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Report title		Quarterly Environmental Monitoring and Audit (EM&A) Report – February 2025 to April 2025
Document code		QEM&A-05	Project number		P525672
File path
Client		Wing Tat Civil Engineering Co. Limited
Client contact			Client reference
Rev	Date	Revision details/status	Author	Reviewer	Verifier (if required)	Approver
0	2025-06-19	Draft	Oliver Chiu	F. C. Tsang		Kevin Li
1	2025-07-22	1^st revision	Oliver Chiu	F. C. Tsang		Kevin Li
2	2025-07-28	2^nd revision	Oliver Chiu	F. C. Tsang		Kevin Li
3	2025-07-30	3^rd revision	Oliver Chiu	F. C. Tsang		Kevin Li
Current revision		3

Approval
Author signature		Certified by
Name	Oliver Chiu	Name	F. C. Tsang
Title	Environmental Team Consultant	Title	Environmental Team Leader

Contents

Executive Summary. IV

1 Introduction. 1

1.1 Project Background. 1

1.2 Construction Works Programme. 2

1.3 Project Organisation. 2

1.4 Construction Works Programme and Construction Works Area. 3

1.5 Works undertaken during the Period. 3

2 Water Quality. 5

2.1 Monitoring Requirement. 5

2.2 Monitoring Location. 5

2.3 Monitoring Parameter and Frequency. 6

2.4 Action and Limit Level for Water Quality Monitoring.. 6

2.5 Event and Action Plan. 7

2.6 Results and Observations. 8

2.7 Quarterly Assessment of Construction Impacts on Suspended Solids at the Project Site. 9

3 Noise. 11

3.1 Monitoring Locations. 11

3.2 Noise Monitoring Parameter, Frequency and Duration. 11

3.3 Action and Limit Levels. 12

3.4 Results and Observations. 12

4 Ecology. 13

4.1 Freshwater Crab. 13

5 Waste Management. 15

6 Land Contamination. 16

7 Landscape and Visual. 17

7.1 Audit Requirements. 17

7.2 Results and Observations. 17

8 Cultural Heritage. 18

8.1 Archaeology. 18

8.2 Built Heritage. 19

9 Environmental Site Inspection and Audit. 13

9.1 Implementation Status of Environmental Mitigation Measures. 13

10 Summary of Monitoring Exceedance, Complaints, Notification of Summons and Prosecutions. 15

10.1 Summary of Exceedance. 15

10.2 Summary of Environmental Non-Compliance. 16

10.3 Summary of Environmental Complaint. 16

10.4 Summary of Environmental Summon and Successful Prosecution. 18

11 Conclusions and Recommendations. 19

11.1 Conclusion. 19

11.2 Comments/ Recommendations. 20

Appendices

Appendix 1.1 Construction Programme

Appendix 1.2 Project Organization Chart

Appendix 2.1 Event and Action Plans for Water Quality

Appendix 2.2 Graphical Presentation of Water Quality Monitoring

Appendix 3.1 Event and Action Plans for Noise

Appendix 3.2 Graphical Presentation of Noise Monitoring

Appendix 5.1 Waste Flow Table

Appendix 10.1 Complaint Log

Figures

Figure 1.2.. Location of Work Areas for the Project

Figure 2.1.. Impact Water Quality Monitoring Locations

Figure 3.1.. Impact Noise Monitoring Locations

Figure 8.1.. Area for Archaeological Survey

Figure 8.2.. Layout plan showing distance between the works area at Ha Che and the Lan Fong Study Hall

Figure 8.3.. Monitoring Locations of Lan Fong Study Hall at Ha Che

Figure 8.4.. Monitoring Locations of St. John’s Chapel near Tai Wo

Executive Summary

A1. Drainage Services Department (DSD) has appointed Aurecon Hong Kong Limited (Aurecon) to undertake the Environmental Team services for the project and implement the EM&A works.

A2. The construction works commenced on 20 February 2024.

A3. This 5^th Quarterly Environmental Monitoring and Audit (EM&A) Report is prepared for Contract No. DC/2022/02 Drainage Improvement Works at Yuen Long – Stage 2 (hereinafter called the “Contract”). The report summaries the findings of the EM&A programme during the reporting period from 1 February 2025 to 30 April 2025.

Key Construction Works in the Reporting Period

A4. A summary of construction activities undertaken during the reporting period is presented below:

Ha Che

§ Site clearance;

§ Breaking ground;

§ Temporary drainage diversion;

§ Excavation and Lateral Support, relocate/ divert utilities, rebar fixing, formwork erection and cast-in, concreting;

§ Sheet pilling & backfilling and compaction; and

§ Removal of sheet piles, drain laying works, reinstatement.

Lin Fa Tei

§ Site clearance;

§ Temporary drainage diversion;

§ Excavation and Lateral Support, relocate/ divert utilities, rebar fixing, formwork erection and cast-in, concreting; and

§ Sheet pilling & backfilling and compaction;

§ Removal of sheet piles, drain laying works, reinstatement.

Sung Shan New Village

§ Site clearance;

§ Temporary drainage diversion;

§ Excavation and Lateral Support, relocate/ divert utilities, rebar fixing, formwork erection and cast-in, concreting;

§ Sheet pilling & backfilling and compaction; and

§ Removal of sheet piles, drain laying works, reinstatement.

Tai Wo

§ No construction activities (from 1 April 2025 to 30 April 2025)

§ Site Clearance

§ Temporary Drainage Diversion

§ Excavation and Lateral Support, Relocate/ Divert Utilities, Rebar Fixing, Formwork Erection and Cast-in, Concreting

Breaches of Environmental Quality Performance Limits

Water Quality

A5. The summary of exceedance records during the reporting period is summarized in Table A1.

Table A1 Summary of Exceedance Records of Water Quality Monitoring

Parameter	No. of non-project related exceedances		Total No. of non-project related exceedances	No. of exceedance related to the Project		Total No. of exceedance related to the Project
Parameter	AL	LL	Total No. of non-project related exceedances	AL	LL	Total No. of exceedance related to the Project
Dissolved Oxygen (DO)	1	0	1	0	0	0
Turbidity	0	0	0	0	0	0
Suspended Solids (SS)	0	0	0	0	0	0

A6. One (1) action level exceedance for DO were recorded during the reporting period. After investigation of above the exceedances, it was considered to non-project related.

