Figure 1.1a	Locations of Key Construction Activities (before commissioning of 3RS)
Figure 1.1b	Locations of Key Construction Activities (after commissioning of 3RS)
Figure 2.1	Locations of Air and Noise Monitoring Stations and Chek Lap Kok Wind Station
Figure 2.2	Overall Sampling Grids for the Newly Reclaimed Area
Figure 2.3	The Backfilling Locations for Treated Marine Sediment
Figure 2.4	Vessel based Dolphin Monitoring Transects in Construction, Post-Construction and Operation Phases

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	Chinese White Dolphin Monitoring Results
Appendix F	Summary of Environmental Complaints and Cumulative Statistics on Exceedances, Notification of Summons, and Prosecution
Appendix G	Tree Schedule

Abbreviations

3RS	Three-Runway System
AAHK	Airport Authority Hong Kong
AECOM	AECOM Asia Company Limited
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
CAP	Contamination Assessment Plan
CAR	Contamination Assessment Report
CDS	Conventional Distance Sampling
CLGs	Community Liaison Groups
COVID	Coronavirus Disease
CWD	Chinese White Dolphin
CV	Coefficient of Variation
DCM	Deep Cement Mixing
DEZ	Dolphin Exclusion Zone
DPSE	Number of Dolphins per 100 Units of Survey Effort
EIA	Environmental Impact Assessment
EM&A	Environmental Monitoring & Audit
EP	Environmental Permit
EPD	Environmental Protection Department
EVT	Eastern Vehicular Tunnel
ET	Environmental Team
HDD	Horizontal Directional Drilling
HKIA	Hong Kong International Airport
HOKLAS	The Hong Kong Laboratory Accreditation Scheme
HSF	High Speed Ferry
HZMB	Hong-Kong-Zhuhai-Macao Bridge
IEC	Independent Environmental Checker
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
NLMP	North Lantau Marine Park
NWL	Northwest Lantau
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
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
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 9^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 2024 to 31 December 2024.

The new North Runway was commissioned in November 2022. Following the completion of reconfiguration works on the Centre Runway, the Three-Runway System (3RS) was commissioned on 28 November 2024. Meanwhile, expansion of the Terminal 2 (T2), construction of the T2 Concourse (T2C), installation of a new automated people mover system and baggage handling system, as well as construction of airport support infrastructure, utilities and facilities are ongoing.

The North Lantau Marine Park (NLMP) was designated on 1 November 2024. The NLMP connects with the adjacent Sha Chau and Lung Kwu Chau Marine Park (SCLKCMP), and the Brothers Marine Park (BMP). Together, these three parks form a contiguous networks of marine protected areas covering approximately 4,570 hectares. This interconnected system enhances the protection of important habitats, particular for the Chinese White Dolphin.

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

● Temporary platform construction;

● Marine sediment treatment works; and

● Filling materials delivery & backfilling.

Airfield Works:

Contract 3302 Eastern Vehicular Tunnel Advance Works

● Defects rectification works at Eastern Vehicular Tunnel; and

● Stormwater drainage diversion and underground utilities works.

Contract 3305 Airfield Ground Lighting System

● Enhanced vehicular warning light hardware installation;

● Cable containment & power supply system installation; and

● Cable laying works.

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

● Equipment installation; and

● Structured cabling.

Contract 3308 Foreign Object Debris Detection System

● Construction of foundation; and

● Tower modification works.

Contract 3310 North Runway Modification Works

● Architectural, builder’s work and finishing works;

● Ground improvement works (transition layer and backfilling);

● Pavement works for runway;

● Construction of stormwater drainage and underground utilities works;

● Construction of vehicular tunnel;

● Construction of box culvert;

● Aviation fuel pipe works;

● Landscape works; and

● Reinforced concreting works and filling works.

Terminal 2 Concourse and Apron Works:

Contract 3402 New Integrated Airport Centres Enabling Works

● Road resurfacing works.

Contract 3403 New Integrated Airport Centres Building and Civil Works

● Electrical and mechanical works;

● Testing and commissioning works;

● Backfilling works; and

● Defects rectification works.

Contract 3404 Integrated Airport Control System

● System equipment installation works;

● Cable laying works;

● Electrical and mechanical works; and

● System testing and maintenance.

Contract 3405 Third Runway Concourse Foundation and Substructure Works

● Structure works;

● Tunnel concreting & backfilling works; and

● Drainage works.

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, trial run and operation of concrete batching plant;

● Marine sediment treatment works; and

● Pavement works.

Terminal 2 Expansion:

Contract 3508 Terminal 2 Expansion Works

● Pier, deck and parapet construction;

● Site formation and cofferdam works;

● Drainage construction and utilities works;

● Roof works, construction of beams and columns;

● Link bridge works and crossroad duct laying works;

● Electrical and mechanical works;

● Backfilling works;

● Pump station and electrical station construction 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; and

● Cable containment and cable laying works.

Contract 3602 Existing APM System Modification Works

● Concrete plinth and track plinth construction;

● Guide props installation works;

● Restoration of buffer stop and stinger;

● Platform screen door installation works;

● New Swing Gates installation works; and

● Cabling works.

Contract 3603 3RS Baggage Handling System (BHS)

● BHS, conveyor, fire service and lighting system installation;

● Electrical and mechanical component installation; and

● Steel work installation.

Airport Support Infrastructure:

Contract 3801 APM and BHS Tunnels on Existing Airport Island

● Backfilling works;

● Drainage and underground utilities works;

● Demolition works;

● Hydroseeding works; and

● Road reinstatement works.

Contract 3802 APM and BHS Tunnels and Related Works

● Excavation and lateral supports;

● APM and BHS Tunnel, box culvert construction and superstructure works;

● Reinforced concrete works;

● Backfilling works;

● Architectural, builder's work and finishing works; and

● Marine sediment treatment works.

Contract 3804 East and Landside Fire Stations

● Site setup and formation works;

● Bored pile works;

● Superstructure works and architectural, builder’s work and finishing works;

● Piles interface core and pile cap construction works;

● Electrical and mechanical works;

● Backfilling works; and

● Underground Utilities Works.

Contract 3805 New Airport District Police Operational Base

● Site formation works;

● Bored pile works;

● Pile cap works;

● Construction of drainage system and manhole construction work; and

● Marine sediment treatment works.

Construction Support:

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 3733 Emergency Repair Service

● Marine sediment treatment works.

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, cable laying and duct installation;

● Cold milling and resurfacing; and

● Backfilling.

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	384
Noise Monitoring	210
Vessel line-transect Surveys for Chinese White Dolphin (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 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.

In accordance with Section 6.2.1.2 of the Manual, the routine monitoring of hydrogen sulphide (H₂S) levels for the sewerage system of 3RS commenced after the commissioning of the 3RS on 28 November 2024.

Summary Findings of the EM&A Programme

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

Monitoring results of construction dust, construction noise and construction waste 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.

Following the commissioning of 3RS in November 2024, the importation of public fill materials from the Government’s Public Fill Banks is no longer required for backfilling works. However, the C&D materials generated on-site continue to be reused. In 2024, the total volume of public fill imported was 997,831.5 m³. As of the end of 2024, the accumulative amount of public fill used for the Project reached 13,491,212.34 m³.

The post-construction phase CWD monitoring commenced in January 2024 and was completed in December 2024, as required in the EM&A Manual Section 10.2.3.2. This monitoring arrangement was agreed upon by Agriculture, Fisheries and Conservation Department (AFCD) and EPD in December 2023. A total of around 5391.2km survey effort was conducted for the vessel line-transect monitoring for CWDs during the 12-month post construction phase monitoring period. A total of 151 groups comprising 490 individual CWDs were sighted in NWL, AW, WL and SWL survey areas. No CWDs were recorded in the NEL survey area. Based on the line-transect analysis, the overall abundance of CWD in Hong Kong western waters was estimated at 60 dolphins in 2024.

A 12-month operation phase CWD monitoring by vessels line-transect survey would be commenced in January 2025.

