Revision History

Rev.

Description of Modification

Date

1.

First Issue for Comments

22/03/2024

2.

Revisd according Comments

27/03/2024

3.

Revisd according Comments

28/03/2024

4

Revisd according Comments

02/04/2024


CONTENTS

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

      Basic Project Information............................................................................................................................................ 6

      Noise................................................................................................................................................................................... 13

       Water Quality.................................................................................................................................................................. 17

      Waste.................................................................................................................................................................................. 26

       Landfill Gas Monitoring.............................................................................................................................................. 27

      Summary of Monitoring Exceedance, Complaints, Notification of Summons and Prosecutions31

     EM&A Site Inspection.................................................................................................................................................. 33

      Conclusions and Recommendations..................................................................................................................... 34

 

 

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                 Water Quality Monitoring Graphical Presentation

Appendix E                 Summary of Exceedances

Appendix F                 Waste Flow Table

Appendix G                 Complaint Log

 

Appendix H                 Event/Action Plan for Water Quality Monitoring

Appendix I                  Event/Action Plan for Construction Noise Exceedance

Appendix J                  Event/Action Plan for Coral Monitoring Exceedance

 

 

 

 

 


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 16th Quarterly 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 December 2023 to 29 February 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 Project included the followings:

Administration Building

-            Carrying out the floor tiles works at G/F

-            External wall painting works

-            Construction of block work for pipe duct

-            Installation of building services, cable laying, electrical switchboard, testing and commissioning

Chemical building

-            Installation of leakage collection pit cover

-            Underground utility construction work

-            Landscape work at roof

-            Defect rectification

Main Electrical & Central Chiller Plant Building

-            Installation of chillers, building services, electrical switchboard and cable laying

-            Installation of Roof Tile for Fuel Tank Room


 

ActiDAFF

-            Underground utility construction work

-            Installation of access opening cover

-            Construction of staircase no 2

-            Installation of mechanical equipment, piping system, installation of building services, electrical switchboards and cable laying, fiber-reinforced plastic cover Installation

Product Water Storage Tank Building

-            Installation of Cat Ladders in Water Tank A

-            Sealing slab opening in water Tank A

-            Re-construction of Wall PW8 in Water Tank A

-            Installation of metal cladding, building services, cable laying, mechanical equipment, steel pipe

-            Underground utility construction

OSCG Building

-             Protective Coating for dangerous goods Rooms

-             Placing Soil Mix at Roof

-             Installation of Metal Cladding (at East Side) and Roller Shutters and Window

-            Underground utility construction work

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

Reverse Osmosis Building

-           Installation of building services, electrical switchboard, cable laying, Installation of mechanical equipment, steel pipe, Glass Reinforced Plastic pipe, raised floor, testing and commissioning

-           Installation of metal cladding, handrailing, roller shutters, glass canopy and

glass house

-           Underground utility construction work

-           Construction of Reinforced Concrete External Wall for Male Toilet

Post Treatment Building

-           Installation of building services, Installation of mechanical equipment and piping system, Pressure Test

-           Underground utility construction work

-           Installation of Cat Ladders in Water Tanks

-           Installation of Metal Cladding

-           Placing Soil Mix at Roof

Inspection corridor

-            Installation of building services, Lift installation

-            Construction of roof tiling works and staircases no. 2

-            Installation of Movement Joints and glass window


 

CO2 Tanks

-          Installation of pipes and electrical wiring, testing and commissioning Combined Shaft and Pump room

-             Finishing, Grating; window; louvre installation Other

-            Watermain works at CLP 132 kV Substation

-             Staircases construction; Steel Bridge assembly and installation at elevated walkway

-             Road Construction, Footpath Construction, Landscape Construction, Irrigation System Construction, Water Pressure Test for Fire Services and Plumbing System in Zone A, B, C

-             Structure Construction, steel fence erection of Wave Deflector Wall at seawall area

-             Slope work

 

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

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

-     Waste generation from the construction activities

 

A7.        The key environmental mitigation measures implemented for the Project 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 regularly inspection to machinery and plants/vehicles on-site to ensure proper functioning;

-     Sorting and storage of general refuse and construction waste;

-     Deployment of silt curtain at the inshore water outflow; 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 project- 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.  Referring to EM&A Manual, the general water quality monitoring should be carried out when there are marine-related construction activities undertaken. General water quality monitoring at the ten monitoring stations (CE, CF, WSR1, WSR2, WSR3, WSR4, WSR16, WSR33, WSR36 and WSR37) was ceased from 1 September 2023 due to the completion of marine-related construction works.