Noise

A7. No Action Level or Limit Level exceedance was recorded for construction noise monitoring during the reporting period.

Built Heritage

A8. No monitoring exceedance was recorded in the reporting period.

Complaint Log

A9. Two environmental complaints were received during the reporting period. The investigation results for the environmental complaint regarding air quality and environmental complaint regarding waste management on 19 February 2025 had been investigated during the reporting period. The summary of the investigation results was presented below:

Environmental Complaint regarding air quality on 19 February 2025

A10. It was recorded that a complaint regarding air quality was received by the EPD on 17 February 2025 and referred to DSD, ET and IEC on 19 February 2025. The complaint was related to the lack of dust suppression measures from the construction site at Tai Wo.

A11. Under the investigation, the precautionary dust suppression measures were implemented on site before and on 17 February 2025 by the contractor. The following measures included:

§ Regular watering had been provided for excavated works sites and main haul road;

§ Water spraying for vehicle wheeling washing and dust suppression at the exit of the construction sites;

§ Paving haul road with concrete to reduce generation of fugitive dust during vehicle travelling; and

§ Covering open stockpiles.

A12. To enhance the dust suppression on site, the Contractor had implemented the following measures after 17 February 2025:

§ Increasing watering frequency on excavated work sites and main haul roads;

§ Ensuring all excavated work sites and main haul roads had adopted proper and regular watering;

§ Ensuring water spraying for vehicle wheel washing and dust suppression has been adopted at the exit of the construction sites; and

§ Avoiding open stockpiles placing near air sensitive receivers and ensuring that the stockpiles are covered with tarpaulin when they are not in use.

A13. During the site investigation conducted by the ET at Tai Wo on 21 February 2025, the ET observed that:

§ No muddy material on the main access road adjacent to the construction site;

§ Water spraying has been adopted on main haul road and exposed area;

§ Water spraying for vehicle wheel washing and dust suppression has been adopted at the exit of the construction sites. Cleaning has been deployed to prevent muddy stain left

§ behind on public access road;

§ Stockpiles are covered with tarpaulin; and

§ No observation of fugitive dust.

A14. Based on the information provided by the Contractor and information collected from the site inspection, it concluded that dust suppression measures have been properly implemented on site to mitigate dust impact on the nearby residents. No deficiency observation in relation to fugitive dust impact were recorded during the site inspections on 21 February 2025. After the complaint, the Contractor has enhanced and properly implemented the precautionary and mitigation measures to suppress dust from the work area and within the site boundary. As no further complaint of lacking dust suppression measures was received, the case is considered closed.

Environmental Complaint regarding waste management on 19 February 2025

A15. It was recorded that a complaint regarding waste management was received by the EPD on 16 February 2025 and referred to the DSD, the ET and the IEC on 19 February 2025. The complaint was related to the fly-tipping of construction waste from the construction site at Tai Wo.

A16. A site investigation was conducted by the ET at Tai Wo on 21 February 2025. During the site investigation, the ET observed that:

§ No construction waste was found within the work area at Tai Wo;

§ Stockpile of materials within the site working area was properly covered with tarpaulin;

§ A construction working area that is not related to the Project was observed near the vehicle washing facility. Construction materials that are not related to the Project were found near the vehicle washing facility but were lying outside the working area.

A17. No environmental deficiency was observed during the site investigation on 21 February 2025.

A18. Based on the information provided by the Contractor and the information collected from the site inspection, no construction waste was observed at the work area in Tai Wo. Construction materials that were considered as project non-related, was observed on the public access road at Cheung Po Tsuen. Therefore, it is concluded that the complaint is invalid.

Notification of Summons and Successful Prosecutions

A19. No notification of summons or successful prosecutions was received in the reporting period.

Reporting Changes

A20. Construction works at Tai Wo are only allowed during dry season (i.e. October to March) in accordance with Condition 3.2 of EP No. EP-596/2021. Impact noise monitoring, impact water quality monitoring and weekly site inspection at Tai Wo were resumed starting from 1 February 2025 during the last dry season (i.e. October 2024 to March 2025). The construction work at Tai Wo was temporarily suspended since 1 April 2025 in accordance with the requirement stipulated in Condition 3.2 of EP No. EP-596/2021, thus, no impact noise monitoring, impact water quality monitoring and weekly site inspection was carried out during the above period.

1 Introduction

1.1 Project Background

1.1.1 The Drainage Master Plan Studies for the Yuen Long, Kam Tin, Ngau Tam Mei and Tin Shui Wai Drainage Basin (YLDMP) were completed in 1998. The majority of the improvement works in Yuen Long and Kam Tin recommended under the YLDMP Study have been completed. Since completion of the DMP Studies, there have been changes in developments within the areas and new development proposals and town planning studies were commissioned. In addition, some new flooding complaints were received at the upstream areas of the drainage basins, indicating that further improvement to the drainage systems was required.

1.1.2 The Drainage Services Department (DSD) commissioned the “Review of Drainage Master Plans in Yuen Long and North Districts – Feasibility Study” (the Review Study) in 2008 so that the new development scenarios could be incorporated and the effectiveness of the previously recommended works could also be assessed. The Review Study completed in end 2011 identified that some areas in Yuen Long District could not meet the required flood protection level according to the latest land use changes and future developments taking into account various factors, including sedimentation at the downstream main channels, mangrove growth at river estuaries, updated extreme sea level statistics at Tsim Bei Tsui and projected climate change impacts, in the hydraulic analysis. To account for the severity and extent of possible flooding and the works implementation time, the Review Study proposed drainage improvement works in Yuen Long District.

