EXECUTIVE SUMMARY

The Project, Lei Yue Mun Waterfront Enhancement Project, is a Designated Project under the Environmental Impact Assessment Ordinance (Cap. 499) (EIAO) and is currently governed by a Environmental Permit (EP No. EP-564/2018) for the construction and operation of the Project.

In accordance with the approved Environmental Monitoring and Audit Manual (EM&A Manual) for the Project, baseline environmental monitoring for marine water quality, noise and ecology (Coral) should be conducted prior to the commencement of construction works. Pursuant to EP Condition 3.3, Baseline Monitoring Report shall be submitted to the Director of Environmental Protection at least 2 weeks before the commencement of construction of the Project. As the construction of land-based works and marine-based works are tentatively scheduled to commence in May 2021 and July 2021 respectively, baseline monitoring for marine water quality, noise and ecology were conducted according to the EM&A Manual before the commencement of construction works at selected locations at and around Lei Yue Mun (LYM).

The baseline monitoring for noise was carried out between 27 January 2021 and 10 February 2021 at the monitoring locations sited at LYM. Baseline noise monitoring was conducted for daytime (0700 – 1900 hrs), evening time (1900 – 2300 hrs) and night time (2300 – 0700 hrs). Data collected was reviewed and analysed to establish the background noise levels at the four monitoring locations. The below Table A1 summarized the results of the baseline monitoring.

Table A1 Summary of Baseline Noise Monitoring Results

Location	Noise in dB(A)
	Average_NOTE1				Range
	L_{eq 30min} Daytime (7:00-19:00 on normal weekdays)	L_{eq 5min} Daytime (7:00-19:00 on Sunday and general holidays)	L_{eq 5min} Evening time (19:00-23:00)	L_{eq 5min} Night time (23:00-07:00)	L_{eq 30min} Daytime (7:00-19:00 on normal weekdays)	L_{eq 5min} Daytime (7:00-19:00 on Sunday and general holidays)	L_{eq 5min} Evening time (19:00-23:00)	L_{eq 5min} Night time (23:00-07:00)
NM1	62.4	63.4	56.3	53.9	37.2-72.9	46.4-78.1	30.5-70	33.5-70.1
NM2-A	60.2	61.3	56.3	52.9	42.3-76.6	41.2-71.8	41.1-73.3	34.4-71.9
NM3	65.3	60.9	58.4	56.5	55.8-78.2	55-66.5	53.4-69.1	51.8-67.4
NM4	57.5	56.6	54.6	50.6	47.9-69	46.7-70.3	43.3-61.8	33.8-66

NOTE 1: The calculated logarithm average of all L_{eq 5min}from field measurement during the baseline period

Baseline marine water quality monitoring was carried out between 15 April 2021 and 11 May 2021 at six water quality monitoring locations. Data collected was reviewed and analysed to establish the background water quality at the six monitoring locations. The below Table A2 summarized the results of the baseline monitoring.

