Aurecon Hong Kong Limited (Aurecon) was appointed to undertake the role of Environmental Team (ET) and carry out Environmental Monitoring and Audit for the North East New Territories (NENT) Landfill Extension.

An Environmental Permit (EP) No. EP-292/2007 was issued by the Environmental Protection Department (EPD) on 26 November 2007 for the construction of this project based on the Environmental Impact Assessment (EIA) Report (Register No: AEIAR-111/2007) approved by the EPD. The latest EP No. FEP-01/292/2007 was subsequently issued by the EPD in April 2022.

In accordance with the requirements specified in Section 2.5, Section 2.10 and Section 12.2 of the approved Environmental Monitoring and Audit (EM&A) and Environmental Permit (EP and FEP) condition 3.2, baseline monitoring report should be submitted to the Director of Environmental Protection (DEP) for approval before commencement of construction.

The baseline monitoring covered Air Quality, Noise and Surface Water Quality. This Baseline Monitoring Report presents the monitoring works between 10 June 2022 and 18 July 2022, and between 29 October 2022 and 11 November 2022. It aims to establish the baseline levels in accordance with the EM&A Manual.

Data collected from baseline air quality, noise and water quality monitoring were reviewed and analyzed to determine the action and limit levels of air quality, noise and water quality impact monitoring during the construction stage of the project. Details of the methodology, locations and results are presented in the report.

1. Introduction

1.1. Background

1.1.1. The Environmental Protection Department (EPD) commissioned a study in Year 2000 on the Extension of Existing Landfills and Identification of Potential New Waste Disposal Sites. Amongst the potential sites recommended in this territory-wide study is the extension of the existing North-East New Territories (NENT) Landfill, with a target capacity of about 19 Mm³. The proposed extension of about 70 ha, is located immediately east of the existing NENT Landfill. A large proportion of the Extension area is in fact the Stockpile and Borrow Area of the existing landfill.

1.1.2. The North-East New Territories Landfill Extension (the NENTX Project) is a designated project. The Environmental Impact Assessment (EIA) Report (AEIAR-111/2007) and an Environmental Monitoring and Audit Manual were approved on 20 September 2007. The project is governed by an Environmental Permit (EP) (EP-292/2007) which was granted on 26 November 2007. A further of EP (FEP) was applied and the FEP (FEP-01/292/2007) was subsequently granted in April 2022.

1.1.3. In accordance with the requirements specified in Section 2.5, Section 2.10 and Section 12.2 of the approved Environmental Monitoring and Audit (EM&A) and Environmental Permit (EP and FEP) condition 3.2, baseline monitoring report should be submitted to the Director of Environmental Protection (DEP) for approval before commencement of construction.

1.1.4. Aurecon Hong Kong Limited (Aurecon) was appointed to undertake the role of Environmental Team (ET) for the baseline monitoring programme. The baseline monitoring covered Air Quality, Noise and Surface Water Quality.

1.2. Purpose of this Report

1.2.1. The purpose of this report is to set the baseline levels for air quality, noise and surface water. These baseline levels will be used as the basis for compliance check during the impact monitoring in construction stage of the Project. It also collects information and observations on the site characteristics prior to the commencement of construction in order to make comparisons between pre-development and post-development.

1.2.2. This baseline monitoring report presents the findings of the baseline monitoring programme conducted between 10 June 2022 and 18 July 2022, and between 29 October 2022 and 11 November 2022. It presents the monitoring locations, equipment, period, methodology, results and observations for Air Quality, Noise and Surface Water Quality during the baseline period.

1.3. Structure of the Report

1.3.1. The structure of the report is as follows:

Section 1 – Introduction

Section 2 – Dust Monitoring

Section 3 – Noise Monitoring

Section 4 – Surface Water Monitoring

Section 5 – Conclusion

2. Dust Monitoring

2.1 Monitoring Requirement

2.1.1 According to the EM&A Manual, baseline dust monitoring was conducted for 14 consecutive days prior commissioning of the construction. 1-hr TSP baseline monitoring was conducted between 26 June 2022 and 13 July 2022 at AM1 and AM3, and between 4 July 2022 and 17 July 2022 at AM2, inclusive of both days. 24-hr TSP baseline monitoring was conducted between 26 June 2022 and 13 July 2022 at AM1 and AM3, and between 4 July 2022 and 18 July 2022 at AM2, inclusive of both days.

2.2 Monitoring Parameters, Frequency and Location

2.2.1 According to the EM&A Manual, three monitoring stations namely AM(D)1, AM(D)2 and AM(D)3 are selected for the baseline monitoring.