1.1.3 Atkins China Ltd (ACL) was commissioned by the DSD in November 2013 to undertake an Investigation, Design and Construction Consultancy entitled “Agreement No. CE 22/2013 (DS) Drainage Improvement Works in Yuen Long, Stage 1 – Investigation, Design and Construction” (hereinafter called the Assignment). The Project comprises construction of drainage improvement works to four villages (namely Sung Shan New Village, Tai Wo, Lin Fa Tei and Ha Che) including landscaping, waterscaping, utilities diversion, temporary traffic arrangements, re-provisioning / improvements to existing dry weather flow intercepting system and any other works incidental to the completion of the Project.

1.1.4 An Environmental Impact Assessment (EIA) Study Brief (ESB-279/2014) for four villages namely Ha Che, Tai Wo, Lin Fa Tei and Sung Shan New Village which is a designated project was issued by the Environmental Protection Department (EPD) on 14 October 2014.

1.1.5 The EIA Report for Drainage Improvement Works Near Four Villages in Yuen Long – Sung Shan New Village, Tai Wo, Lin Fa Tei and Ha Che (referred to as “the Project”) (Register No. AEIAR-229/2021) was approved on 3 June 2021 and the Environmental Permit (EP) EP-596/2021, covering the Upgrading, Construction and Deepening of the Project was granted on 28 September 2021.

1.1.6 Aurecon Hong Kong Limited (Aurecon) is commissioned by the Wing Tat Civil Engineering Co. Limited to undertake the Environmental Team (ET) services and carry out the Environmental Monitoring and Audit (EM&A) for Drainage Improvement Works Near Four Villages in Yuen Long - Sung Shan New Village, Tai Wo, Lin Fa Tei and Ha Che (Register No. EP-596/2021).

1.1.7 This is the 5^th Quarterly EM&A Report summarizing the key findings of the construction phase EM&A programme from 1 February 2025 to 30 April 2025 (the reporting period) and is submitted to fulfil the requirements in Section 12.3 of the approved Updated EM&A Manual of the Project.

1.2 Construction Works Programme

1.2.1 The construction programme and the location plan of the Project are shown in Appendix 1.1 and Figure 1.1 respectively. The locations of the proposed drainage improvement work at the four villages are presented in Figures 1.2a to Figures 1.2d.

1.3 Project Organisation

1.3.1 Involvement of relevant parties in a collaborative and interactive manner is essential for the implementation of the recommended EM&A programme. The following sections outline the primary responsibilities and duties of the key EM&A programme participants. The lines of communication with respect to EM&A works are shown in Diagram 1.1.

Diagram 1.1 Organisation Chart

1.3.2 Parties with different levels of involvement in the Project organisation are summarized in Table 1.1.

Table 1.1 Parties Involved in Project Organisation

Parties	Organization / Company
Project Proponent	Drainage Services Department
Supervisor / Engineer’s Representative (ER)	Atkins China Ltd
Contractor	Wing Tat Civil Engineering Co. Limited
Environmental Team (ET)	Aurecon Hong Kong Limited
Independent Environmental Checker (IEC)	Mott MacDonald Hong Kong Limited

1.3.3 The key personnel contact names and numbers are summarized in Appendix 1.2.

1.4 Construction Works Programme and Construction Works Area

1.4.1 The construction works commenced on 20 February 2024. The construction works programme and the construction works area of the Project are shown in Appendix 1.1 and Figure 1.1 respectively.

1.5 Works undertaken during the Period

1.5.1 The main construction works carried out in the reporting period were as below.

Ha Che

§ Site clearance; work

§ Breaking ground

§ Temporary drainage diversion

§ Excavation and Lateral Support, relocate/ divert utilities, rebar fixing, formwork erection and cast-in, concreting

§ Sheet pilling & backfilling and compaction; and

§ Removal of sheet piles, drain laying works, reinstatement.

Lin Fa Tei

§ Site clearance work

§ Temporary drainage diversion

§ Excavation and Lateral Support, relocate/ divert utilities, rebar fixing, formwork erection and cast-in, concreting; and

§ Sheet pilling & backfilling and compaction

§ Removal of sheet piles, drain laying works, reinstatement.

Sung Shan New Village

§ Site clearance work

§ Temporary drainage diversion

§ Excavation and Lateral Support, relocate/ divert utilities, rebar fixing, formwork erection and cast-in, concreting

§ Sheet pilling & backfilling and compaction; and

§ Removal of sheet piles, drain laying works, reinstatement.

Tai Wo

§ No construction activities (from 1 April 2025 to 30 April 2025)

§ Site Clearance work

§ Temporary Drainage Diversion

§ Excavation and Lateral Support, Relocate/ Divert Utilities, Rebar Fixing, Formwork Erection and Cast-in, Concreting

1.5.2 The environmental mitigation measures corresponding to the main construction works implemented in the reporting period can be referred to Appendix 1.3.

2 Water Quality

2.1 Monitoring Requirement

2.1.1 In accordance with the approved Updated EM&A Manual, impact water quality monitoring should be carried out three days per week at all designated monitoring stations during the construction period. The interval between two sets of monitoring should not be less than 36 hours.

2.1.2 Replicate in-situ measurements of dissolved oxygen (DO), temperature, pH, turbidity, salinity, water depth and suspended solids (SS) for each independent sampling event shall be collected to ensure a robust statistically interpretable database.

2.2 Monitoring Location

2.2.1 Impact water quality monitoring was conducted at 8 monitoring stations (except Station C4 & C5) from 1 April 2025 to 30 April 2025 and conducted at 10 monitoring stations from 1 February 2025 to 31 March 2025 which is summarized in Table 2.1. The location of water quality monitoring stations is shown in Figure 2.1a to Figure 2.1d.

