Contract No. CM 04/2024 –

Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works – Environmental Team Services (2025 - 2027)

Monthly Environmental Monitoring and Audit Report for:

April 2025

Revision 1

 

Certified By:

 

 

 


______________

Ting Po Chung, Ivan

Environmental Team Leader

Report Date: 16 May 2025

 

 


 


Content:

 

1.         Introduction. 1

1.1       Project Background. 1

1.2       Environmental Monitoring & Audit Programme. 1

1.3       Monthly Environmental Monitoring & Audit Report 2

2.         Basic project Information and Environmental Status. 4

2.1       Basic Project Information. 4

2.2       Construction Programme. 4

2.3       Works undertaken during the Reporting Month. 5

2.4       Drawing Showing the Project Area, Environmental Sensitive Receivers and Monitoring Locations. 5

3.         Implementation Status. 6

3.1       Advice on the Implementation Status of Environmental Protection and Pollution Control/Mitigation Measures. 6

3.2       Environmental Mitigation Measures. 6

3.3       Environmental Monitoring Requirements and Contractual Requirements. 6

3.4       Site Inspection and Audit Reports. 7

4.         Noise Monitoring. 9

4.1       Monitoring Methodology. 9

4.2       Monitoring Stations. 10

4.3       Monitoring Date, Time, Frequency and Duration. 11

4.4       Noise Monitoring Results. 11

5.         Water Quality Monitoring. 12

5.1       Monitoring Methodology. 12

5.2       Monitoring Stations. 13

5.3       Monitoring Date, Time, Frequency and Duration. 14

5.4       Monitoring Results. 15

6.         Ecology. 17

6.1       Monitoring Methodology. 17

6.2       Parameters Monitored. 17

6.3       Monitoring Location. 17

6.4       Monitoring Date, Time, Frequency and Duration. 17

6.5       Monitoring Results. 17

7.         Waste Management 18

8.         Complaints, Notification of Summons and Prosecution. 19

9.         Future Key Issues. 21

10.       Conclusion. 22

10.1     Noise Monitoring. 22

10.2     Water Quality Monitoring. 22

10.3     Ecological Impact Monitoring. 22

10.4     Review of the Reasons for and the Implications of Non-compliance. 22

10.5     Summary of Action Taken in the Event of and Follow-Up on Non-Compliance. 22

 

Tables:

 

Table 2.1:     Contact Details of Key Personnel

Table 3.1:     Summary of Submission Status under EP-538/2017

Table 3.2:     Summary of the Current Status on Licences and/or Permits on Environmental Protection Pertinent to The Project

Table 3.3:     Summary of Environmental Inspections

Table 4.1:     Noise Monitoring Equipment

Table 4.2:     Noise Monitoring Station

Table 5.1:     Water Quality Monitoring Equipment

Table 5.2:     Marine Water Quality Stations for Water Quality Monitoring

Table 5.3:     Action and Limit Levels of Water Quality

Table 7.1:     Summary of Quantities of Waste Material

Table 8.1:     Cumulative Statistics on Complaints

Table 8.2:     Summary of Complaints

Table 8.3:     Cumulative Statistics on Successful Prosecutions

Table 9.1:     Construction Activities and Recommended Mitigation Measures in Coming Reporting 3 Months

Table 10.1:        Summary of Ecological Impact Monitoring

 

Figures:

 

Figure 2.1        Master Layout Plan

Figure 2.2        Contract Layout Plan

Figure 2.3        Locations of Noise Monitoring Station

Figure 2.4        Locations of Water Quality Monitoring Stations

Figure 5.1        Typical Details of Proposed Silt Curtain

Figure 6.1        Mark up Figure 5.4i extracted from approved EIA Report (AEIAR-210/2017)

Figure 6.2        Location Plan for Temporary Holding Nursery

 

Appendices:

 

Appendix 4.1    Calibration Certificates for Noise Meter and Acoustic Calibrator

Appendix 4.2    Impact Monitoring Schedule for Construction Phase Noise Monitoring for the Reporting Month and Next Month

Appendix 4.3    Noise Monitoring Results and Graphical Presentations

Appendix 5.1    Calibration Certificates of the Water Quality Monitoring Equipment

Appendix 5.2    Impact Monitoring Schedule for Construction Phase Water Quality Monitoring for the Reporting Month and Next Month

Appendix 5.3    Marine Water Quality Monitoring Results and Graphical Presentations

Appendix 7.1    Monthly Summary Waste Flow Table

Appendix 9.1    3 Months Rolling Programme

 


Executive Summary

 

This Monthly Environmental Monitoring and Audit (“EM&A”) Report summarise project monitoring and auditing data, with full interpretation illustrating the acceptability or otherwise of any environmental impacts and identification or assessment of the implementation status of agreed mitigation measures, including monitoring results and findings of the EM&A Programme, along with findings recorded during the site Inspections and audits, reports of Complaints, Notifications of Summons and Successful Prosecutions, and other necessary observations obtained within this reporting month of April 2025.

In the reporting month, the principal work activities conducted are as follow:

·         Excavation, sewer laying, construction of manhole at Pui O Lo Uk Tsuen, South Lantau Road, Chi Ma Wan Road;

·         Excavation and site formation at San Shek Wan Sewerage Treatment Works (“SSWSTW”);

·         Trenchless drilling works at Chi Ma Wan Road;

·         Excavation and Excavation and Lateral Support (”ELS”) work at Pui O Sewage Pumping Station (“POSPS”);

·         Superstructure Reinforced Concrete (“RC”) works at SSWSTW;

·         Retaining wall construction at SSWSTW;

·         Dredging and diffuser construction at SSWSTW; and

·         Electrical and Mechanical (“E&M”) Installation at POSPS.

Noise Monitoring

Noise Monitoring has been conducted at 8 of the designated monitoring locations (N12a, N12b, N13, N14, N15b, N16a, N16b, and N17) where construction works has been conducted nearby during the reporting month.

No action or limit level exceedance was recorded in construction noise level in this reporting period.

