REVISION HISTORY

 

REV.

DESCRIPTION OF MODIFICATION

DATE

 

A

 

First Issue for Comments

 

08/12/2022

 

B

 

Revised according to IEC's Comments

 

14/12/2022

 

C

 

Revised according to SO R's Comments

 

19/12/2022

 

 

 

 

 

 


CONTENTS

Executive Summary............................................................................................................................................................... 1

1.           Basic Contract Information................................................................................................................................... 7

2.           Noise........................................................................................................................................................................ 12

3.          Water Quality........................................................................................................................................................ 16

4.          Waste........................................................................................................................................................................ 24

5.          Landfill Gas Monitoring...................................................................................................................................... 25

6.          Ecology..................................................................................................................................................................... 28

7.          Summary of Exceedance, Complaints, Notification of Summons and Prosecutions................ 29

8.           EM&A Site Inspection.......................................................................................................................................... 31

9.          Future Key Issues................................................................................................................................................. 32

10.       Conclusions and  Recommendations................................................................................................................ 35


文字方塊: .l
 

 


Appendix A        Master Programme

Appendix B        Overview of Desalination Plant in Tseung Kwan 0

Appendix C        Summary of Implementation Status of Environmental Mitigation

Appendix D        Impact Monitoring Schedule

Appendix E         Event/Action Plan

Appendix F         Water Quality and Landfill Gas Equipment Calibration Certificate

Appendix G        Water Quality and Landfill Gas Monitoring Data

Appendix H        Waste Flow Table

Appendix I          Site Inspection Proforma

Appendix J          Complaint Log

Appendix K        Exceedance Report(s)

 

 

 

 

 


 

EXECUTIVE SUMMARY

 

 

INTRODUCTION

 

Al. The Project, Design, Build and Operate First Stage of Tseung Kwan O Desalination Plant (TKODP), is a Designated Project under the Environmental Impact Assessment Ordinance (Cap. 499) (EIAO) and is currently governed by a Further Environmental Permit (EP No. FEP - 01/503/2015/ A) for the construction and operation of the Contract.

A2. In accordance with the Environmental Monitoring and Audit (EM&A) Manual for the Contract, EM&A works for marine water quality, noise, waste management and ecology should be carried out by Environmental Team (ET), Acuity Sustainability Consulting Limited (ASCL), during the construction phase of the Contract.

A3. This is the 33rd Monthly EM&A Report, prepared by ASCL, for the Contract summarizing the monitoring results and audit findings of the EM&A programme at and around Tseung Kwan O Area 137 (TKO 137) during the reporting period from 1 November to 30 November 2022.

 

A4. The EM&A programme for this contract has covered environmental monitoring on construction noise level at selected NSRs and Contractor's environmental performance auditing in the aspects of construction dust, construction noise, water quality, waste management, Landscape and Visual and Ecology.

 

SUMMARY OF MAIN WORKS UNDERTAKEN & KEY MITIGATION MEASURES IMPLEMENTED

A5.  Key activities carried out in this reporting period for the Contract included the followings:

 

Product Water Storage Tank Building

-            Resin Injection work & Water Test for 4 Water Tanks

-            Installation of Cat Ladders in 4 Water Tanks and Upper Roof Tiles

-            Underground utility construction

-            Installation of building services, Installation of mechanical equipment, steel pipe

Main Electrical & Central Chiller Plant Building

-            Installation of Upper Roof Tiles

-            Construction of Check Water Meter Cabinet

-            Installation of Metal and Timber Doors

-            Installation of chillers, building services, electrical switchboard

OSCG Building

-            Installation of Design for Manufacturing and Assembly Panel

-            Resin Injection work & Water Test for Brine Tank

-            Construction of Outside Staircases at West Side Ground floor

-            Installation of building services and mechanical equipment


 

Administration Building

-            Construction of interior finishes at 2/F, 3/F, and 4/F

-            carrying out waterproofing works at 1/F open area and Roof

-            Installation of Aluminium Window, tiling works, and louvre

-            Installation of building services, Lifting of electrical switchboard

Reverse Osmosis Building

-           Installation of Design for Manufacturing and Assembly Panels at East & West Sides

-           Construction of Staircases (Inside and Outside Locations)

-           Installation of roof tiles, alum, and louvre

-           Underground utility construction

-           Installation of building services, electrical switchboard, Installation of mechanical equipment, steel pipe, Glass Reinforced Plastics (GRP) pipe

ActiDAFF

-            Installation of R/F Kiosk Metal Doors

-            Water proofing work on roof of Cartridge Filter Plant Room

-            Construction of kiosks and installation of louvre

-            Underground utility construction

-            Scaffolding, installation of mechanical equipment and piping

Inspection corridor

-            Steel fixing works for segment 7, segment 6 and segment 5

-            construction of stair tower

Chemical building

-            Covering the wall opening and waterproofing works at roof of building

