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Report title

Quarterly Environmental Monitoring and Audit (EM&A) Report – November 2024 to January 2025

Document code

QEM&A-04

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

2025-02-12

Draft

Jason Man

F. C. Tsang

 

Kevin Li

1

2025-02-25

Frist Version

Jason Man

F. C. Tsang

 

Kevin Li

2

2025-03-04

Second Version

Jason Man

F. C. Tsang

 

Kevin Li

 

 

 

 

 

 

 

Current revision

2

 

 

Approval

Author signature

 

 

Certified by

Name

Jason Man

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. 8

2.6     Results and Observations. 8

2.7     Quarterly Assessment of Construction Impacts on Suspended Solids at the Project Site. 8

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. 15

10.3      Summary of Environmental Complaint. 15

10.4      Summary of Environmental Summon and Successful Prosecution. 16

11     Conclusions and Recommendations. 17

11.1      Conclusion. 17

11.2      Comments/ Recommendations. 18

 

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 1.1 General Site Location Plan

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

                  

Tables

Table A1 Summary of Exceedance Records of Water Quality Monitoring

Table 1.1 Parties Involved in Project Organisation

Table 2.1 Summary of Impact Water Quality Monitoring Stations

Table 2.2 Parameters measured in the Impact Water Quality Monitoring

Table 2.3 Action and Limit Levels for Water Quality

Table 2.4 Action and Limit Levels of Water Quality

Table 2.5 Summary of Exceedance Records of Water Quality Monitoring

Table 3.1 Noise Monitoring Stations during Construction Phase

Table 3.2 Construction Noise Monitoring Parameter, Frequency and Duration

Table 3.3 Action and Limit Levels for Construction Noise Monitoring

Table 8.1 Mitigation Measures for Impacted Graded Historic Buildings

Table 9.1 Site Observations

Table 10.1 Summary of Exceedance Records of Water Quality Monitoring

 

 

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 4th 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 November 2024 to 31 January 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 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

§  Breaking Ground

§  Temporary Drainage Diversion; and

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

§  Sheet pilling & Backfilling and Compaction

Sung Shan New Village

§  Site Clearance

§  Breaking Ground.

§  Temporary Drainage Diversion; and

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

§  Sheet pilling & Backfilling and Compaction

Tai Wo

§  No construction activities (from 1 November to 15 December 2024)

§  Site Clearance

Breaches of Environmental Quality Performance Limits (AL levels)

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

AL

LL

AL

LL

Dissolved Oxygen (DO)

0

0

0

0

0

0

Turbidity

0

0

0

0

0

0

Suspended Solids (SS)

0

0

0

0

0

0

 

A6.     No Action Level or Limit Level exceedance was recorded for water quality monitoring during the reporting period.

Noise

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

Complaint Log

A8.     One environmental complaint regarding air quality and one complaint regarding water quality were received during the reporting period. The relevant investigations are conducting by the related parties. The investigation results will be presented when the investigation has been completed.

Notification of Summons and Successful Prosecutions

A9.     No notification of summons or successful prosecutions was received in the reporting period.

Reporting Changes

A10.  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. Due to no construction activities conducted at Tai Wo from 1 November 2024 to 15 December 2024, no impact noise monitoring, impact water quality monitoring and weekly site inspection at Tai Wo was carried out during the above period. Impact noise monitoring, impact water quality monitoring and weekly site inspection at Tai Wo were resumed starting from 16 December 2024.


 

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 4th Quarterly EM&A Report summarizing the key findings of the construction phase EM&A programme from 1 November 2024 to 31 January 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.

A diagram of a company's work flow

Description automatically generated

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

§  Breaking Ground

§  Temporary Drainage Diversion; and

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

§  Sheet pilling & Backfilling and Compaction

Sung Shan New Village

§  Site Clearance

§  Breaking Ground.

§  Temporary Drainage Diversion; and

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

§  Sheet pilling & Backfilling and Compaction

Tai Wo

§  No construction activities (from 1 November to 15 December 2024)

§  Site Clearance

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 November to 15 December 2024 and conducted at 10 monitoring stations from 16 December 2024 to 31 January 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

Easting

Northing

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

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

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. Due to no construction activities conducted at Tai Wo from 1 November 2024 to 15 December 2024, no impact water quality monitoring at Tai Wo was carried out during the above period. Impact water quality monitoring at Tai Wo were resumed starting from 16 December 2024.

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)

Before 2 Dec 2024:

3 days in a week;

 

After 1 Dec 2024:

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

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.

2.3.2        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

Notes:

(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        No Action or Limit Level exceedances was recorded during the reporting period. 