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 recorded.	Nil.
Complaints Received	√		Ten complaints were received in 2024: 22 Jan, 15 Mar (2 complaints), 21 May, 23 May (2 complaints), 3 Sep, 4 Oct, 25 Oct and 31 Oct 2024.	The complaint investigations were carried out in accordance with the Complaint Management Plan. Details are presented in Section 3.2.1.
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.

1 Introductions

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 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 9^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 2024 to 31 December 2024.

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 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)	Senior HSE Manager	Qian Zhang	5377 7976
	Environmental Officer	Ivan Mak	9422 4805

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	Carrie Kwan	9276 0551

Party

Position

Name

Telephone

Contract 3508 Terminal 2

Expansion Works

(Gammon Engineering &

Construction Company

Limited)

Project Manager

Richard Ellis

6201 5637

Environmental Officer

Carrie Kwan

9276 0551

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
	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	Zhang Jinyuan	6708 0506
	Environmental Representative	Karis Lam	6084 9745
Contract 3805 New Airport District Police Operational Base (Chinney Construction Co., Ltd.)	Project Manager	Peter Li	9628 0768
	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.)	Senior Project Manager	Thomas Lui	9011 5340
	Environmental Officer	John Mak	6273 8703
Contract 3722Western 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)	General Manager	Gabriel Chan	2435 3260
	Environmental Officer	Rex Wong	2695 6319
Contract 3908 Quay Management Services (Gitanes – Crown Asia Joint Venture)	Project Manager	Ian Li	9750 6438
	Environmental Officer	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
Senior Project Engineer	Sunny Lau	6203 5686

Party

Position

Name

Telephone

132kV Cable

(CLP Power Hong Kong Limited / Kum Shing (K.F.) Construction Company Limited)

Engineer

Ken Fung

6391 9087

Senior Project Engineer

Sunny Lau

6203 5686

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 reconfiguration works were completed, the flight check and aircraft crash and rescue exercise were completed on the Centre Runway in September and October 2024, respectively. Thereafter, the 3RS was commissioned on 28 November 2024.

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 rock armour laying works, filling and ground improvement works, pavement works, Terminal 2 concourse superstructure works, tunnel works for Automated People Mover (APM) and Baggage Handling System (BHS) and works on existing airport island involved mainly centre runway modification works, Terminal 2 expansion works, modification and tunnel works for APM and BHS, and preparation works for utilities, with activities including road and drainage works, demolition, piling, excavation works and 132kV cable laying works.

The locations of the key construction activities before and after commissioning of 3RS are presented in Figure 1.1a and Figure 1.1b.

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 for the annual sewage flow monitoring was approved by EPD. The annual flow monitoring commenced from June 2021 and was concluded 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 details were approved by EPD and the monitoring commenced after the commissioning of the 3RS on 28 November 2024.
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 CWD monitoring was completed in December 2024.
Operation Phase Monitoring	12 months of operation phase CWD monitoring upon full implementation of North Lantau Marine Park. Vessel line transect survey: Two full surveys per month.	Operation phase CWD monitoring would be commenced from January 2025.
Operation Phase Audit	SkyPier High Speed Ferries (HSF) implementation measures: Once every three months for a period of one year upon operation of 3RS. Spill Response Plan implementation measures: Once every six months for a period of one year upon operation of 3RS.	The 1^st audit would be conducted in February 2025. The 1^st audit would be conducted in May 2025.
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	No Marine Mammal Watching Plan (MMWP) implementation measures was conducted during the reporting period.
Dolphin Exclusion Zone (DEZ) Plan implementation measures	Monitor and check	No Dolphin Exclusion Zone (DEZ) monitoring was conducted after Jan 2024.
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

Considering the nature of construction activities during the reporting period, impact monitoring was undertaken for air quality, noise, waste management, landscape and visual. In addition, post-construction phase CWD monitoring was also carried out.

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 trainings, and regular environmental management meetings were conducted during the reporting period which are summarized as below:

● 4 skipper trainings provided by ET; and

● 201 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 2024	100%	100%
Feb 2024	100%	100%
Mar 2024	100%	100%
Apr 2024	100%	100%
May 2024	100%	100%
Jun 2024	100%	100%
Jul 2024	100%	100%
Aug 2024	100%	100%
Sep 2024	100%	100%
Oct 2024	100%	100%
Nov 2024	100%	100%
Dec 2024	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 2024	Sunny to Cloudy	Northwest to East
Apr – Jun 2024	Sunny to Drizzle	Northwest to Southeast
Jul – Sep 2024	Sunny to Cloudy	Southwest to North
Oct – Dec 2024	Sunny to Cloudy	Northwest to Southeast

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, L_eq_(30mins)dB(A)
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)
Notes: (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). (ii) As described in Section 4.3.3 of the Manual, noise monitoring NM2 will only commence after occupation of the future Tung Chung Development. (iii) According to Section 4.3.3 of the Manual, the noise monitoring NM3A was temporarily suspended starting from 1 September 2018 and would be resumed with the completion of the Tung Chung East Development.

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 2024	100%	100%	100%	100%
Feb 2024	100%	100%	100%	100%
Mar 2024	100%	100%	100%	100%
Apr 2024	100%	100%	100%	100%
May 2024	100%	100%	100%	100%
Jun 2024	100%	100%	100%	100%
Jul 2024	100%	100%	100%	100%
Aug 2024	100%	100%	100%	100%
Sep 2024	100%	100%	100%	100%
Oct 2024	100%	100%	100%	100%
Nov 2024	100%	100%	100%	100%
Dec 2024	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 2024	Sunny to Cloudy
Apr – Jun 2024	Sunny to Drizzle
Jul – Sep 2024	Sunny to Cloudy
Oct – Dec 2024	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

The construction phase water quality impact monitoring was carried out according to Section 5.1.8 of the Updated EM&A Manual. With the completion of land formation works including seawall construction and all marine filling 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. The water quality impact monitoring was terminated after 31 October 2023.

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 impact monitoring stations, sensitive receivers stations and control stations during construction phase, from 14 November 2023 to 9 December 2023. The comparison between the baseline, construction phase and post-construction phase monitoring results were presented in the Annual EM&A report No.8. The post-construction phase water quality monitoring did not reveal any significant changes in water quality compared to the baseline monitoring, It can therefore be concluded that the marine works carried out during construction phase did not cause deterioration or adverse impacts on the marine water quality surrounding the Project site.

2.4 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.

2.4.1 Action and Limit Levels

The Action and Limit Levels of the construction waste are provided in Table 2.7.

Table 2.7: Action and Limit Levels of the 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

2.4.2 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 2.8.

Table 2.8: 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⁽²⁾ (m³)	Chemical Waste (kg)	Chemical Waste (L)	General Refuse (tonne)
Jan 2024	0	1,508	1,530	6,897	2,500	0	4,501
Feb 2024	0	486	82	5,373	0	600	3,383
Mar 2024	0	137	14,993	8,814	0	1,800	4,825
Apr 2024	0	131	3,058	4,959	0	0	4,875
May 2024	0	525	0	5,152	1,350	0	5,150
Jun 2024	0	16,018	0	4,390	60	1,300	6,789
Jul 2024	0	13,793	0	6,037	1,300	0	5,995
Aug 2024	0	4,719	0	8,961	0	2,400	7,121
Sep 2024	165	691	0	7,643	10	0	5,591
Oct 2024	293	14,738	0	7,395	0	2,400	5,959
Nov 2024	833	0	0	4,533	1,890	2,600	5,907
Dec 2024	353	0	0	6,284	800	0	7,893
Total	1,644	52,746	19,663	47,513	7,910	11,100	67,989
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, Construction and Demolition Material Reused in other Projects and Construction and Demolition Material Transferred to Public Fill in 2024 are updated.

