Figure 1.1	Locations of Key Construction Activities
Figure 2.1	Locations of Air and Noise Monitoring Stations and Chek Lap Kok Wind Station
Figure 2.2	Water Quality Monitoring Stations
Figure 2.3	Vessel based Dolphin Monitoring Transects in Construction, Post-Construction, and Operation Phases
Figure 2.4	Land based Dolphin Monitoring Locations in Baseline and Construction Phases
Figure 2.5	Sightings Distribution of Chinese White Dolphins
Figure 2.6	Sighting Locations of Chinese White Dolphins with Different Group Sizes
Figure 2.7	Sighting Locations of Chinese White Dolphins Engaged in Different Behaviours
Figure 2.8	Sighting Locations of Mother-calf Pairs
Figure 2.9	Plots of First Sightings of All CWD Groups from Land-based Stations
Figure 2.10	Location for Passive Acoustic Monitoring

Appendices

Appendix A	Project Organisation Chart
Appendix B	Environmental Mitigation Implementation Schedule (EMIS) for Construction Phase
Appendix C	Monitoring Results

Abbreviations

3RS	Three-Runway System
AAHK	Airport Authority Hong Kong
AECOM	AECOM Asia Company Limited
AFCD	Agriculture, Fisheries and Conservation Department
AIS	Automatic Information System
ANI	Encounter Rate of Number of Dolphins
APM	Automated People Mover
AW	Airport West
BHS	Baggage Handling System
C&D	Construction and Demolition
CAP	Contamination Assessment Plan
CAR	Contamination Assessment Report
CTCC	Construction Traffic Control Centre
CWD	Chinese White Dolphin
DCM	Deep Cement Mixing
DEZ	Dolphin Exclusion Zone
DO	Dissolved Oxygen
EIA	Environmental Impact Assessment
EM&A	Environmental Monitoring & Audit
EMIS	Environmental Mitigation Implementation Schedule
EP	Environmental Permit
EPD	Environmental Protection Department
EPSS	Emergency Power Supply Systems
ET	Environmental Team
FCZ	Fish Culture Zone
HKBCF	Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities
HKIA	Hong Kong International Airport
HSF	High Speed Ferry
IEC	Independent Environmental Checker
LKC	Lung Kwu Chau
MMHK	Mott MacDonald Hong Kong Limited
MMWP	Marine Mammal Watching Plan
MSS	Maritime Surveillance System
MTRMP-CAV	Updated Marine Travel Routes and Management Plan for Construction and Associated Vessel
NEL	Northeast Lantau
NWL	Northwest Lantau
PAM	Passive Acoustic Monitoring
SC	Sha Chau
SCZ	Speed Control Zone
SCLKCMP	Sha Chau and Lung Kwu Chau Marine Park
SS	Suspended Solids
STG	Encounter Rate of Number of Dolphin Sightings
SWL	Southwest Lantau
T2	Terminal 2
The Manual	The Updated EM&A Manual
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
TSP	Total Suspended Particulates
WL	West Lantau
WMP	Waste Management Plan

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 30^th Construction Phase Quarterly EM&A Report for the Project which summarises the monitoring results and audit findings of the EM&A programme during the reporting period from 1 April 2023 to 30 June 2023.

Key Activities in the Reporting Period

The key activities of the Project carried out in the reporting period included reclamation works and land-based works. Works in the reclamation areas included seawall construction, filling, together with runway, taxiways, concourse and associated works. Land-based works on existing airport island involved mainly airfield works, Terminal 2 expansion works, modification and tunnel work for Automated People Mover (APM) and Baggage Handling System (BHS), and preparation work for utilities, with activities include road and drainage works, cable ducting, demolition, piling, and excavation works.

EM&A Activities Conducted in the Reporting Period

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

Monitoring Activities	Number of Sessions
1-hour Total Suspended Particulates (TSP) air quality monitoring	96
Noise monitoring	52
Water quality monitoring	39
Vessel line-transect surveys for Chinese White Dolphin (CWD) monitoring	6
Land-based theodolite tracking survey effort for CWD monitoring	6

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

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

Snapshots of Good Environmental Practices in the Reporting Period


Use of automated water sprinklers with timers for dust suppression	Training was provided to designated operators for regular monitoring on discharge quality and wastewater treatment facility maintenance	Different colour of labels were applied to PMEs being used at different time period during restricted hours

Key examples of good site practices implemented in the Project are highlighted as below:

1. Use of automated water sprinklers with timers for dust suppression.

2. Training was provided to designated operators for regular monitoring on discharge quality and wastewater treatment facility maintenance.

3. Different colour of labels were applied to PMEs being used at different time period during restricted hours.

Summary Findings of the EM&A Programme

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

Monitoring results of construction dust, construction noise, construction waste and CWD monitoring did not trigger the corresponding Action and Limit Levels in the reporting period.