A10. The pre-operation (testing and commissioning) phase of desalination plant started in reporting period. The EM&A works for pre-operation phase water quality were conducted during the reporting period in accordance with the EM&A Manual. Seventy-eight (78) of the


pre-operation phase water quality monitoring results of SS obtained had exceeded the Action Level. Fifty-nine (59) of the pre-operation phase water quality monitoring results of SS obtained during the reporting period had exceeded the Limit Level. After investigation, all exceedances were concluded unrelated to the Project.

A11. Dechlorinated effluent monitoring at two sampling locations (Sampling point T1GKC01AA502/manhole 18) during disinfection was carried out by AJCJV on 2 and 3 December 2023 for Total Residual Chlorine monitoring (TRC). Seven (7) of dechlorinated effluent sample were taken in Sampling point T1GKC01AA502/manhole 18. No TRC exceedance of action or limit levels was obtained during the discharge of dechlorinated effluent. The dechlorinated effluent monitoring is completed.

A12. In this reporting period, 216 times of landfill gas monitoring were recorded at Wan Po Road (Ch0+390 - Ch0+780) and (Ch0+400 - Ch1+200). No action and limit level exceedance for methane, oxygen and carbon dioxide was recorded.

A13. Pre-operation phase monthly coral monitoring was conducted during the reporting period on 28 December 2023, 30 January 2024 and 23 February 2024. No sediment, bleaching or increased mortality in the general condition of all other tagged coral colonies were observed during the monthly 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.

A14.  Pre-operation phase fishery monitoring for dry season was carried out on 17 and 24 February 2024. The result is of the monitoring would be present when it is available.

A15. Weekly site inspections of the construction works were also carried out by ET to audit the mitigation measures implementation status. Thirteen (13) times of weekly Joint site inspections were carried out by ET and IEC.

A16. A summary of the EM&A activities in this reporting period is listed in Table I and summary of the environmental exceedance of the reporting period is tabulated in Table II.

Table I                 Summary Table for EM&A Activities in the Reporting Period

EM&A Activities

Dec 2023

Jan 2024

Feb 2024

Noise Monitoring

N/A

N/A

N/A

Pre-operation Phase

Water Quality Monitoring

12, 14, 16, 19, 21, 23,

26, 28 and 20

December 2023

2, 4, 6, 9, 11, 13, 16,

18, 20, 23, 25, 27 and

30 January 2024

1, 3, 5, 7, 9, 12, 15, 17,

20, 22, 24, 27 and 29

February 2024

TRC Monitoring for Main Disinfection

2 and 3 December

2023

N/A

N/A

Pre-operation Phase Coral Monitoring

28 December 2023

30 January 2024

23 February 2024


 

Pre-operation Phase Fishery Monitoring

N/A

N/A

17 and 24 February

2024

 

Landfill Gas monitoring

1, 2, 4, 5, 6, 7, 8, 9, 10,

11, 12, 13, 14, 15, 16,

18, 19, 20, 21, 22, 23,

27,        28        and        29

December 2023

2, 8, 9, 10, 11 and 12

January 2024

1, 2, 3, 5, 6, 7, 8, 9, 14,

15, 16, 17, 19, 20, 21,

22, 23, 24, 26, 27, 28

and 29 February 2024

Environmental Site Inspection

5, 12, 19, 27 December

2023

2, 9, 16, 25 and 29

January 2024

7, 16, 20 and 28

February 2024

Table II               Summary Table for Exceedance in the Reporting Period

 

Environmental Monitoring

 

 

Parameter

No. of non- Project related

exceedance

Total No. of non-Project related exceedance

No. of Project related

exceedance

Total No. of Project related exceedance

AL

LL

AL

LL

Noise

Leq (30min)

N/A

N/A

N/A

N/A

N/A

N/A

 

 

 

Water

DO

0

0

0

0

0

0

Turbidity

0

0

0

0

0

0

SS

78

59

137

0

0

0

pH

0

0

0

0

0

0

Salinity

0

0

0

0

0

0

TRC

0

0

0

0

0

0

Water (Main Disinfection)

TRC

0

0

0

0

0

0

 

Landfill Gas

O2

0

0

0

0

0

0

CH4

0

0

0

0

0

0

CO2

0

0

0

0

0

0

Complaint Handling and Prosecution

 

A17. One (1) environmental complaint was received during the reporting period. No notifications of summons or prosecution was received during the reporting period.

