Revision History

CONTENTS

Executive Summary............................................................................................................................................................ 1

1. Basic Contract Information............................................................................................................................... 3
2. Water Quality.......................................................................................................................................................... 8
3. Waste....................................................................................................................................................................... 12
4. Landfill Gas Monitoring................................................................................................................................... 13
5. Landscape.............................................................................................................................................................. 16
6. Ecology (Coral Monitoring)........................................................................................................................... 17
7. Ecology (Fishery Monitoring)....................................................................................................................... 19
8. Summary of Exceedance, Complaints, Notification of Summons and Prosecutions.............. 21
9. EM&A Site Inspection....................................................................................................................................... 23
10. Future Key Issues............................................................................................................................................... 24
11. Conclusions and Recommendations.......................................................................................................... 25

Appendix A                           Overview of Desalination Plant in Tseung Kwan O

Appendix B                          Summary of Implementation Status of Environmental Mitigation
Appendix C                          Impact Monitoring Schedule

Appendix D                          Event/Action Plan

Appendix E                          Landfill Gas Equipment Calibration Certificate (Not Used)

Appendix F                          Landfill Gas Monitoring Data (Not Used)

Appendix G                           Waste Flow Table

Appendix H                          Ecology Survey Report (Not Used)

Appendix I                            Site Inspection Proforma

Appendix J                            Complaint Log

Executive Summary

Introduction

A1. The Project, Design, Build and Operate First Stage of Tseung Kwan O Desalination Plant (TKODP), is a Designated Project under the Environmental Impact Assessment Ordinance (Cap. 499) (EIAO) and is currently governed by a Further Environmental Permit (EP No. FEP – 01/503/2015/B) for the operation phase of the Contract.

A2. In accordance with the Environmental Monitoring and Audit (EM&A) Manual for the Contract, EM&A works for marine water quality, waste management and ecology should be carried out by Environmental Team (ET), Aurecon Hong Kong Limited (Aurecon), during the Tseung Kwan O Desalination Plant.

A3. The TKODP commenced the operation stage on 1 July 2024. This is the 18th Operation Phase Monthly EM&A Report, prepared by Aurecon, for the Contract summarizing the monitoring results and audit findings of the EM&A programme at and around Tseung Kwan O Area 137 (TKO 137) during operation of Tseung Kwan O Desalination Plant in December 2025.

A4. The EM&A programme for this contract has covered environmental monitoring on water quality and Contractor's environmental performance auditing in the aspects of dust, landfill gas, water quality, waste management, Landscape and Visual and Ecology.

Summary of exceedance & investigation & follow-up

WATER QUALITY MONITORING

A5. The first-year operation phase marine water quality monitoring was completed on 30 June 2025. No marine water quality monitoring was conducted during the reporting period.

A6.  According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th year, continuous monitoring of effluent quality was discontinued and replaced with effluent water monitoring in compliance with discharge license requirements starting from 15 August 2025.

Ecology Impact Monitoring

A7.      No Coral monitoring was conducted during the reporting period.

A8.  According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th year, coral monitoring will be conducted on a quarterly basis starting from August 2025.

A9. Operation phase fishery monitoring for wet season 2025 was carried out on 16 and 23 August 2025. Details of the survey report were included in the October Monthly Report.

Landfill Gas Monitoring

A10. In this reporting period, no landfill gas monitoring was conducted.

A11. According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th year, landfill gas monitoring will be conducted on a six-month basis starting from August 2025.

Weekly Site Inspections

A12. In this reporting period, bi-weekly site inspections were carried out by ET on 11 and 22 December 2025. Joint site inspections of the operation work by ET and IEC were carried out on 22 December 2025 to audit the mitigation measures implementation status.

A13. According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th year, site inspection will be conducted on a bi-weekly basis starting from 15 August 2025.

Complaint Handling and Prosecution

A14. No environmental complaints, notification of summons and prosecution were received in the reporting period.

Reporting Change

A15. According to the contractor's information, the Anti-scalant dosage commenced on 10 April 2025. The Anti-scalant water quality test was also conducted starting from the same date.