The water quality monitoring results for all parameters, except dissolved oxygen (DO), obtained during the reporting period were within the corresponding Action and Limit Levels stipulated in the EM&A programme. Relevant investigation and follow-up actions will be conducted according to EM&A programme if the corresponding Action and Limit Levels are triggered. For DO, six testing results in June 2023 triggered the relevant Action Level and one testing result triggered the relevant Limit Level, and investigations were conducted accordingly. The investigation findings concluded that the cases were not related to the Project. To conclude, the construction activities during the reporting period did not introduce adverse impact to all water quality sensitive receivers.

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 breach of Limit Level was recorded.	Nil
Breach of Action Level^		√	No breach of Action Level was recorded.	Nil
Complaint received in this reporting period	√		A complaint regarding noise nuisance was received on 9 June 2023.	ET requested the relevant contractor to provide information related to the complaint. The bridge demolition works was carried out on 9 June 2023. No observation regarding noise nuisance was recorded during regular site inspections. The relevant contractor was reminded to review and continuously implement their enhanced noise mitigation measures. Hence, the case was considered closed.
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.

According to Condition 2.6 of EP, AAHK has advanced the preparation works for the designation of the North Lantau Marine Park as recommended in the approved EIA Report. Draft map of the proposed North Lantau Marine Park was gazetted by the Government on 3 March 2023 for 60-day public inspection. The public inspection period ended on 1 May 2023 with no objection received.

1 Introduction

1.1 Background

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

Airport Authority Hong Kong (AAHK) commissioned Mott MacDonald Hong Kong Limited (MMHK) to undertake the role of Environmental Team (ET) for carrying out the Environmental Monitoring & Audit (EM&A) works during the construction phase of the Project in accordance with the Updated EM&A Manual (the Manual) submitted under EP Condition 3.1 [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 ha 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 was presented in Appendix A of the Construction Phase Monthly EM&A Report No. 88.

1.2 Scope of this Report

This is the 30^th Construction Phase Quarterly EM&A Report for the Project which summarises the key findings of the EM&A programme during the reporting period from 1 April 2023 to 30 June 2023.

1.3 Project Organisation

The Project’s organisation structure is provided in Appendix A. Contact details of the key personnel have been updated and provided in Table 1.1.

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 Leaders	Heidi Yu	2828 5704
	Deputy Environmental Team Leaders	Ken Wong	2828 5817
Independent Environmental Checker (IEC) (AECOM Asia Company Limited)	Independent Environmental Checker	Roy Man	3922 9141
	Deputy Independent Environmental Checker	Jackel Law	3922 9376

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 1525

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 1525

Airfield Works:

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

Third Runway Concourse:

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
	Safety Officer	Keith Chau	9620 7515
Contract 3405 Third Runway Concourse Foundation and Substructure Works (China Road and Bridge Corporation – Bachy Soletanche Group Limited – LT Sambo Co., Ltd. Joint Venture)	Project Manager	Francis Choi	9423 3469
	Environmental Officer	Jacky Lai	9028 8975
Contract 3408 Third Runway Concourse and Apron Works (Beijing Urban Construction Group Company Limited and Chevalier (Construction) Company Limited Joint Venture)	Assistant Project Manager	Qian Zhang	5377 7976
	Environmental Officer	Malcolm Leung	7073 7559

Terminal 2 (T2) Expansion:

Party	Position	Name	Telephone
Contract 3508 Terminal 2 Expansion Works (Gammon Engineering & Construction Company Limited)	Project Director	Richard Ellis	6201 5637
Environmental Officer	Fanny Law	6184 4650

Party

Position

Name

Telephone

Contract 3508 Terminal 2 Expansion Works

(Gammon Engineering & Construction Company Limited)

Project Director

Richard Ellis

6201 5637

Environmental Officer

Fanny Law

6184 4650

Automated People Mover (APM) and Baggage Handling System (BHS):

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

Construction Support (Facilities):

Party	Position	Name	Telephone
Contract 3721 Construction Support Infrastructure Works (China State Construction Engineering (Hong Kong) Ltd.)	Site Agent	Thomas Lui	9011 5340
	Environmental Officer	John Mak	6273 8703
Contract 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
	Safety Health Environmental Manager	Mike Leung	6625 2550

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 Director	John Adams	6111 6989
	Environmental Officer	Phoebe Ng	9869 1105
Contract 3804 East and Landside Fire Stations (Beijing Urban Construction Group Company Limited - Beijing Urban Construction International Company Limited - Kin Shing (Leung's) General Contractors Ltd Joint Venture)	Project Manager	Mr. Zhang Xianda	4661 6818
	Environmental Officer	Ms. Kimberly Wong	5542 1669
Contract 3805 New Airport District Police Operational Base (Chinney Construction Co., Ltd.)	Project Manager	Cheuk Wing Wai	9339 8321
	Environmental Officer	Mike Li	6306 8547

