Monthly EM&A Report

EXECUTIVE SUMMARY

This is the 183^rd monthly Environmental Monitoring and Audit (EM&A) report for the Project “Construction of Lamma Power Station Extension” prepared by the Environmental Team (ET). This report presents the results of impact monitoring on air quality and noise for the said project in July 2025.

The reclamation and submarine pipeline works were completed with the first gas-fired combined cycle unit (viz. Unit L9) commissioned in October 2006, working currently on base load operation. To cope with the scheduled retirement of the existing units at Lamma Power Station, the second gas-fired combined cycle unit (viz. Unit L10) L10 was commissioned for reliable operation in February 2020.

In September 2016, the Government approved HK Electric to construct the third combined cycle gas-fired generating unit (Unit L11) to implement the 2020 Fuel Mix Target. L11 was commissioned for reliable operation effective in May 2022.

With the Government’s approval to build the fourth combined cycle gas-fired generating unit (L12) in July 2018, the associated construction work commenced in April 2019. L12 was commissioned for reliable operation effective on 31/3/2024. The operational EM&A work for L9, L10, L11 and L12 is recorded in the separate monthly EM&A report for the Project “Operation of Lamma Power Station Extension”.

With the Government’s approval to build the fifth combined cycle gas-fired generating unit (L13) in November 2023, the associated construction work commenced in end January 2024.

Air and noise monitoring were performed. The results were checked against the established Action/Limit (AL) levels. An on-site audit was conducted once per week. The implementation status of the environmental mitigation measures, Event/Action Plan and environmental complaint handling procedures were also checked.

Construction Activities Undertaken

Construction activities for Lamma Extension during the reporting month are tabulated as follows:

Item	Construction Activities
Unit L13 Civil and Building Works	Civil advance work

Environmental Monitoring Works

All monitoring work at designated stations was performed as scheduled satisfactorily.

Air Quality

No exceedance of Action/Limit levels on 1-hour TSP and 24-hour TSP for air quality was recorded in the month.

Noise

No exceedance of Action and Limit levels for noise arising from the construction of Lamma Extension was recorded in the month.

Site Environmental Audit

Independent Environmental Checker (IEC) conducted a site inspection on 24/7/2025. The site conditions were generally satisfactory.

Site audits were carried out on a weekly basis to monitor environmental issues on the construction site. The site conditions were generally satisfactory.

Environmental Licensing and Permitting

Description	Permit No.	Valid Period		Issued To	Date of Issuance
Description	Permit No.	From	To	Issued To	Date of Issuance
Varied Environmental Permit	EP-071/2000/D	28/09/20	-	HK Electric	28/09/20
Construction Noise Permit	GW-RS0498-25	19/05/25	18/11/25	Contractor	14/05/25
WPCO Discharge Licence	WT100046647-2025	18/07/25	31/07/30	Contractor	18/07/25
Waste Disposal Billing Account	Account No.: 7054247	03/04/25	-	Contractor	03/04/25

Implementation Status of Environmental Mitigation Measures

Environmental mitigation measures for the construction activities as recommended in the EM&A manual were implemented in the reporting month.

Environmental Complaints

No complaint in relation to the environmental impact of the construction activities was received in the reporting month.

Future Key Issues

The future key issues to be considered in the coming month are as follows:

Unit L13 Civil and Building Works

- to continue monitoring the noise level during construction and to ensure compliance with the CNP’s already obtained;

- to monitor and review the sufficiency of the dust suppression measures provided and increase the resources accordingly if necessary;

- to treat wastewater in sedimentation tank for re-use on construction activities and to ensure compliance with the WPCO discharge licence already obtained.

Concluding Remarks

The environmental performance of the project was generally satisfactory.

1. INTRODUCTION

1.1 Background

The Environmental Team (hereinafter called the “ET”) was formed within the Hongkong Electric Co. Ltd (HEC) to undertake Environmental Monitoring and Audit for “Construction of Lamma Power Station Extension” (hereinafter called the “Project”). Under the requirements of Section 6 of Environmental Permit EP-071/2000/D, an EM&A programme for impact environmental monitoring set out in the EM&A Manual (Construction Phase) is required to be implemented. In accordance with the EM&A Manual, environmental monitoring of air quality, noise and water quality and regular environmental audits are required for the Project. With the completion of reclamation and submarine pipeline works, no further marine water quality monitoring would be required.