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

AL

LL

AL

LL

Dissolved Oxygen

0

0

0

0

0

0

Turbidity

0

0

0

0

0

0

Suspended Solids

0

0

0

0

0

0

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

3.5

4.8

6.2

N

N

C2 (Control Point)

5.7

3.2

4.2

Y

N/A

C3A (Control Point)

4.9

2.2

2.9

Y

N/A

C4 (Control Point)

10.4

10.7

13.9

N

N/A

C5

7.0

5.2

6.8

Y

Y

C6 (Control Point)

17.2

3.7

4.8

Y

N/A

C7A (Control Point)

13.9

6.7

8.7

Y

N/A

C8

4.1

4.0

5.2

N

N

C9 (Control Point)

4.8

5.9

7.7

N

N/A

C10

3.2

8.5

11.1

N

N

Notes:

(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) (3.5 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) (7.0 mg/L) is higher than 1.3 times of the ambient mean (6.8 mg/L). Although there is no Action Level and Limit Level exceedance during the reporting period, the proposed mitigation measures for control of water quality impact at Tai Wo were properly implemented during the reporting period. These include the silt removal facilities with the discharge license under WPCO provided at Tai Wo to remove silt particles from runoff to meet the requirements of the TM standards under WPCO. The silt removal facilities were maintained and cleaned regularly to ensure the proper function. Deposited silt and grit were removed regularly and disposed of by spreading evenly over stable, vegetated areas. Earthwork surfaces were well compacted and the subsequent permanent work or surface protection was carried out immediately after the final surfaces were formed. The exposed slope surfaces and open stockpiles of construction materials on site were covered by tarpaulin to prevent the washing away of construction materials, soil, silt or debris into any drainage system. Based on above observation during the observation of the weekly site inspections, the proposed mitigation measures for control of water quality impact at Tai Wo were considered effective and efficient in pollution control during the reporting period. The contractor has been reminded that the mitigation measures for control of water quality impact at Tai Wo should continue to be maintained in good effectiveness. The detailed recommended mitigation measures are presented in Appendix 1.3.

 

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

2.7.4        The quarterly mean of SS at Monitoring Location C8 (Impact Point) (4.1 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) (3.2 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. Due to no construction activities conducted at Tai Wo from 1 November 2024 to 15 December 2024, no impact noise monitoring at Tai Wo was carried out during the above period. Impact noise monitoring at Tai Wo was resumed starting from 16 December 2024.

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 (Leq).  Leq(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

Leq(30mins) (as a logarithmic average of 6 consecutive Leq(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, 2 new individuals of C. anacoluthon without markings were captured at the Ha Che Upper and Ha Che Lower receptor sites in November 2024. These individuals, however, were not the translocated individual as their details (i.e., carapace, sex and species) did not match with any of the translocated individuals in the record.

4.1.9        In addition, 3 new individuals of C. anacoluthon without markings were captured at the Ha Che Upper and Ha Che Lower receptor sites in December 2024. These individuals, however, were not the translocated individual as their details (i.e., carapace, sex and species) did not match with any of the translocated individuals in the record.

4.1.10     Moreover, 2 new individuals of C. anacoluthon without markings were captured at the Ha Che Upper receptor sites in January 2025. These individuals, however, were not the translocated individual as their details (i.e., carapace, sex and species) did not match with any of the translocated individuals in the record.


 

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. No 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. No exceedance for relevant monitoring was recorded during the reporting period. No monitoring was carried out at St. John’s Chapel near Tai Wo as no construction works were carried out at this district since April 2024.  No monitoring has been carried out at Lee Tat Bridge at Lin Fa Tei as the works areas are more than 500 m away.  Monitoring data is submitted to the AMO on quarterly basis.


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

6 Nov 2024

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

13 Nov 2024

Observation(s) and Recommendation(s)

 

Lin Fa Tei:

1.      Geotextiles should be maintained in good condition and place to the right position.

2.      Wastewater should be direct to the wet sep ad the wet sep should be moved to the front to discharge.

 

 

Lin Fa Tei:

1.      Geotextiles was maintained in good condition and placed in the right position.

2.      Wastewater was directed to the Wet Sep for treatment and was discharged downstream of our work area.

20 Nov 2024

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

27 Nov 2024

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

4 Dec 2024

Observation(s) and Recommendation(s)

 

1.      Nil

 

 

1.      Nil

11 Dec 2024

Observation(s) and Recommendation(s)

 

Ha Che:

1.      The contractor was reminded to display the environmental permit at an appropriate location (e.g. site entrance) instead of the area within the site.

 

 

Ha Che:

1.      The environmental permit was displayed at an appropriate location by the contractor.

19 Dec 2024

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

27 Dec 2024

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

31 Dec 2024

Observation(s) and Recommendation(s)

 

Ha Che:

1.      The decolorized NRMM label should be replaced with a proper label. (BH16)

 

 

Ha Che:

1.      The proper NRMM label was attached by the contractor. (BH16)

8 Jan 2025

Observation(s) and Recommendation(s)

 

Sung Shan New Village:

1.      The Contractor was reminded to direct the effluent to sedimentation tank for treatment before discharge.

 

 

Sung Shan New Village:

1.      The effluent was direct to sedimentation tank for treatment before discharge.

15 Jan 2025

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

22 Jan 2025

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

28 Jan 2025

Observation(s) and Recommendation(s)

 

Nil

 

 

Nil

9.1.3        According to the EIA Study Report, Environmental Permit, contract documents and approved Updated EM&A Manual, the mitigation measures detailed in the documents should be implemented as much as practical during the reporting period. An updated Implementation Status of Environmental Mitigation Measures (EMIS) is provided in Appendix 1.3.


