CONTRACT NO: SD 15/2022   Outlying Island Sewerage Stage 2 – South Lantau Sewage    Works – Environmental Team Services (2023 – 2024)   Under Environmental Permit no. EP-538/2017   Monthly Environmental Monitoring & Audit Report   october 2024 revision 4

Table of contents

1............. Introduction.. 7

1.1.......... Scope of the Report 7

1.2.......... Structure of the Report 7

2.............. Basic project Information and Environmental Status. 9

2.1.......... Basic Project Information.. 9

2.2.......... Construction Programme. 9

2.3.......... Works undertaken during the month.. 10

2.4.......... Drawing showing the project area, environmental sensitive receivers and monitoring locations. 10

3............. Implementation Status. 10

3.1.......... Advice on the implementation status of environmental protection and pollution control/mitigation measures. 10

3.2.......... Environmental Mitigation Measures. 11

3.3.......... Environmental monitoring requirements and contractual requirements. 11

3.4.......... Site Inspection and Audit Reports. 12

4............. Monitoring Results. 14

4.1.......... Noise Monitoring. 14

4.2.......... Water Quality Monitoring. 17

4.3.......... Ecology. 22

4.4.......... Waste Management 23

5............. Complaints, Notification of Summons and Prosecution.. 25

6............. Future Key Issues. 27

7............. Conclusion.. 28

7.1.......... Noise Monitoring. 28

7.2.......... Water Quality Monitoring. 28

7.3.......... Ecological Impact Monitoring. 29

7.4.......... Review of the Reasons for and the Implications of Non-compliance. 30

7.5.......... Summary of action taken in the event of and follow-up on non-compliance. 30

 

 

           

lIST OF TABLES

 

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 4.3       Water Quality Monitoring Equipment

Table 4.4     Marine Water Quality Stations for Water Quality Monitoring

Table 4.5     Action and Limit Levels of Water Quality

Table 4.6     Summary of Marine Water Quality Exceedances

Table 4.7       Summary of Quantities of Waste Material

Table 5.1       Cumulative Statistics on Complaints

Table 5.2       Summary of Complaints

Table 5.3       Cumulative Statistics on Successful Prosecutions

Table 6.1       Construction Activities and Recommended Mitigation Measures in Coming Reporting 3 Months

 

 

lIST OF 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 2.5    Mark up Figure 5.4i extracted from approved EIA Report (AEIAR-210/2017)

Figure 2.6    Location Plan for Temporary Holding Nursery

Figure 2.7  Typical Details of Proposed Silt Curtain

 

 

lIST OF APPENDIces

 

Appendix 4.1    Copies of Calibration Certificates

Appendix 4.2    Impact Monitoring Schedule for Reporting Month and Next Month

Appendix 4.3    Noise Monitoring Results and Graphical Presentations

Appendix 4.4    Marine Water Quality Monitoring Results and Graphical Presentations

Appendix 4.5    Monthly Summary Waste Flow Table

Appendix 6.1    3 Months Rolling Programme

 

EXECUTIVE SUMMARY

       i.        This is the Monthly Environmental Monitoring and Audit (EM&A) Report – October 2024 for the Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works under Environmental Permit No. EP-538/2017 (Hereafter as “the Project”).  The construction works of the Project was commenced on 3 November 2021 and the tentative completion date is Q1 2026.  This Monthly EM&A Report presents the environmental monitoring findings and information recorded during the period of 1 to 31 October 2024. The cut-off date of reporting is at the end of each reporting month.

      ii.        In the reporting period, the principal work activities undertaken are 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 San Shek Wan Sewage Treatment Works (SSWSTW) and Pui O Sewage Pumping Station (POSPS)

·          Removal works of Excavation and Lateral Support (ELS)

·          ELS works

·          Superstructure Reinforced Concrete (RC) Works

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

 

 

Exceedances of Action/Limit Levels

Noise Monitoring

     iii.        Noise monitoring was conducted at eight (8) noise monitoring stations (N12a, N12b, N13, N14, N15b, N16a, N16b and N17) once per week in the reporting period.

     iv.        No school examination was taken place at N17 – Bui O Public School in the reporting period.

      v.        No Action/Limit Level exceedances were recorded in this reporting period.