Water Quality Monitoring

Marine Water Monitoring has been conducted at 9 designated monitoring locations during the reporting month.

No action or limit level exceedances were recorded within the reporting month.

Ecological Impact Monitoring

Transplanting of the trees of Aquilaris sinensis was completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.

As per latest version of PTP, 4 tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery at Kam Tin and eventually be transplanted to Pui O Pumping Station.

The weekly site audit was carried out by ET include checking whether good site practices are being properly implemented by the Contractor.

The extent of the work site boundaries was checked by the ET during the weekly site audit.

Complaints, Notification of Summons and Prosecution

No environmental complaint was recorded in the reporting month.

No notification of summons and successful prosecution regarding construction works were recorded in the reporting month.

Reporting Changes

There are no reporting changes in the reporting month.

Future Key Issues

In coming reporting 3 months, the scheduled construction activities are listed as follows:

·         Excavation, sewer laying, construction of manhole at Pui O Lo Uk Tsuen, South Lantau Road, Chi Ma Wan Road;

·         Excavation and site formation at SSWSTW;

·         Trenchless drilling works at Chi Ma Wan Road;

·         Excavation and ELS work at POSPS;

·         Superstructure RC works at SSWSTW;

·         Retaining wall construction at SSWSTW;

·         Dredging and diffuser construction at SSWSTW; and

·         E&M Installation at POSPS.

Key construction activities for the next three months with the recommended mitigation measures to be implemented are presented as follows:

 

Key Construction Works

Recommended Mitigation Measures

·         Excavation, sewer laying, construction of manhole at Pui O Lo Uk Tsuen, South Lantau Road, Chi Ma Wan Road

·         Excavation and site formation at SSWSTW

·         Trenchless drilling works at Chi Ma Wan Road

·         Excavation and ELS work at POSPS

·         Superstructure RC works at SSWSTW

·         Retaining wall construction at SSWSTW

·         Dredging and diffuser construction at SSWSTW

·         E&M Installation at POSPS

·         Implementation of noise pollution control in accordance with Construction Noise Mitigation Plan;

·         Dust control during dust generating works;

·         Silt curtain should be maintained in good condition prior to and during dredging and related marine works;

·         Adopt surface drainage and sediment control facilities for sewage installation in village and public roads;

·         Adopt temporary drainage and sediment control facilities on Site;

·         Vehicle wheel-washing and body washing facilities should be provided at the site entrance;

·         Regular water spraying on excavation works for dust control; and

·         Proper waste handling, recycling and storage.

 


1.                 Introduction

1.1              Project Background

1.1.1          The Environmental Protection Department (“EPD”) completed the Outlying Islands Sewerage Master Plan (“SMP”) Study in 1994 and drew up a SMP for Lantau Island and other outlying islands. The proposed sewerage works of the SMP were divided into 2 stages. The Stage 2 Works of the SMP were subsequently reviewed by EPD under the Outlying Islands Sewerage Master Plan Stage 2 Review (SMP Review Study) in 2001.

1.1.2          The proposed sewerage works for South Lantau were further reviewed in 2008 under the Review of Sewerage Scheme for South Lantau (Review Study). According to the Review Study, the proposed sewerage works for South Lantau would serve the unsewered areas of Shui Hau, Tong Fuk, Cheung Sha, San Shek Wan, Pui O and Ham Tin.

1.1.3          The Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works, herein referred to as “the Project”, referred to the sewerage works for South Lantau that would serve the unsewered areas of Shui Hau, Tong Fuk, Cheung Sha, San Shek Wan, Pui O and Ham Tin.

1.1.4          The Project mainly comprises of the following items:

a)  Construction of a secondary sewage treatment works (“STW”) at San Shek Wan in South Lantau;

b)  Construction of sewage pumping station (“SPS”) at Pui O, San Shek Wan, Cheung Sha, Cheung Fu Street, Shui Hau and Tong Fuk;

c)  Construction of about 1.4km of twin submarine outfalls with a diameter of 350mm for the disposal of treated effluent from the STW at San Shek Wan;

d)  Construction of about 10.1km of gravity sewers with diameters ranging from 150mm to 375mm along South Lantau Road and Chi Ma Wan Road and at Pui O; and

e)  Construction of about 3.1km of twin rising mains with a diameter of 200mm to 250mm along South Lantau Road and Chi Ma Wan Road.

1.2              Environmental Monitoring & Audit Programme

1.2.1          An Environmental Impact Assessment (“EIA”) was subsequently prepared to review the potential environmental impact that would be due to the Project during its construction works and operational works. The EIA Report was submitted and approved on 24 April 2017, and Environmental Permit (“EP”) No. EP-538/2017 was subsequently granted on 13 July 2017.

1.2.2          Environmental Monitoring & Audit (“EM&A”) Programme is therefore implemented in accordance with the EM&A Manual under the EIA Report.

1.2.3          Umwelt Consulting Limited (“UCL”) has been appointed to work as the Environmental Team (“ET”) under EP No. EP-538/2017 to implement the Environmental Monitoring and Audit (“EM&A”) programme as stipulated in the EM&A Manual of the approved EIA Report for the Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works (Register No.: AEIAR-210/2017).

1.3              Monthly Environmental Monitoring & Audit Report

1.3.1          This Monthly EM&A Report summarise project monitoring and auditing data, with full interpretation illustrating the acceptability or otherwise of any environmental impacts and identification or assessment of the implementation status of agreed mitigation measures, including monitoring results and findings of the EM&A Programme, along with findings recorded during the site Inspections and audits, reports of Complaints, Notifications of Summons and Successful Prosecutions, and other necessary observations obtained within this reporting month of April 2025.