The Project involves the construction of a gas-fired power station employing combined cycled gas turbine technology, forming an extension to the existing Lamma Power Station. The key elements of the Project including the construction activities associated with the transmission system and submarine gas pipeline are outlined as follows.

· dredging and reclamation to form approximately 22 hectares of usable area;

· construction of six 300MW class gas-fired combined cycle units;

· construction of a gas receiving station;

· construction of a transmission system linking the Lamma Extension to load centres on Hong Kong Island;

· laying of a gas pipeline for the supply of natural gas to the new power station

This report summarizes the environmental monitoring and audit work for the Project for the month of July 2025.

1.2 Project Organisation

An Environmental Management Committee (EMC) has been set up in HEC to oversee the Project. The management structure includes the following:

· Environmental Protection Department (The Authority);

· Environmental Manager (The Chairman of the Environmental Management Committee);

· Engineer;

· Independent Environmental Checker (IEC);

· Environmental Team (ET);

· Contractor.

The project organisation chart for the construction EM&A programme is shown in Appendix A.

1.3 Construction Works undertaken during the Reporting Month

Construction activities for Unit L13 civil and building works were civil advance work. Layout plan for construction site is shown in Figure 1.1.

The main construction activities carried out during the reporting month and the corresponding environmental mitigation measures are summarized in Table 1.1. The implementation of major mitigation measures in the month is provided in Appendix I.

Table 1.1 Construction Activities and Their Corresponding Environmental Mitigation Measures

Item	Construction Activities	Environmental Mitigation Measures
Unit L13 Civil and Building Works
1	Civil Advance Work	Wastewater - All wastewater will be pumped to the sedimentation ponds for desilting process. After that, wastewater will be re-used for construction activities or pumped for storage. - All wastewater will be treated before discharge to fulfill the requirement of wastewater discharge licence. Noise - General noise mitigation measure employed at all work sites throughout the construction phase. - Following all requirement of Construction Noise Permit issued by EPD. - Generators operate with door closed. Waste Management - Waste Management Plan submitted and implemented. - Construction will be store in the proposed storage area for recycled or disposal. Air - Dust suppression in the main haul road. - Using ULSD for PMEs. - Cover dusty stockpile with tarpaulin and water spraying. - Wheel-washing was installed in site - Well maintain and check the PMEs

Item

Construction Activities

Environmental Mitigation Measures

Unit L13 Civil and Building Works

Civil Advance Work

Wastewater

- All wastewater will be pumped to the sedimentation ponds for desilting process. After that, wastewater will be re-used for construction activities or pumped for storage.

- All wastewater will be treated before discharge to fulfill the requirement of wastewater discharge licence.

Noise

- General noise mitigation measure employed at all work sites throughout the construction phase.

- Following all requirement of Construction Noise Permit issued by EPD.

- Generators operate with door closed.

Waste Management

- Waste Management Plan submitted and implemented.

- Construction will be store in the proposed storage area for recycled or disposal.

Air

- Dust suppression in the main haul road.

- Using ULSD for PMEs.

- Cover dusty stockpile with tarpaulin and water spraying.

- Wheel-washing was installed in site

- Well maintain and check the PMEs

1.4 Summary of EM&A Requirements

The detailed EM&A monitoring work for air quality and noise are described in Sections 2 and 3 respectively. Regular environmental site audits for air quality, noise, water quality and waste management were carried out.

The following environmental audits are summarized in Section 4 of this report:

· Environmental monitoring results;

· Waste Management Records;

· Weekly site audit results;

· The status of environmental licensing and permits for the Project;

· The implementation status of environmental protection and pollution control/ mitigation measures.

Future key issues will be reported in Section 5 of this report.

