Revision History

Rev.

Description of Modification

Date

1.

First Issue for Comments

05/04/2024

2

Revise according to comment

11/04/2024

3

Revise according to comment

12/04/2024

 

 

 

 

 


CONTENTS

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

1.          Basic Contract Information............................................................................................................................... 8

2.          Noise........................................................................................................................................................................ 14

3.          Water Quality....................................................................................................................................................... 18

4.          Waste....................................................................................................................................................................... 29

5.          Landfill Gas Monitoring................................................................................................................................... 30

6.          Ecology(Landscape).......................................................................................................................................... 34

7.          Ecology (Coral Monitoring)............................................................................................................................ 35

8.          Ecology (Fishery Monitoring)....................................................................................................................... 37

9.          Summary of Exceedance, Complaints, Notification of Summons and Prosecutions.............. 40

10.      EM&A Site Inspection....................................................................................................................................... 42

11.      Future Key Issues............................................................................................................................................... 43

12.      Conclusions and Recommendations.......................................................................................................... 46

 

 

Appendix A                           Master Programme

 

Appendix B                           Overview of Desalination Plant in Tseung Kwan O

 

Appendix C                           Summary of Implementation Status of Environmental Mitigation

Appendix D                          Impact Monitoring Schedule

Appendix E                           Event/Action Plan

 

Appendix F                           Water Quality Monitoring Equipment and Landfill Gas Equipment Calibration Certificate

Appendix G                          Water Quality Monitoring Data and Landfill Gas Monitoring Data

Appendix H                          Waste Flow Table

Appendix I                            Ecology (Coral & Fishery) Survey Report

 

Appendix J                            Site Inspection Proforma

 

Appendix K                           Complaint Log

 

Appendix L                           Exceedance Report

 

 

 

 

 


Executive Summary

 

Introduction

 

A1. 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 49th 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 March to 31 March 2024.

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:

 

Administration Building

-            Installation of Internal partition wall

-            External wall finishing works

-            Construction of block work for meter cabinet

-            Installation of glass door for laboratory

-            Minor Installation of building services, cable laying and termination, Photovoltaic Panel Installation, Testing & Commissioning

Chemical building

-            Roof planting works

-            Construction of hose reel cabinet.

-            Defect rectification

Main Electrical & Central Chiller Plant Building

-            Minor Installation of building services, electrical switchboard, cable laying, pressure test

ActiDAFF

-            Underground utility construction work

-            Rectification works for roof tiles


 

-            Minor Installation of mechanical equipment, installation of building services, Minor cable laying and termination, Installation of Lightning System, Installation of Fibre Reinforced Polymer Cover Installation, Testing & Commissioning

Product Water Storage Tank Building

-            Waterproofing work at Roof Slab on Tank A

-            Tank A defect rectification, Water proofing,

-            Installation of building services, cable laying and termination, Testing & Commissioning

-            Underground utility construction work (Sewerage and Waterworks) -

OSCG Building

-             Installation of Promat Board in Skid Room

-             Installation of Railing on Brine Maker Tank

-             Installation of building services, mechanical equipment and cable laying and termination, testing and commissioning

Reverse Osmosis Building

-            Sanitary Ware Installation in Toilet

-            Wall Painting and False Ceiling Installation in Toilet

-            Installation of Water Meter Cabinets

-            Construction of External Concrete Walls

-            Underground utility construction work

-            Installation of building services, electrical switchboard of cable laying and termination, Minor Installation of mechanical equipment and raised floor, testing and commissioning, Photovoltaic Panel Installation

Post Treatment Building

-            Installation of Cat Ladders in Irrigation Tanks

-            Placing Soil Mix at Roof

-            Curb Construction for Rescue Opening at Water Tanks

-            Minor Installation of building services, Minor Installation of mechanical equipment, Cable laying and termination, Pressure Test

Inspection corridor

-            Construction of roof tiling

-            Internal decoration and finishing works

-            Installation of building services, Lift Installation


 

Combined Shaft and Pump room

-              CCTV Installation, Installation of Lightning System, Minor building services Installation, testing and commissioning

-              Internal finishing, defect rectification Guard House

-            Installation of Building Services

-            Guard House B Guard House, Workshop construction work Other

-            Underground utility rectification work (Manhole and Draw pit) -

-            Watermain installation works at CLP 132 Kv Substation

-            Security Fence footing construction work

-            Light Pole installation work

-            Road Construction

-            Footpath Construction

-            Landscape Construction

-            Irrigation System installation

-             Water Pressure Test for Fire Services and Plumbing System

-             Landscape planting work

-             Traffic signage work

-             Cladding installation for Elevated Walkway

-             Slope work -Rock anchors installation, Rock break, Concreting

-             Open Channel and Wave deflector Wall

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

 

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

-                 Waste generation from the construction activities

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;

-                 Deployment of silt curtain at the inshore water outflow;

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

-                 Deployment protective fencing for trees

 

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.