Construction Support (Services / Licences):

Party	Position	Name	Telephone
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	Mr. Ian Li	9750 6438
	Environmental Officer	Mr. Tang Kai Fun	9406 3526
Contract 3913 Asphalt Batching Plant (SPR Joint Venture)	Project Manager	Xie Yi Sheng	6580 6005
Contract 3913 Asphalt Batching Plant (SPR Joint Venture)	Environmental Officer	Kenneth Chan	9300 2182

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

The key activities of the Project carried out in the reporting period are located in reclamation areas and existing airport island respectively. Works in the reclamation areas included seawall construction, filling, together with runway, taxiways, concourse and associated works. Land-based works on existing airport island involved mainly airfield works, Terminal 2 expansion works, modification and tunnel work for APM and BHS systems, and preparation work for utilities, with activities include road and drainage works, cable ducting, demolition, piling, and excavation works. The locations of the key construction activities are presented in Figure 1.1.

1.6 Summary of EM&A Programme Requirements

The status for all environmental aspects are presented in Table 1.3. The EM&A requirements remained unchanged during the reporting period.

Table 1.3: Summary of Status for All Environmental Aspects under the Updated EM&A 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 result was 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 result was 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 result was 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.	On-going for reclamation works. General impact water quality monitoring for water jetting works was completed on 23 May 2017.
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 and would be resumed if there are marine-based DCM works in the coming future.
Sewerage and Sewage Treatment
Methodology for carrying out annual sewage flow monitoring for concerned gravity sewer	Methodology to be prepared and submitted to EPD one year before the scheduled commencement of operation of the proposed third runway.	The proposed methodology of the annual sewage flow monitoring was approved by EPD. The annual flow monitoring was started from June 2021 and completed in 2022.
Details of the routine H₂S monitoring system for the sewerage system of 3RS	Details to be prepared and submitted to EPD at least one year before commencement of the operation of 3RS.	The H₂S monitoring proposal was submitted to EPD in April 2023 and accepted by EPD in June 2023.
Waste Management
Waste Monitoring	At least weekly	On-going
Land Contamination
Supplementary Contamination Assessment Plan (CAP)	At least 3 months before commencement of any soil remediation works.	The Supplementary CAP was submitted and approved by EPD under EP condition 2.20.
Contamination Assessment Report (CAR) for Golf Course	CAR to be submitted for golf course	The CAR for Golf Course was submitted and accepted by EPD.
CAR for Terminal 2 Emergency Power Supply System	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 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.
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.	On-going
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 and approved by 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 was reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4.
Impact Monitoring	Weekly	On-going
Establishment Works Monitoring	Bi-monthly	On-going
Long Term Management (10 years) Monitoring	Annually	On-going
Environmental Auditing
Regular site inspection	Weekly	On-going
Marine Mammal Watching Plan (MMWP) implementation measures	Monitor and check	On-going
Dolphin Exclusion Zone (DEZ) Plan implementation measures	Monitor and check	On-going
SkyPier High Speed Ferries (HSF) implementation measures	Monitor and check	On-going
Construction and Associated Vessels implementation measures	Monitor and check	On-going
Silt Curtain Deployment Plan implementation measures	Monitor and check	On-going
Spill Response Plan implementation measures	Monitor and check	On-going
Complaint Hotline and Email Channel	Construction phase	On-going
Environmental Log Book	Construction phase	On-going

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

The EM&A programme also involved weekly site inspections and related auditing conducted by ET for the checking of implementation of required environmental mitigation measures 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 summarised as below:

● Forty-nine environmental management meetings for EM&A review with works contracts.

The EM&A programme has been following 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 B.

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 for reference.

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 Summary of Monitoring Results

The air quality monitoring results in the reporting period are summarised in Table 2.2 and the graphical plot is presented in Appendix C.

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

	AR1A	AR2
Apr 2023	100%	100%
May 2023	100%	100%
Jun 2023	100%	100%
Overall	100%	100%
Note: The percentages are calculated by dividing the number of monitoring results within their corresponding Action and Limit Levels by the total number of monitoring results.

All monitoring results were within their corresponding Action and Limit Levels at all monitoring stations in the reporting period.

General meteorological conditions in the last month of the previous quarter and this reporting period were recorded and summarised in Table 2.3.

