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 Project.

A2. In accordance with the Environmental Monitoring and Audit (EM&A) Manual for the Project, 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 Project.

A3. This is the 7th Quarterly EM&A Report, prepared by ASCL, for the Project 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 2021 to 30 November 2021.

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:

- Land Survey;

- Construction of ActiDAFF perimeter wall and water tank;

- Construction of Reverse Osmosis (RO) Building - column and wall from Basement to Roof, beams and slabs for Roof Floor; water tank; Electrical Building roof floor slab, columns and wall;

- Construction of Product Water Storage Tank (PWST) perimeter wall and Electrical Building’s 1/F and roof slab;

- Construction of manholes no. 8, no. 9 and no. 10 adjacent to PWST;

- Construction of Post Treatment Building 1/F;

- Construction of ground floor slab and first floor columns and walls of Administration Building;

- Construction of reinforced concrete (R.C) footing of Inspection Corridor;

- Internal finishing work in Main Electrical and Central Chiller Plant Building;

- 610mm diameter socketed H‐piles installation at Outfall Shaft;

- Sinking of 610mm diameter casings at Outfall Shaft;

- Commissioned 610mm pipe piling at Outfall Shaft;

- Outfall Shaft ‐ rockfill removal & dewatering;

- Material lifting and welding work inside its hopper at Outfall Shaft;

- Diver’s work to touch up seabed bottom for concrete plug at Outfall Shaft;

- Excavation & Lateral Support (ELS) erection and marine dredging commencement and disposal at Intake Shaft;

- Sheet piling welding works at Intake Shaft;

- Modification of temporary working platform at Intake Shaft;

- Welding works and installation of waling steelworks inside the cofferdam at Intake Shaft;

- Demobilization of piling rig and 5.5T lifting crane at Intake Shaft;

- Material lifting and struts and railing installation at Intake shaft;

- Preparing H-beams and materials inside the hopper of the derrick barge at Intake Shaft;

- Rock filling in sunk 610mm pipe piles at Intake Shaft;

- Pipe jacking at Combined Shaft for Intake & Outfall pipelines;

- Cable drawpit construction;

- Glass Reinforced Plastic (GRP) pipe lamination and laying;

- Construction of 1^st floor structural wall of Chemical Building;

- Wan Po Road Sewage Works - Temporary Traffic Arrangement (TTA), excavation and laying High-Density Polyethylene (HDPE) pipe;

- Construction of On-Site Chlorine Generation (OSCG) Building footing and roof floor;

- Excavation and lateral support (ELS) at Pump house;

- Dismantling of tower crane TC02

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

- Construction dust and noise generation from marine construction works, excavation works, excavation and lateral support works, breaking of concrete surface and construction works; pipe driving works and sheet piling works

- Waste generation from the construction activities

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

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

- Dust suppression by covering dusty materials with tarpaulin sheet

- Reduction of noise from equipment and machinery on-site

- Sorting and storage of general refuse and construction waste

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

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 project-related exceedance of the Action Level was recorded during the reporting period.

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

A10.General water quality monitoring at the ten monitoring stations (CE, CF, WSR1, WSR2, WSR3, WSR4, WSR16, WSR33, WSR36 and WSR37) were conducted on 2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28 and 30 September 2021; 2, 5, 7, 9*, 12*, 14, 16, 18, 20, 23, 25, 27 and 29 October 2021 and 2, 4, 6, 9, 11, 13, 16, 18, 20, 23, 25, 27 and 30 November 2021.

A11.During the impact monitoring period between September 2021 to November 2021, one hundred and fifty-five (155) of the general water quality monitoring results of suspended solids (SS) obtained had exceeded the Action Level. One hundred and eight (108) of the general water quality monitoring results of SS obtained during the reporting quarter had exceeded the Limit Level.

A12.Investigation on the reason of exceedance has been carried out, where the exceedances of SS on 02/09, 04/09, 07/09, 09/09, 11/09, 14/09, 16/09, 18/09, 21/09 and 25/09; 07/10, 14/10, 16/10, 18/10, 20/10, 23/10, 25/10, 27/10, and 29/10; 02/11, 04/11, 13/11, 16/11, 18/11, 23/11, 25/11, 27/11, and 30/11 were concluded to be unrelated to the project as detailed in the Incident Reports on Action Level or Limit Level Non-compliance along with supporting materials in Appendix L.