1.3.2          The structure of this Report is detailed as follows:

a)  Section 1 Introduction –
Details the scope and structure of the report.

b)  Section 2 Basic project Information and Environmental Status –
Summarizes project organization and key personnel contact, construction programme and works undertaken for the month. Construction programme, works undertaken during the month with illustrations, drawing showing the project area, environmental sensitive receivers and monitoring locations.

c)  Section 3 Implementation Status –
Advice on the implementation status of environmental protection and pollution control/mitigation measures, as recommended in the EIA Report and summarised in the updated implementation schedule.

d)  Section 4 Noise Monitoring –
Summarizes the monitoring results obtained in the reporting period, including monitoring methodology, name of laboratory and equipment used and calibration details, parameters monitored, monitoring locations (and depth), monitoring date, frequency, and duration, for impact noise monitoring.

e)  Section 5 Water Quality Monitoring –
Summarizes the monitoring results obtained in the reporting period, including monitoring methodology, name of laboratory and equipment used and calibration details, parameters monitored, monitoring locations (and depth), monitoring date, frequency, and duration, for impact water quality monitoring.

f)   Section 6 Ecology –
Summarizes the audit findings during the reporting month on ecological aspects.

g)  Section 7 Waste Management –
Summarizes the status of waste management, including the amount and types of waste generated, and respective treatment approach.

h)  Section 8 Report on Complaints, Notification of Summons and Successful Prosecutions –
Summarizes:

Ø Record of all complaints received (written or verbal) for each media, including locations and nature of complaints investigation, liaison and consultation undertaken, actions and follow-up procedures taken, results and summary;

Ø Record of notifications of summons and successful prosecutions for breaches of the current environmental protection/pollution control legislations, including locations and nature of the breaches, investigation, follow-up actions taken, results and summary;

Ø Review of the reasons for and the implications of non-compliance, complaints, summons and prosecutions including review of pollution sources and working procedures; and

Ø Description of the actions taken in the event of non-compliance and deficiency reporting and any follow-up procedures related to non-compliance.

i)    Section 9 Future Key Issues –
An account of the future key issues as reviewed from the works programme and work method statements.

j)    Section 10 Conclusion –
Summarises the findings conclusion drawn from the environmental monitoring and audit programme in this reporting month.

2.                 Basic project Information and Environmental Status

2.1              Basic Project Information

2.1.1          Drainage Services Department (“DSD”) is the project proponent and the permit holder of the Project. For the construction phase of the Project, Contractor(s), ET and Independent Environmental Checker (“IEC”) are appointed to manage and control environmental issues. Key personnel and contact particulars are summarized in Table 2.1.

2.1.2          Upon conclusion of Contract No: SD 15/2022 Outlying Island Sewerage Stage 2 – South Lantau Sewage Works – Environmental Team Services (2023 – 2024), the subsequent contract, Contract No. CM 04/2024 Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works – Environmental Team Services (2025-2027), has been awarded to Umwelt Consulting Limited (“UCL”) starting 1 February 2025. As such the environmental team leader (“ETL”) appointed for the Project has been updated to Mr. Ting Po Chung, Ivan since 1 February 2025. His contact details has been updated in Table 2.1.

2.1.3          There are no other reporting changes in the reporting month.

Table 2.1:    Contact Details of Key Personnel

Party

Role

Post

Name

Contact No.

Contact Fax

Drainage Services Department

The Engineer for the Contract

Engineer

Mr. KK Chan

2594 7297

3104 6426

Binnies Hong Kong Limited

Engineer’s Representative

Resident Engineer

Mr. Kevin Chan

3529 3003

-

Kwan Lee – Chun Wo Joint Venture

Contractor

Sub Agent

Mr. Daniel Chu

6737 6701

2744 6937

Environmental Supervisor

Ms. Joey Pang

6978 2876

Environmental Supervisor

Mr. Philip Wong

6908 8920

SMEC Hong Kong

IEC

IEC

Ms. Kitty Lee

3995 8140

3422 3631

Umwelt Consulting Limited

ET

ET Leader

Mr. Ivan Ting

3756 9590

3582 3310

 

2.2              Construction Programme

2.2.1          The proposed sewerage works will collect the sewage generated from the unsewered areas of Shui Hau, Tong Fuk, Cheung Sha, San Shek Wan, Pui O and Ham Tin in South Lantau (i.e. within the Project Catchment Area) and convey it to a proposed sewage treatment works at San Shek Wan for treatment and disposal into outer bay of Pui O / Chi Ma Wan via a submarine outfall.

2.2.2          The Project was divided into 3 contracts. The current contract, Contract No. DC/2020/02 - Construction of San Shek Wan Sewage Treatment Works, Associated Submarine Outfall and Pui O Sewerage Works (“the Contract”) would have the following implementations. The works site of the Contract is also given in Figure 2.1.

2.2.3          The major components of the Contract under Environmental Permit (“EP”) (EP No. EP-538/2017) comprises:

a)  Construction of a secondary sewage treatment works (“STW”) at San Shek Wan in South Lantau;

b)  Construction of a sewage pumping station (“SPS”) at Pui O, San Shek Wan, Cheung Sha and Cheung Fu Street;

c)  Construction of about 1.4km of submarine outfall with a diameter of 350mm for the disposal of treated effluent from the STW at San Shek Wan;

d)  Construction of about 10.1km of gravity sewers with diameters ranging from 150mm to 375mm along South Lantau Road and Chi Ma Wan road and at Pui O; and

e)  Construction of about 3.1km twin rising mains with a diameter of 200mm to 250mm along South Lantau Road and Chi Ma Wan Road.

2.3              Works undertaken during the Reporting Month

2.3.1          In the reporting month, the principal work activities conducted are as follow:

a)  Excavation, sewer laying, construction of manhole at Pui O Lo Uk Tsuen, South Lantau Road, Chi Ma Wan Road;

b)  Excavation and site formation at SSWSTW;

c)  Trenchless drilling works at Chi Ma Wan Road;

d)  Excavation and ELS work at POSPS;

e)  Superstructure RC works at SSWSTW;

f)   Retaining wall construction at SSWSTW;

g)  Dredging and diffuser construction at SSWSTW; and

h)  E&M Installation at POSPS.

2.3.2          The locations of the works are shown in Figure 2.2.

2.4              Drawing Showing the Project Area, Environmental Sensitive Receivers and Monitoring Locations

2.4.1          Noise and water monitoring location plans with sensitive receivers are shown in Figure 2.3 and Figure 2.4 respectively.