Table 2.1 Summary of Impact Water Quality Monitoring Stations

Stream	Monitoring ID	Coordinates (HK Grid)		Remarks
Stream	Monitoring ID	Easting	Northing	Remarks
SSNV	C1A ⁽¹⁾	821702	831945	Alternative Impact Monitoring Point
	C2	822459	831470	Control Monitoring Point
	C3A ⁽²⁾	822413	831284	Alternative Control Monitoring Point
TW	C4 ⁽⁴⁾	825497	830664	Control Monitoring Point
TW	C5 ⁽⁴⁾	825486	830716	Impact Monitoring Point
LFT	C6	827232	831713	Control Monitoring Point
	C7A ⁽³⁾	826865	832115	Alternative Control Monitoring Point
	C8	826513	832075	Impact Monitoring Point
HC	C9	828304	835029	Control Monitoring Point
HC	C10	827919	834271	Impact Monitoring Point

Notes:

(1) At Station C1, access to safe sampling of water is not feasible due to steep banks on both sides of the stream channel. An alternative monitoring location is proposed at Station C1A, which is about 250 m along the same stream channel downstream of Station C1 and is accessible for safe water sampling.

(2) During the first day of baseline monitoring at Station C3, shallow water was observed, and the ET could not sample enough water for monitoring. As agreed by the ER, the Contractor, and the IEC, a new sampling location, Station C3A, was identified at about 130 m upstream and was accessible for water sampling.

(3) For Station C7, the location is not close to the nearest, revised works boundary (about 200 m away). An alternative monitoring location is proposed at Station C7A, which is about 23 m upstream of the nearest, revised works boundary.

(4) Construction works at Tai Wo are only allowed during dry season (i.e. October to March) in accordance with Condition 3.2 of EP No. EP-596/2021. Impact water quality monitoring at Tai Wo were resumed starting from 1 February 2025 during the last dry season (i.e. October 2024 to March 2025). The construction work at Tai Wo was temporarily suspended since 1 April 2025 in accordance with the requirement stipulated in Condition 3.2 of EP No. EP-596/2021, thus, no impact noise monitoring, impact water quality monitoring and weekly site inspection was carried out during the above period.

2.3 Monitoring Parameter and Frequency

2.3.1 The monitoring parameters, frequency and duration of impact water quality monitoring are listed in Table 2.2.

Table 2.2 Parameters measured in the Impact Water Quality Monitoring

Parameter	Frequency	Duration	Stream	Monitoring ID
Dissolved oxygen (DO), temperature, turbidity, salinity, pH, stream water depth and suspended solids (SS)	1 day in a week⁽¹⁾	Throughout the construction phase	SSNV	C1A
				C2
				C3A
			LFT	C6
				C7A
				C8
			HC	C9
				C10
	3 days in a week		TW⁽²⁾	C4
				C5

Notes:

(1) Impact monitoring shall be carried out 3 days per week during the construction process. The monitoring frequency can be reduced to once per week, with sampling/ measurement at the designated monitoring locations when no exceedances were recorded during the past three-month period in accordance with Section 2.7, Appendix 4 of the Updated EM&A Manual. The change of the monitoring frequency at SSNV, LFT and HC was approved by EPD on 25 November 2024. Hence, the monitoring frequency at SSNV, LFT and HC was changed to 1 day in a week starting from 2 December 2024.

(2) No construction work would be undertaken at Tai Wo between April and September under Condition 3.2 of EP No.: EP-596/2021. Thus, impact water quality monitoring at C4 and C5 was suspended in April 2025.

2.3.2 Monitoring location and position, time, sampling depth, weather conditions and any special phenomena or work underway nearby are recorded during the impact monitoring.

2.4 Action and Limit Level for Water Quality Monitoring

2.4.1 The criteria of action and limit levels for water quality monitoring are defined in Table 2.3.

Table 2.3 Action and Limit Levels for Water Quality

Parameters	Action Level	Limit Level
DO in mg/L	< 5%-ile of baseline data	< 4 mg/L or < 1%-ile of baseline data
SS in mg/L	> 95%-ile of baseline data or >120% of upstream control station of the same day, whichever is higher	> 99%-ile of baseline data or 130% of upstream control station of the same day, whichever is higher
Turbidity in NTU	> 95%-ile of baseline data or >120% of upstream control station of the same day, whichever is higher	> 99%-ile of baseline data or > 130% of upstream control station of the same day, whichever is higher

Note:

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

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

(3) All the figures given in the table are used for reference only and the EPD may amend the figures whenever it is considered necessary.

2.4.2 Based on the criteria listed in Table 2.3, the action and limit levels for water quality are determined in Table 2.4.

Table 2.4 Action and Limit Levels of Water Quality

Stream	Monitoring ID	Parameters	Action	Limit
SSNV	C1A	DO in mg/L	<6.72	<4 ⁽¹⁾
		SS in mg/L	>7.3 or >120% of upstream control station of the same day, whichever is higher	>8.5 or > 130% of upstream control station of the same day, whichever is higher
		Turbidity in NTU	>10.37 or >120% of upstream control station of the same day, whichever is higher	>10.81 or > 130% of upstream control station of the same day, whichever is higher
TW	C5	DO in mg/L	<8.36	<4 ⁽²⁾
		SS in mg/L	>9.9 or > 120% of upstream control station of the same day, whichever is higher	>10.0 or > 130% of upstream control station of the same day, whichever is higher
		Turbidity in NTU	>13.64 or > 120% of upstream control station of the same day, whichever is higher	>13.87 or > 130% of upstream control station of the same day, whichever is higher
LFT	C8	DO in mg/L	<5.38	<4 ⁽³⁾
		SS in mg/L	>6.3 or > 120% of upstream control station of the same day, whichever is higher	>7.0 or > 130% of upstream control station of the same day, whichever is higher
		Turbidity in NTU	>12.46 or > 120% of upstream control station of the same day, whichever is higher	>12.94 or > 130% of upstream control station of the same day, whichever is higher
HC	C10	DO in mg/L	<2.55	<2.43 ⁽⁴⁾
		SS in mg/L	>8.7 or > 120% of upstream control station of the same day, whichever is higher	>8.8 or > 130% of upstream control station of the same day, whichever is higher
		Turbidity in NTU	>20.06 or > 120% of upstream control station of the same day, whichever is higher	>21.07 or > 130% of upstream control station of the same day, whichever is higher

Notes:

(1) The 1%-ile of baseline DO data at C1A is 6.61 mg/L, which is higher than 4 mg/L. Thus, DO concentration of 4 mg/L, which is in line with the Water Quality Objectives, is adopted as the limit level.