2.2.2 A baseline monitoring plan has been submitted to IEC and EPD including the proposal of change of monitoring locations. Due to limited access to the original monitoring locations at AM(D)1, AM(D)2 and AM(D)3, the adjusted stations at AM1, AM2 and AM3 were agreed with IEC prior to the baseline monitoring. The locations of adjusted dust monitoring locations are shown in Figure 2.

2.2.3 Adverse weather was recorded between 30 June 2022 and 3 July 2022 and typhoon signal no. 8 was hoisted from 1 July 2022 to 2 July 2022. The dust monitoring was suspended between 30 June 2022 and 3 July 2022 at AM1 and AM3 due to safety concern. As such, additional monitoring dates were conducted from 10 July 2022 to 13 July 2022 for AM1 and AM3.

2.2.4 Due to electricity and technical issues, the High Volume Sampler would need to be checked before operation. 24-hr TSP monitoring at AM2 on 15 July 2022 was suspended and it was resumed on 16 July 2022.

2.2.5 The detailed monitoring schedule is shown in Appendix A. The frequency and duration are shown in Table 2-2.

Table 2-1 Locations of Dust Monitoring Stations

Monitoring Station	Representative for	Monitoring Parameters
AM1	Tung Lo Hang	1-hr and 24-hrTSP
AM2	Heung Yuen Wai	1-hr and 24-hrTSP
AM3	Wo Keng Shan Tsuen	1-hr and 24-hrTSP

Table 2-2 Dust Baseline Monitoring Parameters, Frequency and Duration

Monitoring Station	Parameter	Frequency and Duration
AM1, AM2, AM3	1-hr TSP	At least 3 times per day for 14 consecutive days
AM1, AM2, AM3	24-hr TSP	Daily sample for 14 consecutive days

2.3 Monitoring Equipment

2.3.1 High volume samplers (HVSs) were used for carrying out 24-hr TSP monitoring. For 1-hr TSP monitoring, direct reading dust meters were used to measure 1-hr TSP levels.

2.3.2 Table 2-3 summarises the equipment that were used in the baseline dust monitoring programme. The calibration certificates are shown in Appendix B.

Table 2-3 Dust Monitoring Equipment

Equipment	Model	Monitoring Station
High Volume Sampler (HVS)	TE-5170X (S/N: 1856)	AM1
	TE-5170X (S/N: 2894)	AM2
	TE-5170X (S/N: 1855)	AM3
Direct Reading Dust Meter	Sibata LD-5R (S/N: 0Z4544)	AM1
	Sibata LD-5R (S/N: 0Z4545)	AM2
	Sibata LD-5R (S/N: 882150)	AM3
Calibration Kit (for HVS)	Tisch TE-5028A (S/N: 3702)	AM1
	Tisch TE-5025A (S/N: 1612)	AM2
	Tisch TE-5028A (S/N: 3702)	AM3

2.4 Monitoring Methodology

2.4.1 The 1-hr TSP impact monitoring was conducted using a portable direct reading dust meter.

2.4.2 The measuring procedures of the 1-hr dust meter has been undertaken in accordance with the Manufacturer’s Instruction Manual as follows:

• Place the 1-hr dust meter at least 1.3m above ground;

• Set POWER to “ON” and make sure that the battery level will not be flashed or in low level;

• Pull the air sampling inlet cover up;

• Push the knob at MEASURE position;

• Set time/mode setting to [BG] by pushing the time setting switch. Then, start the background measurement by pushing the start/stop switch once. It will take 6 sec. to complete the background measurement;

• turn knob to SENSI. ADJ position and press in;

• Push Start/Stop switch once;

• Gently return knob to the MEASURE position;

• Push the time setting switch to change the time setting display to [LOG] at the bottom left of the liquid crystal display;

• Remove the cap and start measurement; and

• Information such as sampling date, time, count value and site condition will be recorded during the monitoring period.

2.4.3 The 24-hr TSP baseline monitoring has been conducted using a High Volume Sampler (HVS).

2.4.4 The HVS has been set-up at the monitoring location with a fixed power supply for operation. The measuring procedures of the 24-hr TSP measurements has been undertaken in accordance with the specifications listed in the EM&A Manual. Each HVS includes a motor, a filter holder, a flow controller and a sampling inlet in accordance with the performance specification of the USEPA Standard Title 40, Code of Federation Regulations Chapter 1 (Part 50), Appendix B. The measuring procedures of the 24-hr dust meter was undertaken in accordance with the Manufacturer’s Instruction Manual as follows:

• The power supply will be checked to ensure the HVS works properly;

• The filter holder and the area surrounding the filter will be cleaned;

• The filter holder will be removed by loosening the four bolts and a new filter on a supporting screen will be aligned carefully;

• The filter will be properly aligned on the screen so that the gasket formed an airtight seal on the outer edges of the filter;

