Figure 1.1	Locations of Key Construction Activities
Figure 2.1	Locations of Air and Noise Monitoring Stations and Chek Lap Kok Wind Station
Figure 2.2a	Water Quality Monitoring Stations (from 25 Jan 2022 to 31 Oct 2023)
Figure 2.2b	Post-construction Phase Water Quality Monitoring Stations (from 14 Nov 2023 to 9 Dec 2023)
Figure 2.3	Overall Sampling Grids for the Newly Reclaimed Area
Figure 2.4	The Backfilling Locations for Treated Marine Sediment
Figure 2.5	Vessel based Dolphin Monitoring Transects in Construction, Post-Construction and Operation Phases
Figure 2.6	Land based Dolphin Monitoring in Baseline and Construction Phases
Figure 2.7	Location for Autonomous Passive Acoustic Monitoring

Appendices

Appendix A	Contract Description
Appendix B	Project Organization Chart
Appendix C	Environmental Mitigation Implementation Schedule (EMIS) for Construction Phase
Appendix D	Monitoring Results
Appendix E	Sampling Results for Marine Sediment Samples
Appendix F	Chinese White Dolphin Monitoring Results
Appendix G	Summary of Environmental Complaints and Cumulative Statistics on Exceedances, Notification of Summons, and Prosecution
Appendix H	Tree Schedule

Abbreviations

3RS	Three-Runway System
AAHK	Airport Authority Hong Kong
AECOM	AECOM Asia Company Limited
ABWF	Architectural, Builder's Work and Finishing Works
ACE	Advisory Council on the Environment
AFCD	Agriculture, Fisheries and Conservation Department
AIS	Automatic Information System
ANI	Encounter Rate of Number of Dolphins
APM	Automated People Mover
AW	Airport West
BHS	Baggage Handling System
C	Control
CAP	Contamination Assessment Plan
CAR	Contamination Assessment Report
CDS	Conventional Distance Sampling
CLGs	Community Liaison Groups
COVID	Coronavirus Disease
CTP	Coral Translocation Plan
CWD	Chinese White Dolphin
CV	Coefficient of Variation
DCM	Deep Cement Mixing
DEZ	Dolphin Exclusion Zone
DO	Dissolved Oxygen
DPD	Detection Positive Days
DPM	Detection Positive Minutes
DPSE	Number of Dolphins per 100 Units of Survey Effort
EAR	Ecological Acoustic Recorder
EIA	Environmental Impact Assessment
EM&A	Environmental Monitoring & Audit
EP	Environmental Permit
EPD	Environmental Protection Department
EVT	Eastern Vehicular Tunnel
ET	Environmental Team
FCZ	Fish Culture Zone
HDD	Horizontal Directional Drilling
HKBCF	Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities
HKIA	Hong Kong International Airport
HOKLAS	The Hong Kong Laboratory Accreditation Scheme
HSF	High Speed Ferry
HZMB	Hong-Kong-Zhuhai-Macao Bridge
I-2RS	Interim Two Runway System
IEC	Independent Environmental Checker
IM	Impact Station
LKC	Lung Kwu Chau
MCDS	Multiple Covariate Distance Sampling
MTCC	Marine Traffic Control Centre
MMHK	Mott MacDonald Hong Kong Limited
MMWP	Marine Mammal Watching Plan
MSS	Maritime Surveillance System
MTRMP-CAV	Marine Travel Routes and Management Plan for Construction and Associated Vessel
NEL	Northeast Lantau
NWL	Northwest Lantau
PAM	Passive Acoustic Monitoring
PM	Partial Mortality
PVD	Prefabricated Vertical Drain
RBRGs	Risk Based Remediation Goals
SC	Sha Chau
SCLKCMP	Sha Chau and Lung Kwu Chau Marine Park
SCZ	Speed Control Zone
SPSE	Number of On-effort Sightings per 100 Units of Survey Effort
SPS-1	Sewage Pumping Station 1
SR	Sensitive Receiver
SS	Suspended Solids
STG	Encounter Rate of Number of Dolphin Sightings
SWL	Southwest Lantau
The Project	The Expansion of Hong Kong International Airport into a Three-Runway System
The SkyPier Plan	Marine Travel Routes and Management Plan for High Speed Ferries of SkyPier
T2	Terminal 2
T2C	Terminal 2 Concourse
TCLP	Toxicity Characteristics Leaching Procedure
TCSPS	Tung Chung Sewage Pumping Station
TSP	Total Suspended Particulates
UCS	Unconfined Compressive Strength
WL	West Lantau
WMP	Waste Management Plan
WVT	Western Vehicular Tunnel

Executive summary

The “Expansion of Hong Kong International Airport into a Three-Runway System” (the Project) serves to meet the future air traffic demands at Hong Kong International Airport (HKIA). On 7 November 2014, the Environmental Impact Assessment (EIA) Report (Register No.: AEIAR-185/2014) for the Project was approved and an Environmental Permit (EP) (Permit No.: EP-489/2014) was issued for the construction and operation of the Project.

This is the 8^th Construction Phase Annual EM&A Report for the Project which summarizes the monitoring results and audit findings of the EM&A programme during the reporting period from 1 January 2023 to 31 December 2023.

During the reporting period, the project is in the Interim Two Runway System (I-2RS) stage, in which the new North Runway and the associated taxiway and facilities were in operation together with the South Runway and existing airport facilities, with the Centre Runway closed down for modification works.

Key Activities in the Reporting Period

Key activities of the Project carried out in the reporting period were related to the following contracts:

Reclamation Works:

Contract 3206 Main Reclamation Works

● Armour rock laying and temporary platform construction; and

● Filling materials delivery & backfilling.

Airfield Works:

Contract 3302 Eastern Vehicular Tunnel Advance Works

● Tunnel construction and defect fixing;

● Pipe, stormwater drainage diversion and underground utilities works; and

● Stockpiling and backfilling works.

Contract 3305 Airfield Ground Lighting System

● Enhanced vehicular warning light hardware installation;

● Rectification work for airfield ground lighting system; and

● Cable containment & power supply system installation.

Contract 3306 Observation Facility Control System Supporting Interim 2RS and 3RS

● Equipment installation; and

● Structured cabling.

Contract 3307 Fire Training Facility

● Architectural, builder’s work and finishing works;

● Drainage and utilities works;

● Building construction; and

● Pavement work.

Contract 3308 Foreign Object Debris Detection System

● Rectification work for handover sensor system;

● Construction of foundation; and

● Tower modification works.

Contract 3310 North Runway Modification Works

● Architectural, builder’s work and finishing works;

● Land-based ground improvement works (Transition layer and backfilling);

● Excavation, lateral support, installation of pipe pile and pilings;

● Seawall, box culvert construction and rock armour laying;

● Construction of vehicular tunnel, walls, slabs and backfilling;

● Jet grouting and pavement works for runway; and

● Aviation fuel pipe and construction of stormwater drainage.

Terminal 2 Concourse and Apron Works:

Contract 3403 New Integrated Airport Centres Building and Civil Works

● Builder’s work for cable conduit and architectural, builder’s work and finishing works;

● Trench backfilling and demolition of antenna tower;

● Mechanical ventilation, air-conditioning, fire services and electrical works; and

● Roofing installation of covered walkway.

Contract 3404 Integrated Airport Control System

● Cable laying works and system maintenance.

Contract 3405 Three Runway Concourse Foundation and Substructure Works

● Bored piling, excavation and structure works;

● Setup of temporary drainage system;

● Marine sediment treatment works; and

● Road formation, tunnel concreting & backfilling.

Contract 3408 Third Runway Concourse and Apron Works

● Reinforced concrete, building services and architectural, builder’s work and finishing works;

● Excavation, cable laying, utilities and fuel pipe installation;

● Erection works for concrete batching plant; and

● Marine sediment treatment works.

Terminal 2 Expansion:

Contract 3508 Terminal 2 Expansion Works

● Excavation and footing construction;

● Viaduct pier and temporary road construction;

● Bridge demolition and hoarding erection;

● Drainage construction and crossroad duct laying;

● Roof, deck, beams and columns construction;

● Pump, electrical stations works; and

● Electrical and mechanical works and architectural, builder’s work and finishing works.

Automated People Mover and Baggage Handling System:

Contract 3601 New Automated People Mover System (TRC Line)

● Guidebeam installation.

Contract 3602 Existing APM System Modification Works

● Concrete plinth construction and defect rectification works; and

● Erection and fixing of power rail.

Contract 3603 3RS Baggage Handling System

● BHS and steel works installation.

Airport Support Infrastructure:

Contract 3801 APM and BHS Tunnels on Existing Airport Island

● Hoarding, formworks erection and excavation;

● Duct installation, rebar fixing and retaining wall construction;

● Casted walkway structure, concreting, coring works at bulkhead wall and pipe pile trimming;

● Installation of steel decking formworks, backfilling and dismantling;

● Drainage and road base works; and

● Castle cable trench, gas main pipe laying and utilities installation works.

Contract 3802 APM and BHS Tunnels and Related Works

● Excavation and lateral supports;

● APM & BHS Tunnel superstructure and box culvert construction;

● Demolition works; and

● Electrical and mechanical works and architectural, builder’s work and finishing works.

Contract 3804 East and Landside Fire Stations

● Site setup formation and ground investigation;

● Bored pile, concreting, excavation, pile cap construction and underground utilities works;

● Interface coring works for complete bored pile;

● Precast erection; and

● Raft foundation and superstructure.

Contract 3805 New Airport District Police Operational Base

● Ground Investigation works; and

● Construction of temporary working platform and bored pile.

Construction Support:

Contract 3721 Construction Support Infrastructure Works

● Additional and outstanding works of sewage manholes;

● Maintenance of temporary sewage pump and control panel;

● Watermain connection and laying of road works;

● Sewage phasing works for fire training facility; and

● Provision of backup services.

Contract 3722 Western Support Area – Construction Support Facilities

● Operation of Western Support Area sewage treatment plant.

Contract 3723 Eastern Support Area – Construction Support Facilities

● Operation of Eastern Support Area sewage treatment plant.

Contract 3901A Concrete Batching Facility

● Operation of concrete batching plant, and material conveyor belt.

Contract 3901B Concrete Batching Facility

● Operation of concrete batching plant and material conveyor belt.

Contract 3908 Quay Management Services

● Provision of services of site management and logistic control of 3RS quays; and

● Provision of flat top barge and vehicle delivery services between the launching point in Hong Kong and 3RS quays.

Contract 3913 Asphalt Batching Plant

● Operation of asphalt batching plant.

Utilities:

132kV Cable

● Cable trenching, draw pit opening, cable laying and duct installation;

● Cold milling and cable duct mandrill test; and

● Backfilling and resurfacing.

EM&A Activities Conducted in the Reporting Period

The EM&A programme was undertaken in accordance with the Manual. Summary of monitoring activities during this reporting period is presented as below:

Monitoring/ Audit Activities	Number of Sessions
Air Quality Monitoring	378
Noise Monitoring	206
General Impact Water Quality Monitoring	128
Post-construction Phase Water Quality Monitoring	12
Vessel line-transect Surveys for Chinese White Dolphin (CWD) Monitoring	24
Land-based Theodolite Tracking Survey Effort for CWD Monitoring	24

Environmental auditing works, including weekly site inspections of construction works conducted by the ET and bi-weekly site inspections conducted by the Independent Environmental Checker (IEC), audit of SkyPier High Speed Ferries (HSF), audit of construction and associated vessels, and audit of implementation of Marine Mammal Watching Plan (MMWP) and Dolphin Exclusion Zone (DEZ) Plan, were conducted in the reporting period. Based on the information including ET’s observations, records of Maritime Surveillance System (MSS), and contractors’ site records, it is noted that the environmental pollution control and mitigation measures were properly implemented and the construction activities of the Project in the reporting period did not introduce adverse impact to the environment.

The annual sewage flow monitoring has been started since June 2021 and completed in December 2022. As the purpose of the sewage flow monitoring is to inform the timing of commencement of planning for the sewer upgrading works, and considering that AAHK has initiated to start planning its construction, the annual monitoring was completed in 2022. The daily average flows data can be referred to the previous Annual EM&A Report No.7.

In accordance with Section 6.2.1.2 of the Manual, it was recommended to start routine monitoring of hydrogen sulphide (H₂S) levels for the sewerage system of 3RS upon commencement of operation of the project. During the reporting period, the H₂S monitoring proposal was submitted to EPD in April 2023 and accepted by EPD in June 2023.

Summary Findings of the EM&A Programme

The monitoring works for construction dust, construction noise, general impact water quality, post-construction phase water quality, construction waste, landscape & visual, and CWD were conducted during the reporting period in accordance with the Manual.

Monitoring results of construction dust, construction noise, construction waste and CWD did not trigger the corresponding Action and Limit Levels in the reporting period. No non-conformity was recorded for landscape & visual monitoring in the reporting period.

The general impact water quality monitoring results for all parameters, except dissolved oxygen (DO) and suspended solid (SS) obtained during the reporting period were within the corresponding Action and Limit Levels stipulated in the EM&A programme. Relevant investigation and follow-up actions were conducted according to the EM&A programme if the corresponding Action and Limit Levels were triggered. For dissolved oxygen (DO) and suspended solids (SS), some of the monitoring results triggered the relevant Action or Limit Levels, and corresponding investigations were conducted accordingly. The investigation findings concluded that all cases were not related to the Project. To conclude, the construction activities in the monitoring period did not introduce adverse impact to all water quality sensitive receivers.

The construction phase CWD impact monitoring did not stop together with the construction phase water quality impact monitoring. The construction phase CWD monitoring was continued until the end of December 2023 to collect a full-year set of monitoring data to facilitate the evaluation of CWD abundance on an annual basis. This arrangement was agreed upon by Agriculture, Fisheries and Conservation Department (AFCD) and EPD in December 2023. A total of around 5384.9 km survey effort was conducted for the vessel line-transect monitoring for CWDs during the 12-month monitoring period. A total of 160 groups of 542 CWDs were sighted in NWL, AW, WL and SWL survey areas. No CWDs were recorded in the NEL survey area. The combined encounter rates by number of dolphin sightings and by number of dolphins were 3.06 and 10.35 respectively. No triggering of Action and Limit Levels for encounter rates were recorded during the construction phase during 2023. Overall abundance of CWD in Hong Kong western waters was estimated at 40 dolphins in 2023 from line-transect analysis. CWD occurrence from land-based surveys around Lung Kwu Chau was only recorded during winter and summer seasons. Waters off Lung Kwu Chau continue to be habitat used primarily for travelling and foraging. Passive acoustic monitoring provides evidence that dolphins continued using the area around south of Sha Chau in 2023, especially in winter, and then primarily at night. A post-construction phase CWD monitoring includes vessels line-transect survey would be carried out for 12 months. The post-construction phase CWD monitoring would be commenced in January 2024.

Summary Table

The Key findings of the EM&A programme during the reporting period are summarised as below:

	Yes	No	Details	Analysis / Recommendation / Remedial Actions
Breach of Limit Level^		√	No exceedance of project-related Limit Level was recorded.	Nil
Breach of Action Level^		√	No exceedance of project-related Limit Level was record.	Nil.
Complaints Received	√		Twelve complaints were received in 2023: 9 Jun, 4 Oct, 9 Oct, 16 Oct, 20 Oct, 30 Oct, 21 Nov (3 complaints), 27 Nov, 12 Dec & 18 Dec	The complaint investigations were carried out in accordance with the Complaint Management Plan. Details are presented in S3.2.1.
Notification of any summons and status of prosecutions		√	No notification of summons nor prosecution was received.	Nil
Changes that affect the EM&A		√	There was no change to the construction works that may affect the EM&A.	Nil

Remarks: ^ Only triggering of Action or Limit Level found related to Project works is counted as Breach of Action or Limit Level.

In accordance with Condition 2.6 of EP, AAHK assisted AFCD in taking forward the statutory procedures for the designation of the North Lantau Marine Park (NLMP). A gazette notice regarding the approved map was published by the Government on 29 September 2023 with a Draft Designation Order and a relevant Executive Council paper was prepared. The NLMP will come into effect on 1 November 2024 and shall tie in with the commissioning of the 3RS.

1 Introduction

1.1 Background

On 7 November 2014, the Environmental Impact Assessment (EIA) Report (Register No.: AEIAR-185/2014) for the “Expansion of Hong Kong International Airport into a Three-Runway System” (the Project) was approved and an Environmental Permit (EP) (Permit No.: EP-489/2014) was issued for the construction and operation of the Project.

Airport Authority Hong Kong (AAHK) commissioned Mott MacDonald Hong Kong Limited (MMHK) to undertake the role of Environmental Team (ET) for carrying out the Environmental Monitoring & Audit (EM&A) works during the construction phase of the Project in accordance with the Manual [1] submitted under EP Condition 3.1. AECOM Asia Company Limited (AECOM) was employed by AAHK as the Independent Environmental Checker (IEC) for the Project.

The Project covers the expansion of the existing airport into a three-runway system (3RS) with key project components comprising land formation of about 650 hectares and all associated facilities and infrastructure including taxiways, aprons, aircraft stands, a passenger concourse, an expanded Terminal 2, all related airside and landside works and associated ancillary and supporting facilities. The existing submarine aviation fuel pipelines and submarine power cables also require diversion as part of the works.

Construction of the Project is to proceed in the general order of diversion of the submarine aviation fuel pipelines, diversion of the submarine power cables, land formation, and construction of infrastructure, followed by construction of superstructures.

The summary of construction works programme can be referred to the corresponding Monthly EM&A Reports. Description of relevant contracts in the reporting period is presented in Appendix A.

1.2 Scope of this Report

This is the 8^th Construction Phase Annual EM&A Report for the Project which summarizes the key findings of the EM&A programme during the reporting period from 1 January 2023 to 31 December 2023.

1.3 Project Organization

The Project’s organization structure and the contact details of the key personnel are provided in Appendix B and Table 1.1 respectively.

Table 1.1: Contact Information of Key Personnel

Party	Position	Name	Telephone
Project Manager’s Representative (Airport Authority Hong Kong)	Principal Manager, Environmental Compliance, Sustainability	Lawrence Tsui	2183 2734
Environmental Team (ET) (Mott MacDonald Hong Kong Limited)	Environmental Team Leader	Terence Kong	2828 5919
	Deputy Environmental Team Leader	Heidi Yu	2828 5704
	Deputy Environmental Team Leader	Ken Wong	2828 5817
Independent Environmental Checker (IEC) (AECOM Asia Company Limited)	Independent Environmental Checker	Roy Man	3729 0380
	Deputy Independent Environmental Checker	Jackel Law	3856 5312

Reclamation Works:

Party	Position	Name	Telephone
Contract 3206 Main Reclamation Works (ZHEC-CCCC-CDC Joint Venture)	Project Manager	Alan Mong	3763 1352
Environmental Officer	Zhang Bin Wang	3763 1451

Party

Position

Name

Telephone

Contract 3206 Main Reclamation Works

(ZHEC-CCCC-CDC Joint Venture)

Project Manager

Alan Mong

3763 1352

Environmental Officer

Zhang Bin Wang

3763 1451

Airfield Works:

Party	Position	Name	Telephone
Contract 3302 Eastern Vehicular Tunnel Advance Works (China Road and Bridge Corporation)	Project Manager	Dickey Yau	5699 4503
	Environmental Officer	Dennis Ho	5645 0563
Contract 3305 Airfield Ground Lighting System (ADB Safegate Hong Kong Limited)	Project Manager	Allam Al-Turk	2944 9725
	Environmental Officer	Ivan Ting	9222 9490
Contract 3306 Observation Facility Control System Supporting Interim 2RS and 3RS (Chinney Alliance Engineering Limited)	Project Director	Dennis Yam	9551 9920
	Environmental Officer	Richard Liu	9216 8990
Contract 3307 Fire Training Facility (Paul Y. Construction Company Limited)	Project Manager	Ken Tang	9640 5397
	Environmental Officer	Ferddy Leung	5585 6746
Contract 3308 Foreign Object Debris Detection System (DAS Aviation Services Group)	Project Manager	Jeffrey Yau	9873 7422
Contract 3310 North Runway Modification Works (China State Construction Engineering (Hong Kong) Ltd.)	Project Manager	Kingsley Chiang	9424 8437
	Environmental Officer	Federick Wong	9842 2703

Terminal 2 Concourse and Apron Works:

Party	Position	Name	Telephone
Contract 3402 New Integrated Airport Centres Enabling Works (Wing Hing Construction Co., Ltd.)	Project Manager	Wyman Lau	6112 9753
	Health Safety Environmental Manager	Mike Leung	6625 2550
Contract 3403 New Integrated Airport Centres Building and Civil Works (Sun Fook Kong Construction Limited)	Project Manager	Alice Leung	9220 3162
	Environmental Officer	Ray Cheung	9785 1566
Contract 3404 Integrated Airport Control System (Shun Hing Systems Integration Co., Ltd.)	Project Manager	Andy Ng	9102 2739
	Environmental Officer	Michael Lo	6228 3926
Contract 3405 Third Runway Concourse Foundation and Substructure Works (China Road and Bridge Corporation – Bachy Soletanche Group Limited – LT Sambo Co., Ltd. Joint Venture)	Project Manager	Francis Choi	9423 3469
	Environmental Officer	Jacky Lai	9028 8975
Contract 3408 Third Runway Concourse and Apron Works (Beijing Urban Construction Group Company Limited and Chevalier (Construction) Company Limited Joint Venture)	Assistant Project Manager	Qian Zhang	5377 7976
	Environmental Officer	Malcolm Leung	7073 7559