Table A2 Summary of Baseline Water Quality Monitoring Results

Location		Parameters
		Salinity (ppt)	Dissolved Oxygen (mg/L) _note_i		pH	Turbidity (NTU)	Suspended solids (mg/L)	Temperature (°C)
		Salinity (ppt)	Surface & Middle	Bottom	pH	Turbidity (NTU)	Suspended solids (mg/L)	Temperature (°C)
C1	Avg.	29.44	8.97	8.89	8.29	6.36	3.8	27.07
	Min.	28.43	7.64	7.36	7.93	4.98	2.5	25.26
	Max.	31.06	10.27	10.48	8.73	7.11	18.2	29.60
C2	Avg.	29.43	8.94	8.90	8.30	7.08	4.0	27.09
	Min.	28.33	7.42	7.51	7.91	5.61	2.5	25.11
	Max.	31.13	10.15	10.45	8.77	8.01	28.8	30.15
M1	Avg.	29.50	9.01	8.97	8.30	3.30	4.0	27.09
	Min.	28.37	7.83	7.62	7.95	2.52	2.5	25.18
	Max.	30.95	10.52	10.29	8.76	4.00	20.0	29.96
M2	Avg.	29.45	8.95	8.87	8.29	5.14	4.6	27.07
	Min.	28.40	7.49	7.55	7.94	3.91	2.5	25.30
	Max.	31.07	10.60	10.33	8.74	6.15	23.7	29.63
M3	Avg.	29.41	8.97	8.99	8.31	3.13	3.9	27.06
	Min.	28.34	7.76	7.59	7.96	1.92	2.5	25.19
	Max.	31.19	10.56	10.37	8.65	3.81	10.8	29.89
M4	Avg.	29.41	8.96	8.92	8.30	4.06	4.0	27.10
	Min.	28.50	7.73	7.68	7.96	2.87	2.5	25.29
	Max.	30.82	10.47	10.26	8.72	4.90	17.5	30.18

The coral baseline survey consists of coral mapping, which was carried on 5 March 2021 and 6 March 2021 at the coastal area of LYM and the survey result has been reported in the Coral Baseline Survey Report and Coral Translocation Plan, which were noted with no further comments from consultation with AFCD and submitted to EPD on 15 April 2021.

1. Introduction

1.1. Background

Civil Engineering and Development Department (CEDD) has contracted Concentric - Hong Kong River Joint Venture (CHKRJV) to carry out the Construction of Lei Yue Mun Public Landing Facility under Contract No. CV/2020/09; and Architectural Services Department (ArchSD) has contracted Milestone Builder Engineering Limited to carry out the development of a waterfront promenade and related improvement works under Contract No. SS J521 for the Lei Yue Mun Waterfront Enhancement Project (the Project).

Acuity Sustainability Consulting Limited (ASCL) is commissioned by CEDD 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-219/2018) 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 under Contract No. PI 2/2020.

Pursuant to the Environmental Impact Assessment Ordinance (EIAO), the Director of Environmental Protection granted the Environmental Permit (No. EP-564/2018) to CEDD for the Project.

1.2. Project Description

Since 2000, the Tourism Commission (TC) has been implementing the Tourism District Enhancement Programme to enrich Hong Kong’s appeal to visitors. Lei Yue Mun (LYM), being one of the most popular tourist attractions in Hong Kong for its pleasant seaside ambience and excellent seafood, had been identified to accord priority for improvement under the Programme. The TC completed several initial minor improvements along the LYM waterfront in 2003 and planned to further improve the facilities along the LYM waterfront area. The Project consists of two components:

· Construction of a Public Landing Facility and Improvement Works to Existing Lookout Points and Viewing Platform; and

· Development of a Waterfront Promenade and Related Improvement Works.

1.3. Purpose of the Report

According to the EM&A Manual for the Project, baseline environmental monitoring for noise and water quality should be conducted prior to the commencement of construction works.

According to Cl. 1.5B of the Contract No. PI 2/2020 Specification for the Project, coral baseline survey and translocation of coral colonies at direct impact sites should be conducted prior to the commencement of construction works.

The EM&A requirements for baseline monitoring are set out in the EM&A Manual and Contract Specification. Environmental aspect of construction noise, water quality and ecology (Coral) were identified as the key issues requiring implementation of monitoring programme during the construction phase of the Project.

This report presents the monitoring methodology and findings for the baseline noise and water quality monitoring of the Project. Details of monitoring methodology and findings for coral were presented in a separate submission, namely Coral Baseline Survey Report, prepared by the coral specialist.

1.4. Report Structure

This Baseline Monitoring Report comprises the following sections:

· Section 1 introduces the background of the Project and purpose of this Report;

· Section 2 presents the baseline monitoring methodologies, requirements, results, influencing factors, as well as determination of the action and limit levels of noise; and

· Section 3 presents the baseline monitoring methodologies, requirements, results, influencing factors, as well as determination of the action and limit levels of marine water quality; and

· Section 4 concludes the findings of baseline monitoring.