A13.Since part of the desalination plant (Wan Po Road and MIC compound/Basketball Court) and the indicative area of natural slope mitigation works fall within the SENT Landfill Extension Consultation Zone in this contract (Figure 5.1), landfill gas monitoring would be required for Wan Po Road and MIC compound/Basketball Court if excavations were conducted at more than 300mm deep. No excavation works were conducted at MIC compound/Basketball Court hence no landfill gas monitoring would be scheduled for MIC compound/Basketball Court at the current stage. 94 times of landfill gas monitoring was recorded during the reporting quarter at Wan Po Road. As confirmed with the Main Contractor, the trench at Wan Po Road was all backfilled and was just waiting for asphalt paving. In any case no trench was deeper than 300mm, thus no LFG monitoring was conducted at Wan Po Road in November 2021.

A14. No exceedance of limit or action level was recorded for the 94 nos. of landfill gas monitoring works between September 2021 and October 2021.

1. BASIC PROJECT INFORMATION

1.1. BACKGROUND

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

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 Project; 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 Project.

1.2. THE REPORTING SCOPE

This is the 7th Quarterly EM&A Report for the Project which summarizes the key findings of the EM&A programme during the reporting period from 1 September 2021 to 30 November 2021.

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.
Project Proponent	SE/CM2	Benny Lam	2634-3573
Supervising Officer (Binnies Hong Kong Limited)	Project Manager	Christina Ko	2608-7302
Supervising Officer (Binnies Hong Kong Limited)	Chief Resident Engineer	Roger Wu	6343-1002
The Jardine Engineering Corporation, Limited, China State Construction Engineering (Hong Kong) Limited and Acciona Agua, S.A. Trading	Project Manager	Stephen Yeung	2807-4665
	Environmental Monitoring Manager	Brian Kam	9456-9541
Acuity Sustainability Consulting Limited	Environmental Team Leader	Jacky Leung	2698-6833
ANewR Consulting Limited	Independent Environmental Checker (IEC)	Louis Kwan	2618-2831

1.4. SUMMARY OF CONSTRUCTION WORKS

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

Key activities carried out in this reporting period for the Project included the following:

- Land Survey;

- Construction of ActiDAFF perimeter wall and water tank;

- Construction of Reverse Osmosis (RO) Building - column and wall from Basement to Roof, beams and slabs for Roof Floor; water tank; Electrical Building roof floor slab, columns and wall;

- Construction of Product Water Storage Tank (PWST) perimeter wall and Electrical Building’s 1/F and roof slab;

- Construction of manholes no. 8, no. 9 and no. 10 adjacent to PWST;

- Construction of Post Treatment Building 1/F;

- Construction of ground floor slab and first floor columns and walls of Administration Building;

- Construction of reinforced concrete (R.C) footing of Inspection Corridor;

- Internal finishing work in Main Electrical and Central Chiller Plant Building;

- 610mm diameter socketed H‐piles installation at Outfall Shaft;

- Sinking of 610mm diameter casings at Outfall Shaft;

- Commissioned 610mm pipe piling at Outfall Shaft;

- Outfall Shaft ‐ rockfill removal & dewatering;

- Material lifting and welding work inside its hopper at Outfall Shaft;

- Diver’s work to touch up seabed bottom for concrete plug at Outfall Shaft;

- Excavation & Lateral Support (ELS) erection and marine dredging commencement and disposal at Intake Shaft;

- Sheet piling welding works at Intake Shaft;

- Modification of temporary working platform at Intake Shaft;

- Welding works and installation of waling steelworks inside the cofferdam at Intake Shaft;

- Demobilization of piling rig and 5.5T lifting crane at Intake Shaft;

- Material lifting and struts and railing installation at Intake shaft;

- Preparing H-beams and materials inside the hopper of the derrick barge at Intake Shaft;

- Rock filling in sunk 610mm pipe piles at Intake Shaft;

- Pipe jacking at Combined Shaft for Intake & Outfall pipelines;

- Cable drawpit construction;

- Glass Reinforced Plastic (GRP) pipe lamination and laying;

- Construction of 1^st floor structural wall of Chemical Building;

- Wan Po Road Sewage Works - Temporary Traffic Arrangement (TTA), excavation and laying High-Density Polyethylene (HDPE) pipe;

- Construction of On-Site Chlorine Generation (OSCG) Building footing and roof floor;

- Excavation and lateral support (ELS) at Pump house;