Terminal 2 Expansion:

Party	Position	Name	Telephone
Contract 3508 Terminal 2 Expansion Works (Gammon Engineering & Construction Company Limited)	Project Manager	Richard Ellis	6201 5637
Environmental Officer	Endy Tse	6228 7768

Party

Position

Name

Telephone

Contract 3508 Terminal 2

Expansion Works

(Gammon Engineering &

Construction Company

Limited)

Project Manager

Richard Ellis

6201 5637

Environmental Officer

Endy Tse

6228 7768

Automated People Mover and Baggage Handling System:

Party	Position	Name	Telephone
Contract 3601 New Automated People Mover System (TRC Line) (CRRC Puzhen Bombardier Transportation Systems Limited and CRRC Nanjing Puzhen Co., Ltd. Joint Venture)	Project Manager	Hongdan Wei	158 6180 9450
	Environmental Officer	H Y Yue	9185 8186
Contract 3602 Existing APM System Modification Works (Niigata Transys Co., Ltd.)	Project Manager	Xia Bo	6586 4950
	Environmental Officer	Y M Tong	5316 9801
Contract 3603 3RS Baggage Handling System (VISH Consortium)	Project Manager	K C Ho	9272 9626
Contract 3603 3RS Baggage Handling System (VISH Consortium)	Environmental Officer	Richard Ng	9802 9577

Airport Support Infrastructure:

Party	Position	Name	Telephone
Contract 3801 APM and BHS Tunnels on Existing Airport Island (China State Construction Engineering (Hong Kong) Ltd.)	Project Manager	Kingsley Chiang	9424 8437
	Environmental Officer	Eunice Kwok	9243 1331
Contract 3802 APM and BHS Tunnels and Related Works (Gammon Engineering & Construction Company Limited)	Project Manager	John Adams	6111 6989
	Environmental Officer	Yan Ng	5345 8555
Contract 3804 East and Landside Fire Stations (Beijing Urban Construction Group Company Limited - Beijing Urban Construction International Company Limited - Kin Shing (Leung's) General Contractors Ltd Joint Venture)	Project Manager	Mr. Zhang Xianda	4661 6818
	Environmental Officer	Ms. Kimberly Wong	5542 1669
Contract 3805 New Airport District Police Operational Base (Chinney Construction Co., Ltd.)	Project Manager	Cheuk Wing Wai	9339 8321
	Environmental Officer	Mike Li	6306 8547

Construction Support:

Party	Position	Name	Telephone
Contract 3721 Construction Support Infrastructure Works (China State Construction Engineering (Hong Kong) Ltd.)	Site Agent	Thomas Lui	9011 5340
	Environmental Officer	John Mak	6273 8703
Contract 3722 Western Support Area – Construction Support Facilities (Tapbo Construction Company Limited and Konwo Modular House Ltd. Joint Venture.)	Deputy Project Director	Philip Kong	9337 8700
	Environmental Officer	Eddie Suen	6338 8862
Contract 3723 Eastern Support Area – Construction Support Facilities (Tapbo Construction Company Limited and Konwo Modular House Ltd. Joint Venture.)	Deputy Project Director	Philip Kong	9337 8700
	Environmental Officer	Eddie Suen	6338 8862
Contract 3728 Minor Site Works (Shun Yuen Construction Company Limited)	Contract Manager	C K Liu	9194 8739
	Environmental Officer	Dan Leung	6856 5899
Contract 3733 Emergency Repair Service (Wing Hing Construction Co., Ltd.)	Project Manager	Michael Kan	9206 0550
	Health Safety Environmental Manager	Mike Leung	6625 2550
Contract 3901A Concrete Batching Facility (K. Wah Concrete Company Limited)	Project Manager	Benedict Wong	9553 2806
	Environmental Officer	C P Fung	9874 2872
Contract 3901B Concrete Batching Facility (Gammon Construction Limited)	Project Manager	Gabriel Chan	2435 3260
	Environmental Officer	Rex Wong	2695 6319
Contract 3908 Quay Management Services (Gitanes – Crown Asia Joint Venture)	Project Manager	Mr. Ian Li	9750 6438
	Environmental Officer	Mr. Tang Kai Fun	9406 3526
Contract 3913 Asphalt Batching Plant (SPR Joint Venture)	Project Manager	Xie Yi Sheng	6580 6005
Contract 3913 Asphalt Batching Plant (SPR Joint Venture)	Environmental Officer	Kenneth Chan	9300 2182

Utilities:

Party	Position	Name	Telephone
132kV Cable (CLP Power Hong Kong Limited / Kum Shing (K.F.) Construction Company Limited)	Engineer	Ken Fung	6391 9087
	Project Engineer	Ivan Shek	9822 5836

1.4 Contact Information for the Project

The contact information for the Project is provided in Table 1.2. The public can contact us through the following channels if they have any queries and comments on the environmental monitoring data and project related information.

Table 1.2: Contact Information of the Project

Channels	Contact Information
Hotline	3908 0354
Email	env@3rsproject.com
Fax	3747 6050
Postal Address	Airport Authority Hong Kong HKIA Tower 1 Sky Plaza Road Hong Kong International Airport Lantau Hong Kong Attn: Environmental Team Leader Mr Terence Kong c/o Mr Lawrence Tsui (TRD)

1.5 Summary of Construction Works

During the reporting period, the project is in the Interim Two Runway System (I-2RS) stage, in which the new North Runway and the associated taxiway and facilities were operated together with the South Runway and existing airport facilities, with the Centre Runway closed down for modification works.

The key activities of the Project carried out in the reporting period are located in reclamation areas and existing airport island respectively. Works in the reclamation areas included seawall construction, rock armour laying works, filling and land-based ground improvement works, pavement works, Terminal 2 concourse foundation and superstructure works, tunnel works for Automated People Mover (APM) and Baggage Handling System (BHS) and associated works. Land-based works on existing airport island involved mainly centre runway modification works, Terminal 2 expansion works, modification and tunnel works for APM and BHS systems, and preparation works for utilities, with activities including road and drainage works, cable ducting, demolition, piling, pile cap and excavation works and 132kV cable laying.

The locations of the works areas are presented in Figure 1.1.

1.6 Summary of EM&A Programme Requirements

The status for all environmental aspects is presented in Table 1.3.

Table 1.3: Summary of Status for All Environmental Aspects under the Manual

Parameters	EM&A Requirements	Status
Air Quality
Baseline Monitoring	At least 14 consecutive days before commencement of construction work	The baseline air quality monitoring results were reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4.
Impact Monitoring	At least 3 times every 6 days	On-going
Noise
Baseline Monitoring	Daily for a period of at least two weeks prior to the commencement of construction works	The baseline noise monitoring results were reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4.
Impact Monitoring	Weekly	On-going
Water Quality
General Baseline Water Quality Monitoring for reclamation, water jetting and field joint works	Three days per week, at mid-flood and mid-ebb tides, for at least four weeks prior to the commencement of marine works.	The baseline water quality monitoring results were reported in Baseline Water Quality Monitoring Report and submitted to EPD under EP Condition 3.4.
General Impact Water Quality Monitoring for reclamation, water jetting and field joint works	Three days per week, at mid-flood and mid-ebb tides.	General impact water quality monitoring for water jetting works was completed on 23 May 2017. The general impact water quality monitoring was terminated after 31 October 2023.
Initial Intensive Deep Cement Mixing (DCM) Water Quality Monitoring	At least four weeks	The Initial Intensive DCM Monitoring Report was submitted and approved by EPD in accordance with the Detailed Plan on DCM.
Regular DCM Water Quality Monitoring	Three times per week until completion of DCM works.	Due to the completion of all marine-based DCM works within April 2022, regular DCM monitoring was ceased at all monitoring stations starting from 28 April 2022.
Post-construction Phase Water Quality Monitoring	Three days per week, at mid-flood and mid-ebb tides for four weeks	The four-week post-construction phase water quality monitoring exercise was commenced on 14 November 2023 and completed on 9 December 2023.
Sewerage and Sewage Treatment
Methodology for carrying out annual sewage flow monitoring for concerned gravity sewer	Methodology to be prepared and submitted to EPD at least one year before commencement of the operation of 3RS	The proposed methodology of the annual sewage flow monitoring was approved by EPD. The annual flow monitoring was started from June 2021 and completed in December 2022.
Details of the routine H₂S monitoring system for the sewerage system of 3RS	Details to be prepared and submitted to EPD at least one year before commencement of the operation of 3RS	The H₂S monitoring proposal was accepted by EPD in June 2023.
Waste Management
Waste Monitoring	At least weekly	On-going
Land Contamination
Supplementary Contamination Assessment Plan (CAP)	At least 3 months before commencement of any soil remediation works.	The Supplementary CAP was submitted and approved by EPD pursuant to EP condition 2.20.
Site Re-appraisal Summary Report for Fire Training Facility	Site Re-appraisal Summary Report for Fire Training Facility	Site Re-appraisal Summary Report for Fire Training Facility was submitted and accepted by EPD.
Contamination Assessment Report (CAR)	CAR to be submitted for golf course	The CAR for Golf Course was submitted and accepted by EPD.
Contamination Assessment Report (CAR)	CAR to be submitted for Terminal 2 Emergency Power Supply Systems	The CARs for Terminal 2 Emergency Power Supply Systems were submitted and accepted by EPD.
Terrestrial Ecology
Pre-construction Egretry Survey Plan	Once per month in the breeding season between April and July, prior to the commencement of HDD drilling works.	The revised Egretry Survey Plan was submitted and approved by EPD under EP Condition 2.14.
Ecological Monitoring	Monthly monitoring during the HDD construction works period from August to March.	The terrestrial ecological monitoring at Sheung Sha Chau was completed in January 2019.
Marine Ecology
Pre-Construction Phase Coral Dive Survey	Prior to marine construction works	The Coral Translocation Plan was submitted and approved by EPD under EP Condition 2.12.
Coral Translocation	-	The coral translocation was completed on 5 January 2017.
Coral Post-translocation Monitoring	As per an enhanced monitoring programme based on the Coral Translocation Plan	The post-translocation monitoring programme according to the Coral Translocation Plan was completed in April 2018.
Chinese White Dolphins (CWD)
Baseline Monitoring	6 months of baseline surveys before the commencement of land formation related construction works. Vessel line transect surveys: Two full surveys per month; Land-based theodolite tracking surveys: Two days per month at the Sha Chau station and two days per month at the Lung Kwu Chau station; and Passive Acoustic Monitoring (PAM): For the whole duration of baseline period.	Baseline CWD results were reported in the CWD Baseline Monitoring Report and submitted to EPD in accordance with EP Condition 3.4.
Impact Monitoring	Vessel line transect surveys: Two full surveys per month; Land-based theodolite tracking surveys: One day per month at the Sha Chau station and one day per month at the Lung Kwu Chau station; and PAM: For the whole duration for land formation related construction works.	The construction phase CWD monitoring was completed in December 2023.
Post-construction Phase Monitoring	12 months of post monitoring upon the completion of marine construction works; and Vessel line transect survey: Two full surveys per month.	Post-construction phase monitoring would be commenced from January 2024.
Landscape and Visual
Landscape and Visual Plan	At least 3 months before the commencement of construction works on the formed land of the Project.	The Landscape & Visual Plan was submitted to EPD under EP Condition 2.18.
Baseline Monitoring	One-off survey within the Project site boundary prior to commencement of any construction works	The baseline landscape & visual monitoring result has been reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4.
Impact Monitoring	Weekly	On-going
Establishment Works Monitoring	Bi-monthly	On-going
Long Term Management (10 years) monitoring	Annually	On-going
Environmental Auditing
Regular site inspection	Weekly	On-going
Marine Mammal Watching Plan (MMWP) implementation measures	Monitor and check	On-going
Dolphin Exclusion Zone (DEZ) Plan implementation measures	Monitor and check	On-going
SkyPier High Speed Ferries (HSF) implementation measures	Monitor and check	On-going
Construction and Associated Vessels implementation measures	Monitor and check	On-going
Complaint Hotline and Email channel	Construction phase	On-going
Environmental Log-book	Construction phase	On-going
Silt Curtain Deployment Plan implementation measures	Monitor and check	Silt Curtain Deployment Plan was implemented at C7a during this reporting period.
Spill Response Plan implementation measures	Monitor and check	On-going

Taking into account the construction works in the reporting period, impact monitoring of air quality, noise, water quality, waste management, landscape and visual, CWD and post-construction phase water quality monitoring were carried out in the reporting period.

The EM&A programme also involved weekly site inspections and related auditing conducted by the ET for checking the implementation of the required environmental mitigation measures as recommended in the approved EIA Report. To promote the environmental awareness and enhance the environmental performance of the contractors, environmental briefings, environmental trainings, and regular environmental management meetings were conducted during the reporting period which are summarized as below:

● 2 skipper trainings provided by ET;

● 2 environmental briefings on EP and EM&A requirements of the 3RS provided by ET; and

● 202 environmental management meetings for EM&A review with works contracts.

The EM&A programme has been undertaken in accordance with the recommendations presented in the approved EIA Report and the Manual. A summary of implementation status of the environmental mitigation measures for the construction phase of the Project during the reporting period is provided in Appendix C.

2 Environmental Monitoring and Auditing

2.1 Air Quality Monitoring

Impact 1-hour Total Suspended Particulates (TSP) monitoring was conducted three times every six days at two representative monitoring stations during the reporting period. The locations of monitoring stations are described in Table 2.1 and presented in Figure 2.1.

2.1.1 Action and Limit Levels

The Action and Limit Levels of the air quality monitoring stipulated in the EM&A programme for triggering the relevant investigation and follow-up procedures under the programme are provided in Table 2.1.

Table 2.1: Impact Air Quality Monitoring Stations

Monitoring Station	Location	Action Level (mg/m³)	Limit Level (mg/m³)
AR1A	Man Tung Road Park	306	500
AR2	Village House at Tin Sum	298	500

2.1.2 Monitoring Results

The graphical plots of impact air quality monitoring results during the reporting period are presented in Appendix D. Percentage of monitoring results within their corresponding Action and Limit Levels in the reporting period are presented in Table 2.2.

Table 2.2: Percentage of Air Quality Monitoring Results within Action and Limit Levels

	AR1A	AR2
Jan 2023	100%	100%
Feb 2023	100%	100%
Mar 2023	100%	100%
Apr 2023	100%	100%
May 2023	100%	100%
Jun 2023	100%	100%
Jul 2023	100%	100%
Aug 2023	100%	100%
Sep 2023	100%	100%
Oct 2023	100%	100%
Nov 2023	100%	100%
Dec 2023	100%	100%
Overall	100%	100%
Note: The percentages are calculated by dividing the number of monitoring results within their corresponding Action and Limit Level by the total number of monitoring results.

All monitoring results at AR1A and AR2 were within their corresponding Action and Limit Levels.

General meteorological conditions throughout the impact monitoring period were recorded and summarized in Table 2.3.

Table 2.3: General Meteorological Condition during Impact Air Quality Monitoring

	Weather	Wind Direction
Jan – Mar 2023	Sunny to Cloudy	Northwest or Northeast
Apr – Jun 2023	Sunny to Drizzle	Northwest or Southeast
Jul – Sep 2023	Sunny to Drizzle	Northwest or East
Oct – Dec 2023	Sunny to Cloudy	Northwest or East

2.1.3 Conclusion

No dust emission source was observed at the monitoring stations during the monitoring sessions. As the sensitive receivers were far away from the construction activities, with the implementation of dust control measures, there was no adverse impact at the sensitive receivers attributable to the works of the Project.

2.2 Noise Monitoring

Impact noise monitoring was conducted at four representative monitoring stations once per week during 0700 and 1900 in the reporting period. The locations of monitoring stations are described in Table 2.4 and presented in Figure 2.1.

2.2.1 Action and Limit Levels

The Action and Limit levels of the noise monitoring stipulated in the EM&A programme for triggering the relevant investigation and follow-up procedures under the programme are provided in Table 2.4.

Table 2.4: Impact Noise Monitoring Stations

Monitoring Station	Location	Action Level	Limit Level
NM1A	Man Tung Road Park	When one documented complaint is received from any one of the sensitive receivers	75 dB(A)
NM4	Ching Chung Hau Po Woon Primary School		65dB(A) / 70 dB(A) ⁽ⁱ⁾
NM5	Village House in Tin Sum		75 dB(A)
NM6	House No. 1, Sha Lo Wan		75 dB(A)
Note: ⁽ⁱ⁾ The Limit Level for NM4 is reduced to 70dB(A) for being an educational institution. During school examination period, the Limit Level is further reduced to 65dB(A).

2.2.2 Monitoring Results

The graphical plots of impact noise quality monitoring results during the reporting period are presented in Appendix D. Percentage of monitoring results within their corresponding Action and Limit Levels in the reporting period are presented in Table 2.5.

Table 2.5: Percentage of Noise Monitoring Results within Action and Limit Levels

	NM1A	NM4	NM5	NM6
Jan 2023	100%	100%	100%	100%
Feb 2023	100%	100%	100%	100%
Mar 2023	100%	100%	100%	100%
Apr 2023	100%	100%	100%	100%
May 2023	100%	100%	100%	100%
Jun 2023	100%	100%	100%	100%
Jul 2023	100%	100%	100%	100%
Aug 2023	100%	100%	100%	100%
Sep 2023	100%	100%	100%	100%
Oct 2023	100%	100%	100%	100%
Nov 2023	100%	100%	100%	100%
Dec 2023	100%	100%	100%	100%
Overall	100%	100%	100%	100%
Note: The percentages are calculated by dividing the number of monitoring results within their corresponding Action and Limit Level by the total number of monitoring results.

No complaints were received from any sensitive receiver that triggered the Action Level.

General weather conditions throughout the impact monitoring period were recorded and summarized in Table 2.6.

Table 2.6: General Weather Condition during Impact Noise Monitoring

	Weather
Jan – Mar 2023	Sunny to Cloudy
Apr – Jun 2023	Sunny to Drizzle
Jul – Sep 2023	Sunny to Drizzle
Oct – Dec 2023	Sunny to Cloudy

2.2.3 Conclusion

Major sources of noise dominating the monitoring stations observed during the construction noise impact monitoring were road traffic noise near NM1A, school activities at NM4, and aircraft noise near NM6. As the sensitive receivers were far away from the construction activities, with the implementation of noise control measures, there was no adverse impact at the sensitive receivers attributable to the works of the Project.

2.3 Water Quality Monitoring

Impact water quality monitoring of the Project had commenced since 4 August 2016. The monitoring was first conducted three days per week, at mid-ebb and mid-flood tides, at 23 water quality monitoring stations, comprising 12 impact (IM) stations, 8 sensitive receiver (SR) stations, and 3 control (C) stations in the vicinity of the water quality sensitive receivers around the existing airport island in accordance with the Updated EM&A Manual. The purpose of water quality monitoring at the IM stations is to promptly capture any potential water quality impacts from the Project before the impacts could become apparent at sensitive receivers (represented by the SR stations). In view of the progress of 3RS land formation with majority of seawall completion, reduction of IM and SR stations for impact water quality monitoring was proposed to EPD with approval granted on 22 December 2021. The reduction of IM and SR stations was effective from 25 January 2022, in which the remaining IM stations were relocated back to their original locations according to coordinates provided in Table 5.2 of the Updated EM&A Manual, with slight modifications to the location of IM2. After the reduction of monitoring stations, there was a total of 14 water quality monitoring stations, comprising 6 impact (IM) stations, 5 sensitive receiver (SR) stations and 3 control (C) stations. The land formation works including seawall construction and all marine filling works was completed in the first quarter of 2023. However, as a precautionary measure, water quality impact monitoring continued until the end of the rainy season. Subsequently, a proposal for terminating the general impact water quality monitoring during the construction phase was submitted to the EPD and received approval on 30 October 2023. The general water quality impact monitoring was terminated after 31 October 2023 and the post-construction phase water quality monitoring exercise was then carried out for four weeks afterwards. Table 2.7 describes the details of the monitoring stations during the reporting period and their locations are shown in Figure 2.2a.

Table 2.7: Monitoring Locations and Parameters for General Impact Water Quality Monitoring

Monitoring Stations	Description	Coordinates		Parameters
		Easting	Northing
C1	Control Station	804247	815620	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS
C2	Control Station	806945	825682
C3⁽²⁾	Control Station	817803	822109
IM1⁽³⁾	Impact Station	806458	818351
IM2⁽³⁾⁽⁴⁾	Impact Station	806236	819183
IM7⁽³⁾	Impact Station	806835	821349
IM10⁽³⁾	Impact Station	809838	822240
IM11⁽³⁾	Impact Station	810545	821501
IM12⁽³⁾	Impact Station	811519	821162
SR1A⁽¹⁾	Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities (HKBCF) Seawater Intake for cooling	812660	819977	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS
SR2	Planned marine park / hard corals at The Brothers / Tai Mo To	814166	821463	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS
SR3	Sha Chau and Lung Kwu Chau Marine Park / fishing and spawning grounds in North Lantau	807571	822147	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS
SR4A	Sha Lo Wan	807810	817189
SR8	Seawater Intake for cooling at Hong Kong International Airport (East)	811623	820390

Notes:

(1) With the operation of HKBCF, water quality monitoring at SR1A station was commenced on 25 October 2018. To better reflect the water quality in the immediate vicinity of the intake, the monitoring location of SR1A was shifted closer to the intake starting from 5 January 2019.