 

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

10.1   Summary of Exceedance

Water Quality Monitoring

10.1.1     The summary of exceedance records of water quality monitoring during the reporting period is summarized in Table 10.1.

Table 10.1 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

AL

LL

AL

LL

Dissolved Oxygen

0

0

0

0

0

0

Turbidity

0

0

0

0

0

0

Suspended Solids

0

0

0

0

0

0

10.1.2     No Action Level or Limit Level exceedance was recorded during the reporting period.

Noise Monitoring

10.1.3     No Action Level or Limit Level exceedance was recorded during the reporting period.

10.2   Summary of Environmental Non-Compliance

10.2.1     No environmental non-compliance was recorded in the reporting period.

10.3   Summary of Environmental Complaint

10.3.1     One environmental complaint regarding air quality and one complaint regarding water quality were received during the reporting period. The relevant investigations are conducting by the related parties. The investigation results will be presented when the investigation has been completed.

10.3.2     The Cumulative Complaint Log is presented in Appendix 10.1.

10.4   Summary of Environmental Summon and Successful Prosecution

10.4.1     There was no successful environmental prosecution or notification of summons received since the Project commencement. The Cumulative Log for environmental summon and successful prosecution is presented in Appendix 10.1.


 

11        Conclusions and Recommendations

11.1   Conclusion

11.1.1     This 4th Quarterly EM&A Report presents the EM&A works during the reporting period from 1 November 2024 to 31 January 2025 in accordance with the approved Updated EM&A Manual.

11.1.2     Water Quality Monitoring was conducted during the reporting period. No Action or Limit Level exceedance was recorded during the reporting period.

11.1.3     Construction noise monitoring was carried out during the reporting period. No Action Level or Limit Level exceedance was recorded for construction noise monitoring in the reporting period.

11.1.4     Post-translocation monitoring was conducted during the reporting period. 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. However, 2 new individuals of C. anacoluthon without markings were captured at the Ha Che Upper and Ha Che Lower receptor sites in November 2024. 3 new individuals of C. anacoluthon without markings were captured at the Ha Che Upper and Ha Che Lower receptor sites in December 2024. 2 new individuals of C. anacoluthon without markings were captured at the Ha Che Upper receptor sites in January 2025. These individuals, however, were not the translocated individual as their details (i.e., carapace, sex and species) did not match with any of the translocated individuals in the record from November 2024 to January 2025.

11.1.5     Total 13 environmental site inspections and 13 landscape and visual site audits were carried out in the reporting period. Recommendations on mitigation measures were given to the Contractor for remediating the deficiencies identified during the site inspections.

11.1.6     One environmental complaint regarding air quality and one complaint regarding water quality were received during the reporting period. The relevant investigations are conducting by the related parties. The investigation results will be presented when the investigation has been completed.

11.1.7     No notification of summons and successful prosecutions were recorded in the reporting period.

11.1.8     The EM&A methodology has been effective in monitoring the environmental impacts of the Project and the effectiveness of the mitigation measures. The data collected were useful in determining whether the Project had caused unacceptable impacts on the sensitive receivers. Analysis of all EM&A data collected throughout the baseline and the impact monitoring periods demonstrated the environmental acceptability of the Project.

11.2   Comments/ Recommendations

11.2.1     The key environmental mitigation measures for the Project in the coming reporting period expected to be associated with the construction activities include:

Noise

 

§  Only well-maintained plant should be operated on-site, and plant should be maintained regularly during the construction programme; and

§  Quality Powered Mechanical Equipment (QPME) should be adopted as far as possible.

Water Quality

 

§  No effluent discharge would be allowed before acquired the effluent discharge license;

§  Surface run-off from construction sites should be discharged into dedicated discharge point via adequately designed sand/ silt removal facilities;

§  Channels/ earth bunds/ sandbags barriers should be provided on site to properly direct stormwater to silt removal facilities;

§  Silt removal facilities, channels and manholes should be maintained, and the deposited silt and grit should be removed regularly;

§  Open stockpiles of construction materials on sites should be covered with tarpaulin or similar fabric during rainstorms; and

§  Perimeter channels should be provided on site boundaries where necessary to intercept stormwater run-off from outside the site so that it will not wash across the site.

Waste Management

 

§  Provision of sufficient waste disposal points and regular collection of waste;

§  Regular cleaning and maintenance programme for drainage system; and

§  Chemical containers shall be stored with drip tray underneath.

Ecology

 

§  Minimize loss of habitats and associated wildlife; and

§  Using directional lighting to prevent excessive light spill into adjacent natural habitat and disturbance to nocturnal fauna.

Landscape and Visual

 

§  Construction activities shall be carefully designed to minimize impact on existing retained trees; and

§  Adequate tree protection measures shall be provided for the trees to be retained on site.

11.2.2     The proposed mitigation measures were properly implemented and were considered effective and efficient in pollution control.