Table 2.3: General Meteorological Condition during Impact Air Quality Monitoring

	Weather	Dominant Wind Direction
Mar 2023	Sunny to Cloudy	Northwest to Northeast
Apr 2023	Sunny to Cloudy	Northwest to Southeast
May 2023	Sunny to Cloudy	Northwest to Southeast
Jun 2023	Cloudy to Drizzle	North to Southwest

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 for reference.

Table 2.4: Impact Noise Monitoring Stations

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

2.2.2 Summary of Monitoring Results

The noise monitoring results in the reporting period are summarised in Table 2.5 and the graphical plot is presented in Appendix C.

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

	NM1A	NM4	NM5	NM6
Apr 2023	100%	100%	100%	100%
May 2023	100%	100%	100%	100%
Jun 2023	100%	100%	100%	100%
Overall	100%	100%	100%	100%
Note: The percentages are calculated by dividing the number of monitoring results within their corresponding Action and Limit Levels by the total number of monitoring results.

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

General meteorological conditions in the last month of the previous quarter and this reporting period were recorded and summarised in Table 2.6.

Table 2.6: General Meteorological Condition during Impact Noise Monitoring

	Weather
Mar 2023	Sunny to Cloudy
Apr 2023	Sunny to Cloudy
May 2023	Sunny to Cloudy
Jun 2023	Cloudy to Drizzle

2.2.3 Conclusion

Major sources of noise dominating the monitoring stations observed during the construction noise impact monitoring were traffic noise near NM1A, school activities near 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

During the reporting period, water quality monitoring was conducted three days per week, at mid-flood and mid-ebb tides. Water quality monitoring was undertaken at a total of 14 water quality monitoring stations, comprising 6 impact (IM) stations, 5 sensitive receiver (SR) stations, and 3 control (C) stations in the vicinity of the water quality sensitive receivers around the existing airport island in accordance with the Manual.

The purpose of water quality monitoring at the IM stations is to promptly capture any potential water quality impacts from the Project before the impacts could become apparent at sensitive receivers (represented by the SR stations). Table 2.7 describes the details of the monitoring stations. Figure 2.2 shows the locations of the monitoring stations.

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

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

Notes:

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

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

(3) The monitoring location for SR8 is subject to further changes due to silt curtain arrangements and the progressive relocation of this seawater intake.

(4) With the seawall completion and removal of enhanced open sea silt curtains, these monitoring stations were relocated back to their original locations. For IM2, there was minor adjustment of the monitoring location.

2.3.1 Action and Limit Levels

The Action and Limit Levels for general water quality monitoring stipulated in the EM&A programme for triggering the relevant investigation and follow-up procedures under the programme are presented in Table 2.8. The control and IM stations during flood tide and ebb tide for general water quality monitoring are presented in Table 2.9.

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

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

Notes:

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

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

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

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

Control Station	Impact Stations
Flood Tide
C1	IM1, IM2, IM7, SR3
SR2¹	IM7, IM10, IM11, IM12, SR1A, SR3, SR4A, SR8
Ebb Tide
C1	SR4A
C2	IM1, IM2, IM7, IM10, IM11, IM12, SR1A, SR2, SR3, SR8

Notes:

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

2.3.2 Summary of Monitoring Results

The summary or results within their corresponding Action and Limit Levels in the reporting period are presented in Table 2.10. The weather and sea conditions in the last month of the previous quarter and this reporting period were recorded and summarised in Table 2.11.

Table 2.10: Percentage of Water Quality Monitoring Results within Action and Limit Levels

	General Water Quality Monitoring
	DO (Surface and Middle)	DO (Bottom)	SS	Turbidity
Apr 2023	100% (221/221)	100% (221/221)	100% (273/273)	100% (221/221)
May 2023	100% (221/221)	100% (221/221)	100% (273/273)	100% (221/221)
Jun 2023	100% (221/221)	96.8% (214/221)	100% (273/273)	100% (221/221)
Overall	100%	98.9%	100%	100%

General Water Quality Monitoring

(Surface and Middle)

(Bottom)

Turbidity

Apr 2023

100%

(221/221)

100%

(221/221)

100%

(273/273)

100%

(221/221)

May 2023

100%

(221/221)

100%

(221/221)

100%

(273/273)

100%

(221/221)

Jun 2023

100%

(221/221)

96.8%

(214/221)

100%

(273/273)

100%

(221/221)

Overall

100%

98.9%

100%

Notes:

(1) The percentages are calculated by dividing the number of depth-averaged results complying with their corresponding Action and Limit Levels by the total number of depth-averaged results.

(2) The number in the bracket under the percentage represents the total number of depth-averaged results complying with their corresponding Action and Limit Levels over the total number of depth-averaged results.