2. Noise

2.1. Baseline Monitoring Criteria

Baseline noise monitoring shall be carried out daily in all identified monitoring stations for 2 weeks prior to the commissioning of the construction works. The baseline noise levels should be measured for a continuous period of at least 14 consecutive days at a minimum logging interval of 30 minutes for daytime (between 0700 and 1900 hours of normal weekdays) and 15 minutes (as three consecutive L_{eq, (5 minutes)} readings) for evening time (between 1900 and 2300 hours on normal weekdays), general holidays including Sundays (between 0700 and 2300 hours) and night-time (between 2300 and 0700 on all days). A schedule of the baseline monitoring shall be submitted to the IEC for approval before the monitoring starts.

There should not be any construction activities in the vicinity of the monitoring stations during the baseline monitoring. Any non-project related construction activities in the vicinity of the monitoring stations during the baseline monitoring should be noted and the source and location of such activities should be recorded.

In exceptional cases, when baseline monitoring data obtained are insufficient or questionable, the ET should liaise with the IEC and EPD to agree on an appropriate set of data to be used as the baseline reference.

Table 2.1 summarizes the monitoring parameters, frequency and duration of the baseline noise monitoring.

Table 2.1 Noise Monitoring Parameters, Time, Frequency and Duration

Time

Duration

Interval

Parameters

Daytime:

0700-1900 hrs

Evening time:

1900-2300 hrs

Night time:

2300-0700 hrs

Daily for at least 14 consecutive days

Continuously in

L_{eq 5}_min/L_{eq 30min}(average of 6 consecutive L_{eq 5min})

L_eq _5min, L_eq _30min,

L₁₀ & L₉₀

2.2. Monitoring Equipment

As referred to in the Technical Memorandum (TM) issued under the NCO, sound level meters in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1) specifications shall be used for carrying out the noise monitoring. Immediately prior to and following each noise measurement the accuracy of the sound level meter shall be checked using an acoustic calibrator generating a known sound pressure level at a known frequency. Measurements should be accepted as valid only if the calibration level from before and after the noise measurement agrees to within 1.0 dB. The microphone head of the sound level meter and calibrator were cleaned with a soft cloth at quarterly intervals. The sound level meter and calibrator were checked and calibrated at yearly intervals

Noise measurements should not be made in 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.

The ET is responsible for the provision of the monitoring equipment to ensure that sufficient noise measuring equipment and associated instrumentation are available for carrying out the baseline monitoring, regular impact monitoring and ad hoc monitoring. All the equipment and associated instrumentation shall be clearly labelled.

Equipment used in the baseline noise monitoring programme is summarized in Table 2.2 below. Calibration certificates for the noise monitoring equipment are attached in Appendix A.

Table 2.2 Baseline Noise Monitoring Equipment

Equipment	Brand and Model	Serial No.
Sound Level Meter	Scarlet ST-11D	820204
		820197
		820346
		820200
Sound Level Meter Calibrator	Scarlet ST-120	200504747

2.3. Monitoring Location

According to the environmental findings detailed in the EIA report, the designated locations for the construction noise monitoring are listed in Table 2.3.

Table 2.3 Original Noise Monitoring Stations for Baseline and Impact Monitoring

Station	Noise Sensitive Receiver	Monitoring Location	Position
NM1	Village house in Lei Yue Mun Hoi Pong Road Central	Pedestrian Road on Ground Floor	1 m from facade
NM2	No.81, Lei Yue Mun Hoi Pong Road East	Pedestrian Road on Ground Floor	1 m from facade
NM3	Jockey Club Lei Yue Mun Plus	Fenced Road on Ground Floor	1 m from facade
NM4	No. 21C, Lei Yue Mun Hoi Pong Road East	Fenced Road on Ground Floor	1 m from facade

The original construction noise monitoring station NM2 was selected at the façade of No. 81 of Lei Yue Mun Hoi Pong Road East. However, the residents of the premises at No. 81 of Lei Yue Mun Hoi Pong Road East do not allow the setting up of the construction noise monitoring station NM2. No. 79B, Lei Yue Mun Hoi Pong Road East, was proposed as the alternative noise monitoring location for set up of construction noise monitoring station named as NM2-A.