3.                 Implementation Status

3.1              Advice on the Implementation Status of Environmental Protection and Pollution Control/Mitigation Measures

3.1.1          Mitigation measures according to the environmental mitigation implementation schedule in Annex A of EM&A Manual were generally implemented by the Contractor. Hence, the EM&A programme was considered effective and shall be maintained.

3.2              Environmental Mitigation Measures

3.2.1          Environmental mitigation measures mentioned the EIA Report were weekly reviewed and recorded in Weekly Environmental Site Audit Checklist. Also, a summary of the current status on submissions and measures mentioned in the EP No. EP-538/2017 are shown in Table 3.1.

Table 3.1:    Summary of Submission Status under EP-538/2017

EP Condition

Submission and Revision No.

Date of Latest Submission

2.10

Waste Management Plan (Rev. 5) (electronic copy)

4 April 2022#

2.11

Submission of Preservation and/or Transplantation Plan for Plant Species of Conservation Importance (Rev. 23)

9 September 2022#

2.12

Submission of Compensatory Woodland Planting Plan (Rev. 23)

15 May 2023^

2.13

Silt Curtain Deployment Plan (Rev. 11)

1 June 2022#

2.14

Landscape Mitigation Plan

To be confirmed

2.15

Construction Noise Mitigation Plan (Rev. 20)

4 August 2022#

Note:

^    Submission was made to EPD

#    Approval from EPD was received

3.3              Environmental Monitoring Requirements and Contractual Requirements

3.3.1          A summary of the current status on licences and/or permits on environmental protection pertinent to the Project is shown in Table 3.2.

Table 3.2:    Summary of the Current Status on Licences and/or Permits on Environmental Protection Pertinent to The Project

Permits and/or Licences

Permit. No. / Account No.

Issued Date

Valid Period & Expiry Date

Status

Notification of Works Under APCO

466408

14 Apr 2021

N/A

Valid

Wastewater Discharge Licence under Water Pollution Control Ordinance

SSWSTW: WT00039636-2021

30 Dec 2021

30 Dec 2021 to
31 Dec 2026

Valid

POPS: WT00039820-2021

31 Dec 2021

31 Dec 2021 to
31 Dec 2026

Valid

SSWSTW: Gravity Sewer & Raising Main: WT00042613-2022

09 Jan 2023

09 Jan 2023 to
31 Jan 2028

Valid

Billing account under Waste Disposal Ordinance

Account No.: 7040411

05 May 2021

N/A

Valid

Registration as a Chemical Waste Producer

0000-931-K3428-01

13 May 2021

N/A

Valid

Construction Noise Permit under Noise Control Ordinance for SSWSTW

GW-RS0084-25

28 Jan 2025

09 Feb 2025 to
08 Aug 2025

Valid

Construction Noise Permit under Noise Control Ordinance for POSPS

GW-RS0310-25

26 Mar 2025

28 Mar 2025 to

26 Sep 2025

Valid

Marine Dumping Permit (Dredged Sediment Requiring Type 1 – Open Sea Disposal

EP/MD/25-024

19 Nov 2024

19 Nov 2024 to
18 May 2025

Valid

Note: Only valid permits or permits under applications within the reporting month are included.

3.4              Site Inspection and Audit Reports

3.4.1          Within this reporting month, weekly environmental site inspections were conducted on 7, 14, 23, and 28 April 2025. IEC attended the SSEMC meeting held on 23 April 2025. The ET and contractor participated in the holding nursery visit for transplanted trees on 23 April 2025.

3.4.2          No non-compliance was found during the site inspections while reminders on environmental measures were recommended. Reminders and/or Observations recorded during site inspections in this reporting month are listed in Table 3.3.

Table 3.3:    Summary of Environmental Inspections

Inspection Date

Reminder and Recommendations

Close-out Date / Status

7April 2025

Pui O Sewage Pumping Station

No Reminder and/or Observation

San Shek Wan Sewage Treatment Works

No Reminder and/or Observation

 

N/A

14 April 2025

Pui O Sewage Pumping Station

No reminder and/or observations

San Shek Wan Sewage Treatment Works

No reminder and/or observations

 

N/A

23 April 2025

Pui O Sewage Pumping Station

No reminder and/or observations

San Shek Wan Sewage Treatment Works

Reminder 1:

The contractor is reminded to cover the dust with a tarpulin or sprinkle water.

Kam Tin Nursery

Reminder 1:

The contractor is reminded to properly install the tree label.

 

Contractor has rectified the reminders on 7 May 2025

28 April 2025

Pui O Sewage Pumping Station

No Reminder and/or Observation

San Shek Wan Sewage Treatment Works

Reminder 1:

The contractor is reminded to ensure the waste are properly aggregated and placed within appropriate container for disposal and/or recycle.

 

Contractor has rectified the reminders on 7 May 2025

4.                 Noise Monitoring

4.1              Monitoring Methodology

Monitoring Procedure

4.1.1          The impact noise monitoring should be carried out at all the designated monitoring stations when there are project-related construction activities undertaken within a radius of 300m from the monitoring stations.

4.1.2          The monitoring station shall normally be at a point 1m from the exterior of the sensitive receiver’s building façade and be at a position 1.2m above the ground.

4.1.3          Façade measurements were made at the monitoring locations. For free-field measurement, a correction factor of +3dB(A) will be applied.

4.1.4          The battery condition was checked to ensure the correct functioning of the meter.

4.1.5          Parameters such as frequency weighting, the time weighting and the measurement time were set as follows:

a)  Frequency weighting: A,

b)  Time weighting: Fast,

c)  Measurement time set: continuous 5 mins

4.1.6          Prior and after to the noise measurement, the meter was checked using the acoustic calibrator for 94dB (A) at 1000 Hz. If the difference in the calibration level before and after measurement was more than ±1.0 dB (A), the measurement would be considered invalid and repeat of noise measurement would be required after recalibration or repair of the equipment.