-            Underground utility construction

-            Installation of building services, Installation of mechanical equipment

Post Treatment Building

-            Construction of Outside Staircase to Filter Press Room

-            Installation of Aluminium Louvre

-            Underground utility construction

-            Installation of building services, Lifting of lime silo, Installation of mechanical equipment

CO2 Tanks

-            Installation of Fencing and pipes

Outfall Shaft

-            GRP Diffuser Pipe installation

Intake shaft

-            Shafts backfill rock and excavation and lateral support (ELS) removal

Combined Shaft

-            Staircases  and  internal  finishing,  puddle  pipe installation,  stop log wall

construction


 

-            Installation of mechanical equipment and piping, stoplogs and band screens

Pump room

-            Staircases and internal finishing, overhead crane installation

Elevated Walkway

-            Lift shaft construction

Slope works

-            Excavation at slope toe and access erection, Soil anchor and grouting construction

Open Channel

-            Wall construction

Other

-            132 kV temporary emergency vehicular access (eva) Construction

-            Permanent road construction at Zone A, B, C

 

 

A6.    The major environmental impacts brought by the above construction works include:

 

-                 Construction dust and noise generation from construction works, excavation works, rock cutting works and pipe piling driving works

-                 Waste generation from the construction activities; and

-                 Impact on water quality from marine construction works and inland construction works.

A7. The key environmental mitigation measures implemented for the Contract in this reporting period associated with the above construction works include:

 

-                 Dust suppression by regular wetting and water spraying for construction works;

-                 Reduction of noise from equipment and machinery on-site and regular inspection to machinery and plants/vehicles on-site to ensure proper functioning;

-                 Sorting and storage of general refuse and construction waste; and

-                 Deployment of temporary silt curtain in the area where marine construction works were conducted and deployment of water sedimentation tanks for treatment of wastewater at inland and marine areas before discharge.

SUMMARY OF EXCEEDANCE & INVESTIGATION & FOLLOW-UP

 

A8. No noise monitoring was conducted during the reporting period since there are no Contract -related construction activities undertaken within a radius of 300m from the monitoring locations. No exceedance of the Action Level was recorded during the reporting period.

文字方塊: 3A9. The EM&A works for water quality were conducted during the reporting period in accordance with the EM&A Manual.


A10. One hundred and fifty-five (155) of the general water quality monitoring results of suspended solids (SS) obtained had exceeded the Action Level. One hundred and forty­ two (142) of the general water quality monitoring results of SS obtained during the reporting period had exceeded the Limit Level.

A11. Investigation on the reason of exceedance has been carried out, where the exceedances of SS on 5, 8, 10, 12, 15, 17, 19, 22, 24, 26 and 28 November 2022 were concluded to be unrelated to the Contract as detailed in the Incident Reports on Action Level or Limit Level Non-compliance along with supporting materials in Appendix K.

A12. In this reporting period, no landfill gas monitoring was conducted at Wan Po Road (Ch1+513-Ch1+625).

A13. Joint site inspections of the construction work by ET and IEC were carried out on 8, 15, 22 and 29 November 2022 to audit the mitigation measures implementation status. Observations and recommendations were recorded in the site inspection checklists and provided to the contractors together with the appropriate follow-up actions where necessary.

 

COMPLAINT HANDLING AND PROSECUTION

 

A14. No environmental complaint, notification of summons and prosecution was received in the reporting period.

 

REPORTING CHANGE

 

A15. There was no change to be reported that may affect the on-going EM&A programme.

 

SUMMARY OF UPCOMING KEY ISSUES AND KEY MITIGATION MEASURES

 

A16. Key activities anticipated in the next reporting period for the Contract will include the followings:

 

Product Water Storage Tank Building

-            Resin Injection work & Water Test for 4 Water Tanks

-            Installation of Cat Ladders in 4 Water Tanks and Upper Roof Tiles

-            Underground utility construction

-            Installation of building services, Installation of mechanical equipment, steel pipe

Main Electrical & Central Chiller Plant Building

-            Installation of Upper Roof Tiles

-            Construction of Check Water Meter Cabinet

-            Installation of Metal and Timber Doors

-            Installation of chillers, building services, electrical switchboard

OSCG Building

-            Installation of Design for Manufacturing and Assembly Panel

-            Resin Injection work & Water Test for Brine Tank

-            Construction of Outside Staircases at West Side Ground floor

-            Installation of building services and mechanical equipment

 

Administration Building

-            Construction of interior finishes at 2/F, 3/F, and 4/F

-            carrying out waterproofing works at 1/F open area and Roof

-            Installation of Aluminium Window, tiling works, and louvre

-            Installation of building services, Lifting of electrical switchboard

Reverse Osmosis Building

-           Installation of Design for Manufacturing and Assembly Panels at East & West Sides

-           Construction of Staircases (Inside and Outside Locations)