A Proposal for Alternative Noise Monitoring Station, which was certified by the ET Leader and verified by the IEC, has been prepared to conclude that the alternative construction noise monitoring station NM2-A could conform to relevant requirements as set out in the EM&A Manual, namely:

· locate close to the major site activities which are likely to have noise impacts;

· locate close to the most affected existing NSRs; and

· take into account the possibility of minimizing disturbance to occupants at the NSRs during monitoring.

The Proposal for Alternative Noise Monitoring Station NM2-A has been approved by EPD on 16 April 2021.

The latest locations for the construction noise monitoring are listed in Table 2.4.

Table 2.4 Updated Noise Monitoring Stations for Baseline and Impact Monitoring

Station	Noise Sensitive Receiver	Monitoring Location	Position
NM1	Village house in Lei Yue Mun Hoi Pong Road Central	Pedestrian Road on Ground Floor	1 m from facade
NM2-A	No.79B, Lei Yue Mun Hoi Pong Road East	Pedestrian Road on Ground Floor	1 m from facade
NM3	Jockey Club Lei Yue Mun Plus	Fenced Road on Ground Floor	1 m from facade
NM4	No. 21C, Lei Yue Mun Hoi Pong Road East	Fenced Road on Ground Floor	1 m from facade

The location of all original construction noise monitoring stations and the alternative construction noise monitoring station are shown in Figure 2.1.

Figure 2.1 Noise monitoring locations at LYM

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. Table 2.5 showed photographs and indications of the proposed position of sound level meters to be placed for the baseline and impact monitoring.

Table 2.5 Photo of Proposed Sound Level Meter Position at Noise Monitoring Stations

ID	Sound Level Meter Postion	Direction of Photo
NM1
NM2-A
NM3
NM4

2.4. Baseline Monitoring Methodology

Baseline noise monitoring was conducted between 27 January 2021 and 10 February 2021 (inlcuding Sunday and general holidays). At each designated monitoring location, measurements of 5-minutes A-weighted equivalent sound pressure level [“L_{eq 5min}”] was conducted continuously, along with the measurements of L₁₀and L₉₀ for each of the 5-minutes measurement. The measurement results are sorted in four time categories, namely (i) Daytime (0700-1900) on normal weekdays (not being a Sunday or general holidays), (ii) Daytime (0700-1900) on Sunday or general holidays (iii) Evening time (1900-2300), and (iv) Night time (2300-0700). For measurement during Daytime of normal weekdays, 30-minutes A-weighted equivalent sound pressure level (L_{eq 30min}), calculating from logarithm average of 6 consecutive L_{eq 5min} from field measurement, shall be used as the monitoring parameter. For measurement during Daytime of Sunday or general holiday, Evening time and Night time, L_{eq 5min} shall be used as the monitoring parameter to align with the stipulated parameter in Technical Memorandum on Noise from Construction Work Other Than Percussive Piling as reference.

The monitoring procedures are as follows:

· The microphone head of the lead level meter was normally positioned 1m exterior of the noise sensitive façade and lowered sufficiently so that the building’s external wall acts as a reflecting surface.

· The monitoring locations should normally be made at a position 1.2m above the ground.

· The battery condition was checked to ensure good functioning of the meter.

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

o Frequency weight: A

o Time weighting: Fast

o Measurement time: 5 minutes

· Prior to and after noise measurement, the meter was calibrated using the calibrator for 94.0 dB at 1000Hz. If the difference in the calibration level before and after measurement is more than 1.0 dB, the measurement was considered invalid and repeat of noise measurement was required after re-calibration or repair of the equipment.

