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Contents

List of Tables

Table 1.1 Summary of Environmental Permits under the Project and the Respective Active Works Contracts 3

Table 1.2 Contact Information of Key Personnel 4

Table 1.3 Major CONSRUCTION WORKS IN THE REPORTING PERIOD 5

Table 1.4 Summary of Status for the Environmental Aspects under the EM&A Manual 6

Table 2.1 Action and Limit Levels for Air Quality (Dust) 9

Table 2.2 Air Quality Monitoring Details 9

Table 2.3 Summary of 1-Hour RSP Monitoring Results in the Reporting Period 10

Table 2.4 Summary of 24-hour rolling average RSP Monitoring Results in the Reporting Period 10

Table 2.5 Summary of 24-hour rolling average FSP Monitoring Results in the Reporting Period 11

Table 2.6 Action and Limit Levels for Construction noise 11

Table 2.7 Noise Monitoring Details 12

Table 2.8 Summary of Construction Noise Monitoring Results in the Reporting Period 12

Table 2.9 Calculated Action and Limit Levels for Water Quality 13

Table 2.10 Locations of Impact Water Quality Monitoring Stations and Monitoring Requirements 14

Table 2.11 Water Quality Monitoring Equipment 15

Table 2.12 Key Observations Identified during the site inspection in this Reporting Month 16

Table 2.13 Quantities of Waste Generated in Reporting Period 18

Table 3.1 Major Construction Works in the Next Three MOnths 20

List of Figures

FIGURE 1.1 Location of Project

FIGURE 2.1 Locations of Air Quality Monitoring Stations

FIGURE 2.2 Locations of Noise Montioring Stations

FIGURE 2.3 Locations of Water Quality Monitoring Stations

Executive Summary

This is the Monthly Environmental Monitoring and Audit (EM&A) Report presenting the EM&A works during the period of September 2025 for the San Tin Technopole Phase 1 Development (the Project) in accordance with the EM&A Manual.

Two (2) works contracts, Package 1 Contract 1 (ND/2024/09) and Package 2 Contract 1 (ND/2024/10), are active in this reporting month:

· The construction of ND/2024/09 commenced on 29 September 2025; and

· The construction of ND/2024/10 commenced on 18 September 2025.

A summary of EM&A activities conducted in the reporting period is listed below:

Air Quality Monitoring Continuous impact monitoring

Noise Monitoring

• ND/2024/09 1 session

• ND/2024/10 3 sessions

Water Quality Monitoring

• ND/2024/09 1 session

• ND/2024/10 4 sessions

Environmental Site Inspection

• ND/2024/09 1 session

• ND/2024/10 2 sessions

Environmental site audits, including weekly site inspections of construction works by representatives from ET, Engineer and Contractor; and joint site inspection with Independent Environmental Checker (IEC) were conducted during the reporting period. Based on the audit results and the observation for the reporting period, environmental pollution control and mitigation measures for the Project were properly implemented.

Breaches of Action and Limit Levels for Air Quality

No exceedance of Action and Limit Levels was recorded for impact air quality monitoring in the reporting period.

Breaches of Action and Limit Levels for Noise

No exceedance of Action and Limit Levels was recorded for impact noise monitoring in the reporting period.

Breaches of Action and Limit Levels for Water Quality

No exceedance of Action and Limit Levels was recorded for impact water quality monitoring in the reporting period.

Environmental Complaints, Non-compliance & Summons

There was no environmental complaint, notification of summons or prosecution recorded in the reporting period.

Reporting Change

There was no reporting change in the reporting period.

Key Issues For The Next Three Months

Potential environmental impacts arising from the upcoming construction activities in the next three months are mainly associated with dust emission, noise from plant operation, handling and storage of C&D materials generated from construction activities, efficiency of wastewater and drainage management and tree protection. The ET will keep track on the construction works to confirm compliance with environmental requirements and the proper implementation of all necessary mitigation measures.

1. Introduction

1.1 Background

San Tin Technopole Phase 1 Development (“the Project”) mainly covers innovation & technology (I&T) land parcels to the north of San Tin Highway/Fanling Highway, some residential land to the south and the key infrastructure areas with road connections. The construction of the Project will be delivered under various works contracts and its scope of works comprises the following elements:

• Site formation of land for innovation and technology development, housing, community, commercial and other developments;

• Engineering infrastructure works including but not limited to roadworks, drainage, sewerage, waterworks, pumping stations, fresh water and flushing water service reservoirs, Common Utility Tunnel (CUT) and other associated buildings / structures / E&M systems for the Project; and

• Landscaping works;

The Environmental Impact Assessment (EIA) Report for the San Tin/Lok Ma Chau Development Node (STLMC DN) (Register No. AEIAR-261/2024)was approved on 17 May 2024. Two (2) works contracts, ND/2024/09 and ND/2024/10, are active in this reporting month. The construction of ND/2024/09 commenced on 29 September 2025, and the construction of ND/2024/10 commenced on 18 September 2025. The location of the Project, including the associated works areas of each active works contract is shown in Figure 1.1. The relevant Environmental Permits (EPs) under the Project and the respective works contracts are summarized in Table 1.1.

