Highways Department                                                        路 政 署

Major Works Project Management Office                                           主要工程管理處

 

 

 

 

Widening of Tsuen Wan Road

and the Associated Junction Improvement Works

 

 

 

 

 

 

Environmental Impact Assessment Report

 

 

 

August 2023

 

 

 

 

 

 

Approved for Issue:

Steven Wong

MHKIQEP (PM0075), MHKIEIA, MHKIOA, MIOA

 

 

25 August 2023

 

 

 

 

 

 

AECOM ASIA COMPANY LIMITED

 

This report is prepared for HyD and is given for its sole benefit in relation to and pursuant to Agreement No. CE 61/2018 (HY) and may not be disclosed to, quoted to or relied upon by any person other than HyD without our prior written consent.

No person (other than HyD) into whose possession a copy of this report comes may rely on this report without our express written consent and HyD may not rely on it for any purpose other than as described above.

 

 

 

TABLE OF CONTENTS

 

1............. INTRODUCTION. 1-1

1.1              Project Background. 1-1

1.2           Designated Projects under Environmental Impact Assessment Ordinance. 1-2

1.3           Purpose of the EIA Study. 1-2

1.4           Objectives of this EIA Study. 1-2

1.5           Structure of the EIA Report 1-3

 

 

2............. project descriptions. 2-1

2.1              Purpose, Objective and Benefits of the Project 2-1

2.2           The Need of the Project 2-1

2.3           Location and Scope of the Project 2-1

2.4           Considerations of Alternative Options and Selection of Preferred Scheme. 2-2

2.5           Key Design Elements. 2-4

2.6           Consideration of Different Construction Methods for Viaduct 2-5

2.7           Construction Programme. 2-7

2.8           Concurrent Projects

  2-8

2.9           Public Concern. 2-10

 

 

3............. Air Quality Impact. 3-1

3.1              Introduction. 3-1

3.2           Environmental Legislation, Standards and Guidelines. 3-1

3.3           Description of Environment 3-2

3.4           Identification of Air Sensitive Receivers. 3-3

3.5           Identification of Environmental Impacts. 3-10

3.6           Assessment Methodology. 3-14

3.7           Prediction and Evaluation of Environmental Impacts. 3-21

3.8           Mitigation of Adverse Environmental Impacts. 3-37

3.9           Evaluation of Residual Impacts. 3-39

3.10         Environmental Monitoring and Audit 3-39

3.11         Conclusion. 3-39

 

 

4............. Noise Impact. 4-1

4.1              Introduction. 4-1

4.2           Environmental Legislation, Standards and Criteria. 4-2. 4-3

4.3           Noise Sensitive Receivers. 4-4

4.4           Identification of Environmental Impacts. 4-10

4.5           Assessment Methodology. 4-11

4.6           Prediction and Evaluation of Environmental Impacts. 4-14

4.7           Mitigation of Environmental Impacts. 4-22

4.8           Evaluation of Residual Impact 4-31

4.9           Environmental Monitoring and Audit 4-32

4.10         Conclusion. 4-32

 

 

5............. water quality Impact. 5-1

5.1              Introduction. 5-1

5.2              Environmental Legislation, Standards and Guidelines. 5-1

5.3              Description of Environment 5-6

5.4              Water Sensitive Receivers (WSRs) 5-9

5.5              Identification of Potential Impacts. 5-10

5.6              Assessment Methodology. 5-10

5.7              Water Quality Impact Assessment 5-11

5.8              Water Quality Mitigation Measures. 5-13

5.9              Cumulative Impact Assessment 5-17

5.10            Residual Water Quality Impacts. 5-17

5.11            Environmental Monitoring and Audit Requirements. 5-17

5.12            Conclusion. 5-18

 

 

6............. waste management implication. 6-1

6.1              Introduction. 6-1

6.2              Environmental Legislation, Standards and Criteria. 6-1

6.3              Description of the Environment 6-3

6.4              Identification of Waste Management Implications. 6-3

6.5              Assessment Methodologies. 6-4

6.6              Prediction and Evaluation of Wastes Implications. 6-4

6.7              Mitigation of Adverse Environmental Impacts. 6-8

6.8              Evaluation of Residual Impacts. 6-15

6.9              Environmental Monitoring and Audit Requirements. 6-15

6.10            Conclusion. 6-15

 

 

