Contents
2.3 Monitoring Parameters, Frequency and Duration
3.3 Monitoring Parameters, Frequency and Duration
3.5.2 Maintenance and Calibration
4.3 Monitoring Parameters, Frequency and Schedule
4.4.1 Operating/Analytical Procedures
4.4.2 Laboratory Analytical Methods
4.5 Quality Assurance (QA) / Quality Control (QC) Requirements
4.5.1 Calibration of In-situ Instruments
4.5.2 Sampling Management and Supervision
4.5.3 Quality Control Measures for Sample Testing
4.6 Baseline Monitoring Results
4.7.1 Tung Chung Stream (West) Stations
4.7.2 Tung Chung Stream (East) Stations
4.7.4 Implications on Action and Limit Levels
5.2 Setup of the Pre-construction Baseline Monitoring
5.2.2 Monitoring Period and Frequency
5.3 Action and Limit Levels and Event and Action Plan
6.3.1 Landscape Resources (LRs)
6.3.2 Landscape Character Areas (LCAs)
6.3.3 Visual Sensitive Receivers (VSRs)
Tables
Table 2.1: Baseline Air Quality Monitoring Stations
Table 2.2: Air Quality Monitoring Parameters, Frequency and Period
Table 2.3: 1-hour TSP Monitoring Equipment
Table 2.4: Summary of Baseline 1-hour TSP Monitoring Results
Table 2.5: Derivation of Action and Limit Levels for Air Quality
Table 2.6: Action and Limit Levels for 1-hour TSP
Table 2.7: Event and Action Plan for Construction Air Quality (Action Level)
Table 2.8: Event and Action Plan for Construction Air Quality (Limit Level) 10
Table 3.1: Baseline Noise Monitoring Stations
Table 3.2: Noise Monitoring Parameters, Frequency and Period
Table 3.3: Noise Monitoring Equipment
Table 3.4: Summary of Baseline Noise Monitoring Results – Normal Weekday Daytime (0700-1900 hrs)
Table 3.6: Summary of Baseline Noise Monitoring Results – Night-time (2300-0700 hrs)
Table 3.7: Action and Limit Levels for Construction Noise
Table 3.8: Event and Action Plan for Construction Noise
Table 4.1: Baseline Water Quality Monitoring Stations
Table 4.2: Water Quality Monitoring Parameters and Frequency
Table 4.3: Water Quality Monitoring Equipment
Table 4.4: Methods for Laboratory Analysis for Water Samples
Table 4.5: Updated Criteria for Action and Limit Levels for Impact Water Quality Monitoring
Table 4.6: Calculated Action and Limit Levels for Impact Water Quality Monitoring
Table 4.7: Event and Action Plan for Construction Water Quality
Table 5.1: Baseline Ecological and Water Quality Monitoring Stations (Eastern Tributary)
Table 5.2: Baseline Ecological and Water Quality Monitoring Stations (Western Tributary)
Table 5.3: Baseline Ecological and Water Quality Monitoring Schedule (Eastern Tributary)
Table 5.4: Baseline Ecological and Water Quality Monitoring Schedule (Western Tributary)
Table 5.5: Water Quality Monitoring Parameters and Testing Methods
Table 5.6: Physical Environment of the Monitoring Stations (Eastern Tributary)
Table 5.7: Physical Environment of the Monitoring Sations (Western Tributary)
Table 5.8: Cumulative Record of Aquatic Invertebrate Species (Eastern Tributary)
Table 5.9: Cumulative Record of Fish Species (Eastern Tributary)
Table 5.10 : Cumulative Record of Aquatic Invertebrate Species (Western Tributary)
Table 5.11: Cumulative Record of Fish Species (Western Tributary)
Table 5.12 : Occurrence Frequency of Aquatic Invertebrate Species Recorded (Eastern Tributary)
Table 5.13: Occurrence Frequency of Fish Species Recorded (Eastern Tributary)
Table 5.14: Occurrence Frequency of Aquatic Invertebrate Species Recorded (Western Tributary)
Table 5.15 : Occurrence Frequency of Fish Species Recorded (Western Tributary)
Table 5.16: Action and Limit Levels for Ecological Monitoring during Construction Phase
Table 5.19: Event and Action Plan for Action and Limit Level Exceedance in Aquatic Fauna
Table 6.1: Summary of Proposed Tree Treatment
Table 6.2: Proposed Tree Treatment for the Trees of Particular Interest
Mott MacDonald Hong Kong Limited (MMHK) was appointed by the Civil Engineering and Development Department (CEDD) under “Agreement No. CE 64/2020 (EP) – Environmental Team for Tung Chung New Town Extension (West) – Design and Construction” (hereinafter referred to as "the Assignment") to provide Environmental Team (ET) services regarding the Tung Chung New Town Extension (TCNTE) development in Tung Chung West (hereafter referred to as "the Project").
This Baseline Monitoring Report presents the monitoring works conducted in the period from July 2021 to September 2021 and May 2023 to March 2024 respectively, aims to establish the baseline levels of air quality (dust) and noise, water quality, ecology, and landscape and visual in the vicinity of the Project area, in accordance with the EP Condition 3.4 of the corresponding Environmental Permit (EP) (EP No. EP-519/2016) and Section 16.2 of the Updated Environmental Monitoring and Audit (EM&A) Manual for the TCNTE development dated May 2018 (hereinafter referred to as the “Updated EM&A Manual”).
Baseline Air Quality Monitoring
Baseline air quality (dust) monitoring (1-hour TSP) was carried out at the two designated monitoring locations (DM-5 and DM-6) from 9 to 17 July 2021 and from 21 to 25 July 2021. Monitoring was suspended on 18, 19 and 20 July 2021 due to a tropical cyclone. Overall, the baseline air quality results are considered representative to the ambient air quality of the Project and were used to establish the Action and Limit Levels for air quality (1-hour TSP levels).
Baseline Noise Monitoring
Baseline noise monitoring was carried out at the five designated monitoring locations (NMS-CA-5, NMS-CA-6, NMS-CA-7, NMS-CA-8 and NMS-CA-9). Monitoring was conducted at NMS-CA-5 and NMS-CA-6 from 10 to 17 July 2021 and from 20 to 27 July 2021, at NMS-CA-7 from 16 to 18 August 2021 and from 19 to 31 August 2021, and at NMS-CA-8 and NMS-CA-9 from 9 to 17 July 2021 and from 20 to 26 July 2021. Due to a tropical cyclone, monitoring at NMS-CA-5, NMS-CA-6, NMS-CA-8 and NMS-CA-9 was suspended on 17 July 2021 at 19:00 and resumed on 20 July 2021 at 23:00. Also, due to rainstorm, monitoring at NMS-CA-7 was suspended on 18 August 2021 at 23:00 and resumed on 19 August 2021 at 23:00.
During the baseline monitoring period, the major noise sources identified were:
● dog barking and bird chirping at NMS-CA-5;
● traffic noise, dog barking and bird chirping at NMS-CA-6;
● traffic noise, dog barking, bird chirping and excavator operating nearby at NMS-CA-7; and
● traffic noise at NMS-CA-8 and NMS-CA-9.
In general, the measured noise data at the five measured monitoring locations is considered representative of the baseline conditions for the Project.
Baseline Water Quality Monitoring
Baseline water quality monitoring was conducted at the seven designated monitoring stations presented in Table 2.5 of the Baseline Monitoring Proposal for Construction Phase Water Quality (TCW-WQM1, TCW-WQM2, TCW-WQM3A, TCW-WQM4, TCW-WQM5A, TCW-WQM6 and TCW-WQM7). Monitoring was conducted from 9 August 2021 to 3 September 2021. No observable pollution source was recorded at the monitoring stations, however the baseline monitoring results are found to be inadequate to represent the natural variations in ambient water quality levels. Therefore, it was considered prudent to incorporate additional baseline data to establish the Action and Limit Levels.
For supplementing Tung Chung Stream (West) (i.e. TCW-WQM2, TCW-WQM4 and TCW-WQM6) stations, and Tung Chung Stream (East) (i.e. TCW-WQM3A, TCW-WQM5A and TCW-WQM7) stations, EPD’s routine river water quality monitoring at Tung Chung River (TC1 at Tung Chung Stream West and TC2 at Tung Chung Stream East respectively) was used to supplement the baseline data for SS and Turbidity. For TCW-WQM1, no EPD routine marine water quality monitoring station at Tung Chung Bay is available, hence a supplementary 4-week baseline monitoring was carried out at TCW-WQM1 in October to November 2021 to extend the baseline monitoring dataset for deriving the Action and Limit Levels at TCW-WQM1.
Notwithstanding the above, the baseline conditions will be reviewed regularly and updated as appropriate, to demonstrate the continued suitability of the impact and control monitoring.
Baseline Ecological Monitoring
Eastern Tributary
Baseline ecological and water quality monitoring was conducted from 21 August 2020 to 14 July 2021 on a monthly basis at four (4) stations in River Park Study Area (RP1, RP2, RP3, RP4) for 12 months and three (3) stations in Public Works area (PW1, PW2, PW3) for 6 months covering wet season, as presented in Section 2.2 of the Detailed Ecological and Water Quality Monitoring Plan prepared by the Environmental Team of Tung Chung New Town Extension (East) ("TCE ET").
As presented in the Ecological and Water Quality Final Monitoring Report prepared by the TCE ET, for ecological monitoring, a total of 20 aquatic invertebrate and 28 fish species were recorded, among which one (1) aquatic invertebrate and three (3) fish species of conservation importance were recorded. For water quality monitoring, monitoring results are generally similar across the stations, except two (2) of which are located at the proximity of the estuary, showing higher levels in certain parameters due to the estuarine environment and tidal influence. Action and Limit Levels were established for taxa diversity, i.e. number of species, of fish and macroinvertebrate based on the baseline monitoring results. An Event and Action Plan was also proposed for exceedance of the Action and Limit Levels.