2. AIR QUALITY

2.1 Monitoring Requirements

1-hour and 24-hour TSP monitoring at agreed frequencies were conducted to monitor air quality. The impact monitoring data were checked against the Action/Limit Levels as determined in the Baseline Monitoring Report (Construction Phase). Appendix B shows the established Action/Limit Levels for Air Quality.

2.2 Monitoring Locations

Three dust monitoring locations were selected for 1-hour TSP sampling (AM1, AM2 & AM3) while four monitoring locations were selected for 24-hour TSP sampling (AM1, AM2, AM3 and AM4). Table 2.1 tabulates the monitoring stations. The locations of the monitoring stations are shown in Figure 2.1.

Table 2.1 Air Quality Monitoring Locations

Location I.D.	Description
AM1	Reservoir
AM2	East Gate
AM3	Ash Lagoon
AM4	Tai Yuen Village

2.3 Monitoring Equipment

It is agreed with EPD that continuous 24-hour TSP air quality monitoring would be performed using TEOM continuous dust monitor and the MINIVOL Portable Sampler at AM1,2&3 and AM4 respectively. TEOM continuous dust monitors were used to carry out 1-hour TSP monitoring at AM1, AM2 and AM3. Table 2.2 summarises the equipment used in dust monitoring.

Table 2.2 Air Quality Monitoring Equipment

Equipment	Model and Make
24-hour sampling: Continuous TSP Dust Meter MINIVOL Portable Sampler 1-hour sampling: Continuous TSP Dust Meter	TEOM continuous dust monitor Thermo Scientific AIRMETRICS TEOM continuous dust monitor Thermo Scientific

Equipment

Model and Make

24-hour sampling:

Continuous TSP Dust Meter

MINIVOL Portable Sampler

1-hour sampling:

Continuous TSP Dust Meter

TEOM continuous dust monitor

Thermo Scientific

AIRMETRICS

TEOM continuous dust monitor

Thermo Scientific

2.4 Monitoring Parameters, Frequency and Duration

Table 2.3 summarises the monitoring parameters, duration and frequency of air quality monitoring. The monitoring schedule for the reporting month is shown in Appendix C.

Table 2.3 Air Quality Monitoring Parameter, Duration and Frequency

Monitoring Stations	Parameter	Duration	Frequency
AM1	1-hour TSP	1	3 hourly samples every 6 days
AM1	24-hour TSP	24	Once every 6 days
AM2	1-hour TSP	1	3 hourly samples every 6 days
AM2	24-hour TSP	24	Once every 6 days
AM3	1-hour TSP	1	3 hourly samples every 6 days
AM3	24-hour TSP	24	Once every 6 days
AM4	24-hour TSP	24	Once every 6 days

2.5 Monitoring Procedures and Calibration Details

MINIVOL (24- hour TSP Monitoring):

Preparation of Filter Papers

· Visual inspection of filter papers was carried out to ensure that there were no pinholes, tears and creases;

· The filter papers were then labeled before sampling.

· The filter papers were equilibrated at room temperature and relative humidity < 50% for at least 24 hours before weighing.

Field Monitoring

· During collection of the sampled filter paper, the information on the elapse timer was logged. Site observations around the monitoring stations, which might have affected the monitoring results, were also recorded. Major pollution sources, if any, would be identified and reported.

· The post-sampling filter papers were removed carefully from the filter holder and folded to avoid loss of fibres or dust particles from the filter papers;

· The filter holder and its surrounding were cleaned;

· A pre-weighed blank filter paper for the next sampling was put in place and aligned carefully. The filter holder was then tightened firmly to avoid leakage;

· The programmable timer was set for the next 24 hrs sampling period;

· The post-sampling filter papers were equilibrated at room temperature and relative humidity < 50% for at least 24 hours before weighing.

TEOM continuous dust monitor (24- hour TSP and 1- hour TSP Monitoring):

· The following parameters of the TEOM model dust meters are regularly checked to ensure proper functionality:

o Operation Mode;

o Frequency of the tapered element;

o Main flow;

o Bypass flow.