7............. land contamination. 7-1

7.1              Introduction. 7-1

7.2              Environmental Legislation, Standards and Criteria. 7-1

7.3              Assessment Methodology. 7-1

7.4              Description of the Environment 7-2

7.5              Identification of Potential Land Contamination Concern. 7-3

7.6              Prediction and Evaluation of Environmental Impacts. 7-18

7.7              Evaluation of Residual Impacts. 7-18

7.8              Environmental Monitoring and Audit Requirements. 7-18

7.9              Conclusion. 7-18

 

 

8............. landfill gas hazard. 8-1

8.1              Introduction. 8-1

8.2           Environmental Legislation, Standards and Guidelines. 8-1

8.3           Landfill Gas Hazard Assessment Criteria and Methodology. 8-2

8.4           Identification, Predication and Evaluation of Environmental Impact 8-7

8.5           Source Pathway Target Assessment 8-10

8.6           Recommended Precautionary Measures. 8-10

8.7           Conclusion. 8-13

 

 

9............. hazard to life review

. 9-1

9.1              Yau Kom Tau Water Treatment Works (YKTWTW) 9-1

9.2           Hazard to Life Review for OSCG Operation in YKTWTW.. 9-1

 

 

10........... CULTURAL HERITAGE. 10-1

10.1            Introduction. 10-1

10.2         Environmental Legislation, Standards and Criteria. 10-1

10.3         Assessment Methodologies. 10-2

10.4         Background of the Assessment Area. 10-3

10.5         Baseline Conditions. 10-7

10.6         Evaluation of Cultural Heritage Impacts. 10-7

10.7         Mitigation Measures. 10-8

10.8         Environmental Monitoring and Audit 10-8

10.9         Conclusion. 10-8

 

11........... Landscape and Visual Impact. 11-1

11.1            Introduction. 11-1

11.2            Environmental Legislation, Standards and Guidelines. 11-1

11.3            Assessment Area. 11-2

11.4            Assessment Methodology of Landscape and Visual Impact Assessment 11-2

11.5            Landscape Resources and Landscape Character Areas. 11-7

11.6            Individual Tree and Vegetation Survey. 11-15

11.7            Visual Envelopes and Visually Sensitivie Receivers. 11-16

11.8            Landscape Impact Assessment 11-19

11.9         Visual Impact Assessment 11-25

11.10         Landscape and Visual Mitigation Measures. 11-34

11.11         Residual Impact 11-39

11.12         Cumulative Impacts. 11-50

11.13         Environmental Monitoring and Audit 11-50

11.14         Conclustion. 11-50

 

 

12........... Environmental Monitoring and Audit Requirements. 12-1

12.1            Introduction. 12-1

12.2            Air Quality Impact 12-1

12.3            Noise Impact 12-1

12.4            Water Quality Impact 12-1

12.5            Waste Management Implications. 12-2

12.6            Land Contamination. 12-2

12.7            Landfill Gas Hazard. 12-2

12.8            Impact on Cultural Heritage. 12-3

12.9            Landscape and Visual Impact 12-3

 

 

13........... SUMMARY OF ENVIRONMENTAL OUTCOMES. 13-1

13.1            Overview. 13-1

13.2            Environmental Benefits of the Project 13-1

13.3            Incorporation of Environmentally Friendly Options. 13-1

13.4            Environmental Design Recommended. 13-2

13.5            Key Environmental Problems Avoided and Environmentally Sensitive Areas Protected. 13-2

13.6            Environmental Protection Measures Recommended. 13-3

13.7            Estimation of Population Protected. 13-6

 

 

14........... Conclusions. 14-1

14.1            Conclusion of EIA Study. 14-1

 

 

List of Tables

 

Table 2.1

Comparison of Different Construction Methods for Viaduct

Table 2.2

Summary of the Other Projects in the Vicinity of the Project Site

Table 2.3

Summary of Concerns and Follow Up Actions

Table 3.1

Hong Kong Air Quality Objectives

Table 3.2

Tunnel Air Quality Guidelines

Table 3.3

Average Concentrations of Pollutants in the Recent Five Years (Year 2018 – 2022) at Tsuen Wan EPD Air Quality Monitoring Station

Table 3.4

Background Air Pollutants in Year 2025 (Extracted from the PATH-v2.1)

Table 3.5

Representative Air Sensitive Receivers in the vicinity of the Project

Table 3.6

Summary of Surface Roughness Adopted in CALINE4 Model

Table 3.7

Predicted Cumulative Concentrations at Representative Air Sensitive Receivers under Without Project Scenario

Table 3.8

Predicted Cumulative Concentrations at Representative Air Sensitive Receivers under With Project (Without DNR) Scenario