A9.  The construction phase marine water quality programme was ceased from 1 September 2023 due to the completion of marine-related construction works.

A10. The EM&A works for Pre-operation phase marine water quality were conducted during the reporting period in accordance with the EM&A Manual. Forty (40) of the pre- operation phase water quality monitoring results of SS obtained had exceeded the Action Level. Twenty-seven (27) of the pre-operation phase water quality monitoring results of SS obtained during the reporting period had exceeded the Limit Level.

A11. Water quality monitoring of the discharge of dechlorinated effluent in disinfection procedure is completed in December 2023. The hourly dechlorinated effluent monitoring during the discharge is finished.

A12. Pre-operation phase coral monitoring works was conducted on 26 March 2024. No sediment, bleaching or increased mortality in the general condition of all tagged coral colonies were observed during the monthly pre-operation phase monitoring period. No deterioration of the coral community was observed in the ecological monitoring results when compared with the baseline ecological monitoring results. There is no AL/LL exceedance during the monitoring period.

A13. Pre-operation phase fishery monitoring for dry season was carried out on 17 and 24 February 2024. The detail of the monitoring would be present when the result is available.

A14. In this reporting period, 120 times of landfill gas monitoring were periodically conducted at TKO Area 137 (Ch1+340 - Ch1+600). No exceedances of action level and limit level was observed.

A15. Joint site inspections of the construction work by ET and IEC were carried out on 19 and 25 March 2024 to audit the mitigation measures implementation status. Reminders 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

 

A16. No environmental complaint, notification of summons and prosecution was received in the reporting period.

Reporting Change

 

A17. 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

 

A18. Key activities anticipated in the next reporting period for the Contract will include the followings:


 

Administration Building

-            Installation of signage

-            Installation of ceiling

-            Painting works

-            Installation of sanitary fitting

-            Installation of vinyl flooring

-            Installation of Aluminium Fins

-            Installation of Internal partition wall and ceiling

-            External wall finishing works

-            Installation of AP doors and cat ladders

-            Installation of wood decking

-            Minor Installation of building services, cable laying and termination, Photovoltaic Panel Installation, Testing & Commissioning

Chemical building

-            Roof planting works

-            Defect rectification

Main Electrical & Central Chiller Plant Building

-            Minor Installation of building services, electrical switchboard, cable laying, pressure test

-            Ladder and Cover installation at Roof

ActiDAFF

-            Rectification works for roof tiles

-            Installation of signage

-            Minor Installation of mechanical equipment, building services, minor cable laying and termination, Installation of Fibre Reinforced Polymer Cover, Testing & Commissioning

Product Water Storage Tank Building

-            Installation of signage

-            Installation of cladding works

-            Tiling work at Roof Slab on Tank A

-            Ladder and Cover installation at Roof

-            Roof Tiles installation

-            Minor Installation of building services, cable laying and termination, Testing & Commissioning

OSCG Building

-             Installation of Promat Board in Skid Room

-             Installation of cladding works

-             Installation of Railing on Brine Maker Tank

-             Installation of building services, mechanical equipment and cable laying and termination, testing and commissioning


 

Reverse Osmosis Building

-            Installation of AP doors

-            Installation of sanitary fitting

-            Sanitary Ware Installation in Toilet

-            Tiling Work in Toilet

-            Installation of Water Meter Cabinets

-            Installation of building services, electrical switchboard of cable laying and termination, Minor Installation of mechanical equipment and raised floor, testing and commissioning, Photovoltaic Panel Installation

Post Treatment Building

-            Installation of Cat Ladders in Irrigation Tanks

-            Green Roof

-            Minor Installation of building services, Minor Installation of mechanical equipment, Cable laying and termination, Pressure Test

Inspection corridor

-            Installation of cat ladder

-            Internal decoration and finishing works

Combined Shaft and Pump room

-              Minor cable laying and termination, testing and commissioning

-              Defect rectification Guard House

-              Installation of Building Services, testing and commissioning Slope Work

-              Rock Dowel Installation

-              Buttress Construction

-              Wire Mesh Laying

-              Drilling; Rock anchors installation, Rock break, Concreting Other

-            Watermain installation works at CLP 132 Kv Substation

-             Underground utility rectification work for Manhole and Draw pit

-             Underground utility Construction Work for Watermain water

-             Underground utility repair Work for Sewerage, Watermains work)

-             Security Fence footing construction work

-             Light Pole installation work

-             Road Construction

-             Footpath Construction

-             Landscape Construction

-             Irrigation System installation

-             Water Pressure Test for Fire Services and Plumbing System

-             Landscape planting work

-             Traffic signage work


 

-             Workshop construction

-             Cladding installation for Elevated Walkway

-             Wave deflector Wall

A19.  The major environmental impacts brought by the above construction works will include:

 

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

-                 Waste generation from construction activities.