A16. The works of TKODP were substantially completed on 30 June 2024 and the plant commenced the operation phase on 1 July 2024. A Justification of Termination of the EM&A Programme for the Construction Phase was resubmitted to the EPD on 11 August 2025 and approved by the EPD on 15 August 2025.

A proposal to change the operation phase EM&A programme was submitted to the EPD on 11 August 2025 and approved by the EPD on 15 August 2025.

Basic Contract Information

Background

1.1. The Acciona Agua, S.A. Trading, Jardine Engineering Corporation, Limited and China State Construction Engineering (Hong Kong) Limited as AJC Joint Venture (AJCJV) is contracted to carry out the Design, Build and Operate First Stage of Tseung Kwan O Desalination Plant (TKODP) under Contract No. 13/WSD/17 (the Contract).

1.2. Aurecon Hong Kong Limited (Aurecon) is commissioned by AJCJV to undertake the Environmental Team (ET) services as required and/or implied, both explicitly and implicitly, in the Environmental Permit (EP), Environmental Impact Assessment Report (EIA Report) (Register No. AEIAR-192/2015) and Environmental Monitoring and Audit Manual (EM&A Manual) for the Contract; and to carry out the Environmental Monitoring and Audit (EM&A) programme in fulfillment of the EIA Report's EM&A requirements and Contract No. 13/WSD/17 Specification requirements.

1.3. Pursuant to the Environmental Impact Assessment Ordinance (EIAO), the Director of Environmental Protection granted the Environmental Permit (No. EP-01/503/2015/B) to Water Supplies Department (WSD); and granted the Further Environmental Permit (No. FEP-01/503/2015/B) to AJCJV for the Contract.

The Reporting Scope

1.4. This is the 18th Operation Phase Monthly EM&A Report for the Contract which summarizes the key findings of the EM&A programme of the Tseung Kwan O Desalination Plant Operation phase during the reporting period from 1 December to 31 December 2025.

Contract Organization

1.5. The Contract Organization structure for Operation Phase is presented in Figure 1.1.

Figure 1.1            Contract Organization Chart

1.6. Contact details of the key personnel are presented in Table 1.1 below:

Table 1.1             Contact Details of Key Personnel

1.7 Summary of Operation Works

1.7. Details of the major operation activities undertaken in this reporting period are shown below.

1.8. As informed by the Contractor, key activities carried out in this reporting period for the Contract included the followings:

• Potable Water Production

1.9. The key environmental mitigation measures implemented for the Contract in this reporting period associated with the above operation works include:

• Regularly monitoring of the effluent
• Sorting and storage of general refuse and operation waste

1.10. Summary of the valid permits, licences, and/or notifications on environmental protection for this Contract is presented in Table 1.2.

Table 1.2           Summary of the Status of Valid Environmental Licence, Notification, Permit and Documentations

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

Table 1.3           Summary of Status for Key Environmental Aspects under the EM&A Manual

1.12. Other than the EM&A work by ET, environmental briefings, trainings, and regular environmental management meetings were conducted, in order to enhance environmental awareness and closely monitor the environmental performance of the contractors.

1.13. The EM&A programme has been implemented in accordance with the recommendations presented in the approved EIA Report and the EM&A Manual. A summary of implementation status of the environmental mitigation measures for the operation phase of the Contract during the reporting period is provided in Appendix B.

Water Quality

2.1. In accordance with the recommendations of the EIA, water quality monitoring is required during operation phase. The following Section provides details of the water quality monitoring to be undertaken by the Environmental Team (ET) to verify the distance of sediment and brine plume dispersion and to identify whether the potential exists for any indirect impacts to occur to ecological sensitive receivers.

2.2. The first-year operation phase marine water quality monitoring was completed on 30 June 2025. No marine water quality monitoring was conducted during the reporting period.

2.3. According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th years, continuous monitoring of effluent quality was discontinued and replaced with effluent water monitoring in compliance with discharge license requirements starting from 15 August 2025.