• The swing bolts will be fastened to hold the filter holder down to the frame. The pressure applied should be sufficient to avoid air leakage at the edges;

• The shelter lid will be closed and secured with the aluminium strip;

• The HVS will be warmed-up to establish run-temperature conditions;

• A new flowrate record sheet will be set into the flow recorder;

• The programmable timer will be set for a sampling period of 24 hour, and the starting time, weather condition and the filter number will be recorded;

• The initial elapsed time will be recorded;

• At the end of sampling, the sampled filter will be removed carefully and folded in half-length so that only surfaces with collected particulate matter will be in contact;

• The sample will be placed in a clean plastic envelope and sealed;

• All monitoring information will be recorded on a standard data sheet; and

• The filters will be taken back to HOKLAS accredited laboratory for analysis.

2.4.5 In addition, site conditions and dust sources were recorded in a standard form for direct input into a database.

2.5 Monitoring Results

2.5.1 The baseline dust monitoring results are summarized in Table 2-4 and the monitoring data together with graphical presentations are presented in Appendix C and Appendix D.

Table 2-4 Summary of Baseline 1-hr TSP Monitoring Results

Dust Monitoring Station	Average 1-hr TSP Concentration, µg/m³ (Range)	Average 24-hr TSP Concentration, µg/m³ (Range)
AM1	54 (32 – 84)	53 (24 – 109)
AM2	45 (23 – 61)	33 (13 – 57)
AM3	54 (37 – 74)	51 (27 – 81)

2.6 Wind Data Monitoring

2.6.1 During the baseline monitoring period. wind data from existing weather station in the vicinity of the designated monitoring location, i.e. Ta Kwu Ling station operated by Hong Kong Observatory was adopted. It is considered that the wind data obtained from Ta Kwu Ling station are representative of the Project area and could be used for the baseline dust monitoring programme for the Project. The results for wind data monitoring are presented in Appendix F.

2.6.1

2.7 Action and Limit Level for Air Quality (Dust)

2.7.1 The action and limit levels for construction dust are defined in Table 2-5.

Table 2-5 Criteria of Action and Limit Levels for Air Quality (Dust)

Parameters

Action Level

Limit (ug/m³)

24-hr TSP

For baseline level ≤ 200 mg/m³, Action level = (130% of baseline level + Limit level)/2

For baseline level > 200 mg/m³, Action level = Limit level

260

1-hr TSP

For baseline level ≤ 384 mg/m³, Action level = (130% of baseline level + Limit level)/2

For baseline level > 384 mg/m³, Action level = Limit level

500

2.7.2 Following the above criteria, the Action and Limit Levels for air quality impact monitoring is presented in Table 2-6 and Table 2-7.

Table 2-6 Action and Limit Levels for 1-hr TSP

Location	Action Level, µg/m³	Limit Level, µg/m³
AM1	285	500
AM2	279	500
AM3	285	500

Table 2-7 Action and Limit Levels for 24-hr TSP

Location	Action Level, µg/m³	Limit Level, µg/m³
AM1	164	260
AM2	152	260
AM3	163	260

2.8 Event and Action Plan

2.8.1 The action and limit levels for air quality monitoring are defined in Table 2-6 and 2-7. Should non-compliance of the criteria occurs, action in accordance with the action plan in Table 2-8 shall be carried out.

Table 2-8 Event and Action Plan for dust monitoring

Event	ET	IEC	Contractor
Exceedance of Action Level
1.Exceedance for one sample	• Identify source • Prepare Notification of Exceedance • Inform IEC and Contractor • Repeat measurement to confirm findings • Increase monitoring frequency to daily if exceedance is due to the Project and continue until the monitoring results reduce to below action level	• Verify the Notification of Exceedance • Check monitoring data submitted by ET and Contractor's working methods • Discuss with ET and Contractor on proposed remedial measures	• Rectify any unacceptable practice • Amend working methods if appropriate
2.Exceedance for two or more consecutive samples	• Identify source • Prepare Notification of Exceedance • Inform Contractor and IEC • Repeat measurements to confirm findings • Increase monitoring frequency to daily if exceedance is due to the Project and continue until the monitoring results reduce to below action level • Discuss with IEC for remedial action required • Ensure remedial measures are properly implemented • Continue monitoring at daily intervals if exceedance is due to the Project • If no exceedance for 3 consecutive days, cease additional monitoring	• Verify the Notification of Exceedance • Check monitoring data submitted by ET and Contractor's working methods • Discuss with ET and Contractor on proposed remedial measures • Review with analysed results submitted by ET • Review the proposed remedial measures by Contractor • Supervise the implementation of remedial measures	• Submit proposals for remedial actions to IEC within 3 working days of notification • Implement the agreed proposals • Amend proposal if appropriate