-           Installation of roof tiles, alum, and louvre

-           Underground utility construction

-           Installation of building services, electrical switchboard, Installation of mechanical equipment, steel pipe, Glass Reinforced Plastics (GRP) pipe

ActiDAFF

-            Installation of R/F Kiosk Metal Doors

-            Water proofing work on roof of Cartridge Filter Plant Room

-            Construction of kiosks and installation of louvre

-            Underground utility construction

-            Scaffolding, installation of mechanical equipment and piping

Inspection corridor

-            Steel fixing works for segment 7, segment 6 and segment 5

-            construction of stair tower

Chemical building

-            Covering the wall opening and waterproofing works at roof of building

-            Underground utility construction

-            Installation of building services, Installation of mechanical equipment

Post Treatment Building

-            Construction of Outside Staircase to Filter Press Room

-            Installation of Aluminium Louvre

-            Underground utility construction

-            Installation of building services, Lifting of lime silo, Installation of mechanical equipment

CO2 Tanks

-             Installation of Fencing and pipes

Outfall Shaft

-             GRP Diffuser Pipe installation

Intake shaft

-             Shafts backfill rock and excavation and lateral support (ELS) removal

Combined Shaft


 

-           Staircases and internal finishing, puddle pipe installation, stop log wall construction

-            Installation of mechanical equipment and piping, stoplogs and band screens

Pump room

-           Staircases and internal finishing, overhead crane installation

Elevated Walkway

-            Lift shaft construction

Slope works

-            Excavation at slope toe and access erection, Soil anchor and grouting construction

Open Channel

-           Wall construction

Other

-           132 kV temporary emergency vehicular access (eva) Construction

-            Permanent road construction at Zone A, B, C

 

 

A17. The major environmental impacts brought by the above construction works will include:

 

-                 Construction dust and noise generation from excavation and construction works;

-                 Waste generation from construction activities; and

-                 Impact on water quality from marine construction works and inland construction works.

A18. The key environmental mitigation measures for the Contract in the coming reporting period associated with the above construction works will include:

 

-                 Reduction of noise from equipment and machinery on-site;

-                 Dust suppression by regular wetting and water spraying for construction works and at main haul road;

-                 Sorting and storage of general refuse and construction waste; and

-                 Deployment of temporary silt curtain in the area where marine construction works were conducted and deployment of water sedimentation tanks for treatment of wastewater at inland and marine areas before discharge.

 

 

 

 

 


 

1.             BASIC CONTRACT INFORMATION

 

BACKGROUND

1.1.        The Acciona Agua, S.A. Trading, Jardine Engineering Corporation, Limited and China State Construction Engineering (Hong Kong) Limited as AJC Joint Venture (AJCJV) is contracted to carry out the Design, Build and Operate First Stage of Tseung Kwan O Desalination Plant (DPTKO) under Contract No. 13/WSD/17 (the Contract).

1.2.        Acuity Sustainability Consulting Limited (ASCL) is commissioned by AJCJV to undertake the Environmental Team (ET) services as required and/or implied, both explicitly and implicitly, in the Environmental Permit (EP), Environmental Impact Assessment Report (EIA Report) (Register No. AEIAR-192/2015) and Environmental Monitoring and Audit Manual (EM&A Manual) for the Contract; and to carry out the Environmental Monitoring and Audit (EM&A) programme in fulfillment of the EIA Report's EM&A requirements and Contract No. 13/WSD/17 Specification requirements.

1.3.        Pursuant to the Environmental Impact Assessment Ordinance (EIAO), the Director of Environmental Protection granted the Environmental Permit (No. EP-01/503/2015) and Variation of Environmental Permit (No. EP-01/503/2015/A) to Water Supplies Department (WSD); and granted the Further Environmental Permit (No. FEP- 01/503/2015/A) to AJCJV for the Contract.

 

THE REPORTING SCOPE

1.4.        This is the 33rd Monthly EM&A Report for the Contract which summarizes the key findings of the EM&A programme during the reporting period from 1 November to 30 November 2022.

 

CONTRACT ORGANIZATION

1.5.        The Contract Organization structure for Construction Phase is presented in Figure 1.1.

 


                                                            Figure 1.1       Contract Organization Chart

 

1.6.        Contact details of the key personnel are presented in Table 1.1 below:


                                               

                                                Table 1.1         Contact Details of Key Personnel


 

Party

Position

Name

Telephone no.