WATER DISCHARGE LICENSE (WT00044188-2023 PART 1)

2.4. In accordance with the WT00044188-2023 Part 1, the sampling should be followed the specified frequency, and the parameters of the sample should not be exceeded the limit stated as the water discharge license. Details derived limit levels for water quality are presented in Table 2.1.

Table 2.1           Derived Limit Levels for Water Quality

*Remark:

1. Anti-scalant water quality testing will only be conducted whenever anti-scalant dosage is adopted.

Monitoring Location

2.5. In accordance with the discharge license, the Monitoring shall be sampling at Brine Outfall Shaft.

Monitoring Results and Observations

2.6. According to the contractor's information, the Anti-scalant dosage commenced on 10 April 2025. The Anti-scalant water quality test was also conducted starting from the same date.

2.7. The weekly In-situ monitoring was carried out on 4, 11, 18 and 25 November 2025 and the monthly laboratory measurement was carried out on 3 November 2025.

2.8. No exceedance of the results was obtained during the reporting period. The detail results are summarized in Table 2.2, 2.3 and 2.4.

Table 2.2            Summary of In-situ Results for Discharge License (Weekly)

Table 2.3            Summary of Lab Results for Discharge License (Monthly)

Remark:

1. As confirmed by various laboratories in Hong Kong, the lowest detection limit for Sodium Metabisulphite is <2 mg/L. Due to the limitation of the laboratory, the lowest result for Sodium Metabisulphite will only be shown as < 2 mg/L.
2. As discussed and agreed with EPD on 12 December 2024, since the lowest detection limit of anti-scalant chemical(s) (ACUMER 4035) in Hong Kong is 5 mg/L due to the limitation of laboratory, the lowest measurement result of anti-scalant chemical(s) (ACUMER 4035) will only be shown as < 5mg/L.

Table 2.4            Summary of Daily Flow Rate of Reporting Period

3. Waste

3.1. The waste generated from this Contract includes inert construction and demolition (C&D) materials, and non-inert C&D materials. Non-inert C&D materials are made up of general refuse, vegetative wastes and recyclable wastes such as plastics and paper/cardboard packaging waste. Steel materials generated from the Contract are also grouped into non-inert C&D materials as the materials were not disposed of with other inert C&D materials. With reference to relevant handling records and trip tickets of this Contract, the quantities of different types of waste generated in the reporting month are summarized in Table 3.1. Details of cumulative waste management data are presented as a waste flow table in Appendix G.

Table 3.1           Quantities of Waste Generated from the Contract during the reporting period

Notes: (1) Plastics refer to plastic bottles / containers, plastic sheets / foam from packaging material

3.2. No dewater sludge was generated by the operation in the reporting period.

4. Landfill Gas Monitoring

MONITORING REQUIREMENT

4.1. In accordance with Section 11 of the EM&A Manual, monthly monitoring of landfill gas is required for the first year of operation at buildings within the Project Site and consultation zone. Part of the desalination plant and the indicative area of natural slope mitigation works fall within the SENT Landfill Extension Consultation Zone; and part of the 1,200 mm diameter freshwater mains along Wan Po Road falls within the SENT Landfill and SENT Landfill Extension Consultation Zones, TKO Stage II/III Restored Landfill and TKO Stage I Restored Landfill Consultation Zones.

4.2. Routine monitoring is required at buildings within the Project Site and consultation zones. The monitoring frequency will be monthly for the first year of operation.

4.3. For the manholes and utility pits within the Project Site and along the fresh water mains, each manhole/ utility pit should be monitored with two measurements (at mid depth and base). Each measurement should be monitored for a minimum of 10 minutes. A steady reading and peak reading should be recorded at each manhole/ utility pit and for each measurement.

4.4. Monitoring oxygen, methane, carbon dioxide and barometric pressure would be performed monthly during the operation phase.

MONITORING LOCATION

4.5. The area required to be monitored for landfill gas in the reporting period is shown in Figure 4.1, Figure 4.2 and Figure 4.3.

