site)

Table 7.3: Summary Table for Avifauna Species of Conservation Interest Recorded in the Study Area

Table 7.4: Summary Table for Fish Species Recorded in Major Habitats within Study Area

Table 7.5: Ecological Evaluation of Wetland Restoration Area

Table 7.6: Ecological Evaluation of Fishpond

Table 7.7: Ecological Evaluation of Abandoned Fishpond

Table 7.8: Ecological Evaluation of Drainage Channel/Ditch

Table 7.9: Ecological Evaluation of Marsh/Reedbed

Table 7.10: Ecological Evaluation of Secondary Woodland

Table 7.11: Ecological Evaluation of Plantation

Table 7.12: Ecological Evaluation of Developed / Disturbed Area

Table 7.13: Ecological Evaluation of Fauna Species of Conservation Interest recorded within the Study Area from Literature Review

Table 7.14: Evaluation of Indirect Ecological Impact on Habitats

Table 7.15: Evaluation of Indirect Ecological Impact on Egretries

Table 7.16: Evaluation of Indirect Ecological Impact on Fauna Species of Conservation Interest

Table 7.17: Evaluation of Disturbance Impact during Operation Phase

Table 7.18: Evaluation of Indirect Ecological Impact to Aquatic Habitats during Operation Phase

Table 8.1: Sensitivity and Magnitude of Change on the Degree of Impact Significance

Table 8.2: Review of Existing Planning and Development Control Framework

Table 8.3: Sensitivity of Landscape Resources

Table 8.4: Descriptions on Landscape Character Types within the Study Area

Table 8.5: Sensitivity of Landscape Character Areas

Table 8.6: Sensitivity of Visually Sensitive Receivers

Table 8.7: Estimated Number of Trees in Tree Groups

Table 8.8: Magnitude of Change on Landscape Resources

Table 8.9: Magnitude of Change on Landscape Character Areas

Table 8.10: Magnitude of Change on Visually Sensitive Receivers

Table 8.11: Potential Impact on Landscape Resources without Mitigation

Table 8.12: Potential Impact on Landscape Character Areas without Mitigation

Table 8.13: Potential Impact on Visually Sensitive Receivers without Mitigation

Table 8.14: Recommended Construction Phase Precautionary / Enhancement Measures

Table 8.15: Recommended Operation Phase Mitigation Measures

Table 8.16: Summary of Impact Assessment on Landscape Resources

Table 8.17: Summary of Impact Assessment on Landscape Character Areas

Table 8.18: Summary of Impact Assessment on Visually Sensitive Receivers

Table 9.1: Summary of Environmental Impacts

Table 9.2: Key Assessment Assumptions, Limitations of Assessment Methodologies and Prior Agreements

Table 11.1 Implementation Schedule 11-2

Figures

Figure 2.1a Project Location Options

Figure 2.1b Project Location

Figure 2.2 Historical Aerial Photo

Figure 2.3 Proposed Effluent Reuse Facility

Figure 2.4 Process Flow Diagram of Interim On-site STP

Figure 3.1 Location of Representative Air Sensitive Receivers and Air Quality Monitoring Stations

Figure 4.1 Location of Representative Noise Sensitive Receivers (Construction Phase)

Figure 4.2 Location of Representative Noise Sensitive Receivers (Operation Phase)

Figure 4.3 Photos of Existing Representative Noise Sensitive Receivers

Figure 4.4 Temporary Noise Barrier and Site Hoarding Locations for Construction Phase

Figure 5.1 Location of Representative Water Sensitive Receivers and Existing Monitoring Locations

Figure 5.2 Proposed Onsite Sewerage Network

Figure 6.1 Borehole Locations

Figure 7.1 Habitat Map

Figure 8.1 Landscape Study Area

Figure 8.2 Aerial View of Landscape Study Area

Figure 8.3 Zone of Visual Influence and Visually Sensitive Receivers

Figure 8.4 Zoning in Outline Zoning Plan within the Landscape Study Area

Figure 8.5 Location Plan of Landscape Resources

Figure 8.6a Representative Photographs of Landscape Resources (Sheet 1 of 4)

Figure 8.6b Representative Photographs of Landscape Resources (Sheet 2 of 4)

Figure 8.6c Representative Photographs of Landscape Resources (Sheet 3 of 4)

Figure 8.6d Representative Photographs of Landscape Resources (Sheet 4 of 4)

Figure 8.7 Location Plan of Landscape Character Types

Figure 8.8 Location Plan of Landscape Character Areas

Figure 8.9a Representative Photographs of Landscape Charcater Areas (Sheet 1 of 2)

Figure 8.9b Representative Photographs of Landscape Charcater Areas (Sheet 2 of 2)

Figure 8.10 Anticipated View from Selected Vantage Point without the Project

Figure 8.11 Preliminary Landscape Master Plan

Figure 8.12 Photomontages for Selected Vantage Point

Figure 8.13 Assessment of Landscape Impact

Figure 8.14 Assessment of Visual Impact

Appendices

Appendix 2.1 Approved Sewerage Impact Assessment

Appendix 4.1 Letter from MTR Corporation

Appendix 4.2 Construction Noise Impact Assessment in Approved WSW VEP (ERR for Change in Master Layout Plan) (Application No. VEP-538/2017)
Appendix 4.3 Fixed Noise Sources Impact Assessment

Appendix 5.1 Calculations for Sewage Loads
Appendix 5.2 Calculations for Reclaimed Water Demand

Appendix 6.1        Remediation Report
Appendix 6.2        Site Photos of STP Project Area
Appendix 6.3        Approval Letter of SSTP from EPD
Appendix 6.4        Chemical Testing Results
Appendix 6.5        Biological Testing Results
Appendix 6.6        Approval Letter of SQR from EPD

Appendix 7.1 Plates – Representative Photographs of Habitats

Appendix 7.2 Bird Species Recorded in Major Habitats within the Project Site and the Study Area

Appendix 7.3 Mammal Species Recorded in Major Habitats within the Project Site and the Study Area

Appendix 7.4 Amphibian and Reptile Species Recorded in Major Habitats within the Project Site and the Study Area

Appendix 7.5 Butterfly Species Recorded in Major Habitats within the Project Site and the Study Area

Appendix 7.6 Dragonfly Species Recorded in Major Habitats within the Project Site and the Study Area

Appendix 8.1 Tree Assessment Schedule of Tree Groups within the Landscape Study Area