Table 1.1 Summary of Environmental Permits under the Project and the Respective Active Works Contracts

EP	Designated Project	Work Contracts
EP	Designated Project	ND/2024/09	ND/2024/10
EP-640/2024	San Tin / Lok Ma Chau Water Reclamation Plant	P
EP-641/2024	San Tin / Lok Ma Chau Effluent Polishing Plant	P
EP-664/2025	Revitalisation of San Tin Eastern Main Drainage Channel
EP-665/2025	Recreational Development (“Open Space”) along San Tin Western Main Drainage Channel and at Mai Po Lung Village within Deep Bay Buffer Zone 2
EP-666/2025	New Primary Distributor Road (Road P1) and District Distributor Roads (Roads D1, D2, D3, D4, D5 and D6) for San Tin / Lok Ma Chau Development Node

ERM-Hong Kong, Limited (ERM) is commissioned to undertake the role of Environmental Team (ET) for the Project in accordance with the requirements specified in the Environmental Permit(s), the Environmental Monitoring and Audit (EM&A) Manual, the EIA Report of the STLMC DN project and other relevant statutory requirements.

1.2 Scope of the EM&A Report

This is the Monthly EM&A Report for the Project which summarises the key findings of the EM&A programme during the reporting period of September 2025.

1.3 Organisation Structure

The organisation structure of the Project is shown in Annex A. The key personnel contact names and details are summarised in Table 1.2 below.

Table 1.2 Contact Information of Key Personnel

Party	Position	Name	Telephone
Environmental Team (ET) (ERM-Hong Kong, Limited)	ET Leader	Terence Fong	2271 3156
	ET Leader Representative (EP-640/2024)	Harris Wong	2271 3182
	ET Leader Representative (EP-641/2024)	Harmony Chuh	2271 3273
Independent Environmental Checker (IEC) (Mott MacDonald Hong Kong Limited)	IEC	Thomas Chan	2828 5967
	IEC Representative (EP-640/2024)	Sunny Chan	2828 5962
	IEC Representative (EP-641/2024)	Jay Chua	2828 5710
Contract No. ND/2024/09
Civil Engineering and Development Department	Senior Engineer	Vicky W.K. Yuen	3426 2590
Civil Engineering and Development Department	Engineer	Stanley C.Y. Hung	3152 3564
Engineer’s Representative (ER) (AECOM - Halcrow Joint Venture)	Chief Resident Engineer	Albert Yu	8493 0329
	Senior Resident Engineer	Timonthy Chan	8494 6981
	Senior Resident Engineer	Tony Chan	8491 4870
Contractor (CR15G - Tung Lee Joint Venture)	Construction Manager	K. K. Yuen	9498 1213
	Senior Site Agent	Wilson Chan	9656 8865
	Site Agent	Jason Tse	9371 3184
	Sub Agent	Paul So	5989 0614
	Environmental Officer	Frank Liu	6900 3526
	Environmental Supervisor	Johnny Kam	6178 4786
Contract No. ND/2024/10
Civil Engineering and Development Department	Senior Engineer	Albert S. Lam	3547 1635
Civil Engineering and Development Department	Engineer	Patrick P.L. Wan	3152 3472
Engineer’s Representative (ER) (Arup - Binnies Joint Venture)	Senior Resident Engineer	Raymond Cheung	2908 4924
Contractor (Kuly Construction & Engineering Company Limited)	Senior Project Manager	Ma Kin Man	9552 1734
	Site Agenet	Tang Wing Kai	9300 7037
	Environmental Officer	Brenda Yiu	9346 3966

1.4 Summary of Construction Works

As informed by the Contractor, details of the major construction works carried out in this reporting period are listed in Table 1.3. The construction programme is shown in Annex B.