Table 2.11: General Weather Condition and Sea Condition during Impact Water Quality Monitoring

	Weather	Sea Condition
Mar 2023	Sunny to Rainy	Calm to Rough
Apr 2023	Fine to Rainy	Calm to Rough
May 2023	Sunny to Rainy	Calm to Rough
Jun 2023	Sunny to Rainy	Calm to Rough

The monitoring results for all parameters, except dissolved oxygen (DO), obtained during the reporting period were within their corresponding Action and Limit Levels stipulated in the EM&A programme. The detailed monitoring results are presented in Appendix C. Relevant investigation and follow-up actions will be conducted according to the EM&A programme if the corresponding Action and Limit Levels are triggered.

For DO, six testing results triggered the Action Level and one testing result triggered the Limit Level during the reporting period, and investigations were conducted accordingly. Summaries of results triggering Action and Limit Levels for DO are presented in Table 2.12 and Table 2.13.

Details of the investigation findings were presented in Construction Phase Monthly EM&A Report No. 90, which concluded that results triggering the Action and Limit Levels were not related to the Project.

Table 2.12: Summary of DO (Bottom) Compliance Status (Mid-Ebb Tide)

	IM1	IM2	IM7	IM10	IM11	IM12	SR2	SR3	SR4A
29/06/2023	D	D							D
No. of result triggering Action or Limit Level	1	1	0	0	0	0	0	0	1

Table 2.13: Summary of DO (Bottom) Compliance Status (Mid-Flood Tide)

	IM1	IM2	IM7	IM10	IM11	IM12	SR3	SR4A
29/06/2023							D
No. of result triggering Action or Limit Level	1	1	0	0	0	0	1	1

Note: The monitoring results compiled with their corresponding Action or Limit Levels are presented in Appendix C.

Legend:
	Result within corresponding Action and Limit Levels
	Result triggered the Action Level at monitoring station located upstream of the Project based on dominant tidal flow
D	Result triggered the Action Level at monitoring station located downstream of the Project based on dominant tidal flow
	Result triggered the Limit Level at monitoring station located upstream of the Project based on dominant tidal flow
D	Result triggered the Limit Level at monitoring station located downstream of the Project based on dominant tidal flow
	Upstream station with respect to the Project during the respective tide based on dominant tidal flow
	Downstream station with respect to the Project during the respective tide based on dominant tidal flow

2.3.3 Conclusion

During the reporting period, it is noted that most of the monitoring results were within their corresponding Action and Limit Levels while six testing results and one testing result triggered the corresponding Action and Limit Levels of DO respectively. Investigations were conducted accordingly. Based on the findings presented in Construction Phase Monthly EM&A Report No. 90, the cases that triggered the corresponding Action and Limit Levels were not related to the Project. Hence, the Project did not introduce adverse impact to all water quality sensitive receivers. All required actions under the Event and Action Plan were followed.

Nevertheless, the non-project related triggers were attended to and initiated corresponding action and measures. As part of the EM&A programme, the construction methods and mitigation measures for water quality will continue to be monitored and opportunities for further enhancement will continue to be explored and implemented where possible, to strive for better protection of water quality and the marine environment.

In the meantime, the contractors were reminded to implement and maintain all mitigation measures during weekly site inspections and regular environmental management meetings. These include maintaining mitigation measures properly for reclamation works including filling, seawall construction and ground improvement works as recommended in the Manual.

2.4 Waste Monitoring

In accordance with the Manual, waste generated from construction activities was audited once per week to determine if wastes were 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 assessed during the audits.

2.4.1 Action and Limit Levels

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

Table 2.14: Action and Limit Levels for Construction Waste

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

2.4.2 Summary of Monitoring Results

Weekly monitoring of the Project construction works was carried out by the ET in the reporting period to check and monitor the implementation of proper waste management practices.

Recommendations made by the ET included provision and maintenance of proper chemical waste storage area, as well as handling, segregation, and regular disposal of general refuse. The contractors had taken actions to implement the recommended measures. Waste management audits were carried out by ET according to the requirements of the Waste Management Plan, updated EM&A Manual and the implementation schedule of the waste management mitigation measures in Appendix B.

Based on updated contractors’ information, summary of construction waste generated in the reporting period is presented in Table 2.15. ET and IEC carried out site audits regularly and reviewed the trip ticket system.

The contractors established the recycling strategy for C&D materials with proper planning and design to maximize recycling and reuse. Dedicated recyclers were employed for different kinds of recyclable materials by the contractors. Dedicated areas for sorting of materials are established on site. Recyclable materials such as steel bar, metal strip, aluminium, paper and plastic are sorted on-site and transported off-site for recycling during this reporting period.