· Noise monitoring was carried out continuously for 24 hours during the measurement period with the baseline sound level meter system. At the end of the monitoring period, noise levels in term of Leq, L10, and L90 were recorded. In addition, site conditions and noise sources were recorded when the equipment were checked and inspected.

· All the monitoring data within the sound level meter system was downloaded through the computer software.

2.5. Results and Observations

Baseline monitoring for noise impact was conducted from 27 January 2021 to 10 February 2021. The baseline noise levels at Noise Monitoring Stations at LYM (i.e. NM1 to NM4) are summarized in Table 2.6. Details of noise monitoring results are presented in Appendix B.

During the baseline monitoring, no construction activities of the Project was conducted in the vicinity of the monitoring locations and in the project site.

Construction activities from another DSD project was noted near NM3 and NM4. No other major noise source was noted. Weather condition of the whole baseline monitoring period were fine and sunny, except there was raining on 10 February 2021 since 7:00am. As raining might affect the monitoring results, thus the noise data for period of time with raining are discarded. Extracts of Meteorological Observations for Hong Kong available from Hong Kong Observatory, which reflected the weather summary of the baseline noise monitoring period, are presented in Appendix C.

During the continuous measurements of L_{eq 5min}, data for some timeslots were not recorded due to mainly 2 reasons: (1) time spent for replacing of batteries and logging of data; and (2) unexpected power failure of meter. Despite the above, at least one set of daytime (L_{eq 30min}during 0700-1900), evening time (L_eq
5minduring 1900-2300) and night time (L_{eq 5min}during 2300-0700) monitoring data were recorded for each monitoring day for the whole baseline period. Thus the monitoring data is considered adequate.

Table 2.6 Summary of Baseline Noise Monitoring Results

Location	Noise in dB(A)
	Average_NOTE1				Range
	L_{eq 30min} Daytime (7:00-19:00 on normal weekdays)	L_{eq 5min} Daytime (7:00-19:00 on Sunday and general holidays)	L_{eq 5min} Evening time (19:00-23:00)	L_{eq 5min} Night time (23:00-07:00)	L_{eq 30min} Daytime (7:00-19:00 on normal weekdays)	L_{eq 5min} Daytime (7:00-19:00 on Sunday and general holidays)	L_{eq 5min} Evening time (19:00-23:00)	L_{eq 5min} Night time (23:00-07:00)
NM1	62.4	63.4	56.3	53.9	37.2-72.9	46.4-78.1	30.5-70	33.5-70.1
NM2-A	60.2	61.3	56.3	52.9	42.3-76.6	41.2-71.8	41.1-73.3	34.4-71.9
NM3	65.3	60.9	58.4	56.5	55.8-78.2	55-66.5	53.4-69.1	51.8-67.4
NM4	57.5	56.6	54.6	50.6	47.9-69	46.7-70.3	43.3-61.8	33.8-66

NOTE 1: The calculated logarithm average of all L_{eq 5min}from field measurement during the baseline period

2.6. Action and Limit Levels

The Action/Limit Levels 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 2.7.

Table 2.7 Action and Limit Levels for Noise

Monitoring Location	Action Level	Limit Level in dB(A)
	0700-1900 hours on Normal Weekdays
NM3	When one documented complaint is received	70 dB(A) for educational premises during normal teaching periods and 65 dB(A) during examination periods
NM1, NM2-A and NM4		75 dB(A) for residential premises and places of public worship

Remark: If the 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. Water Quality

3.1. Baseline Monitoring Criteria

In accordance with the recommendations of the EIA, marine water quality monitoring is required during the dredging and filling operation in the construction 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 to identify whether the potential exists for any indirect impacts to occur to nearby 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.

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.

3.2. 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	mg/L	-
Laboratory measurements
Suspended Solids	mg/L	SS

In addition to the water quality parameters, other relevant data will also be measured and recorded in data record sheet, including the location of the sampling stations, water depth, time, weather conditions, sea conditions, tidal stage, special phenomena and work activities undertaken around the monitoring and works area that may influence the monitoring results.