Reporting Change

 

A18.     There was no change to be reported that may affect the on-going EM&A programme.

 

 

 

 

 

 


 Basic Project Information

 

1.1.     Background

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

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.

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.

1.2.     The Reporting Scope

This is the 16th Quarterly EM&A Report for the Project which summarizes the key findings of the EM&A programme during the reporting period from 1 December 2023 to 29 February 2024.

 

1.3.     Project Organization

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

 


Figure 1.1         Project Organization Chart


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.

Remark

Project Proponent

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

/

 

ANewR Consulting Limited

Independent Environmental Checker (IEC)

 

Alex Chan

 

2618-2831

(Until the end of January 2024)

Lam Environmental Services Limited

Independent Environmental Checker (IEC)

 

Serena Shek

 

6149-6683

(Started from February 2024)

 

1.4.     Summary of Construction Works

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

 

Administration Building

-            Carrying out the floor tiles works at G/F

-            External wall painting works

-            Construction of block work for pipe duct

-            Installation of building services, cable laying, electrical switchboard, testing and commissioning


 

Chemical building

-            Installation of leakage collection pit cover

-            Underground utility construction work

-            Landscape work at roof

-            Defect rectification

Main Electrical & Central Chiller Plant Building

-            Installation of chillers, building services, electrical switchboard and cable laying

-            Installation of Roof Tile for Fuel Tank Room

ActiDAFF

-            Underground utility construction work

-            Installation of access opening cover

-            Construction of staircase no 2

-            Installation of mechanical equipment, piping system, installation of building services, electrical switchboards and cable laying, fiber-reinforced plastic cover Installation

Product Water Storage Tank Building

-            Installation of Cat Ladders in Water Tank A

-            Sealing slab opening in water Tank A

-            Re-construction of Wall PW8 in Water Tank A

-            Installation of metal cladding, building services, cable laying, mechanical equipment, steel pipe

-            Underground utility construction

OSCG Building

-             Protective Coating for dangerous goods Rooms

-             Placing Soil Mix at Roof

-             Installation of Metal Cladding (at East Side) and Roller Shutters and Window

-            Underground utility construction work

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

Reverse Osmosis Building

-           Installation of building services, electrical switchboard, cable laying, Installation of mechanical equipment, steel pipe, Glass Reinforced Plastic pipe, raised floor, testing and commissioning

-           Installation of metal cladding, handrailing, roller shutters, glass canopy and glass house

-           Underground utility construction work

-           Construction of Reinforced Concrete External Wall for Male Toilet


 

Post Treatment Building

-           Installation of building services, Installation of mechanical equipment and piping system, Pressure Test

-           Underground utility construction work

-           Installation of Cat Ladders in Water Tanks

-           Installation of Metal Cladding

-           Placing Soil Mix at Roof

Inspection corridor

-            Installation of building services, Lift installation

-            Construction of roof tiling works and staircases no. 2

-            Installation of Movement Joints and glass window

CO2 Tanks

-          Installation of pipes and electrical wiring, testing and commissioning Combined Shaft and Pump room

-             Finishing, Grating; window; louvre installation Other

-            Watermain works at CLP 132 kV Substation

-             Staircases construction; Steel Bridge assembly and installation at elevated walkway

-             Road Construction, Footpath Construction, Landscape Construction, Irrigation System Construction, Water Pressure Test for Fire Services and Plumbing System in Zone A, B, C

-             Structure Construction, steel fence erection of Wave Deflector Wall at seawall area

-             Slope work

 

 

1.5.     Summary of Environmental Status

A summary of the valid permits, licences, and /or notifications on environmental protection for this Project 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

-

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

30/06/2025

Valid

-

Construction Noise Permit

GW-RE0640-23

22/06/2023

21/12/2023

Valid

-

GW-RE1514-23

22/12/2023

21/06/2024

Valid

-


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 and 6 June 2020

Construction Phase Impact Monitoring

Ceased from 1 September 2023

Pre-operation Phase Impact Monitoring

On-going

TRC Monitoring for 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

Regular            Monitoring            when Construction Works are within the 250m Consultation Zone

In this reporting period, 216 times of landfill gas monitoring were recorded at Wan Po Road (Ch0+390 -  Ch0+780)  and  (Ch0+400  -  Ch1+200).  No

exceedance of action or limit level for methane, oxygen and carbon dioxide was observed

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

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.