~~Table 2-8 Event and Action Plan for dust monitoring~~

Event	ET	IEC	Contractor
Exceedance of Limit Level
1.Exceedance for one sample	• Identify source • Prepare Notification of Exceedance • Inform IEC and Contractor • Repeat measurement to confirm findings • Increase monitoring frequency to daily if exceedance is due to the Project and continue until the monitoring results reduce to below limit level • Assess effectiveness of Contractor's remedial actions and keep EPD and IEC informed of the results	• Verify the Notification of Exceedance • Check monitoring data submitted by ET and Contractor's working methods • Discuss with ET and Contractor potential remedial actions • Supervise the implementation of remedial measures	• Take immediate action to avoid further exceedance • Submit proposals for remedial actions to IEC within 3 working days of notification • Implement the agreed proposals • Amend proposal if appropriate
2.Exceedance for two or more consecutive samples	• Identify source • Prepare Notification of Exceedance • Inform IEC and EPD the causes and actions taken for the exceedances • Discuss with IEC for remedial action required • Ensure remedial measures are properly implemented • Assess effectiveness of Contractor’s remedial actions and keep IEC, EPD and informed of the results • Increase monitoring frequency to confirm findings • If exceedance stops, cease additional monitoring	• Verify the Notification of Exceedance • Check monitoring data submitted by ET and Contractor's working methods • Discuss amongst ET and Contractor on the potential remedial actions. • Review Contractor's remedial actions whenever necessary to assure their effectiveness • Supervise the implementation of remedial measures	• Take immediate action to avoid further exceedance • Submit proposals for remedial actions to IEC of notification • Implement the agreed proposals • Resubmit proposals if problem still not under control • Stop the relevant activity of works until the exceedance is abated

3 Noise Monitoring

3.1 Monitoring Requirement

3.1.1 In accordance with the EM&A manual, noise baseline monitoring shall be carried out at 2 monitoring stations NM1 and NM2 daily for a period of at least 14 consecutive days. The minimum logging interval shall be 30 minutes with average of 6 consecutive Leq 5 mins. L₁₀ and L₉₀shall also be measured at 5 mins intervals.

3.2 Monitoring Locations, Parameters and Frequency

3.2.1 According to the EM&A Manual, two monitoring stations namely NM1 and NM2 are selected for the baseline monitoring.

3.2.2 A baseline monitoring plan has been submitted to IEC and EPD including the proposal of change of monitoring locations. Due to limited access to the original monitoring locations at NM1 and NM2, the adjusted stations at NM1a and NM2a were agreed with IEC prior to the baseline monitoring. The noise monitoring locations are summarized in Table 3-1 and shown in Figure 2.

3.2.3 Noise baseline monitoring was conducted between 27 June 2022 and 17 July 2022 at NM1a and between 24 June 2022 and 17 July 2022 at NM2a. Due to adverse weather forecast, baseline noise monitoring was suspended from 1 July 2022 to 3 July 2022 at NM1a and NM2a. The detailed monitoring schedule is shown in Appendix A. The frequency and duration are shown in Table 3-2.

Table 3-1 Noise Monitoring Locations

Monitoring Station	Representative for	Type of Measurement
NM1a	Wo Keng Shan Tsuen	Free field
NM2a	Lin Ma Hang	Free field

*For Free Field measurement, +3dB(A) should be added to the measured results.

Table 3-2 Noise Baseline Monitoring Parameters, Frequency and Duration

Monitoring Station	Parameter	Frequency and Duration
NM1a and NM2a	L_Aeq (30mins) average of 6 consecutive Leq (5min); L10 (5min) & L90 (5min)	Daily for 14 consecutive days

3.3 Monitoring Equipment

3.3.1 Integrating Sound Level Meters (SLMs) was used for noise baseline monitoring. The SLM complied with International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1) specifications shall be used for carrying out noise monitoring. The accuracy of the SLM was checked using an acoustic calibrator generating a known sound pressure level at a known frequency. Measurements shall be accepted as valid only if the calibration level from prior to and after the noise measurement agrees to within 1.0dB.

3.3.2 A portable wind speed meter was used for measuring wind speeds in m/s.

3.3.3 Table 3-3 summarises the equipment that have been used in the baseline noise monitoring programme. The calibration certificates are shown in Appendix A.

Table 3-3 Noise Monitoring Equipment

Equipment	Model
Sound Level Meter	Rion NL-52 (S/N: 01010876, 01010877)
Acoustic Calibrator	Rion NC-75 (S/N: 34524163)
Anemometer	RS-90 (S/N: 210722168)

3.4 Monitoring Methodology

3.4.1 The details of noise measurement procedures are described as follows:

• Free-field measurements were made at the monitoring locations.

• For free field, the Sound Level Meter was set at a height of 1.2 m above the ground. The battery condition was checked to ensure the proper functioning of the meter.