(2) The 1%-ile of baseline DO data at C5 is 8.09 mg/L, which is higher than 4 mg/L. Thus, DO concentration of 4 mg/L, which is in line with the Water Quality Objectives, is adopted as the limit level.

(3) The 1%-ile of baseline DO data at C8 is 5.36 mg/L, which is higher than 4 mg/L. Thus, DO concentration of 4 mg/L, which is in line with the Water Quality Objectives, is adopted as the limit level.

(4) The 1%-ile of baseline DO data at C10 is 2.43 mg/L, which is lower than 4 mg/L. Taking account of the baseline water quality condition and to minimise any false alarm of water quality deterioration during construction phase, DO concentration of 2.43 mg/L is adopted as the limit level.

2.5 Event and Action Plan

2.5.1 Should any non-compliance of the criteria occur, action in accordance with the Event and Action Plan in Appendix 2.1 shall be followed. Investigation of the exceedances of environmental quality performance limits should be conducted, and the ET will immediately notify the IEC and EPD, as appropriate. The notification should be followed up with advice to the IEC and EPD on the results of the investigation, proposed actions and success of the action taken, with any necessary follow-up proposals.

2.6 Results and Observations

2.6.1 The detailed monitoring results during the reporting period are reported in the monthly EM&A Reports. The graphical presentation of water quality monitoring at the monitoring stations are shown in Appendix 2.2.

2.6.2 One (1) action level exceedance for DO were recorded during the reporting period. After investigation of above the exceedances, it was considered to non-project related.

2.6.3 The summary of exceedance records of water quality monitoring during the reporting period is summarized in Table 2.5.

Table 2.5 Summary of Exceedance Records of Water Quality Monitoring

Parameter	No. of non-project related exceedances		Total No. of non-project related exceedances	No. of exceedance related to the Project		Total No. of exceedance related to the Project
Parameter	AL	LL	Total No. of non-project related exceedances	AL	LL	Total No. of exceedance related to the Project
Dissolved Oxygen	1	0	1	0	0	0
Turbidity	0	0	0	0	0	0
Suspended Solids	0	0	0	0	0	0

Action Level Exceedance for DO on 28 March 2025

2.6.4 Action level exceedance for DO at C5 was recorded on 28 March 2025. According to the Contractor’s information, pouring concrete for rectangular channel wall was carried out on site. No effluent was discharged off-site and no accidental site runoff was reported on 28 March 2025. Following the review of the monitoring results of regular water quality monitoring held on 28 March 2025 and additional monitoring held on 29 March 2025, it is noted that the DO levels at both the control station (C4) upstream of the works site and the impact station (C5) downstream of the works site are lower than the baseline levels. As no anthropogenic pollution source was identified upstream of the site during the water quality monitoring, it is considered that the non-compliance of DO action level was related to natural fluctuation of water flow. No evidence was found to indicate that the exceedance on 28 March 2025 was related to the construction works on site. No monitoring was carried out on 30 March 2025 (Sunday) when construction works were not undertaken. Regular monitoring was carried out on 31 March 2025. No further exceedances of action or limit levels were observed on the monitoring results of 31 March 2025.

2.7 Quarterly Assessment of Construction Impacts on Suspended Solids at the Project Site

2.7.1 The comparison of the difference between the quarterly mean and 1.3 times of the ambient mean is presented in Table 2.6.

Table 2.6 Comparison of the difference between the quarterly mean and 1.3 times of the ambient mean

Parameter	Monitoring Location	Quarterly Mean of SS (mg/L)	Baseline Level of SS (mg/L)	1.3 Times of Ambient Mean (mg/L) ⁽¹⁾	Quarterly Mean of SS > 1.3 Times of Ambient Mean (Y/N)	Request of Further Mitigation Measures (Y/N)
Suspended Solids	C1A	3.6	4.8	6.2	N	N
	C2 (Control Point)	8.5	3.2	4.2	Y	N/A
	C3A (Control Point)	4.8	2.2	2.9	Y	N/A
	C4 (Control Point)	32.1	10.7	13.9	Y	N/A
	C5	2.1	5.2	6.8	N	N
	C6 (Control Point)	17.0	3.7	4.8	Y	N/A
	C7A (Control Point)	8.0	6.7	8.7	N	N/A
	C8	2.3	4.0	5.2	N	N
	C9 (Control Point)	11.7	5.9	7.7	Y	N/A
	C10	4.6	8.5	11.1	N	N

Note:

(1) 1.3 times of the ambient mean equal to be defined as 30% increase of the baseline data.

Sung Shan New Village (Monitoring Locations C1A, C2 & C3A)

2.7.2 The quarterly mean of SS at Monitoring Location C1A (Impact Point) (3.6 mg/L) is lower than the 1.3 times of the ambient mean (6.2 mg/L). Hence, no further mitigation measures for control of water quality impact are required at Sung Shan New Village.

Tai Wo (Monitoring Locations C4 & C5)

2.7.3 The quarterly mean of SS at Monitoring Location C5 (Impact Point) (2.1 mg/L) is lower than 1.3 times of the ambient mean (6.8 mg/L). Hence, no further mitigation measures for control of water quality impact are required at Tai Wo.

Lin Fa Tei (Monitoring Locations C6, C7A & C8)

2.7.4 The quarterly mean of SS at Monitoring Location C8 (Impact Point) (2.3 mg/L) is lower than the 1.3 times of the ambient mean (5.2 mg/L). Hence, no further mitigation measures for control of water quality impact are required at Lin Fa Tei.

Ha Che (Monitoring Locations C9 & C10)

2.7.5 The quarterly mean of SS at Monitoring Location C10 (Impact Point) (4.6 mg/L) is lower than the 1.3 times of the ambient mean (11.1 mg/L). Hence, no further mitigation measures for control of water quality impact are required at Ha Che.

3 Noise

3.1 Monitoring Locations

3.1.1 The monitoring locations for construction noise monitoring are listed in Table 3.1 and shown in Figure 3.1a to Figure 3.1d.