 

Water Quality Monitoring

     vi.        Water quality monitoring (WQM) had been commenced on 12 April 2022 the designated monitoring stations three days per week with respect to marine-based construction works commenced on 19 April 2022. HDD casing works commenced on 30 May 2022.

    vii.        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 on 12 July 2024 for approval. 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 until further notice. Once Contractor and Engineer Representative confirm the actual date to resume marine work, ET will notify EPD one month in advance, and ET will resume impact marine water quality monitoring two weeks prior to the start of marine works.

 

   viii.        According to the Contractor’s construction programme and confirmed with Engineer Representative (Binnies), the marine works will be tentatively commenced on 21 October 2024, ET notified EPD immediately on 17 September 2024 to resume the marine water quality monitoring two weeks prior to commencement of marine works, WQM was resumed from 7 Oct 2024.

 

     ix.        Further confirmed with the Contactor and ER, marine works has yet to resume and no marine work were ongoing in October 2024.

 

      x.        In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR9, SR10 and SR12 from 07:56 to 08:12 during ebb tide on 12 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR5 and SR6 from 9:07 to 9:19 during flood tide as well as at SR10 and SR12 from 14:04 to 14:11 during ebb tide on 21 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR15 from 13:37 to 13:38 during flood tide on 23 Oct 2024. Limit level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR4 and SR15 from 09:20 to 09:30 during ebb tide on 28 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR5, SR6, SR9,SR10, and SR12 from 09:38 to 10:24 during ebb tide as well as at SR4, SR5, SR6, SR9,SR10, SR12and SR15 from 16:01 to 17:07 during flood tide on 28 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR10 and SR12 during both ebb and flood tide from 11:25 to 11:32 and 16:32 to 16:38 respectively on 30 Oct 2024.

 

     xi.        As the suspended solids (SS) result is determined by laboratory analysis that require 7 working days, it is not possible to increase the monitoring frequency to daily until no exceedance of Action Level after 30 Oct 2024. If such exceedances continuous during marine works commencement, ET will check with contractor the implementation of the mitigation measures and daily WQM monitoring will be considered.

 

    xii.        As no marine work were ongoing since Jan 2024, no sign of pollution was observed during site inspection or marine water samples collection, it is considered that the exceedance was not related to Project works.

 

   xiii.        For the limit level exceedances of suspended solid recorded on 28 Oct 2024, confirmed with our field technician, the seawater was observed turbid during sampling. As no marine work was conducted in Oct 2024 and no other evidence indicate that the limit level exceedance was affected by the site activities, it can be concluded that the limit level exceedances were possibly induced by other factors such as natural variation or changes of water quality in the vicinity of water quality monitoring station.

 

 

Ecological Impact Monitoring

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

    xv.        As per latest version of PTP, four 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.

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

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

 

Complaint log

 xviii.        No environmental complaint regarding the construction works was recorded in the reporting period.

 

Notifications of Any Summons and Successful Prosecutions

   xix.        No environmental notification of any summons and successful prosecution regarding the construction works was recorded in the reporting period.

 

Reporting Changes

    xx.        There are no particular reporting changes.

Future Key Issues

   xxi.        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

·          Dredging at marine *

·          Site formation works at SSWSTW

·          Trenchless drilling works (Chi Ma Wan Road)

·          Excavation works (at site area)

·          ELS works at SSWSTW

·          Superstructure RC Works at SSWSTW

·          Removal works of ELS at POSPS

·          E&M Installation at POSPS

* Note: Further confirmed with the Contactor and ER, marine works has yet to resume and no marine work were ongoing in October 2024. The impact marine water quality monitoring was resumed from 7 October 2024.

 

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

 

Introduction

1.1          Scope of the Report

1.1.1.     Lam Environmental Services Limited (LES) has been appointed to work as the Environmental Team (ET) under Environmental Permit (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 Environmental Impact Assessment (EIA) Report for the Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works (Register No.: AEIAR-210/2017).

1.1.2.     In accordance with Clause 3.4 stated in EP-538/2017, 4 hard copies and 1 electronic copy of Monthly EM&A Report shall be submitted to the Director within 2 weeks after the end of each reporting month.

1.1.3.     According to Section 12.2 of the Project EM&A Manual, the Monthly EM&A Report should be submitted within 10 working days of the end of each reporting month, with the first report due in the month after construction commences.

1.2          Structure of the Report

Section 1        Introduction – details the scope and structure of the report.