Table 1.3 Major CONSRUCTION WORKS IN THE REPORTING PERIOD

Construction Works Undertaken	Key Issues	Key Mitigation Measures
Contract No. ND/2024/09
• Topographic Survey • Ground Investigation Work • Wetland Enhancement Works • Soldier Pile Wall Construction • Tree Felling • Demolition Works • Site Formation Works	• Dust emission • Handling and storage of C&D materials • Noise from use of PME • Emission of dark smoke from PMEs • Proper discharge of wastewater • Prevention and proper discharge of surface runoff • Tree protection	• Good site practices • Regular water spraying on stockpiles • Provide tarpaulin sheets coverage on stockpiles and reuse of C&D materials as far as practicable • Use of QPME and noise barrier/acoustic mat/enclosure • Regular maintenance of PMEs • Implementation of wastewater and drainage management • Retain and protect all existing trees and vegetation within the study area which are not directly affected by the works
Contract No. ND/2024/10
• Ground Investigation Work • Preparation Work for Box Culvert • Tree Felling	• Dust emission • Handling and storage of C&D materials • Noise from use of PME • Emission of dark smoke from PMEs • Proper discharge of wastewater • Prevention and proper discharge of surface runoff • Tree protection	• Good site practices • Regular water spraying on stockpiles • Provide tarpaulin sheets coverage on stockpiles and reuse of C&D materials as far as practicable • Use of QPME and noise barrier/acoustic mat/enclosure • Regular maintenance of PMEs • Implementation of wastewater and drainage management • Retain and protect all existing trees and vegetation within the study area which are not directly affected by the works

Construction Works Undertaken

Key Issues

Key Mitigation Measures

Contract No. ND/2024/09

• Topographic Survey

• Ground Investigation Work

• Wetland Enhancement Works

• Soldier Pile Wall Construction

• Tree Felling

• Demolition Works

• Site Formation Works

• Dust emission

• Handling and storage of C&D materials

• Noise from use of PME

• Emission of dark smoke from PMEs

• Proper discharge of wastewater

• Prevention and proper discharge of surface runoff

• Tree protection

• Good site practices

• Regular water spraying on stockpiles

• Provide tarpaulin sheets coverage on stockpiles and reuse of C&D materials as far as practicable

• Use of QPME and noise barrier/acoustic mat/enclosure

• Regular maintenance of PMEs

• Implementation of wastewater and drainage

management

• Retain and protect all existing trees and vegetation within the study area which are not directly affected by the works

Contract No. ND/2024/10

• Ground Investigation Work

• Preparation Work for Box Culvert

• Tree Felling

• Dust emission

• Handling and storage of C&D materials

• Noise from use of PME

• Emission of dark smoke from PMEs

• Proper discharge of wastewater

• Prevention and proper discharge of surface runoff

• Tree protection

• Good site practices

• Regular water spraying on stockpiles

• Provide tarpaulin sheets coverage on stockpiles and reuse of C&D materials as far as practicable

• Use of QPME and noise barrier/acoustic mat/enclosure

• Regular maintenance of PMEs

• Implementation of wastewater and drainage

management

• Retain and protect all existing trees and vegetation within the study area which are not directly affected by the works

1.5 Summary of EM&A Programme Requirements

The status for all environmental aspects is presented in Table 1.4. The EM&A programme requirements remained unchanged during the reporting period.

Table 1.4 Summary of Status for the Environmental Aspects under the EM&A Manual

Parameters	Status
Air Quality
Impact Monitoring	On-going for Contract Nos. ND/2024/09 and ND/2024/10, monitoring conducted continuously
Noise
Baseline Monitoring	The results of baseline noise monitoring for Contract Nos. ND/2024/09 and ND/2024/10 were reported in Baseline Monitoring Report and submitted to EPD under the EM&A Manual Section 16.3
Impact Monitoring	On-going for Contract Nos. ND/2024/09 and ND/2024/10, monitoring conducted once per week
Water Quality
Baseline Monitoring	The results of baseline water quality monitoring for Contract Nos. ND/2024/09 and ND/2024/10 were reported in Baseline Monitoring Report and submitted to EPD under the EM&A Manual Section 16.3
Impact Monitoring	On-going for Contract Nos. ND/2024/09 and ND/2024/10, monitoring conducted 3 days per week
Waste Management
Waste Monitoring	On-going
Land Contamination
Contamination Assessment Plan (CAP), Remediation Action Plan (RAP) and Remediation Report (RR)	On-going
Ecology
Wetland Compensation Monitoring	To be conducted when construction activities occur within 400m from the contiguous pond / wetland habitats on the northern portion of the Project area.
Night Roost Monitoring	Pre-construction Night Roost Survey commenced in September 2025 and on-going at the original roosting sites until commencement of tree felling works. Upon the completion of re-provision of roosting substratum, night roost monitoring to be conducted monthly during dry season at the re-provision site.
Egretry Monitoring	To be conducted monthly during breeding season (between March and early September).
Flight Corridor Monitoring	To be conducted when construction activities occur within this flight corridor.
Woodland Compensation Monitoring	To be conducted after completion of compensatory planting.
Post-transplantation / Post-seedling Planting Monitoring of Flora Species of Conservation Importance	To be conducted after the transplantation / seedling planting.
Post-translocation Monitoring of Fauna Species of Conservation Importance	To be conducted after the translocation.
Pre-construction Site Check and Nest Control	To be conducted in breeding season (March to July). The associated nest control measures to be conducted in non-breeding season (August to February) after pre-construction survey.
Pre-construction Site Check for Eurasian Otter	To be conducted prior to the commencement of construction activities.
Wildlife Corridor Monitoring	To be conducted upon establishment of the wildlife corridors.
Site Environmental Audit
Regular Site Inspection	On-going
Environmental Log Book	On-going

Taking into account the construction works, impact monitoring of air quality, noise, water quality and waste management were carried out in the reporting period. The monitoring schedule of noise and water quality are provided in Annex E2 and Annex F2 respectively.