4.1.7          Noise measurements will be made in accordance with standard acoustical principles and shall not be made in fog, rain, wind with a steady speed exceeding 5m/s or wind with gusts exceeding 10m/s. The wind speed shall be checked with a portable wind speed meter capable of measuring the wind speed in m/s.

Equipment Used for Noise Monitoring

4.1.8          Noise monitoring was performed using sound level meter at the designated monitoring locations. The sound level meters shall comply with the International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1) specifications. Acoustic calibrator shall be deployed to check the sound level meters at a known sound pressure level. Brand and model of the equipment is given in Table 4.1.

Table 4.1:    Noise Monitoring Equipment

Equipment

Brand and Model

Serial Number

Valid Until

Integrated Sound Level Meter

Rion - NL-52

01198668

13 Jan 2026

Acoustic Calibrator

Rion - NC-75

34202223

13 Jan 2026

 

4.1.9          The calibration certificates of the noise monitoring equipment are attached in Appendix 4.1.

Calibration Details

4.1.10       The microphone head of the sound level meter was cleaned with soft cloth at regular intervals.

4.1.11       The sound level meter and calibrator were calibrated at yearly intervals.

Parameters Monitored

4.1.12       The construction noise level shall be measured in terms of the A-weighted equivalent continuous sound pressure level (“Leq”). Leq(30min) should be used as the monitoring parameter. Supplementary information for data auditing, statistical results such as L10 and L90 shall also be obtained for reference.

4.1.13       For impact monitoring for construction of village sewers / rising main, noise monitoring should be undertaken on weekly basis. 1 set of Leq(30min) noise level as 6 consecutive Leq(5min) between 07:00-19:00 hours on normal weekdays has been taken.

4.2              Monitoring Stations

4.2.1          The noise monitoring stations for the Project are listed and shown in Table 4.2. Impact noise monitoring was conducted once per week at the noise monitoring stations with construction works being conducted nearby. Noise monitoring has been conducted at 8 noise monitoring stations N12a, N12b, N13, N14, N15b, N16a, N16b and N17 in the reporting month.

4.2.2          Monitoring station N17 Bui O Public School is an institutional sensitive receivers. During the reporting month, no examination was conducted, as such the construction noise criteria is 70dB(A). During examination period, which was reported to be May and June 2025, the construction noise criteria will be revised to 65dB(A) accordingly.

Table 4.2:    Noise Monitoring Station

Monitoring Station ID +

Monitoring Location

Measurement Type

Level (in terms of no. of floor)

N01a

Shui Hau Village

Free-Field

G/F

N01c

Shui Hau Village

Free-Field

G/F

N03a

Tong Fuk Village

Free-Field

G/F

N05a

Residences at Cheung Fu Street

Free-Field

G/F

N07

Government Holiday Bungalows

Free-Field

G/F

N08

Cheung Sha Ha Tsuen

Free-Field

G/F

N10

Cheung Sha Sheung Tsuen

Façade

G/F

N11b

San Shek Wan – Ming Garden

Free-Field

G/F

N12a *

Lo Uk Tsuen

Free-Field

G/F

N12b *

Lo Uk Tsuen

Free-Field

G/F

N13 *

Pui O San Wai Tsuen

Free-Field

G/F

N14 *

South Lantau Community Centre

Free-Field

G/F

N15b *

Pui O Lo Wai Tsuen

Façade

G/F

N16a *

Residences at Ham Tin

Façade

G/F

N16b *

Residences at Ham Tin

Free-Field

G/F

N17 *

Bui O Public School

Façade

R/F

NOTE:

+     Fine adjustment of noise monitoring stations at all locations was proposed as per EP Condition 3.1.

*     Measurement was conducted at the station in the reporting month.

4.3              Monitoring Date, Time, Frequency and Duration

4.3.1          For daytime construction work on normal weekdays, monitoring of Leq(30min) should be carried out at each station at 0700-1900 hours on normal weekdays at a frequency of once a week. Impact monitoring schedule can be referred to Appendix 4.2.

4.4              Noise Monitoring Results

4.4.1          Noise monitoring results measured in this reporting period are reviewed and summarized. Details of noise monitoring results and graphical presentation can be referred in Appendix 4.3.

4.4.2          No action or limit level exceedance was recorded in construction noise level in this reporting period.

5.                 Water Quality Monitoring

5.1              Monitoring Methodology

Monitoring Procedure

5.1.1          The condition near the monitoring stations shall be observed and recorded on the data log sheet.

5.1.2          Check of sensors and electrodes with certified standard solutions before each use.

5.1.3          Wet bulb calibration for a DO meter should be carried out before measurement.

5.1.4          Water depth should be recorded by detector before sampling.

5.1.5          A water sampler, consisting of a PVC or glass cylinder of not less than two litres, which can be effectively sealed with cups at both ends, will be used for water sampling. The water sampler will have a positive latching system to keep it open and prevent premature closure until released by a messenger when the sampler is at the selected water depth.

5.1.6          Transfer the collected water carefully into cleaned water bottles (2x 1000ml) provided by the laboratory at the spot for the subsequent laboratory Suspended Solid testing.

5.1.7          Parameters including Water Temperature (°C), pH (units), Salinity (ppt), DO (mg/L), DO saturation (%), and Turbidity (NTU) will be measured in-situ by the Multifunctional Meter. Water Temperature and Salinity will be recorded for reference.

5.1.8          Record the result on the data log sheet and record any special finding during / after in-situ measurement.

5.1.9          The water sample bottles will be stored in a cool box (at cooled to 4°C without being frozen), which shall be delivered to HOKLAS laboratory (ALS Technichem (HK) Pty Ltd) for further testing to determine the level of Suspended Solids (“SS”).

Name of Laboratory and Equipment Used and Calibration Details

Laboratory Measurement / Analysis

5.1.10       Analysis of suspended solids will be carried out in a HOKLAS accredited laboratory, ALS Technichem (HK) Pty Ltd.