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 pre-operation phase of the Project during the reporting period is provided in Appendix C.

 

 

 

 

 

 


 Noise

 

2.1.     Monitoring Requirements

To ensure no adverse noise impact, construction 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.

No impact construction noise monitoring was conducted in the reporting period due to the overly distant monitoring station from the works location, where they were farther than 1 km from the closet monitoring station NSR4 to the works location.

2.2.     Monitoring Parameters, Frequency and Duration

Construction noise level would be 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. 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

 

2.3.     Monitoring Locations

The monitoring locations should normally be 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.

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


The monitoring locations should normally be 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. 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

 

 

2.4.     Action and Limit Levels

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 Construction Noise Monitoring per EM&A Manual

 

Time Period

Action Level

Limit Level (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

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

 

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.


2.5.     Monitoring Results and Observations

 

Referring to EM&A manual Section 4.1.2, the impact noise monitoring should be carried out when there are project-related construction activities undertaken within a radius of 300m from the monitoring stations. As no Contract-related construction activities were undertaken in the reporting period within a radius of 300m from the monitoring stations of the Project 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

 

 

 

 

 

 


 WATER QUALITY

 

In accordance with the recommendations of the EIA, water quality monitoring is required during dredging for the submarine pipelines and, during operation phase. In addition, baseline water quality monitoring was conducted prior to the commencement of marine construction activities. Additional water quality monitoring was conducted during pre-operation.

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

Water quality monitoring for the Project can be divided into the following stages:

-                      Dredging activities during construction phase;

-                      Discharge of effluent from main disinfection during construction phase;

-                      Commissioning activities during pre-operation (testing and commissioning) phase

-                      Operation phase - first year upon operation; and,

-                      Continuous monitoring of effluent quality.

 

3.1.     Water Quality Parameters

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 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

mg/L

TRC

Total Residual Chlorine (Disinfection)

mg/L

TRC

Laboratory measurements

Suspended Solids

mg/L

SS

Iron

mg/L

 

Anti-scalant

mg/L

-

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


In addition to the water quality parameters, other relevant data were 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.

 

3.2.     Monitoring Locations

Pre-operation (testing and commissioning) Phase

The impact water quality monitoring locations are detailed in Table 3.2 and shown in Figure 3.1

below.

Table 3.2           Location of Impact Water Quality Monitoring Station

 

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


 

Figure 3.1          Impact Water Quality Monitoring Locations under EM&A Manual

 

Main Disinfection

According to the approved Flushing and Disinfection Procedure and Supplementary of the Disinfection Procedure for Desalination Plant at Tseung Kwan O, the sampling point of the dechlorinated effluent was located at Contact tank/Product Water Tank (PWT) and T1GKC01AA502/manhole 18.

The approved sampling location was shown in Table 3.3, Figure 3.2 and Figure 3.3 below.

Table 3.3           Sampling location of dechlorinated effluent

System/Loop

Discharge

location

Sampling Location

Parameter

Contact tank/

Product Water Tank (PWT)

 

Culvert

 

Contact tank/PWT

 

 

 

TRC

Connection to dist. network

Manhole 18 in

connection point

Sampling point

T1GKC01AA502/manhole 18


 

 

Figure 3.2         Impact water quality monitoring point for dechlorinated effluent (Contact tank/PWT)


 

Figure 3.3         Impact water quality monitoring point for dechlorinated effluent (Sampling point T1GKC01AA502/manhole 18)


3.3.     Monitoring Equipment, Methodology and QA/QC Procedures

The monitoring methodology, equipment used, and QA/QC procedures could be referred to Section 3.1.2 -3.1.4, 3.1.6-3.1.7 and 3.2 of the Monthly EM&A Report.

3.4.     Action and Limit levels

The Action and Limit Levels have been set based on the derivation criteria specified in the EM&A Manual and based on the baseline water quality monitoring data and the derivation criteria, 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 (Testing and Commissioning) 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 station

Turbidity in NTU (Depth-

averaged)

2.41 NTU or 20% exceedance of value at any  impact  station  compared  with

corresponding data from control station

2.84 NTU or 30% exceedance of value at any  impact  station  compared  with

corresponding data from control station

Salinity  in  PSU

(Depth- averaged)

34.28 PSU or 9% exceedance of value at

any impact station compared with corresponding data from control station

34.60 PSU or 10% exceedance of value

at any impact station compared with corresponding data from control station

Iron      in     mg/L

(Depth- averaged)

0.3 mg/L

0.3 mg/L

Total        residual

chlorine in mg/L

0.01 mg/L

0.01 mg/L

Total        residual

chlorine in mg/L (Disinfection)

0.1 mg/L

0.1 mg/L

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.