3.3. 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).

pH Measurement Instrument - The instrument should consist of a potentiometer, a glass electrode, a reference electrode and a temperature-compensating device. It should be readable to 0.1 pH in a range of 0 to 14. Standard buffer solutions of at least pH 7 and pH 10 should be used for calibration of the instrument before and after use.

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.

Sample Containers and Storage - Water samples for SS should be stored in high density polythene bottles with no preservative added, packed in ice (cooled to 4 °C without being frozen) and delivered to the laboratory and analysed as soon as possible after collection. Sufficient volume of samples should be collected to achieve the detection limit.

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.

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.

Calibration certificate for the water quality monitoring equipment is attached in Appendix D.

3.4. 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. Wet bulb calibration for a DO meter should be carried out before measurement at each monitoring location.

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.

3.5. 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 24 hours 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.

Detailed testing methods, pre-treatment procedures, instruments use, Quality Assurance / Quality Control (QA/QC) details (such as blank, spike recovery, number of replicate samples per batch, etc.), detection limit and accuracy were submitted to EPD for approval on 3 February 2021 prior to the commencement of monitoring programme. EPD may also request the laboratory to carry out analysis of known standards provided by EPD for quality assurance. The QA / QC shall be in accordance with the requirements of HOKLAS or international accredited scheme. The QA/ QC results shall be reported. The testing methods and related proposal were checked and certified by IEC before submission to EPD for approval.

Parameters for laboratory measurements, their standard methods and their detection limits are presented in Table 3.2.

Table 3.2 Laboratory measurements, standard methods and corresponding detection limits of marine water quality monitoring

Parameter	Standard Method	Detection Limit	Accuracy
Suspended Solids (mg/L)	APHA 2540D	1.0*	±17%

Remark *: Albeit the selected HOKLAS accredited laboratories’ standard testing method of total suspended solid according to APHA Method 2540D is capable of reporting the results to 1 mg/L, the laboratory advised that results reported between 1 and 2 mg/L shall be considered to be used as reference value and receive no HOKLAS accreditation for this particular range of result

The HOKLAS Laboratory Certificate is attached in Appendix E.

3.6. Monitoring Locations

The water quality monitoring locations for baseline in accordance to the EM&A Manual are shown in Figure 3.1 and detailed in Table 3.3 below. Coordinates of monitoring station M1 from the EM&A Manual was found mistakenly placed, the updated coordinates showing the more accurate position of M1 according to Figure 5.1 of the EM&A Manual is shown in Table 3.3 below.

Figure 3.1 Locations of Water Quality Monitoring Stations

Table 3.3 Location of Baseline Water Quality Monitoring Station

Station	Easting	Northing	Description
C1	842134	816765	Control Station
C2	842946	816172	Control Station
M1	842605	816433	Coral Communities (Impact Monitoring Station)
M2	842329	816615	100m away from the dredging site (Impact Monitoring Station)
M3	842639	816410	Coral Communities (Impact Monitoring Station)
M4	842515	816878	Sam Ka Tsuen Typhoon Shelter (Impact Monitoring Station)

3.7. Sampling Frequency

Baseline conditions for water quality shall be established and agreed with the IEC and the EPD prior to the commencement of works. The purpose of the baseline monitoring is to establish ambient conditions prior to the commencement of the works and to demonstrate the suitability of the proposed impact and control monitoring stations. The baseline conditions shall normally be established by measuring the water quality parameters specified above.

Measurements should be taken at all designated monitoring stations, 3 days per week, at mid-flood and mid-ebb tides for at least 4 weeks prior to the commencement of dredging and sand filling works. There should not by any marine construction activities in proximity to the stations during the baseline monitoring. The interval between 2 sets of monitoring should not be less than 36 hours. Duplicate in-situ measurements and water sampling should be carried out in each sampling event. For selection of tides for in-situ measurement and water sampling, tidal range of individual flood and ebb tides should be not less than 0.5m.