• Parameters such as frequency weighting, the time weighting and the measurement time were set as follows:

• Frequency weighting: A

• Time weighting: Fast

• Measurement time: 5 minutes (Leq (30-min) would be determined for daytime noise by calculating the logarithmic average of six Leq (5min) data.)

• Prior to and after each noise measurement, the meter was calibrated using a Calibrator for 94.0 dB at 1000 Hz. If the difference in the calibration level before and after measurement was more than 1.0 dB, the measurement would be considered invalid and repeat of noise measurement would be required after recalibration or repair of the equipment.

• Noise measurement should be paused during periods of high intrusive noise if possible and observation shall be recorded when intrusive noise is not avoided.

• At the end of the monitoring period, the Leq, L10 and L90 shall be recorded. In addition, site conditions and noise sources should be recorded on a standard record sheet .

• All noise monitoring will be conducted with the wind speed not exceeding 5m/s and no gusts exceeding 10m/s.

3.5 Baseline Monitoring Result

3.5.1 The baseline noise monitoring results are summarized in Table 3-4, Table 3-5 and Table 3-6. The monitoring data together with graphical presentations are presented in Appendix C and Appendix D.

Table 3-4 Summary of Noise Monitoring Results during normal working hours (07:00-19:00, Monday to Saturday)

Noise Monitoring Station

Average Leq, 30min, dB(A) (Range)

Average L₁₀, 5min, dB(A) (Range)

Average L₉₀, 5min, dB(A) (Range)

NM1a

55.4

(42.7 – 72.5)

56.0

(41.6 – 78.0)

51.7

(38.0 – 77.3)

NM2a

54.5

(44.7 – 66.4)

54.5

(38.8 – 74.7)

49.0

(36.7 – 67.2)

Remark: * A correction of +3 dB(A) was made to the free field measurements

Table 3-5 Summary of Noise Monitoring Results during evening hours (19:00-23:00, Monday to Saturday)

Noise Monitoring Station

Average Leq 5min, dB(A) (Range)

Average L₁₀, 5min, dB(A) (Range)

Average L₉₀, 5min, dB(A) (Range)

NM1a

54.4

(46.4 – 72.2)

55.7

(47.5 – 73.2)

52.5

(39.2 – 67.3)

NM2a

53.3

(44.5 – 65.0)

54.7

(42.8 – 69.7)

50.4

(40 – 63.7)

Table 3-6 Summary of Noise Monitoring Results during night-time (23:00-07:00 on the next day, Sunday and Public Holiday)

Noise Monitoring Station

Average Leq 5 min, dB(A) (Range)

Average L₁₀, 5min, dB(A) (Range)

Average L₉₀, 5min, dB(A) (Range)

NM1a

53.6

(43.4 – 75.0)

55.0

(44.5 – 77.3)

51.3

(39.2 – 72.0)

NM2a

52.4

(41.3 – 68.2)

53.5

(41.3 – 72.7)

49.1

(38 – 64.4)

3.5.2 During the baseline monitoring period, the weather condition varied from sunny, cloudy, windy to rainy. No particular observations are identified near the monitoring stations during the baseline monitoring period. The noise monitoring results will be used as a reference of future impact monitoring period.

3.6 Action and Limit Level for Construction Noise

3.6.1 The criteria for action and limit levels for construction noise are defined in Table 3-7.

Table 3-7 Action and Limit Levels for Construction Noise

Time Period	Action Level	Limit Level
0700 - 1900 hours on normal weekdays	When one documented complaint is received	75dB(A)

If works are to be carried out during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority have to be followed.

3.7 Event and Action Plan

3.7.1 The action and limit levels for noise monitoring is defined in Table 3-7. Should non-compliance of the criteria occurs, action in accordance with the action plan in Table 3-8 shall be carried out.

4 Surface Water Monitoring

4.1 Monitoring Requirement

4.1.1 In accordance with the EM&A manual, baseline surface water quality monitoring was carried out at the designated surface water discharge points at WM1 for 3 days per week for 4 consecutive weeks prior to commencement of construction works of the Project. For WM2, further discussion has been made with EPD and EPD has agreed the surface water monitoring at WM2 shall be conducted for 3 days per week for 2 consecutive weeks during dry season prior to commencement of construction works.

4.2 Monitoring Locations, Parameters, Frequency and Duration

4.2.1 Baseline surface water monitoring was carried out between 10 June 2022 and 16 July 2022 at WM1 and between 29 October and 11 November 2022 at WM2. The monitoring locations are indicated in Table 4-1 and Figure 2.

4.2.2 The monitoring parameters, frequency and duration of surface water quality baseline monitoring are summarized in Table 4-2.