Starting in 2018, the Project began reusing substantial inert Construction and Demolition (C&D) materials sourced from Government’s Public Fill Banks, including Tuen Mun Area 38 and Tseung Kwan O Area 137, for land formation works. This practice has been beneficial in maximizing the use of suitable public fill materials from Government’s Public Fill Banks for the Project. Following the commissioning of 3RS in November 2024, the importation of public fill materials from Government’s Public Fill Banks is no longer required for backfilling works. However, the C&D materials generated on-site continue to be reused. In 2024, the total volume of public fill imported was 997,831.5 m³. As of the end of 2024, the accumulative amount of public fill used for the Project reached 13,491,212.34 m³.

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.

2.4.3 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 excavation and treatment of all marine sediment excavated from areas with ground improvement works by DCM (refer to Section 2.4.3.1) were completed in February 2025. For areas without ground improvement works by DCM (refer to Section 2.4.3.2), the treatment and backfilling of all marine sediment were completed in 2022.

2.4.3.1 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 2.9 (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 2.9: 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 of the above tests 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 2.2 illustrates all the sampling grids covering the areas where marine sediment was excavated from the newly reclaimed land. 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 and the number of grids with marine sediment not encountered within the final excavation level are all summarised in Table 2.10. All the marine sediment sampling works within the reclaimed land area were completed in 2023. However, as there is no schedule that excavation will be required for the western portion of the T2 Concourse (T2C) until completion of the works, marine sediment sampling is not required for this area at present and will be subject to future development.

Table 2.10: Summary of Marine Sediment Testing Results for Sampling Grids within the Reclaimed Land Area with Excavation

Sampling Area	Western Vehicular Tunnel and Airport North Fire Station	Eastern Vehicular Tunnel	Terminal 2 Concourse (T2C)	APM/BHS Tunnel and Ancillary Building with Piled Foundation
Total No. of Grids for Areas where Marine Sediment was Excavated (a)+(b)+(c)	16	11	36	34
No. of Grids with “Pass” RBRGs Results (a)	15	7	34	30
No. of Grids with “Fail” RBRGs Results (b)	0	0	2	3
No. of Grids with Marine Sediment Not Encountered within the Final Excavation Level (c)	1	4⁽¹⁾	0	1
Total No. of Grids for Areas where Excavation or Marine Sediment Sampling is not Required under Current Status	0	0	14⁽²⁾	0
Notes: 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 completion of the works. Therefore, no marine sediment sampling or excavation is required for this area under current status.

2.4.3.1.1 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. Out of the total of 16 sampling grids for WVT and Airport North Fire Station, 1 sampling grid was recorded with no marine sediment encountered within the final excavation level and the testing results of the remaining 15 sampling grids passed all the RBRGs limits.

Western Vehicular Tunnel

The 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 was encountered within the final excavation level. Therefore, no marine sediment was generated from the works carried out by Contract 3310. For Contract 3303, there were 14 sampling grids, and all the testing results passed the RBRGs limits. A total of 508,506 m³of treated marine sediment were backfilled, and the backfilling locations are shown in Figure 2.3. The marine sediment excavation, treatment and backfilling works were completed in this area in 2024.

Airport North Fire Station

The construction of Airport North Fire Station was covered by Contract 3303. There was 1 sampling grid for this area, and the testing results passed all the RBRGs limits. A total of 9,269 m³of treated marine sediment were backfilled. The backfilling location is shown in Figure 2.3. The marine sediment excavation, treatment and backfilling works were completed in this area in 2024.

2.4.3.1.2 Eastern Vehicular Tunnel and Terminal 2 Concourse

The construction activities of Eastern Vehicular Tunnel (EVT) and Terminal 2 Concourse (T2C) were covered by Contracts 3310 and 3408 and 3405. Out of the total of 47 sampling grids for EVT and T2C, 4 sampling grids were recorded with no marine sediment encountered within the final excavation levels, 2 sampling grids with Arsenic exceeding the corresponding RBRGs limit were recorded and the testing results of the remaining 41 sampling grids passed all the RBRGs limits.

Eastern Vehicular Tunnel

The construction of EVT was covered by Contracts 3310 and 3408. For Contract 3310, there was 1 sampling grid, and the testing result indicated no marine sediment was encountered within final excavation level. Therefore, no marine sediment was generated from Contract 3310. For Contract 3408, out of a total of 10 sampling grids, 3 sampling grids were recorded with no marine sediment encountered within the final excavation level and the testing results of the remaining of 7 sampling grids passed all the RBRG limits. The marine sediment excavation and treatment works were completed in this area in 2024. A total of 11,305 m³ of treated marine sediment were stockpiled properly at the 3RS Project site area awaiting backfilling and the backfilling location will be reported in the next annual report.

Terminal 2 Concourse

The construction of T2C was covered by Contract 3405. Out of the total of 36 sampling grids, 2 sampling grids were recorded with Arsenic exceeding the corresponding RBRGs limit and the testing results of the remaining 34 sampling grids passed all the RBRG limits. A total of 152,168 m³ of treated marine sediment, which includes the marine sediment that passed all the RBRGs limits and the marine sediment that exceeded RBRGs limit for Arsenic but had undergone environmental treatment, were backfilled and the backfilling locations are shown in Figure 2.3. The marine sediment excavation, treatment and backfilling works were completed in this area in 2024.

There is no schedule that excavation will be required at the western portion of the T2C until completion of the works. Therefore, marine sediment sampling is not required for this area under the current status. This would, however, be subject to any future development programme at this area.

2.4.3.1.3 APM / BHS Tunnel and Ancillary Buildings with Piled Foundations

The construction activities of APM / BHS Tunnel and Ancillary Buildings with Piled Foundations were covered by Contracts 3802, 3804 and 3805. Out of the total of 34 sampling grids for such areas, 1 sampling grid was recorded with no marine sediment encountered within the final excavation level, 3 sampling grids were recorded with Arsenic exceeding the corresponding RBRGs limit and the testing results of the remaining 30 sampling grids passed all the RBRGs limits.

APM / BHS Tunnel

The construction of APM/ BHS Tunnel was covered by Contract 3802. Out of 33 sampling grids completed under this contact. 1 sampling grid was recorded with no marine sediment encountered within the final excavation level, 3 sampling grids were recorded with Arsenic exceeding the corresponding RBRGs limit and the testing results of the remaining 29 sampling grids passed all the RBRGs limits. Up to this reporting period, a total of 848,667 m³ of treated marine sediment, including the marine sediment that passed all the RBRGs limits and the marine sediment that exceeded RBRGs limit for Arsenic but had undergone environmental treatment, were backfilled and the backfilling locations are shown in Figure 2.3. Additionally, 145,444 m³ of treated marine sediment is properly stockpiled at 3RS Project site area, awaiting backfilling and the backfilling location will be reported in the next annual report.

At the time of preparing this report, further excavation of marine sediments from Contract 3802 took place in January and February 2025. During this period, a total of 4,308 m³of treated marine sediment which passed all the RBRGs limits were backfilled and the backfilling locations are shown in Figure 2.3. Accordingly, the marine sediment excavation and treatment works were completed in this area in February 2025.

Ancillary Buildings with Piled Foundations

The construction activities of East Fire Station and Landside Fire Station were covered by Contract 3804. There was 1 sampling grid that was done by Contract 3804 and the testing result of the grid passed all the RBRGs limits. However, the excavation areas for East Fire station and Landside Fire Station spread over a total of 6 sampling grids, which include 5 sampling grids done by Contract 3802, namely, 3802-BHS/APM-Grids 6, 18, 19, 20 & 21, and 1 sampling grid done by Contract 3804, namely, 3804-EFS-Grid 34 (refer to Figure 2.2). Out of these 6 sampling grids, 1 sampling grid was recorded with Arsenic exceeding the corresponding RBRGs limit and the testing results of the remaining 5 sampling grids passed all the RBRGs limits. Up to this reporting period, a total of 321 m³oftreated marine sediment, which includes the marine sediment that passed all the RBRGs limits and the marine sediment that exceeded RBRGs limit for Arsenic but had undergone environmental treatment, were backfilled, and the backfilling locations are shown in Figure 2.3. The marine sediment excavation and treatment works were completed in this area in 2024. However, another 6,933 m³ of treated marine sediment were stockpiled properly at 3RS Project site area awaiting backfilling and the backfilling location will be reported in the next annual report.