3.5.     Monitoring Results and Observations

Construction Phase

Referring to EM&A Manual, the general water quality monitoring should be carried out when there are marine-related construction activities undertaken. General water quality monitoring at the ten monitoring stations (CE, CF, WSR1, WSR2, WSR3, WSR4, WSR16, WSR33, WSR36 and WSR37) was ceased from 1 September 2023 due to the completion of marine-related construction works.

Pre-operation (testing and commissioning) Phase

Considering the first pre-operation phase of Tseung Kwan O Desalination Plant was started in the reporting period, additional marine water quality monitoring was conducted at the thirteen monitoring stations (CE, CF, WSR1, WSR2, WSR3, WSR4, WSR16, WSR33, WSR36, WSR37, NF1,

NF2 and NF3) from 12 December 2023. The Action and Limit Level would be referred to the approved EM&A Manual Table 5.4 First-year Operation Phase Marine Water Monitoring.

The additional marine water quality monitoring was conducted at the thirteen monitoring stations on 12, 14, 16, 19, 21, 23, 26, 28 and 20 December 2023, 2, 4, 6, 9, 11, 13, 16, 18, 20, 23, 25, 27 and 30 January 2024 and 1, 3, 5, 7, 9, 12, 15, 17, 20, 22, 24, 27 and 29 February 2024 during the reporting quarter. The result of the reporting quarterly is presented in Table 3.5.

Seventy-eight (78) of the pre-operation phase water quality monitoring results of SS obtained had exceeded the Action Level. Fifty-nine (59) of the pre-operation phase water quality monitoring results of SS obtained during the reporting period had exceeded the Limit Level.

Investigation on the reason of exceedance has been carried out, where the exceedances of SS were concluded to be unrelated to the Contract as detailed in the Incident Reports on Action Level or Limit Level. Summary of the exceedance is presented in Appendix E.

 


 

Table 3.5           Summary of Impact Water Quality Monitoring Results

 

 

 

 

Location

Parameter

 

 

Salinity (ppt)

Dissolved Oxygen (mg/L)

 

 

pH

 

 

Turbidity (NTU)

 

Suspended Solids (mg/L)

 

 

Temp. (oC)

 

 

TRC (mg/L)

 

 

Iron (mg/L)

 

Surface & Middle

 

Bottom

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

Dec

Jan

Feb

 

CE

Avg.

33.1

32.9

33.5

9.1

9.1

8.5

9.0

9.1

8.5

7.2

7.3

7.6

3.0

2.4

2.4

3.9

4.0

3.3

21.8

23.3

21.9

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

Min.

32.1

32.2

32.6

7.4

8.5

7.7

7.4

8.4

7.7

6.6

7.1

7.2

2.2

1.7

2.0

3.0

2.5

2.5

21.0

21.7

20.1

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

Max..

34.5

33.8

34.2

10.1

9.5

9.3

10.1

9.5

9.4

7.6

7.4

8.0

3.8

3.2

2.7

6.0

7.0

8.0

22.4

24.4

23.1

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

 

CF

Avg.

33.0

32.7

33.2

9.2

9.1

8.5

9.2

9.1

8.6

7.1

7.3

7.6

3.2

2.4

2.6

3.8

3.9

3.2

21.9

23.3

21.9

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

Min.

32.3

31.8

32.7

7.9

8.7

7.8

7.8

8.7

7.8

6.6

7.1

7.1

2.5

1.8

2.1

2.5

2.5

2.5

20.9

21.9

20.1

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

Max..

34.2

33.9

34.0

10.0

9.8

9.2

10.1

9.8

9.1

7.4

7.4

8.0

4.0

3.0

3.1

7.0

7.0

9.0

22.6

24.4

23.4

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

 

WSR1

Avg.

33.2

32.8

33.2

9.0

8.9

8.4

9.1

8.9

8.4

7.2

7.3

7.6

2.2

2.0

1.9

4.0

4.1

3.4

21.9

23.3

21.9

<0.01

<0.01

<0.01

<0.1

<0.1

<0.1

Min.

32.3

31.4

32.4