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.

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.

Section 4        Monitoring Results – 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.

Section 5        Report on Complaints, Notification of Summons and Successful Prosecutions – summarizes:

                       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;

                       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;

 

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

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

Section 6        Future Key Issues – An account of the future key issues as reviewed from the works programme and work method statements.

Section 7        Conclusion

 

2                    Basic project Information and Environmental Status

2.1          Basic Project Information

2.1.1. Drainage Services Department is the overall project controllers for the Project. For the       construction phase of the Project, Contractor(s), Environmental Team and Independent      Environmental Checker are appointed to manage and control environmental issues. Key      personnel and contact particulars are summarized in Table 2.1:

 

             Table 2.1     Contact Details of Key Personnel

 

Party	Role	Post	Name	Contact No.	Contact Fax
Drainage Services Department (DSD)	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 Officer	Ms. Hassan Ka Sin / Mr. Rico Chan	6993 0990 / 6224 9332
SMEC Hong Kong	Independent Environmental Checker (IEC)	Independent Environmental Checker (IEC)	Ms. Kitty Lee	3995 8140	3422 3631
Lam Environmental Services Limited	Environmental Team (ET)	Environmental Team Leader (ETL)	Mr. Derek Lo	2882 3939	2882 3331

 

2.2          Construction Programme

2.      

2.1.      

2.2.      

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 entire Project are divided into three contracts. Contract No. DC/2020/20 (the Contract) would have the following implementations as demonstrated in Figure 2.1.

2.2.3.     The major components of the Contract under Environmental Permit (EP) (EP No. EP-538/2017) comprises: (i) construction of secondary sewage treatment works (STW) at San Shek Wan in South Lantau; (ii) construction of sewage pumping station (SPS) at Pui O, San Shek Wan, Cheung Sha and Cheung Fu Street; (iii) construction of about 1.4 kilometres (km) of submarine outfall with a diameter of 350 millimetres (mm) for the disposal of treated effluent from the STW at San Shek Wan; (iv) construction of about 10.1 km of gravity sewers with diameters ranging from 150 mm to 375 mm along South Lantau Road and Chi Ma Wan road and at Pui O; and (v) construction of about 3.1 km twin rising mains with a diameter of 200 mm to 250 mm along South Lantau Road and Chi Ma Wan Road.

2.2.4.     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.

 

2.3          Works undertaken during the month

2.3.      

2.3.1.     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 Sewage Treatment Works (SSWSTW) and Pui O Sewage Pumping Station (POSPS)

·          Removal works of Excavation and Lateral Support (ELS)

·          ELS works

·          Superstructure Reinforced Concrete (RC) Works

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

 

The locations of works are shown in Figure 2.2.

2.4          Drawing showing the project area, environmental sensitive receivers and monitoring locations

2.4.      

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

 

3              Implementation Status

3.1          Advice on the implementation status of environmental protection and pollution control/mitigation measures

3.      

3.1.      

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.      

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 Environmental Permit (EP-538/2017) are shown in Table 3.1.

 

Table 3.1     Summary of submission status under EP-538/2017

 

3.3          Environmental monitoring requirements and contractual requirements

3.3.      

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	30-12-2021 to 31-12-2026	Valid
	POPS: WT00039820-2021	31 Dec 2021	31-12-2021 to 31-12-2026	Valid
	SSWSTW: Gravity Sewer & Raising Main: WT00042613-2022	09 Jan 2023	09-01-2023 to 31-01-2028	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-RS0658-24	17 July 2024	09-08-2024 to 08-02-2025	Valid
Construction Noise Permit under Noise Control Ordinance for POSPS	GW-RS0856-24	17 Sep 2024	27-09-2024 to 26-03-2025	Valid
Marine Dumping Permit (Dredged Sediment Requiring Type 1 – Open Sea Disposal	-	-	-	Renewed Marine Dumping Permit under application

Note: Only include those valid or under application; fill in “N/A” for non-applicable item(s).

 

3.4          Site Inspection and Audit Reports

6.      

7.      

7.0.      

3.4.      

3.4.1.     Within this reporting month, weekly environmental site inspections were conducted on 02, 08, 17, 21 and 29 October 2024. IEC attended the SSEMC meeting held on 21 October 2024. Holding nursery visit for transplanted trees on 23 October 2024.