The EM&A programme also involved environmental site inspections and related auditing conducted by the ET for checking the implementation of the required environmental mitigation measures recommended in the approved EIA Report and relevant EP submissions. The relevant EP submissions are listed in Annex J.

1.6 Status of other Statutory Environmental Requirement

The environmental licenses and permits, including EP, discharge license under Water Pollution Control Ordinance, registration as chemical waste producer, construction noise permit and specified processes license, which were valid in the reporting period are presented in Annex C. No non-compliance with environmental statutory requirements was recorded.

2. Monitoring Results

2.1 Air Quality Monitoring

2.1.1 Monitoring Requirements and Equipment

According to the EM&A Manual of the Project, impact air quality monitoring in terms of 1-hour average Respirable Suspended Particulate (RSP), 24-hour rolling average RSP and 24-hour rolling average Fine Suspended Particulate (FSP) concentrations, was conducted continuously with air sensors. The results of these monitoring parameters are compared with the corresponding Action and Limit levels listed in Table 2.1.

Table 2.1 Action and Limit Levels for Air Quality (Dust)

Parameter	Action Level	Limit Level
1-hour RSP	150 μg/m³	Not applicable
24-hour RSP (rolling average)	Not applicable	100 μg/m³
24-hour FSP (rolling average)	Not applicable	50 μg/m³

The monitoring locations and air sensors used in the continuous impact air quality monitoring are summarised in Table 2.2 and illustrated in Figure 2.1. Copies of the calibration certificates for the onsite air sensors at the monitoring stations and the transfer standards are presented in Annex D1 and Annex D2 respectively.

Table 2.2 Air Quality Monitoring Details

Monitoring Station	Location	Equipment
Monitoring Station	Location	Equipment
M03	Pun Uk Tsuen	MAS-Dust (S/N: dev9204Z250700007)
M04	Chau Tau Tsuen	MAS-Dust (S/N: dev9204Z250700006)
M06	Mai Po San Tsuen	MAS-Dust (S/N: dev9204Z250800014)
M09	Wing Ping Tsuen	MAS-Dust (S/N: dev9204Z250700005)
M11	Shek Wui Wai	MAS-Dust (S/N: dev9204Z250800013)
M13	Rolling Hills (rooftop area)	MAS-Dust (S/N: dev9204Z250800016)
M14	Rolling Hills (outside of Rolling Hills)	MAS-Dust (S/N: dev9204Z250800015)
M15a^(a)	The STEP	Air sensor to be installed

Note(s):

(a) Permission is not granted by Scenic Heights for the installation of sensor at M15 – Scenic Heights. Alternative location M15a – The STEP is proposed, however, is pending the permission from The STEP for the installation during the reporting period.

(b) The relevant monitoring stations for each works contract are listed below:

· ND/2024/09: M06, M11, M13, M14, M15a

· ND/2024/10: M03, M04, M09

(c) As the construction commencements of ND/2024/09 and ND/202410 were on 18 September 2025 and 29 September 2025 respectively, the relevant impact air quality monitoring at the relevant stations was commenced accordingly on the construction commencement dates (i.e. M03, M04 and M09: 18 September 2025, whereas M06, M11, M13 and M14: 29 September 2025).

2.1.2 Results and Observations

The monitoring data and the graphical presentation for 1-hour RSP, 24-hour rolling average RSP and 24-hour rolling average FSP concentrations are summarised in Table 2.3 to Table 2.5. Due to the hoisting of signal No. 8 and above of super typhoon Ragasa from 23 to 24 September 2025, the continuous impact air quality monitoring from 23 September 2025 10:00 am to 25 September 2025 12:00 pm was suspended. The monitoring data and the graphical presentation are provided in Annex D3. Wind data during the reporting period extracted from the Hong Kong Observatory (HKO)’s weather station at Wetland Park are presented in Annex D4.