Western Tributary
Baseline ecological and water quality monitoring was conducted from 18 May 2023 to 12 March 2024 on a bi-monthly basis at three (3) stations in Public Works area (PW4, PW5, PW6) for 6 months covering wet season, as presented in Section 2.2 of the Baseline Monitoring Proposal (Ecological and Water Quality Monitoring Plan – Western Tributary of Tung Chung Stream) prepared by the Environmental Team of Tung Chung New Town Extension (West) ("TCW ET").
A total of 24 aquatic invertebrate and 18 fish species were recorded, among which one (1) aquatic invertebrate and four (4) fish species of conservation importance were recorded. For water quality monitoring, monitoring results exhibited overall similarities, except for one (1) monitoring station which showed a notable deviation in the form of high concentration of E. coli as recorded in September 2023 and November 2023 respectively. The relative high concentration of E. coli might due to the runoff from the village houses in Ngau Au at distance about 200 m. Action and Limit Levels were established for taxa diversity, i.e. number of species, of fish and macroinvertebrate based on the baseline monitoring results. An Event and Action Plan was also proposed for exceedance of the Action and Limit Levels.
Baseline Landscape and Visual Monitoring
Baseline landscape and visual monitoring was carried out in July 2021 to review the identified Landscape Resources, Landscape Character Areas and Visually Sensitive Receivers in the approved EIA report.
In general, the landscape and visual baseline conditions remain similar as that identified in the approved EIA report, except Ongoing Major Comprehensive Urban Development Landscape (LCA7b) identified at the EIA stage was recorded to have changed into Residential Urban Landscape (LCA13).
In addition, the distribution of tree groups within the Works Area remained unchanged since the EIA stage. No newly planted tree groups were identified within the Works Area, while no tree groups identified at the EIA stage have been removed.
Overall, there is no major change in the landscape and visual baseline conditions comparing to those during the EIA stage. Therefore, no additional landscape and visual mitigation measures other than those recommended in the approved EIA Report are required.
1
Introduction
1.1
Background
The Civil Engineering and Development Department (CEDD) and the Planning Department (PlanD) jointly commissioned Agreement No. CE 32/2011 (CE) "Planning and Engineering Study on the Remaining Development in Tung Chung" (hereafter referred to as the "P&E Study") in 2012, which aims at identifying development potentials and opportunities to expand Tung Chung New Town into a distinct community to meet housing, social, economic, environmental, and local needs. Under the P&E Study, various planning, engineering, and environmental studies (including a statutory Environmental Impact Assessment (EIA) Study) were carried out to formulate a development scheme, namely Tung Chung New Town Extension (TCNTE), to expand the existing Tung Chung New Town to the east and the west, i.e. Tung Chung East (TCE) and Tung Chung West (TCW) respectively.
The scope of the TCNTE development in TCW (hereafter referred to as "the Project") includes site formation and engineering infrastructure works for the developments of TCW, provision of a river park and revitalisation of an existing channelized section of Tung Chung Stream.
The P&E Study and specific works components in the TCNTE development plan are "Designated Projects" under Item 1 of Schedule 3 and numerous Items of Schedule 2, respectively, of the Environmental Impact Assessment Ordinance (EIAO). The EIA Report (Register No. AEIAR-196/2016) for the entire TCNTE development was approved with conditions on 8 April 2016 and the corresponding Environmental Permit (EP) (No. EP-519/2016) was issued on 9 August 2016.
Mott MacDonald Hong Kong Limited (MMHK) was appointed by CEDD under "Agreement No. CE 64/2020 (EP) – Environmental Team for Tung Chung New Town Extension (West) – Design and Construction" (hereinafter referred to as "the Assignment") to provide Environmental Team (ET) services regarding the Project. This Assignment commenced on 27 May 2021 and is scheduled to be completed in 129 months.
1.2
Purpose of the
Report
This Baseline Monitoring Report aims to present the baseline levels of air quality (dust) and noise, water quality, ecology, and landscape and visual in the vicinity of the Project area prior to the commencement of construction works of the Project, in accordance with EP Condition 3.4 of the corresponding Environmental Permit (EP) (EP No. EP-519/2016) and Section 16.2 of the Updated Environmental Monitoring and Audit (EM&A) Manual of the TCNTE development (hereinafter referred to as the "Updated EM&A Manual").
This report summarizes the schedules, locations, equipment, methodology, results and observations made during the baseline monitoring and establishes the Action and Limit Levels for the subsequent impact monitoring during the construction stage.
1.3
Structure of the Report
The structure of the report is as follows:
● Section 1 - Introduction, background, project description, purpose, and structure of the report.
● Section 2 - Air Quality – presents the methodology and findings of the baseline air quality monitoring.
● Section 3 - Noise – presents the methodology and findings of the baseline noise monitoring.
● Section 4 - Water Quality – presents the methodology and findings of the water quality monitoring.
● Section 5 - Ecology – presents the methodology and findings of the baseline ecological monitoring.
● Section 6 - Landscape and Visual – presents the methodology and findings of the baseline landscape and visual monitoring.
● Section 7 - Conclusions
2
Air Quality
2.1
Monitoring Requirement
According to the requirements in the Updated EM&A Manual, baseline air quality monitoring shall be carried out at designated monitoring locations for at least 14 consecutive days prior to the commencement of the construction works to obtain 1-hour Total Suspended Particulate (TSP) sample. The selected baseline monitoring stations should reflect baseline conditions at the impact stations. One-hour sampling should be done at least 3 times per day while the highest dust impact is expected. Further details of the baseline air quality monitoring are presented in the following sections.
2.2
Monitoring Locations
According to the Updated EM&A Manual, a total of six air quality monitoring stations are identified for the impact monitoring locations. Of these six air quality monitoring stations, two are located in the TCNTE possible development area (PDA) at Tung Chung West and are covered by this report. Locations of the baseline air quality monitoring stations covered in this report are summarised in Table 2.1 and shown in Appendix A1. Photographs of the monitoring equipment set up at baseline monitoring stations are given in Appendix A2.
Table 2.1: Baseline Air Quality Monitoring Stations
|
Monitoring Station |
Location |
Status |
|
DM-5 |
Lung Tseung Tau |
Existing Air Sensitive Receiver |
|
DM-6 |
Mok Ka |
Existing Air Sensitive Receiver |
2.3
Monitoring
Parameters, Frequency and Duration
Table 2.2 summarizes the monitoring parameters, frequency, duration and monitoring period of the baseline 1-hour TSP monitoring. The baseline air quality monitoring schedule is provided in Appendix A3.
Table 2.2: Air Quality Monitoring Parameters, Frequency and Period
|
Monitoring Station |
Parameter |
Frequency |
Duration |
Monitoring Period |
|
DM-5 |
1-hour Total Suspended Particulates (TSP) |
3 times per day |
14 consecutive days |
9 to 17 July 2021, 21 to 25 July 2021 |
|
DM-6 |
9 to 17 July 2021, 21 to 25 July 2021 |
Remark: Due to tropical cyclone, baseline air quality monitoring was suspended on 18, 19 and 20 July 2021 and resumed on 21 July 2021.
2.4
Monitoring Equipment
Portable direct reading dust meter was used to carry out the 1-hour TSP monitoring. Table 2.3 summarizes the equipment used in the baseline air quality monitoring. Copies of the calibration certificates for the portable dust meters are attached in Appendix A4.
Table 2.3: 1-hour TSP Monitoring Equipment
|
Monitoring Station |
Equipment |
Model |
|
DM-5 |
Portable direct reading dust meter |
SIBATA LD-3B (serial no. 276017) |
|
DM-6 |
Portable direct reading dust meter |
SIBATA LD-3B (serial no. 2Z6239) |
2.5
Monitoring
Methodology
1-hour TSP Monitoring
Field Monitoring
The measuring procedures of the 1-hour dust meter are in accordance with the Manufacturer’s Instruction Manual as follows:
● Turn the power on.
● Close the air collecting opening cover.
● Push the "TIME SETTING" switch to [BG].
● Push "START/STOP" switch to perform background measurement for 6 seconds.
● Turn the knob at SENSI ADJ position to insert the light scattering plate.
● Leave the equipment for 1 minute upon "SPAN CHECK" is indicated in the display.
● Push "START/STOP" switch to perform automatic sensitivity adjustment. This measurement takes 1 minute.
● Pull out the knob and return it to MEASURE position.
● Setting time period of 1 hour for the 1-hour TSP measurement.
● Push "START/STOP" to start the 1-hour TSP measurement.
● Regular checking of the time period setting to ensure monitoring time of 1 hour.
Maintenance and Calibration (QA/QC Procedure)
● The 1-hour dust meter would be checked at 3-month intervals and calibrated at 1-year intervals throughout all stages of the air quality monitoring.
● Calibration records for direct reading dust meters are given in Appendix A4.
2.6
Weather Data
Wind data collected from the Hong Kong Observatory’s (HKO) Chek Lap Kok (CLK) wind station was used for the air quality monitoring and is presented in Appendix A5. It is considered that the wind data obtained at the existing CLK wind station is representative of the Project area and could be used for undertaking the baseline and construction phase air quality monitoring programme for the Project.
The proposed use of the existing wind data collected from CLK wind station for wind data collection instead of setting up wind monitoring equipment near the monitoring stations was proposed by the ET Leader and agreed by IEC, in accordance with the requirements stated in Section 5.5 of the Updated EM&A Manual.