Table 3.1 Noise Monitoring Stations during Construction Phase

ID No. ⁽¹⁾	Location	Nature of Uses	Type of Measurement
SSNV_M2	Village house next to a nullah in Tong Tai Po Tsuen (near DD118 1720 S.A)	Residential	Façade
SSNV_M3	Village house near a soybean sauce factory in Sung Shan New Village (near DD118 1712)	Residential	Façade
SSNV_M6	#43, Sung Shan New Village	Residential	Free-field
TW_M2 ⁽⁴⁾	#200, Cheung Po	Residential	Free-field
TW_M3 ⁽⁴⁾	Kai Yip Garden, #3H, Tai Wo	Residential	Free-field
LFT_M1	#2G, Lin Fa Tei	Residential	Façade
LFT_M3A ⁽²⁾	Near #125B, Lin Fa Tei	Residential	Free-field
LFT_M5	#156B, Lin Fa Tei	Residential	Façade
LFT_M6 ⁽³⁾	Village house near the nullah (DD112 699 S.E)	Residential	Façade
LFT_M11 ⁽²⁾	#210, Ngau Keng Tsuen	Residential	Façade
HC_M3A ⁽²⁾	Next to DD111 326 S.B RP near Fan Kam Road	-	Free-field
HC_M4	#1C, Chuk Hang	Residential	Façade
HC_M6	The Arbutus House 12, #52, Shui Kan Shek	Residential	Façade

Notes:

(1) SSNV – Sung Shan New Village; TW – Tai Wo; LFT – Lin Fa Tei; HC – Ha Che.

(2) LFT_M3A, LFT_M11, HC_M3A and are alternative noise monitoring stations proposed to replace LFT_M3, LFT_M13 and HC_M3, respectively.

(3) Due to the objection from property management office for providing access to designated monitoring location, the noise monitoring at LFT_M7 have been suspended since 27 March 2024. An alternative monitoring location LFT_M6 was proposed to replace LFT_M7 and agreed with the ER and the IEC.

(4) Construction works at Tai Wo are only allowed during dry season (i.e. October to March) in accordance with Condition 3.2 of EP No. EP-596/2021. Impact noise monitoring at Tai Wo was resumed starting from 1 February 2025 during the last dry season (i.e. October 2024 to March 2025). The construction work at Tai Wo was temporarily suspended since 1 April 2025 in accordance with the requirement stipulated in Condition 3.2 of EP No. EP-596/2021, thus, no impact noise monitoring, impact water quality monitoring and weekly site inspection was carried out during the above period.

3.2 Noise Monitoring Parameter, Frequency and Duration

3.2.1 Construction noise level was measured by the ET and measured in terms of the A-weighted equivalent continuous sound pressure level (L_eq). L_eq_(30mins) used as the monitoring parameter for the construction noise monitoring. The monitoring should be conducted during the construction phase between 0700 and 1900 on normal weekdays at the designated monitoring locations.

3.2.2 As supplementary information for data auditing, statistical results such as L10 and L90 were also obtained for reference.

3.2.3 Table 3.2 summarizes the monitoring parameters, duration, and frequency of construction noise monitoring.

Table 3.2 Construction Noise Monitoring Parameter, Frequency and Duration

Monitoring Station	Parameter	Frequency and Duration
SSNV_M2, SSNV_M3, SSNV_M6, HC_M3A, HC_M4, HC_M6, TW_M2, TW_M3, LFT_M1, LFT_M3A, LFT_M5, LFT_M6 and LFT_M11	L_eq_(30mins) (as a logarithmic average of 6 consecutive L_eq_(5mins))	Once every week throughout the construction phase between 0700 and 1900 on normal weekdays

3.3 Action and Limit Levels

3.3.1 The Action and Limit levels were established in accordance with the approved Updated EM&A Manual. Table 3.3 presents the Action and Limit Levels for construction noise. Should non-compliance of the criteria occur, action in accordance with the Event and Action Plan presented in Appendix 3.1 shall be carried out.

Table 3.3 Action and Limit Levels for Construction Noise Monitoring

Time Period	Action	Limit Level
07:00 – 19:00 on normal weekdays	When one or more documented complaints are received	75 dB(A)⁽¹⁾
07:00 – 23:00 on holidays; and 19:00 – 23:00 on all other days		45 dB(A)⁽²⁾
23:00 – 07:00 of the next day		30 dB(A)⁽²⁾

Notes:

(1) Between 07:00 and 19:00, construction noise limit for school during normal term time is 70 dB(A) and 65 dB(A) during examination period.

(2) The ASR of identified noise sensitive receivers is “A”, which is a rural area that is not affected by the in Influencing Factors (Ifs). The limit levels are stipulated in the Technical Memorandum on Noise from Construction Work in Designated Areas.

3.4 Results and Observations

3.4.1 The detailed monitoring results during the reporting period are reported in the monthly EM&A Reports. The graphical presentation of noise monitoring at the monitoring stations are shown in Appendix 3.2.

3.4.2 No Action or Limit levels exceedance was recorded in the reporting period.

4 Ecology

4.1 Freshwater Crab

4.1.1 With reference to the approved EIA Report (Register No.: AEIAR-229/2021), two freshwater crab species of conservation importance were recorded within the work sites during the ecological baseline survey. Somanniathelphusa zanklon was recorded at Lin Fa Tei and Ha Che, while Cryptopotamon anacoluthon was recorded in the upstream area at Ha Che. Both species are endemic to Hong Kong and considered to be “Endangered” and “Vulnerable” by the IUCN respectively (IUCN 2023). The construction activities of the project will disturb their natural habitats and potentially causing a direct loss of these two species due to their limited mobility.

Post-translocation Monitoring

4.1.2 According to Section 5.2.5 of the approved Updated EM&A Manual for the Project, monthly post-translocation monitoring shall be conducted for at least 12 months after pre-construction surveys to monitor their establishment.

4.1.3 During the monitoring, active visual search by hand netting and kick sampling for aquatic fauna species would be performed at the respective receptor sites. Potential micro-habitats and hiding spaces that is favoured by the crabs such as rocks, organic debris, leaf litter, and riparian vegetation etc., will also be overturned or raked.