Overview of Landfill Gas Monitoring Locations

Figure 4.1 Overview of the SENT Extension Consultation Zone and the Contract Site Area

Figure 4.2 Landfill Gas Monitoring Location For Building

Figure 4.3 Landfill Gas Monitoring Location For Manholes/Pits

MONITORING PARAMETERS

4.6. The landfill gas monitoring parameters and the action and limit level are summarized in Table 4.1.

Table 4.1           Action and Limit Level for Landfill Gas Monitoring Equipment

MONITORING EQUIPMENT

4.7. Landfill Gas monitoring was carried out using intrinsically-safe, portable multi-gas monitoring instruments. The gas monitoring equipment is:

• Complying with the Landfill Gas Hazard Assessment Guidance Note as intrinsically safe;
• Capable of continuous barometric pressure and gas pressure measurements;
• Normally operated in diffusion mode unless required for spot sampling, when it should be capable of operating by means of an aspirator or pump;
• Having low battery, fault and over range indication incorporated;
• Capable of storing monitoring data, and shall be capable of being downloaded directly;
• Measure in the following ranges:

• alarm (both audibly and visually) in the event that the concentrations of the following are exceeded:

MONITORING RESULTS AND OBSERVATIONS

4.8. According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th year, landfill gas monitoring will be conducted on a six-month basis starting from August 2025.

4.9. In this reporting period, no landfill gas monitoring was conducted during the reporting period.

5. Landscape

MONITORING REQUIREMENTS

5.1. In accordance with Section 8.1 of the EM&A Manual, weekly site audit shall be carried out by the ET including checking whether good site practices are being properly implemented by the Contractor and the extent of the works area within the Clear Water Bay Country Park should be checked by the ET during the weekly site audit.

SITE INSPECTION

5.2. Bi-Weekly site audit was carried out by the ET in the reporting month; all plants were observed to be in satisfactory condition in the reporting month.

5.3. If non-compliance were found during the operation phase, the actions in accordance with the Event and Action Plan will be carried out according to Appendix D.

6. Ecology (Coral Monitoring)

6.1. Under the approval conditions of the EIA Report for the Project, an EM&A programme on coral for the operation phase of the Project is recommended. Pursuant to these EIA approval conditions and Condition 3.1 of the EP and FEP, details of the regular coral monitoring programme have been proposed based on the baseline coral monitoring results in the Report on operation Baseline Coral Monitoring and Regular Coral Monitoring Methodology.

MONITORING LOCATION

6.2. In accordance with Appendix B Section 5.1 of the approved supplementary EM&A Manual, two indirect impact sites (C2 and C3) and one control site (C8) as shown in Figure 6.1 should be monitored during the operation Phase. Operation coral survey should be conducted at the indirect impact and control sites. Ten selected hard coral colonies with similar species should be tagged at each of the control and indirect impact sites before commencement of the operation phase. Tagged hard coral colonies should be monitored in open waters during the operation phase.

Figure 6.1 Spot Dive Check Areas Two Proposed Indirect Impact Sites (C2 and C3) and one control site (C8) during Operation Phase

ACTION AND LIMIT LEVELS

6.3. The Action and Limit Levels have been set based on the derivation criteria specified in the EM&A Manual. The Action/Limit Levels have been derived and are presented in Table 6.1.

Table 6.1           Action and Limit Level for Coral Monitoring Equipment

Note: If the defined Action Level or Limit Level for coral monitoring is exceeded, the actions as set out in

Appendix D, Table D3 will be implemented.

6.4. If non-compliance were found during the opertaion works, the actions in accordance with the Event and Action Plan will be carried out according to Appendix D.

MONITORING FREQUENCY

6.5. Operation phase coral monitoring shall be monitored once per month as the requirement of the first year of operational phase.

MONITORING RESULT AND OBSERVATION

6.6. No coral monitoring was conducted during the reporting period.

6.7. According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th year, coral monitoring will be conducted on a quarterly basis starting from August 2025.