2.7
Results and Observations
The baseline air quality monitoring has been carried out at the two designated monitoring locations, namely DM-5 and DM-6, from 9 to 17 July 2021 and from 21 to 25 July 2021, for a total of 14 days. Due to tropical cyclone, baseline air quality monitoring was suspended on 18, 19 and 20 July 2021 and resumed on 21 July 2021.
The detection limit of the portable dust meter is 1 μg/m3. All portable dust meters were calibrated before conducting baseline air quality monitoring as quality assurance measure. The digital dust meters used produced a correlation coefficient of 0.9963 and 0.9954, which are higher than the acceptable value of 0.8. Calibration certificates of the portable dust meters are provided in Appendix A4.
The weather was generally sunny or cloudy during the baseline monitoring period. No major events were identified which may have influenced or affected the results of baseline monitoring. The detailed 1-hour TSP monitoring results are summarised in Table 2.4. Graphical plots of the monitoring results are shown in Appendix A6.
Table 2.4: Summary of Baseline 1-hour TSP Monitoring Results
|
Monitoring Station |
Average 1-hour TSP (μg/m3) |
1-hour TSP Range (μg/m3) |
|
DM-5 |
24 |
10 – 60 |
|
DM-6 |
16 |
6 – 30 |
2.8
Action and Limit Levels
The Action and Limit Levels for 1-hour TSP have been set in accordance with the derivation criteria specified in the Updated EM&A Manual and are reproduced in Table 2.5.
Table 2.5: Derivation of Action and Limit Levels for Air Quality
|
Parameter |
Action Level (μg/m3) |
Limit Level (μg/m3) |
|
1-hour TSP Level |
● For baseline level £ 384 μg/m3, Action level = (Baseline level * 1.3 + Limit level)/2; ● For baseline level > 384 μg/m3, Action level = Limit level |
500 |
Following the abovementioned criteria, the Action and Limit Levels of 1-hour TSP for the monitoring stations were derived and are presented in Table 2.6.
Table 2.6: Action and Limit Levels for 1-hour TSP
|
Monitoring Station |
Action Level (μg/m3) |
Limit Level (μg/m3) |
|
DM-5 |
266 |
500 |
|
DM-6 |
260 |
500 |
2.9
Event and Action
Plan
Should non-compliance of the air quality criteria occur, actions in accordance with the Event and Action Plan in Table 2.7 and Table 2.8 shall be carried out.
Table 2.7: Event and Action Plan for Construction Air Quality (Action Level)
|
Event |
Action |
|||
|
ET |
IEC |
ER |
Contractor |
|
|
Action Level |
|
|
|
|
|
Exceedance for one sample |
1. Identify source, investigate the causes of exceedance and propose remedial measures; 2. Inform IEC and ER; 3. Repeat measurement to confirm finding; 4. Increase monitoring frequency to daily. |
1. Check monitoring data submitted by ET; 2. Check Contractor’s working method. |
1. Notify Contractor. |
1. Rectify any unacceptable practice; 2. Amend working methods if appropriate. |
|
Exceedance for two or more consecutive samples |
1. Identify source; 2. Inform IEC and ER; 3. Advise the ER on the effectiveness of the proposed remedial measures; 4. Repeat measurements to confirm findings; 5. Increase monitoring frequency to daily; 6. Discuss with IEC and Contractor on remedial actions required; 7. If exceedance continues, arrange meeting with IEC and ER; 8. If exceedance stops, cease additional monitoring. |
1. Check monitoring data submitted by ET; 2. Check Contractor’s working method; 3. Discuss with ET and Contractor on possible remedial measures; 4. Advise the ET on the effectiveness of the proposed remedial measures; 5. Supervise Implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. Ensure remedial measures properly implemented. |
1. Submit proposals for remedial to ER within 3 working days of notification; 2. Implement the agreed proposals; 3. Amend proposal if appropriate. |
Table 2.8: Event and Action Plan for Construction Air Quality (Limit Level)
|
Event |
Action |
|||
|
ET |
IEC |
ER |
Contractor |
|
|
Limit Level |
|
|
|
|
|
Exceedance for one sample |
1. Identify source, investigate the causes of exceedance and propose remedial measures; 2. Inform ER, Contractor and EPD; 3. Repeat measurement to confirm finding; 4. Increase monitoring frequency to daily; 5. Assess effectiveness of Contractor’s remedial actions and keep IEC, EPD and ER informed of the results. |
1. Check monitoring data submitted by ET; 2. Check Contractor’s working method; 3. Discuss with ET and Contractor on possible remedial measures; 4. Advise the ER on the effectiveness of the proposed remedial measures; 5. Supervise implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. Ensure remedial measures properly implemented.. |
1. Take immediate action to avoid further exceedance; 2. Submit proposals for remedial actions to IEC within 3 working days of notification; 3. Implement the agreed proposals; 4. Amend proposal if appropriate. |
|
Exceedance for two or more consecutive samples |
1. Notify IEC, ER, Contractor and EPD; 2. Identify source; 3. Repeat measurement to confirm findings; 4. Increase monitoring frequency to daily; 5. Carry out analysis of Contractor’s working procedures to determine possible mitigation to be implemented; 6. Arrange meeting with IEC and ER to discuss the remedial actions to be taken; 7. Assess effectiveness of Contractor’s remedial actions and keep IEC, EPD and ER informed of the results; 8. If exceedance stops, cease additional monitoring. |
1. Discuss amongst ER, ET, and Contractor on the potential remedial actions; 2. Review Contractor’s remedial actions whenever necessary to assure their effectiveness and advise the ER accordingly; 3. Supervise the implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. In consultation with the IEC, agree with the Contractor on the remedial measures to be implemented; 4. Ensure remedial measures properly implemented; 5. If exceedance continues, consider what portion of the work is responsible and instruct the Contractor to stop that portion of work until the exceedance is abated. |
1. Take immediate action to avoid further exceedance; 2. Submit proposals for remedial actions to IEC within 3 working days of notification; 3. Implement the agreed proposals; 4. Resubmit proposals if problem still not under control; 5. Stop the relevant portion of works as determined by the ER until the exceedance is abated. |
3
Noise
3.1
Monitoring Requirement
According to the requirements in the Updated EM&A Manual, baseline noise monitoring shall be carried out prior to the commencement of the construction works. Continuous baseline noise monitoring for the A-weighted levels Leq, L10 and L90 shall be carried out daily for at least two weeks in a sample period interval of: 30 minutes between 0700 and 1900 on normal weekdays; and 5 minutes between 1900 and 0700 daily, and between 0700 and 1900 on Sundays/public holidays. Further details of the baseline noise monitoring are presented in the following sections.
3.2
Monitoring Locations
According to the Updated EM&A Manual, a total of nine noise monitoring stations are identified for the impact monitoring locations. Of these nine noise monitoring stations, five are located in the possible development area (PDA) at Tung Chung West and are covered by this report. Locations of the noise monitoring stations in the Updated EM&A Manual and this report are listed in Table 3.1 and shown in Appendix B1. Photographs of the monitoring equipment set up at baseline monitoring stations are given in Appendix B2.
Table 3.1: Baseline Noise Monitoring Stations
|
Monitoring Station |
Location |
Type of Measurement |
|
NMS-CA-5 |
Village house in Ma Wan Chung (G/F) |
Free field^ |
|
NMS-CA-6 |
Village house in Shek Mun Kap (G/F) |
Free field^ |
|
NMS-CA-7 |
YMCA of Hong Kong Christian College (Roof Floor) |
Façade |
|
NMS-CA-8# |
Caritas Charles Vath College (Roof Floor) |
Façade |
|
NMS-CA-9#,* |
Hong Chi Shiu Pong Morninghope School (Roof Floor) |
Façade |
Remark: # Prior to commencement of baseline monitoring, both school sites containing NMS-CA-8 and NMA-CA-9 were jointly visited by ET and IEC. It was confirmed that both original locations proposed in the Updated EM&A Manual were found to be too close to noise-emitting operating plant on each school roof floor, such as air-conditioner vents. These were relocated slightly to optimum locations on the same floors away from these infrastructures and duly presented in the "Baseline Monitoring Proposal for Construction Phase (Air Quality and Noise)", which was endorsed by IEC.
* NMS-CA-9, which was described as "possible school development near Tung Chung Area 39" in the Updated EM&A Manual, was subsequently confirmed as "Hong Chi Shiu Pong Morninghope School" prior to commencement of baseline monitoring.
^ For Free Field measurement, +3dB(A) should be added to the measured results.
3.3
Monitoring Parameters, Frequency and Duration
Table 3.2 summarizes the monitoring parameters, frequency, duration and periods of the baseline noise monitoring. The baseline noise monitoring schedule is provided in Appendix B3.
Table 3.2: Noise Monitoring Parameters, Frequency and Period
|
Monitoring Station |
Parameter |
Frequency |
Duration |
Monitoring Periods |
|
NMS-CA-5 |
Leq(5 mins), L10(5 mins), L90(5 mins) |
Daily |
14 days |
10 to 17 July 2021, 20 to 27 July 2021 |
|
NMS-CA-6 |
10 to 17 July 2021, 20 to 27 July 2021 |
|||
|
NMS-CA-7 |
16 to 18 August 2021, 19 to 31 August 2021 |
|||
|
NMS-CA-8 |
9 to 17 July 2021, 20 to 26 July 2021 |
|||
|
NMS-CA-9 |
9 to 17 July 2021, 20 to 26 July 2021 |
Remark: Due to tropical cyclone, baseline noise monitoring at NMS-CA-5, NMS-CA-6, NMS-CA-8 and NMS-CA-9 was suspended on 17 July 2021 at 19:00 and resumed on 20 July 2021 at 23:00. Also, due to rainstorm, baseline noise monitoring at NMS-CA-7 was suspended on 18 August 2021 at 23:00 and resumed on 19 August 2021 at 23:00.