A20. 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;

-                 Deployment of silt curtain at the inshore water outflow; and

-                 Deployment protective fencing for trees.

 

 

 

 

 

 

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 49th Monthly EM&A Report for the Contract which summarizes the key findings of the EM&A programme during the reporting period from 1 March to 31 March 2024.

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

 

Milton Law

 

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

Environmental Monitoring Manager

 

Joy Chan

 

6468-1782

Acuity Sustainability Consulting Limited

Environmental Team Leader

Jacky Leung

2698-6833

Lam Environmental Services Limited

Independent Environmental Checker (IEC)

 

Serena Shek

 

6149-6683

 

Summary of Construction Works

1.7.         Details of the major construction activities undertaken in this reporting period are shown 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:

 

Administration Building

-            Installation of Internal partition wall

-            External wall finishing works

-            Construction of block work for meter cabinet

-            Installation of glass door for laboratory

-            Minor Installation of building services, cable laying and termination, Photovoltaic Panel Installation, Testing & Commissioning

Chemical building

-            Roof planting works

-            Construction of hose reel cabinet.

-            Defect rectification


 

Main Electrical & Central Chiller Plant Building

-            Minor Installation of building services, electrical switchboard, cable laying, pressure test

ActiDAFF

-            Underground utility construction work

-            Rectification works for roof tiles

-            Minor Installation of mechanical equipment, installation of building services,

Minor cable laying and termination, Installation of Lightning System, Installation of Fibre Reinforced Polymer Cover Installation, Testing & Commissioning

Product Water Storage Tank Building

-            Waterproofing work at Roof Slab on Tank A

-            Tank A defect rectification, Water proofing,

-            Installation of building services, cable laying and termination, Testing & Commissioning

-            Underground utility construction work (Sewerage and Waterworks) -

OSCG Building

-             Installation of Promat Board in Skid Room

-             Installation of Railing on Brine Maker Tank

-             Installation of building services, mechanical equipment and cable laying and termination, testing and commissioning

Reverse Osmosis Building

-            Sanitary Ware Installation in Toilet

-            Wall Painting and False Ceiling Installation in Toilet

-            Installation of Water Meter Cabinets

-            Construction of External Concrete Walls

-            Underground utility construction work

-            Installation of building services, electrical switchboard of cable laying and termination, Minor Installation of mechanical equipment and raised floor, testing and commissioning, Photovoltaic Panel Installation

Post Treatment Building

-           Installation of Cat Ladders in Irrigation Tanks

-           Placing Soil Mix at Roof

-           Curb Construction for Rescue Opening at Water Tanks

-           Minor Installation of building services, Minor Installation of mechanical equipment, Cable laying and termination, Pressure Test

Inspection corridor

-            Construction of roof tiling

-            Internal decoration and finishing works

-            Installation of building services, Lift Installation


 

Combined Shaft and Pump room

-              CCTV Installation, Installation of Lightning System, Minor building services Installation, testing and commissioning

-              Internal finishing, defect rectification Guard House

-            Installation of Building Services

-            Guard House B Guard House, Workshop construction work Other

-            Underground utility rectification work (Manhole and Draw pit) -

-            Watermain installation works at CLP 132 Kv Substation

-            Security Fence footing construction work

-            Light Pole installation work

-            Road Construction

-            Footpath Construction

-            Landscape Construction

-            Irrigation System installation

-             Water Pressure Test for Fire Services and Plumbing System

-             Landscape planting work

-             Traffic signage work

-             Cladding installation for Elevated Walkway

-             Slope work -Rock anchors installation, Rock break, Concreting

-             Open Channel and Wave deflector Wall

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

 

 

Permit/ Licences

Valid Period

 

Status

 

Remark

From

To

Environmental Permit

EP-503/2015/A

Throughout the Contract

Valid

-

FEP - 01/503/2015/A

Throughout the Contract

Valid

-

Notification of Construction Works under the Air Pollution Control (Construction Dust) Regulation (Form NA)

451539

Throughout the Contract

Valid

-

Billing Account for Disposal of Construction Waste

7036276

Throughout the Contract

Valid

-

Sludge (Special Waste) Disposal (Admission Ticket)


 

 

Permit/ Licences

Valid Period

 

Status

 

Remark

From

To

17674

04/01/2024

30/06/2024

Valid

-

Chemical Waste Producer Registration

5213-839-A2987-01

Throughout the Contract

Valid

-

Wastewater Discharge Licence (Land and Marine works)

WT00035775-2020

23/08/2021

31/07/2025

Valid

-

 

 

 

WT00044188-2023

 

 

 

16/06/2023

 

 

 

30/06/2028

 

 

 

Valid

-   For Plant T&C and operation.