In exceptional cases when insufficient baseline monitoring data or questionable results are obtained, the ET shall seek approval from the IEC and the EPD on an appropriate set of data to be used as baseline reference.

3.8. Sampling Depths & Replication

For baseline 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.

3.9. Results and Observations

The baseline marine water quality monitoring was conducted from 15 April 2021 to 11 May 2021 at all six monitoring stations (i.e. C1, C2, M1, M2, M3 and M4). The monitoring results are summarized in Table 3.4. Details of water quality monitoring results are presented in Appendix F.

There is no significant difference between control and impact stations for the parameters monitored.

As the southern water is affected by seasonal changes, the baseline water quality monitoring has not taken into account the seasonal variations for determination of Action and Limit Level for WQM. Therefore, during the future impact monitoring, the water quality monitoring results at the control points shall serve as a reference to determine if any elevated concentration of the monitored parameter is due to seasonal variation or project contribution. Revision on derivation criteria of the Action and Limit Level for WQM has therefore been made as specified in Table 3.6 of the report.

Table 3.4 Summary of Baseline Water Quality Monitoring Results

Location		Parameters
		Salinity (ppt)	Dissolved Oxygen (mg/L) _note_i		pH	Turbidity (NTU)	Suspended solids (mg/L)	Temperature (°C)
		Salinity (ppt)	Surface & Middle	Bottom	pH	Turbidity (NTU)	Suspended solids (mg/L)	Temperature (°C)
C1	Avg.	29.44	8.97	8.89	8.29	6.36	3.8	27.07
	Min.	28.43	7.64	7.36	7.93	4.98	2.5	25.26
	Max.	31.06	10.27	10.48	8.73	7.11	18.2	29.60
C2	Avg.	29.43	8.94	8.90	8.30	7.08	4.0	27.09
	Min.	28.33	7.42	7.51	7.91	5.61	2.5	25.11
	Max.	31.13	10.15	10.45	8.77	8.01	28.8	30.15
M1	Avg.	29.50	9.01	8.97	8.30	3.30	4.0	27.09
	Min.	28.37	7.83	7.62	7.95	2.52	2.5	25.18
	Max.	30.95	10.52	10.29	8.76	4.00	20.0	29.96
M2	Avg.	29.45	8.95	8.87	8.29	5.14	4.6	27.07
	Min.	28.40	7.49	7.55	7.94	3.91	2.5	25.30
	Max.	31.07	10.60	10.33	8.74	6.15	23.7	29.63
M3	Avg.	29.41	8.97	8.99	8.31	3.13	3.9	27.06
	Min.	28.34	7.76	7.59	7.96	1.92	2.5	25.19
	Max.	31.19	10.56	10.37	8.65	3.81	10.8	29.89
M4	Avg.	29.41	8.96	8.92	8.30	4.06	4.0	27.10
	Min.	28.50	7.73	7.68	7.96	2.87	2.5	25.29
	Max.	30.82	10.47	10.26	8.72	4.90	17.5	30.18

3.10. 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 3.5 below.

Table 3.5 Criteria of Action and Limit Levels for Water Quality

Parameters	Action	Limit
During the Dredging and Filling Operation of the Project
DO in mg/L	Surface and Middle ≤5%-ile of baseline data for surface and middle layers Bottom ≤5%-ile of baseline data for bottom layer	Surface and Middle ≤4 mg/L or 1%-ile of baseline data for surface and middle layers Bottom ≤2 mg/L or 1%-ile of baseline data for bottom layer
SS in mg/L (Depth-averaged)	≥ 95 %-ile of baseline data or 120% of control station’s SS at the same tide of the same day	≥ 99 %-ile of baseline data or 130% of control station’s SS at the same tide of the same day and specific sensitive receiver water quality requirements (e.g. required SS level for concerned seawater intakes)
Turbidity in NTU (Depth-averaged)	≥ 95 %-ile of baseline data or 120% of control station’s SS at the same tide of the same day	≥ 99 %-ile of baseline data or 130% of control station’s SS at the same tide of the same day

Based on the baseline water quality monitoring data and the derivation criteria specified above, the Action/Limit Levels have been derived and are presented in Table 3.6.