Equipment Used

Dissolved Oxygen, pH and Temperature Measuring Equipment

5.1.11       Multifunctional Meter are used at each designated monitoring station. They are capable of measuring:

a)  a dissolved oxygen level in the range of 0-20mg/L and 0-200% saturation (Detection Limit: 0.1mg/L)

b)  a temperature of 0-45 degree Celsius (Detection Limit: 0.1 degree Celsius)

c)  turbidity level between 0-1000NTU (Detection Limit: 0.1NTU)

d)  salinity in the range of 0-40ppt (Detection Limit: 0.1ppt)

e)  pH value in range of 0.0 – 14.0 (Detection Limit: 0.1units)

5.1.12       Other monitoring equipment namely water depth meter, water current meter, dGPS positioning device, water sampler listed below were also deployed,

a)  Water depth meter (Range: 0.6 -100m, Resolution: 0.1m)

b)  Water current meter (Range: 0-360°, Detection Limit: 1mm/s)

c)  dGPS positioning device (Resolution: Horizontal: 0.25m; Vertical: 0.50m)

d)  Water sampler (Horizontal discrete type, Capacity: 2.2L)

Sampler Container and Storage

5.1.13       A water sampler, water samples for suspended solids measurement should be collected in high-density polythene bottles, packed in ice (cooled to 4°C without being frozen), and delivered to ALS Technichem (HK) Pty Ltd. as soon as possible after collection for analysis.

Water Depth Detector

5.1.14       A portable, battery-operated echo sounder shall be used for the determination of water depth at each designated monitoring station. This unit can either be handheld or affixed to the bottom of the workboat, if the same vessel is to be used throughout the monitoring programme.

Calibration Details

5.1.15       Maintenance and Calibration

a)  The responses of sensors and electrodes of the water quality monitoring equipment were cleaned and checked at regular intervals.

b)  The Multifunctional Meter was certified by a laboratory accredited under HOKLAS or any other international accreditation scheme, and subsequently re-calibrated at 3 monthly intervals.

5.1.16       Brand and model of the equipment are given in Table 5.1.

Table 5.1:    Water Quality Monitoring Equipment

Equipment

Brand and model

Series Number

Multifunctional Meter

YSI ProDSS

21G105356

21K101469

16H104233

 

5.1.17       Calibration certificates of the water quality monitoring equipment are attached in Appendix 5.1.

Parameters Monitored

5.1.18       In construction phase, the levels of dissolved oxygen (DO), temperature, turbidity and salinity should be measured in situ while suspended solids (SS) is determined by laboratory analysis.

5.2              Monitoring Stations

5.2.1          Water quality monitoring should be conducted at 9 monitoring stations. The locations of water quality monitoring station are shown in Table 5.2.

Table 5.2:    Marine Water Quality Stations for Water Quality Monitoring

Station

Description

Easting

Northing

CE

Upstream control station at ebb tide

810838

807538

CF

Upstream control station at flood tide

815886

808081

SR4 (1)

Ecological Sensitive Receiver (Coral Communities) at Pui O Wan

814938

810975

SR5

Ecological Sensitive Receiver (Coral Communities) at Pui O Wan

814326

810540

SR6

Gazetted Bathing Beach at Lower Cheung Sha

813307

810466

SR9 (1)

Ecological Important Stream at Tong Fuk

811325

809787

SR10

Secondary Contact Recreational Zones at South Lantau

810561

809494

SR12 (1)

Proposed Special Site of Scientific Interest (SSSI) at Shui Hau Wan

810359

808989

SR15

Gazetted Bathing Beach at Pui O and Ecologically Important Stream at Pui O

816037

810722

NOTE:

Fine adjustment of water quality monitoring stations at SR4, SR6, SR9, and SR12 was proposed as per EP Condition 3.1, and baseline monitoring was conducted at corresponding fine adjusted locations.

5.3              Monitoring Date, Time, Frequency and Duration

5.3.1          Baseline Water quality monitoring had been commenced on 12 April 2022 the designated monitoring stations 3 days per week with respect to marine-based construction works commenced on 19 April 2022. HDD casing works commenced on 30 May 2022.

5.3.2          To support water quality monitoring, the silt curtain deployment plan has minor updates to include an additional brand of geosynthetic material as alternative for selection and adopt underwater robot for inspecting condition of silt curtain.

5.3.3          For the upcoming marine works (stage 3 and stage 4), new silt curtain extension to be applied at diffuser and emergency bypass constructions has been proposed and supplemented in the Contract No. SD 15/2022 – Outlying Island Sewerage Stage 2 – South Lantau Sewage Works – Environmental Team Services (2023 – 2024) Monthly EM&A Report (November 2024) 20 EP-538/2017 revised silt curtain deployment plan. Typical details of proposed silt curtain are shown in Figure 5.1.

5.3.4          The levels of dissolved oxygen (“DO”), temperature, turbidity and salinity were measured in situ while suspended solids (“SS”) is determined by laboratory analysis at all the monitoring stations in Table 5.2 3 times a week. Impact monitoring schedule can be referred to Appendix 5.2.

5.3.5          In association with the water quality parameters, other relevant data shall also be recorded, such as monitoring location / position, time, water temperature, DO saturation, weather conditions, and any special phenomena underway near the monitoring station.

5.3.6          Impact Monitoring shall be carried out 3 days per week, at mid-flood and mid-ebb tides (within ± 1.75 hour of the predicted time). The interval between 2 sets of monitoring shall not be less than 36 hours. The monitoring period should avoid concurrent marine project in the vicinity.

5.3.7          The sampling frequency of at least 3 days per week should be undertaken. Upon completion of the construction works, the monitoring exercise at the designated monitoring locations should be continued for 4 weeks in the same manner as the impact monitoring. In case exceedance of Action/Limit Level is recorded, the frequency shall be increased as per the Event and Action Plan.

5.3.8          To ensure the robustness of in-situ measurement, parameters shall be measured in duplicate. In case the difference between duplicates is larger than 25%, a third set of measurement shall be carried out.