Table 2.15: Construction Waste Statistics

	C&D⁽¹⁾ Material Stockpiled for Reuse or Recycle (m³)	C&D Material Reused in the Project (m³)	C&D Material Reused in other Projects (m³)	C&D Material Transferred to Public Fill⁽²⁾ (m³)	Chemical Waste (kg)	Chemical Waste (l)	General Refuse (tonne)
Apr 2023⁽³⁾	2,037	2,494	605	10,665	0	0	2,781
May 2023⁽³⁾	124	10,772	795	10,613	0	0	3,006
Jun 2023	45	8,839	4,462	4,750	0	0	3,216
Total	2,206	22,105	5,862	26,028	0	0	9,003
Notes: 1. C&D refers to Construction and Demolition. 2. C&D materials not suitable for reuse on-site, including asphalt waste and sediment slurry, were transferred to public fill during the reporting period. 3. Updated figures were provided by contractors.

There were 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 is managed according to the EIA Report, Updated EM&A Manual and Waste Management Plan 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. 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 Waste Management Plan and Further Development Proposal.

Backfilling works for marine sediment generated from the reclaimed land area were conducted during the reporting period. The details of the marine sediment sampling, treatment and backfilling can be referred to Annual EM&A Report No.7.

2.5 Chinese White Dolphin Monitoring

CWD monitoring was conducted by vessel line transect survey at a frequency of two full surveys per month, supplemented by land-based theodolite tracking survey and PAM. The frequency of the land-based theodolite tracking survey during the construction phase was one day per month at both Sha Chau (SC) and Lung Kwu Chau (LKC) stations, as stipulated in the Manual. The vessel survey transects followed the transect lines proposed in the Manual and are consistent with those used in the Agriculture, Fisheries and Conservation Department (AFCD) long-term CWD monitoring programme. The transect locations of CWD monitoring by vessel line transect survey are shown in Figure 2.3, whilst the land-based theodolite tracking survey stations are described in Table 2.16 and depicted in Figure 2.4. The location of the PAM device is shown in Figure 2.10.

Table 2.16: Land-based Theodolite Tracking Survey Station Details

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

Stations

Location

Geographical Coordinates

Station Height (m)

Approximate Tracking Distance (km)

Sha Chau (SC)

22° 20’ 43.5” N

113° 53’ 24.66” E

45.66

Lung Kwu Chau (LKC)

22° 22’ 44.83” N

113° 53’ 0.2” E

70.40

2.5.1 Action and Limit Levels

The Action Level and Limit Level for CWD monitoring were formulated by an action response approach using the running quarterly dolphin encounter rates (STG and ANI) derived from baseline monitoring data, as presented in the CWD Baseline Monitoring Report. The derived values of Action and Limit Levels for CWD monitoring are shown in Table 2.17.

Table 2.17: Derived Values of Action Level and Limit Level for Chinese White Dolphin Monitoring

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

2.5.2 Summary of Monitoring Results

2.5.2.1 Vessel Line Transect Survey

Survey Effort

During the reporting period from April to June 2023, a total of six sets of vessel line transect survey covering all transects in Northeast Lantau (NEL), Northwest Lantau (NWL), Airport West (AW), West Lantau (WL) and Southwest Lantau (SWL) survey areas were conducted at a frequency of twice per month, in each survey area.

A total of around 1,342 km of survey effort was collected from these surveys, with around 96.1% of the total survey effort being conducted under favourable weather condition (i.e. Beaufort Sea State 3 or below with favourable visibility). Details of the survey effort data are presented in Appendix C.

CWD Sighting

From April to June 2023, there were a total of 41 sightings of CWD, with 146 dolphins sighted (Table 2.18). Amongst these sightings, 40 with 144 dolphins were recorded during on-effort searches under favourable weather condition.

When breaking down the sightings by survey areas, one sighting of a single dolphin, 34 sightings with a total of 132 dolphins and six sightings with a total of 13 dolphins were recorded in NWL, WL and SWL respectively during the current reporting period. No CWD was sighted in NEL survey area.

Compared with the previous quarter (i.e. January to March 2023), both the total number of CWD sightings and total number of the dolphins slightly decreased by 5% and 12% respectively. These results were attributed by a notable reduction of the dolphin sightings and the number of dolphins in NWL survey area in the current reporting quarter.

Compared with the same quarter of last year (i.e. April to June 2022), there were slight decreases in both the total number of sightings and the total number of dolphins by 9% and 12% respectively. There was significant increase in term of both number of sightings and number of dolphins in WL by 36% and 59% respectively. On the other hand, there were notable decreases in both number of sightings and number of dolphins in SWL by 63% and 83% respectively.

Table 2.18 below shows the comparison of the numbers of sightings and dolphins amongst the current reporting period, last quarter, and the same quarter of last year.