7. Ecology (Fishery Monitoring)

7.1. The purpose of the operation phase regular fisheries monitoring programme is to monitor the potential impacts on fisheries resources in the vicinity of the project site. Apart from the regular fisheries monitoring programme, a water quality monitoring programme in addition to the water quality monitoring programme in the approved EM&A Manual is also described in Section 2.4 to (i) provide supplementary information in the interpretation of the findings of the fisheries monitoring and (ii) assist the monitoring of the potential impact on the Tung Lung Chau Fish Culture Zone (FCZ) in Joss House Bay.

MONITORING LOCATION

7.2. In accordance with Section 2.3 of the approved Methodology Paper on Regular Fisheries Monitoring, it is recommended to set up six (6) fisheries monitoring locations in Joss House Bay and its vicinity to monitor the fisheries resources.

7.3. Two (2) sampling locations are set up in close proximity of the direct footprint of the proposed submarine utilities around TKO Area 137. These sampling locations represent the potential Project impact zones (i.e. areas at and in close proximity to the footprint of the proposed submarine utilities that will be directly affected by the Project works).

7.4. Two (2) gradient locations are proposed between the proposed submarine utilities and Tung Lung Chau FCZ to assist in the interpretation and identification of any potential fisheries impact in the vicinity of the FCZ.

7.5. Two (2) reference locations are proposed in the outer Joss House Bay between the waters of Tung Lung Chau and Fat Tong Mun. These reference locations are further away and will not be affected by the Project discharge (based on the EIA prediction) and will serve as control stations. Any significant fisheries impact identified at the reference locations should be caused by other natural factors or non-Project activities. The trends of fisheries conditions recorded in the reference locations will be used to assist in the interpretation of the trends of fisheries impact identified in the impact and gradient locations.

7.6. The coordinates of the proposed monitoring locations are shown in Figure 7.1.

Figure 7.1 Monitoring Location of Regular Fishery Monitoring during Operation Phase

MONITORING FREQUENCY

7.7. Operation phase fishery monitoring shall be carried out 2 times in wet season (April to October) and 2 times in dry season (December to March) to examine the following:

• Fish species composition;
• Abundance: number of fish captured;
• Diversity of fish resources: species diversity and evenness;
• Size: range of total length; Biomass in weight; and
• Values of catches of commercial species: catch per unit effort (CPUE) and yield per unit effort (YPUE).

MONITORING RESULT AND OBSERVATION

7.8. Operation phase fishery monitoring for wet season 2025 was carried out on 16 and 23 August 2025. Details of the survey report were included in the October Monthly Report.

8. Summary of Exceedance, Complaints, Notification of Summons and Prosecutions

8.1. The Environmental Complaint Handling Procedure is shown in below Figure 9.1:

Figure 9.1            Environmental Complaint Handling Procedures

8.2. The first-year operation phase marine water quality monitoring was completed on 30 June 2025. No marine water quality monitoring was conducted during the reporting period.

8.3. Effluent Quality was conducted sampling point in the reporting month. No exceedance of the results was obtained during the reporting period.

8.4. No coral monitoring was conducted during the reporting period.

8.5. Operation phase fishery monitoring for wet season 2025 was carried out on 16 and 23 August 2025. Details of the survey report were included in the October Monthly Report.

8.6. No landfill gas monitoring was conducted during the reporting period.

8.7. No environmental complaint, notification of summons and prosecution Statistics on complaint and notification of summons and prosecution are summarized in Appendix J.

9. EM&A Site Inspection

9.1. According to the approved proposal to change the operation phase EM&A programme for the 2nd to 10th years, site inspection will be conducted on a bi-weekly basis starting from 15 August 2025.

9.2. Site inspections were carried out to monitor the implementation of proper environmental pollution control and mitigation measures under the Contract. In the reporting period, site inspections were carried out on 11, and 22 December 2025 at the site portions listed in Table 9.1 below.

Table 9.1           Summaries of Site Inspection Record

9.3. Joint site inspections with IEC were carried out on 22 December 2025.

9.4. No Environmental deficiencies were observed during site inspection. The site inspections during the reporting period are summarized in Table 9.2.