Contract Proponent (Water Supplies Department)

SE/CM2

Benny Lam

2634-3573

 

Supervising Officer (Binnies Hong Kong Limited)

Project Manager

 

Christina Ko

 

2608-7302

Chief Resident Engineer

 

Roger Wu

 

6343-1002

 

The Jardine Engineering Corporation, Limited, China State Construction Engineering (Hong Kong) Limited and Acciona Agua, S.A. Trading

Project Manager

Stephen Yeung

 

2807-4665

Environmental Monitoring Manager

 

Brian Kam

 

9456-9541

Acuity Sustainability Consulting Limited

Environmental Team Leader

 

Jacky Leung

 

2698-6833

 

ANewR Consulting Limited

Independent Environmental Checker (IEC)

 

Louis Kwan

 

2618-2831

 

 

SUMMARY OF CONSTRUCTION WORKS

1.7.        Details of the major construction activities undertaken in this reporting period are shown as below. The master programme is presented in Appendix A.

1.8.        Key activities carried out in this reporting period for the Contract included the followings:

 

Product Water Storage Tank Building

-            Resin Injection work & Water Test for 4 Water Tanks

-            Installation of Cat Ladders in 4 Water Tanks and Upper Roof Tiles

-            Underground utility construction

-            Installation of building services, Installation of mechanical equipment, steel pipe

Main Electrical & Central Chiller Plant Building

-            Installation of Upper Roof Tiles

-            Construction of Check Water Meter Cabinet

-            Installation of Metal and Timber Doors

-            Installation of chillers, building services, electrical switchboard

OSCG Building

-            Installation of Design for Manufacturing and Assembly Panel

-            Resin Injection work & Water Test for Brine Tank

-            Construction of Outside Staircases at West Side Ground floor

-            Installation of building services and mechanical equipment


 

 

 

文字方塊: .Administration Building

-            Construction of interior finishes at 2/F, 3/F, and 4/F

-            carrying out waterproofing works at 1/F open area and Roof

-            Installation of Aluminium Window, tiling works, and louvre

-            Installation of building services, Lifting of electrical switchboard

Reverse Osmosis Building

-           Installation of Design for Manufacturing and Assembly Panels at East & West Sides

-           Construction of Staircases (Inside and Outside Locations)

-            Installation of roof tiles, alum, and louvre

-           Underground utility construction

-            Installation of building services, electrical switchboard, Installation of mechanical equipment, steel pipe, Glass Reinforced Plastics (GRP) pipe

ActiDAFF

-            Installation of R/F Kiosk Metal Doors

-            Water proofing work on roof of Cartridge Filter Plant Room

-            Construction of kiosks and installation of louvre

-            Underground utility construction

-            Scaffolding, installation of mechanical equipment and piping

Inspection corridor

-            Steel fixing works for segment 7, segment 6 and segment 5

-            construction of stair tower

Chemical building

-            Covering the wall opening and waterproofing works at roof of building

-            Underground utility construction

-            Installation of building services, Installation of mechanical equipment

Post Treatment Building

-           Construction of Outside Staircase to Filter Press Room

-            Installation of Aluminium Louvre

-           Underground utility construction

-            Installation of building services, Lifting of lime silo, Installation of mechanical equipment

CO2 Tanks

-             Installation of Fencing and pipes

Outfall Shaft

-            GRP Diffuser Pipe installation

Intake shaft

-            Shafts backfill rock and excavation and lateral support (ELS) removal

-              Combined Shaft


 

-           Staircases and internal finishing, puddle pipe installation, stop log wall construction

-            Installation of mechanical equipment and piping, stoplogs and band screens

Pump room

-           Staircases and internal finishing, overhead crane installation

Elevated Walkway

-            Lift shaft construction

Slope works

-            Excavation at slope toe and access erection, Soil anchor and grouting construction

Open Channel

-           Wall construction

Other

-           132 kV temporary emergency vehicular access (eva) Construction

-            Permanent road construction at Zone A, 8, C

 

 

1.9.        A summary of the valid permits, licences, and/or notifications on environmental protection for this Contract is presented in Table 1.2.

 

Table 1.2 Summary of the Status of Valid Environmental Licence, Notification, Permit and Documentations


 


 

1.10.     The status for all environmental aspects is presented in Table 1.3.

 

Table 1.3 Summary of Status for Key Environmental Aspects under the EM&A Manual

 

1.11.    Other than the EM&A work by ET, environmental briefings, trainings, and regular environmental management meetings were conducted, in order to enhance environmental awareness and closely monitor the environmental performance of the contractors.

 

1.12.    The EM&A programme has been implemented in accordance with the recommendations presented in the approved EIA Report and the EM&A Manual. A summary of implementation status of the environmental mitigation measures for the construction phase of the Contract during the reporting period is provided in Appendix C.

 

 

 

 

 

2.              NOISE

 

MONITORING REQUIREMENTS

2.1.       To ensure no adverse noise impact, noise monitoring is recommended to be carried out within 300m radius from the nearby noise sensitive receivers (NSRs), during construction phase. The NSRs selected as monitoring station are (i) NSR4 - Creative Secondary School, (ii) NSR24 - PLK Laws Foundation College, and (iii) NSR31 - School of Continuing and Professional Studies - CUHK respectively.