3.4.2.     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 month are listed below in Table 3.3.

 

 

Table 3.3          Summary of Environmental Inspections

 

Inspection Date	Reminder and Recommendations	Close-out Date / Status
2 October 2024	Pui O Sewage Pumping Station (POSPS) – Obs1: Water barriers and cover at site boundary were found damaged by strong wind, contractor is requested to fix/replace the damaged barriers and cover. San Shek Wan Sewage Treatment Works (SSWSTW) – R1. Tarpaulin sheets on slope found damaged by strong wind, contractor is reminded to arrange replacement.	Rectified by the Contractor on 8 October 2024
8 October 2024	Pui O Sewage Pumping Station (POSPS) – Obs.1: Sediment accumulated in the wheel washing facilities should be removed regularly Obs.2: Construction waste outside the site boundary should be removed regularly South Lantau Road (car park area) Rising Mains – Obs.3: Direct discharge observed, contractor is requested to stop immediately and re-connected to silt removal facilities prior to discharge San Shek Wan Sewage Treatment Works (SSWSTW) – R1. Contractor is reminded to provide regular watering on main haul road during dry season.	Rectified by the Contractor on 8 November 2024
17 October 2024	Pui O Sewage Pumping Station (POSPS) – Obs.1: Copies of Environmental Permit (EP) should be displayed at site entrances San Shek Wan Sewage treatment Works(SSWSTW) –  Obs.2: drip tray should be provided to chemical container	Rectified by the Contractor on 21 October 2024
21 October 2024	Pui O Sewage Pumping Station (POSPS) – Obs.1: Drip tray should be provided to chemical container	Chemical container was removed during site inspection on 29 Oct 2024
29 October 2024	Pui O Sewage Pumping Station (POSPS) – Obs.1: Drip tray should be provide to chemical container	Rectified by the Contractor on 5 November 2024

.1. 

 

4              Monitoring Results

4.1          Noise Monitoring

Monitoring methodology

4.1.1      Monitoring Procedure

(a)           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.

(b)           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.

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

(d)           The battery condition was checked to ensure the correct functioning of the meter.

(e)           Parameters such as frequency weighting, the time weighting and the measurement time were set as follows:

(f)            Frequency weighting: A, Time weighting: Fast, Measurement time set: continuous 5 mins

(g)           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 re-calibration or repair of the equipment.

(h)           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.

 

name of laboratory and equipment used and calibration details

4.1.2      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	Series Number
Integrated Sound Level Meter	Larson Davis LxT1	0004797
Acoustic Calibrator	Larson Davis CAL200	13128

 

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

 

4.1.4      Calibration Details

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

(b)           The sound level meter and calibrator were calibrated at yearly intervals.

 

Parameters monitored

4.1.5      The construction noise level shall be measured in terms of the A-weighted equivalent continuous sound pressure level (L_eq). L_eq(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.

4.1.6      For impact monitoring for construction of village sewers / rising main, noise monitoring should be undertaken on weekly basis. One set of L_eq(30min) noise level as six consecutive L_eq(5min) between 07:00-19:00 hours on normal weekdays.

 

Monitoring Stations

4.1.7      The noise monitoring stations for the Project are listed and shown in Table 4.2, impact noise monitoring was conducted at Eight (8) noise monitoring stations N12a, N12b, N13, N14, N15b, N16a, N16b and N17 once per week in the reporting month.

 

Table 4.2     Noise Monitoring Station

Remarks (1): Fine adjustment of noise monitoring stations at all locations was proposed as per EP Condition 3.1.

 

Monitoring date, time, Frequency and Duration

4.1.8      For daytime construction work on normal weekdays, monitoring of L_eq(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.

 

Noise Monitoring Results

5.0.       

4.1.9      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.

4.1.10    No school examination was taken place at N17 – Bui O Public School in the reporting period.

 

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

 

4.2          Water Quality Monitoring

Monitoring Methodology

4.2.1      Monitoring Procedure

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

(b)           Check of sensors and electrodes with certified standard solutions before each use.

(c)           Wet bulb calibration for a DO meter should be carried out before measurement.

(d)           Water depth should be recorded by detector before sampling.

(e)           Sample would be taken using bucket sampler at surface level.

(f)            Transfer the sampled water carefully into cleaned water bottles (2x 1000ml) provided by the laboratory at the spot after the collection of the water sample for the subsequent laboratory Suspended Solid testing.