Temporary Suspension of Water Quality Monitoring from August 2024 to October 2024

5.3.9          According to the Contractor’s construction programme and confirmed with Engineer Representative, there is no potential marine work until further notice. As such, pursuant to Condition 3.1 of the Environmental Permit No. EP-538/2017, proposal of temporary suspension of impact marine water quality monitoring was submitted to EPD for approval on 12 July 2024. This proposal was reviewed and verified by the Independent Environmental Checker (IEC) on 12 July 2024. The proposal was approved by EPD on 27 August 2024, thus, impact marine water quality monitoring had been temporarily suspended starting from 28 August 2024 and resumed on 7 October 2024.

5.3.10       According to the Contractor’s construction programme, the marine works has been officially commenced on 27 November 2024.

5.4              Monitoring Results

5.4.1          Marine water quality monitoring results measured in this reporting period are reviewed and summarized. Details of marine water quality monitoring results and graphical presentation can be referred in Appendix 5.3.

5.4.2          Water quality monitoring is evaluated against Action and Limit Levels. The derived Action and Limit Level proposed in Baseline Monitoring Report Rev. 9.2 was agreed by EPD on 2 September 2022. Action and Limit Levels of marine water quality monitoring have been set with reference to the derived criteria as shown in Table 5.3 below for reference.

Table 5.3:    Action and Limit Levels of Water Quality

Parameters

Action Level

Limit Level

Construction Phase Marine Water Monitoring - derived criteria

DO in mg/L 1

Surface and Middle: 5.8 mg/L

Bottom: 5.9 mg/L

Surface and Middle: 4 mg/L

Bottom: 2 mg/L

Turbidity in NTU (Depth-averaged 2) 3

14.4 NTU and

20% exceedance of value at any impact station compared with corresponding data from control station 4

23.5 NTU and

30% exceedance of value at any impact station compared with corresponding data from control station 4

SS in mg/L

(Depth-averaged 2) 3

13.1 mg/L and

20% exceedance of value at any impact station compared with corresponding data from control station 4

30.4 mg/L and

30% exceedance of value at any impact station compared with corresponding data from control station 4

Notes (with proposed amendments in AL/LL in underlined text):

1: For DO, non-compliance of the water quality limits occurs when monitoring result is lower than the limits.

2: “Depth-averaged” is calculated by taking the arithmetic means of reading of all 3 depths

3: For SS and turbidity, non-compliance of the water quality limits occurs when monitoring result is higher than the limits.

4: Action Level and Limit Level with 95%-ile / 99%-ile derived from baseline data “and” 20% / 30% exceedance of control station proposed in Baseline Monitoring Report.

5.4.3          During the reporting month, no exceedance was recorded.

6.                 Ecology

6.1              Monitoring Methodology

6.1.1          The weekly site audit to be carried out by the ET should include checking whether good site practices are being properly implemented by the Contractor

6.1.2          Impact monitoring of the transplanted Aquilaris sinensis at holding nursery and 1 retain tree of Aquilaris sinensis in SSWSTW Project Site, establishment and after-establishment caring measures of the compensatory mixed woodland to ensure the affected tree would not be affected by any unacceptable construction works. The trees would be treated with establishment works immediately after transplanting.

6.1.3          Site inspection at the nursery was conducted on 23 April 2025. One reminder was recorded.

6.2              Parameters Monitored

6.2.1          The extent of the work site boundaries should be checked by the ET during the weekly site audit. Any disturbance by the Contractor outside the works area especially any damage to the vegetation and surrounding habitats outside the Project area shall be reported to ER and IEC.

6.2.2          To identify any unacceptable construction works for the trees of Aquilaris sinensis during transplanting, establishment and after-establishment caring measures of the compensatory mixed woodland.

6.3              Monitoring Location

6.3.1          As per latest version of PTP, 4 tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW (Figure 6.1) which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery (Figure 6.2) at Kam Tin and eventually be transplanted to Pui O Pumping Station.

6.4              Monitoring Date, Time, Frequency and Duration

6.4.1          The recommended good site practices to be audited once every week as part of the site audit programme. The weekly site audit to be carried out by the ET includes checking whether good site practices are being properly implemented by the Contractor. Results are recorded in Weekly Environmental Site Audit Checklist.

6.4.2          Monitoring programme for post-transplantation was conducted on 24 March 2025 once per month.

6.5              Monitoring Results

6.5.1          The weekly site audit was carried out by ET include checking whether good site practices are being properly implemented by the Contractor.

6.5.2          The extent of the work site boundaries was checked by the ET during the weekly site audit.

6.5.3          Results and findings of site audit in this reporting month are listed in Table 3.3.

7.                 Waste Management

7.1.1          The quantities of waste for disposal in the Reporting Period are summarized in Table 7.1. The Monthly Summary Waste Flow Table is shown in Appendix 7.1.

Table 7.1:    Summary of Quantities of Waste Material

Waste Type

Quantity this month

Quantity (the end of last month)

Cumulative Quantity-to-Date

Hard Rock and Large Broken Concrete (Inert), in ‘000m3

0

0

0

Reused in this Contract (Inert), in ‘000m3

0

0

0

Reused in other Projects (Inert), in ‘000m3

0

0

0

Disposal as Public Fill (Inert), in ‘000m3

0.39

0.68

29.48789

Metals, in ‘000kg

0.0069

0

15.78377

Paper / Cardboard Packing, in ‘000kg

0.0528

0

1.03058

Plastics, in ‘000kg

0.0002

0

0.10016

Chemical Wastes, in ‘000kg

0

0

0

General Refuses, in ‘000kg

25.38

10.86

799.25

Marine Sediment (Type 1 – Open Sea Disposal), m3

0

0

1360.2

NOTE:

The inert waste disposal record up to 7 April 2025 was based on the onsite record from the contractor instead of the official record from the Mui Wo Public Fill Reception Facility due to the maintenance of the weighting bridge. The subsequent inert waste disposal record will adopt the recorded weight at the Mui Wo Public Fill Reception Facility.