 

2.2.       Construction noise level were measured in terms of the A-weighted equivalent continuous sound pressure level (LAeq). Leq 30min was used as the monitoring parameter for the time period between 0700 and 1900 on normal weekdays. Construction works would follow stipulations of the valid Construction Noise Permits if works had to be conducted during restricted hours or public holidays. Table 2.1 summarizes the monitoring parameters, frequency, and duration of the impact noise monitoring.

 


Table 2.1  Noise Monitoring Parameters, Time, Frequency and Duration

Time

Duration

Interval

Parameters

 

Daytime:

0700-1900

Daytime:

0700-1900

(during normal

weekdays)

Continuously in

Leq 5min/ Leq 30min (average of 6 consecutive Leq 5min)

 

Leq 3Omm

L10 30min & L90 30mm

 

 
 

 

 

 

 

 

 

 

 

 


MONITORING LOCATIONS

2.3.       The monitoring locations were normally made at a point 1m from the exterior of the NSRs building facade and be at a position 1.2m above the ground. A correction of +3dB(A) should be made to the free-field measurements.

 

2.4.       According to the environmental findings detailed in the EIA report and Baseline Monitoring Report, the designated locations for the construction noise monitoring are listed in Table 2.2 below.

Table 2.2  Noise Sensitive Receivers

 

NSRID

Noise Sensitive Receivers

Monitoring Location

Position

NSR4

Creative Secondary School

Roof Floor

1 m from facade

NSR24

PLK Laws Foundation College

Pedestrian Road on Ground Floor

Free-field

NSR31

School of Continuing and Professional Studies - CUHK

Roof Floor

1 m from facade

                                                                                              

2.5.       Three noise monitoring locations for impact monitoring at the nearby sensitive receivers are shown in Figure 2.1-2.3.

 

Figure 2.1 NSR4 Creative Secondary School

Figure 2.2 NSR24 PLK Laws Foundation College

Figure 2.3 NSR31 School of Continuing and Professional Studies - CUHK

 

 

 

 

IMPACT MONITORING METHODOLOGY

2.6.       Integrated sound level meter will be used for the noise monitoring. The meter will be in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1) specifications. Immediately prior to and following each noise measurement the accuracy of the sound level meter will be checked using an acoustic calibrator generating a known sound pressure level at a known frequency. Measurements will be accepted as valid only if the calibration levels before and after the noise measurements agree to within 1.0 dB(A).

 

2.7.       Noise measurements were not made in the presence of fog, rain, wind with a steady speed exceeding 5 m/s or wind with gusts exceeding 10 m/s. The wind speed shall be checked with a portable wind speed meter capable of measuring the wind speed in m/s.

 

ACTION AND LIMIT LEVELS

2.8.       The Action/Limit Levels are in line with the criteria of Practice Note for Professional Persons (ProPECC PN 2/93) "Noise from Construction Activities - Non-statutory Controls" and Technical Memorandum on Environmental Impact Assessment Process issued by HKSAR Environmental Protection Department ["EPD"] under the Environmental Impact Assessment Ordinance, Cap 499, S.16 are presented in Table 2.3.


Table 2.3        Action and Limit Levels for Noise per EM&A Manual


 

Time Period

Action

Limit (dB(A))

0700-1900 on normal weekdays

When   one   documented

complaint is received from any one of the noise sensitive receivers

-              70 dB(A) for school

and

-              65 dB(A) during examination period

Note: Limits specified in the GW-TM and IND-TM for construction and operation noise, respectively.

 

2.9.        If exceedances were found during noise monitoring, the actions in accordance with the Event and Action Plan shall be carried out according to Appendix E.

 

MONITORING RESULTS AND OBSERVATIONS

2.10.   Referring to EM&A Manual Section 4.1.2, the impact noise monitoring should be carried out when there are Contract-related construction activities undertaken within a radius of 300m from the monitoring stations. No monitoring station was located within a radius of 300m of the Contract site as shown in Figure 2.4, no impact noise monitoring was conducted in the reporting period.


Figure 2.4    Site Layout Plan with Noise Sensitive Receivers and Desalination Plant

 

 

 

 

 


 

3.              WATER QUALITY

 

3.1.       In accordance with the recommendations of the EIA, water quality monitoring is required during dredging for the submarine pipelines and, during operation phase. The following Section provides details of the water quality monitoring to be undertaken by the Environmental Team (ET) to verify the distance of sediment and brine plume dispersion and to identify whether the potential exists for any indirect impacts to occur to ecological sensitive receivers.

3.2.       The water quality monitoring programme will be carried out to allow any deteriorating water quality to be readily detected and timely action taken to rectify the situation.