Table 3.9

Predicted Cumulative Concentrations at Representative Air Sensitive Receivers under With Project (With DNR) Scenario

Table 3.10

Difference in Predicted Annual-averaged NO2 at Representative Air Sensitive Receivers under With Project (With DNR) Scenario and Without Project Scenario

Table 3.11

Summary of Incremental Air Quality Impact

Table 4.1

Area Sensitivity Ratings (ASRs)

Table 4.2

Acceptable Noise Levels under the Technical Memorandum on Noise from Construction Work other than Percussive Piling

Table 4.3

Representative Noise Sensitive Receivers

Table 4.4

Summary of Unmitigated Construction Noise Assessment Results at Representative NSRs (non-restricted hours)

Table 4.5

Summary of Unmitigated Construction Noise Assessment Results at Representative NSRs (restricted hours)

Table 4.6

Summary of Predicted Road Traffic Noise Assessment Results under Unmitigated Scenario (Year 2035) – without Slip Road C Option

Table 4.7

Summary of Mitigated Construction Noise Assessment Results at Representative NSRs (non-restricted hours)

Table 4.8

Summary of Mitigated Construction Noise Assessment Results at Representative NSRs (restricted hours)

Table 4.9

Extent and Locations of Proposed Noise Barriers, Semi-Enclosure and Full Enclosure

Table 4.10

Summary of Predicated Road Traffic Noise Assessment Results under Mitigated Scenario (Year 2035) without Slip Road C Option

Table 4.11

Number of residential dwellings/rooms benefited and protected under Mitigated Scenario (without Slip Road C Option)

Table 4.12

Estimated number of dwellings, classrooms and other NSRs exposed to exceedance (without Slip Road C Option)

Table 5.1

Summary of Water Quality Objectives for Western Buffer WCZ

Table 5.2

Summary of Water Quality Objectives for Victoria Harbour (Phase One) WCZ

Table 5.3

WSD’s Water Quality Criteria for Flushing Water at Sea Water Intakes

Table 5.4

Summary of Marine Water Quality of Monitoring Data Collected by EPD in 2021 for WM4

Table 5.5

Summary of Marine Water Quality of Monitoring Data Collected by EPD in 2021 for VM12, VM14 and VT8

Table 5.6

List of Marine WSRs

Table 5.7

List of Inland WSRs

Table 6.1

Estimated Quantities of C&D Materials during Construction Phase

Table 6.2

Tentative Transportation Routings for Waste Disposal During Construction Phase

Table 6.3

Summary of Estimated Waste Arising and Recommended Disposal

Table 7.1

Aerial Photographs Reviewed

Table 7.2

Summary of Chemical Waste Producers within the Project Area

Table 7.3

Summary of Dangerous Goods License Information

Table 7.4

Summary of Incident Records

Table 7.5

Summary of Potential Land Contamination Issues within the Project Area

Table 8.1

Classification of the Source

Table 8.2

Classification of Pathway

Table 8.3

Classification of Target

Table 8.4

Classification of Risk Category

Table 8.5

Summary of General Categorization of Risk

Table 8.6

Generic Protection Measures for Planning Stage Categorization

Table 8.7

Definition of Control Terms

Table 8.8

Gas Monitoring Data for GBD Landfill (July 2020 ~ June 2022)

Table 8.9

Overall Risk Categorization

Table 11.1

Relationship between Landscape Sensitivity and Magnitude of Change in Defining Impact Significance

Table 11.2

Relationship between VSRs’ Sensitivity and Magnitude of Change in Defining Impact Significance

Table 11.3

List of Landscape Resources (LRs) and their Sensitivity

Table 11.4

List of Landscape Character Area (LCAs) and their Sensitivity

Table 11.5

List of Visually Sensitive Receivers (VSRs) and their Sensitivity

Table 11.6

Magnitude of Landscape Impacts on LR during Construction and Operation

Table 11.7

Magnitude of Landscape Impacts on LCA during Construction and Operation

Table 11.8

Magnitude of Visual Impacts during Construction and Operation

Table 11.9

Landscape and Visual Mitigation Measures for Construction Phase

Table 11.10

Landscape and Visual Mitigation Measures for Operation Phase

Table 11.11

Significance of Landscape Impacts during Construction and Operation Phases

Table 11.12

Significance of Visual Impacts during Construction and Operation Phases

Table 13.1

Summary of Key Environmental Problems Avoided and Sensitive Areas Protected

Table 13.2

Key Recommended Mitigation Measures

Table 14.1

Summary of Key Environmental Outcomes and Benefits