Table 2.3 Summary of 1-Hour RSP Monitoring Results in the Reporting Period

Monitoring Station	Average (µg/m³)	Range (µg/m³)	Action Level (µg/m³)	Limit Level (µg/m³)
M03	11.9	4.3 - 28.3	150	Not applicable
M04	19.4	6.4 - 35.4	150	Not applicable
M06	27.9	18.2 - 41.7	150	Not applicable
M09	15.8	6.2 - 38.2	150	Not applicable
M11	24.8	13.3 - 49.7	150	Not applicable
M13	20.9	13.5 - 31.2	150	Not applicable
M14	18.9	10.9 - 27.2	150	Not applicable

Table 2.4 Summary of 24-hour rolling average RSP Monitoring Results in the Reporting Period

Monitoring Station	Average (µg/m³)	Range (µg/m³)	Action Level (µg/m³)	Limit Level (µg/m³)
M03	11.1	6.5 - 18.7	Not applicable	100
M04	19.1	12.1 - 27.6	Not applicable	100
M06	27.2	25.2 - 28.4	Not applicable	100
M09	15.3	10.9 - 23.6	Not applicable	100
M11	24.1	18.0 - 31.5	Not applicable	100
M13	20.2	17.1 - 24.8	Not applicable	100
M14	18.7	16.1 - 21.7	Not applicable	100

Table 2.5 Summary of 24-hour rolling average FSP Monitoring Results in the Reporting Period

Monitoring Station	Average (µg/m³)	Range (µg/m³)	Action Level (µg/m³)	Limit Level (µg/m³)
M03	6.8	3.8 - 10.1	Not applicable	50
M04	9.6	5.7 - 13.8	Not applicable	50
M06	9.9	9.4 - 10.6	Not applicable	50
M09	7.7	5.0 - 11.3	Not applicable	50
M11	8.6	7.6 - 10.7	Not applicable	50
M13	8.7	8.0 - 9.7	Not applicable	50
M14	8.1	7.4 - 9.2	Not applicable	50

Major dust sources in the reporting period included haul road traffic and earth moving construction activities associated with the site formation works and tree felling works.

No exceedance of Action and Limit Levels was recorded for construction air quality monitoring in the reporting period. No action was thus required to be undertaken in accordance with the Event and Action Plan presented in Annex D5.

2.2 Noise Monitoring

2.2.1 Monitoring Requirements and Equipment

According to the EM&A Manual of the Project, noise impact monitoring was conducted once per week during the construction phase of the Project. The Action and Limit Levels for construction noise of the Project are provided in Table 2.6 below.

Table 2.6 Action and Limit Levels for Construction noise

Time Period	Action Level	Limit Level
0700 - 1900 hours on normal weekdays	When one documented complaint is received	75 dB(A)^(a),(b)

Note:

(a) If works are to be carried out during restricted hours, the conditions stipulated in the Construction Noise Permit (CNP) issued by the Noise Control Authority have to be followed.

(b) 70 dB(A) and 65 dB(A) for schools during normal teaching periods and school examination periods, respectively.

Noise monitoring was performed using sound level meter at the designated monitoring stations provided in Table 2.7 and Figure 2.2, in accordance with the requirements stipulated in the EM&A Manual. Acoustic calibrator was deployed to check the sound level meters at a known sound pressure level. Details of the deployed equipment are provided in Table 2.7. Copies of the calibration certificates for the equipment are presented in Annex E1.

Table 2.7 Noise Monitoring Details

Monitoring Station ^(a)	Location	Parameter	Frequency	Monitoring Dates	Equipment	Type of Measurement
Monitoring Station ^(a)	Location			Monitoring Dates	Equipment
CM1	69 Mai Po San Tsuen	30-minute measurement between 0700 and 1900 on normal weekdays (Monday to Saturday)	Once per week for 30 mins during the construction period of the relevant works contracts of the Project	30 Sep 2025	Sound Level Meter: Rion NL-52 (S/N: 00331806) Acoustic Calibrator: Larson Davis CAL200 (S/N: 11333)	Free field
CM3	Scenic Heights Block B2					Free field
CM4	30 Rolling Hills Phase II					Façade
CM9	285B Wing Ping Tsuen			18, 22, and 29 Sep 2025	Sound Level Meter: Rion NL-52 (S/N: 00542913) Acoustic Calibrator: Larson Davis CAL200 (S/N: 11333)	Free field
CM10	291 Chau Tau Tsuen					Free field
CM11	218 Chau Tau Tsuen					Free field

Note(s):

(a) The relevant monitoring stations for each works contract are listed below:

- ND/2024/09: CM1, CM3, CM4

- ND/2024/10: CM9, CM10, CM11

2.2.2 Monitoring Schedule for the Reporting Month

The schedule for noise monitoring during the reporting period is provided in Annex E2.

2.2.3 Results and Observations

Results for noise monitoring are summarised in Table 2.8. The monitoring data and the graphical presentation are provided in Annex E3.