3.3.       Water quality monitoring for the Contract can be divided into the following stages:

-              Dredging activities during construction phase;

-              Discharge of effluent from main disinfection during construction phase;

WATER QUALITY PARAMETERS

3.4.       The parameters that have been selected for measurement in situ and in the laboratory are those that were either determined in the EIA to be those with the most potential to be affected by the construction works or are a standard check on water quality conditions. Parameters to be measured in the impact monitoring are listed in Table 3.1.

Table 3.1         Parameters measured in the Impact Marine Water Quality Monitoring

 

Parameters

Unit

Abbreviation

In-situ measurements

Dissolved oxygen

mg/L

DO

Temperature

oC

-

pH

-

-

Turbidity

NTU

-

Salinity

0/00

-

Total Residual Chlorine NOTE1

mg/L

TRC

Laboratory measurements

Suspended Solids

mg/L

SS

Iron-Soluble

mg/L

Fe

Anti-sealant as Reactive Phosphorus

mg/L

PO4 as P-



NOTE 1: Monitoring of Total Residual Chlorine will be conducted when cleaning and sterilization of the new freshwater main is carried out.

 

3.5.       In addition to the water quality parameters, other relevant data were also being measured and recorded in Water Quality Monitoring Logs, including the location of the sampling stations, water depth, time, weather conditions, sea conditions, tidal stage, current direction and velocity, special phenomena and work activities undertaken around the monitoring and works area that may influence the monitoring results.


 

MONITORING EQUIPMENT

3.6.        For water quality monitoring, the following equipment were used:

 

Dissolved Oxygen and Temperature Measuring Equipment - The instrument was a portable, weatherproof dissolved oxygen measuring instrument complete with cable, sensor, comprehensive operation manuals, and was operable from a DC power source. It was capable of measuring: dissolved oxygen levels in the range of 0 - 20 mg/L and 0 - 200% saturation; and a temperature of 0 - 45 degrees Celsius. It has a membrane electrode with automatic temperature compensation complete with a cable of not less than 35 m in length. Sufficient stocks of spare electrodes and cables were available for replacement where necessary (e.g. YSI model 59 DO meter, YSI 5739 probe, YSI 5795A submersible stirrer with reel and cable or an approved similar instrument).

 

Turbidity Measurement Equipment - The instrument was a portable, weatherproof turbidity-measuring unit complete with cable, sensor and comprehensive operation manuals. The equipment was operated from a DC power source, it has a photoelectric sensor capable of measuring turbidity between 0 - 1000 NTU and complete with a cable with at least 35 min length (for example Hach 2100P or an approved similar instrument).

 

Salinity Measurement Instrument - A portable salinometer capable of measuring salinity in the range of 0 - 40 ppt was provided for measuring salinity of the water at each monitoring location.

 

Water Depth Gauge - A portable, battery-operated echo sounder (for example Seafarer 700 or a similar approved instrument) was used for the determination of water depth at each designated monitoring station. This unit will preferably be affixed to the bottom of the work boat if the same vessel is to be used throughout the monitoring programme. The echo sounder was suitably calibrated.

 

Positioning Device - A Global Positioning System (GPS) was used during monitoring to allow accurate recording of the position of the monitoring vessel before taking measurements. The Differential GPS, or equivalent instrument, was suitably calibrated at appropriate checkpoint (e.g. Quarry Bay Survey Nail) to verify that the monitoring station is at the correct position before the water quality monitoring commence.

 

Water Sampling Equipment - 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, was used. The water sampler has 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.

 

SAMPLING / TESTING PROTOCOLS

3.7.       All in situ monitoring instruments were checked, calibrated, and certified by a laboratory accredited under HOKLAS or any other international accreditation scheme before use, and subsequently re-calibrated at monthly intervals throughout the stages of the water quality monitoring. Responses of sensors and electrodes were checked with certified standard solutions before each use.

 


3.8.       Table 3.2 summarizes the equipment used in the water quality monitoring program. The copies of the calibration certification of multi-parameter water quality system are shown in the Appendix F.

 


Table 3.2 Water Quality Monitoring Equipment

Model & Make

Serial Number

Calibration

Qty.

 

Water Sampler

Kahlsico Water Sampler 13SWB20

-

-

1

 

Multi-parameter Water Quality System

HORIBA U-53

PORBNFNT

12 Oct 2022

2

 

PPHNOMXY

16 Nov 2022

 

 

3.9.       On-site calibration of field equipment was following the "Guide to On-Site Test Methods for the Analysis of Waters", BS 1427: 2009. Sufficient stocks of spare parts were maintained for replacements when necessary. Backup monitoring equipment was made available so that monitoring can proceed uninterrupted even when equipment is under maintenance, calibration etc.