(2) According to the Baseline Water Quality Monitoring Report, C3 station is not adequately representative as a control station of impact/ SR stations during the flood tide. The control reference was changed from C3 to SR2 from 1 September 2016 onwards.

(3) With the seawall completion and removal of enhanced open sea silt curtains, these monitoring stations were relocated back to their original locations.

(4) The reduction of IM and SR stations was effective from 25 January 2022, in which the remaining IM stations were relocated back to their original locations according to coordinates provided in Table 5.2 of the Updated EM&A Manual, with slight modifications to the location of IM2. For IM2, there was minor adjustment which was shifted 334m northwards from original location to improve coverage of the remaining marine works after 25 January 2022 to promptly capture any potential water quality impacts from the Project before the impacts could become apparent during the reporting period.

2.3.1 Action and Limit Levels

The Action and Limit Levels for general impact water quality monitoring stipulated in the EM&A programme for triggering the relevant investigation and follow-up procedures under the programme are presented in Table 2.8. The control and impact stations during flood tide and ebb tide for general impact water quality monitoring are presented in Table 2.9. The weather and sea conditions during the reporting period were recorded and are summarized in Table 2.10.

Table 2.8: Action and Limit Levels for General Impact Water Quality Monitoring

Parameters		Action Level (AL)		Limit Level (LL)
Action and Limit Levels for general impact water quality monitoring (excluding SR1A & SR8)
General Water Quality Monitoring	DO in mg/l (Surface, Middle & Bottom)	Surface and Middle 4.5mg/l		Surface and Middle 4.1mg/l
	DO in mg/l (Surface, Middle & Bottom)	Bottom 3.4mg/l		Bottom 2.7mg/l
	Suspended Solids (SS) in mg/l	23	or 120% of upstream control station at the same tide of the same day, whichever is higher	37	or 130% of upstream control station at the same tide of the same day, whichever is higher
	Turbidity in NTU	22.6		36.1
Action and Limit Levels SR1A
SS (mg/l))		33		42
Action and Limit Levels SR8
SS (mg/l)		52		60

Notes:

⁽¹⁾For DO measurement, Action or Limit Level is triggered when the monitoring result is lower than the limits.

⁽²⁾For parameters other than DO, Action or Limit Level of water quality results is triggered when monitoring results is higher than the limits.

⁽³⁾Depth-averaged results are used unless specified otherwise.

Table 2.9: The Control and Impact Stations during Flood Tide and Ebb Tide for General Impact Water Quality Monitoring

Control Stations	Impact Stations
Flood Tide
C1	IM1, IM2, IM7, SR3
SR2⁽¹⁾	IM7, IM10, IM11, IM12, SR1A, SR3, SR4A, SR8
Ebb Tide
C1	SR4A
C2	IM1, IM2, IM7, IM10, IM11, IM12, SR1A, SR2, SR3, SR8

Notes:

⁽¹⁾As per findings of Baseline Water Quality Report, the control reference was changed from C3 to SR2 from 1 September 2016 onwards.

Table 2.10: General Weather Condition and Sea Condition during General Impact Water Quality Monitoring

	Weather	Sea Condition
Jan – Mar 2023	Sunny to Rainy	Calm to Rough
Apr – Jun 2023	Sunny to Rainy	Calm to Rough
Jul – Sep 2023	Sunny to Rainy	Calm to Rough
Oct 2023	Sunny to Rainy	Calm to Rough

2.3.2 Monitoring Results

Percentage of monitoring results within their corresponding Action and Limit Levels in the reporting period are presented in Table 2.11. It should be noted that Hong Kong was under the effect of tropical cyclones from 15 to 18, 26 to 28 July, 30 to 31 August, 1 to 2, 4 to 5 September, 4 to 9 October 2023 respectively, and the water quality monitoring results during the said periods might be affected by the inclement weather.

Table 2.11: Percentage of General Impact Water Quality Monitoring Results within Action and Limit Levels

		General Impact Water Quality Monitoring
	DO (Surface and Middle)		DO (Bottom)	SS	Turbidity
Jan 2023	100.0%		100.0%	100.0%	100%
Feb 2023	100.0%		100.0%	99.6%	100%
Mar 2023	100.0%		100.0%	99.6%	100%
Apr 2023	100.0%		100.0%	100.0%	100%
May 2023	100.0%		100.0%	100.0%	100%
Jun 2023	100.0%		96.8%	100.0%	100%
Jul 2023	99.5%		97.7%	100.0%	100%
Aug 2023	94.5%		97.5%	100.0%	100%
Sep 2023	100.0%		100.0%	100.0%	100%
Oct 2023	100.0%		100.0%	99.6%	100%
Overall	99.4%		99.2%	99.9%	100%

The monitoring results for turbidity obtained in the reporting period were within their corresponding Action and Limit Levels.

For DO and SS, some of the testing results triggered the corresponding Action or Limit Levels in the reporting period. Investigations were conducted accordingly and the details were presented in the corresponding Construction Phase Monthly EM&A Reports. The status of each water quality parameter collected in the reporting period are presented graphically in Appendix D. Some of these cases were recorded at monitoring stations located upstream of the Project based on dominant tidal flow and were considered not affected by the Project. Investigations focusing on the cases which occurred at monitoring stations located downstream of the Project were carried out and the details were presented in the corresponding Construction Phase Monthly EM&A Reports. Investigations confirmed that construction works were conducted with proper implementation of mitigation measures during concerned monitoring days. Based on respective investigation findings, cases triggering Action or Limit Level located upstream and downstream were found not related to the Project.

2.3.3 Conclusion

During the reporting period, it was noted that the vast majority of monitoring results (from 99.2% for DO (Bottom), 99.4% for DO (Surface and Middle) and 99.9 % for SS, to 100% for turbidity as presented in Table 2.11) were within their corresponding Action and Limit Levels, while only a minor number of results triggered their corresponding Action or Limit Level, and investigations were conducted. Based on the findings of the investigations presented in the Construction Phase Monthly EM&A Reports for 2023, all results that triggered the corresponding Action or Limit Level were not related to the Project. Therefore, the Project did not cause adverse impact at the water quality sensitive receivers. All required actions under the Event and Action Plan were followed. These cases were considered due to natural fluctuation or other sources not related to the Project.

2.4 Post-construction Phase Water Quality Monitoring

A post-construction phase water quality monitoring exercise was carried out for four weeks according to Section 5.1.10.1 of the Updated EM&A Manual, in the same manner as the impact monitoring at all monitoring stations during construction phase, from 14 November 2023 to 9 December 2023.

Post-construction phase water quality monitoring of DO, pH, temperature, salinity, turbidity, suspended solids (SS), total alkalinity, Chromium, and Nickel has been conducted three days per week, at mid-ebb and mid-flood tides, at a total of 23 water quality monitoring stations, comprising 12 impact (IM) stations, 8 sensitive receiver (SR) stations and 3 control (C) stations in the vicinity of water quality sensitive receivers around the airport island in accordance with the Updated EM&A Manual. The details of the monitoring stations are shown in Table 2.12 and the control and impact stations during ebb tide and flood tide for post-construction phase water quality monitoring are presented in Table 2.13. Figure 2.2b shows the locations of the monitoring stations for post-construction phase water quality monitoring.

Table 2.12: Monitoring Locations for Post-construction Phase Water Quality Monitoring

Monitoring Stations	Description	Coordinates		Parameters
		Easting	Northing
C1	Control Station	804247	815620	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS DCM Parameters Total Alkalinity, Heavy Metals
C2	Control Station	806945	825682
C3⁽²⁾	Control Station	817803	822109
IM1	Impact Station	806458	818351
IM2	Impact Station	806193	818852
IM3	Impact Station	806019	819411
IM4	Impact Station	805039	819570
IM5	Impact Station	804924	820564
IM6	Impact Station	805828	821060
IM7	Impact Station	806835	821349
IM8	Impact Station	807838	821695
IM9	Impact Station	808811	822094
IM10	Impact Station	809838	822240
IM11	Impact Station	810545	821501
IM12	Impact Station	811519	821162
SR1A⁽¹⁾	Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities (HKBCF) Seawater Intake for cooling	812660	819977	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS
SR2	Planned marine park / hard corals at The Brothers / Tai Mo To	814166	821463	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS DCM Parameters Total Alkalinity, Heavy Metals
SR3	Sha Chau and Lung Kwu Chau Marine Park / fishing and spawning grounds in North Lantau	807571	822147	General Parameters DO, pH, Temperature, Salinity, Turbidity, SS
SR4A	Sha Lo Wan	807810	817189
SR5A	San Tau Beach SSSI	810696	816593
SR6 ⁽³⁾	Tai Ho Bay, Near Tai Ho Stream SSSI	814663	817899
SR7	Ma Wan Fish Culture Zone (FCZ)	823742	823636
SR8	Seawater Intake for cooling at Hong Kong International Airport (East)	811623	820390

Notes:

(3) As the access to SR6 was obstructed by the construction activities and temporary structures for Tung Chung New Town Extension, the monitoring location was relocated to SR6A starting from 8 August 2019. Since construction activities and temporary structures for Tung Chung New Town Extension no longer exist, monitoring location of SR6 was adopted according to the Baseline Water Quality Monitoring Report.

Table 2.13: The Control and Impact Stations during Flood Tide and Ebb Tide for Post-construction Phase Water Quality Monitoring

Control Stations	Impact Stations
Flood Tide
C1	IM1, IM2, IM3, IM4, IM5, IM6, IM7, IM8, SR3
SR2⁽¹⁾	IM7, IM8, IM9, IM10, IM11, IM12, SR1A, SR3, SR4A, SR5A, SR6, SR8
Ebb Tide
C1	SR4A, SR5A, SR6
C2	IM1, IM2, IM3, IM4, IM5, IM6, IM7, IM8, IM9, IM10, IM11, IM12, SR1A, SR2, SR3, SR7, SR8

Note:

(1) As per findings of Baseline Water Quality Monitoring Report, the control reference has been changed from C3 to SR2 from 1 September 2016 onwards.

2.4.1 Summary of Monitoring Results

Summary of the post-construction phase water quality monitoring results is presented in Part II of Appendix D. The water quality monitoring results for the entire monitoring period, i.e., baseline monitoring (from 3 to 14 May, from 19 to 30 July, from 4 to 30 August and from 1 to 29 September 2016); general impact water quality monitoring (from 1 October 2016 to 31 October 2023) and post-construction monitoring (from 14 November to 9 December 2023), are also graphically presented in Part III of Appendix D.

The distributions of all monitoring results over the entire water quality monitoring period are illustrated in Graphs D.1 to D.14 in Part IV of Appendix D. These graphs are presented in Box-and-Whisker diagrams which show the distribution of monitoring results in terms of their mean, median (Q2), interquartile range (IQR), quartile 1 (Q1), quartile 3 (Q3), minimum (lower bound), maximum (upper bound) and outlier values. The definitions of these descriptors are presented below:

· Mean: Arithmetic average of the data

· Median (Q2): 50^th-percentile of the data

· Quartile 1(Q1): 25^th-percentile of the data

· Quartile 3 (Q3): 75^th-percentile of the data

· Interquartile Range (IQR): Q3 – Q1

· Minimum (Lower bound): Q1 – 1.5 x IQR

· Maximum (Upper bound): Q3 + 1.5 x IQR

· Outliers: Data beyond the upper bound or below the lower bound.

Analysis of each water quality monitoring parameter is provided in subsequent paragraphs.

Dissolved Oxygen:

According to Graphs D.1 to D.4, the following observations were made for the distribution of DO monitoring results during the entire monitoring period:

· The mean and median values of DO during post-construction phase monitoring are higher than the corresponding values during baseline water quality monitoring.

· The interquartile ranges of DO during post-construction phase were found to be generally higher than the corresponding ranges during baseline water quality monitoring.

· During general impact water quality monitoring, while outliers of low DO values were observed, investigations had been carried out according to the relevant requirements of the Updated EM&A Manual whenever such outliners triggered the Action or Limit Levels, and the investigation findings concluded that such low DO levels were not due to the Project but could be attributed to natural fluctuation/ seasonal variations/ external factors in the vicinity. Details of the investigation findings have been documented in the relevant Construction Phase Monthly EM&A Reports.

Based on the above analysis, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in the DO levels of the marine water surrounding the Project site.

Turbidity:

According to Graphs D.5 and D.6, for following observations were made for the distribution of turbidity monitoring results during the entire monitoring period:

· The mean and median values of turbidity during post-construction phase monitoring are lower than the corresponding values during baseline water quality monitoring.

· The interquartile ranges of turbidity during post-construction phase were found to be generally lower than the corresponding ranges during baseline water quality monitoring.

· During general impact water quality monitoring, while outliers of high turbidity were observed, investigations had been carried out according to the relevant requirements of the Updated EM&A Manual whenever such outliners triggered the Action or Limit Levels, and the investigation findings concluded that such high turbidity levels were not due to the Project but could be attributed to natural fluctuation/ seasonal variations/ external factors in the vicinity. Details of the investigation findings have been documented in the relevant Construction Phase Monthly EM&A Reports.

Based on the above analysis, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in the turbidity levels of the marine water surrounding the Project site.

Suspended Solid (SS):

According to Graphs D.7 and D.8, the following observations were made for the distribution of SS monitoring results during the entire monitoring period:

· The mean and median values of SS during post-construction phase monitoring are lower than the corresponding values during baseline water quality monitoring.

· The interquartile ranges of SS during post-construction phase were found to be generally lower than the corresponding ranges during baseline water quality monitoring.

· During general impact water quality monitoring, while outliers of high SS values were observed, investigations had been carried out according to the relevant requirements of the Updated EM&A Manual whenever such outliners triggered the Action or Limit Levels, and the investigation findings concluded that such high SS levels were not due to the Project but could be attributed to natural fluctuation/ seasonal variations/ external factors in the vicinity. Details of the investigation findings have been documented in the relevant Construction Phase Monthly EM&A Reports.

Based on the above analysis, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in the SS levels of the marine water surrounding the Project site.

Alkalinity:

According to Graphs D.9 and D.10, the following observations were made for the distribution of alkalinity monitoring results during the entire monitoring period:

· The mean and median values of alkalinity during post-construction phase monitoring are lower than the corresponding values during baseline water quality monitoring.

· The interquartile ranges of alkalinity during post-construction phase were found to be generally lower than the corresponding ranges during baseline water quality monitoring.

· During general impact water quality monitoring, while outliers of high alkalinity values were observed, no exceedances of the relevant Action or Limit Levels were recorded as documented in all the previous Construction Phase Monthly EM&A Reports.

Based on the above analysis, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in the alkalinity levels of the marine water surrounding the Project site.

Chromium:

According to Graphs D.11 and D.12, the following observations were made for the distribution of chromium monitoring results during the entire monitoring period:

· The mean and median values of chromium during post-construction phase monitoring are close to the corresponding value during baseline water quality monitoring.

· The interquartile ranges of chromium during post-construction phase were found to be close to the corresponding ranges during baseline water quality monitoring.

· During general impact water quality monitoring, while outliers of high chromium values were observed, investigations had been carried out according to the relevant requirements of the Updated EM&A Manual whenever such outliners triggered the Action or Limit Levels, and the investigation findings concluded that such high chromium levels were not due to the Project but could be attributed to natural fluctuation/ seasonal variations/ external factors in the vicinity. Details of the investigation findings have been documented in the relevant Construction Phase Monthly EM&A Reports.

Based on the above analysis, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in the chromium levels of the marine water surrounding the Project site.

Nickel:

According to Graphs D.13 and D.14, the following observations were made for the distribution of nickel monitoring results during the entire monitoring period:

· The mean and median values of nickel during post-construction phase monitoring are lower than the corresponding values during baseline water quality monitoring.

· The interquartile ranges of nickel during post-construction phase were found to be lower than the corresponding ranges during baseline water quality monitoring.

· During general impact water quality monitoring, while outliers of high nickel were observed, investigations had been carried out according to the relevant requirements of the Updated EM&A Manual whenever such outliners triggered the Action or Limit Levels, and the investigation findings concluded that such high nickel levels were not due to the Project but could be attributed to natural fluctuation/ seasonal variations/ external factors in the vicinity. Details of the investigation findings have been documented in the relevant Construction Phase Monthly EM&A Reports.

Based on the above analysis, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in the nickel levels of the marine water surrounding the Project site.

2.4.2 Conclusion

Based on the above analysis, the post-construction phase water quality monitoring did not reveal significant changes of the water quality when comparing with baseline water quality monitoring, and it can be concluded that the marine works of the Project during construction phase did not cause deterioration in or adverse impacts on the marine water quality surrounding the Project site.

2.5 Waste Monitoring

In accordance with the Manual, the waste generated from construction activities was audited once per week to determine if waste was being managed in accordance with the Waste Management Plan (WMP) prepared for the Project, contract specific WMP, and any statutory and contractual requirements. All aspects of waste management including waste generation, storage, transportation, and disposal were reviewed during the audits.

2.5.1 Action and Limit Levels

The Action and Limit Levels of the construction waste are provided in Table 2.14.

Table 2.14: Action and Limit Levels for Construction Waste

Monitoring Stations	Action Level	Limit Level
Construction Area	When one valid documented complaint is received	Non-compliance of the WMP, contract-specific WMPs, any statutory and contractual requirements

2.5.2 Summary of Monitoring Results

Weekly monitoring on all works contracts were carried out by the ET in the reporting period to check and monitor the implementation of proper waste management practices.

Recommendations made included provision and maintenance of proper chemical waste storage area, as well as proper handling, segregation, and regular disposal of general refuse. Paper, plastics, and metals were recycled in the reporting period. The contractors implemented the recommended measures to improve waste management issues. Waste management audits were carried out by ET according to the requirement of the WMP, the Manual, and the implementation schedule of the waste management mitigation measures in Appendix C.

The construction waste generated in the reporting period is summarized in Table 2.15.

Table 2.15: Statistics of Construction Waste Generated in the Reporting Period

	Construction and Demolition Material Stockpiled for Reuse or Recycle⁽¹⁾ (m³)	Construction and Demolition Material Reused in the Project⁽²⁾ (m³)	Construction and Demolition Material Reused in other Projects⁽²⁾ (m³)	Construction and Demolition Material Transferred to Public Fill (m³)	Chemical Waste (kg)	Chemical Waste (L)	General Refuse (tonne)
Jan 2023	1,051	3,484	534	5,066	1,500	2,600	2187
Feb 2023	623	1,527	788	7,639	0	0	2833
Mar 2023	1,549	219	1,546	11,641	3,500	2,406	3385
Apr 2023	2,037	2,494	605	10,665	0	0	2781
May 2023	124	11,000	795	10,613	0	0	3006
Jun 2023	45	10,031	718	4,750	2,000	0	3216
Jul 2023	848	6,614	1,301	5,319	0	0	3304
Aug 2023	210	11,050	1,632	6,849	0	0	3580
Sep 2023	0	1,640	1,216	5,439	1,300	0	3143
Oct 2023	0	2,440	64	6,902	0	0	3958
Nov 2023	0	4,170	0.000	7,731	1,200	7,200	5029
Dec 2023	0	3,498	0.000	4,467	450	940	4135
Total	6,487	58,167	9,199	87,081	9,950	13,146	40557
Notes: 1. The excavated materials were temporarily stored at stockpiling area and would be reused in the Project. 2. According to latest update by Contractor, the values in Construction and Demolition Material Reused in the Projects and Construction and Demolition Material Reused in other Projects in 2023 are updated.

Starting from the year of 2018, the Project began to reuse numerous inert Construction and Demolition (C&D) materials from Government’s Public Fill Banks including Tuen Mun Area 38 and Tseung Kwan O Area 137 for land formation work. This practice is considered beneficial for maximizing the use of suitable public fill materials from Government’s Public Fill Banks for the Project. The quantity of public fill import for the year of 2023 was 2,296,962.06 tonnes. The accumulative amount of public fill import up to the year of 2023 was 24,986,761.69 tonnes.

There was no complaint, non-compliance of the WMP, contract-specific WMPs, statutory and contractual requirements that triggered Action and Limit Levels in this reporting period.

2.5.3 Marine Sediment Management

Marine sediment was managed according to the EIA Report, Updated EM&A Manual and WMP and the proposal of Further Development on Treatment Level / Details and the Reuse Mode for Marine Sediment (hereinafter referred to as “Further Development Proposal”) of the Project. Based on EIA requirements, marine sediments would be treated using cement mixing and stabilisation/solidification method. All these treated sediments would be reused on-site as backfilling materials. The sampling process, storage conditions of the excavated marine sediment, treatment process, final backfilling location as well as associated records were inspected and checked by ET and verified by IEC to ensure they were in compliance with the requirements as stipulated in the WMP and Further Development Proposal.