- Dismantling of tower crane TC02

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/ Licenses/ Notification	Reference	Validity Period	Remarks
Environmental Permit	FEP - 01/503/2015/A	Throughout the Contract
Notification of Construction Works under the Air Pollution Control (Construction Dust) Regulation (Form NA)	Ref. No.: 451539	30/12/2019 - 30/03/2023
Wastewater Discharge Licence (Land and Marine works)	WT00035775-2020	24/07/2020 - 31/07/2025
Chemical Waste Producer Registration	5213-839-A2987-01	Throughout the Contract
Construction Noise Permit (24 hours)	GW-RE0419-21	01/05/2021 - 30/10/2021	CNP for general works, TBM at Combined Shaft and marine works
Construction Noise Permit (24 hours)	GW-RE1041-21	01/11/2021 - 30/04/2022	CNP for general works, TBM at Combined Shaft and marine works
Billing Account for Disposal of Construction Waste	7036276	Throughout the Contract
Dumping at Sea Ordinance (DASO) Permit (Category L)	EP/MD/22‐028	02/08/2021 - 01/02/2022
Dumping at Sea Ordinance (DASO) Permit (Category M)	EP/MD/22-059	20/10/2021 - 19/11/2021
Dumping at Sea Ordinance (DASO) Permit (Category M) - Renewal	EP/MD/22-083	Notification Date: 02 December 2021	Renewal of “Dumping at Sea Ordinance (DASO) Permit to dump materials (Category M) at sea” have been submitted to EPD and the approval was awaited during the reporting period.

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
Impact Monitoring	On-going
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	On-going
Waste Management
Mitigation Measures in Waste Monitoring Plan	On-going
Landfill Gas
Regular Monitoring when Construction Works are within the 250m Consultation Zone	Since part of the desalination plant (Wan Po Road and MIC compound/Basketball Court) and the indicative area of natural slope mitigation works fall within the SENT Landfill Extension Consultation Zone in this contract (Figure 5.1), landfill gas monitoring would be required for Wan Po Road and MIC compound/Basketball Court if excavations were conducted at more than 300mm deep. No excavation works were conducted at MIC compound/Basketball Court hence no landfill gas monitoring would be scheduled for MIC compound/Basketball Court at the current stage. 94 times of landfill gas monitoring was recorded during the reporting quarter at Wan Po Road. As confirmed with the Main Contractor, the trench at Wan Po Road was all backfilled and was just waiting for asphalt paving. In any case no trench was deeper than 300mm, thus no LFG monitoring was conducted at Wan Po Road in November 2021
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 of the Project during the reporting period is provided in Appendix C.

2. NOISE

2.1. MONITORING REQUIREMENTS

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.

In accordance with the EM&A Manual, baseline noise level at the noise monitoring stations were established as presented in the Baseline Monitoring Report. Impact noise monitoring will be conducted once per week in the form of 30-minutes measurements. Leq, L10 and L90 levels recorded at each monitoring station between 0700 and 1900 on normal weekdays.

Referring to EM&A manual Section 4.1.2, the impact noise monitoring should be carried out at all the designated monitoring stations when there are project-related construction activities undertaken within a radius of 300m from the monitoring stations.

No impact monitoring for noise impact 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.

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

2.2. 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.

2.3. 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 Noise 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.

2.4. 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. No monitoring station was located within a radius of 300m of the Project site as shown in Figure 2.4, no impact monitoring for noise impact was conducted in the reporting period.

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

3. WATER QUALITY

In accordance with the recommendations of the EIA, water quality EM&A is required during dredging for the submarine pipelines and, during operation phase. In addition, baseline water quality monitoring will be required prior to the commencement of marine construction activities. 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 will be carried out to allow any deteriorating water quality to be readily detected and timely action taken to rectify the situation. The status and locations of water quality sensitive receivers and the marine works location may change after issuing this Document. If required, the ET in consultation with IEC will propose monitoring locations and seek approval from EPD.

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;

- Operation phase - first year upon commissioning; and,

- Continuous monitoring of effluent quality.

In addition, the marine works contractor is required to complete a silt curtain efficiency test for the combined use of floating silt curtain type and cage type silt curtain for dredging at seawater intake to confirm the silt curtain reduction efficiency assumptions of the assessment. The details of testing plan together with the silt curtain deployment plan shall be submitted by the ET to seek approval from the IEC and EPD.