 

LABORATORY MEASUREMENT AND ANALYSIS

3.10.   Sufficient volume of each water sample was collected for carrying out the laboratory analyses. Using chain of custody forms, collected water samples were transferred to a HO KLAS accredited laboratory (Acumen Laboratory and Testing Limit - HOKLAS 241) for immediate processing. The determination work was start within the next working day after collection of the water samples. Analytical methodology and sample preservation of other parameters were based on the latest edition of Standard Methods for the Examination of Waste and Wastewater published by APHA, AWWA and WPCF and methods by USEPA, or suitable method in accordance with requirements of HOKLAS or another internationally accredited scheme. The QA/QC details were in accordance with requirements of HOKLAS or another internationally accredited scheme.

 

3.11.    Parameters for laboratory measurements, standard methods and detection limits are presented in Table 3.3.

 

Table 3.3   Laboratory measurements, standard methods, and corresponding detection limits of marine water quality monitoring

 

Parameters

Standard Methods

Detection Limit

Reporting Limit

Precision

Dissolved oxygen

Instrumental, CTD

0.1

-

+-25%

Temperature

Instrumental, CTD

0.1

-

+-25%

pH

Instrumental, CTD

0.1

-

+-25%

Turbidity

Instrumental, CTD

0.1

-

+-25%

Salinity

Instrumental, CTD

0.1

-

+-25%

Suspended Solids

APHA 23rd Ed 2540D

1.0

2.5

+-17%

 


 

MONITORING LOCATION

3.12.   The Impact water quality monitoring locations are in accordance with the EM&A Manual and detailed in Table 3.4 below. A schedule for water quality monitoring was prepared by the ET and submitted to IEC and EPD prior to the commencement of the monitoring.

 

Table 3.4         Location of Impact Water Quality Monitoring Stations

 

Station

Easting

Northing

Description

CE

843550

815243

Upstream control station at ebb tide

CF

846843

810193

Upstream control station at flood tide

WSR1

846864

812014

Ecological sensitive receiver at Tung Lung Chau

WSR2

847645

812993

Fisheries sensitive receiver at Tung Lung Chau

WSR3

848023

813262

Ecological sensitive receiver at Tung Lung Chau

WSR4

847886

814154

Ecological sensitive receiver at Tai Miu Wan

WSR16

845039

815287

Ecological sensitive receiver at Fat Tong Chau

WSR33

847159

814488

Ecological sensitive receiver at Tai Miu Wan

WSR36

846878

814081

Ecological sensitive receiver at Kwun Tsai

WSR37

846655

813810

Ecological sensitive receiver at Tit Cham Chau

NF1

846542

813614

Edge of mixing zone, ~ 200m west of outfall diffuser

NF2

846942

813614

Edge of mixing zone, ~ 200m east of outfall diffuser

NF3

846742

813414

Edge of mixing zone, ~ 200m south of outfall diffuser

 

 

3.13.   WSR1 to WSR37 were identified in accordance with Annex 14 of the EIAO-TM as well as Clause 3.4.4.2 of the Environmental Impact Assessment Study Brief for Desalination Plant at Tseung Kwan O (No. ESB-266/2013). WSR1 to WSR3 are sited near the Tung Lung Chau Fish Culture Zone; WSR16 and WSR36 are sited near the coral assemblages along the coastlines of Fat Tong Chau and Kwun Tsai respectively; WSR 4 and WSR33 are sited near the Coastal Protection Area and coral assemblages in waters of Tai Miu Wan; WSR37 is sited near the fisheries resource including spawning and nursery grounds at the coastal water of Tit Cham Chau.


 

 

Figure 3.1       Impact water quality monitoring locations under EM&A Manual

 

SAMPLING FREQUENCY

3.14.   Impact water quality monitoring were carried out three days per week during the construction phase after the commencement of marine construction works and dredging activities. Monitoring at each station was undertaken at both mid-ebb and mid-flood tides on the same day. The tidal range selected for the impact monitoring was at least 0.5 m for both flood and ebb tides as far as practicable. The interval between two sets of monitoring was not less than 36 hours. The monitoring frequency would be increased in the case of exceedances of Action/Limit Levels if considered necessary by ET. Monitoring frequency would be maintained as far as practicable.

 

SAMPLING DEPTHS & REPLICATION

3.15.   During impact water quality monitoring, each station was sampled, and measurements/ water samples was taken at three depths, 1 m below the sea surface, mid-depth, and 1 m above the seabed. For in situ measurements, duplicate readings were made at each water depth at each station. Duplicate water samples were collected at each water depth at each station. All water quality monitoring results were summarized in Appendix G.

 

ACTION AND LIMIT LEVELS

3.16.   The Action and Limit Levels have been set based on the derivation criteria specified in the EM&A Manual. The Action/Limit Levels have been derived and are presented in Table 3.5.