3.4
Monitoring Equipment
Integrating Sound Level Meters were used to conduct baseline noise monitoring. They were the Type 1 sound level meter capable of giving a continuous readout of the noise level readings including equivalent continuous sound pressure level (LAeq) and percentile sound pressure level (Lx). They complied with International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1). Table 3.3 summarizes the equipment used in the baseline noise monitoring. Copies of the calibration certificates for the sound level meters and acoustical calibrator are attached in Appendix B4.
Table 3.3: Noise Monitoring Equipment
|
Monitoring Station |
Equipment & Model |
|
|
|
Integrating Sound Level Meter |
Acoustical Calibrator |
|
NMS-CA-5 |
Rion NL-52 (serial no. 00175561) |
Larson Davis CAL200 (serial no. 16172) |
|
NMS-CA-6 |
Rion NL-52 (serial no. 00643039) |
Larson Davis CAL200 (serial no. 16172) |
|
NMS-CA-7 |
Rion NL-52 (serial no. 00131628) |
Larson Davis CAL200 (serial no. 10227) |
|
NMS-CA-8 |
Rion NL-52 (serial no. 00710259) |
Larson Davis CAL200 (serial no. 16172) |
|
NMS-CA-9 |
Rion NL-52 (serial no. 00131628) |
Larson Davis CAL200 (serial no. 16172) |
3.5
Monitoring Methodology
3.5.1
Monitoring Procedure
The noise monitoring was undertaken using the following procedure:
a. The sound level meter was set at least 1.2 m above the ground for free-field measurements at monitoring stations NMS-CA-5 and NMS-CA-6. A correction of +3 dB(A) has been made for the free field measurements.
b. Façade measurements were made at the monitoring stations NMS-CA-7, NMS-CA-8 and NMS-CA-9.
c. The battery condition was checked to ensure the correct functioning of the meters.
d. Parameters such as frequency weighting, the time weighting and the measurement time were set as follows:
i. frequency weighting: A
ii. time weighting: Fast
iii. time measurement: 5-minutes for Leq, L10 and L90, with the calculation of the Leq(30mins) noise levels for each 30-minute interval during the non-restricted hours (i.e. 0700 – 1900 hours on normal weekdays) calculated after the measurements by logarithmic average of six Leq(5min) data.
e. Prior to and after each noise measurement, the meter was calibrated using the acoustic calibrator for 94dB(A) at 1000 Hz. If the difference in the calibration level before and after measurement was more than 1 dB(A), the measurement would be considered invalid and repeat of noise measurement would be required after re-calibration or repair of the equipment.
f. During the monitoring period, the Leq, L10 and L90 were recorded. In addition, site conditions and noise sources were recorded when the equipment were checked and inspected every 2-3 days.
g. All the monitoring data stored in the sound level meter system were downloaded through computer software, and all the data was checked and reviewed on computer.
3.5.2
Maintenance and Calibration
The maintenance and calibration procedures are summarised below:
a. The microphone head of the sound level meter was cleaned with soft cloth at regular intervals.
b. The meter and calibrator were sent to the supplier or HOKLAS laboratory to check and calibrate at yearly intervals.
c. Calibration certificates of the sound level meters and acoustic calibrator are provided in Appendix B4.
3.6
Results and
Observations
The noise monitoring results are summarised in Table 3.4 to Table 3.6. Detailed noise monitoring results are presented in Appendix B5. In accordance with Section 6.5.1 of the Updated EM&A Manual, a correction of +3 dB(A) was made to the free field measurements at NMS-CA-5 and NMS-CA-6.
Table 3.4: Summary of Baseline Noise Monitoring Results – Normal Weekday Daytime (0700-1900 hrs)
|
Time Period & Monitoring Station |
Leq (30 mins), dB(A) |
|
|
Normal Weekday Daytime (0700-1900 hrs) |
Mean |
Range |
|
NMS-CA-5 |
57.3^ |
48.9 – 67.8^ |
|
NMS-CA-6 |
58.7^ |
50.3 – 75.4^ |
|
NMS-CA-7 |
55.0 |
49.5 – 66.2 |
|
NMS-CA-8 |
56.1 |
51.3 – 65.7 |
|
NMS-CA-9 |
60.4 |
56.6 – 68.4 |
Remark: ^ Includes +3dB(A) correction for Free Field measurement.
Table 3.5: Summary of Baseline Noise Monitoring Results – Evening on Normal Weekday (1900-2300 hrs) and Sunday/Public Holiday (0700-2300 hrs)
|
Time Period & Monitoring Station |
Leq (5 mins), dB(A) |
|
|
Evening on Normal Weekday (1900-2300 hrs) and Sunday/Public Holiday (0700-2300 hrs) |
Mean |
Range |
|
NMS-CA-5 |
53.0^ |
45.5 – 70.2^ |
|
NMS-CA-6 |
53.2^ |
46.2 – 74.0^ |
|
NMS-CA-7 |
52.3 |
44.7 – 68.7 |
|
NMS-CA-8 |
52.9 |
47.1 – 69.6 |
|
NMS-CA-9 |
58.5 |
50.7 – 67.5 |
Remark: ^ Includes +3dB(A) correction for Free Field measurement.
Table 3.6: Summary of Baseline Noise Monitoring Results – Night-time (2300-0700 hrs)
|
Time Period & Monitoring Station |
Leq (5 mins), dB(A) |
|
|
Night-time (2300-0700 hrs) |
Mean |
Range |
|
NMS-CA-5 |
50.8^ |
45.6 – 87.2^ |
|
NMS-CA-6 |
49.8^ |
45.0 – 71.7^ |
|
NMS-CA-7 |
49.6 |
42.6 – 58.6 |
|
NMS-CA-8 |
50.9 |
45.7 – 68.4 |
|
NMS-CA-9 |
53.4 |
47.2 – 71.6 |
Remark: ^ Includes +3dB(A) correction for Free Field measurement.
3.7
Action and Limit Levels
The Action Levels and Limit Levels for construction noise impact monitoring have been defined in accordance with the Updated EM&A Manual and are tabulated in Table 3.7.
Table 3.7: Action and Limit Levels for Construction Noise
|
Monitoring Station |
Time Period |
Action Level |
Limit Level, Leq (30 mins), dB(A) |
|
NMS-CA-5 NMS-CA-6 |
0700-1900 hrs on normal weekdays# |
When one documented complaint is received |
75 |
|
NMS-CA-7* NMS-CA-8* NMS-CA-9* |
70 (65 during school examination periods) |
Note: # 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.
* Denotes school / educational institution.
3.8
Event and Action Plan
Should non-compliance of the noise criteria occur, actions in accordance with the Event and Action Plan in Table 3.8 shall be carried out.
Table 3.8: Event and Action Plan for Construction Noise
|
Event |
Action |
|||
|
ET |
IEC |
ER |
Contractor |
|
|
Action Level Exceedance |
1. Notify IEC, ER and Contractor; 2. Carry out investigation; 3. Report the results of investigation to the IEC, ER and Contractor; 4. Discuss with the Contractor and formulate remedial measures; 5. Increase monitoring frequency to check mitigation effectiveness. |
1. Review the analysed results submitted by the ET; 2. Review the proposed remedial measures by the Contractor and advise the ER accordingly; 3. Supervise the implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. Require Contractor to propose remedial measures for the analysed noise problem; 4. Ensure remedial measures are properly implemented |
1. Submit noise mitigation proposals to IEC and ER; 2. Implement noise mitigation proposals. |
|
Limit Level Exceedance |
1. Identify source; 2. Inform IEC, ER, EPD and Contractor; 3. Repeat measurements to confirm findings; 4. Increase monitoring frequency; 5. Carry out analysis of Contractor’s working procedures to determine possible mitigation to be implemented; 6. Inform IEC, ER and EPD the causes and actions taken for the exceedances; 7. Assess effectiveness of Contractor’s remedial actions and keep IEC, EPD and ER informed of the results; 8. If exceedance stops, cease additional monitoring. |
1. Discuss amongst ER, ET, and Contractor on the potential remedial actions; 2. Review Contractors remedial actions whenever necessary to assure their effectiveness and advise the ER accordingly; 3. Supervise the implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. Require Contractor to propose remedial measures for the analysed noise problem; 4. Ensure remedial measures properly implemented; 5. If exceedance continues, consider what portion of the work is responsible and instruct the Contractor to stop that portion of work until the exceedance is abated. |
1. Take immediate action to avoid further exceedance; 2. Submit proposals for remedial actions to IEC within 3 working days of notification; 3. Implement the agreed proposals; 4. Resubmit proposals if problem still not under control; 5. Stop the relevant portion of works as determined by the ER until the exceedance is abated. |
4
Water Quality
4.1
Monitoring Requirement
In accordance with the Updated EM&A Manual, the baseline water quality monitoring shall be carried out 3 days per week for at least 4 weeks prior to the commencement of construction works at TCW. The measurements shall be taken at all designated monitoring stations at TCW in accordance with the requirements in the approved Baseline Monitoring Proposal for Water Quality. Further details of the baseline water quality monitoring under this Project are presented in the following sections.
4.2
Monitoring
Locations
According to the Updated EM&A Manual, five water quality monitoring stations are identified and located in the possible development area (PDA) at Tung Chung West and are covered by this report. All monitoring locations were checked on site to verify their suitability and accessibility.