Table 2.8 Summary of Construction Noise Monitoring Results in the Reporting Period

Monitoring Station	Average, dB(A), L_eq_{(30 min)}	Range, dB(A), L_eq_{(30 min)}	Limit Level, dB(A), L_eq_{(30 min)}
CM1^(a)	68.3	-	75
CM3^(a)	53.1	-	75
CM4	43.2	-	75
CM9^(a)	64.0	62.9 – 64.6	75
CM10^(a)	58.7	58.1 – 59.2	75
CM11^(a)	53.6	51.0 – 54.9	75

Note(s):

(a) A correction of +3 dB(A) was made to the free field measurements.

Major noise sources during the noise monitoring included noise from use of Powered Mechanical Equipment (PME) due to pile wall construction, tree felling, demolition and site formation works.

No exceedance of Action and Limit Levels was recorded for construction noise monitoring in the reporting period. No action was thus required to be undertaken in accordance with the Event and Action Plan presented in Annex E4.

2.3 Water Quality Monitoring

2.3.1 Monitoring Requirements and Equipment

Water quality impact monitoring was carried out to ensure that any deterioration of water quality was detected, and that timely action was taken to rectify the situation if the deterioration of water quality is caused by the Project. Impact water quality monitoring was undertaken three days per week during the reporting period in accordance with the EM&A Manual. Each water quality impact monitoring was scheduled such that the interval between two water quality impact monitoring was more than 36 hours to record representative water quality data throughout the week.

Two (2) replicate in-situ measurements and samples were collected at each monitored water depth of each designated monitoring stations. Dissolved Oxygen (DO), pH value, salinity, temperature and turbidity were measured in-situ whereas the level of suspended solids (SS) were determined by SGS Hong Kong Limited which is a HOKLAS accredited laboratory.

The calculated Action and Limit Levels of water quality monitoring with reference to the Baseline Water Quality Monitoring Report are provided in Table 2.9.

Table 2.9 Calculated Action and Limit Levels for Water Quality

Parameter	Action Level	Limit Level
San Tin Eastern Main Drainage Channel (STEMDC) - Station D1’
DO in mg/L ^(a)	1.2 mg/L	1.2 mg/L
SS in mg/L ^{(b), (c)}	105 mg/L, or 120% of upstream control station’s (U1a) SS recorded on the same day	113 mg/L, or 130% of upstream control station's (U1a) SS recorded on the same day
Turbidity in NTU ^{(b), (c)}	97 NTU, or 120% of upstream control station’s (U1a) turbidity recorded on the same day	102 NTU, or 130% of upstream control station's (U1a) turbidity recorded on the same day
San Tin Western Main Drainage Channel (STWMDC) - Stations D2a, D2b’, D2c and D2d
DO in mg/L ^(a)	1.3 mg/L	1.1 mg/L
SS in mg/L ^{(b), 3}	38 mg/L, or 120% of upstream control stations’ (U2a and U2b) SS recorded on the same day	46 mg/L, or 130% of upstream control stations’ (U2a and U2b) SS recorded on the same day
Turbidity in NTU ^{(b), (c)}	42 NTU, or 120% of upstream control stations’ (U2a and U2b) turbidity recorded on the same day	52 NTU, or 130% of upstream control stations’ (U2a and U2b) turbidity recorded on the same day
Small Watercourses along Sam Tam Road - Station D7
DO in mg/L ^(a)	0.6 mg/L	0.6 mg/L
SS in mg/L ^(b)	5 mg/L	5 mg/L
Turbidity in NTU ^(b)	11 NTU	12 NTU
Small Watercourses near Mai Po Village - Station D8
DO in mg/L ^(a)	1.4 mg/L	1.2 mg/L
SS in mg/L ^(b)	7 mg/L	8 mg/L
Turbidity in NTU ^(b)	12 NTU	13 NTU

Note(s):

(a) For DO, non-compliance of the water quality limits occurs when monitoring result is lower than the limits.

(b) For SS and turbidity, non-compliance of the water quality limits occurs when monitoring result is higher than the limits

(c) For clarity, the exceedance of Action / Limit Levels for SS and turbidity is considered to occur when both the baseline percentile criteria (based on 95%-ile / 99%-ile of collected baseline data) and control station criteria (based on 120% / 130% of control station data collected on the same day during impact monitoring) are exceeded. In case more than one upstream control station is involved, the higher number would be considered as the control criteria. Exceeding either the baseline percentile criteria or control station criteria alone does not constitute the exceedance of the corresponding Action / Limit Levels.

The locations of the monitoring stations under works contracts ND/2024/09 and ND/2024/10 are shown in Figure 2.3 and Table 2.10.