4.1.4 Upon discovery of any marked individuals from the pre-construction survey, date and time of capture, size and health condition of the individual will also be recorded once again.

4.1.5 The practice of mark and recapture of the translocated population of S. zanklon and C. anacoluthon at the receptor site can then be used to estimate population size, as well as inform the health and survival status of the translocated population.

4.1.6 Post-translocation Monitoring was carried out in the reporting period. The monitoring results are reported in the monthly EM&A Reports prepared for this Contract.

4.1.7 None of the translocated individuals from the pre-construction survey was found in the upper and lower receptor sites of Ha Che or the receptor site of Lin Fa Tei during the reporting period.

4.1.8 However, 1 new individual of C. anacoluthon without markings were captured at the Ha Che Upper receptor sites in February 2025. This individual, however, was not the translocated individual as its details (i.e., carapace, sex and species) did not match with any of the translocated individuals in the record. No new individuals were captured during the survey in March and April 2025.

4.1.9 The inability to recapture the translocated individuals could be due to the structural complexity of the habitats of both sites. Given the presence of many rocks and riffles at the Upper Ha Che receptor site, together with large and deep pools in the Lower Ha Che receptor site, these receptor sites provide excellent refuge and protection for the crabs.

5 Waste Management

5.1.1 Waste generated from the Project include inert construction and demolition (C&D) materials and non-inert C&D wastes in the reporting period. The amount of waste generated by the construction works of the Project during the reporting period are shown in Appendix 5.1.

5.1.2 Sorting of construction and demolition (C&D) materials was carried out on site. Sufficient numbers of receptacles were provided for general refuse collection and sorting. Excavated inert C&D materials were reused to minimize the disposal of C&D waste to public fill.

5.1.3 The Contractor is advised to minimize the wastes generated through recycling or reusing. All applicable mitigation measures stipulated in the approved Updated EM&A Manual and waste management plans will be fully implemented.

6 Land Contamination

6.1.1 With reference to results of land contamination assessment included in the approved EIA Report (Register No.: AEIAR-229/2021), all identified sites with potential contamination are located outside the work area of the Project and no potential contamination arising from the proposed drainage improvement works is anticipated. Therefore, no land contamination issue is anticipated for this Project.

6.1.2 Mitigation measures listed in Appendix 1.3 should be adopted if any suspended contamination encountered during construction.

6.1.3 No suspected on-site contamination was observed or reported by the Contractor in the reporting period.

7 Landscape and Visual

7.1 Audit Requirements

7.1.1 According to the approved Updated EM&A Manual, site audits should be undertaken every week during the construction phase to check that the proposed landscape and visual mitigation measures are properly implemented and maintained as per their intended objectives. Mitigation measures recommended in the EIA Report as the audit requirements including, preservation of existing vegetation, transplanting of affected trees, compensatory tree planting, control of night-time lighting glare, erection of decorative screen hoarding and management of construction activities and facilities are summarized in Appendix 1.3.

7.2 Results and Observations

7.2.1 To monitor and audit the implementation of landscape and visual mitigation measures, 13 weekly landscape and visual site audits were carried out in the reporting period. No deficiency in the mitigation measures on landscape and visual was observed during the reporting period.

8 Cultural Heritage

8.1 Archaeology

8.1.1 According to the assessment included in the approved EIA report (Register No.: AEIAR-229/2021) the proposed drainage works in the Lin Fa Tei area are located immediately adjacent to existing river course on mainly Pleistocene terraced alluvium and the western end of the alignment on Holocene alluvium between Lin Fa Tei Site of Archaeological Interest (SAI) and Shui Lau Tin SAI. The proposed works are partially located within Lin Fa Tei SAI. Previous investigations within SAI have shown both in situ and secondary deposit and with potential for wooden features near the stream bed. As per the recommendation from EIA report, Archaeological Survey shall be conducted prior to the construction works, the concerned area is marked in Figure 8.1.

8.1.2 A qualified archaeologist shall be engaged and apply for a licence under the Antiquities and Monuments Ordinance (Cap. 53) to conduct the Archaeological Survey prior to the construction phase. The scope and methodology of the Archaeological Survey shall be agreed with Antiquities and Monuments Office (AMO) prior to implementation. Tentatively and subject to agreement with AMO, a fieldscan, where possible, twenty auger tests and four 5 by 1m narrow trenches are proposed to further assess the archaeological potential of the area. If significant remains are uncovered, AMO should be notified and potential need for mitigation and/ or an appropriate way forward should be agreed by AMO and relevant parties.

8.1.3 For remaining drainage work areas (outside the area identified for Archaeological Survey) deemed to have limited (near Kam Sheung Road) to minimal (remainder of Works Areas) archaeological potential, AMO shall be informed immediately if antiquities or supposed antiquities are discovered during construction works for the proposed drainage improvement works for ascertaining required remedial works.

8.1.4 The licence application for archaeological survey works at Lin Fa Tei, Yuen Long was approved by the AMO on 28 June 2024. The Archaeological Survey at Lin Fa Tei was carried out from 16 to 28 October 2024. During this period, the qualified Archaeologist has excavated five test trenches (5m x 1.2m each in size) coded TT1 to TT5 respectively and executed 20 auger tests coded AH1 to AH20 respectively.

8.1.5 Generally, the fill deposit at the top of the excavated area is modern and formed in recent years; the sludge deposits underneath contain no archaeological remains whatsoever.

8.1.6 Therefore, it can be concluded that there is no archaeological potential in the Licence Area, and the construction works of the Project will not cause any adverse impact to archaeological heritage in this part of the Lin Fa Tei Site of Archaeological Interest. The completion brief of archaeological survey was submitted to AMO for review on 30 October 2024. Draft Report on the Archaeological Survey at Lin Fa Tei were submitted to the AMO on 19 November 2024. Comments on the draft Report from the AMO were issued on 10 March 2025. The Report was revised and submitted to the AMO for further review on 21 March 2025. No further comment was received from the AMO up to the end of the reporting period.