4.2.3 At the week of 27/6, surface water monitoring was planned to be conducted on 28/6, 30/6 and 1/7. Due to adverse weather, the surface water monitoring on 28/6 was rescheduled to 29/6. In addition, adverse weather was recorded from 30 June 2022 to 3 July 2022, the surface water monitoring was suspended due to safety concern. As such, additional monitoring was conducted on 14 July 2022 and 16 July 2022 at WM1. Due to adverse weather from 2 November to 4 November 2022, the surface water monitoring was suspended due to safety concern and resumed on 5 November 2022 at WM2. Detailed monitoring schedule is presented in Appendix A.

Table 4-1 Surface water quality monitoring locations

Monitoring Station	Location	Coordinates (HK Grid)
Monitoring Station	Location	Easting	Northing
WM1	Upstream of Lin Ma Hang River	836665	845020
WM2	Ping Yuen River	835592	844186

Table 4-2 Surface water quality monitoring Parameters, Frequency and Duration

Parameter

Frequency

Duration

pH, Electrical conductivity, DO, Turbidity, SS, Alkalinity, COD, BOD5, TOC, Ammonia-nitrogen, TKN, Nitrate, Sulphate, Sulphite, Phosphate, Chloride, Sodium, Mg, Ca, K, Fe, Ni, Zn, Mn, Cu, Pb, Cd, Coliform Count, Oil and Grease

3 days per week

4 consecutive weeks at WM1

2 consecutive weeks at WM2*

*Remark: The duration of surface water monitoring at WM2 is conducted in 2 consecutive weeks during dry season as agreed with the EPD. The monitoring parameters for WM2 are pH, DO, Turbidity and SS.

4.3 Monitoring Equipment

4.3.1 The measurements of pH, electrical conductivity (EC), DO, water temperature and air temperature were undertaken in situ. In situ monitoring instruments in compliance with the specifications listed under Section 5.5 of the EM&A Manual were used to undertake the surface water quality monitoring for the Project. Table 4-3 summarises the equipment used in the baseline surface water quality monitoring works. Copies of the calibration certificates are attached in Appendix B.

Table 4-3 Surface Water Quality Monitoring Equipment

Equipment

Model

Water Quality Meter

Horiba U-53 (S/N: S2A98W8H, THAUKESL)

YSI ProDSS (S/N: 22C106561)

Water Flow Meter

FP211 (S/N: 1513001493)

4.4 Summary of Surface Water Quality Monitoring Procedure

Operational/ Analytical Procedures

4.4.1 Water samples were collected from within 500 mm of the water surface. Water was collected by a small clean open-mouthed bucket with the lip pointing upstream. Usually, water was then transferred to the sample bottles until they were filled to the top with no remaining air space before the lid was securely screwed on. For samples that were preserved with acid or alkalis prior to transport to the laboratory, the samples bottles were filled to the level specified by the analytical laboratory.

4.4.2 Analysis shall be carried out in accordance with methods described in ASTM or APHA -AWWA-WEF Standard.

Laboratory Analytical Methods

4.4.3 The testing of parameters presented in Table 4-4 for all stations was conducted by ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066). Comprehensive quality assurance and control procedures were in place in order to ensure quality and consistency in results. The detection limits are provided in Table 4.4.

Table 4-4 Surface Water Monitoring Detection Limits and Limit of Reporting

Parameters	Detection Limit (in EM&A Manual)	Limit of Reporting	Method Reference
pH	0.1	0.1	APHA 4500 H+ B
Electrical conductivity	1 mS/cm	1 mS/cm	APHA 2510 B
Alkalinity	1 mg/L	1 mg/L	APHA 2320 B
COD	10 mg/L	5 mg/L	APHA 5220 C
BOD₅	3 mg/L	2 mg/L	APHA 5210 B
TOC	1 mg/L	1 mg/L	APHA 5310 B
SS	0.1 mg/L	0.1 mg/L	APHA 2540 D
Ammonia-nitrogen	0.2 mg/L	0.01 mg/L	APHA 4500 NH3 G
TKN	0.4 mg/L	0.1 mg/L	APHA 4500Norg: D
Nitrate	0.5 mg/L	0.01 mg/L	APHA 4500 NO3 I
Sulphate	5 mg/L	1 mg/L	USEPA 375.4
Sulphite	2 mg/L	2 mg/L	APHA 4500 SO3 B
Phosphate	0.01 mg/L	0.01 mg/L	APHA 4500-P B & F
Chloride	0.5 mg/L	0.5 mg/L	USEPA 325.1
Sodium	50 mg/L	50 mg/L	USEPA 6010C
Mg	50 mg/L	50 mg/L	USEPA 6010C
Ca	50 mg/L	50 mg/L	USEPA 6010C
K	50 mg/L	50 mg/L	USEPA 6010C
Fe	50 mg/L	10 mg/L	USEPA 6010C
Ni	1 mg/L	1 mg/L	USEPA 6020A
Zn	10 mg/L	10 mg/L	USEPA 6020A
Mn	1 mg/L	1 mg/L	USEPA 6020A
Cu	1 mg/L	1 mg/L	USEPA 6020A
Pb	1 mg/L	1 mg/L	USEPA 6020A
Cd	0.2 mg/L	0.2 mg/L	USEPA 6020A
Coliform Count	1 cfu/ 100mL	1 cfu/ 100mL	DoE section 7.8, 7.9.4.1 & 3
Oil and Grease	5 mg/L	5 mg/L	APHA 5520 B