With the onset of marine dredging activities in late April at Outfall Shaft Area, a silt curtain efficiency test has been conducted at the Outfall Shaft Area on 16t April 2021 at 6 monitoring intervals (08:00, 10:00, 12:00, 14:00, 16:00, 18:00). The baseline monitoring event has been conducted on 10 April 2021 at 5 monitoring locations. Testing protocols and methodologies had followed the guidelines as presented in the EM&A Manual Annex C. Detailed analysis of in-situ and laboratory data was presented in a separate report which has been submitted to EPD after approval by IEC on 31 May 2021. The overall Silt Removal Effectiveness at Outfall Shaft Area for the combined used of cage and floating type silt curtains was 95.28%.

3.1. IMPACT MONITORING METHODOLOGY

3.1.1. 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 to be measured in the baseline monitoring are listed in Table 3.1.

Table 3.1 Parameters measured in the baseline 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 NOTE2	mg/L	Fe
Anti-scalant as Reactive Phosphorus NOTE2	mg/L	PO4 as P-

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

NOTE 2: The testing methods shall be submitted to EPD for approval prior to the commencement of monitoring programme

In addition to the water quality parameters, other relevant data will also be 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.

3.1.2. MONITORING LOCATIONS

The water quality monitoring locations for baseline in accordance to the EM&A Manual and Contract Specification are shown in Figure 3.1 respectively, and detailed in Table 3.2 below. A schedule for water quality monitoring shall be prepared by the ET and approved by IEC and EPD prior to the commencement of the monitoring.

Table 3.2 Location of Baseline 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

WSR1 to WSR37 were identified in accordance with Annex 14 of the EIAO-TM as well as Clause

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

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

3.2. MONITORING EQUIPMENT

For water quality monitoring, the following equipment will be used:

Dissolved Oxygen and Temperature Measuring Equipment - The instrument will be a portable, weatherproof dissolved oxygen measuring instrument complete with cable, sensor, comprehensive operation manuals, and will be operable from a DC power source. It will be 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 shall have 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 shall be 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 will be a portable, weatherproof turbidity- measuring unit complete with cable, sensor and comprehensive operation manuals. The equipment will be operated from a DC power source, it will have a photoelectric sensor capable of measuring turbidity between 0 - 1000 NTU and will be 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 will be 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) will be 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 should be suitably calibrated. The ET shall seek approval for their proposed equipment with the client prior to deployment.

Current Velocity and Direction - No specific equipment is recommended for measuring the current velocity and direction. The environmental contractor shall seek approval of their proposed equipment with the client prior to deployment.

Positioning Device - A Global Positioning System (GPS) shall be used during monitoring to allow accurate recording of the position of the monitoring vessel before taking measurements. The Differential GPS, or equivalent instrument, should be 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, will be used (e.g. Kahlsico Water Sampler 13SWB203 or an approved similar instrument). The water sampler will have a positive latching system to keep it open and prevent premature closure until released by a messenger when the sampler is at the selected water depth.

Total Residual Chlorine for Discharge of Sterilization Water - Total residual chlorine (TRC) shall be measured in-situ using a handheld colorimeter with its testing toolkits.

3.3 SAMPLING / TESTING PROTOCOLS

All in situ monitoring instruments will be 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 will be checked with certified standard solutions before each use.

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

3.4 LABORATORY MEASUREMENT AND ANALYSIS

All laboratory work shall be carried out in a HOKLAS accredited laboratory. Sufficient volume of each water sample shall be collected at the monitoring stations for carrying out the laboratory analyses. Using chain of custody forms, collected water samples will be transferred to an HOKLAS accredited laboratory for immediate processing. The determination work shall start within the next working day after collection of the water samples. The laboratory measurements shall be provided to the client within 5 working days of the sampling event. Analytical methodology and sample preservation of other parameters will be 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 submitted information should include pre-treatment procedures, instrument use, Quality Assurance/Quality Control (QA/QC) details (such as blank, spike recovery, number of duplicate samples per-batch etc), detection limits and accuracy. The QA/QC details shall be in accordance with requirements of HOKLAS or another internationally accredited scheme.

Parameters for laboratory measurements, their standard methods and their 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 (mg/L)	Instrumental, CTD	0.1	-	+-25%
Temperature (oC)	Instrumental, CTD	0.1	-	+-25%
pH	Instrumental, CTD	0.1	-	+-25%
Turbidity (NTU)	Instrumental, CTD	0.1	-	+-25%
Salinity (0/00)	Instrumental, CTD	0.1	-	+-25%
Suspended Solids (mg/L)	APHA 17th Ed 2540D	1.0	2.0	+-17%
Total Residual Chlorine (mg/L)	APHA 21st Ed 4500 - Cl G NOTE1	0.1NOTE1	0.2NOTE1	+-10% NOTE1
Iron-soluble	USEPA 6010C NOTE 1	0.2NOTE1	0.2NOTE1	+-25%NOTE1
Anti-scalant as Reactive phosphorus	APHA 4500P: B&F NOTE1	0.01NOTE1	0.01NOTE1	+-25%NOTE1

NOTE1: The testing methods, Quality Assurance/Quality Control (QA/QC) details, detection limits and accuracy shall be submitted to EPD for approval prior to the commencement of monitoring programme.