Table 2.10 Locations of Impact Water Quality Monitoring Stations and Monitoring Requirements

Monitoring Station	Coordinates		Description	Parameters	Frequency	Monitoring Dates
Monitoring Station	Easting	Northing	Description	Parameters	Frequency	Monitoring Dates
U1a	826721	838781	Upstream Station	In-situ measurements • DO (mg/L) • DO Saturation (%) • Salinity • Temperature (℃) • pH • Turbidity (NTU) Laboratory measurements • SS (mg/L)	3 days per week during the construction period of the relevant works contracts of the Project.	30 September 2025
U1b’ ^(a)	827146	840550	Upstream Station (Alternative Monitoring location of U1b)
G1a	826686	839212	Gradient Station
G1b	826472	839908	Gradient Station
G1c	826339	840303	Gradient Station
G1d	826316	840657	Gradient Station
D1’ ^(b)	825363	841421	Impact Station
U2a	826181	838334	Upstream Station			19, 22, 26 and 29 September 2025 ^(c)
U2b’ ^(b)	825517	838767	Upstream Station (Alternative Monitoring location of U2b)
G2	825588	839518	Gradient Station
D2a	825200	839396	Impact Station
D2b’ ^(b)	824726	840168	Impact Station (Alternative Monitoring location of D2b)
D2c	824846	840373	Impact Station
D2d	825239	839846	Impact Station
D7	824254	838831	Impact Station
D8	824188	839310	Impact Station

Note(s):

(a) Alternative water quality monitoring station U1b’ is used as fall-back option in case sampling at original monitoring station of U1b as per EM&A Manual is not practical due to low flow condition.

(b) Alternative water quality monitoring stations D1’, D2b’ and U2b’ have been adopted as replacements of the original stations D1, D2b and U2b as per EM&A Manual due to access limitations.

(c) Impact water quality monitoring for ND/2024/10 on 24 September 2025 was cancelled due to the approach of super typhoon Ragasa.

(a) The relevant monitoring stations for each works contract are listed below:

- ND/2024/09: U2a, U2b’, G2, D2a, D2b’, D2c, D2d, D7, D8

- ND/2024/10: U1a, U1b’, G1a, G1b, G1c, G1d, D1’

The equipment used in the impact water quality monitoring work is summarised in Table 2.11 below. Copies of the calibration certificates are attached in Annex F1.

Table 2.11 Water Quality Monitoring Equipment

Parameters (Unit)	Equipment
In-situ Measurement
Dissolved Oxygen (mg/L and % of saturation)	HORIBA U-50 Series U53 (S/N: FXMONLLF) YSI ProDSS (S/N: 19C102067/19C000245)
Salinity (ppt)
Temperature (°C)
pH
Turbidity (NTU)
Current Velocity (m/s)	雲境天合 LS300-B
Laboratory Analysis
Suspended Solids (SS) (mg/L)	Sample Container: 1L Clear Plastic Bottle

2.3.2 Monitoring Schedule for the Reporting Month

The schedule for water quality monitoring during the reporting period is provided in Annex F2.

2.3.3 Results and Observations

A total of five (5) monitoring events for impact water quality monitoring were conducted at all designated monitoring stations in the reporting period. Due to the hoisting of signal No. 8 and above of super typhoon Ragasa from 23 to 24 September 2025, the scheduled water quality monitoring on 24 September 2025 was cancelled. Impact water quality monitoring results and graphical presentations are provided in Annex F3.

No exceedance of Action and Limit Levels was recorded for impact water quality monitoring in the reporting period. No action was thus required to be undertaken in accordance with the Event and Action Plan presented in Annex F4.

2.4 EM&A Site Inspection

Site inspections were carried out on a weekly basis with the Contractor and ER to monitor the implementation of proper environmental pollution control and mitigation measures for air quality, noise, water quality, waste management, landscape and visual impacts under the Project. In the reporting period, one (1) site inspection was carried out on 30 September 2025 for ND/2024/09, and two (2) site inspections were carried out on 18 and 26 September 2025 for ND/2024/10.

Key observations during the site inspections are summarized in Table 2.12.

Table 2.12 Key Observations Identified during the site inspection in this Reporting Month

Inspection Date	Environmental Observations	Follow-up Status
ND/2024/09
30 September 2025	Nil.	Nil.
ND/2024/10
18 September 2025	• Temporary mitigations to prevent surface water runoff should be provided (e.g. sandbags). • Generators should be provided with full enclosures. • Stockpile should be covered (e.g. by tarpaulin sheets).	• Sandbags were provided to prevent surface water runoff. • Full enclosure will be provided as soon as possible. The enclosure with water-filled barrier was provided as temporary measure. • Water spraying has been provided for the stockpile.
26 September 2025	• Accumulation of stagnant water was observed on site. The Contractor was reminded to clear the stagnant water. • Accumulation of excavated materials was observed on site. The Contractor was reminded to provide coverings for the excavated materials. • No non-road mobile machinery (NRMM) label was displayed for the excavator. The Contractor was reminded to display NRMM label for the excavator.	· Stagnant water had been removed off site. · Materials had been removed off site. · NRMM label is displayed.