The construction of New Airport District Police Operational Base was covered by Contract 3805. The excavation area for New Airport District Police Operational Base spreads over a total of 4 sampling grids that were done by Contract 3802, namely, 3802-BHS/APM-Grids 11, 13, 32 & 33 (refer to Figure 2.2), and the testing results of all these 4 sampling grids passed the RBRGs limits. Up to this reporting period, a total of 5,162 m³ of treated marine sediment were backfilled, and the backfilling location is shown in Figure 2.3. The marine sediment excavation and treatment works were completed in this area in 2024. However, another 12,046 m³ of treated marine sediment were stockpiled properly at 3RS Project site area awaiting backfilling and the backfilling location will be reported in the next annual report.

2.4.3.1.4 Summary of Backfilling of Marine Sediment within the Reclaimed Land Area

The backfilling locations of treated marine sediment, denoted by specific colours according to the excavation areas, are shown in Figure 2.3. A summary of the backfilling volumes, along with the status of marine sediment from different excavation areas, is presented in Table 2.11.

Table 2.11: Summary of Backfilling Status of Marine Sediment within the Reclaimed Land Area

Area	Western Vehicular Tunnel and Airport North Fire Station	Eastern Vehicular Tunnel	Terminal 2 Concourse	APM/BHS Tunnel	Ancillary Building with Piled Foundation
Contract No.	3303 and 3310^(a)	3408 and 3310^(a)	3405	3802	3804 and 3805
Volume of Treated and Backfilled Marine Sediment, m³	508,506 + 9,269 = 517,775	0	152,168	848,667 + 4,308 = 852,975^(b)	321 + 5,162 = 5,483
Volume of Treated Marine Sediment awaiting backfilling, m³	0	11,305	0	145,444	6,933 + 12,046 = 18,979
Status	Excavation, treatment and backfilling works completed in 2024.	Excavation and treatment works completed in 2024. Backfilling to be completed.	Excavation, treatment and backfilling works completed in 2024.	Excavation and treatment works completed in February 2025. Backfilling to be completed.	Excavation and treatment works completed in 2024. Backfilling to be completed.

Notes:

(a) No marine sediment was generated from Contract 3310.

(b) This volume includes the treated and backfilled marine sediment completed in 2024 (848,667 m³) as well as the treated and backfilled marine sediment completed in January and February 2025 (4,308 m³).

2.4.3.2 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 2.9. 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 2.4.3.1. 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.

As presented in the previous Annual EM&A Report No. 8, the marine sediment excavation, treatment and backfilling works for the areas without ground improvement works by DCM were completed in 2022 and there was no update during this reporting period. The following sections provide a summary on the volumes of excavated, treated and backfilled marine sediments for different areas as excerpted from the Annual EM&A Report No. 8.

2.4.3.2.1 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. The marine sediment excavation, treatment and backfilling works were completed in this area in 2022. A total of 117 m³of excavated and treated marine sediment were backfilled and the backfilling location is shown in Figure 2.3.

2.4.3.2.2 T2 Foundation and Substructure Works

Marine sediment was excavated and treated with cement stabilisation by Contract 3503. A total of 72 m³ of excavated and treated marine sediment were backfilled and the backfilling locations are shown in Figure 2.3. The marine sediment excavation, treatment and backfilling works were completed in this area in 2022.

2.4.3.2.3 Approach Light Area

The marine sediment generated from Approach Light Area was covered by Contract 3303. A total of 2,404 m³ of excavated and treated marine sediment were backfilled and the backfilling location is shown in Figure 2.3. The marine sediment excavation, treatment and backfilling works were completed in this area in 2022.

2.5 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 and was completed in December 2024. 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 post-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 post-construction phase monitoring effort over a 12-month period from January 2024 through December 2024, 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 post-construction phase of the Project, has also been reviewed.

This reporting period is effectively a full year of post-construction phase monitoring of CWDs. This annual report reviews the post-construction phase monitoring data for 2024 and compares it with the construction phase monitoring data for the previous years.

CWD monitoring was conducted by undertaking vessel line-transect surveys. 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 2.4.

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 E for the location of this additional survey), which is an area that historically had CWDs in the outer bay, to establish a more comprehensive understanding of CWD distribution and 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.

2.5.1 Summary of Monitoring Results

2.5.1.1 Summary of Vessel Line-transect Survey Monitoring Results

2.5.1.1.1 Survey Effort

During the reporting period from January 2024 to December 2024, 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 5391.2 km survey effort was collected in this reporting period.

Around 93.3% (5029.8 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 E. A detailed record of the survey effort data is also provided in Appendix E.

2.5.1.1.2 Sighting Distribution

During the reporting period, a total of 151 groups consisting of 490 CWDs were sighted in NWL, AW, WL and SWL survey areas during on-effort surveys. Among all these sighting, 149 groups with 483 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 sightings were excluded from analysis in the following sections. Breakdown of the sightings by survey areas are tabulated in Table 2 of Appendix E.

In NWL (including AW transects), six CWD sightings were recorded, accounting for 4% of the total sightings. These sightings were mainly scattered within and around the western waters of the airport, along with a single sighting at the northern waters of Lung Kwu Chau. Compared to 2023, there were fewer sightings in the waters within and around SCLKCMP and also the west of the airport.

In WL, 100 CWD sightings were recorded, accounting for 66% of the total sightings. CWD sightings were recorded on almost all transects. The sightings were distributed quite evenly over the entire survey area, particularly between Tai O and Fan Lau.

In SWL, 45 CWD sightings were recorded, accounting for 30% of the total sightings. Sightings of CWDs were scattered over 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 gradually 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 E.

2.5.1.1.3 Density and Abundance Estimation

Line-transect analysis to estimate the density and abundance of CWDs in Hong Kong waters during the reporting period was conducted using the same basic methods as in previous analyses (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). Although it was experimented with Beaufort sea state as a co-variate, for 2024 the best estimate of abundance was obtained using Conventional Distance Sampling and a hazard rate model with a cosine adjustment (effective strip width = 192 m). The detection function of 3RS CWD monitoring data of this reporting period is shown in Figure 2 of Appendix E and the various parameters of the 2024 estimates are shown in Table 3 of Appendix E. The overall abundance estimated for this reporting period (incorporating an entire year of data from all four seasons) was 60 CWDs (CV = 21.9%, just above what is considered a good level of precision of <20%). This is substantially higher than estimates from the last three years (i.e., 2021 to 2023). For comparison, the 2023 estimate was 40 CWDs (CV= 14.4%), the 2022 estimate was 35 CWDs (CV = 15.8%), the 2021 abundance was 34 CWDs (CV = 16.5%). As in all recent years, the area with the highest abundance and density in 2024 was WL (N=44, D=135/100 km²; this has been consistent over the AFCD long-term records that WL has been the area with the highest CWD abundance and density). NWL showed similarly low numbers of dolphins from the previous year (1 in 2024 and 4 in 2023), though SWL showed an increase (from 5 to 15). The CWD densities in NWL and SWL were 1 and 22 individual(s) per 100km²respectively. 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. Although the increase in abundance estimated in 2024 may indicate the beginnings of a recovery (after dolphins moved away from the 3RS works area in past years), we are not yet seeing signs of a strong recovery in numbers north of Lantau Island. The drop of CWD abundance in NWL since about 2010 is thought to be partly related to the impacts from the construction of the Hong-Kong-Zhuhai-Macao Bridge (HZMB) (Jefferson 2018 and Huang et al. 2024). 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 and establishment of the North Lantau Marine Park, which came into effect in November 2024.

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 3 of Appendix E). The autumn estimate was the lowest (N=23 dolphins), with the summer estimate showed the highest numbers (N=104 dolphins). This is different from what has traditionally been the case for dolphin numbers in Hong Kong, where autumn is usually the high season and spring the low season. This may suggest that the environment is changing to the point that traditional patterns are being disrupted, but further years of data are needed on this point.