The treatment and backfilling works for all marine sediment excavated from the areas without ground improvement works by Deep Cement Mixing (Refer to Section 2.5.3.2) were deemed to be completed in 2022.

2.5.3.1 Reclaimed Land Area with Ground Improvement Works by Deep Cement Mixing

With reference to the Further Development Proposal approved on 17 January 2020, the marine sediment generated from the areas with ground improvement works of the 3RS Project was treated in-situ with cement by DCM, and the excavated materials would be reused on-site without disposal to sea, it was considered more appropriate to have the excavated materials tested against Risk Based Remediation Goals (RBRGs). Therefore, as an alternative to the testing arrangement presented in the 3RS EIA Report, the assessment approach provided in the EPD’s Practice Guide for Investigation and Remediation of Contaminated Land (hereafter referred to as “Practice Guide”) was adopted and the quality of excavated marine sediment was assessed against the most stringent RBRG limits (for Rural Residential Land Use) for eight heavy metals including Arsenic, Cadmium, Chromium, Lead, Mercury, Nickel, Zinc and Copper.

If the testing results were below the RBRGs limits, no further environmental treatment would be required for the marine sediment materials excavated from the sampling grid. However, geotechnical treatment might require for marine sediment to improve the quality as backfilling materials. If there was RBRGs exceedance in a particular heavy metal at a certain sampling depth, only excavated sediment material from such sampling depth of the concerned sampling grid, would undergo further cement stabilization, before testing against the Toxicity Characteristics Leaching Procedure (TCLP) limit of the concerned heavy metal (heavy metal parameter exceeded RBRGs) before reuse. For TCLP limits, please refer to Table 2.16 (Table 4.6 of the Practice Guide). The excavated sediment materials from such sampling depth with exceedance of RBRGs, would be tested against Unconfined Compressive Strength (UCS) after treatment. The UCS was defined based on respective engineering requirements. The testing frequency for TCLP was the same as that described in Section 10.5.1.14 of the approved EIA Report, i.e. one sample per 50 m³ for the first 1,000 m³ batch of excavated sediment materials. Provided that the samples meet the TCLP limit(s), the subsequent testing frequency would be reduced to be at least two samples per 10,000 m³ batch. In the event that the required level was not achieved, the concerned whole batch should be crushed and the material would be further handled and treated as necessary. The testing frequency should be revised to one sample per 50 m³ batch (with two further samples kept for contingency) and treated samples should be taken for laboratory testing. Once the concerned heavy metal complied with the particular TCLP limit, the previous sampling frequency of at least two samples per 10,000 m³batch should be resumed.

Table 2.16: Universal Treatment Standards for On-site Reuse of Sediment Treated by Cement Mixing and Stabilization

Parameters⁽¹⁾⁽²⁾	TCLP Limit (mg/L)
Arsenic	5
Cadmium	0.11
Total Chromium	0.6
Lead	0.75
Mercury	0.025
Nickel	11
Zinc	4.3

Notes:

1. Universal Treatment Standard – US 40 CFR 268.48

2. For copper, it must be reduced by at least 90% in mobility for copper through cement stabilization/solidification remedial treatment. The reduction of mobility of copper (leachable metals contaminant) should be confirmed through TCLP tests (i.e. to carry out TCLP test for the untreated sediment and for the sediment after treatment and to compare the concentrations of copper in the leachates).

A sampling grid size of 100 m x 100 m was adopted for locating sampling points for areas where marine sediment to be excavated from the newly reclaimed area. One marine sediment sample was taken if the depth of marine sediment to be excavated was less than or equalled to 3 m. If the depth of marine sediment to be excavated was less than or equalled to 6 m, a sample was taken from the depth of 0 - 3 m, and 3 - 6 m. If the marine sediment to be excavated was more than 6 m, a sample was taken from three different depths including one in the depth of 0 - 3 m, 3 - 6 m, and 6 m to the bottom of the marine sediment to be excavated. All above testing were carried out by HOKLAS laboratory, and the results were checked by ET and IEC.

The tentative location of sampling grids where marine sediment is to be excavated from the newly reclaimed area land was presented in Appendix A of the Further Development Proposal. Figure 2.3 all the sampling grids covering all the areas where marine sediment was excavated from the newly reclaimed land up to the end of the reporting period. The sampling grid for each area is denoted by specific colour, the sampling grids with light green and light red shaded represent all sampling layer(s) passed RBRGs limit(s) and sampling layer(s) with parameter(s) exceeding RBRGs limit(s), respectively. Details of sampling ID and sampling depths are also presented in each sampling grid. The number of grids for sampling for each area, the number of grids with pass and fail of the RBRGs results, the number of grids with marine sediment not encountered within the final excavation level and the number of grids to be sampled in future reporting period are all summarised in Table 2.17.

Table 2.17: Summary of Marine Sediment Testing Results for Sampling Grids within the Reclaimed Land Area with Excavation

Sampling Area	Western Vehicular Tunnel	Eastern Vehicular Tunnel	Airport North Fire Station	Terminal 2 Concourse	APM/BHS Tunnel and Ancillary Building with Piled Foundation
Grid Sampling and Testing
Total No. of Grids for Areas where Marine Sediment was Excavated (a)+(b)+(c)	15	11	1	36	34
No. of Grids with “Pass” RBRGs Results (a)	14	7	1	34	30
No. of Grids with “Fail” RBRGs Results (b)	0	0	0	2	3
No. of Grids with Marine Sediment Not Encountered within the Final Excavation Level (c)	1	4⁽¹⁾	0	0	1
Total No. of Grids for Areas where Marine Sediment is not Required for Excavation under Current Status	0	0	0	14⁽²⁾	0
Note: (1) RBRG testing was conducted for one of the sampling grids and the testing results exceeded the RBRG limits. However, the contractor re-confirmed that the marine sediment excavation will not reach the “fail” RBRG level. (2) There is no schedule that excavation will be required at the western portion of the T2C until the completion of the works. Therefore, no marine sediment sampling or excavation is required for this area under current status.

2.5.3.1.1 Western Vehicular Tunnel and Airport North Fire Station

The Western Vehicular Tunnel (WVT) and Airport North Fire Station were covered by Contracts 3303 and 3310. There were total 16 numbers of sampling grids and all the testing results passed the RBRGs limits, and the excavation of marine sediment in WVT and North Fire Station were completed.

Western Vehicular Tunnel

Construction of WVT was covered by Contracts 3303 and 3310. For Contract 3310, there was 1 sampling grid and the testing result indicated no marine sediment encounter within final excavation level. Therefore, no marine sediment was generated from Contract 3310 up to December 2023. For Contract 3303, there were 14 sampling grids and all passed the RBRGs limits. Up to this reporting period, a total of 295,283 m³treated marine sediment was backfilled and the backfilling locations are shown in Figure 2.4. Remaining excavated marine sediment was stockpiled properly at 3RS project site area and awaited for geotechnical treatment and backfilling by other contractor.

North Fire Station

Construction of North Fire Station was covered by Contract 3303, there was 1 sampling grid and the result passed the RBRGs limits. Up to this reporting period, 9,269 m³treated marine sediment was backfilled and the backfilling location is shown in Figure 2.4.

2.5.3.1.2 Eastern Vehicular Tunnel and Terminal 2 Concourse

The Eastern Vehicular Tunnel (EVT) and Terminal 2 Concourse (T2C) were covered by Contracts 3405, 3310 and 3408. Out of the total 47 numbers of sampling grids for EVT and T2C, 2 sampling grids with Arsenic exceeding RBRGs limit were recorded and reported in the previous Annual Report.

Terminal 2 Concourse

T2C was covered by Contract 3405. Out of 36 numbers of sampling grids, 2 sampling grids were recorded with Arsenic exceeding the RBRGs limit and the remaining 34 sampling grids passed all the RBRG limits. The Contractor was carrying out (1) the marine sediment excavation works; (2) geotechnical treatment for excavated marine sediment which passed RBRG limits; (3) environmental treatment and TCLP testing sampling works for excavated marine sediment which exceeded RBRG limits; and (4) treated marine sediment backfilling works during the reporting period. Up to this reporting period, all marine sediment within final excavation levels at T2C was excavated. All marine sediment that exceeded RBRGs limit was treated and backfilled. A total of 103,181 m³ treated marine sediment including marine sediment which passed and exceeded RBRGs limit was backfilled. The backfilling locations are shown in Figure 2.4. The remaining excavated marine sediment that passed RBRGs limit was stockpiled properly at 3RS project site area and awaited for geotechnical treatment before backfilling.

No marine sediment sampling or excavation works at the western portion of T2C were undertaken in the reporting period and will be subject to future development programme at this area.

Eastern Vehicular Tunnel

EVT was covered by Contracts 3310 and 3408. For Contract 3310, there was 1 sampling grid and the testing result indicated no marine sediment encounter within final excavation level. Therefore, no marine sediment was generated from Contract 3310 up to December 2023. For Contract 3408, out of 10 numbers of sampling grids, 3 sampling grids were recorded with marine sediment not encountered within the final excavation level and the remaining of 7 sampling grids passed all the RBRG limits. The Contractor was carrying out (1) marine sediment excavation works and (2) geotechnical treatment for excavated marine sediment which passed RBRGs limit during this reporting period. The excavated marine sediment was stockpiled properly at 3RS project site area and awaited for geotechnical treatment before backfilling. The treated marine sediment was stockpiled properly on site and no marine sediment backfilling works was conducted in the reporting period.

2.5.3.1.3 APM / BHS Tunnel and Ancillary Buildings with Piled Foundations

The APM / BHS Tunnel and Ancillary Buildings with Piled Foundations was covered by Contracts 3802, 3804 and 3805. Contract 3804 conducted one newly sampling grid at Grid 34 during the reporting period as shown in Figure 2.3, and the testing result passed all RBRGs limits as shown in Appendix E. Out of 34 numbers of sampling grids, three sampling grids were recorded with Arsenic exceeding the RBRGs limit, one sampling grid was recorded with marine sediment not encountered within the final excavation level and the remaining 30 sampling grids passed all the RBRGs limits.

APM / BHS Tunnel

Construction of APM/ BHS Tunnel was covered by Contract 3802. There were total 33 numbers of sampling grids and three sampling grids exceeded RBRGs limits. During the reporting period, Contractor 3802 was carrying out (1) the marine sediment excavation works; (2) geotechnical treatment for excavated marine sediment which passed RBRGs limits; and (3) backfilling works for treated marine sediment. Up to this reporting period, 1,599m³ treated marine sediment was backfilled and the backfilling locations are shown in Figure 2.4. The remaining excavated marine sediment was stockpiled properly at 3RS project site area and awaited for geotechnical treatment before backfilling. Up to December 2024, all excavated marine sediment with exceedance in RBRGs limit was treated to meet the TCLP limits and stockpiled on 3RS project site separately from the treated marine sediment that passed RBRGs limits, and awaiting for backfilling.

Ancillary Buildings with Piled Foundations

Construction of East Fire station and Landside Fire Station were covered by Contract 3804. Out of 6 numbers of sampling grids (refer to Figure 2.3, 3802-BHS/APM-Grid 6, 18, 19, 20, 21 & 3804-EFS-Grid 1), 1 sampling grid was recorded with Arsenic exceeding the RBRGs limit and the remaining five sampling grids passed all the RBRGs limits. During the reporting period, the Contractor was carrying out marine sediment excavation works for bored piling works, and all the excavated marine sediment was stockpiled properly at 3RS project site area and awaited for geotechnical treatment/ environmental treatment. Their TCLP sampling results and backfilling location would be reported in the next Annual EM&A Report.

Construction of the New Airport District Police Operational Base was covered by Contract 3805. All four numbers of sampling grids passed all the RBRGs limit. During the reporting period, the Contractor was carrying out (1) marine sediment excavation works for bored piled works; (2) geotechnical treatment for the excavated marine sediment which passed RBRGs limit; and (3) backfilling works for treated marine sediment. Up to this reporting period, 3,798m³ treated marine sediment was backfilled and backfilling location is shown in Figure 2.4. The remaining excavated and treated marine sediment was stockpiled properly at 3RS project site area and awaited for geotechnical treatment and backfilling, respectively.

2.5.3.2 Area without Ground Improvement Works by Deep Cement Mixing

For the excavated marine sediment generated from the areas without ground improvement works by DCM (i.e. construction berth at Area C5 of the reclaimed land area, existing airport island area and approach light area), the excavated marine sediment was treated with cement and tested against the TCLP limits as provided in Table 2.16. The testing frequency was the same as that described in Section 10.5.1.14 of the approved EIA Report, which has been provided in Section 2.5.3.1. The treated marine sediment was tested against relevant engineering requirements to confirm their suitability as backfilling material for respective areas of different future uses. The UCS was also tested and defined based on respective engineering requirements. The backfilling works for all marine sediment excavated from the areas without ground improvement works by DCM were completed and there was no update during the reporting period. The following sections provide a summary on the volume of marine sediment excavated and treated for different areas.

2.5.3.2.1 Construction Berth at Area C5 of the Reclaimed Land Area

A construction berth was constructed at the eastern portion of newly reclamation area by Contract 3206. During the installation of casing, approximately 99m³ of marine sediment was generated and treated with cement stabilisation. The treated marine sediment was then tested against the TCLP limits and no exceedance was found. The backfilling of treated marine sediment was completed in 2022 and the backfilling location (a total of 117m³treated marine sediment) is shown in Figure 2.4. The sediment treatment and backfilling works were deemed to be completed.

2.5.3.2.2 T2 Foundation and Substructure Works

Approximately 60m³ of marine sediment was excavated and treated with cement stabilisation by Contract 3503. The treated marine sediment samples were collected and tested against the criteria for reuse of treated marine sediments with reference to the Universal Treatment Standards, which specify the TCLP test limits and passed the TCLP limits. All the marine sediment generated was treated and treated marine sediment backfilling work was completed in 2022. The backfilling locations of the treated marine sediment (a total of 72m³) are shown in Figure 2.4. The sediment treatment and backfilling works were deemed to be completed.

2.5.3.2.3 Approach Light Area

The marine sediment generated from Approach Light Area was covered by Contract 3303. The sampling works, treatment works, TCLP testing work and backfilling of the treated marine sediment were completed. The excavated marine sediment was about 2,251 m³and treated with cement stabilisation. The treated marine sediment samples were collected and tested against the TCLP limits and no exceedance was found. The backfilling was completed in 2022 and backfilling location of treated marine sediment (a total of 2,404m³) is shown in Figure 2.4. The sediment treatment and backfilling works were deemed to be completed.

2.6 Chinese White Dolphins

According to Sections 10.2.1.2 and 10.2.1.3 of the Updated EM&A Manual, CWD monitoring is required during the baseline, construction, post-construction and operation phases of the project. The construction phase monitoring of CWDs ended in December 2023 while the 12 months post-construction phase monitoring commenced on 1 January 2024. The construction phase CWD impact monitoring did not stop together with the construction phase water quality impact monitoring to collect a full-year set of monitoring data to facilitate the evaluation of CWD abundance on an annual basis. This arrangement was agreed upon by AFCD and EPD in December 2023. The commencement of CWD post-construction phase monitoring was approved by the EPD on 20 December 2023.

The aims of CWD monitoring during the construction period are:

● to monitor the potential shift in the CWD travelling areas and habitat use;

● to monitor the effectiveness of the HSF speed and routing restrictions to the CWDs;

● to provide a dataset compatible with the AFCD long-term monitoring, stratified in such a way as to allow the calculation of density and abundance for the different phases and to calculate the trends from these estimates; and

● to provide an assessment of how the project and cumulative effects may be impacting the CWDs.

This section summarises the results of the CWD construction phase monitoring effort over a 12-month period from January 2023 through December 2023, to gather information on the spatial and temporal distribution patterns as well as calculate density and abundance of CWD in western Hong Kong waters. Supplementary information collected focusing on northwestern Lantau waters, including habitat use and behaviours of CWD during the construction phase of the Project, has also been reviewed.

This reporting period is effectively the seventh full year of construction phase monitoring of CWDs. The overall monitoring programme commenced in August 2016, although there were no marine construction works in August and September 2016, and only localised sand blanket laying and DCM trial works from October to December 2016. This annual report reviews the construction phase monitoring data for 2023 and compares it with the construction phase monitoring data for the previous years.

CWD monitoring was conducted by undertaking vessel line-transect surveys, supplemented by land-based theodolite tracking surveys and Passive Acoustic Monitoring (PAM). The vessel line transects covered Northeast Lantau (NEL), Northwest Lantau (NWL), Airport West (AW), West Lantau (WL) and Southwest Lantau (SWL) at a frequency of two full surveys per month as proposed in Section 10.2.3.2 of the Updated EM&A Manual, which is consistent with the AFCD long-term monitoring programme (except AW). The locations of the CWD vessel survey transects are shown in Figure 2.5. Additional survey effort was collected on a voluntary basis at the same frequency of two surveys per month from Deep Bay (DB) (refer to Appendix F for the location of this additional survey), which is an area that historically had CWDs in the outer bay, to establish a full understanding of CWD abundance. All the DB data were considered supplemental and were only used for density and abundance estimation.

Density and abundance analysis made use of both conventional distance sampling (CDS) and a more sophisticated approach – multiple covariate distance sampling (MCDS) to estimate CWD abundance for the waters of Hong Kong. The additional analysis using MCDS is more time-consuming and labour-intensive than CDS as it uses information on environmental factors that are likely to affect detection probability (such as variables describing sighting conditions) and generally produces estimates with higher precision (i.e., lower variances and CVs) (Marques and Buckland, 2003 & 2004). However, datasets with small sample sizes (not unusual in marine mammal studies) can make it difficult or impossible to achieve model “convergence” in some MCDS analyses, and thus it is critical to always start each analysis with CDS methods (this also helps to determine the appropriate truncation distance and overall modelling approach).

Based on the vessel survey data, seasonal differences in dolphin density and use of the study area were examined, using the solar seasons (Winter: December-February, Spring: March-May, Summer: June-August, Autumn: September-November) and/or oceanographic seasons (Dry: October-March, Wet: April-September).

The travelling patterns in different areas were reviewed by using photo-identification of individual dolphins and their re-sighting locations, depicting the range use and cross-area movement of re-sighted individuals, where practicable. Travelling of CWDs in the north of Lung Kwu Chau were particularly supplemented with information from land-based theodolite tracking survey findings.

For the land-based theodolite tracking surveys, the monitoring frequency during the construction phase for marine works was one day per month at both the Lung Kwu Chau (LKC) station and Sha Chau (SC) station, as stipulated in Section 10.2.3.4 of the EM&A Manual. PAM was also deployed for the construction phase with data supplementing the results of both vessel and land-based surveys. For details on CWD monitoring and data analysis methodologies refer to Section 10.2.4 of the EM&A Manual. The locations of land-based survey stations are described in Table 2.18 and depicted in Figure 2.6. The location of the Passive Acoustic Monitoring device at A5 (with the coordinates of 22° 20.299’ N, 113° 53.871’ E) is shown in Figure 2.7.

Table 2.18: Land-based Survey Station Details

Stations	Location	Geographical Coordinates	Station Height (m)	Approximate Tracking Distance (km)
D	Sha Chau (SC)	22° 20’ 43.5” N 113° 53’ 24.66” E	45.66	2
E	Lung Kwu Chau (LKC)	22° 22’ 44.83” N 113° 53’ 0.2” E	70.40	3

Stations

Location

Geographical Coordinates

Station Height (m)

Approximate Tracking Distance (km)

Sha Chau (SC)

22° 20’ 43.5” N

113° 53’ 24.66” E

45.66

Lung Kwu Chau (LKC)

22° 22’ 44.83” N

113° 53’ 0.2” E

70.40

2.6.1 Action and Limit Levels

The Action Level and Limit Level for CWD monitoring were formulated by an action response approach using the running quarterly dolphin encounter rates (Encounter Rate by Number of Dolphin Sightings ‘STG’ and Encounter Rate by Number of Dolphins ‘ANI’) derived from baseline monitoring data covering six months from mid-December 2015 to June 2016, as presented in the CWD Baseline Monitoring Report. The derived values of Action and Limit Levels for CWD monitoring are shown in Table 2.19. Running quarterly encounter rates STG and ANI have been determined for each month since August 2016 to compare with the derived Action/limit levels for construction phase monitoring of CWDs. If persisting declines in the CWD running quarterly encounter rate values are determined month on month, an appropriate short-term response is then possible if the decline is shown to be related to 3RS construction activity.

Table 2.19: Derived Values of Action Level and Limit Level for Chinese White Dolphin Monitoring

	NEL, NWL, AW, WL and SWL as a Whole
Action Level⁽¹⁾	Running quarterly STG < 1.86 & ANI < 9.35
Limit Level⁽¹⁾	Two consecutive running quarterly (3-month) STG < 1.86 & ANI < 9.35

Notes: (1) Action Level and/or Limit Level will be triggered if both STG and ANI fall below the criteria

2.6.2 Summary of Monitoring Results

2.6.2.1 Summary of Vessel Line-transect Survey Monitoring Results

2.6.2.1.1 Survey Effort

During the reporting period from January 2023 through December 2023, surveys were completed in Northeast Lantau (NEL), Northwest Lantau (NWL), Airport West (AW), West Lantau (WL), and Southwest Lantau (SWL) survey areas. A total of around 5384.9 km survey effort was collected in this reporting period.