Maintenance & Calibration

· The monitoring equipment and their accessories are maintained in good working conditions.

· Monitoring equipment is calibrated at monthly intervals. Calibration details are shown in Appendix F.

2.6 Results and Observations

All dust monitoring works were conducted on schedule. All monitoring data and graphical presentation of the monitoring results are provided in Appendix D. Key findings and observations are provided below:

1-hour TSP

No exceedance of 1-hour TSP Action/Limit Level was recorded in the month.

24-hour TSP

No exceedance of 24-hour TSP Action/Limit Level was recorded in the month.

3. NOISE

3.1 Monitoring Requirements

Continuous noise alarm monitoring at Ash Lagoon/Ching Lam were carried out to calculate the noise contributed by the construction activities at the two critical NSR’s, viz. Long Tsai Tsuen/Hung Shing Ye and the school within the village of Tai Wan San Tsuen. The impact monitoring data for construction noise were checked against the limit levels specified in the EM&A Manual. With the availability of the construction noise permits, impact monitoring for the construction work during the restricted hours was also carried out. Section 3 presents the details of the construction noise permits.

The impact noise monitoring data were checked against the limit levels specified in the EM&A Manual. Appendix B shows the established Action/Limit Levels for noise.

3.2 Monitoring Locations

In accordance with the EM&A manual, the identified noise monitoring locations of Ash Lagoon and Ching Lam are shown in Figure 3.1.

3.3 Monitoring Equipment

The sound level meters used for noise monitoring complied with International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1). The noise monitoring equipment used is shown in Table 3.1.

Table 3.1 Noise Monitoring Equipment

Equipment	Model
Sound level meters	B&K 2250
Sound level calibrator	B&K 4231

3.4 Monitoring Parameters, Frequency and Duration

Continuous alarm monitoring was carried out at Ash Lagoon and Ching Lam. The measurement duration and parameter of noise monitoring were presented in Table 3.2 as follows:

Table 3.2 Noise Monitoring Duration and Parameter

Location

Time Period

Frequency

Parameter

Ash Lagoon

Ching Lam

Day-time:

0700-1900 hrs on normal weekdays

Evening-time & holidays:

0700-2300 hrs on holidays; and 1900-2300 hrs on all other days

Night-time:

2300-0700 hrs of next day

Day-time:

30 minutes

Evening-time & holidays:

5 minutes

Night-time:

5 minutes

30-min L_Ae_q

5-min L_Ae_q

3.5 Monitoring Procedures and Calibration Details

Monitoring Procedures

Continuous Noise Monitoring for Lamma Extension Construction

The measured noise levels (MNL's) were collected at the noise alarm monitoring stations at Ash Lagoon and Ching Lam. The notional background noise levels (viz. baseline noise data at Ash Lagoon and Ching Lam) were applied to correct the corresponding MNL's in 30-min/5-min L_Aeq.

A wind speed sensor was installed at Station Building Rooftop. The wind speed signal was used to determine whether the data from Ash Lagoon and Ching Lam noise alarm monitoring stations were affected. The instantaneous data was discarded in case the instantaneous wind speed exceeded 10 m/s. The 30-min/5-min L_Aeq was considered valid only if the amount of valid data was equal to or above 70%.

Equipment Calibration

The sound level meters and calibrators were verified by the manufacturer or accredited laboratory. With the endorsement of the Independent Environmental Checker, the enhancement of calibration of sound level meter at the noise monitoring stations was implemented. The monthly manual on-site calibration using sound level calibrator was replaced by the daily auto charge injection calibration function of the sound level meter. For additional quality assurance, manual on-site calibration would still be conducted for the noise monitoring stations once every 6 months. The manual on-site calibrations for Ash Lagoon and Ching Lam noise monitoring stations were carried out in February 2025 and June 2025. The next calibrations for the two corresponding noise monitoring stations were scheduled in August 2025 and December 2025.

3.6 Results and Observations

Continuous noise monitoring was conducted at the two monitoring stations at Ash Lagoon and Ching Lam.