2.5.1.1.4 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 2024 to December 2024. SPSE and DPSE of the current reporting year and the previous reporting years are depicted in Figure 3 of Appendix E.

There was a decrease of CWDs’ usage of waters in NWL in 2024 compared to the previous year, with obviously less usage of waters around SCLKCMP while the usage of waters in the west of existing HKIA is similar to that of 2023. Following 2023, this is the second time that CWDs were absent from the western boundary of HKSAR in NWL.

The important dolphin habitats in WL survey area in 2024 are largely similar to 2023. 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 an increase of CWDs’ usage, reflected by both SPSE and DPSE, at the waters between Soko Islands and Lo Kei Wan in 2024 after a mild decline in 2023, 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 4 of Appendix E. 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.

2.5.1.1.5 Group Size

During the reporting period from January 2024 to December 2024, group size of CWDs ranged from one to 12 dolphins, with an average of 3.25, taking into account all on-effort CWD sightings recorded. The average group sizes of NWL, AW, WL and SWL were 3.20, 1.00, 3.34 and 3.09 respectively. By four solar seasons, the average group size of CWDs was the highest in winter (3.80) but the lowest in spring (2.59). The summaries of the average group size of CWDs by survey area and by season are presented in Table 4 and Table 5 of Appendix E.

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 2024 with around 58.3% and 37.1% of all on-effort sightings respectively. Seven sightings, which accounted for 4.6% 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 and the eastern SWL survey area. Large-sized CWD groups were recorded in NWL, WL and SWL survey areas, particularly near Fan Lau. The sighting distribution of CWDs with different group sizes is illustrated in Figure 5 of Appendix E.

2.5.1.1.6 Activities and Association with Fishing Boats

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. However, behaviour and activity data are useful in gauging where and how dolphins are spending their time, with short and longer term (inter-year) comparisons of potential changes, and therefore continue to be collected from the vessel surveys.

During the reporting period, a total of 37, 22, 24 and 4 groups of CWDs were observed engaging in foraging, travelling, socialising and resting/milling activities, comprising of 25%, 15%, 16% and 3% of all on-effort CWD sightings respectively. The sighting locations of CWD groups engaged in different types of activities are depicted in Figure 6 of Appendix E while the percentages of different activities for each of the survey areas are shown in Table 6 of Appendix E.

In NWL, both foraging and traveling activities occurred at the southwestern corner of the survey area while another sighting with foraging activity was recorded at the northeastern water outside of SCLKCMP. In NWL, 40% of CWD sightings were engaged in feeding activity, which was higher compared to the previous year (20% in 2023).

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 CWD sightings engaged in milling/resting activities were also recorded at the northern tips of the WL survey area and at waters near Yi O and Fan Lau. In WL, 21% of CWD sightings were engaged in feeding activity, which is slightly lower than the 26% recorded in 2023.

In SWL, the sightings with observed activities were scattered through the entire survey area, between Lo Kei Wan and Fan Lau. Travelling activities mainly occurred near Fan Lau Tung Wan, with a sighting occurring in the northern waters of Soko Island. About 29% of the CWD sightings in the survey area were engaged in feeding activity, which is slightly lower than that recorded in 2023 (i.e. 34%).

A total of 10 sightings of CWDs were observed associating with operating fishing boats, including gill netters (four groups) and purse seiners (six groups), accounting for 6.6% of all on-effort sightings in 2024. CWDs’ association with operating fishing boats in 2024 showed a minor drop compared to that of last year (6.9% in 2023).

Observations of CWD association with operating fishing boats were scattered in WL and SWL. In WL, association with gill netters and purse seiners scattered throughout the northern waters of Peaked Hill. While in SWL, associations with operating purse seiners were mainly observed in waters between Fan Lau Tong Wan and Tai Long Wan, two sightings in association with an operating gillnetter were observed along the coastal water of Fan Lau and Lo Kei Wan. The sighting locations of CWD groups associated with an operating fishing boats are depicted in Figure 7 of Appendix E.

2.5.1.1.7 Mother-calf / Mother-unspotted Juvenile Pairs

During the reporting period, a total of 25 sightings were observed of mother-and-unspotted calf (UC), mother-and-unspotted juvenile (UJ) and/or mother-and-mottled pairs, which accounted for about 15.6% of all on-effort sightings of 2024. The sighting number was lower than that of 2023 (30 sightings). For different survey areas, the percentages of sightings with mother-calf pairs in NWL, WL and SWL were 20%, 18% and 13.3% 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.

Amongst the abovementioned 25 sightings, three sightings were observed with the presence of mother-and-UC, 20 sightings were observed with the presence of mother-and-UJ and two sightings were observed with the presence of both mother-and-UC and mother-and-UJ. According to the results of photo-identification, a total of seven mother-calf pairs were successfully identified from these 25 sightings.

Most of the sightings with the presence of mother-calf pair were recorded in WL between Yi O and Fan Lau. In NWL, one sighting with mother-calf pairs was recorded to the west of the existing airport. In SWL, six sightings with the presence of mother-calf pairs were scattered in waters between Fan Lau and the Soko Islands. The sighting distribution of mother-calf pairs is depicted in Figure 8 of Appendix E.

2.5.1.1.8 Photo Identification – Summary

In 2024, a total of 13 newly identified CWD individuals were added to the photo-identification catalogues, including four animals added to NL catalogue and nine animals added to WL catalogue.

A total of 104 CWD individuals were identified for altogether 269 times from all sightings in 2024. Amongst these 104 CWD individuals, 20, 62 and 22 belonged to NL, WL and SL catalogues respectively. There were 61 individuals (around 58.7%) that were sighted more than once. Fourteen of these 61 re-sighted individuals were sighted five times or more.

The most frequently re-sighted animals in 2024 were SLMM003 which was sighted 11 times, followed by WLMM001 and SLMM052 (both being re-sighted 9 times). SLMM003 was also one of the most frequently re-sighted animals of the previous reporting year (i.e. being sighted for 11 times in 2023). Since the establishment of the photo-identification catalogue, the most frequently re-sighted animal is SLMM014 which has been sighted 78 times, followed by SLMM003 (being sighted 75 times), SLMM037 (being sighted 66 times) and WLMM001 (being sighted 65 times). There are a few more animals including NLMM013, WLMM007, WLMM027, WLMM028, WLMM029, WLMM043, WLM056, WLMM065, WLMM071, WLMM079, WLMM114, WLMM131, SLMM002, SLMM007, SLMM010, SLMM012, SLMM023, SLMM031, SLMM044, SLMM049 and SLMM052, that have been sighted 30 times or more.

Thirty-nine animals that appeared in Hong Kong waters in previous years (with 10 or more re-sighting records since the commencement of the monitoring in mid-December 2015) did not appear in our sighting records in 2024 (note that these dolphins may still be using Hong Kong waters, but may have not been detected from our surveys). These animals are NLMM001, NLMM002, NLMM004, NLMM006, NLMM009, NLMM010, NLMM015, NLMM016, NLMM018, NLMM019, NLMM021, NLMM040, NLMM041, NLMM043, SLMM011, SLMM012, SLMM015, SLMM017, SLMM022, SLMM028, SLMM044, SLMM045, SLMM053, SLMM059, SLMM064, WLMM006, WLMM013, WLMM019, WLMM030, WLMM054, WLMM060, WLMM062, WLMM076, WLMM078, WLMM081, WLMM086, WLMM090, WLMM107 and WLMM149. Some of these 39 individuals (i.e. NLMM002, NLMM004, NLMM006, NLMM010, NLMM018, NLMM019, NLMM043, SLMM011, SLMM015, SLMM017 SLMM028, SLMM045, SLMM053, WLMM006, WLMM054, WLMM060, WLMM078, WLMM090 and WLMM107) have not been seen in Hong Kong waters for three or more years. It could not be confirmed that if these animals were occurring elsewhere in mainland waters, or if some of them have already died.

On the other hand, some dolphins (with 10 or more re-sighting records since the commencement of the monitoring in 2015) that disappeared for two or more years have returned to Hong Kong waters in 2024. These dolphins include NLMM012, WLMM008 and WLMM009.