QA/ QC Requirements

4.4.4 All in situ monitoring instruments were checked, calibrated and certified by a laboratory accredited under HOKLAS or other international accreditation scheme before use, and subsequently re-calibrated at the intervals according to manufacturer’s requirement throughout all stages of the surface water quality monitoring programme. Responses of sensors and electrodes were checked with certified standard solutions before each use. Calibration for a DO meter was carried out before measurement according to the instruction manual of the equipment model. For the on-site calibration of field equipment, the requirements of the BS 1427:2009, "Guide to on-site test methods for the analysis of waters" was observed.

Decontamination Procedures

4.4.5 Water sampling equipment used during the course of the monitoring programme was decontaminated by manual washing and rinsed with clean distilled water after each sampling location.

Sampling Management and Supervision

4.4.6 All sampling bottles were labelled with the sample ID (including the indication of sampling station), laboratory number and sampling date. Water samples were dispatched to the testing laboratory for analysis as soon as possible after the sampling. All samples were stored in a cool box and kept at less than 4°C but without frozen. All water samples were handled under chain of custody protocols and relinquished to the laboratory representatives at locations specified by the laboratory. The laboratory determination works started within 24 hours after collection of water samples.

Quality Control Measures for Sample Testing

4.4.7 The samples testing was performed by ALS Technichem (HK) Pty Ltd. The following quality control programme was performed by the laboratory for every batch of 20 samples:

· One method blank; and

· One sample duplicate.

4.5 Baseline Monitoring Results

4.5.1 Baseline surface water quality monitoring was conducted at WM1 between 10 June 2022 and 16 July 2022 Adverse weather was observed from 30 June 2022 to 3 July 2022 and typhoon signal no. 8 was hoisted on 1 July 2022. Surface water quality monitoring was suspended from 30 June to 3 July and resumed on 4 July 2022 at WM1.

4.5.2 Baseline surface water quality monitoring was conducted between 29 October 2022 and 11 November 2022 at WM2 inclusive of both days. Due to typhoon signal no. 8 as hoisted on 2 November 2022 and adverse weather from 3 November to 4 November 2022, surface water monitoring was suspended from 2 November to 4 November and resumed on 5 November 2022 at WM2.

4.5.3 The detailed monitoring schedule is shown in Appendix A. The monitoring results at each monitoring station and graphical presentations of surface water quality (DO, SS and Turbidity) at the monitoring stations are given in Appendix C and Appendix D.

4.6 Action and Limit Level for Surface Water Monitoring

4.6.1 The criteria of action and limit levels for surface water monitoring are defined in Table 4-5.

Table 4-5 Criteria for Action and Limit Levels for Surface Water Quality

Parameter	Action	Limit
DO in mg L^-1	5 percentile of baseline data	4 mg L^-1 or 1%-ile of baseline data
pH	95 percentile of baseline data	99 percentile of baseline
Turbidity in NTU	95 percentile of baseline data	99 percentile of baseline
SS in mg L^-1	95 percentile of baseline data	99 percentile of baseline

Notes

1. For DO, non-compliance of the water quality limits occurs when monitoring result is lower than the limits

2. For turbidity, SS, non-compliance of the water quality limits occurs when monitoring result is higher than the limits.

3. For pH, non-compliance of the water quality limits occurs when monitoring result is outside the specified range

4.6.2 Based on the criteria listed in Table 4-5, the action and limit levels for surface water quality are determined in Table 4-6 and Table 4-7.

Table 4-6 Action and Limit levels for Surface Water Quality for WM1

Parameter	Action	Limit
DO in mg L^-1	7.4	4.0
pH	7.7	7.8
Turbidity in NTU	9.2	9.5
SS in mg L^-1	9.7	11.4

Table 4-7 Action and Limit levels for Surface Water Quality for WM2

Parameter	Action	Limit
DO in mg L-1	5.0	4.0
pH	7.6	7.7
Turbidity in NTU	108.3	108.9
SS in mg L-1	94.5	94.7

4.7 Event and Action Plan

4.7.1 The action and limit levels for surface water monitoring were defined in Table 4-6 and Table 4-7. Should non-compliance of the criteria occurs, action in accordance with the action plan in Table 4-8 shall be carried out.