2.5 Waste Management

Waste generated from the Works Contracts of the Project include inert construction and demolition (C&D) materials and non-inert C&D wastes. Sorting of C&D materials was carried out on site. Sufficient numbers of receptacles were available for general refuse collection and sorting.

Reference has been made to the waste flow tables prepared by the Contractors. The quantities of different types of waste are summarised in Table 2.13. Details of cumulative waste management data are presented as a waste flow table in Annex G.

Table 2.13 Quantities of Waste Generated in Reporting Period

Month	Contract No.	Inert C&D Materials ^{(a) (b)} (m³)	Imported Fill ^(c) (m³)	Inert Construction Waste Reused ^(d) (m³)	Non-inert Construction Waste ^(e)(tonnes)	Recyclable Materials ^(f) (tonnes)	Chemical Waste (tonnes)
September 2025	ND/2024/09	0.00	0.00	0.00	136.07	0.00	0.00
	ND/2024/10	13.75	0.00	0.00	27.95	0.00	0.00
	Sub-total	13.75	0.00	0.00	164.02	0.00	0.00

Note:

(a) Inert construction wastes include hard rock and large broken concrete, and materials disposed as public fill.

(b) The conversion factor for inert C&D Materials for ND/2024/10 is 2.4 tonnes/m³.

(d) Reuse of inert construction waste generated under the Project.

(e) Non-inert construction wastes include general refuse disposed at landfill.

(f) Recyclable materials include metals, paper, cardboard, plastics and others.

2.6 Implementation Status of Environmental Mitigation Measures

A summary of the Environmental Mitigation Implementation Schedule is presented in Annex H. The necessary mitigation measures were implemented properly for the Project.

2.7 Summary oF Complaints, Notification OF Summons AND Successful Prosecutions

There was no notification of summons or prosecution recorded in the reporting period.

3. Future Key Issues

3.1 Construction Programme for the coming Three Months

Works to be undertaken in the next three months are summarised in Table 3.1 below, together with key issues and the key mitigation measures.

Table 3.1 Major Construction Works in the Next Three MOnths

Construction Works to be Undertaken

Key Issues

Key Mitigation Measures

Contract No. ND/2024/09

• Topographic Survey

• Ground Investigation Work

• Wetland Enhancement Works

• Soldier Pile Wall Construction

• Tree Felling

• Demolition Works

• Site Formation Works

• Dust emission

• Handling and storage of C&D materials

• Noise from use of PME

• Emission of dark smoke from PMEs

• Proper discharge of wastewater

• Prevention and proper discharge of surface runoff

• Tree protection

• Good site practices

• Regular water spraying on stockpiles

• Provide tarpaulin sheets coverage on stockpiles and reuse of C&D materials as far as practicable

• Use of QPME and noise barrier/acoustic mat/enclosure

• Regular maintenance of PMEs

• Implementation of wastewater and drainage

management

• Retain and protect all existing trees and vegetation within the study area which are not directly affected by the works

Contract No. ND/2024/10

• Ground Investigation Work

• Construction Box Culvert

• Tree Felling

• Dust emission

• Handling and storage of C&D materials

• Noise from use of PME

• Emission of dark smoke from PMEs

• Proper discharge of wastewater

• Prevention and proper discharge of surface runoff

• Tree protection

• Good site practices

• Regular water spraying on stockpiles

• Provide tarpaulin sheets coverage on stockpiles and reuse of C&D materials as far as practicable

• Use of QPME and noise barrier/acoustic mat/enclosure

• Regular maintenance of PMEs

• Implementation of wastewater and drainage

management

• Retain and protect all existing trees and vegetation within the study area which are not directly affected by the works

The ET will keep track on the construction works to confirm compliance with environmental requirements and the proper implementation of all necessary mitigation measures. The ET will also recommend to the Contractors about the environmental toolbox topics on the abovementioned key issues for the next reporting period.

3.2 Monitoring Schedule for the Future 3 Months

The tentative schedules for environmental monitoring in October, November and December 2025 are provided in Annex I.

4. Conclusion and Recommendations

This EM&A Report presents the findings of the EM&A activities undertaken for the Project during the period of September 2025 in accordance with the EM&A Manual and the requirements of the EPs. The environmental monitoring, site inspection, environmental complaint handling and EM&A reporting in works areas under Contract Nos. ND/2024/09 and ND/2024/10 were covered and carried out.

Air quality (1-hour RSP, 24-hour rolling average RSP and 24-hour rolling average FSP), noise and water quality monitoring were carried out in the reporting period.

The monitoring results for air quality, noise and water quality monitoring complied with the Action/ Limit levels in the reporting period.

Environmental site inspections were carried out during the reporting period. Recommendations on remedial actions were given to the Contractors for the deficiencies identified during the site inspections.

There was no environmental complaint, notification of summons or prosecution recorded in the reporting period.

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