8.2 Built Heritage

8.2.1 According to the approved Updated EM&A manual, mitigation measures that should be implemented during the construction phase for graded historic buildings are presented in Table 8.1.

8.2.2 Condition surveys were carried out by qualified structural engineer for Lee Tat Bridge, Lan Fong Study Hall and St John’s Chapel prior to construction works. The Pre-construction Condition Survey Report were submitted to the EPD on 22 December 2023 under Condition 2.10 of the EP.

8.2.3 Due to the distance between the works area at Ha Che and the Lan Fong Study Hall exceeded 30m radial distance during the reporting period, no vibration monitoring was undertaken. Settlement and tilting monitoring at Lan Fong Study Hall at Ha Che has been carried out during the reporting period (excluded public holiday). The distance between the north works area at Ha Che and the Lan Fong Study Hall is around 395.34m. While the distance between the south works area at Ha Che and the Lan Fong Study Hall is around 63.76m. The layout plan showing distance between the works area at Ha Che and the Lan Fong Study Hall is presented in Figure 8.2. The monitoring locations of Lan Fong Study Hall at Ha Che is presented are Figure 8.3. No exceedance for relevant monitoring was recorded during the reporting period.

8.2.4 Settlement, tilting and vibration monitoring at St. John’s Chapel near Tai Wo were carried out in February and March 2025. As no construction work was carried out at Tai Wo in April 2025, no structural monitoring was conducted at St. John’s Chapel in April 2025. The monitoring locations of St. John’s Chapel near Tai Wo are presented in Figure 8.4. No exceedance for relevant monitoring was recorded during the reporting period.

8.2.5 No monitoring has been carried out at Lee Tat Bridge at Lin Fa Tei as the works areas are more than 500 m away.

8.2.6 Monitoring data are submitted to the AMO on quarterly basis.

8.2.7 No monitoring exceedance was recorded in the reporting period.

Table 8.1 Mitigation Measures for Impacted Graded Historic Buildings

Graded Historic Buildings	Mitigation Measures
Lee Tat Bridge, Shui Tsan Tin (Grade 3)	§ A condition survey should be carried out in advance of works and after completion of works by qualified building surveyor or structural engineer. The Condition Survey Report should contain descriptions of the structure, identification of fragile elements, an appraisal of the condition and working methods for any proposed monitoring and precautionary measures that are or were recommended with aid of photo records. The condition survey report must be submitted to the AMO for comment before construction activities commence and after the works have been completed. The contractor should implement the approved monitoring and precautionary measures. § Vibration, settlement and tilting monitoring should be undertaken during the construction works to ensure that safe levels of vibration are not exceeded. An Alert, Alarm and Action (AAA) vibration limit set at 5 / 6 / 7.5 mm/s for Grade 3 historic buildings, settlement limit set at 6/ 8/ 10mm, and tilting limit set at 1/2000; 1/1500; 1/1000 should be adopted. Monitoring proposal, including checkpoint locations, installation details, response actions for each of the AAA levels and frequency of monitoring should be submitted for AMO's consideration. Installation of monitoring checkpoints shall be carried out in great care and adequate protection shall be provided so as to avoid unnecessary disturbance/ damage to the historic fabrics. Photo records of monitoring checkpoints shall be submitted upon installation for AMO's records. Monitoring records should be submitted to AMO on regular basis and alert AMO should the monitoring reach AAA levels.
Lan Fong Study Hall, Chuk Hang (Grade 3)
St John’s Chapel, Cheung Po (Grade 2)

9 Environmental Site Inspection and Audit

9.1 Implementation Status of Environmental Mitigation Measures

9.1.1 Site audits were carried out by ET on weekly basis at least once per week to monitor the implementation of proper environmental management practices and mitigation measures in the Project site.

9.1.2 Total 13 site inspections were carried out during the reporting period. No outstanding issues were reported during the reporting period. Details of observations recorded during the site inspections are presented in Table 9.1.

Table 9.1 Site Observations

Date	Environmental Observations	Follow-up Status
5 Feb 2025	Observation(s) and Recommendation(s) Ha Che: 1. The Contractor was reminded to place the updated CNP on site.	Ha Che: 1. The updated CNP has been displayed on site by the contractor.
12 Feb 2025	Observation(s) and Recommendation(s) Lin Fa Tei: 1. The Contractor was reminded to direct waterflow to the wastewater treatment system before discharge especially during rainy day.	Lin Fa Tei: 1. The water flow was redirected to the wastewater treatment system before discharge by the contractor.
19 Feb 2025	Observation(s) and Recommendation(s) Nil	Nil
26 Feb 2025	Observation(s) and Recommendation(s) Nil	Nil
5 Mar 2025	Observation(s) and Recommendation(s) Sung Shan New Village: 1. Waste near the geotextile should be removed regularly.	Sung Shan New Village: 1. Waste near the geotextile have been removed by the contractor.
12 Mar 2025	Observation(s) and Recommendation(s) Nil	Nil
19 Mar 2025	Observation(s) and Recommendation(s) Nil	Nil
26 Mar 2025	Observation(s) and Recommendation(s) Ha Che: 1. Chemical should probably store.	Ha Che: 1. Chemical has been properly stored by the contractor.
2 April 2025	Observation(s) and Recommendation(s) Nil	Nil
9 April 2025	Observation(s) and Recommendation(s) Ha Che: 1. Environmental permit should be displayed on site.	Ha Che: 1. Environmental Permit has been displayed properly on site.
16 April 2025	Observation(s) and Recommendation(s) Nil	Nil
23 April 2025	Observation(s) and Recommendation(s) Sung Shan New Village: 1. Impervious sheeting should be provided for placing the breaker to prevent land contamination on site.	Sung Shan New Village: 1. The breaker has been covered by impervious sheeting to prevent land contamination on site.
30 April 2025	Observation(s) and Recommendation(s) Sung Shan New Village: 1. The Contractor should regularly maintain the condition of geotextile and remove waste nearby.	Sung Shan New Village: 1. The Contractor has properly maintained the condition of geotextile and remove waste nearby.

Date

Environmental Observations

Follow-up Status

5 Feb 2025