Table 2.18: Summary of Number of CWD Sightings and Number of Dolphins for the Same Quarter Last Year, Previous Quarter, and Current Reporting Period

	Same Quarter of Last Year	Previous Reporting Period	Current Reporting Period
	April to June 2022	January to March 2023	April to June 2023
NEL	0 (0)	0 (0)	0 (0)
NWL	4 (8)	13 (52)	1 (1)
AW	0 (0)	2 (4)	0 (0)
WL	25 (83)	23 (99)	34 (132)
SWL	16 (75)	5 (11)	6 (13)
Total	45 (166)	43 (166)	41 (146)

Note: Values in ( ) represent number of dolphins

The distribution of CWD sightings recorded from April to June 2023 is illustrated in Figure 2.5. In NWL survey area, the only CWD sighting was recorded at southwestern tip of Lung Kwu Chau. In WL, CWD sightings were clustered at the waters between Tai O and Fan Lau. In SWL, CWD sightings were mostly recorded around Fan Lau and Fan Lau Tung Wan. No CWD sightings were recorded in NEL survey area during the reporting period. Details of the sighting data are presented in Appendix C.

Figure 2.5: Sightings Distribution of Chinese White Dolphins from April to June 2023

Remarks: (1) Please note that there are 41 pink circles on the map indicating the sighting locations of CWD. Some of them were very close to each other and therefore appear overlapped on this sighting distribution map. (2) Marine park excludes land area and the landward boundary generally follows the high water mark along the coastline.

Encounter Rate

The dolphin encounter rates for the number of on-effort dolphin sightings per 100 km survey effort (STG) and for the total on-effort number of dolphins per 100 km survey effort (ANI) in the whole survey area (i.e. NEL, NWL, AW, WL and SWL) for April, May and June 2023 are summarised in Table 2.19.

In this reporting period, the monthly STG increased from April to June 2023 (STG: from 1.93 to 4.42). The monthly ANI decreased from April to May followed by a strong rebound in June 2023 (ANI: from 11.10 to 9.20 and rebounded to 13.25). For running quarterly encounter rates, both running quarterly STG and ANI decreased from April to June 2023. No Action Level for CWD monitoring was triggered during the reporting period.

Compared with the previous reporting period (i.e. January to March 2023), overall both the running quarterly STG and ANI decreased from Mar 2022 to Jun 2023 (STG: from 3.30 to 3.10; ANI from 12.73 to 11.16). While comparing with the same quarter of last year (i.e. April to June 2022), both the running quarterly STGs and ANIs were lower. Encounter rates for these periods are summarised in Table 2.19 and graphical presentation is provided in Appendix C.

Table 2.19: Summary of Monthly and Running Quarterly STG and ANI of Chinese White Dolphin for the Same Quarter Last Year, Previous Quarter, and Current Reporting Period

	Same Quarter of Last Year			Previous Reporting Period			Current Reporting Period
	Apr 22	May 22	Jun 22	Jan 23	Feb 23	Mar 23	Apr 23	May 23	Jun 23
Monthly STG	2.00	4.83	3.80	1.56	4.60	3.80	1.93	2.92	4.42
Monthly ANI	4.89	18.36	16.16	4.24	16.56	17.81	11.10	9.20	13.25
Running Quarterly STG	1.93	2.93	3.50	1.92	2.55	3.30	3.46	2.89	3.10
Running Quarterly ANI	7.02	11.19	12.93	4.83	8.52	12.73	15.19	12.65	11.16

Note: For detailed calculations of encounter rates STG and ANI for the current reporting period, please refer to the Construction Phase Monthly EM&A Report Nos. 88, 89, and 90.

Group Size

Between April and June 2023, the group size of CWD sightings ranged from one to 10 dolphins. The average group size of CWD was 3.56 dolphins per group, which is slightly lower than that of the last quarter (3.86 dolphins per group). The average group size of CWD in this reporting quarter is slightly smaller than that of the same quarter of last year (3.69 dolphins per group for April to June 2022).

In this reporting quarter, the number of CWD sightings with medium group size (i.e. 3-9 dolphins) was dominant. There was one CWD sighting with large group size (i.e. 10 or more dolphins) recorded in WL in this reporting period.

There was no apparent difference in the distribution of small-sized dolphin groups and medium-sized dolphin groups in all survey areas. Sighting locations of CWD groups with different group sizes are depicted in Figure 2.6.

Figure 2.6: Sighting Locations of Chinese White Dolphins with Different Group Sizes

Remarks: (1) Please note that there are 41 circles on the map indicating the sighting locations of CWD. Some of them were very close to each other and therefore appear overlapped on this sighting distribution map. (2) Marine park excludes land area and the landward boundary generally follows the high water mark along the coastline.

Activities and Association with Fishing Boats

From April to June 2023, 12 sightings of CWD were recorded with foraging activities. Amongst them, five sightings were observed associated with operating purse seiners. Three of these five sightings were recorded in WL while the other two observation were made in SWL.