8.                 Complaints, Notification of Summons and Prosecution

8.1.1          No environmental complaint was recorded in the reporting month.

8.1.2          No notification of summons and successful prosecution regarding construction works were recorded in the reporting month.

8.1.3          Cumulative statistic on complaints, summary of complaints and successful prosecutions are summarized in Table 8.1, Table 8.2 and Table 8.3 respectively.

Table 8.1:    Cumulative Statistics on Complaints

Reporting Period

No. of Complaints

Project commencement to the end of last reporting month

3

This Reporting Month (April 2025)

0

Total:

3

 

Table 8.2:    Summary of Complaints

Date of Notification from EPD

Date of Complaint

Description of Complaint

Validity of Complaint

Close-Out Date / Status

26 May 2022

22 May 2022

A complaint is regarding to noise nuisance from marine site of San Shek Wan, Lantau Island.

Based on the investigation, the works activities of marine works did not result in any noise nuisance to Noise Sensitive Receivers (NSRs), noise nuisance from the Project is unlikely to be valid.

The interim report was submitted to EPD in June 2022. EPD replied no further comments on the final investigation report on 13 July 2022.

23 Dec 2022

21 Dec 2022

A complaint is regarding to the water quality for Pui O Beach, Lantau Island.

Based on the investigation, the works activities at POPS did not result in any water quality impacts to the Pui O Beach.

The interim report was submitted to EPD on 4 Jan 2023.

16 Aug 2024

15 Aug 2024

A complaint is regarding to the damaged silt curtain and potential water quality impact.

Based on the investigation, no marine works since Dec 2023 till present, the land based works activities at POPS did not result in any water quality impacts to the Pui O Wan

The interim report was submitted to EPD on 31 Aug 2024.

 

Table 8.3:    Cumulative Statistics on Successful Prosecutions

Environmental Parameters

Cumulative No. Brought Forward

No. of Successful Prosecutions this month (Offence Date)

Cumulative No. Project-to-Date

Air

-

0

0

Noise

-

0

0

Water

-

0

0

Waste

-

0

0

Other

-

0

0

Total

-

0

0

 

9.                 Future Key Issues

9.1.1          In coming reporting 3 months, the scheduled construction activities are listed as follows:

Ø Excavation, sewer laying, construction of manhole at Pui O Lo Uk Tsuen, South Lantau Road, Chi Ma Wan Road

Ø Excavation and site formation at SSWSTW

Ø Trenchless drilling works (Chi Ma Wan Road)

Ø Excavation and ELS work at POSPS

Ø Superstructure RC works at SSWSTW

Ø Retaining wall construction at SSWSTW

Ø Dredging and diffuser construction at SSWSTW

Ø E&M Installation at POSPS

9.1.2          The scheduled construction activities and the recommended mitigation measures for the coming 3 months are listed in Table 9.1. The major construction activities for the next 3 months are summarized in 3 Months Rolling Programme – April 2025 to June 2025 in Appendix 9.1

Table 9.1:    Construction Activities and Recommended Mitigation Measures in Coming Reporting 3 Months

Key Construction Works

Recommended Mitigation Measures

·         Excavation, sewer laying, construction of manhole at Pui O Lo Uk Tsuen, South Lantau Road, Chi Ma Wan Road

·         Excavation and site formation at SSWSTW

·         Trenchless drilling works (Chi Ma Wan Road)

·         Excavation and ELS work at POSPS

·         Superstructure RC works at SSWSTW

·         Retaining wall construction at SSWSTW

·         Dredging and diffuser construction at SSWSTW

·         E&M Installation at POSPS

·         Implementation of noise pollution control in accordance with Construction Noise Mitigation Plan;

·         Dust control during dust generating works;

·         Silt curtain should be maintained in good condition prior to and during dredging and related marine works;

·         Adopt surface drainage and sediment control facilities for sewage installation in village and public roads;

·         Adopt temporary drainage and sediment control facilities on Site;

·         Vehicle wheel-washing and body washing facilities should be provided at the site entrance;

·         Regular water spraying on excavation works for dust control; and

·         Proper waste handling, recycling and storage.

 

 

10.              Conclusion

10.1           Noise Monitoring

10.1.1       Noise Monitoring has been conducted at 8 of the designated monitoring locations where construction works has been conducted nearby during the reporting month.

10.1.2       No action or limit level exceedance was recorded in construction noise level in this reporting period.

10.2           Water Quality Monitoring

10.2.1       Marine Water Monitoring has been conducted at 9 designated monitoring locations during the reporting month.

10.2.2       No action or limit level exceedances were recorded within the reporting month.

10.3           Ecological Impact Monitoring

10.3.1       Transplanting of the trees of Aquilaris sinensis was completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.

10.3.2       As per latest version of PTP, 4 tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery at Kam Tin and eventually be transplanted to Pui O Pumping Station.

10.3.3       The weekly site audit was carried out by ET include checking whether good site practices are being properly implemented by the Contractor.

10.3.4       The extent of the work site boundaries was checked by the ET during the weekly site audit.

10.3.5       Within this reporting period, holding nursery visit for transplanted trees on 23 April 2025.

10.3.6       No non-compliance was found during the site inspection while reminders on environmental measures were recommended. Results and findings of these inspections in this reporting period are listed below in Table 10.1

Table 10.1: Summary of Ecological Impact Monitoring

Inspection Date

Reminder and Recommendations

Close-out Date / Status

23 April 2025

The contractor is reminded to properly install the tree label.

-N/A-

10.4           Review of the Reasons for and the Implications of Non-compliance

10.4.1       No environmental non-compliance was recorded in the reporting month.

10.5           Summary of Action Taken in the Event of and Follow-Up on Non-Compliance

10.5.1       There was no particular action taken since no non-compliance was recorded in the reporting period.

10.5.2       The performance of the environmental management system of the reporting period was generally satisfied. Mitigation measures according to the environmental mitigation implementation schedule and the EIA were generally implemented by the Contractor. Hence, the EM&A programme was considered effective and shall be maintained.