Following a review of the monitoring programme including monitoring locations with green groups in June 2021, two new monitoring stations were added (TCW-WQM6 and TCW-WQM7). Also, the original location of TCW-WQM3 was replaced with revised location TCW-WQM3A located upstream of the River Park since the original location will be directly modified and inaccessible during construction works. Furthermore, original location TCW-WQM5 was replaced with revised location TCW-WQM5A (at the nearest safe and practical location) since the original location is presently inaccessible for the purposes of baseline monitoring.
The updated list of locations of the water quality monitoring stations in the approved Baseline Monitoring Proposal for Construction Phase Water Quality are listed in Table 4.1 and shown in Appendix C1. Photographs of the monitoring conducted at the baseline monitoring stations are given in Appendix C2.
Table 4.1: Baseline Water Quality Monitoring Stations
|
Monitoring Station |
Description |
Location |
|
|
|
Easting |
Northing |
|
|
TCW-WQM1 |
Downstream of Tung Chung Stream |
810784 |
815710 |
|
Tung Chung Stream (West) |
|||
|
TCW-WQM2 |
Middle of Tung Chung Stream (West) |
810701 |
815015 |
|
TCW-WQM4 |
Upstream of Tung Chung Stream (West) |
810641 |
814405 |
|
TCW-WQM6(1) |
Downstream of Tung Chung Stream (West) |
810814 |
815385 |
|
Tung Chung Stream (East) |
|||
|
TCW-WQM3A(2) |
Middle of Tung Chung Stream (East) [aka Upstream of River Park] |
811080 |
814965 |
|
TCW-WQM5A(3) |
Upstream of Tung Chung Stream (East) |
811194 811138 |
814368 814498 |
|
TCW-WQM7(1) |
Downstream of Tung Chung Stream (East) [aka Downstream of River Park] |
810862 |
815400 |
Notes:
(1) TCW-WQM6 and TCW-WQM7 are additional monitoring stations which can monitor the water quality impact associated with construction activities along the Tung Chung Stream (West) and Tung Chung Stream (East) respectively.
(2) TCW-WQM3A is the proposed relocated TCW-WQM3, which will be upstream of the River Park where there are no direct works on Tung Chung Stream (East). The original TCW-WQM3 location lies within the construction works area for the future River Park, which will be directly modified and inaccessible during construction phase.
(3) The monitoring location of TCW-WQM5A will be bounded by the coordinates shown, with the exact location depending on the nearest safe accessible and practical location to the original TCW-WQM5.
4.3
Monitoring Parameters, Frequency and Schedule
Table 4.2 summarises the monitoring parameters, monitoring period and frequencies of the water quality monitoring. The baseline water quality monitoring schedule is provided in Appendix C3.
Table 4.2: Water Quality Monitoring Parameters and Frequency
|
Monitoring Station |
Parameters (Units) |
Frequency and Replication |
|
TCW-WQM1, TCW-WQM2, TCW-WQM3A, TCW-WQM4, TCW-WQM5A, TCW-WQM6 TCW-WQM7 |
· Dissolved Oxygen (DO) (mg/L and % saturation) · Temperature (°C) · Turbidity (NTU) · Salinity (ppt) · pH · Suspended Solids (SS) (mg/L) · Conductivity(1) (µS/cm) |
Baseline monitoring: 3 days per week, for 4 weeks prior to the commencement of construction work. Two (2) replicate in-situ measurements and water samples. |
Remark: Water depth measurement is not applicable due to very shallow depth of the monitoring locations.
Note:
(1) Conductivity is an additional reference monitoring parameter adopted at the request of green groups during a review of the baseline monitoring programme in June 2021 as referred in Section 4.2. It is not compulsory as prescribed in the Updated EM&A Manual.
In addition to the parameters presented in Table 4.2, other relevant data were also recorded, including monitoring location, time, approximate water depth (by visual observation), tidal condition (if applicable), weather conditions and any special phenomena or work underway at the Project site.
4.4
Monitoring Methodology
Table 4.3 summarizes the equipment used in the baseline water quality monitoring works. All the monitoring equipment complied with the requirements set out in the Updated EM&A Manual. Copies of the calibration certificates are attached in Appendix C4.
Table 4.3: Water Quality Monitoring Equipment
|
Equipment |
Brand and Model |
Quantity |
|
Multifunctional Meter (in-situ measurement of DO, pH, temperature, salinity, turbidity and conductivity) |
Horiba U-53 (serial nos. KP23RR5M & LUAVCDWU) |
2 |
4.4.1
Operating/Analytical Procedures
At each sampling location, two consecutive measurements of DO level, DO Saturation, Temperature, Turbidity, Salinity and pH were taken. Where the difference in the value between the first and second readings of each set was more than 25% of the value of the first readings, the reading was discarded and further readings were taken. Two samples were collected at each individual monitoring location for laboratory analysis of SS content. Following collection, water samples for laboratory analysis were stored in high density polythene bottles (1L) with no preservatives added, packed in ice (cooled to 4°C without being frozen) and kept in dark during both on-site temporary storage and shipment to the testing laboratory. The samples were delivered to the laboratory as soon as possible and the laboratory determination works started within 24 hours after collection of the water samples. Sufficient volume of samples was collected to achieve the reporting limit.
4.4.2
Laboratory Analytical Methods
The testing of SS 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 testing method and reporting limit are provided in Table 4.4.
Table 4.4: Methods for Laboratory Analysis for Water Samples
|
Parameter |
Analytical Method |
Reporting Limit |
|
Suspended Solids (SS) |
APHA 17e 2540D |
0.5 mg/L |
4.5
Quality Assurance (QA) / Quality Control (QC) Requirements
4.5.1
Calibration of In-situ Instruments
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 three-monthly intervals throughout all stages of the water quality monitoring programme. Responses of sensors and electrodes were checked with certified standard solutions before each daily use. Wet bulb calibration for a DO meter was carried out before measurement at each monitoring event.
For the on-site calibration of field equipment (Multi-parameter Water Quality System), the BS 1427:2009, "Guide to on-site test methods for the analysis of waters" was observed.
Sufficient stocks of spare parts were maintained for replacements when necessary. Backup monitoring equipment was also made available so that monitoring can proceed uninterrupted even when some equipment was under maintenance, calibration, etc.
4.5.2
Sampling
Management and Supervision
All sampling bottles were labelled with the sample ID (such as 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.
4.5.3
Quality Control Measures for Sample Testing
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 set of quality control (QC) samples (including method QC and sample duplicate).
4.6
Baseline Monitoring Results
The 4-week baseline water quality monitoring was conducted at the six baseline monitoring stations within Tung Chung River (TCW-WQM2, TCW-WQM3A, TCW-WQM4, TCW-WQM5A, TCW-WQM6 and TCW-WQM7), while a 4-week baseline plus supplementary 4-weeks (total 8-weeks) baseline water quality monitoring was conducted at TCW-WQM1 located within Tung Chung Bay (refer to Section 4.7.4). The monitoring results at each monitoring station are shown in Appendix C5.
Graphical presentation of baseline water quality at each monitoring station is presented in Appendix C6 and grouped into the following for ease of reference:
● TCW-WQM2, TCW-WQM4 and TCW-WQM6 for the stream located in the west of Tung Chung Valley (i.e. Tung Chung Stream (West) – see Figures C6-7 to C6-12);
● TCW-WQM3A, TCW-WQM5A and TCW-WQM7 for the stream located in the east of Tung Chung Valley (i.e. Tung Chung Stream (East) – see Figures C6-13 to C6-18);
● TCW-WQM1 (i.e. downstream of both abovementioned West and East streams – see Figures C6-1 to C6-6).
During the baseline monitoring period, no construction works were observed in the vicinity of all monitoring stations. The baseline monitoring results are thus considered representative of the ambient water quality of the Project area during the season.
4.7
Results Discussion
The results for DO, Turbidity and SS were analysed to inform the approach for deriving Action and Limit Levels. As Tung Chung Stream (West) and Tung Chung Stream (East) are not directly hydraulically connected until the point downstream of TCW-WQM6 and TCW-WQM7 (where they converge before flowing out to Tung Chung Bay), it is sensible to consider the water quality results under the following groups:
● Tung Chung Stream (West) stations (i.e. TCW-WQM2, TCW-WQM4 and TCW-WQM6)
● Tung Chung Stream (East) stations (i.e. TCW-WQM3A, TCW-WQM5A and TCW-WQM7)
● Tung Chung Bay station (i.e. TCW-WQM1)
4.7.1
Tung Chung Stream (West) Stations
DO results along this stream ranges from 1.8 mg/L to 5.9 mg/L, with a clear increasing trend in DO concentrations further downstream. The particularly low DO results at upstream (TCW-WQM4 with results ranging from 1.8 mg/L to 3.4 mg/L) appears to be somewhat unusual but may be attributed to an area of relatively stagnant waters which can easily deplete DO.
Results for Turbidity and SS both show very low values except for one monitoring day (1 Sep) which was associated with a rainstorm event. Trend analysis between the control station (TCW-WQM4) and impact stations (TCW-WQM2 and TCW-WQM6) shows that Turbidity values at impact stations are ‘best fit’ at 1.8188x (~182%) that of the same-day control (see Appendix C7). The generally low absolute values of Turbidity recorded during the baseline monitoring is more likely to give rise to higher percentage differences between the upstream and the mid to downstream sections of Tung Chung Stream (West).
For SS which has very low absolute values (between 0.5 mg/L to 2.2 mg/L excluding the rainstorm event on 1 Sep), the trend shows an even greater difference between control and impact stations (best fit line at 2.4045x or ~240%). This is reflected in the tabulated percentage difference between control and impact stations (see Appendix C7), whereby 18 out of the 24 datasets show a difference greater than the standard 120% of same-day control adopted as Action Level for construction phase impact water quality monitoring.