Around 97.2% (5234.8 km) of the survey effort was collected under favourable weather conditions (i.e. Beaufort 0-3 and visibility of approximately 1200 m or beyond), and can be utilised in analyses of encounter rates, density and abundance.

The breakdown of the survey effort by survey areas is tabulated in Table 1 of Appendix F. A detailed record of the survey effort data is also provided in Appendix F.

2.6.2.1.2 Sighting Distribution

During the reporting period, a total of 160 groups consisting of 542 CWDs were sighted in NWL, AW, WL and SWL survey areas during on-effort surveys. Apart from that, there was one off-effort sighting recorded. All 160 groups with 542 CWDs were sighted during on-effort surveys under favourable weather conditions (Beaufort 0-3 and visibility of approximately 1200 m or beyond). The off-effort sighting was excluded from analysis in the following sections. Breakdown of the sightings by survey areas are tabulated in Table 2 of Appendix F.

In NWL (including AW transects), CWDs were mainly sighted within and around the SCLKCMP, particularly in waters around Lung Kwu Chau. Compared to 2022, there were fewer sightings recorded in water around SCLKCMP. Several sightings were also recorded at the west of the existing Hong Kong International Airport. No sighting was recorded within the 3RS temporary works area.

In WL, CWD sightings were recorded on all transects. The sightings were distributed quite evenly over the entire survey area between Tai O and Fan Lau.

In SWL, sightings of CWD were scattered at most of the survey area except the waters to the east of the Soko Islands. There was a cluster of CWD sightings near Fan Lau while the number of CWD sighting declined significantly toward the Soko Islands and further to the eastern water.

No CWDs were recorded in NEL survey area. The sighting locations of CWDs during this reporting period are depicted in Figure 1 of Appendix F.

2.6.2.1.3 Encounter Rates

Two types of dolphin encounter rates were calculated based on the data collected during the reporting period. They included the number of dolphin sightings per 100 kilometers survey effort (STG) and total number of dolphins per 100 kilometers survey effort (ANI). The dolphin encounter rates were calculated by using survey data collected under favorable weather conditions only (Beaufort sea state 3 or below with favorable visibility). Encounter rate provides a short to medium term frequency method for monitoring and responding appropriately to changes in CWD abundance as project works progress (referring to Section 10.5.2.3 of the EM&A Manual). The two types of encounter rates provide an overall indication of changes in CWD numbers over time in western Hong Kong waters.

During the reporting period, the overall combined STG and ANI of CWDs (from NEL, NWL, AW, WL and SWL) in 2023 were 3.06 and 10.35 respectively. Dolphin encounter rates by survey area and a summary of monthly encounter rates are presented in Table 3 and Table 4 of Appendix F respectively. Compared by area, WL had the highest encounter rates STG and ANI amongst the survey areas, followed by SWL.

The temporal trends in 2023 fluctuated throughout the year and exhibited no distinctive seasonal patterns. The peak monthly STG and ANI occurred in February and March. This trend is rather different to previous years (e.g. 2019-2022) that the peak of monthly STG and ANI usually occurred in July. The trends of both monthly STG and ANI are presented in Figure 2 and Figure 3 of Appendix F respectively.

Running quarterly encounter rates STG and ANI data were determined for each month for comparison with the Action/Limit levels for construction phase monitoring of CWD. Although the running quarterly ANI has fallen below the Action Level in January, February, October, November, and December 2023, the overall Action Level was not triggered in this reporting period because the running quarterly STG of those months remained above the Action Level. However, it should be noted that the running quarterly STG of January 2023 has reached the lowest of the year (1.92) and it was very close to the Action Level. The Limit Level was not triggered during this reporting period as there were not any two consecutive running quarterly STG and ANI falling below the Action Level. The running quarterly STG and ANI from January to December 2023 are summarised in Table 4 of Appendix F. The graphical plots of running quarterly encounter rates of the current reporting year and the past reporting years are presented in Figure 2 and Figure 3 of Appendix F respectively.

2.6.2.1.4 Density and Abundance Estimation

Line-transect analyses to estimate the density and abundance of CWDs in Hong Kong waters during the reporting period were conducted using the same basic methods as in previous analyses. Although we experimented with Beaufort sea state as a co-variate, for 2023 the best estimate of abundance was obtained using Conventional Distance Sampling and a half-normal model with a cosine adjustment (effective strip width = 343 m). The detection function of 3RS CWD monitoring data of this reporting period is shown in Figure 4 of Appendix F and the various parameters of the 2023 estimates are shown in Table 5 of Appendix F. The overall abundance estimated for this reporting period (incorporating an entire year of data from all four seasons) was 40 CWDs (CV = 14.4%, indicating a good level of precision of <20%). This is somewhat above the estimate from the last three years from 2020 to 2022. For comparison, the 2022 estimate was 35 CWDs (CV = 15.8%), the 2021 abundance was 34 CWDs (CV = 16.5%) and the 2020 abundance was 32 CWDs (CV = 12.8%). As in all recent years, the area with the highest abundance and highest density in 2023 was WL (N=30; this has been consistent over the AFCD long-term records). NWL showed a very similar number of dolphins from the previous year (4 in 2023 and 3 in 2022), though SWL showed a decrease (from 10 to 5). NEL registered an abundance of zero, which has been the case in most of the last 10-12 years observed from both AFCD’s and 3RS’s monitoring. Overall, the number of dolphins was similar, though up somewhat, from last year. Though this may be indicative of the beginnings of a recovery, after dolphins moved away from the works area in past years, we are not yet seeing signs of a strong recovery in numbers. The drop in numbers since about 2010 is thought to be partly related to the impacts from the construction of the Hong-Kong-Zhuhai-Macao Bridge (HZMB). The HZMB impacts on dolphins would be expected to have been most severe between 2013-2016 (when the brunt of construction was occurring), and in fact, this time period saw a significant drop in numbers of dolphins in Hong Kong (see Jefferson 2018; Jefferson et al. 2023). Though this will require further examination, an increase since the completion of 3RS marine works is consistent with what was predicted in the 3RS EIA that further drops in CWD numbers during the 3RS construction, followed by a likely rebound towards pre-3RS construction levels in the period after completion of 3RS marine works.

It is worth noting that the 3RS EIA predicted significant impacts on CWDs (Mott MacDonald 2014), and a drop in numbers of dolphins in the area during the most intensive part of the 3RS construction phase was expected. Reclamation filling works were substantially completed in 2021 and some recovery after the main marine filling and reclamation works are finished was anticipated. However, this issue will need to be examined with more data over several years, as recovery may take some time. Cumulative impacts due to the 3RS project with other concurrent projects (e.g., reclamation works near Tung Chung in recent years, for instance) will become clearer as research progresses, and datasets grows.

In addition to estimating year-round abundance for each of the survey areas, a seasonal analysis was also conducted (the pooled dataset from all survey areas was used, as stratifying by both survey area and season would reduce the sample sizes that result in estimates with unacceptably low levels of precision) (refer to Table 5 of Appendix F). The autumn estimate was the lowest (N=31 dolphins), which is different from what has traditionally been the case for dolphin numbers in Hong Kong. The spring estimate showed the highest numbers (N=65 dolphins). Based on historical records, autumn has usually been the high season and spring the low season, so what we saw in 2023 was the opposite of this. This suggests that the environment is changing to the point that traditional patterns are being disrupted. The 2023 seasonal analysis shows that there was a marked influx of dolphins into Hong Kong during the transition from dry to wet seasons (especially in spring and summer months).

2.6.2.1.5 Quantitative Grid Analysis on Habitat Use

Quantitative grid analysis was conducted to examine the habitat use amongst the survey areas, both SPSE (no. of on-effort sightings per 100 units of survey effort) and DPSE (no. of dolphins per 100 units of survey effort) values for each 1 km² grid were calculated in all grids amongst all survey areas for the period from January 2023 to December 2023. SPSE and DPSE of the current reporting year and the previous reporting years are depicted in Figure 5 of Appendix F.

CWDs’ usage of waters in NWL in 2023 looks rather similar to that of 2022 with more usage of southwestern waters off Lung Kwu Chau, north to SCLKCMP and the west of existing HKIA. The most obvious difference in CWD’s usage in NWL compared to previous years is the first time that CWDs were absent from the western boundary of HKSAR in NWL.

The important dolphin habitats in WL survey area in 2023 are largely similar to 2022 with an increase in use around Peaked Hill. Grids with high SPSE and/or DPSE value(s) in WL were near Tai O, Yi O, Peaked Hill and Fan Lau.

In SWL, there was a decrease of CWDs’ usage at Soko Islands and Lo Kei Wan in 2023 again after a mild rebound last year (i.e. 2022), while the waters around Fan Lau and Fan Lau Tung Wan remained frequently used by CWDs.

Cumulative SPSE and DPSE values were also calculated by using the 3RS CWD monitoring data since mid-December 2015 and are depicted in Figure 6 of Appendix F. Grids in western waters of Hong Kong with higher dolphin density are restricted to waters off West Lantau, at Tai O, Yi O, Peaked Hill and Fan Lau.

2.6.2.1.6 Group Size

During the reporting period from January 2023 to December 2023, group size of CWDs ranged from one to 16 dolphins, with an average of 3.39, taking into account of all on-effort CWD sightings recorded. The average group sizes of NWL, AW, WL and SWL were 3.79, 2.33, 3.47 and 3.03 respectively. By four solar seasons, the average group size of CWDs was the highest in spring (4.38) but the lowest in winter (2.90). The summaries of the average group size of CWDs by survey area and by season are presented in Table 6 and Table 7 of Appendix F.

CWD sightings with small group size (i.e. 1 to 2 dolphins per group) and medium group size (i.e. 3 to 9 dolphins per group) were dominant in 2023 with around 48.8% and 48.1% of all on-effort sightings respectively. Five sightings, which accounted for 3.1% of all sightings, were large CWD groups with 10 or more dolphins per group.

Both small and medium CWD groups were generally sighted throughout the distribution range of dolphins in NWL, WL and SWL waters, except the observation that medium-sized groups were absent from the coastal waters of Tai Long Wan, Tong Wan near Shek Pik, and the eastern SWL survey area. Large-sized CWD groups were recorded in WL and SWL survey areas, particularly near Fan Lau. The sighting distribution of CWDs with different group sizes is illustrated in Figure 7 of Appendix F.

2.6.2.1.7 Activities and Association with Fishing Boats

Although vessel surveys do not provide the most unbiased information on the behaviour and activities of dolphins (due to the potentially disturbing presence of the vessel itself, and also the low vantage point of small vessels), nonetheless behaviour and activity data are still useful and are being collected from the vessel surveys.

During the reporting period, a total of 49, 9, 27 and 2 groups of CWDs were observed engaging in foraging, travelling, socialising and resting/milling activities, comprising of 31%, 6%, 17% and 1% of all on-effort CWD sightings respectively. The sighting locations of CWD groups engaged in different types of activities are depicted in Figure 8 of Appendix F while the percentages of different activities for each of the survey areas are shown in Table 8 of Appendix F.

In NWL, both foraging and socialising activities occurred within and outside SCLKCMP, and at the southwestern corner of the survey area.

In WL, foraging and socialising activities of CWDs occurred throughout the entire survey area. CWD sightings engaged in those activities occurred mainly at waters between Yi O and Peaked Hill, and also at Fan Lau. Travelling activities were mainly clustered between Yi O and Fan Lau, while one CWD sighting engaged in milling/resting activities was recorded at Yi O.

In SWL, the sightings with observed activities were scattered in the western water of the survey area, between Soko Islands and Fan Lau. Travelling activities mainly occurred near Soko Islands with one sighting occurring in the southern water of Fan Lau Tung Wan.

A total of 11 sightings of CWDs were observed associating with operating fishing boats, including gill netters (one group), pair trawler (one group), shrimp trawler (one group), and purse seiners (eight groups), accounting for 6.9% of all on-effort sightings in 2023. CWDs’ association with operating fishing boats in 2023 showed a minor drop compared to that of last year (8.1% in 2022).

Observations of CWD association with operating fishing boats were scattered in WL, SWL and NWL. Association with gill netters and a shrimp trawler were observed near Tai O and Peaked Hill respectively in WL. The four sightings in association with purse seiners in WL were observed in water between Tai O and Peaked Hill. While in SWL, associations with operating purse seiners were mainly observed in coastal water between Fan Lau and Tong Wan. Another sighting in association with pair trawlers was observed in the northeast water of SCLKCMP in NWL. The sighting locations of CWD groups associated with operating fishing boats are depicted in Figure 9 of Appendix F.

2.6.2.1.8 Mother-calf / Mother-unspotted Juvenile Pairs

During the reporting period, a total of 30 sightings were observed of mother-and-unspotted calf (UC), mother-and-unspotted juvenile (UJ) and/or mother-and-mottled pairs, which accounted for about 18.8% of all on-effort sightings of 2023. The sighting number was similar to that of 2022 (31 sightings). For different survey areas, the percentages of sightings with mother-calf pairs in NWL, AW, WL and SWL were 35.7%, 33.3%, 18.9% and 9.4% respectively. These percentages were calculated by dividing the number of sightings with mother-calf pairs of a survey area by the total number of on-effort sightings of that survey area.

The abovementioned 30 sightings included five pairs of mother-and-UC and 31 pairs of mother-and-UJ. According to the results of photo-identification, a total of six mother-calf pairs were successfully identified from these 30 sightings.

Most of the sightings with a mother-calf pair were recorded in WL between Tai O and Fan Lau. In NWL, one sighting with mother-calf pairs was recorded in SCLKCMP while other sightings were recorded to the west of the existing airport. In SWL, three sightings with the presence of mother-calf pairs scattered in waters between Fan Lau and the Soko Islands. The sighting distribution of mother-calf pairs is depicted in Figure 10 of Appendix F.

2.6.2.1.9 Photo Identification – Summary

In 2023, a total of 18 newly identified CWD individuals were added to the photo-identification catalogues, including four animals added to NL catalogue and 14 animals added to WL catalogue. One animal, namely SLMM075 was confirmed to be a duplicate of another individual (i.e. NLMM041), which had already been identified previously. Therefore, all records under this duplicate were transferred to the records under NLMM041.

In 2023, a total of 116 CWD individuals were identified for altogether 359 times from all sightings. Amongst these 116 CWD individuals, 26, 62 and 28 belonged to NL, WL and SL catalogues respectively. There were 69 individuals (around 59.5%) that were sighted more than once. Twenty-six of these 66 re-sighted individuals were sighted five times or more.

The most frequently re-sighted animals in 2023 were SLMM003, SLMM037, SLMM044 and WLMM056. They were all sighted 11 times, followed by WLMM007 and SLMM010 (being re-sighted 10 times and 9 times respectively). SLMM037 was also the most frequently re-sighted animal of the previous reporting year (i.e. being sighted for 12 times in 2022). Since the establishment of the photo-identification catalogue, the most frequently re-sighted animal is SLMM014 which has been sighted 70 times, followed by SLMM003 and SLMM037 (each being sighted 64 times), SLMM010 (sighted 57 times) and WLMM001 (sighted 56 times). There are a few more animals including NLMM013, WLMM007, WLMM027, WLMM028, WLMM043, WLM056, WLMM071, WLMM079, WLMM114, WLMM131, SLMM002, SLMM007, SLMM012, SLMM023, SLMM031, SLMM049 and SLMM052, that have been sighted 30 times or more.

Twenty-eight animals that were frequently using Hong Kong waters in previous years (with 10 or more re-sighting records since the commencement of the monitoring in mid-December 2015) have disappeared from our sighting records in 2023 (note that these dolphins may still be using Hong Kong waters, but may have not been detected from our surveys). These animals are NLMM002, NLMM004, NLMM006, NLMM010, NLMM018, NLMM019, NLMM043, SLMM011, SLMM012, SLMM015, SLMM017, SLMM028, SLMM045, SLMM053, WLMM006, WLMM008, WLMM009, WLMM013, WLMM049, WLMM052, WLMM054, WLMM060, WLMM076, WLMM078, WLMM081, WLMM090 ,WLMM107 and WLMM131. Some of these individuals (i.e. NLMM002, NLMM004, NLMM006, NLMM010, NLMM018, NLMM019, NLMM043, SLMM011, SLMM015, SLMM017 SLMM028, SLMM045, SLMM053, WLMM006, WLM008, WLMM009, WLMM054, WLMM060 ,WLMM078, WLMM090 and WLMM107) have not been seen in Hong Kong waters for two or more years. We could not confirm if these animals were occurring elsewhere in mainland waters, or if some of them have already passed away.

On the other hand, some dolphins (with 10 or more re-sighting records since the commencement of the monitoring in 2015) that disappeared from previous years have returned to Hong Kong waters in 2023. These dolphins include NLMM001, NLMM020, NLMM021, SLMM022, WLMM030, WLMM062 and WLMM086. Amongst these animals, NLMM041 showed the most noticeable return to Hong Kong waters in 2023. This animal was first identified in 2016 and was regularly seen every year between 2016 and 2019, then disappeared from our sightings between 2020 and 2022, followed by the return in 2023 with six re-sightings.

In previous years, special attention had been given to SLMM028, which had a severe injury in 2018. It showed good signs of recovery from its serious injury with normal foraging behaviour recorded 2019 and 2020, however, it was not sighted during vessel surveys for three years since 2021. Continuous attention will be given to SLMM028 in 2024.

A summary of the photo-identification records of CWDs is presented in Table 9 of Appendix F.

2.6.2.1.10 Photo Identification – Range Use of Identified CWD individuals

SLMM003, the most frequently re-sighted animal in 2023 and also the 2^nd most frequently re-sighted animal since mid-December 2015, continued to occur frequently in WL and SWL waters. Following the shrinking range use in both areas observed in 2022, SLMM003’s range use remained similar to that of 2022, ranging from Yi O in WL to Fan Lau Tung Wan in SWL.

SLMM037, the most frequently re-sighted animal in 2023 and also the 2^nd most frequently re-sighted animal since mid-December 2015, continued to occur frequently in WL and SWL waters like SLMM003. It continued to occur from Yi O in WL to Soko Islands in SWL.

SLMM044, another most frequently re-sighted animal in 2023, continued to occur in WL and SWL waters. The range use of SLMM044 remained similar to 2022 with a mild eastward extension in SWL.

WLMM056, another most frequently re-sighted animal in 2023, continued to occur in WL and SWL waters. The range use of WLMM054 in northern part of WL shrank to waters between Tai O and Yi O when compared to the range use of 2022.

WLMM007, the 2^nd most frequently re-sighted animal in 2023 occurred in WL and SWL waters much more frequently than in 2022. Its range use shrank a bit from Tai O to Yi O in WL and from Fan Lau Tung Wan to Fan Lau in SWL compared to earlier years (i.e. 2015 to 2021)

SLMM010, the 3^rd most frequently re-sighted animal in 2023 and the 3^rd most frequently sighted animal overall, occurred much more in WL and SWL waters than in 2022. Its range use in NWL and WL shrank from the waters between Sham Wat to Fan Lau in earlier years (i.e. 2015 to 2021), to the waters between Peaked Hill to Fan Lau in 2023.

The sighting locations of SLMM003, SLMM037, SLMM044, WLMM056, WLMM007 and SLMM010 are depicted in location maps under Figure 11 of Appendix F, which provide the indicative distribution range use of representative individuals recorded for the 3RS CWD monitoring.

2.6.2.1.11 Photo Identification – Cross-area Movement

Amongst the 69 individuals that were re-sighted more than once in 2023, 40 individuals showed cross-area movement between survey areas. This accounted for about 34.5% of all 116 identified animals in 2023. Amongst these 40 animals, 12 animals (30.0%) were re-sighted in both NWL (including AW) and WL, 25 animals (62.5%) were recorded in both WL and SWL. There were three animals (7.5%) namely NLMM016, NLMM027and WLMM028 which were recorded occurring in all three main survey areas (WL, SWL and NWL) in 2023.

2.6.2.1.12 Photo Identification – Residency Pattern

The residency patterns of the dolphin individuals identified under this monitoring programme have been examined. For residency pattern analysis, both seasonal and annual occurrence patterns of identified CWD individuals with 15 or more re-sighting records (since the establishment of the photo-identification database) were carefully examined. “Residents” are defined as individual dolphins that were regularly sighted for at least three consecutive years, while “Visitors” are individuals that were intermittently sighted during the past years since the establishment of the photo-identification database. Seasonal occurrence patterns were also examined to distinguish individuals that occurred year-round (i.e. individual dolphins sighted in all four seasons of a year in at least one of the last two years) or seasonally (i.e. individual dolphins that occurred only in certain season(s) of a year). Therefore, there are four combined classifications of the residency pattern of an individual dolphin theoretically. These four classifications are:

● “Year-round resident” – dolphin which appears in Hong Kong waters in all four seasons of a year in at least one of the two last years and it was sighted for at least three consecutive years

● “Seasonal resident” – dolphin which appears in Hong Kong waters only in certain season(s) of a year and it was sighted for at least three consecutive years

● “Year-round visitor” – dolphin which appears in Hong Kong waters in four seasons of a year in at least one of the two last years and it was NOT sighted for at least three consecutive years

● “Seasonal visitor” – dolphin which appears in Hong Kong waters only in certain season(s) of a year and it was NOT sighted for at least three consecutive years

Up to year 2023, photo-identification records of 64 dolphin individuals that have at least 15 re-sightings since the establishment of the database were examined. There are 14 animals namely SLMM002, SLMM003, SLMM007, SLMM010, SLMM014, SLMM023, SLMM037, SLMM044, SLMM052, WLMM001, WLMM007, WLMM043, WLMM056 and WLMM079 being defined as year-round residents while 49 animals were considered as seasonal residents. Only one individual, namely SLMM011, out of these 64 individuals is considered as a visitor to Hong Kong waters. However, it should be noted that the low number of dolphins being classified as visitors at present is mainly because of difficulty for visitor dolphins to meet the minimum requirement of at least 15 re-sightings with their intermittent sighting records. The details of the residency pattern of these 64 animals are shown in Appendix F.