Table 4-8 Event and Action Plan for Water Quality

Event

IEC

Contractor

Action level being exceeded by one sampling day

• Repeat in situ measurement to confirm findings

• Identify source(s) of impact

• Prepare Notification of Exceedance

• Inform IEC and Contractor

• Check monitoring data, all plant, equipment and Contractor’s working methods

• Repeat measurement on next day of exceedance

• Verify Notification of Exceedance

• Check monitoring data and Contractor’s working methods

• Rectify unacceptable practice

• Amend working methods if appropriate

Action level being exceeded by two or more consecutive sampling days

• Repeat in situ measurement to confirm findings

• Identify source(s) of impact

• Prepare Notification of Exceedance

• Inform IEC and Contractor

• Check monitoring data, all plant, equipment and Contractor’s working methods

• Discuss with Contractor and IEC for remedial measures

• Ensure mitigation measures are implemented

• Increase the monitoring frequency to daily until no exceedance of Action level

• Repeat measurement on next day of exceedance

• Verify Notification of Exceedance

• Check monitoring data and Contractor's working method

• Discuss with ET and Contractor on possible remedial actions

• Review the proposed mitigation measures

• Supervise the implementation of mitigation measures

• Submit proposal of additional mitigation measures to IEC of notification

• Implement the agreed mitigation measures

• Amend proposal if appropriate

Limit Level being exceeded by one sampling day

• Repeat in situ measurement to confirm findings

• Identify source(s) of impact

• Prepare Notification of Exceedance

• Inform IEC and Contractor;

• Check monitoring data, all plant, equipment and Contractor's working methods

• Discuss mitigation measures with IEC and Contractor

• Ensure mitigation measure are implemented

• Verify Notification of Exceedance

• Check monitoring data submitted By ET and Contractor’s working method

• Discuss with ET and Contractor on possible remedial actions

• Review the proposed mitigation measures

• Supervise the implementation of mitigation measures

• Critically review the working method

• Rectify unacceptable practice

• Take immediate corrective actions to avoid further exceedance

• Submit proposal of mitigation measures to IEC

• Implement the agreed mitigation measures

•

~~Event~~

~~IEC~~

~~Contractor~~

~~Limit Level being exceeded by one sampling day~~

• ~~Repeat in situ measurement to confirm findings~~

• ~~Identify source(s) of impact~~

• ~~Prepare Notification of Exceedance~~

• ~~Inform IEC and Contractor;~~

• ~~Check monitoring data, all plant, equipment and Contractor's working methods~~

• ~~Discuss mitigation measures with IEC and Contractor~~

• ~~Ensure mitigation measure are implemented~~

• ~~Verify~~ ~~Notification of Exceedance~~

• ~~Check monitoring data submitted By ET and Contractor’s working method~~

• ~~Discuss with ET and Contractor on possible remedial actions~~

• ~~Review the proposed mitigation measures~~

• ~~Supervise the implementation of mitigation measures~~

• ~~Critically review the working method~~

• ~~Rectify unacceptable practice~~

• ~~Take immediate corrective actions to avoid further exceedance~~

• ~~Submit proposal of mitigation measures to IEC~~

• ~~Implement the agreed mitigation measures~~

•

Limit level being exceeded by two or more consecutive sampling days

• Repeat in situ measurement to confirm findings

• Identify source(s) of impact

• Prepare Notification of Exceedance

• Inform IEC, contractor and EPD

• Check monitoring data, all plant, equipment and Contractor's working methods

• Discuss mitigation measures with IEC and Contractor

• Ensure mitigation measure are implemented

• Verify Notification of Exceedance

• Check monitoring data submitted by ET and Contractor’s working method

• Discuss with ET and Contractor on possible remedial actions

• Review the proposed mitigation measures

• Supervise the implementation of mitigation measures

• Critically review the working method

• Rectify unacceptable practice

• Take immediate corrective actions to avoid further exceedance

• Submit proposal of mitigation measures to IEC

• Implement the agreed mitigation measures

• Resubmit proposals if problem still not under control

• Slow down or to stop relevant activity until exceedance is abated

Figure 1	Location of the Project Site
Figure 2	Baseline Monitoring Locations

Appendix A	Baseline Monitoring Schedule
Appendix B	Calibration Certificates for Baseline Dust, Noise and Surface Water Monitoring
Appendix C	Baseline Monitoring Results for Dust, Noise and Surface Water Monitoring
Appendix D	Graphical Presentation of baseline monitoring
Appendix E	Photo Records of the monitoring locations
Appendix F	Meteorological Data