4.7.2
Tung Chung Stream (East) Stations
DO results along this stream ranges from 3.9 mg/L to 6.5 mg/L, with values typically slightly higher upstream than downstream.
Results for Turbidity and SS show similar low values as those at Tung Chung Stream (West), except for one monitoring day (1 Sep) which was associated with a rainstorm event. Trend analysis between the control station (TCW-WQM5A) and impact stations (TCW-WQM3A and TCW-WQM7) shows that Turbidity values at impact stations are ‘best fit’ at 1.508x (~151%) that of the same-day control (see Appendix C7). Again, the generally low absolute values of Turbidity recorded during the baseline monitoring is more likely to give rise to higher percentage differences between the upstream and the mid to downstream sections of Tung Chung Stream (East).
For SS which has similarly low absolute values (between 0.6 mg/L to 6.8 mg/L excluding the rainstorm event on 1 Sep), the trend shows an even greater difference between control and impact stations (best fit line at 2.2309x or ~223%). This is reflected in the tabulated percentage difference between control and impact stations (see Appendix C7), whereby 23 out of the 24 datasets show a difference greater than the standard 120% of same-day control adopted as Action Level for construction phase impact water quality monitoring.
4.7.3
Tung Chung Bay Station
DO results at TCW-WQM1 varies from 1.7 mg/L to 8.0 mg/L. Data from the total 8-week monitoring period at this station exhibits a broader range compared to the DO results from Tung Chung Stream (West and East) stations (with 4-week concurrent baseline period) and does not exhibit a notable pattern compared to the other stations, suggesting that the DO at TCW-WQM1 is not entirely dependent on the DO content of flows from Tung Chung Streams.
Turbidity values at this station are notably higher and SS values at this station are slightly higher than at the Tung Chung Stream stations for most of the time, ranging from 3.8 NTU to 38.3 NTU for Turbidity, and 2.1 mg/L to 10.4 mg/L for SS respectively. TCW-WQM1 is affected by both Tung Chung Stream (West and East) stations as well as tidal effects, which may complicate the patterns of Turbidity and SS observed at this station.
4.7.4
Implications on Action and Limit Levels
DO
Action and Limit Levels for DO as specified in the Updated EM&A Manual are based solely on the baseline dataset obtained during the 4-week baseline monitoring period or the WQOs. As identified in Section 4.7.1, the DO results at TCW-WQM4 are unusually low, and inclusion of these results to derive the 5 percentile and 1 percentile Action and Limit Levels would create very low ‘permissible’ DO levels applied at the midstream and downstream stations (TCW-WQM2 and TCW-WQM6) which is not reflective of the baseline DO levels observed at these locations further downstream. Therefore, it is considered more prudent to exclude the results from TCW-WQM4 in determining the Action and Limit Levels for DO at Tung Chung Stream (West). In addition, while the use of same-day controls is not specified for DO, reference to the DO levels at the upstream control stations are nevertheless recommended during exceedance investigations for DO to facilitate consideration of both natural and anthropogenic factors that may contribute to DO depletion at the impact stations.
Turbidity and SS
As shown in Appendix C7, both TCW-WQM4 and TCW-WQM5A (control stations) exhibit a natural difference in Turbidity and SS to the downstream sections of Tung Chung Stream (West) and Tung Chung Stream (East) that already exceeds the standard 120% Action Level and 130% Limit Level threshold for a significant amount of time (for Turbidity) and a vast majority of the time (for SS). What this means is that under normal conditions, the trigger for Action and Limit Level exceedance would rely heavily and almost exclusively on the baseline-derived 95 and 99 percentile thresholds to screen out natural variations. The same-day control threshold may only be useful for dealing with atypical conditions whereby the control station already shows very high Turbidity / SS (e.g. due to illegal dumping or landslip events upstream of the Project).
Given the heavy reliance of the Action and Limit Levels on the baseline-derived 95 percentile and 99 percentile values, the baseline data should be able to represent the natural variations in water quality that are highly seasonal and weather dependent. However, the data collected during that baseline period appeared to be inadequate to cover such natural variations at Tung Chung River. This is evident from the baseline data, which showed that a single rainstorm event (on 1 Sep 2021) can generate huge disparities between control and impact station results. The 4-week baseline period was only able to capture one such rainstorm event, which reduces the reliability of the baseline-derived 95 and 99 percentile thresholds to adequately factor in such weather-related natural variations. Therefore, it would be prudent to incorporate additional baseline data to make the baseline-derived 95 and 99 percentiles more robust.
Existing baseline data at Tung Chung River is available from EPD’s routine river water quality monitoring programme, which includes two monitoring stations at Tung Chung River (TC1 at Tung Chung Stream West and TC2 at Tung Chung Stream East). The dataset from EPD is considered to be highly robust as it has been conducted monthly (for most years) since 2000, and directly relevant to this Project as the monitoring locations for TC1 and TC2 are within the Project area. Recognising that the construction programme for this Project will span approx. 10 years, a baseline dataset covering an equivalent timespan would be best suited to providing the appropriate level of robustness needed to represent the baseline for the next 10 years. Hence it is proposed to incorporate EPD’s latest 10-year routine river water quality monitoring data along with the baseline data obtained by this Project to generate the baseline-derived 95 percentile and 99 percentile Action and Limit Levels for Tung Chung Stream (West) and Tung Chung Stream (East) respectively.
TCW-WQM1
Due to the tidal nature of TCW-WQM1, the control stations TCW-WQM4 and TCW-WQM5A cannot adequately represent the ‘upstream’ conditions for benchmarking against same day results. There is also no EPD routine marine water quality monitoring station that can represent the area of Tung Chung Bay for supplementing the baseline data at TCW-WQM1. Given these circumstances, the Action and Limit Levels at TCW-WQM1 can only be based on its baseline dataset. In the absence of EPD routine marine water quality monitoring station data at Tung Chung Bay, a supplementary 4-week baseline monitoring was carried out at TCW-WQM1 in October to November 2021 to extend the baseline monitoring dataset for deriving the Action and Limit Levels at TCW-WQM1. The Action and Limit Levels at TCW-WQM1 are thus based on a total of 8-weeks baseline dataset.
Recognising that the construction programme for this Project will span approx. 10 years, the baseline conditions will be reviewed regularly and updated as appropriate, to demonstrate the continued suitability of the impact and control monitoring.
4.8
Action and Limit
Levels
The criteria for Action and Limit Levels for DO, Turbidity and SS, taking into account the update proposed in Section 4.7.4, are summarized in Table 4.5.
Table 4.5: Updated Criteria for Action and Limit Levels for Impact Water Quality Monitoring
|
Parameters |
Action Level |
Limit Level |
|
Tung Chung Stream (West) |
||
|
DO in mg/L |
5 percentile of baseline data |
1 percentile of baseline data |
|
SS in mg/L |
95 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC1) or 120% of upstream control station at the same tide of the same day, whichever is higher |
99 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC1) or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Turbidity in NTU |
95 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC1) or 120% of upstream control station at the same tide of the same day, whichever is higher |
99 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC1) or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Tung Chung Stream (East) |
||
|
DO in mg/L |
5 percentile of baseline data |
1 percentile of baseline data |
|
SS in mg/L |
95 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC2) or 120% of upstream control station at the same tide of the same day, whichever is higher |
99 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC2) or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Turbidity in NTU |
95 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC2) or 120% of upstream control station at the same tide of the same day, whichever is higher |
99 percentile of baseline data + EPD latest 10-year data for Tung Chung River (TC2) or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
TCW-WQM1 |
|
|
|
DO in mg/L |
5 percentile of baseline data |
1 percentile of baseline data |
|
SS in mg/L |
95 percentile of baseline data |
99 percentile of baseline data |
|
Turbidity in NTU |
95 percentile of baseline data |
99 percentile of baseline data |
Notes:
(1) For DO, non-compliance occurs when monitoring results is lower than the limits.
(2) For SS and Turbidity, non-compliance occurs when monitoring results is larger than the limits.
(3) Water depth-separated measurements (such as DO surface and middle and DO bottom) is not applicable due to very shallow depth of the monitoring locations in Tung Chung West whereby only one sampling depth applies.
(4) EPD’s latest 10-year data for Tung Chung River (2011 – 2020) obtained from EPD’s website https://www.epd.gov.hk/epd/epic/english/data_river_monitoring.html.
The calculated Action and Limit levels for Tung Chung Stream (West), Tung Chung Stream (East) and TCW-WQM1 are shown in Table 4.6. Note that as recommended in Section 4.7.4, the DO results from TCW-WQM4 are excluded in the determination of the Action and Limit Levels for DO at Tung Chung Stream (West).
Table 4.6: Calculated Action and Limit Levels for Impact Water Quality Monitoring
|
Parameters |
Action Level |
Limit Level |
|
Tung Chung Stream (West) |
||
|
DO in mg/L |
3.4 mg/L |
3.3 mg/L |
|
SS in mg/L |
7.0 mg/L or 120% of upstream control station at the same tide of the same day, whichever is higher |
16.9 mg/L or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Turbidity in NTU |
6.7 NTU or 120% of upstream control station at the same tide of the same day, whichever is higher |
22.0 NTU or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Tung Chung Stream (East) |
||
|
DO in mg/L |
4.2 mg/L |
4.0 mg/L |
|
SS in mg/L |
7.2 mg/L or 120% of upstream control station at the same tide of the same day, whichever is higher |
9.7 mg/L or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Turbidity in NTU |
9.8 NTU or 120% of upstream control station at the same tide of the same day, whichever is higher |
22.5 NTU or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
TCW-WQM1 |
|
|
|
DO in mg/L |
2.2 mg/L |
1.8 mg/L |
|
SS in mg/L |
7.3 mg/L |
9.7 mg/L |
|
Turbidity in NTU |
24.7 NTU |
35.3 NTU |
Notes:
(1) For DO, non-compliance occurs when monitoring results is lower than the limits.