2.6.2.2 Summary of Land-based Theodolite Tracking Monitoring Results

In this reporting period, land-based surveys commenced on 17 January 2023, and concluded on 27 December 2023. A total of 24 days and 144 hours of land-based theodolite survey effort were accomplished, including 12 days and 72 hours from LKC and 12 days and 72 hours from SC (Table 10 of Appendix F for summary). A total of 7 CWD groups were tracked from land, for a total of 2.45 hours, all from the LKC station (Table 10, Figure 12 Appendix F). CWD sightings were all within 3.3 km of the LKC tracking station. The number of CWD groups sighted from LKC per survey hour was 0.10, compared to 0.07 in 2022, 0.22 in 2021, 0.29 in 2020, 0.33 in 2019, 0.77 in 2018, and 0.89 in 2017. No CWDs were observed from SC. No calves were recorded off LKC during theodolite tracking surveys.

After raw data were filtered, 6 CWD group tracks off LKC fit criteria for movement pattern analyses. From the tracks that fit the criteria, 10 10-minute short-track segments could be extracted for potential analyses. Based on this information, sample sizes were simply too low for appropriate statistical analyses, and therefore the present data are summarised to show potential trends. Due to low sample size, all data were used to summarise diurnal, annual, and group size patterns and behavioural state activity. Filtered standardised short-track segments were used to summarise movement patterns, similar to 2020, 2021 and 2022 data analysis.

2.6.2.2.1 Time of Day

The diurnal pattern of CWDs was calculated by dividing the total tracking time of CWD groups (prior to filtering short-track data) by the total effort per hour block, and depicted in Figure 13 of Appendix F. Off LKC, the highest proportion of CWD tracking time per hour of effort was recorded during the 1100 hour block (9.5%) and the 1200 hour block (10.4%). A small proportion of tracking time per hour of effort was recorded during the 1300 hour block (0.5%). CWDs were not tracked during the 0800, 0900, 1000, 1400, or 1500 hour blocks.

2.6.2.2.2 Time of Year

CWDs were observed from LKC during winter (January and December) and summer (July and August) months, and during both dry and wet seasons of 2023, as depicted in Figure 14 of Appendix F. In 2022, 2021 and 2020, CWDs were observed most often during the dry season and during winter; however, CWDs were observed during more months and also observed during the wet season in previous years.

2.6.2.2.3 Group Size

The mean group size of CWDs off LKC prior to filtering tracks was 2.7±2.2, ranging from singletons to a maximum group size of 7 dolphins (Table 11 of Appendix F). In comparison, the group size was 2.2±1.6 (range 1-5) in 2022, 3.0±1.8 (range 1-7) in 2021, 1.8±0.9 (range 1-4) in 2020, 1.9±1.2 (range 1-6) in 2019, and 2.6±1.5 in 2018 (range 1-8).

Based on proximity to the SCLKCMP boundary, the mean CWD group size was 3.8±2.5 (n=4, range 1-7) when crossing the marine park boundary. A single group of 2 individuals was observed outside the SCLKCMP boundary and two separate single individuals were observed inside the marine park. The sighting distribution of CWDs relative to group sizes within the SCLKCMP, crossing the SCLKCMP boundary and outside the SCLKCMP are represented in Figure 15, Figure 16 and Figure 17 of Appendix F respectively.

After filtering tracks to assign vessel presence/absence, the mean group size of CWDs was 2±1 (range 1-3) when no vessels were present and 4±3 (range 1-7) when vessels were present (Table 11 of Appendix F).

2.6.2.2.4 Behavioural State

The unknown behavioural category (22%, n=39) was excluded from the following summary of behavioural states. CWDs were recorded foraging (62%) and travelling (38%) during theodolite tracking time, prior to filtering tracks (Figure 18 of Appendix F). Milling, resting and socialising behaviour were not recorded off LKC in 2023. Milling and socialising were also not observed off LKC in 2022.

Within the boundary of the SCLKCMP, observed CWD behavioural states included foraging (94%) and travelling (6%) (Figure 19 of Appendix F). Outside of the SCLKCMP, the only observed CWD behavioural state was foraging (100%), whereas the only observed behavioural state observed outside of the park in 2022 was travelling. CWDs crossing the SCLKCMP boundary were recorded foraging (57%) and travelling (43%).

2.6.2.2.5 Movement Patterns and Vessel Activity

Plots of vessels, including high-speed ferries, and CWDs continue to show overlap in habitat off LKC throughout the year (Figure 20 of Appendix F).

Off LKC in 2023, 206 vessels were recorded during theodolite tracking surveys. Three vessels, including a construction boat, a government boat, and a fishing boat were recorded within 500m of dolphins (based on filtered short-track segments). Mean speed, reorientation rate and linearity for CWDs in the presence and absence of vessels are detailed in Table 12 of Appendix F. Due to extremely small sample sizes (no vessel = 3; high speed ferry = 0; other vessels =7), statistical analyses were not possible; and it is cautioned that the apparent high CWD swim speed of "no vessel" vs. the much lower speed of "other vessel" cannot be assessed as a meaningful difference.

2.6.2.2.6 Summary of findings of Land-based Theodolite Tracking Monitoring in 2023

● Similar to 2020 through 2022, 2023 provided few samples and the inability to conduct robust statistical analyses as low numbers make most statistical analyses impossible. There is a slight increase in the number of CWDs observed per hour of effort in 2023 compared to 2022, but numbers of CWDs are still lower compared to years prior to 2019. The overall statistics of number of animals in Hong Kong waters showed a slight increase (see section 2.6.2.1.4).

● The number of CWD groups sighted from LKC per survey hour was 0.10, compared to 0.07 in 2022, 0.22 in 2021, 0.29 in 2020, 0.33 in 2019, 0.77 in 2018, and 0.89 in 2017.

● CWDs were observed most often during the late morning and early noon hours (1100, and 1200 hour blocks). This pattern was similar to 2022 and 2021, during which CWDs were observed in the late morning and early afternoon hours (1100, 1300, and 1400 hour blocks) but differed from 2020, when CWDs were observed most often during the 0900 morning hour block and almost none observed after noon. Again, it is cautioned that with so few data in recent years, such hourly sightings cannot be assessed as true diurnal patterns.

● CWDs were observed only during the winter and summer seasons, compared to the highest percentages of CWDs observed during the autumn and winter seasons in 2022 (similar to 2021, 2020, and 2019).

● In 2023, CWDs were recorded in both dry and wet seasons, compared to only the dry season in 2022. In 2021 and 2020, although CWDs were recorded during both oceanographic seasons, they were observed most often during the dry season.

● The maximum CWD group size in 2023 was 7 individuals, the same as 2021, compared to a maximum of 5 individuals in 2022, 4 individuals in 2020, 6 individuals in 2019, and 8 individuals in 2018.

● Overall, waters off Lung Kwu Chau were primarily used for travelling and foraging, which is similar to the high percentages of travelling and foraging observed in 2022, 2021 and 2020.

● CWD groups were observed inside, outside, and crossing the SCLKCMP boundary, and group sizes were larger crossing the park boundary, which differs from recent years when group sizes were larger outside of the park boundary (2022) and larger inside the park boundary (2021). The earlier caveat holds of small sample sizes making statistically-valid comparisons not possible.

● Foraging and travelling were observed for CWDs within and crossing the SCLKCMP boundary, while only foraging was observed outside the SCLKCMP boundary.

● Only three vessels were recorded within 500m of CWD groups in 2023, based on filtered short-track segments, which is probably in large part due to low sample size, but could also reflect potential CWD avoidance of vessels off LKC, as noted previously.

● There were no sightings of CWDs off Sha Chau during land-based theodolite surveys in 2023 (the same as 2022, 2021 and 2020).

2.6.2.3 Summary of Passive Acoustic Monitoring (PAM) Results

2.6.2.3.1 Dolphin Detection per Day

During 30 December 2022 to 4 January 2024, there were five deployment periods of F-POD and C-POD at position A5 for PAM (with the coordinates of 22° 20.299’ N, 113° 53.871’ E). During the deployment period, CWDs were detected at Location A5 with a total of 116 true dolphin Detection Positive Minutes (DPM), as summarised in Table 13 of Appendix F. Dolphins were detected on 43 of 375 days with recording effort (Figure 21 of Appendix F).

The activity of CWDs was represented by the percentage of Detection Positive Days (DPD) over total logged days (i.e. DPD %). Over the five deployment periods, DPD % ranged from 4.61% to 27.94%, while the presence of CWD was detected in overall 11.47% of the logged days (as summarised in Table 13 of Appendix F). Low dolphin activity was generally recorded from PAM at Location A5 throughout deployment periods in 2023. While comparing with the previously reported values, the overall dolphin occurrence during this reporting period represents a slight decrease in detection rates compared to year 2022 (Table 14 of Appendix F).

In terms of solar season, as illustrated in Figure 21 of Appendix F, the DPM recorded at winter months were the greatest among all seasons, which accounted for more than half of the total DPM recorded throughout the deployment periods. In spring, the CWD detections dropped and accounted for around a quarter of the total DPM. The CWD detections further decreased in summer and remained low throughout the season. Similar level of CWD detections remained throughout the autumn until the winter in late 2023, with DPM only recorded occasionally on a few days.

2.6.2.3.2 Dolphin Diel Pattern

Dolphin detection rates at A5 were overall greater at night than during daytime, with a peak in detections in the 0300 time block and remaining high in the hour block 2100 (as indicated in Figure 22 of Appendix F). Relatively high dolphin acoustic detections were also recorded during 1700 to 2300 comparing to mid-night hours (except hour 0300) and daytime hours. The higher night-time detection rate observed during this monitoring period is similar to the diel pattern in dolphin detections observed throughout Hong Kong waters, with higher numbers of detections during night-time and fewest detections in the middle of the day (Munger et al. 2016). In spring, the peak detection hour was at 1900 while peak detection hour in summer was 2300 (Figure 23 of Appendix F). In autumn, there was a peak detection at hour 0300 while peak detection hours in winter were 1700 and 2300. A similar diel pattern of more night-time detections than daytime detections was observed throughout the four solar seasons, but it was less apparent in summer when only few detections were recorded.

2.6.3 Discussion on CWD Monitoring Results

CWD monitoring by vessel surveys has been conducted as required during the construction phase from 2015 to 2023, with substantive marine works largely completed since 2021. Supplementary surveys including land-based theodolite tracking and underwater passive acoustic monitoring have provided additional information (such as habitat use of CWDs during day and night) for facilitating a review of the effectiveness of mitigation measures proposed and any need for adaptive management measures. Although the scaled back theodolite monitoring has provided interesting supplemental information, there is lack of adequate survey data for conducting robust analysis. In addition to interpreting monitoring data in relation to identifying any project impacts, the interpretation of data from all three monitoring types can also assist in examining the kinds of issues that need to be considered for management and conservation of CWD in Hong Kong.

2.6.3.1 Vessel Line-transect Survey and Photo-identification

From the CWD vessel-based monitoring data, the estimate of overall abundance for 2023 was 40 dolphins, which is somewhat higher than the year before, with a CV of 14.4% (which indicates a good level of precision). It is not surprising to see that the estimate of total dolphin numbers in Hong Kong was a bit higher than the previous year’s estimate (35 dolphins in 2022, CV = 15.8%), though a change from one year to the next should never be taken as an indication of long-term trends. Although CWD estimates in Hong Kong were relatively stable or increased somewhat from 2016 to 2018 (Jefferson 2018; Jefferson et al. 2023; 3RS Annual EM&A Report 2018), Hong Kong waters have been showing an overall declining trend in dolphin numbers over much of the last dozen years or so (see Jefferson 2018; Jefferson et al. 2023), and the 3RS EIA predicted shifting of dolphins away to waters outside Hong Kong and a significant effect on numbers in Hong Kong during intensive periods of construction (EIA Report Section 13.9.2). From 2018-2021, there was seawall construction and marine filling in the 3RS works area, as well as reclamation works for the Tung Chung New Town Extension concurrently in North Lantau waters (note that the changes in the size of the different survey areas over the past few decades have been taken into account in the line-transect analysis for this year, with the total area of the NWL area being reduced to account for this loss of potential habitat). Year 2021 was still in the phase of construction that had the most impact on dolphins, though 2022-2023 is now beyond that period. Since the major reclamation work for the 3RS project concluded in 2021, some level of recovery would be expected, and some early signs of that appear to be evident in the data. However, several additional years of similar survey effort will be needed to examine this issue thoroughly, and we should not yet conclude that recovery has begun. In fact, some time delay in seeing an increase in dolphin numbers would be reasonable to expect. In particular, significant recovery would not be expected until after the NLMP comes into effect, which is scheduled to happen in the near future.

Within NWL waters, CWDs have recently been mostly found around the Castle Peak and Lung Kwu Chau areas. A total of 17 dolphin sightings were made (in favourable weather conditions) in NWL including AW transects in 2023, indicating that, while dolphins largely moved away from this area in 2020-2021, they may be starting to return. The seasonal analysis showed that during spring/summer, dolphin numbers are somewhat higher in Hong Kong waters. The 2023 seasonal range is 31 to 65 dolphins. The autumn estimate was the lowest (31 dolphins), while the spring estimate was the highest (65 dolphins), and this indicates that, despite the overall reduction in the average number of dolphins using Hong Kong waters in recent years, there are well over 60 dolphins estimated to be present in Hong Kong in the spring months. The main concern is that dolphin numbers in NWL have decreased quite significantly in the past decade, from around 100 to less than 20 (see Jefferson 2018; Jefferson et al. 2023). Some good news is that in WL and SWL dolphin numbers have remained similar to those in previous years. Past decreases suggested that construction activities in other areas of western Hong Kong waters (which, besides the 3RS works, includes IWMF works at Shek Kwu Chau) and other factors that are affecting dolphins north of Lantau Island may also be affecting their use of the waters south and west of Lantau Island. The potential for cumulative and far-ranging impacts from projects in specific areas is not well understood, and should be investigated in future monitoring efforts (including both those in relation to this project, and other studies outside the 3RS monitoring effort). This would be a particularly acute concern for the West Lantau area, which is known to represent the highest-density area for CWDs (and has since monitoring efforts began in the mid-1990s) and although not heavily impacted by marine construction in the past few years, the area has nonetheless shown evidence of a decrease in CWD numbers.

In earlier years, concerns had been expressed by some interested stakeholders that dolphin numbers in NWL may have decreased specifically due to hypothesized negative impacts from the re-routing of high-speed ferries (HSFs) to the Speed Control Zone (SCZ) north of Lung Kwu Chau. The analysis covering the entire first year post-SCZ (2016) provided an estimated abundance of 15 dolphins for NWL (refer to the 2016 annual report). The estimate for 2017 for the same area was 14 dolphins. The 2018 estimate was substantially higher at 22 dolphins. Therefore, the drop in 2019 to 8 dolphins was not likely due to the effects of the SCZ, which had been in operation for several years, but was more likely due to relatively more construction works for the 3RS and concurrent activities (such as changes in overall vessel traffic) in NL waters, or due to other unknown reasons. This belief is further bolstered by the fact that daily HSF trips were down substantially to single-digits in 2020 to 2022 due to COVID-19 impacts, and yet CWD numbers continued to decrease. Whatever the reasons for the fluctuations in numbers of dolphins in the NWL area, there is still no evidence that the SCZ has had any negative impacts on the dolphins.

Concerns were expressed in the 3RS EIA about the potential impacts on the travel corridor/area between both the 3RS Project Area and SCLKCMP, and between CWD hotspots in NWL, NEL and WL, and the concern on the effectiveness of implementing the SkyPier HSF route diversion in alleviating the impacts on CWD travelling areas. Increased CWD sightings from vessel surveys in NEL area during 2018 suggested that a slight rebound in the use of these travel areas by CWDs may have occurred, however this increase has not continued in 2019-2023. HZMB impacts were likely most severe during the period from 2013 to 2016 when construction works were ongoing (a period which saw an overall decline in CWD numbers in Hong Kong – Jefferson 2018), and the increase in CWD numbers seen in 2018 may have been the initial stages of recovery from that period of more intensive HZMB construction impacts. It is likely that the 3RS construction works and other concurrent activities in NL waters in 2019 onwards may have caused dolphins to again move away from these areas, as predicted in the 3RS EIA (Section 13.9.2). Nevertheless, it is noted that previous experience suggests that when construction is completed, and the new marine park goes into effect, a rebound in numbers can again be expected (see Jefferson 2018). Data since 2018 indicate that the travelling areas are still being used, although at a lower level. It should also be kept in mind that dolphins tend to move through these areas relatively quickly and do not generally spend as much time milling as they do in the main foraging/socialising areas, which may further reduce the chance of dolphin sightings.

Regarding the results of photo-identification work, a total of 116 CWD individuals were identified for altogether 359 times from all sightings in 2023, with 69 individuals (around 59.5%) sighted more than once. Amongst the 69 individuals that were re-sighted more than once in 2023, 40 individuals showed cross-area movement between survey areas. This accounted for about 34.5% of all 116 identified animals in 2023. Three animals were recorded occurring in all three main survey areas (WL, SWL and NWL). After a remarkable increase in cross-area movement involving NWL from eight individuals in 2020 to 21 individuals in 2021 followed by a drop to 12 individuals in 2022, the number of identified individuals with cross-area movement involving NWL slightly increased to 15 individuals in 2023. The most frequently re-sighted animals in 2023 were SLMM003, SLMM037, SLMM044 and WLMM056, which were all sighted 11 times. Fourteen identified dolphins were considered as year-round residents of Hong Kong waters in view of their occurrence pattern in all seasons for consecutive years.

2.6.3.2 Land-based Theodolite Tracking

In the accumulation of 12 days and 72 hours of theodolite surveys at the station on LKC in 2023, a total of 7 CWD groups were tracked, and ten groups fit the criteria for movement pattern summary. Due to low sample sizes, as in 2022, 2021 and 2020, we were unable to conduct robust statistical analyses. While there are not enough data for robust statistical analyses of behaviours of CWDs relative to group sizes, presence of vessels, etc., it is clear that habitat use off LKC continues to be less when compared to pre-2019 activity. The present data are summarised to show the apparent present situation and potential trends. During the total of 12 days and 72 hours of theodolite surveys off SC in 2023, no dolphins were observed or tracked, similar to previous years (2018 to 2022).

The sighting rate (CWD groups observed per survey hour) off LKC in 2023 (0.10) reflects a slight increase compared to 2022 (0.07), which is congruent with the small apparent increase in overall numbers based on 2023 vessel surveys. We caution that this potential increase is so small that it is not likely to be biologically significant when comparing this and recent years. However, if the apparent increase in trend continues for several more years, we may be able to assess that dolphins are indeed using the described area more than in recent years. We also caution that shore-based and acoustic-based (see below) data do not supply estimates of numbers of animals using a certain area. They are instead valuable for assessments of group sizes, behaviors, and movement patterns. See Section 2.6.4.3 (below) for further discussion.

In 2023, all dolphin records were within 3.3 km of the LKC station. Survey data show that the heaviest use of waters north of the SCLKCMP by CWDs was in the late morning and noon hour blocks. CWDs were tracked during both the dry and wet seasons, and in summer and winter seasons. Maximum CWD group size was 7 dolphins, and no calves were observed.

Overall, waters off Lung Kwu Chau continue to be important habitat used for foraging and travelling. Only three vessels were recorded within 500m of CWD groups, which may be due to low sample size or reflect potential CWD avoidance of vessels off LKC. It is hoped that dolphins will return to this former CWD “hotspot” area north of the SCLKCMP as 3RS marine activities have wound down, and yet the shore-based monitoring for use of habitat in this important area is not going to continue in post-construction phase monitoring, which has been agreed by the EPD and fulfilled the requirements under the EM&A Manual.

2.6.3.3 Passive Acoustic Monitoring

The PAM data continue to provide useful information on patterns of dolphin vocalization at night, which has previously been unavailable to us and could not be recorded during the land-based survey conducted during daytime at south of Sha Chau. The diurnal detection of clicks showed a consistent pattern of higher levels in late evening and at night compared with the day, which may be indicative of increased use of echolocation by dolphins during hours of darkness.

The PAM data provide evidence that dolphins are still using the area around south of Sha Chau. In 2023, dolphins were present with especially high incidence during winter (January to February), and less so in other seasons. This lack of detections may represent a reduction or absence of dolphin usage, but it could also be related to high ambient noise levels that reduced the detectability of dolphin signals.