(g)           Transfer the sampled water from the bucket sampler to the rinsed water container for in-situ measurement (In case of the in-situ measurement cannot be carried at spot due to safety and adverse weather condition, sampled water from the bucket sampler will be transfer to cleaned water bottles provided by laboratory. Then, In-situ measurement will be conducted at a safe location which sampled water inside cleaned water bottle will be transfer to the rinsed water container for in-situ measurement) In-situ measurement shall be measured in duplicate.

(h)           Parameters including Water Temperature (°C), pH (units), Salinity (ppt), DO (mg/L), DO saturation (%) will be measured by the Multifunctional Meter and Turbidity (NTU) will be measured by turbid meter. (Water Temperature and Salinity will be measured as reference parameters)

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

(j)             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 SS.

 

Name of laboratory and equipment used and calibration details

Laboratory Measurement / Analysis

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

 

equipment used

Dissolved Oxygen, pH And Temperature Measuring Equipment

4.2.3      Multifunctional Meter and Turbid 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)

 

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^o, Detection Limit: 1mm/s)

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

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

 

Sampler Container and Storage

4.2.4      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

4.2.5      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

4.2.6      Maintenance and Calibration

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

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

 

4.2.7      Brand and model of the equipment are given in Table 4.3.

 Table 4.3   Water Quality Monitoring Equipment

 

Equipment	Brand and model	Series Number
Multifunctional Meter	YSI Professional Plus	17G100383
Turbid meter	WGZ-3B	1807063

 

 

Calibration certificates of the water quality monitoring equipment are attached in Appendix 4.1.

 

Parameters monitored

4.2.8      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.

 

MONITORING STATIONS

4.2.9      Water quality monitoring involves 9 monitoring stations. The locations of water quality monitoring station are shown in Table 4.4.

Table 4.4    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	810553	810475
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

Remarks (1): Fine adjustment of water quality monitoring stations at SR4, SR9 and SR12 was proposed as per EP Condition 3.1, and baseline monitoring was conducted at corresponding fine adjusted locations.

 

Monitoring date, time, Frequency and Duration

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

4.2.11    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.

4.2.12    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 revised silt curtain deployment plan. Typical details of proposed silt curtain are shown in Figure 2.7.

 

4.2.13    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 4.4 three times a week. Impact monitoring schedule can be referred to Appendix 4.2.

4.2.14    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.

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

4.2.16    The sampling frequency of at least three days per week should be undertaken. Upon completion of the construction works, the monitoring exercise at the designated monitoring locations should be continued for four 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.

4.2.17    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.

Monitoring Results

5 

 

4.2.18    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 4.4

4.2.19    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 4.5 below for reference.

Table 4.5     Action and Limit Levels of Water Quality

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

A. “Depth-averaged” is calculated by taking the arithmetic means of reading of all three depths.

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

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

D. 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.

 

4.2.20    Number of exceedances recorded during the reporting month are summarized in Table 4.6.

Table 4.6     Summary of Marine Water Quality Exceedances

	Parameter	DO (S&M)		DO (Bottom)		Turbidity		SS		Exceedance count
Station	Level exceeded	Mid Ebb	Mid Flood	Mid Ebb	Mid Flood	Mid Ebb	Mid Flood	Mid Ebb	Mid Flood	Mid Ebb	Mid Flood
SR4	Action	/	/	/	/	/	/	/	/	0	0
	Limit	/	/	/	/	/	/	1	/	1	0
SR5	Action	/	/	/	/	/	/	1	2	1	2
	Limit	/	/	/	/	/	/	/	/	0	0
SR6	Action	/	/	/	/	/	/	1	2	1	2
	Limit	/	/	/	/	/	/	/	/	0	0
SR9	Action	/	/	/	/	/	/	2	1	2	1
	Limit	/	/	/	/	/	/	/	/	0	0
SR10	Action	/	/	/	/	/	/	4	2	4	2
	Limit	/	/	/	/	/	/	/	/	0	0
SR12	Action	/	/	/	/	/	/	4	2	4	2
	Limit	/	/	/	/	/	/	/	/	0	0
SR15	Action	/	/	/	/	/	/	/	2	0	2
	Limit	/	/	/	/	/	/	1	/	1	0
Total	Action	0	0	0	0	0	0	12	11	23
	Limit	0	0	0	0	0	0	2	0	2

 

4.2.21    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 until further notice. Once Contractor and Engineer Representative confirm the actual date to resume marine work, ET will notify EPD one month in advance, and ET will resume impact marine water quality monitoring two weeks prior to the start of marine works.