Table 3.6 Derived Action and Limit Levels for Water Quality

Parameters	Action	Limit
During the Dredging and Filling Operation of the Project
DO in mg/L	Surface and Middle 7.95 mg L^-1 Bottom 7.91 mg L^-1	Surface and Middle 4 mg L^-1 Bottom 2 mg L^-1
SS in mg/L (Depth-averaged)	6.73 mg L^-1 or 120% of control station’s SS at the same tide of the same day	17.60 mg L^-1 or 130% of control station’s SS at the same tide of the same day and specific sensitive receiver water quality requirements (e.g. required SS level for concerned seawater intakes)
Turbidity in NTU (Depth-averaged)	7.42 NTU or 120% of control station’s SS at the same tide of the same day compared with corresponding data from control station	7.79 NTU or 130% of control station’s SS at the same tide of the same day compared with corresponding data from control station

Notes:

i. "Depth-averaged" is calculated by taking the arithmetic means of reading of all three depths.

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

iii. For Turbidity and SS, non-compliance of the water quality limits occurs when monitoring result is higher than the limits.

4. Conclusion

4.1. Revision for Inclusion in the EM&A Documents

The baseline environmental monitoring was conducted according to the EM&A Manual for water quality, noise and ecology (Coral).

The monitoring methodology, parameters monitored, and monitoring locations are all in line with the EM&A Manual for the Project, except for the noise monitoring station NM2, which was replaced by the alternative noise monitoring location for set up of construction noise monitoring station named as NM2-A.

4.2. Noise

Baseline noise monitoring was carried out between 27 January 2021 and 10 February 2021 at four monitoring stations at LYM.

At all monitoring locations, the averaged baseline daytime noise monitoring results were well below the criteria of 75dB(A) for residential premises. No major noise sources affecting the noise background at the four monitoring stations were observed.

The Action Level of construction noise is based on documented valid complaints received, while the Limit Level for each monitoring location is set at a specific limit according to EIAO-TM and the EM&A Manual.

4.3. Water Quality

Baseline marine water quality monitoring was conducted between 15 April 2021 to 11 May 2021 at six monitoring stations (i.e. C1, C2, M1, M2, M3 and M4). All monitoring stations as specified in EM&A Manual were accessible and thus there is no revision for inclusion in the EM&A Manual.

No major pollution sources affecting the water quality baseline monitoring at the six monitoring stations were observed.

Action and Limit Levels were derived based on the baseline water quality monitoring results according to the EM&A Manual.

4.4. Ecology

Pre-construction Coral Mapping Survey was carried out on 5 March 2021 and 6 March 2021 at the coastal area of LYM, where the survey result has been reported in the Coral Baseline Survey Report and Coral Translocation Plan as Appendix G and Appendix H respectively.

Rev.	Description of Modification	Date
0	First issue for comments	19 Apr 2021
1	Revision according to IEC’s comments	20 Apr 2021
2	Supplemented Water Quality Section and Relevant Information	18 May 2021
3	Revision according to IEC’s comments	23 May 2021
4	Revision according to IEC’s comments	24 May 2021

Appendix A	Noise Monitoring Equipment Calibration Certificate
Appendix B	Baseline Noise Monitoring Data
Appendix C	Extract of Meteorological Observations for Hong Kong
Appendix D	Water Quality Monitoring Equipment Calibration Certificate
Appendix E	HOKLAS Laboratory Certificate
Appendix F	Baseline Water Quality Monitoring Data
Appendix G	Coral Baseline Survey Report
Appendix H	Coral Translocation Plan