Dolphins were detected more frequently during night-time hours than during the day, and this may be related to nocturnal foraging behaviour. This has been a general trend throughout PAM monitoring in most parts of Hong Kong (Munger et al. 2016). It is also possible that at least a portion of this diel trend is related to dolphins utilising this area more intensively at night than in daytime, because of decreased industrial activity at night.

The PAM in 2023 represents a slight decrease in overall dolphin detection from 2022 (i.e. 11% of days with dolphin in 2023 and 14% of days with dolphins in 2022) but is higher than that in 2021 (i.e. 7% of days with dolphins in 2021). However, it is still relatively lower than the previous years in terms of percentage of days with dolphin detections (i.e. 22% of days with dolphins in 2020 and 38% of days with dolphins in 2019), echoing with the overall decrease of CWD occurrence in North Lantau waters as mentioned above. Nevertheless, the seasonal and diel detection patterns observed in 2023 suggest that dolphins continue to use the Sha Chau area especially in winter, and then primarily at night and in conditions when visual observation is not feasible. This also supplements the land-based theodolite tracking result where no CWD groups have been tracked from Sha Chau theodolite station since 2020.

2.6.4 Conclusions of CWD Monitoring Results

With reference to the aims of construction phase CWD monitoring described in the EM&A Manual (Section 10.2.1.2-4), the key findings of CWD monitoring in 2023 are summarised as follows.

2.6.4.1 Effects on the Potential Shift in CWD Travelling Areas and Habitat Use

The latest monitoring data indicate an increase in overall numbers, but mixed trends in use of areas within Hong Kong waters in 2023, as compared to the previous year. The main area of increased use was West Lantau, which showed a substantial increase from the previous year (from 22 to 30 CWDs). As expected and predicted in the 3RS EIA, dolphins likely shifted their activities away from the 3RS construction activities as well as increasing marine works for the Tung Chung New Town Extension project in 2019-2021. Nevertheless, they still used Hong Kong’s western waters (primarily SWL and WL) for important ecological activities like foraging and resting, despite the disturbance. Whether a possible increase observed in 2021-2023 is indicative of the start of a long-term dolphin recovery in Hong Kong remains to be seen. An important question now is how much recovery there will be when the marine construction activities end in this area, and the new marine park comes into effect. Future monitoring efforts beyond the construction phase will help to track this.

2.6.4.2 Effectiveness of the HSF Speed and Routing Restrictions to the CWDs

As detailed above, we now have eight years of data from the period since the SCZ was implemented, and the information available from both the vessel-based and land-based monitoring indicates that dolphin use of the NWL area has fluctuated from year to year (ranging from 1 to 22 dolphins), with a period of initial increase after the SCZ was put into effect. Due to COVID-19 effects, 2020, 2021 and 2022 were years of significantly decreased HSF activity in general, including in the SCZ area, and yet there was still a reduction in the use of NWL. Therefore, the evidence suggests that the SCZ is not impacting dolphin use of this area, and at the same time, is likely reducing the chances of dolphins being hit by vessels travelling at high speed. Daily SkyPier HSF trips were down substantially from 2020 to 2022 due to COVID-19 (refer to Section 2.7 and Table 2.27), thus there was no substantive new data on CWDs tracked near HSFs over the monitoring period. Observations in 2021-2023 are line with those previous assessments.

Waters around Lung Kwu Chau have historically been a significant year-round habitat, especially for foraging, though 2020 saw a very large decline in use of this area by CWDs. There is no evidence that the observed decline in dolphin use of the HSF SCZ around Lung Kwu Chau was due to ferries being re-routed to that area with slower speeds at the end of 2015. The decline in numbers of dolphins in NWL area is not considered to be linked to HSF re-routings and the SCZ, and the apparent increase in 2021-2023 is considered encouraging.

2.6.4.3 Trends in Long Term Monitoring Data

From vessel surveys conducted, though there appears to be a continuous uptick in 2022-2023 following 2021, CWD use of Hong Kong waters was down significantly from the early 2000s. West Lantau waters are still being used as the most important habitat in Hong Kong, as has been the case since CWD monitoring in Hong Kong first started in 1995/1996. It is estimated that 40 dolphins (on average) were found within Hong Kong waters in 2023, which is up somewhat from the last three years (i.e. 35 CWDs in 2022, 34 CWDs in 2021 and 32 CWDs in 2020). Seasonally, the CWD numbers within Hong Kong ranged from about 31-65 in 2023.

Land-based observations and theodolite tracking do not present overall estimates of numbers of dolphins. However, while the 2020, 2021, and 2022 data from LKC showed a reduction in CWD groups sighted and tracked compared to earlier years of 2017-2019, the 2023 data indicate a slight increase in numbers seen and tracked. It is possible that the data from the three years before 2020 represent a partial rebound of dolphin use of waters north of Lantau Island due to cessation of the intensive HZMB construction activities of 2013-2016 (see also Jefferson 2018). In 2022, continuing from 2020, and 2021, the ongoing 3RS Project marine construction activities reduced dolphin use in North Lantau waters in the way that was predicted in the 3RS EIA (Section 13.9.2). Although the major reclamation work for the 3RS project concluded in 2021 and some level of localized CWD rebound may be anticipated, a time delay in rebound could reasonably be expected. As stated above (Section 2.5.3.2), the apparent slight increase in 2023 should not be taken as unequivocally good news unless the trend continues. Theodolite tracking data will not be gathered in the next several years due to the low detection of CWD by such monitoring method, resulting in a lack of adequate survey data for conducting robust analysis, so the situation remains to be monitored by line transect and dolphin sound data, but without assessment of behavior or fine-scale movement patterns in this former hotspot of dolphin activity. Such arrangement has been agreed by the EPD and fits the requirements under the EM&A Manual.

It is important to remember that dolphins shift around within their habitat from year to year, due to both natural and anthropogenic factors. Thus, evidence of a decrease or increase in numbers from one year to the next should not necessarily be taken as indication of an overall population decline or recovery. Dolphins live for many decades and thus long-term monitoring using consistent methods is needed over an extended period of time in order to evaluate the true conservation status of the CWD population and how its use of Hong Kong waters is being affected.

The CWD construction phase monitoring data so far appear to be generally consistent with findings of the ecological assessments completed during the 3RS EIA, which predicted significant negative impacts during construction, including from the physical loss of habitat due to the reclamation (EIA Report Section 13.9.1). No unexpected ecological impacts on CWDs have been identified, while the increase in abundance in 2021-2023, though small, is encouraging nonetheless. However, it should be noted that dolphins shifting away from NL and nearby waters was anticipated during 3RS construction works, due to activities such as intensive seawall construction and marine filling activities, as had occurred in 2020 and early 2021, and this is broadly in line with EIA predictions.

In the 3RS EIA and as reported in the last several Annual EM&A Reports, it was predicted that dolphins would shift away from portions of their home range that are experiencing intense human activities and that appears to have been the case in 2020 as seawall works and marine filling activities intensified. These impacts are anthropogenic disturbances and therefore are of conservation concern; however, they are likely temporary and reversible and previous studies have supported that dolphin numbers can be expected to recover over the long-term, after completion of works (assuming that the habitat is properly protected and still of adequate quality – Jefferson 2018). EM&A monitoring for the 3RS will continue in 2024 as post-construction monitoring and then a further 12 months operation phase monitoring after the designation of NLMP, with the goal being to continue the examination of the trend of dolphin abundance after the completion of 3RS construction.

Monitoring of dolphins must continue in order to allow us to evaluate the full extent of impacts and any recovery that occurs in the future, and stabilization or an increase in abundance of Hong Kong CWDs is desirable for the long-term health of this population. As dolphin numbers in Hong Kong appeared to be going down in 2020, and remained much lower than in the past in 2021-2023, though with a slight increase compared with 2020, diligent monitoring will continue as post-construction monitoring and operation phase monitoring under the 3RS EM&A programme, and under Rebound Survey initiated by AA as an additional initiative for the monitoring of CWD. At this stage of 3RS construction, all recommended mitigations have been implemented and although impacts were occurred, these were temporary and within previously predicted patterns. As land formation is completed in the first quarter of 2023, and the proposed NLMP will come into effect on 1 November 2024, the situation should be improved. The effectiveness of the mitigation measures will be kept under review over the next few years, as post-construction phase CWD monitoring continues.

2.6.4.4 International Cetacean Expert’s Observation and Recommendations from the 3RS Project Long-term Monitoring Effort

In terms of the long-term conservation and management of the CWD population and specifically that portion that uses Hong Kong waters, it is important for numbers to stabilize now that marine construction has substantially completed, as the evidence suggests both that dolphins are using Hong Kong waters less intensively and that the overall population is declining (see Huang et al. 2012; Jefferson 2018; Jefferson et al. 2023). The intensive evaluation of construction methods that was undertaken in the EIA process for this project (which resulted in methods that are less harmful to dolphins, such the use of Deep Cement Mixing for site stabilization) should be seen as an example and should be emulated in future impact assessments. Importantly, there is also ongoing evaluation of the impacts, and the ability to re-evaluate, if any significant, unexpected impacts appear to be occurring. One issue of note for managers and enforcement personnel is that land-based tracking data identified 11 instances where HSF were going >15knots in the designated Vessel SCZ (Figure 20 of Appendix F) although monitoring the speed of HSF is not an objective of land-based theodolite tracking.

A major goal for Hong Kong (primarily the Agriculture, Fisheries and Conservation Department) and mainland management authorities should be to establish effective measures including, but not limited to, protection of critical foraging and breeding habitat, as well as important travel routes for the dolphins. Most importantly, the area along the entire west coast of Lantau Island has consistently been used as prime habitat by CWDs for the past several decades, but unfortunately numbers there have declined recently. This region has been confirmed by the current 3RS Project monitoring efforts to remain as the most important habitat for dolphins in Hong Kong, based on densities of CWD use. This has also been confirmed by the recent computer modeling study of dolphin habitat in Hong Kong (Jefferson et al. 2023), but most of the area still remains unprotected. The formation of Marine Parks/ Reserves for CWDs in this area should be seen as an extremely high priority for protecting critical dolphin habitat for the future of CWDs in Hong Kong. If it is used properly, the knowledge learned from the 3RS project, as well as the funding support and attention given the CWDs from this project (e.g., through the Marine Ecology Enhancement Fund), can be very helpful for management authorities in achieving the important long-term goal of stabilizing the CWD population, and ensuring its long-term health and survival.

2.6.5 Site Audit for CWD-related Mitigation Measures

During the reporting period, silt curtains were in place by the contractors for marine filling and dolphin observers were deployed by contractors in accordance with the Marine Mammal Watching Plan. Teams of at least two dolphin observers were deployed by contractors for continuous monitoring of the Dolphin Exclusion Zone (DEZ) for seawall construction and armour rock laying works in accordance with the DEZ Plan. Training for the dolphin observers on the implementation of MMWP and DEZ monitoring was provided by the ET prior to the aforementioned works, with the training records kept by the ET. From the contractors’ MMWP observation records, no dolphins or other marine mammals were observed within or around the silt curtains during the reporting period. As for DEZ monitoring records, no dolphins or other marine mammals were observed within the DEZs in this reporting period. These contractors’ records were audited by the ET during site inspection.

2.7 Sewage Flow Monitoring

2.8 Landscape and Visual Mitigation Measures

Implementation of applicable landscape and visual mitigation measures (reference to the environmental protection measures CM1 – CM10 in Appendix C) was monitored in accordance with the Manual and the Landscape & Visual Plan. All measures undertaken by both the contractor and the landscape contractor during the construction phase and first year of the operation phase are audited by a landscape architect, as a member of the ET, on a regular basis to ensure compliance with the intended aims of the measures.

Site inspection and audit are undertaken as necessary in the construction and operation phase in accordance with the Monitoring Programme for Landscape and Visual as shown in Table 2.20. In case of non-conformity, specific recommendations will be made, and actions will be proposed in accordance with the Event and Action Plan as shown in Table 2.21. No non-conformity was recorded during the reporting period.

Table 2.20: Monitoring Programme for Landscape and Visual

Stage	Monitoring Task	Monitoring Report	Form of Approval	Frequency
Detailed Design	Checking of design works against the recommendations of the landscape and visual impact assessments within the EIA shall be undertaken during detailed design and tender stage, to ensure that they fulfil the intention of the mitigation measures. Any changes to the design, including design changes on site shall also be checked.	Report by AAHK / PM confirming that the design conforms to requirements of EP.	Approved by Client	At the end of the Detailed Design Phase
Construction	Checking of the contractor’s operations during the construction period.	Report on Contractor's compliance, by ET	Counter signature of report by IEC	Weekly
Establishment Works	Checking of the planting works during the twelve-month Establishment Period after completion of each batch of transplanting works.	Report on Contractor's compliance, by ET	Counter signature of report by IEC	Every two months
Long Term Management (10 year)	Monitoring of the long-term management of the planting works in the period up to 10 years after completion of each batch of transplanting works.	Report on Compliance by ET or Maintenance Agency as appropriate	Counter signature of report by Management Agency	Annually

Table 2.21: Event and Action Plan for Landscape and Visual

Event Action Level	Action
	ET	IEC	AAHK / PM	Contractor
Design Check	Check final design conforms to the requirements of EP and prepare report.	Check report. Recommend remedial design if necessary.	Undertake remedial design if necessary.
Non-conformity on one occasion	Identify source. Inform IEC and AAHK / PM. Discuss remedial actions with IEC, AAHK / PM and Contractor. Monitor remedial actions until rectification has been completed.	Check report. Check Contractor’s working method. Discuss with ET and Contractor on possible remedial measures. Advise AAHK / PM on effectiveness of proposed remedial measures. Check implementation of remedial measures.	Notify Contractor. Ensure remedial measures are properly implemented.	Amend working methods to prevent recurrence of non-conformity. Rectify damage and undertake additional action necessary.
Repeated Non-conformity	Identify source. Inform IEC and AAHK / PM. Increase monitoring frequency. Discuss remedial actions with IEC, AAHK / PM and Contractor. Monitor remedial actions until rectification has been completed. If non-conformity stops, cease additional monitoring.	Check monitoring report. Check Contractor’s working method. Discuss with ET and Contractor on possible remedial measures. Advise AAHK / PM on effectiveness of proposed remedial measures. Supervise implementation of remedial measures.	Notify Contractor. Ensure remedial measures area properly implemented.	Amend working methods to prevent recurrence of non-conformity. Rectify damage and undertake additional action necessary.
Note: (1) For PM in Table 2.20, refers to Project Manager only.

2.8.1 The Implementation Status of the Environmental Protection Measures

The implementation status of the environmental protection measures is summarised below in Table 2.22. For trees which were managed by the Project during the reporting period, relevant measures have been implemented by Contracts 3302, 3508, and 3801.

Table 2.22: Implementation Status of the Environmental Protection Measures

Landscape and Visual Mitigation Measures during Construction Implementation Status	Implementation Status	Relevant Contract(s) in the Reporting Period
CM1- The construction area and contractor’s temporary works areas shall be minimised to avoid impacts on adjacent landscape.	The implementation of mitigation measures were checked by ET during weekly site inspection and clarified by the Contractors during the monthly Environmental Management Meetings. Implementation of the measures CM5, CM6 and CM7 by Contractors was observed.	All works contracts
CM2 – Reduction of construction period to practical minimum.
CM3 – Phasing of the construction stage to reduce visual impacts during the construction phase.
CM4 – Construction traffic (land and sea) including construction plants, construction vessels and barges shall be kept to a practical minimum.
CM5 – Erection of decorative mesh screens or construction hoardings around works areas in visually unobtrusive colours.
CM6 – Avoidance of excessive height and bulk of site buildings and structures
CM7 – Control of night-time lighting by hooding all lights and through minimisation of night working periods
CM8 – All existing trees shall be carefully protected during construction. Detailed Tree Protection Specification shall be provided in the Contract Specification. Under this specification, the Contractor shall be required to submit, for approval, a detailed working method statement for the protection of trees prior to undertaking any works adjacent to all retained trees, including trees in contractor’s works areas	Tree Protection Specifications have been provided in the relevant Contract Specifications respectively for implementation by the Contractors under the Project. The Contractors’ performance on the implementation of the trees maintenance and protection measures were observed and checked by the ET weekly during construction period.	3302, 3508, 3801
CM9 – Trees unavoidably affected by the works shall be transplanted where practical. A detailed Tree Transplanting Specification shall be provided in the Contract Specification, if applicable. Sufficient time for necessary tree root and crown preparation periods shall be allowed in the project programme	Tree Transplanting Specifications have been provided in the relevant Contract Specifications respectively for implementation by the Contractors under the Project where trees will unavoidably be affected by the construction works. The Contractors were required to submit Method Statements for tree transplanting prior to the transplanting works. Tree inspections were conducted by ET to check the tree transplanting works implemented by the Contractors on site. The Contractors’ performance on the implementation of trees maintenance and protection measures on transplanted trees were observed and checked by the ET bi-monthly during the 12-month establishment period after the completion of each batch of transplanting works. Long term management of the transplanted trees were currently monitored by ET annually.	3508
CM 10 – Land formation works shall be followed with advanced hydroseeding around taxiways and runways as soon as practical	The advanced hydroseeding works around taxiways and runways were partially completed at this stage and would resume in next phase.	To be implemented
OM7- Compensatory tree planting for all felled trees shall be provided to the satisfaction of relevant Government departments. Required numbers and locations of compensatory trees shall be determined and agreed separately with Government during the Tree Felling Application process under the relevant technical circulars.⁽¹⁾	The two batches of compensatory trees were planted and the bi-monthly site inspection for the 12-month establishment period was commenced. During the reporting period, the bi-monthly site inspection was undertaken in June, August, October and December 2023.	AAHK

Note:

(1) AAHK is the management and maintenance agency of the compensatory trees. Tree Felling Application is not required for 3RS project.

The 3RS Project is a mega project covering a number of detailed design contracts and many construction works contracts in different design and construction stages. Works areas would be taken up by different 3RS works contracts in stages with the commencement of construction, and the landscape and visual elements of these contract of the 3RS Project also designed and implemented at various stages of the Project.

Broad-brush tree survey and assessment were undertaken for the entire 3RS Project during EIA stage. After that, detailed design consultants had conducted more detailed tree surveys and assessments so that the landscape and visual elements were refined and aligned with their respective design areas. With the award of specific 3RS construction works contracts, the respective contractors would conduct their own detailed tree survey and assessment as necessary, to confirm the tree status at the time of their possession of the site. The tree survey and assessment from the respective contractors were taken as the baseline of that particular piece of works area before being affected by 3RS Project. Some of the tree group areas as identified in approved EIA report were affected by 3RS construction works as of 2023. Environmental monitoring and audit work which included the auditing of contractor’s work in landscape and visual aspects such as tree preservation, protection and transplantation was implemented in accordance with the updated construction programme, the relevant requirements of the EP, the Updated EM&A Manual and the Landscape & Visual Plan.

The total number of retained trees, transplanted trees and to-be-transplanted trees under the management of Project are summarized in Table 2.23. The tree schedule updated as of end 2023 is shown in Appendix H.

Table 2.23: Summary of the Number of Retained, Transplanted and To-be-transplanted Trees as of December 2023

Contract No.	Retained (nos.)	Transplanted (nos.)		To-be-transplanted (nos.)
Contract No.	Retained (nos.)	Establishment Period	Maintenance Period	To-be-transplanted (nos.)
3302⁽¹⁾	0	0	0	0
3503⁽²⁾	0	0	9	0
3508	34	0	12	0
3801⁽³⁾	3	0	5	0
Grand Total	37	0	26	0

Note:

(1) A work area of Contract 3302 including 9 retained trees was handed over to AAHK in September 2023.

(2) Contract 3503 was completed and the 9 transplanted trees, including T835, T836, T838, T812, T814, T815, T829, T830 and T831, were handed over to AAHK in February 2022.

(3) The 5 transplanted trees, including CT276, CT1253, CT1194, CT1794 and CT1795, were handed over to other management agencies. Details of the management agency are presented in Table 2.25.

Table 2.24 lists the affected tree ID together with the reasons for change of tree status between the tree schedules as of end 2022 and end 2023.

The total number of retained trees of the Project as of end 2023 was 37. Compared to 49 nos. of retained trees for existing works contracts reported in the tree schedule as of end 2022, the change in number was due to the following reasons:

● A tree under Contract 3508 was found fallen due to structural problem. (-1 no).

● Some trees under Contract 3302 were handed over to AAHK. (-9 nos).

● The trees under Contract 3508 were confirmed dead due to unrecoverable health problems. (-2 nos)

Table 2.24: Summary of the Tree Status Changes between end 2022 and end 2023

Tree ID(s)	Contract	Status as of end 2022	Status as of end 2023	Remarks	Impacts to Total Tree Number
T1381A	3508	Retain	Fell	1 no. of tree was found fallen due to structural problem.	Retain: - 1 no.
T01, T03, T04, T07, T08, T09, T10, T11, T12	3302	Retain	Retain	9 nos. of trees were handed over to AAHK.	Retain: - 9 nos.
T1382A, T1391A	3508	Retain	Fell	2 nos. of trees were confirmed dead and then removed due to unrecoverable health condition.	Retain: - 2 nos.