All monitoring results and their graphical presentations are provided in Appendix E. No exceedance of noise Action/Limit Level was recorded in the month.

4. ENVIRONMENTAL AUDIT

4.1 Review of Environmental Monitoring Procedures

The environmental monitoring procedures were regularly reviewed by the Environmental Team. No modification to the existing monitoring procedures was recommended.

4.2 Assessment of Environmental Monitoring Results

Monitoring results for Air Quality and Noise

The environmental monitoring results for Air Quality and Noise in the reporting month presented in Sections 2 and 3 respectively are summarized in Table 4.1.

Table 4.1 Summary of AL Level Exceedances on Monitoring Parameters

Item	Parameter Monitored	Monitoring Period	No. of Exceedances In			Event/Action Plan Implementation Status and Results
Item	Parameter Monitored	Monitoring Period	Action Level		Limit Level	Event/Action Plan Implementation Status and Results
Air
1	Ambient TSP (24-hour)	01/07/2025- 31/07/2025	0	0
2	Ambient TSP (1-hour)	01/07/2025- 31/07/2025	0	0
Noise
1	Noise level at the critical NSR’s predicted by the noise alarm monitoring system	01/07/2025- 31/07/2025	0		0

4.3 Waste Management

Wastes generated from this Project include inert construction and demolition (C&D) materials and non-inert C&D materials. Inert C&D materials comprise excavated materials and broken concrete. Non-inert C&D materials comprise general refuse, metals and paper/ cardboard packaging, plastics, chemical waste, etc.

Inert C&D material and non-inert C&D material disposed of in July 2025 are shown in Table 4.2.

Table 4.2 Estimated Amounts of Waste in July 2025

Total Inert C&D Waste Materials	Non-inert C&D Materials
Total Inert C&D Waste Materials	C&D Materials Recycled	C&D Waste Disposed of at Landfill	Chemical Waste
0 Tonnes	3.49 Tonnes	0 Tonnes	0 Tonnes

The monthly waste flow tables prepared by the contractors are attached in Appendix K

4.4 Site Environmental Audit

Independent Environmental Checker (IEC) conducted a site inspection on 24/7/2025. The site conditions were generally satisfactory.

Site audits were carried out by ET on a weekly basis to monitor environmental issues at the construction sites to ensure that all mitigation measures were implemented timely and properly. The site audit findings for the reporting month are summarized in Appendix H. The site conditions were generally satisfactory. All required mitigation measures were implemented.

4.5 Status of Environmental Licensing and Permitting

All permits/licenses obtained for the project are summarised in Table 4.3.

Table 4.3 Summary of Environmental Licensing and Permit Status

Description	Permit No.	Valid Period		Highlights	Status
Description	Permit No.	From	To	Highlights	Status
Varied Environmental Permit	EP-071/2000/D	28/09/20	-	The whole construction work site	Valid
Construction Noise Permit	GW-RS0498-25	19/05/25	18/11/25	Civil and building works for Unit L13. Operation of PME during restricted hours.	Valid
WPCO Discharge Licence	WT00046647-2025	18/07/25	31/07/30	Civil and building works for Unit L13.	Valid
Waste Disposal Billing Account	Account No.: 7054247	03/04/25	-	Civil and building works for Unit L13	Valid

4.6 Implementation Status of Environmental Mitigation Measures

Mitigation measures detailed in the permits and the EM&A Manual (Construction Phase) are required to be implemented. An updated summary of the Environmental Mitigation Implementation Schedule (EMIS) is presented in Appendix I.

4.7 Implementation Status of Event/Action Plans

The Event/Action Plans extracted from the EM&A Manual (Construction Phase) are presented in Appendix G.

4.8 Implementation Status of Environmental Complaint Handling Procedures

In July 2025, no complaint in relation to the environmental impact of the construction activities was received.

Table 4.4 Environmental Complaints Received in July 2025

Case Reference /

Date, Time Received /

Date, Time Concerned

Descriptions /

Actions Taken

Conclusion /

Status

Nil

N/A

Table 4.5 Outstanding Environmental Complaints Carried Over