Sightings with foraging activities recorded in the current reporting period was lower than that in the previous reporting period (i.e. 16 sightings involved foraging activities between January and March 2023). The number of CWD sightings with foraging activities in this reporting period was similar to that in the same quarter of last year (i.e. 13 sightings between April and June 2023).

The sighting locations of CWDs engaged in different behaviours during the current reporting period are illustrated in Figure 2.7.

Figure 2.7: Sighting Locations of Chinese White Dolphins Engaged in Different Behaviours

Remarks: Marine park excludes land area and the landward boundary generally follows the high water mark along the coastline.

Mother-calf Pairs

From April to June 2023, nine sightings of CWD were recorded with the presence of mother-and-unspotted juvenile pairs, which was the same as that recorded in the previous reporting quarter (i.e. January to March 2023). The number of CWD sightings with the presence of mother-calf pairs was similar to that recorded in the same quarter of last year (i.e. 10 sightings between April and June 2022).

These nine sightings with the presence of mother-calf pairs recorded during the current reporting period were all recorded in WL survey area. The locations of CWD sightings with the presence of mother-calf pairs are shown in Figure 2.8.

Figure 2.8: Sighting Locations of Mother-calf Pairs

Remarks: (1) Please note that there are nine circles on the map indicating the sighting locations of Mother-Calf pairs. (2) Marine park excludes land area and the landward boundary generally follows the high water mark along the coastline.

Photo Identification

Between April and June 2023, a total number of 49 different CWD individuals were identified altogether for 90 times. Re-sighting information of CWD individuals provides an initial idea of their range use and apparent connection between different areas of Lantau waters. Amongst these 49 different CWD individuals, 22 animals (i.e. NLMM020, SLMM003, SLMM007, SLMM010, SLMM025, SLMM027, SLMM037, SLMM044, SLMM049, SLMM052, SLMM073, WLMM007, WLMM043, WLMM056, WLMM063, WLMM071, WLMM073, WLMM079, WLMM086, WLMM114, WLMM147 and WLMM159) were sighted for more than once.

Five individuals including SLMM003, SLMM010, SLMM037, WLMM007 and WLMM114 were re-sighted in different survey areas during this reporting period. The most frequently re-sighted individuals in this reporting quarter were SLMM027 and WLMM079 that both were successfully identified for five times each. Both the number of CWD individuals re-sighted more than once and the number of CWD individuals showing cross-area movement were much lower than those of the last reporting period from January to March 2023.

A summary of photo identification works is presented in Table 2.20. Representative photos of the 49 identified individuals and figures depicting the sighting locations of the aforementioned five individuals re-sighted in different survey areas in this reporting period are presented in Appendix C.

Table 2.20: Summary of Photo Identification

Individual ID	Date of sighting	Sighting Group No.	Area	Individual ID	Date of sighting	Sighting Group No.	Area
NLMM001	09-Jun-23	2	WL	WLMM001	04-May-23	3	WL
NLMM013	13-Jun-23	1	NWL	WLMM007	04-May-23	2	WL
NLMM020	13-Apr-23	1	WL		01-Jun-23	2	SWL
		2	WL	WLMM018	04-May-23	2	WL
	09-Jun-23	5	WL	WLMM030	02-Jun-23	8	WL
NLMM021	13-Apr-23	1	WL	WLMM043	13-Apr-23	1	WL
NLMM027	13-Apr-23	1	WL		02-Jun-23	8	WL
NLMM040	02-Jun-23	3	WL	WLMM056	13-Apr-23	1	WL
NLMM063	02-Jun-23	8	WL			2	WL
SLMM003	13-Apr-23	5	WL		04-May-23	1	WL
	18-Apr-23	2	WL	WLMM062	02-Jun-23	1	WL
	23-May-23	4	WL	WLMM063	13-Apr-23	4	WL
	01-Jun-23	2	SWL		18-Apr-23	1	WL
SLMM007	13-Apr-23	5	WL	WLMM065	04-May-23	6	WL
	18-Apr-23	1	WL	WLMM067	13-Apr-23	4	WL
	02-Jun-23	8	WL	WLMM071	02-Jun-23	6	WL
SLMM010	18-Apr-23	3	WL		09-Jun-23	1	WL
	01-Jun-23	2	SWL	WLMM073	04-May-23	6	WL
	09-Jun-23	5	WL		23-May-23	1	WL
SLMM014	18-Apr-23	3	WL			4	WL
SLMM023	04-May-23	4	WL	WLMM077	02-Jun-23	3	WL
SLMM025	23-May-23	1	WL	WLMM079	13-Apr-23	5	WL
		4	WL		18-Apr-23	1	WL
SLMM027	04-May-23	2	WL