In this reporting period, the cumulative total number of transplanted trees under the Project remained unchanged (i.e., 26) comparing to the previous reporting period. The details of transplanted trees are summarised in Table 2.25. Photos of the transplanted trees are presented in Table 2.26.

During the reporting period, the compensatory trees bi-monthly site inspections for 12-month establishment period were undertaken in June, August, October and December 2023.

Table 2.25: Details of the Transplanted Trees

Tree ID	Transplant Date	Management Stage	Management Agency	Remarks
CT276	3 May 2018	Long Term Management period Jun 2019 – May 2028	Southern Landside Petrol Filling Station	Establishment Period was completed. Next inspection will be conducted in February 2024.
CT1253	4 May 2018	Long Term Management period Jun 2019 – May 2028	Southern Landside Petrol Filling Station
T835	22 Jan 2020	Long Term Management period Feb 2021 – Jan 2030	AAHK	Establishment Period was completed. Next inspection will be conducted in February 2024.
T836	13 Dec 2019	Long Term Management period Feb 2021 – Jan 2030	AAHK
T838	22 Jan 2020	Long Term Management period Feb 2021 – Jan 2030	AAHK
T812	21 Dec 2020	Long Term Management period Jan 2022 – Dec 2031	AAHK	Establishment Period was completed. Next inspection will be conducted in December 2024.
T814	20 Dec 2020	Long Term Management period Jan 2022 – Dec 2031	AAHK
T815	15 Dec 2020	Long Term Management period Jan 2022 – Dec 2031	AAHK
T829	18 Dec 2020	Long Term Management period Jan 2022 – Dec 2031	AAHK
T830	14 Dec 2020	Long Term Management period Jan 2022 – Dec 2031	AAHK
T831	19 Dec 2020	Long Term Management period Jan 2022 – Dec 2031	AAHK
T1493	6 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508	Establishment Period was completed. Next inspection will be conducted in July 2024.
T1494	6 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1495	10 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1496	5 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1497	5 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1498	29 Jun 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1499	29 Jun 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1500	30 Jun 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1501	30 Jun 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1502	5 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1503	6 Jul 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
T1504	24 Jun 2021	Long Term Management period Aug 2022 – Jul 2031	Contract 3508
CT1194	4 May 2018	Long Term Management period Jun 2019 – May 2028	Southern Landside Petrol Filling Station	Establishment Period was completed. Uprooted and collapsed due to Typhoon Higos on 18 August 2020. Tree removal was conducted as recommended by tree specialist of the contractor of Southern Landside Petrol Filing Station.
CT1794	3 May 2018	Long Term Management period Jun 2019 – May 2028	AsiaWorld-Expo	Establishment Period was completed. The tree within the land parcel was acquired by the government for construction of emergency hospital to handle COVID19 pandemic at AsiaWorld-Expo. The tree was felled in late 2020.
CT1795	3 May 2018	Long Term Management period Jun 2019 – May 2028	AsiaWorld-Expo	Establishment Period was completed. The tree within the land parcel was acquired by the government for construction of emergency hospital to handle COVID19 pandemic at AsiaWorld-Expo. The tree was felled in late 2020.

Table 2.26: Photos of the Existing Transplanted Trees in the Reporting Period

Under 10-year Long-term Management (Jun 2019 – May 2028):

CT276	CT1253
Under 10-year Long-term Management (Feb 2021 – Jan 2030):

T835	T836	T838

Under 10-year Long-term Management (Jan 2022 – Dec 2031):

T812	T814	T815

T829	T830	T831

Under 10-year Long-term Management (Aug 2022 – Jul 2031):

T1493	T1494	T1495

T1496	T1497	T1498

T1499	T1500	T1501

T1502	T1503	T1504

2.9 Environmental Site Inspection

Site inspections of the construction works were carried out on a weekly basis to monitor the implementation of proper environmental pollution control and mitigation measures for the Project. Bi-weekly site inspections were also conducted by the IEC. Besides, ad-hoc site inspections were conducted by ET and IEC if environmental problems were identified, or subsequent to receipt of an environmental complaint, or as part of the investigation work. During the reporting period, ET conducted 900 sessions of site inspection and 79 sessions of ah-hoc site inspections. These site inspections provided a direct means to reinforce the specified environmental protection requirements and pollution control measures in construction sites.

During site inspections, environmental situation, status of implementation of pollution control and mitigation measures were observed both within the site area as well as outside the project sites which was likely to be affected, directly or indirectly, by the site activities. Environmental documents and site records, including waste disposal record, maintenance record of environmental equipment, and relevant environmental permit and licences, were also checked on site. Observations were recorded in the site inspection checklist and passed to the contractor together with the appropriate recommended mitigation measures where necessary in order to advise contractors on environmental improvement, awareness and on-site enhancement measures. The observations were made with reference to the following information during the site inspections:

● The EIA and EM&A requirements;

● Relevant environmental protection laws, guidelines, and practice notes;

● The EP conditions and other submissions under the EP;

● Monitoring results of EM&A programme;

● Works progress and programme;

● Proposal of individual works;

● Contract specifications on environmental protection; and

● Previous site inspection results.

Good site practices were observed in site inspections during the reporting period. Advice was given when necessary to ensure the construction workforce were familiar with relevant procedures, and to maintain good environmental performance on site. Regular toolbox talks on environmental issues were organized for the construction workforce by the contractors to ensure understanding and proper implementation of environmental protection and pollution control mitigation measures. Environmental briefings on EP and EM&A requirements were also provided to the new contracts by ET.

Summary of implementation status of the environmental mitigation measures for the construction phase of the Project during the reporting period is provided in Appendix C.

2.10 Audit of the SkyPier High Speed Ferries

The Marine Travel Routes and Management Plan for High Speed Ferries of SkyPier (the SkyPier Plan) was submitted to the Advisory Council on the Environment (ACE) for comment and subsequently submitted to and approved by EPD in November 2015 under EP Condition 2.10. The approved SkyPier Plan is available on the dedicated website of the Project. In the SkyPier Plan, AAHK has committed to implementing the mitigation measure of requiring HSFs of SkyPier travelling between HKIA and Zhuhai / Macau to start diverting the route with associated speed control across the area, i.e. SCZ, with high CWD abundance. The route diversion and speed restriction at the SCZ have been implemented since 28 December 2015. The IEC has also performed audit on the compliance of the requirements as part of the EM&A programme. The latest summary of key audit findings in the reporting period is presented in Table 2.27.

According to the approved SkyPier Plan, dolphin habitat index has been reviewed in the reporting period based on findings of the AFCD’s marine mammals monitoring report 2022-23 and historical dolphin density records. Grids for dolphin hotspot remained largely unchanged, thus the HSF route diversion arrangement remained unchanged.

Due to the operational needs, the SkyPier HSF services to/from Zhuhai has been suspended. In total, 285 ferry movements HKIA SkyPier and Macau were audited in the reporting period. The daily movements of all SkyPier HSFs in the reporting period, including those not using the diverted route, ranged between 5 and 54, which falls within the maximum daily cap number of 125. The annual daily average of all SkyPier HSF movements in the reporting period was 37, which falls within the annual daily average cap of 99 SkyPier HSF movements.

The 285 ferry movements audited were all travelled through the SCZ with average speeds at or below 15 knots, which complied with the SkyPier Plan. Two deviation cases were recorded during the reporting period. One deviation case regarding the ferry movement not entered/ left the SCZ through the gate access points was recorded in May 2023. The case was due to strong tidal wave and current. The other deviation case was recorded in July 2023. It was related to a ferry movement with deviation from the diverted route. An investigation was carried out and it was found that the deviation was due to safety reason to avoid hitting a number of floating objects.

Insufficient AIS data were received from some HSFs during the reporting period. After investigation, it was found that the data missing due to (1) signal interference; and (2) AIS equipment malfunction. Ferry operators were requested to provide the radar track photo / video which indicated the vessel entered the SCZ through the gate access points and there was no speeding in the SCZ. Ferry operators’ explanations were accepted. The ferry operators were reminded to maintain good condition of the AIS transponders.

Table 2.27: Summary of Key Audit Findings against the SkyPier Plan

Key Audit Findings	Jan-23	Feb-23	Mar-23	Apr-23	May-23	Jun-23	Jul -23	Aug-23	Sep-23	Oct -23	Nov-23	Dec-23
Total number of HSF movements recorded and audited for HSF to/from Macau	17	16	24	24	28	26	24	26	24	26	26	24
Use diverted route and enter / leave SCZ through Gate Access Points	17	15	24	24	27	26	24	26	24	26	26	24
No. of SkyPier HSFs in compliance with average speed within 15 knots in SCZ	17	16	24	24	28	26	24	26	24	26	26	24
Range of daily movement (capped daily average of 99 for all SkyPier HSFs)	5-24	22-25	23-29	26-36	35-38	37-40	33-48	16-50	42-54	6-52	49-52	44-54

Source: Excerpted from Monthly and Quarterly EM&A Reports

2.11 Audit of the Construction and Associated Vessels

The audit of construction and associated vessels in accordance with the Marine Travel Route and Management Plan for Construction and Associated Vessel (MTRMP-CAV) has started since August 2016. ET has audited relevant information including AIS data, vessel tracks and other relevant records provided by the contractors to ensure that the contractors were fully complied with the requirements of the MTRMP-CAV. The Maritime Surveillance System (MSS) was launched in March 2017. The MSS automatically recorded deviation cases such as speeding, entering no entry zone, and not travelling through designated gates. ET conducted checking to ensure the MSS records all deviation cases accurately. The 3-month rolling programme submitted by contractors for construction vessel activities were also checked every month to ensure the logistic of construction vessels were well planned to achieve a practicable minimum. The IEC has also performed audit on the compliance of the requirements as part of the EM&A programme.

A total of 2 skipper training workshops were held by ET during the reporting period with 3 captains of construction vessels associated with the 3RS contracts to familiarise them with the predefined routes, general education on local cetaceans, guidelines for avoiding adverse water quality impact, the required environmental practices / measures while operating construction and associated vessels under the Project, and guidelines for operating vessels safely in the presence of CWDs. Another 11 skipper training workshops were held with 15 captains by contractors’ Environmental Officers and competency tests were conducted subsequently with the trained captains by ET. In addition, ET participated Marine Management Liaison Group meetings to assist and resolve any marine issues which might be encountered under the Project.

2.12 External Stakeholder Engagement

In accordance with the EP’s requirements of setting up Community and Professional Liaison Groups, the AAHK has been continuing to proactively reach out to a wide spectrum of external stakeholders to update them on the environmental aspects of the Project and to seek their insights and views. There were continuous exchanges with the local communities, relevant professionals, experts, and other stakeholders. Below are highlights of the engagement activities held in 2023.

2.12.1 Community Liaison Groups

In order to enhance transparency and communication with the community in a proactive way, five Community Liaison Groups (CLGs) were set up in 2012 in the neighbouring districts of HKIA, namely Islands, Kwai Tsing, Shatin, Tsuen Wan and Tuen Mun. The CLGs are comprehensive platforms for the AAHK to update the community leaders about the detailed design, progress of construction and operation, and environmental monitoring and audit results of the Project, and listen to their views on various topics related to HKIA and the Project, including environmental matters. The AAHK also leverages on the CLGs to exchange views with the community on the latest airport developments, hence enhancing airport services and helping to contribute to the betterment of these districts. The CLGs have a total of about 130 members involving district councillors and community leaders. In 2023, two meetings cum airport visits were held in February and August respectively. Project information including the latest development of the 3RS Project, environmental monitoring and audit results, and details on the implementation of environmental and ecological enhancement measures were presented in the meeting.

2.12.2 Professional Liaison Group and Green Non-Governmental Organizations

The Professional Liaison Group, comprising 19 members of relevant professionals and experts, was set up to enhance transparency and communication, as well as enquiries and complaints-handling on all environmental issues related to the Project; and to promote community cooperation and participation and implementation of suitable local environmental enhancement works that are included in the Environmental Permit. In 2023, two meetings cum airport visits were held in April and November respectively. Project information including the latest development of the 3RS Project, environmental monitoring and audit results, and details on the implementation of environmental and ecological enhancement measures were presented in the meeting.

Roundtable meetings with Green Non-Governmental Organizations (NGOs) were proactively arranged to facilitate exchanges on environmental issues related to the Project. Updates of the Project, including environmental monitoring and audit results and details on the implementation of environmental and ecological enhancement measures were shared with the participants. In 2023, two meetings cum airport visits were held in April and November respectively.

2.12.3 Fishermen Liaison

In an effort to deepen outreach to the fishermen community, a dedicated Fishermen Liaison Group was set up in November 2016 to share updates on environmental matters and progress of construction and operation with the chairmen and leaders of fishermen groups and associations. In 2023, one meeting cum airport visit was held in June.

2.12.4 Other Stakeholders

The AAHK attended a Legislative Council Panel on Economic Development meeting in July 2023 to share with members updates on the development of the 3RS Project and submitted another update paper in December 2023. Furthermore, the AAHK submitted a paper to the Advisory Council on the Environment (ACE) in July 2023 reporting an update on the implementation of the environmental mitigation and enhancement measures in association with the 3RS Project.

To encourage two-way communications with stakeholders and the community, a dedicated telephone hotline and email has been set up since December 2015. No enquiry was received via the telephone hotline and sixteen enquiries were received via the dedicated email in 2023.

2.13 Review of the Key Assumptions Adopted in the EIA Report

With reference to Appendix E of the Manual, it is noted that the key assumptions adopted in approved EIA report for the construction phase are still valid and no major changes are involved. The environmental mitigation measures recommended in the approved EIA Report remain applicable and shall be implemented in undertaking construction works for the Project.

2.14 Key Environmental Issues for the Coming Reporting Period

The key environmental issues for the Project in the coming reporting period are expected to be associated with construction activities including:

· Generation of dust from construction works and stockpiles;

· Noise from operating equipment and machinery on-site;

· Generation of site surface runoffs and wastewater from activities on-site;

· Sorting, recycling, storage and disposal of general refuse and construction waste;

· Reuse of treated marine sediments from piling and excavation works; and

· Management of chemicals and avoidance of oil spillage on-site.

The implementation of required mitigation measures by the contractors will be monitored by the ET.

3 Report on Non-compliance, Complaints, Notifications of Summons and Prosecutions

3.1 Compliance with Other Statutory Environmental Requirements

During the reporting period, environmental related licenses and permits required for the construction activities were checked. No non-compliance with environmental statutory requirements was recorded.

3.2 Analysis and Interpretation of Complaints, Notification of Summons and Status of Prosecutions

3.2.1 Complaints

Twelve environmental complaints were received in the reporting period. Ten environmental complaints were related to air quality and one environmental complaint was related to noise and one environmental complaint was related to air quality and noise. The environmental complaints were attended and investigations were conducted by the ET in accordance with the Manual and the Complaint Management Plan. The summary of the complaints and analysis is presented in Appendix G.

3.2.2 Notifications of Summons or Status of Prosecution

No notification of summons or prosecution was received in the reporting period.

3.3 Cumulative Statistics

Cumulative statistics on exceedance, non-compliance, complaints, notifications of summons and status of prosecutions are summarized in Appendix G.

4 Conclusion and Recommendation

In the reporting period from 1 January 2023 to 31 December 2023, the EM&A programme has been implemented in accordance with the Manual of the Project. The EM&A works carried out during the reporting period include construction dust and noise measurements, general impact water quality monitoring, post-construction phase water quality monitoring, vessel line-transect surveys, land-based theodolite tracking surveys supplemented with passive acoustic monitoring for CWD monitoring, waste monitoring, as well as environmental site inspections and landscape and visual monitoring for the Project’s construction works.

The monitoring results in relation to the construction dust, construction noise, construction waste and CWD did not trigger their corresponding Action or Limit Levels during the reporting period. No non-conformity was recorded for landscape and visual monitoring in the reporting period.

For general impact water quality monitoring, the monitoring results for turbidity obtained during the reporting period complied with the corresponding Action and Limit Levels stipulated in the EM&A programme. For DO and SS, some of the monitoring results triggered the relevant Action or Limit Levels during the reporting period. Relevant investigation and follow-up procedures were conducted according to the EM&A programme. The investigation findings concluded that the cases were not related to the Project. To conclude, the construction activities in the reporting period did not introduce adverse impact to all water quality sensitive receivers.

With the completion of land formation works in the first quarter of 2023, termination of the construction phase water quality impact monitoring was proposed to EPD with approval granted on 30 October 2023 and the general impact water quality monitoring was terminated after 31 October 2023. Post-construction phase water quality monitoring exercise was carried from 14 November 2023 to 9 December 2023. The overall post-construction phase water quality monitoring result did not reveal significant changes of the water quality when comparing with baseline water quality monitoring. Besides, during general impact water quality monitoring, while outliers were observed, investigations had been carried out according to the relevant requirements of the Updated EM&A Manual whenever such outliners triggered the Action or Limit Levels, and the investigation findings concluded that these outliers were not due to the Project but could be attributed to natural fluctuation/ seasonal variations/ external factors in the vicinity. Details of the investigation findings have been documented in the relevant Construction Phase Monthly EM&A Reports. Therefore, it can be concluded that the marine works of the Project during construction phase did not cause deterioration in or adverse impacts on the marine water quality surrounding the Project site.

A total of around 5384.9 km survey effort was conducted for the vessel line-transect monitoring for CWDs during the 12-month monitoring period. A total of 160 groups of 542 CWDs were sighted in NWL, AW, WL and SWL survey areas. No CWDs were recorded in the NEL survey area. The combined encounter rates by number of dolphin sightings and by number of dolphins were 3.06 and 10.35 respectively. No triggering of Action and Limit Levels for encounter rates were recorded during the construction phase during 2023. Overall abundance of CWD in Hong Kong western waters was estimated at 40 dolphins in 2023 from line-transect analysis. CWD occurrence from land-based surveys around Lung Kwu Chau was only recorded during winter and summer seasons. Waters off Lung Kwu Chau continue to be habitat used primarily for travelling and foraging. Passive acoustic monitoring provides evidence that dolphins continued using the area around south of Sha Chau in 2023, especially in winter, and then primarily at night.

The construction phase CWD monitoring was continued until the end of December 2023 so as to collect a full-year set of monitoring data to facilitate evaluation of CWD abundance on an annual basis. A post-construction phase CWD monitoring includes vessels line-transect survey would be carried out for 12 months, starting from January 2024.

The treatment and backfilling works for all marine sediment excavated from the areas without ground improvement works by Deep Cement Mixing were deemed to be completed in 2022. On the other hand, excavation, treatment and backfilling works for marine sediment excavated from reclaimed land areas with ground improvement works by Deep Cement Mixing were still undergoing during the reported period.

Site inspections and audits were undertaken in accordance with the monitoring programme for landscape and visual impacts during construction and establishment works phases. No non-conformity was recorded during the reporting period.

In total, 285 HSF movement between HKIA SkyPier and Macau was recorded in the reporting period. The daily movements of all SkyPier HSFs in the reporting period, including those not using the diverted route, ranged between 5 and 54, which falls within the maximum daily cap number of 125. The annual daily average of all SkyPier HSF movements in the reporting period was 37, which falls within the annual daily average cap of 99 SkyPier HSF movements.

The audit of construction and associated vessels has started since August 2016. ET has conducted audit to ensure that the contractors were fully complied with the requirements of the MTRMP-CAV. The MSS was launched in March 2017. The MSS automatically recorded the deviation case such as speeding, entering no entry zone, not travelling through the designated gate. ET conducted checking to ensure the MSS records all deviation cases accurately. A total of 2 skipper training workshops were conducted by the ET during the reporting period with captains of construction vessels associated with 3RS contracts. Another 11 skipper training workshops were held by contractors’ Environmental Officers and competency tests were conducted subsequently with the trained captains by ET.

On the implementation of MMWP, silt curtains were in place by the contractors for marine filling and dolphin observers were deployed in accordance with the MMWP. On the implementation of DEZ Plan, dolphin observers were deployed by the contractors for continuous monitoring of the DEZ for seawall construction and armour rock laying works in accordance with the DEZ Plan. Trainings for the dolphin observers on the implementation of MMWP and DEZ monitoring were provided by the ET prior to the aforementioned works. From the contractors’ MMWP observation records, no dolphins or other marine mammals were observed within or around the silt curtains during the reporting period. As for DEZ monitoring records, no dolphins or other marine mammals were observed within the DEZs in this reporting period.

AAHK strives to be highly transparent in its works and continues to engage with stakeholders through meetings and communications. Having said that, the dedicated 3RS Project website provides up-to-date information including EM&A results, updated plans and submissions in accordance with requirements in the EP, materials of the liaison group meetings, flyers introducing the environmental initiatives of the 3RS Project, as well as information on the status and operation of the Marine Ecology Enhancement Fund and the Fisheries Enhancement Fund.

Overall, the recommended environmental mitigation measures, as included in the EM&A programme, have been effectively implemented during the reporting period. Also, the EM&A programme implemented by the ET has effectively monitored the construction activities and ensured the proper implementation of mitigation measures.

[1] The Manual is available on the Project’s dedicated website (accessible at: http://env.threerunwaysystem.com/en/index.html).