4.2.22    According to the Contractor’s construction programme and confirmed with Engineer Representative (Binnies), the marine works will be commenced on 21 October 2024, ET notified EPD immediately on 17 September 2024 to resume the marine water quality monitoring two weeks prior to commencement of marine works, WQM was resumed from 7 Oct 2024.

4.2.23    Further confirmed with the Contactor and ER, marine works has yet to resume and no marine work were ongoing in October 2024.

 

 

 

4.2.24    In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR9, SR10 and SR12 from 07:56 to 08:12 during ebb tide on 12 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR5 and SR6 from 9:07 to 9:19 during flood tide as well as at SR10 and SR12 from 14:04 to 14:11 during ebb tide on 21 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR15 from 13:37 to 13:38 during flood tide on 23 Oct 2024. Limit level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR4 and SR15 from 09:20 to 09:30 during ebb tide on 28 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR5, SR6, SR9,SR10, and SR12 from 09:38 to 10:24 during ebb tide as well as at SR4, SR5, SR6, SR9,SR10, SR12and SR15 from 16:01 to 17:07 during flood tide on 28 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR10 and SR12 during both ebb and flood tide from 11:25 to 11:32 and 16:32 to 16:38 respectively on 30 Oct 2024.

4.2.25    As the suspended solids (SS) result is determined by laboratory analysis that require 7 working days, it is not possible to increase the monitoring frequency to daily until no exceedance of Action Level after 30 Oct 2024. If such exceedances continuous during marine works commencement, ET will check with contractor the implementation of the mitigation measures and daily WQM monitoring will be considered.

4.2.26    As no marine work were ongoing since Jan 2024, no sign of pollution was observed during site inspection or marine water samples collection, it is considered that the exceedance was not related to Project works.

4.2.27    For the limit level exceedances of suspended solid recorded on 28 Oct 2024, confirmed with our field technician, the seawater was observed turbid during sampling. As no marine work was conducted in Oct 2024 and no other evidence indicate that the limit level exceedance was affected by the site activities, it can be concluded that the limit level exceedances were possibly induced by other factors such as natural variation or changes of water quality in the vicinity of water quality monitoring station.

 

4.3          Ecology

MONITORING METHODOLOGY

4       

4.1       

4.2       

4.3       

4.3.1      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.

 

 

 

4.3.2      Impact monitoring of the transplanted Aquilaris sinensis at holding nursery and one 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.

 

PARAMETERS MONITORED

4.3.3      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.

4.3.4      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.

 

MONITORING LOCATION

4.3.5       As per latest version of PTP, four tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW (Figure 2.5) which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery (Figure 2.6) at Kam Tin and eventually be transplanted to Pui O Pumping Station.

 

MONITORING DATE, TIME, FREQUENCY AND DURATION

4.3.6      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.

4.3.7       Monitoring programme for post-transplantation was conducted on 23 October 2024 once per month.

 

MONITORING RESULTS

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

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

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

 

4.4       Waste Management

4.4.1       The quantities of waste for disposal in the Reporting Period are summarized in Table 4.7. The Monthly Summary Waste Flow Table is shown in Appendix 4.5.

Table 4.7     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)	0.38	1.53802	25.09089
Metals (in ‘000kg)	0	0.00300	15.69570
Paper / Cardboard Packing (in ‘000kg)	0	0.01100	0.83538
Plastics (in ‘000kg)	0	0.00190	0.07496
Chemical Wastes (in ‘000kg)	0	0	0
General Refuses (in ‘000kg)	12.49	15.89000	683.21
Marine Sediment (Type 1 – Open Sea Disposal) , m3	0	0	60.2

 

 

5              Complaints, Notification of Summons and Prosecution

8.        

8.0.        

5.1.1       No environmental complaint was recorded in the reporting month.

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

5.1.3       Cumulative statistic on complaints, summary of complaints and successful prosecutions are summarized in Table 5.1, Table 5.2 and Table 5.3 respectively.