(2) For SS and Turbidity, non-compliance occurs when monitoring results is larger than the limits.
(3) Action and Limit Levels do not apply to TCW-WQM4 and TCW-WQM5A which are upstream control stations.
4.9
Event and Action
Plan
Should non-compliance of the water quality criteria occur, actions in accordance with the Event and Action Plan in the Table 4.7 below shall be carried out.
Table 4.7: Event and Action Plan for Construction Water Quality
|
Event |
Action |
|||
|
ET |
IEC |
ER |
Contractor |
|
|
Action Level Exceedance for one sampling day |
1. Inform IEC, Contractor and ER; 2. Check monitoring data, all plant, equipment and Contractor’s working methods; and 3. Discuss remedial measures with IEC and Contractor and ER. |
1. Discuss with ET, ER and Contractor on the implemented mitigation measures; 2. Review proposals on remedial measures submitted by Contractor and advise the ER accordingly; and 3. Review and advise the ET and ER on the effectiveness of the implemented mitigation measures. |
1. Discuss with IEC, ET and Contractor on the implemented mitigation measures; 2. Make agreement on the remedial measures to be implemented; 3. Supervise the implementation of agreed remedial measures. |
1. Identify source(s) of impact; 2. Inform the ER and confirm notification of the non-compliance in writing; 3. Rectify unacceptable practice; 4. Check all plant and equipment; 5. Consider changes of working methods; 6. Discuss with ER, ET and IEC and purpose remedial measures to IEC and ER; and 7. Implement the agreed mitigation measures. |
|
Action Level Exceedance for more than one consecutive sampling days |
1. Repeat in-situ measurement on next day of exceedance to confirm findings; 2. Inform IEC, contractor and ER; 3. Check monitoring data, all plant, equipment and Contractor’s working methods; 4. Discuss remedial measures with IEC, contractor and ER 5. Ensure remedial measures are implemented. |
1. Discuss with ET, Contractor and ER on the implemented mitigation measures; 2. Review the proposed remedial measures submitted by Contractor and advise the ER accordingly; and 3. Review and advise the ET and ER on the effectiveness of the implemented mitigation measures. |
1. Discuss with ET, IEC and Contractor on the proposed mitigation measures; 2. Make agreement on the remedial measures to be implemented ; and 3. Discuss with ET, IEC and Contractor on the effectiveness of the implemented remedial measures. |
1. Identify source(s) of impact; 2. Inform the ER and confirm notification of the non-compliance in writing; 3. Rectify unacceptable practice; 4. Check all plant and equipment and consider changes of working methods; 5. Discuss with ET, IEC and ER and submit proposal of remedial measures to ER and IEC within 3 working days of notification; and 6. Implement the agreed mitigation measures. |
|
Limit Level Exceedance for one sampling day |
1. Repeat in-situ measurement on next day of exceedance to confirm findings; 2. Inform IEC, contractor and ER; 3. Rectify unacceptable practice; 4. Check monitoring data, all plant, equipment and Contractor’s working methods; 5. Consider changes of working methods; 6. Discuss mitigation measures with IEC, ER and Contractor; and 7. Ensure the agreed remedial measures are implemented. |
1. Discuss with ET, Contractor and ER on the implemented mitigation measures; 2. Review the proposed remedial measures submitted by Contractor and advise the ER accordingly; and 3. Review and advise the ET and ER on the effectiveness of the implemented mitigation measures. |
1. Discuss with ET, IEC and Contractor on the implemented remedial measures; 2. Request Contractor to critically review the working methods; 3. Make agreement on the remedial measures to be implemented; and 4. Discuss with ET, IEC and Contractor on the effectiveness of the implemented remedial measures. |
1. Identify source(s) of impact; 2. Inform the ER and confirm notification of the non-compliance in writing; 3. Rectify unacceptable practice; 4. Check all plant and equipment and consider changes of working methods; 5. Discuss with ET, IEC and ER and submit proposal of additional mitigation measures to ER and IEC within 3 working days of notification; and 6. Implement the agreed remedial measures. |
|
Limit Level Exceedance for more than one consecutive sampling days |
1. Inform IEC, Contractor and ER; 2. Check monitoring data, all plant, equipment and Contractor’s working methods; 3. Discuss mitigation measures with IEC, ER and Contractor; and 4. Ensure mitigation measures are implemented; and 5. Increase the monitoring frequency to daily until no exceedance of Limit Level for two consecutive days. |
1. Discuss with ET, Contractor and ER on the implemented mitigation measures; 2. Review the proposed remedial measures submitted by Contractor and advise the ER accordingly; and 3. Review and advise the ET and ER on the effectiveness of the implemented mitigation measures. |
1. Discuss with ET, IEC and Contractor on the implemented remedial measures; 2. Request Contractor to critically review the working methods; 3. Make agreement on the remedial measures to be implemented; 4. Discuss with ET and IEC on the effectiveness of the implemented mitigation measures; and 5. Consider and instruct, if necessary, the Contractor to slow down or to stop all or part of the relevant site construction activities until no exceedance of Limit level. |
1. Identify source(s) of impact; 2. Inform the ER and confirm notification of the non-compliance in writing; 3. Rectify unacceptable practice; 4. Check all plant and equipment and consider changes of working methods; 5. Discuss with ET, IEC and ER and submit proposal of additional mitigation measures to ER and IEC within 3 working days of notification; and 6. Implement the agreed remedial measures. 7. As directed by the ER, to slow down or stop all or part of the relevant site construction activities until no exceedance of Limit level. |
5
Ecology
5.1
Background
As described in Section 9.5.1.5 of the Environmental Impact Assessment (EIA) Report for TCNTE (AEIAR-196/2016), in order to restore the ecological connection between the upstream and downstream of Tung Chung Stream, it is proposed to revitalise most part of its existing channelised section, and convert together with its natural section into amenity uses and for environmental enhancement, i.e. in a form as a River Park. This River Park would occupy an area of approximately 3.3ha along a total length of 775m and would aim to promote eco-education by setting up viewing decks / boardwalk, passive recreation zone for appreciation of natural environment. Besides, this Park would also help to prevent massive infrastructures within the Park to avoid impacts due to construction and human disturbance.
According to Section 11.4.5 of the Updated EM&A Manual (Revision 1) dated 15 May 2018 for EP No. EP-519/2016 TCNTE, a 12-month pre-construction baseline ecological monitoring of the Tung Chung River Park and Public Works (including road crossing, and attenuation and treatment pond) is required to be undertaken.
To match with the construction program next to the Eastern Tributary of Tung Chung Stream of TCW which was planned to be commenced in Q3/Q4 2021, CEDD has appointed the Environmental Team of Tung Chung New Town Extension (East) ("TCE ET") to prepare a Detailed Ecological and Water Quality Monitoring Plan ("Monitoring Plan") in early 2020. The Monitoring Plan was eventually agreed with EPD and AFCD in mid 2020, and the pre-construction baseline ecological monitoring was commenced in August 2020 accordingly by the TCE ET.
The 12-month pre-construction baseline ecological monitoring at the Eastern Tributary of Tung Chung Stream was completed in July 2021. The TCE ET has summarized all the baseline monitoring results in an Ecological and Water Quality Final Monitoring Report ("Monitoring Report") which was ready in August 2021 and passed to the TCW ET for the preparation of TCW Baseline Monitoring Report.
With the anticipated commencement of the construction programme next to the Western Tributary of Tung Chung Stream of TCW in Q4 of 2024, TCW ET prepared a Baseline Monitoring Proposal (Ecological and Water Quality Monitoring Plan – Western Tributary of Tung Chung Stream) ("Monitoring Proposal") in January 2023 which was agreed with EPD and AFCD in February 2023. The pre-construction baseline ecological monitoring at the Western Tributary of Tung Chung Stream was commenced in May 2023 and completed in March 2024.
As stated in Section 11.4.5 of the Updated EM&A Manual, Action and Limit Levels with reference to the baseline survey data, by considering the species (taxa diversity or abundance) and season, should be established for evaluating the ecological impact during the construction phase. When these limits are triggered, appropriate responses shall be made. The following section will present the analysis of data extracted from the Monitoring Report for the consideration of establishing the Action and Limit Levels and an Event and Action Plan.
5.2
Setup of the Pre-construction Baseline Monitoring
5.2.1
Monitoring Locations
Eastern Tributary
As presented in Section 2.1 of the Monitoring Plan, the ecological and water quality baseline monitoring was conducted at a total of seven (7) monitoring locations at Tung Chung Stream covering both River Park and Public Works.
Study Area in association with River Park works – this part of monitoring includes four monitoring locations (RP1, RP2, RP3 and RP4), which cover the Conservation Zone (existing natural section), Revitalization Zone (existing channelised section to be completely revitalised at Construction stage), and both the upstream and downstream sections of Tung Chung Stream within 30 meters outside the boundary of River Park.
Study Area in association with Public Works – this part of monitoring includes three monitoring locations (PW1, PW2 and PW3), which are in the vicinity of Public Works area.
Locations of these monitoring stations are presented in Table 5.1 and Appendix D1. Representative photos of these monitoring stations are shown in Appendix D2. Note that the exact monitoring locations were subject to fine adjustment based on site conditions (e.g. adverse weather conditions, blockage by plants, rocks or other obstacles).