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 again during vessel surveys for four years since 2021.

On 12 October 2024, a fresh dolphin carcase was reported at the waters near Yi O. As per our request, AFCD kindly shared the dorsal fin photos of the carcase taken by Ocean Park Conservation Foundation before undergoing necropsy. Identification work against our CWD photo identification catalogue was then conducted and it was confirmed that the carcase belongs to SLMM010 who was being tracked by 3RS dolphin monitoring since Dec 2015. SLMM010 was sighted for a total of 58 times and was the 3rd most frequently re-sighted animals of our photo-identification database up to 2023. Also, it was one of the only 14 year-round residents defined from our photo-identification analysis. The last encounter of SLMM010 was on 13 Aug 2024 at the coastal waters between Yi O and Peaked Hill and which was also the only sighting of SLMM010 in 2024.

A summary of the photo-identification records of CWDs is presented in Table 7 of Appendix E.

2.5.1.1.9 Photo Identification – Range Use of Identified CWD individuals

SLMM003, the most frequently re-sighted animal in 2024 and also the 2^nd most frequently re-sighted animal since mid-December 2015, continued to occur frequently in WL and SWL waters. Compared to 2023, SLMM003’s range use in 2024 extended slightly from Peaked Hill to Yi O in the northern end range use in WL and extended east in SWL from the middle part of the survey area to Lo Kei Wan.

Similar to SLMM003, WLMM001, the second most frequently re-sighted animal in 2024 continued to occur frequently in WL and SWL waters and has a range use that extended northern in WL and eastern in SWL compared to 2023.

SLMM052, another 2^nd most frequently re-sighted animal in 2024 continued to occur frequently in WL and SWL waters. Compared to 2023, SLMM052’s range use in WL extended to the north from Yi O to Tai O while the extent of range use in SWL remained similar. However, its range use in SWL when compared to earlier years from 2015 to 2022, shrank quite considerably in the eastern end of SWL from Soko Islands and Lo Kei Wan in earlier years to only the middle part of the survey area in recent two years.

SLMM014, the most frequently re-sighted animal since the establishment of the photo-identification catalogue, continued to frequently utilize WL and SWL waters. Continuing from 2023, the northern end of SLMM014’s range use in WL shrank again from Yi O to Peaked Hill. When compared with earlier years from 2015 to 2022, SLMM014’s range in western waters showed a distinct decrease. It was not sighted from the waters north of Yi O for two consecutive years. On the other hand, SLMM014’s range use in SWL covers the entire survey area and remained stable over the years.

The sighting locations of SLMM003, WLMM001, SLMM052 and SLMM052 are depicted in location maps under Figure 9 of Appendix E, which provide the indicative distribution range use of representative individuals recorded from the 3RS CWD monitoring.

2.5.1.1.10 Photo Identification – Cross-area Movement

Amongst the 61 individuals that were re-sighted more than once in 2024, 37 individuals showed cross-area movement between survey areas. This accounted for about 34.3% of all 108 identified animals in 2024. Amongst these 37 animals, 6 animals (16.7%) were re-sighted in both NWL (including AW) and WL, 31 animals (83.8%) were recorded in both WL and SWL. There were no animals recorded occurring in all three main survey areas (WL, SWL and NWL) in 2024.

2.5.1.1.11 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 2024, photo-identification records of 70 dolphin individuals that have at least 15 re-sightings since the establishment of the database were examined. There are 13 animals namely SLMM002, SLMM003, SLMM007, SLMM010, SLMM014, SLMM023, SLMM037, SLMM044, SLMM052, WLMM001, WLMM007, WLMM056 and WLMM079 being defined as year-round residents. However, one of these 13 year-round residents, SLMM010, was confirmed dead in October 2024 as mentioned in Section 2.6.2.1.9. One animal, namely NLMM001 was defined as a seasonal resident. Fifty animals were considered as seasonal residents. Five individuals, namely NLMM002, NLMM004, NLMM006, SLMM011 and WLMM006 are considered as seasonal visitors to Hong Kong waters. However, it is noted that the low number of dolphins being classified as visitors at present is mainly because of the 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 70 animals are shown in Appendix E.

2.5.2 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. The 12 months post-construction phase monitoring was completed between January and December 2024.

Vessel Line-transect Survey and Photo-identification

From the CWD vessel-based monitoring data, the estimate of overall abundance for 2024 was 60 dolphins, which is considerably higher than the year before, with a CV of 21.9% (which indicates a reasonable level of precision) even though the actual number of dolphins encountered in 2024 (i.e., 149) is slightly lower than that in 2023 (i.e., 160). This might seem counterintuitive, but it is due to the way line-transect distance sampling uses statistical techniques to estimate the dolphin population based on the sightings recorded. The number of sightings/dolphins is only one component of the abundance estimate using line-transect distance sampling method. Other components include: survey effort under different weather conditions, group size of the sightings, distance of the sightings to the transects (i.e. Perpendicular Sighting Distance PSD) and detection probability. These components are influenced by many factors, such as dolphin behavior (dolphins may change their behavior or distribution, making them less or more visible during the survey), and environmental and survey conditions (e.g., water, weather, and sea conditions, food availability, or human activities that all influence dolphin visibility and distribution). While the number of sightings/dolphins only tells us how many dolphins we saw during the survey, line-transect distance sampling takes into account the probability of detecting dolphins at different distances from the transect line. This helps to correct for dolphins that are present but not seen during the survey, providing a better understanding of the true population size and its changes over a long period of time. Therefore, even with fewer sightings/dolphins, line-transect distance sampling could still estimate a higher number of dolphins based on the inclusion of different factors. For example, one potential factor leading to a larger estimated CWD abundance in 2024 with fewer dolphin sightings compared to 2023 may be the comparatively lower survey effort under favourable weather conditions (i.e. Beaufort 0-3 and visibility of approximately 1200 m or beyond, 5029.8 km in 2024 vs 5234.8 km in 2023). Another potential factor is the smaller average PSD of 2024 compared to 2023 (i.e. 225.9 m vs 237.6 m) indicted that there were potentially more CWD sightings sighted closer to the transect lines in 2024. When more sightings are concentrated closer to the transect lines, the detection function becomes steeper, meaning the model assumes that animals farther away are much less likely to be seen. This may lead to an estimate of higher dolphin density and thus higher abundance.

It is observed that the estimate of total dolphin numbers in Hong Kong was higher than the previous year’s estimate (40 dolphins in 2023, CV = 14.4%), though a change from one year to the next should never be taken as an indication of long-term trends. The seasonal analysis showed that during summer, dolphin numbers are somewhat higher in Hong Kong waters (104 dolphins). The 2024 seasonal range is 23 to 104 dolphins. The autumn estimate was the lowest (23 dolphins), while the summer estimate was the highest (104 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 100 dolphins estimated to be present in Hong Kong in the summer wet season months.

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. 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 some time after the NLMP came into effect, which happened in late 2024.

Within NWL waters, CWDs have recently been mostly found in the western water of the airport Island. A total of 6 dolphin sightings were made (in favourable weather conditions) in NWL including AW transects in 2024, indicating that, there is still not yet a substantial return of CWDs to this area. 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 or above 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 been the highest 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 between 2019 and 2022, followed by a rebound in 2023 and 2024. The cause of this decline has yet to be investigated, and although there is a rebound in the recent two years, the abundance of CWDs in WL survey area should be closely monitored.