 

 

 

 

 

Table 5.1     Cumulative Statistics on Complaints

Reporting Period	No. of Complaints
October 2024	0
Project commencement to the end of last reporting month	3
Total	3

 

 

Table 5.2     Summary of Complaints

 

 

 

 

 

Table 5.3     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

 

 

6              Future Key Issues

9.        

9.0.        

6.1.1       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

·          Dredging at marine *

·          Site formation works at SSWSTW

·          Trenchless drilling works (Chi Ma Wan Road)

·          Excavation works (at site area)

·          ELS works at SSWSTW

·          Superstructure RC Works at SSWSTW

·          Removal works of ELS at POSPS

·          E&M Installation at POSPS

* Note: Further confirmed with the Contactor and ER, marine works has yet to resume and no marine work were ongoing in October 2024. The impact marine water quality monitoring was resumed from 7 October 2024.

 

6.1.2       The scheduled construction activities and the recommended mitigation measures for the coming 3 months are listed in Table 6.1. The major construction activities for the next 3 months are summarized in Three Months Rolling Programme – November 2024 to January 2025 in Appendix 6.1.

Table 6.1     Construction Activities and Recommended Mitigation Measures in Coming Reporting 3 Months

 

7              Conclusion

7.1          Noise Monitoring

7.1.1       No school examination was taken place at N17 – Bui O Public School in the reporting period.

 

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

 

7.2          Water Quality Monitoring

7.2.1      Marine-based construction works commenced on 19 April 2022, HDD casing works commenced on 30 May 2022.

7.2.2       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 until further notice. Once Contractor and Engineer Representative confirm the actual date to resume marine work, ET will notify EPD one month in advance, and ET will resume impact marine water quality monitoring two weeks prior to the start of marine works.

7.2.3       According to the Contractor’s construction programme and confirmed with Engineer Representative (Binnies), the marine works will be commenced on 21 October 2024, ET notified EPD immediately on 17 September 2024 to resume the marine water quality monitoring two weeks prior to commencement of marine works, WQM was resumed from 7 Oct 2024.

7.2.4       Further confirmed with the Contactor and ER, marine works has yet to resume and no marine work were ongoing in October 2024.

 

7.2.5       In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR9, SR10 and SR12 from 07:56 to 08:12 during ebb tide on 12 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR5 and SR6 from 9:07 to 9:19 during flood tide as well as at SR10 and SR12 from 14:04 to 14:11 during ebb tide on 21 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR15 from 13:37 to 13:38 during flood tide on 23 Oct 2024. Limit level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR4 and SR15 from 09:20 to 09:30 during ebb tide on 28 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR5, SR6, SR9,SR10, and SR12 from 09:38 to 10:24 during ebb tide as well as at SR4, SR5, SR6, SR9,SR10, SR12and SR15 from 16:01 to 17:07 during flood tide on 28 Oct 2024. Action level exceedances of Depth-averaged on suspended solids (SS) was recorded at SR10 and SR12 during both ebb and flood tide from 11:25 to 11:32 and 16:32 to 16:38 respectively on 30 Oct 2024.

7.2.6       As the suspended solids (SS) result is determined by laboratory analysis that require 7 working days, it is not possible to increase the monitoring frequency to daily until no exceedance of Action Level after 30 Oct 2024. If such exceedances continuous during marine works commencement, ET will check with contractor the implementation of the mitigation measures and daily WQM monitoring will be considered.

7.2.7       As no marine work were ongoing since Jan 2024, no sign of pollution was observed during site inspection or marine water samples collection, it is considered that the exceedance was not related to Project works.

7.2.8       For the limit level exceedances of suspended solid recorded on 28 Oct 2024, confirmed with our field technician, the seawater was observed turbid during sampling. As no marine work was conducted in Oct 2024 and no other evidence indicate that the limit level exceedance was affected by the site activities, it can be concluded that the limit level exceedances were possibly induced by other factors such as natural variation or changes of water quality in the vicinity of water quality monitoring station.

 

7.3          Ecological Impact Monitoring

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

7.3.2       As per latest version of PTP, four 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.

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

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

7.3.5       Within this reporting period, holding nursery visit for transplanted trees on 23 October 2024.

7.3.6       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 7.1.

 

 

Table 7.1          Summary of Ecological Impact Monitoring

 

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

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

 

7.5          Summary of action taken in the event of and follow-up on non-compliance

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