Revision History
Rev. |
Description of Modification |
Date |
1. |
First Issue
for Comments |
10/11/2023 |
2. |
Revised according to the comment |
20/11/2023 |
CONTENTS
7. Summary of Exceedance, Complaints, Notification of Summons and Prosecutions.............. 31
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 44th 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 October to 31 October 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 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 -
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 |
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 3, 10, 17, 27 and 31 October 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 -
External wall painting works -
Construction of block work for pipe duct -
Installation of building services, cable laying, electrical switchboard, T&C |
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, FRP 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 DG Rooms -
Placing Soil
Mix at Roof -
Installation of Metal Cladding (at East Side) -
Installation of Roller Shutters and Window -
Underground utility construction work -
Installation of building services, mechanical equipment and cable laying, T&C |
Reverse Osmosis Building -
Installation of building services, electrical switchboard, cable
laying, Installation of mechanical equipment, steel pipe,
GRP pipe, raised
floor, T&C -
Installation
of metal cladding, handrailing, roller shutters, glass canopy and glass house -
Underground utility construction work -
Construction of RC 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 -
Construction of staircases no. 2 -
Installation of Movement Joints -
Installation of glass window |
|
CO2
Tanks -
Installation
of pipes and electrical wiring, T&C Combined
Shaft and Pump room -
Finishing,
Grating; window; Lover Installation Other -
Shotcreteing, Rock anchor installation -
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 FS and PL system in -
Zone
A, B, C -
Structure
Construction, steel fence erection of Wave Deflector Wall at seawall area |
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.
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 44th Monthly EM&A Report for the Contract which summarizes the key findings of the EM&A programme during the reporting period from 1 October to 31 October 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 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 -
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 |
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 2023 |
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.
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.
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
3.1. 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.