In earlier years, concerns had been expressed by some stakeholders that dolphin numbers in NWL may have decreased 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 did not continue in 2019-2024. 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 now that the new marine park has gone 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 104 CWD individuals were identified for altogether 269 times from all sightings in 2024, with 61 individuals (around 58.7%) sighted more than once. Amongst the 61 individuals that were re-sighted more than once in 2024, 37 individuals showed cross-area movement between survey areas. This accounted for about 34.3% of all 108 identified individuals in 2024. There were dolphins showing cross-area movement either between NWL-WL and WL-SWL but none showing cross-area movement between NWL-SWL or occurred 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. However, such increase did not continue in 2024. The number of dolphins showing cross-area movement involving NWL dropped to six in 2024, back to the level of year 2020. The most frequently re-sighted animals in 2024 were SLMM003 which was sighted 11 times, followed by WLMM001 and SLMM052 (both being re-sighted 9 times). Thirteen identified dolphins were considered as year-round residents of Hong Kong waters in view of their occurrence pattern in all seasons for consecutive years. SLMM010, one of the year-round resident, was confirmed dead in October 2024.

2.5.3 Conclusions of CWD Monitoring Results

With reference to the aims of post-construction phase CWD monitoring described in the EM&A Manual (Section 10.2.1.2-4), the key findings of CWD monitoring in 2024 are summarised as follows.

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

The latest monitoring data indicates an increase in overall CWD population, but mixed trends in use of areas within Hong Kong waters in 2024, 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 30 to 44 CWDs). SWL also showed an increase from 5 to 15. As expected and predicted in the 3RS EIA, dolphins likely shifted their activities away from the 3RS construction activities as well as the 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 such as foraging and resting, despite the disturbance. Whether a possible increases observed from 2021-2024 indicate the beginning of a long-term dolphin recovery in Hong Kong awaits more years of similarly-gathered data. An important presently unanswered question is how much recovery there will be since marine construction activities have ended in this area, and the new marine park has come into effect. Continuous monitoring efforts in the 3RS operation phase will help to elucidate this important question.

Effectiveness of the HSF Speed and Routing Restrictions to the CWDs

As detailed above, there are nine years of data from the period since the SCZ was implemented, and the information available from both the vessel-based and the past 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 but resumed in 2023 and 2024 (refer to Section 2.9 and Table 2.19), while the dolphin abundance in NWL fluctuated between 2022 and 2024. Observations in 2024 is still in 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.

Trends in Long Term Monitoring Data

From vessel surveys conducted, though there appears to be a continuous uptick in numbers in 2022-2024 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 started in 1995/1996. It is estimated that 60 CWDs (on average) were found within Hong Kong waters in 2024, which is up considerably from the last three years (i.e. 40 CWDs in 2023, 35 CWDs in 2022, and 34 CWDs in 2021). Seasonally, the CWD numbers within Hong Kong ranged from about 23-104 in 2024.

The increase of CWDs abundance in NWL in 2023 did not continue in 2024, but it is not pessimistic as the overall dolphin abundance in Hong Kong waters is up considerably in 2024. Continuous effort should be allocated to monitoring the potential recovering trend particularly in North Lantau waters where the newly established NLMP is located. Theodolite tracking data will not be gathered in immediate future due to the low detection of CWDs by this monitoring method, resulting in a lack of adequate survey data for conducting a robust analysis. Thus, no assessment of CWD behavior or fine-scale movement patterns in this former hotspot of dolphin activity are possible. Such arrangement has been agreed by the EPD and are in compliance with EM&A Manual. Should there be an increase in numbers in these former theodolite tracking areas, particularly north off LKC, such observations from shore may be re-initiated by AAHK to facilitate important long-term comparisons of behavioral data, including further information on dolphin reactions to human activities (Piwetz et al. 2015; Würsig et al. 2016).

It is important to remember that dolphins shift around within their habitat from year to year, due to both natural and anthropogenic factors. Thus, short-term monitoring data of CWDs is insufficient to indicate the full picture of 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 changing over time.

The CWD construction and post-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, and the increase in abundance in 2021-2024 is encouraging .

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 when the estimated CWD abundance by 3RS construction phase CWD monitoring reached the lowest (i.e. 32 dolphins) 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). Operational phase CWD monitoring for the 3RS is ongoing for the whole of 2025 (after the designation of NLMP in late 2024), with AAHK’s Rebound Survey then continuing until around 2030 to monitor trends in dolphin abundance over this longer period. The Rebound Survey is an additional AAHK initiative for CWD monitoring beyond statutory requirements and this monitoring effort is expected to facilitate an evaluation of impacts over time and will help indicate if the Hong Kong CWD population stabilizes or increases in abundance in the future. An increase in numbers of Hong Kong CWDs is desirable for the long-term health of this population.

At this stage of the 3RS Project, all recommended mitigations have been implemented and although impacts were expected and have occurred, these were temporary and within previously predicted patterns. As land formation was completed in the first quarter of 2023, and the NLMP was designated and came into effect on 1 November 2024, the expectation is that the CWD population will stabilize or increase in the coming years. Patterns of CWD abundance will be kept under review over the next few years, as AA’s CWD Rebound Survey monitoring continues in the future.

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 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.

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 between 2019 and 2022. 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.

2.5.4 Site Audit for CWD-related Mitigation Measures

During the reporting period, teams of at least two dolphin observers were deployed by contractors for continuous monitoring of the Dolphin Exclusion Zone (DEZ) for armour rock laying works in accordance with the DEZ Plan. 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.

According to Section 10.6.2.2 of the Updated EM&A Manual, audits of HSF implementation measures and Spill Responses Plan implementation measures will be conducted once every three months and every six months respectively for one year upon operation of 3RS. The first audit of HSF implementation measures will be conducted in February 2025 and the first audit of the Spill Responses Plan measures will be conducted in May 2025.

2.6 Sewage Flow Monitoring

The annual sewage flow monitoring commenced in June 2021, with the objective of informing the timing for initial planning of sewer upgrading works, Given that AAHK has begun planning for construction phase, the annual monitoring was concluded in December 2022. Details of the daily average flows data are presented in Annual EM&A Report No.7.

2.7 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 2.12. 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 2.13. No non-conformity was recorded during the reporting period.

Table 2.12: 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 2.13: 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: For PM in Table 2.13, refers to Project Manager only.

2.7.1 The Implementation Status of the Environmental Protection Measures

The implementation status of the environmental protection measures is summarised below in Table 2.14. For trees which were managed by the Project during the reporting period, relevant measures have been implemented by Contracts 3508 and 3801.

Table 2.14: 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 was 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.	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 Contractor’s performance on the implementation of advanced hydroseeding works was observed and checked by the ET during the weekly site inspection.	3310
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:

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 comprising a number of detailed design contracts and numerous construction works contracts at different stages of design and construction. The works areas would be taken up by different 3RS works contracts in stages as construction advanced. The landscape and visual elements associated with these contracts of the 3RS Project would also be designed and implemented in phases throughout the duration of the Project.

Since the EIA stage, the proposed tree treatments were adjusted to reflect updated baseline conditions, such as damage from typhoons, and the availability of more detailed design information for project buildings and infrastructure. These treatment figures were subsequently revised and incorporated into the latest Landscape and Visual Plan.

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 approved 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 2.15. The tree schedule updated as of end 2024 is shown in Appendix G.

Table 2.15: Summary of the Number of Retained, Transplanted and To-be-transplanted Trees as of December 2024

Contract No.	Retained (nos.)	Transplanted (nos.)		To-be-transplanted (nos.)
		Establishment Period	Maintenance Period
3503⁽¹⁾	0	0	9	0
3508	24	0	12	0
3801⁽²⁾	0	0	5	0
Grand Total	24	0	26	0

Note:

1. 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.

2. 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 2.17.

Table 2.16 lists the affected tree ID together with the reasons for change of tree status between the tree schedules as of end 2023 and end 2024.

The total number of retained trees of the Project as of the end of 2024 was 24. Compared to 37 nos. of retained trees reported in the tree schedule as of the end of 2023, the change in number was due to the following reasons:

· Some trees under Contract 3801 were handed over to AAHK. (-3 nos.).

· A tree under Contract 3508 was found dead. (- 1 no.).

· Some trees were removed due to poor structural conditions or conflicting with an existing building. (-9 nos.).

