Revision History

Rev.

Description of Modification

Date

 

1.

 

First Issue for Comments

 

11/10/2023

 

2

 

Revised according to the comment

 

17/10/2023

 

3

 

Revised according to the comment

 

17/10/2023

 

 

 

 

 


CONTENTS

Executive Summary............................................................................................................................................................ 4

1.          Basic Contract Information............................................................................................................................ 10

2.          Noise........................................................................................................................................................................ 15

3.          Water Quality....................................................................................................................................................... 19

4.          Waste....................................................................................................................................................................... 25

5.          Landfill Gas Monitoring................................................................................................................................... 26

6.          Ecology.................................................................................................................................................................... 30

7.          Summary of Exceedance, Complaints, Notification of Summons and Prosecutions.............. 31

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

9.          Future Key Issues............................................................................................................................................... 34

10.      Conclusions and Recommendations.......................................................................................................... 36

 

 

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                           Landfill Gas Equipment Calibration Certificate

Appendix G                          Landfill Gas Monitoring Data

Appendix H                          Waste Flow Table

 

Appendix I                            Site Inspection Proforma

 

Appendix J                            Complaint Log

 

 

 

 

 

 

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 43rd 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 September to 30 September 2023.

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

-            Carrying out the floor tiles works at 1/F

-            Installation of building services, cable laying, electrical switchboard, doors and handrails

-            Construction of 3 dog houses on roof

-            Construction of block wall in the pipe duct

 

Chemical building

-            Construction of concrete slab for safety shower

-            Installation of leakage collection pit cover

-            Underground utility construction work

 

Main Electrical & Central Chiller Plant Building

-            Installation of roof tile for fuel tank room, chillers, building services, electrical switchboard and cable laying

 

ActiDAFF

-            Underground utility construction work

-            Installation of access covers on roof

-            Construction of staircase no 2

-            Installation of mechanical equipment, piping system, building services, electrical switchboards and cable laying

 

Product Water Storage Tank Building

-            Installation of Cat Ladders in Water Tank A

-            Sealing Slab Openings in Water Tank A

-            Re-construction of Wall PW8 in Water Tank A

-            Underground utility construction

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

 

OSCG Building

-            Installation of Design for Manufacturing and Assembly (DfMA) Panel, metal cladding and roller shutters and window

-            Underground utility construction work

-           Installation of building services, mechanical equipment, metal cladding and roller shutters and window

 

Reverse Osmosis Building

-          Installation of building services, electrical switchboard, mechanical equipment, steel pipe, Glass Reinforced Plastics (GRP) pipe, pressure test of the GRP pipe, Membrane Loading, raised floor

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

-            Underground utility construction work

-            Pipe laying at corridor and Backfilling Work

 

Post Treatment Building

-           Installation of louvres, cat ladders, handrailing and metal cladding

-           Installation of building services, mechanical equipment and GRP pipe

-            Underground utility construction work

 

Inspection corridor

-            Construction of roof waterproofing works

-            Construction of staircase no. 1 and 2

-            Installation of building services

 

CO2 Tanks

-            Installation of pipes and electrical wiring Combined Shaft and Pump room

-            Internal finishing, door, window and louver Other

-            Watermain works at CLP 132 kV Substation

-            Structure Construction and steel fence election of Wave Deflector Wall at seawall area

-            Staircases construction at elevated walkway

-            Steel Bridge assembly and installation

-            Rock anchor installation of slope work

-            Marine works completed

 

 

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

 

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 marine areas; and

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

 

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

A10. In this reporting period, 72 times of landfill gas monitoring were conducted at TKO Area 137 (Ch1+340 - Ch1+600). No action or limit level exceedance was recorded during the reporting period.

A11. Joint site inspections of the construction work by ET and IEC were carried out on 5, 12, 19 and 26 September 2023 to audit the mitigation measures implementation status. Observation and 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

 

A12. No environmental complaint, notification of summons and prosecution was received in the reporting period.


 

Reporting Change

 

A13. 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

 

A14. Key activities anticipated in the next reporting period for the Contract will include the followings:

 

 

Administration Building

-            Carrying out the floor tiles works at G/F

-            Construction of 4 dog houses on the roof.