-   Variation of sampling point for the Discharge Licence Part 1 is

under application.

Construction Noise Permit

GW-RE1514-23

22/12/2023

21/06/2024

Valid

-

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

Parameters

Status

Water Quality

Baseline      Monitoring      under      EM&A Manual

The baseline water quality monitoring was conducted between 12 May 2020 to 6 Jun

2020.

Construction Phase Impact Monitoring

Ceased from 1 September 2023

Pre-operation phase Marine Impact Monitoring

On-going

Impact Monitoring of Effluent Discharge from Main Disinfection

Completed

Noise

 

Baseline Monitoring

The baseline noise monitoring result has been reported in Baseline Monitoring Report

and submitted to EPD under EP Condition 3.4

Impact Monitoring

Completed

Waste Management

Mitigation         Measures         in        Waste Management Plan

On-going

Landfill Gas


 

Parameters

Status

Regular Monitoring when construction works are within the 250 m Consultation Zone

 

On-going

Ecology (Coral)

Pre-operation     phase     Regular     Coral Monitoring (Monthly)

On-going

Ecology (Fishery)

Pre-operation phase Regular Fishery Monitoring (Seasonally)

On-going

Ecology (Landscape)

Pre-operation phase Landscape and Visual Site Inspection

On-going

Environmental Audit

Site Inspection covering Measures of Air Quality, Noise Impact, Water Quality, Waste,  Ecological  Quality,  Fisheries,

Landscape and Visual

 

On-going

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 and the Pre-operation 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

Day time: 0700-1900

(during normal weekdays)

Continuously in

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

 

Leq 30min

L10 30min & L90 30min

 

Monitoring Locations

2.3.         The monitoring locations were normally made at a point 1m from the exterior of the NSRs building façade 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

 

NSR ID

Noise Sensitive Receivers

Monitoring Location

Position

NSR 4

Creative Secondary School

Roof Floor

1 m from facade

NSR 24

PLK Laws Foundation College

Pedestrian Road on Ground Floor

Free-field

NSR 31

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. As no Contract-related construction activities were undertaken in the reporting month within a radius of 300m from the monitoring stations 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 was 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; and

-               Operation activities during Pre-operation 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-scalant 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 m in 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.

Total Residual Chlorine -Total residual chlorine (TRC) shall be measured in-situ using approved test kit.

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.         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

3.9.         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 HOKLAS 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 the requirements of HOKLAS or another internationally accredited scheme.

3.10.     Parameters for laboratory measurements, standard methods and detection limits are presented in Table 3.2.

Table 3.2           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%

Iron

APHA 3111 B

0.2

-

+-25%

Total residual chlorine

Test Kit (Lovibond MD200)

Lowest limit = 0.01mg/L;

Upper limit = 6 mg/L

 

-

 

+-25%

 

Monitoring Location

Construction Phase

3.11.     The Impact water quality monitoring was ceased from 1 September 2023 due to the completion of marine-related construction works.


Pre-operation phase

3.12.     The pre-operation phase impact water quality monitoring locations are in accordance with the EM&A Manual and detailed in Table 3.3 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 3.3            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. NF1 to NF3 are the Edge of Mixing zone.


 

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

 

 

Sampling Frequency

Pre-operation phase

3.14.     Impact water quality monitoring were carried out three days per week during the commission phase. Monitoring at each station was undertaken once per day. 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 were 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.

Action and Limit Levels

Pre-operation phase

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 3.4.


Table 3.4           Derived Action and Limit Levels for Water Quality

Parameters

Action

Limit

Pre-operation phase Impact Monitoring

DO in mg/L

Surface and Middle

7.30 mg L-1

Bottom

7.31 mg L-1

Tung Lung Chau Fish Culture Zone

5.1 mgL-1 or level at control station (Whichever the lower)

Surface and Middle 4 mg L-1

Bottom 2 mg L-1

Tung Lung Chau Fish Culture Zone

5.0 mgL-1 or level at control station (Whichever the lower)

SS in mg/L (Depth- averaged)

5.00 mg L-1 or 20% exceedance of value at any impact station compared with corresponding data from control station

6.00 mg L-1 or 30% exceedance of value at any impact station compared with corresponding data from control