Table 2.16: Summary of the Tree Status Changes between end 2023 and end 2024

Tree ID(s)	Contract	Status as of end 2023	Status as of end 2024	Remarks	Impacts to Total Tree Number
CT1885 CT1886 CT1887	3801	Retain	Retain	3 nos. of trees were handed over to AAHK in February 2024.	Retain: - 3 nos.
T1390A	3508	Retain	Fell	1 no. of tree was found dead and removed in June 2024.	Retain: - 1 no.
T1384A, T1385A, T1386A, T1387A, T1388A, T1389A, T1392A, A3, A4	3508	Retain	Fell	9 nos. of trees were removed in November 2024 due to poor structural conditions or conflicting with an existing building	Retain: - 9 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 2.17. Photos of the transplanted trees are presented in Table 2.18.

During the reporting period, the compensatory trees bi-monthly site inspections for 12-month establishment period were undertaken in February, March, April, May, June, July, September and November 2024.

Table 2.17: 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 2025.
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. The trees within the land parcel were acquired for construction of infrastructure. The trees were felled in 2023.
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 2025.
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 2025.
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 2.18: 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 (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

2.8 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 1113 sessions of site inspection and 201 sessions of ad-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.

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.

2.9 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 2.19.

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 2023-24 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 since 25 March 2020. In total, 259 ferry movements between HKIA SkyPier and Macau were audited in the reporting period. All audited 259 ferry movements travelled through the SCZ with average speeds of 15 knots or below, complying with the SkyPier Plan. One deviation case was recorded during the reporting period. This case, involving a ferry not entering or leaving the SCZ through the gate access points, was recorded in October 2024 and was due to strong tidal waves and currents.

According to EP Condition 2.10 and SkyPier Plan, the annual daily average limit and the maximum daily movement cap were to be implemented before the designation of NLMP on 1 November 2024. As a reault, this limit and cap ceased to apply after that date. From January to October 2024, the annual daily average of all SkyPier HSF movements was 53, which remained well within the annual daily average cap of 99 SkyPier HSF movements. During the same period, daily movements of all SkyPier HSFs ranged from 32 to 66 which is also within daily cap of 125 movements.

Table 2.19: Summary of Key Audit Findings against the SkyPier Plan

Key Audit Findings	Jan-24	Feb-24	Mar-24	Apr-24	May-24	Jun-24	Jul -24	Aug-24	Sep-24	Oct -24	Nov-24	Dec-24
Total number of HSF movements recorded and audited for HSF to/from Macau	20	18	26	25	28	26	34	21	22	23	9	7
Use diverted route and enter / leave SCZ through Gate Access Points	20	18	26	25	28	26	34	21	22	22	9	7
No. of SkyPier HSFs in compliance with average speed within 15 knots in SCZ	20	18	26	25	28	26	34	21	22	23	9	7
Range of daily movement (capped daily average of 99 for all SkyPier HSFs)	48-54	43-51	40-53	40 -55⁽¹⁾	48-55⁽¹⁾	40-54	50-62	54-60	11-60	55-66	N/A	N/A

Source: Excerpted from Monthly and Quarterly EM&A Reports

Remark: (1) Updated figures were provided by AAHK.

2.10 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 Automatic Information System (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 4 skipper training workshops were held by ET during the reporting period with 6 skippers / captains of construction vessels associated with the 3RS contracts to familiarise them with the predefined routes, provide general education on local cetaceans, outline guidelines for minimising adverse water quality impact, detail the required environmental practices / measures and safety measures for operating construction and associated vessels in the presence of CWDs. In addition, 18 skipper training workshops were held by contractors’ Environmental Officers with 37 skippers / captains and competency tests were conducted subsequently with the trained skippers / captains by ET to access the trainee’s understanding and readiness. 2 skipper refresh training sessions were held by ET for the contractors’ Environmental Officers and skippers / captains to ensure they were familiar with the predefined routes and the required environmental practices / measures for the designation of NLMP on 1 November 2024. Furthermore, ET participated in Marine Management Liaison Group meetings to assist in resolving any marine-related issues encountered during the Project.

2.11 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 2024.

2.11.1 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 150 members involving district councillors and community leaders. In 2024, a meeting cum airport visit was held in June and other meeting was held in December. 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 meetings.

2.11.2 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 2024, a meeting cum airport visit was held in July. 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 2024, a meeting cum airport visit was held in July.

2.11.3 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 2024, a meeting was held in June.

2.11.4 Other Stakeholders

The AAHK attended a Legislative Council Panel on Economic Development meeting in May 2024 to share with members updates on the development of the 3RS Project and attended another meeting in October 2024 to update members on the preparatory work for the commissioning of the 3RS and emergency response mechanism of HKIA. Furthermore, the AAHK submitted a paper to the Advisory Council on the Environment (ACE) in July 2024 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. Three enquiries were received via the telephone hotline and twenty-four enquiries were received via the dedicated email in 2024.

2.12 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.

2.13 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

Ten environmental complaints were received in the reporting period, seven of which were related to air quality, one on noise and two on light nuisance. The ET conducted investigations on all of them in accordance with the Manual and the Complaint Management Plan. A summary of the complaints and analyses is presented in Appendix F.

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 F.

4 Conclusion and Recommendation

The new North Runway was commissioned in November 2022. Following the completion of reconfiguration works on the Centre Runway, the 3RS was commissioned on 28 November 2024. Meanwhile, expansion of the T2, construction of the T2C, installation of a new automated people mover system and baggage handling system, as well as construction of airport support infrastructure, utilities and facilities are ongoing.

The NLMP was designated on 1 November 2024. The NLMP connects with the adjacent SCLKCMP and the BMP. Together, these three marine parks form a contiguous network of marine protected areas covering approximately 4,570 hectares. This interconnected system enhances the protection of important habitats, particularly for the Chinese White Dolphin.

During the reporting period from 1 January 2024 to 31 December 2024, 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, waste monitoring, and landscape and visual monitoring and environmental site inspections for the Project’s construction works.

The monitoring results in relation to the construction dust, construction noise and construction waste did not trigger their corresponding Action or Limit Levels during the reporting period.

Following the commissioning of 3RS in November 2024, the importation of public fill materials from Government’s Public Fill Banks is no longer required for backfilling works. However, the C&D materials generated on-site continue to be reused. In 2024, the total volume of public fill imported was 997,831.5 m³. As of the end of 2024, the accumulative amount of public fill used for the Project reached 13,491,212.34 m³.

The excavation and treatment of marine sediment were completed in February 2025. The remaining treated marine sediment were stockpiled properly at 3RS Project site area, awaiting backfilling.

A total of around 5391.2 km survey effort was conducted for the vessel line-transect monitoring for CWDs during the 12-month post-construction phase monitoring period. A total of 151 groups of 490 CWDs were sighted in NWL, AW, WL and SWL survey areas. No CWDs were recorded in the NEL survey area. Overall abundance of CWD in Hong Kong western waters was estimated at 60 dolphins in 2024 from line-transect analysis. According to the Updated EM&A Manual, an operation phase CWD monitoring by vessel line-transect survey would be carried out for a period of 12 months, starting from January 2025, to estimate the CWD abundance and continue the evaluation of the potential rebound of CWD abundance in Hong Kong.

On the implementation of DEZ Plan, dolphin observers were deployed by the contractors for continuous monitoring of the DEZ for 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. As for DEZ monitoring records, no dolphins or other marine mammals were observed within the DEZs in this reporting period.

In accordance with Section 6.2.1.2 of the Manual, the routine monitoring of H₂S levels for the sewerage system of 3RS was started after the commissioning of the 3RS on 28 November 2024.

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.

A total of 259 ferry movements between HKIA SkyPier and Macau were audited in the reporting period. All audited movements travelled through the SCZ with average speeds of 15 knots or below, complying with the SkyPier Plan.

The audit of construction and associated vessels has started since August 2016. The 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. The ET conducted checking to ensure the MSS records all deviation cases accurately. A total of 4 skipper training workshops were conducted by the ET during the reporting period with captains of construction vessels associated with 3RS contracts. Another 18 skipper training workshops were held by contractors’ Environmental Officers and competency tests were conducted subsequently with the trained captains by ET.

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 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).