-            Construction of block wall in the pipe duct

-            Installation of building services, cable laying, electrical switchboard

 

Chemical building

-            Installation of leakage collection pit cover

-            Construction of concrete slab for safety showers

-            Construction of trunk load pits

-            Underground utility construction work

-            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 covers on roof

-            Construction of staircase no 2

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

 

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

-             Installation of Design for Manufacturing and Assembly (DfMA) Panel and metal cladding

-             Installation of Roller Shutters and Window

-             Coating and Installation of Grating Cover for Brine Tank

-            Underground utility construction work

-            Installation of building services, mechanical equipment and cable laying

 

Reverse Osmosis Building

-           Installation of building services, electrical switchboard, mechanical equipment, steel pipe, Glass Reinforced Plastics (GRP) pipe, pressure test of the GRP pipe, Membrane Loading, raised floor

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

glass house

-            Underground utility construction work

-            Pipe laying at corridor outside Toilet and Backfilling Work

 

Post Treatment Building

-           Installation of service staircase tower, louvres, cat ladders, handrailing and metal cladding

-           Installation of building services, Installation of mechanical equipment and

piping system

-           Underground utility construction work

 

Inspection corridor

-            Construction of roof waterproofing works

-            Construction of staircases no. 1 and 2

-            Installation of Movement Joints

-            Construction of Screeding works on the deck level

-            Installation of building services

 

CO2 Tanks

-          Installation of pipes and electrical wiring Combined Shaft and Pump room

-            Internal finishing, Door; window; Lover Installation

Other

-             Rock anchor installation

-            Watermain works at CLP 132 kV Substation

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

-             Staircases construction; Steel Bridge assembly and installation at elevated

walkway

-             Foot plinth concreting and barrier erection at flexible barrier

-             Final check of Marine Diffuser Pipe

 

 

A15. 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


A16. 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 silt curtain at the marine areas.

 

 

 

 

 


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 43rd Monthly EM&A Report for the Contract which summarizes the key findings of the EM&A programme during the reporting period from 1 September to 30 September 2023.

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

Acuity Sustainability Consulting Limited

Environmental Team Leader

 

Jacky Leung

 

2698-6833

 

ANewR Consulting Limited

Independent Environmental Checker (IEC)

 

Mr. CHAN Yi

Chun, Alex

 

2618-2831

 

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

-            Carrying out the floor tiles works at 1/F

-            Installation of building services, cable laying, electrical switchboard, doors and handrails

-            Construction of 3 dog houses on roof

-            Construction of block wall in the pipe duct

 

Chemical building

-            Construction of concrete slab for safety shower

-            Installation of leakage collection pit cover

-            Underground utility construction work

 

Main Electrical & Central Chiller Plant Building

-            Installation of roof tile for fuel tank room, chillers, building services, electrical switchboard and cable laying

 

ActiDAFF

-            Underground utility construction work

-            Installation of access covers on roof

-            Construction of staircase no 2

-            Installation of mechanical equipment, piping system, building services, electrical switchboards and cable laying

 

 

Product Water Storage Tank Building

-            Installation of Cat Ladders in Water Tank A

-            Sealing Slab Openings in Water Tank A

-            Re-construction of Wall PW8 in Water Tank A

-            Underground utility construction

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

 

OSCG Building

-            Installation of Design for Manufacturing and Assembly (DfMA) Panel, metal cladding and roller shutters and window

-            Underground utility construction work

-           Installation of building services, mechanical equipment, metal cladding and roller shutters and window

 

Reverse Osmosis Building

-          Installation of building services, electrical switchboard, mechanical equipment, steel pipe, Glass Reinforced Plastics (GRP) pipe, pressure test of the GRP pipe, Membrane Loading, raised floor

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

-            Underground utility construction work

-            Pipe laying at corridor and Backfilling Work

 

Post Treatment Building

-           Installation of louvres, cat ladders, handrailing and metal cladding

-           Installation of building services, mechanical equipment and GRP pipe

-            Underground utility construction work

 

Inspection corridor

-            Construction of roof waterproofing works

-            Construction of staircase no. 1 and 2

-            Installation of building services

 

CO2 Tanks

-            Installation of pipes and electrical wiring

Combined Shaft and Pump room

-            Internal finishing, door, window and louver

Other

-            Watermain works at CLP 132 kV Substation

-            Structure Construction and steel fence election of Wave Deflector Wall at seawall area

-            Staircases construction at elevated walkway

-            Steel Bridge assembly and installation

-            Rock anchor installation of slope work

-            Marine works completed

 

 


 

 

 

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

-

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

Construction Noise Permit

GW-RE0640-23

22/06/2023

21/12/2023

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.

Impact Monitoring

Ceased from 1 September

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 250 m Consultation Zone

 

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 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

 

Day time:

Continuously in

 

Daytime:

0700-1900

Leq               5min/Leq               30min

Leq 30min

0700-1900

(during normal weekdays)

(average            of            6

consecutive Leq 5min)

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.

 


 


文字方塊: 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 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;

 

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.


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 3.3.

 

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

3.11.    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