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

3.5. MONITORING PROGRAMME

The ET of the Project had conducted the baseline water monitoring between 12 May 2020 to 6 June 2020 at the thirteen designated monitoring stations and the six designated monitoring at waters near TKO in accordance with the EM&A Manual and Contract Specification respectively. The monitoring results were presented in the Baseline Water Quality Monitoring Report separately.

Marine construction for the Project has been conducted in the reporting period from September 2021 to November 2021.

3.5.1. SAMPLING FREQUENCY

During periods when there are dredging works, impact monitoring should be undertaken at the monitoring stations as shown in Figure 3.1 and Table 3.2 three days per week during the construction phase after the commencement of marine construction works and dredging activities. Monitoring at each station would be undertaken at both mid-ebb and mid-flood tides on the same day. The tidal range selected for the impact monitoring will be at least 0.5 m for both flood and ebb tides as far as practicable. The interval between two sets of monitoring would not be less than 36 hours. The monitoring frequency would be increased in the case of exceedances of Action/Limit Levels if considered necessary by ET. Monitoring frequency would be maintained as far as practicable.

The monitoring location/position, time, water depth, water temperature, salinity, weather conditions, sea conditions, tidal stage, special phenomena and work underway at the marine works site will be recorded.

3.5.2. SAMPLING DEPTHS & REPLICATION

For impact monitoring, each station will be sampled and measurements/ water samples will be taken at three depths, 1 m below the sea surface, mid-depth and 1 m above the seabed. For stations that are less than 3 m in depth, only the mid depth sample shall be taken. For stations that are less than 6 m in depth, only the surface and seabed sample shall be taken. For in situ measurements, duplicate readings shall be made at each water depth at each station. Duplicate water samples shall be collected at each water depth at each station. A summary of the results was recorded in the data record sheet in Appendix I.

3.5.3. ACTION AND LIMIT LEVELS

The Action and Limit Levels have been set based on the derivation criteria specified in the EM&A Manual, as shown in Table 3.4 below. Based on the baseline water quality monitoring data and the derivation criteria specified in Table 3.4, the Action/Limit Levels have been derived and are presented in Table 3.5.

Table 3.4 Criteria of Action and Limit Levels for Water Quality

Parameters	Action	Limit
Construction Phase Impact Monitoring
DO in mg/L	Surface and Middle 5%-ile of baseline data for surface and middle layer Bottom 5%-ile of baseline data for bottom layers 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)	≥ 95 %-ile of baseline data or 20% exceedance of value at any impact station compared with corresponding data from control station	≥ 99 %-ile of baseline data or 30% exceedance of value at any impact station compared with corresponding data from control station
Turbidity in NTU (Depth-averaged)	≥ 95 %-ile of baseline data or 20% exceedance of value at any impact station compared with corresponding data from control station	≥ 99 %-ile of baseline data or 30% exceedance of value at any impact station compared with corresponding data from control station
First-year Operation Phase Monitoring
DO in mg/L	Surface and Middle 5%-ile of baseline data for surface and middle layer Bottom 5%-ile of baseline data for bottom layers 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)	≥ 95 %-ile of baseline data or 20% exceedance of value at any impact station compared with corresponding data from control station	≥ 99 %-ile of baseline data or 30% exceedance of value at any impact station compared with corresponding data from control station
Turbidity in NTU (Depth-averaged)	≥ 95 %-ile of baseline data or 20% exceedance of value at any impact station compared with corresponding data from control station	≥ 99 %-ile of baseline data or 30% exceedance of value at any impact station compared with corresponding data from control station
Salinity in PSU (Depth-averaged)	109% of baseline level or 9% exceedance of value at any impact station compared with corresponding data from control station	110% of baseline level or 10% exceedance of value at any impact station compared with corresponding data from control station
Iron in mg/L (Depth-averaged)	0.3 mgL-1	0.3 mgL-1

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


Figure 2.3 NSR31 School of Continuing and Professional Studies - CUHK

CONTENTS