Parameters

Action

Limit

Construction Phase Impact Monitoring

DO in mg/L

Surface and Middle

7.30 mg L-1

Surface and Middle

4 mg L-1

 

Bottom

7.31 mg L-1

Bottom

2 mg L-1

 

Tung Lung Chau Fish Culture Zone

Tung Lung Chau Fish Culture Zone

 

5.1 mgL-1

or

level  at

control

5.0 mgL-1 or

level  at

control

 

station (Whichever the lower)

station (Whichever the lower)

SS    in     mg/L

5.00 mg L-1 or 20% exceedance of

6.00 mg L-1 or 30% exceedance of

(Depth­

value    at

any

impact

station

value    at    any

impact

station

averaged)

compared    with    corresponding

compared    with    corresponding

 

data from control station

data from control station

Turbidity       in

2.41 NTU or 20% exceedance of

2.84 NTU or 30% exceedance of

NTU     (Depth-

value    at

any

impact

station

value    at    any

impact

station

averaged)

compared    with    corresponding

compared    with    corresponding

 

data from control station

data from control station

 

 
                                    Table 3.5         Derived Action and Limit Levels for Water Quality

Notes:

i. "Depth-averaged" is calculated by taking the arithmetic means of reading of all three depths

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

iii. For Turbidity, SS, iron and Salinity, non-compliance of the water quality limits occurs when monitoring result is higher than the limits.

 

MONITORING RESULTS AND OBSERVATIONS

3.17.   General water quality monitoring at the ten monitoring stations (CE, CF, WSRl, WSR2, WSR3, WSR4, WSR16, WSR33, WSR36 and WSR37) were conducted 1, 3, 5, 8, 10, 12, 15, 17, 19, 22, 24, 26 and 28 November 2022.

 

3.18.   One hundred and fifty-five (155) of the general water quality monitoring results of suspended solids (SS) obtained had exceeded the Action Level. One hundred and forty­ two (142) of the general water quality monitoring results of SS obtained during the reporting period had exceeded the Limit Level.

3.19.   Investigation on the reason of exceedance has been carried out, where the exceedances of SS on 5, 8, 10, 12, 15, 17, 19, 22, 24, 26 and 28 November 2022 were concluded to be unrelated to the Contract as detailed in the Incident Reports on Action Level or Limit Level Non-compliance along with supporting materials in Appendix K.

3.20.   Monitoring results of 6 key parameters: Salinity, DO, turbidity, SS, pH, and temperature in this reporting, are summarized in Table 3.6 and Table 3.7, and detailed results are presented in Appendix L.


 

Table 3.6            Summary of Impact Water Quality Monitoring Results (Mid-Flood)

 

Locations

Parameters

Salinity

(ppt)

Dissolved Oxygen

(mg/L)

pH pH

Turbidity (NTU)

Suspended

Solids (mg/L)

Temp.(°C)

Surface & Middle

 

Bottom

 

CE

Avg.

32.9

9.6

9.6

8.3

2.8

7.1

24.8

Min.

31.6

9.6

9.6

8.2

2.4

2.5

21.5

Max.

34.0

9.7

9.6

8.4

3.6

19.0

25.7

CF

Avg.

33.0

8.8

8.8

8.3

3.1

8.8

25.0

 

Min.

32.1

8.3

8.3

8.2

2.0

2.5

24.4

 

Max.

34.0

9.6

9.5

8.4

3.9

23.0

25.7

 

WSRl

Avg.

32.9

8.8

8.8

8.3

2.3

10.1

25.2

Min.

31.4

8.4

8.3

8.0

1.8

2.5

24.5

Max.

33.8

9.4

9.5

8.4

2.7

20.0

26.0

 

WSR2

Avg.

32.7

8.9

8.9

8.3

2.1

8.5

25.1

Min.

31.4

8.3

8.2

8.2

1.6

2.5

24.1

Max.

33.7

9.5

9.5

8.4

2.5

24.0

25.9

 

WSR3

Avg.

32.7

8.9

8.9

8.2

2.3

10.8

25.1

Min.

31.1

8.3

8.3

8.1

2.0

2.5

24.4

Max.

34.0

9.6

9.6

8.4

2.9

32.0

25.9

WSR4 j

Avg.

32.8

8.8

8.8

8.3

2.3

10.6

25.0

Min.

31.5

8.0

8.0

8.1

1.9

2.5

24.3

Max.

34.1

9.3

9.4

8.4

2.7

23.0

25.9

WSR16 j

Avg.

32.9

8.9

8.9

8.2

2.2

10.5

25.1

Min.

31.8

8.3

8.2

8.1

1.9

2.5

24.5

Max.

33.9

9.3

9.5

8.4

2.5

23.0

26.0

WSR33 j

Avg.

32.9

8.8

8.8

8.2

2.3

9.0

25.1

Min.

31.5

8.3

8.3

8.1

1.8

2.5

24.1

Max.

34.0

9.2

9.2

8.4

3.0

22.0

25.9

WSR36 j

Avg.

32.7

8.8

8.8

8.3

2.3

9.1

25.1

Min.

31.8

8.3

8.3

8.1

2.0

2.5

24.2

Max.

34.0

9.4

9.4

8.4

2.7