Table 9.2           Site Observations

9.5. According to the EIA Study Report, Environmental Permit, contract documents and EM&A Manual, the mitigation measures detailed in the documents should be implemented as much as practical during the reporting period. An updated Implementation Status of Environmental Mitigation Measures (EMIS) is provided in Appendix B. Site inspection proforma of the reporting period is provided in Appendix I.

10. Future Key Issues

10.1. Works to be undertaken in the next reporting month are:

• Potable Water Production

10.2. The major environmental impacts brought by the above operation works include:

• Effluent of the water production work and system cleaning works;
• Waste generation from the operation activities

10.3. The key environmental mitigation measures implemented for the Contract in this reporting period associated with the above operation works include:

• Regularly monitoring of the effluent
• Sorting and storage of general refuse and operation waste

11. Conclusions and Recommendations

11.1. This is the 18^th Monthly EM&A Report for the Project which summarizes the key findings of the EM&A programme during the reporting period from 1 December to 31 December 2025, in accordance with the EM&A Manual and the requirement under FEP-01/503/2015/B.

11.2. The first-year operation phase marine water quality monitoring was completed on 30 June 2025. No marine water quality monitoring was conducted during the reporting period.

11.3. Effluent Quality was conducted sampling point in the reporting month. No exceedance of the results was obtained during the reporting period.

11.4. No coral monitoring was conducted during the reporting period.

11.5. Operation phase fishery monitoring for wet season 2025 was carried out on 16 and 23 August 2025. Details of the survey report were included in the October Monthly Report.

11.6. No landfill gas monitoring was conducted during the reporting period.

11.7. Environmental site inspections were conducted during the reporting period. Observations and reminders were reported during the site inspections. All items are rectified within the reporting period. The environmental performance of the project was therefore considered satisfactory.

11.8. No environmental complaints, notification of summons and prosecution was received in the reporting period.

11.9. The ET will keep track on the operation works to confirm compliance of environmental requirements and the proper implementation of all necessary mitigation measures.

Appendix A

Overview of Desalination Plant in Tseung Kwan O

Appendix B

Summary of Implementation Status of Environmental Mitigation

Note: D – Design stage C – Construction O – Operation

Appendix C

Impact Monitoring Schedule

Contract No. 13/WSD/17

Design, Build and Operate First Stage of Tseung Kwan O Desalination Plant

2^nd Year Operation Monitoring Programme

Remark:

• A proposal to change the operation phase EM&A programme was submitted to the EPD on 11 August 2025 and approved by the EPD on 15 August 2025.
• In accordance with the discharge license, in-situ effluent quality monitoring will be conducted on a weekly basis and laboratory measurement will be conducted on a monthly basis.
• Landfill gas monitoring will be conducted on a six-month basis.
• Coral monitoring will be conducted on a quarterly basis.
• Fishery monitoring will be conducted two times in wet season and two times in dry season in an annal basis.

Appendix D

Event / Action Plan

Table D2             Event and Action Plan for Ecology during Operation Phase

Table D3             Event and Action Plan for Operation Phase Coral Monitoring

Table D4             Event and Action Plan for Operation Phase LFG Hazard

Appendix E

Landfill Gas Equipment Calibration Certification

(Not Used)

Appendix F

Landfill Gas Monitoring Data

(Not Used)

Appendix H

Ecology Survey Report

(Not Used)

Appendix G Waste Flow Table

Name of Department: WSD                                                            Contract No.:  13/WSD/17

Monthly Summary Waste Flow Table for 2025 (year)

Notes:                            

  (1) The performance targets are given in Section 1.69 of Specification B

The waste flow table shall also include C&D materials that are specified in the Contract to be imported for use at the Site.

Plastics refer to plastic bottles/containers, plastic sheets/ foam from packaging material

Appendix I

Site Inspection Proforma

Appendix K Complaint Log

Statistical Summary of Environmental Complaints

Statistical Summary of Environmental Summons

Statistical Summary of Environmental Prosecution