Table 5.1: Baseline Ecological and Water Quality Monitoring Stations (Eastern Tributary)
|
Description |
Coordinates |
||||
|
|
Easting |
Northing |
Latitude (N) |
Longitude (E) |
|
|
RP1 |
Conservation Zone (Natural Section) |
811150 |
814469 |
22°16'07.95"N |
113°55'59.41"E |
|
RP2 |
Upstream of River Park |
811083 |
814895 |
22°16'21.77"N |
113°55'57.05"E |
|
RP3 |
Revitalisation Zone (Channelised Section) |
811036 |
815076 |
22°16'27.66"N |
113°55'55.38"E |
|
RP4 |
Downstream of River Park |
810846 |
815402 |
22°16'38.25"N |
113°55'48.72"E |
|
PW1 |
Near Public Works |
811099 |
814589 |
22°16'11.83"N |
113°55'57.63"E |
|
PW2 |
Near Public Works |
810933 |
815318 |
22°16'35.54"N |
113°55'51.79"E |
|
PW3 |
Near Public Works |
810789 |
815658 |
22°16'46.56"N |
113°55'46.71"E |
Western Tributary
Refer to Section 2.1 of the Monitoring Proposal, the ecological and water quality baseline monitoring was conducted at a total of three (3) monitoring locations close to each Public Works area.
Locations of these monitoring stations are presented in Table 5.2 and Appendix D1. Representative photos of these monitoring stations are shown in Appendix D2. Note that the exact monitoring locations were subject to fine adjustment based on site conditions (e.g. adverse weather conditions, blockage by plants, rocks or other obstacles).
Study Area in association with Public Works – this part of monitoring includes three monitoring locations (PW4, PW5 and PW6), which are in the vicinity of Public Works Study area.
Table 5.2: Baseline Ecological and Water Quality Monitoring Stations (Western Tributary)
|
|
Description |
Coordinates |
|||
|
|
Easting |
Northing |
Latitude (N) |
Longitude (E) |
|
|
PW4 |
Near Public Works |
810782 |
814583 |
22°16' 11.6"N |
113°55' 46.56"E |
|
PW5 |
Near Public Works |
810795 |
814823 |
22°16' 19.45"N |
113°55' 46.99"E |
|
PW6 |
Near Public Works |
810815 |
815382 |
22°16' 37.6"N |
113°55' 47.64"E |
5.2.2
Monitoring Period and Frequency
According to Section 11.4.5 of the Updated EM&A Manual, pre-construction baseline monitoring shall be carried out on a monthly basis for a 12-month duration for River Park while that for Public Works (road crossings, polders, and stormwater attenuation and treatment ponds) shall be at least 6 months and covering the wet season.
Eastern Tributary
As presented in Section 2.2 of the Monitoring Plan, the ecological and water quality baseline monitoring was conducted at the Study Areas in association with River Park works (RP1, RP2, RP3 and RP4), and Public Works (PW1, PW2 and PW3) for a duration of 12 months and 6 months respectively. The monitoring schedule is shown in Table 5.3 below.
Study Area in association with River Park works – this part of monitoring was conducted once every month for a 12-month duration from August 2020 to July 2021.
Study Area in association with Public Works – this part of monitoring was conducted once every month for a 6-month duration from August 2020 to January 2021.
Table 5.3: Baseline Ecological and Water Quality Monitoring Schedule (Eastern Tributary)
|
Month |
River Park Study Area (RP1, RP2, RP3 and RP4) |
Public Works Study Area (PW1, PW2 and PW3) |
||
|
|
Ecological Monitoring |
Water Quality Monitoring |
Ecological Monitoring |
Water Quality Monitoring |
|
Aug 2020 |
21 & 24 Aug 2020 |
21 Aug 2020 |
21 & 24 Aug 2020 |
21 Aug 2020 |
|
Sep 2020 |
15 & 25 Sep 2020 |
15 Sep 2020 |
15 & 25 Sep 2020 |
15 Sep 2020 |
|
Oct 2020 |
20 & 22 Oct 2020 |
20 Oct 2020 |
20 & 22 Oct 2020 |
20 Oct 2020 |
|
Nov 2020 |
18 & 19 Nov 2020 |
18 Nov 2020 |
18 & 19 Nov 2020 |
18 Nov 2020 |
|
Dec 2020 |
16 & 17 Dec 2020 |
17 Dec 2020 |
16 & 17 Dec 2020 |
17 Dec 2020 |
|
Jan 2021 |
15 & 18 Jan 2021 |
15 Jan 2021 |
15 & 18 Jan 2021 |
15 Jan 2021 |
|
Feb 2021 |
18 Feb 2021 |
18 Feb 2021 |
- |
- |
|
Mar 2021 |
26 Mar 2021 |
26 Mar 2021 |
- |
- |
|
Apr 2021 |
22 Apr 2021 |
22 Apr 2021 |
- |
- |
|
May 2021 |
17 May 2021 |
17 May 2021 |
- |
- |
|
Jun 2021 |
25 Jun 2021 |
25 Jun 2021 |
- |
- |
|
Jul 2021 |
14 Jul 2021 |
14 Jul 2021 |
- |
- |
Western Tributary
Refer to Section 2.2 of the Monitoring Proposal, the ecological and water quality baseline monitoring was conducted at the Study Areas in the vicinity of the Public Works Areas (PW4, PW5 and PW6) from May 2023 to March 2024. The monitoring schedule is shown in Table 5.4 below.
Table 5.4: Baseline Ecological and Water Quality Monitoring Schedule (Western Tributary)
|
Month |
Public Works Study Area (PW4, PW5 and PW6) |
|
|
|
Ecological Monitoring |
Water Quality Monitoring |
|
May 2023 |
18 May 2023 |
18 May 2023 |
|
July 2023 |
13 Jul 2023 |
13 Jul 2023 |
|
Sept 2023 |
12 Sep 2023 |
12 Sep 2023 |
|
Nov 2023 |
16 Nov 2023 |
16 Nov 2023 |
|
Jan 2024 |
16 Jan 2024 |
16 Jan 2024 |
|
Mar 2024 |
12 Mar 2024 |
12 Mar 2024 |
5.2.3
Monitoring Requirement
According to Section 11.4.5 of the Updated EM&A Manual, the monitoring items should cover the environment of the stream courses, the water quality, and the stream fauna (“aquatic fauna”, as adopted by the Monitoring Report). Ecological monitoring of stream fauna should include fish and aquatic invertebrate, while the methodology should follow standard methods of direct observation and active search. The frequency should be monthly.
5.2.4
Monitoring Methodology
5.2.4.1
Aquatic
Fauna
As presented in Section 3.1 of the Monitoring Plan, monitoring of aquatic fauna (includes fish and aquatic invertebrates) at the River Park and Public Works Study Areas were conducted in accordance with the methodology following relevant annex of EIAO-TM (Annex 16) and the EIAO Guidance Notes (GN 6/2010, GN 7/2010, GN 10/2010 and GN 11/2010). Several survey methods which covered different components of the stream fauna were used to monitor the Study Areas to yield a comprehensive result.
Direct observation and active search were conducted within the survey zones/sections. Direct observation covered all along the accessible part of the watercourse to provide a species list of fish and invertebrates with corresponding relative abundance.
Direct observation is a simple and least intrusive method to survey fish which is suitable to conduct in shallow, slow-moving streams with clear water and with minimal vegetation; while active search is used to collect fishes and aquatic invertebrates in deeper water, in turbid locations, in stream with dense aquatic vegetation and within stream substrate.
At each sampling location, two replicates of baited fish cages were deployed for a duration of at least one hour. All collected fish and other aquatic invertebrate species were recorded and their abundance were counted. This method may collect fishes which are wary of humans. Permit from the AFCD was obtained before the use of any equipment to collect aquatic fauna in any streams and watercourses.
Besides baited fish cages, at least two replicates of kick sampling were performed at each monitoring station to obtain invertebrate (and fish) samples. Kick sampling is a relatively quick method to survey benthic invertebrates in shallow fast-flowing streams. A ~30 cm x ~30 cm kick sampler with ~0.5 mm mesh size was placed on the stream bed and the area just upstream of the sampler were vigorously disturbed by kicking for one minute. The contents of the net were transferred to suitable containers with freshwater for identification and counting in situ. All identifiable samples were released back to the sampling locations. If there were unidentifiable samples, representative samples would be preserved with ethanol and transferred to laboratory for further identification.
5.2.4.2
Water Quality
The monitoring methodology including water quality parameters, monitoring procedures, instrument required and methods for in situ measurement and laboratory analyses were set as presented in Section 3.2 of the Monitoring Plan.
Water quality monitoring, including in situ measurements and collection of water samples for laboratory analysis, was conducted at each monitoring location. Duplicate water samples were collected at surface water level at each sampling location.
Water quality parameters including Dissolved Oxygen (in % saturation and mg/L), pH value, temperature, turbidity and salinity were measured in situ while the other parameters, including Suspended Solids (SS), Ammonia, Total Kjeldahl Nitrogen (TKN), Total Phosphorus (TP), Escherichia coli (E. coli), 5-day Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD) and Oil & Grease, were measured at a HOKLAS accredited laboratory for water quality analysis. Other relevant data, including time, water depth, weather conditions and special phenomena or works underway in the vicinity were recorded.
The measured water quality parameters and laboratory testing method are shown in Table 5.5.
Table 5.5: Water Quality Monitoring Parameters and Testing Methods
|
Parameter |
|
|
|
In situ measurements |
Instrument Range Capability (1) |
Measurement Resolution |
|
pH |
0 – 14 pH units |
0.01 pH units |
|
Salinity |
0 – 70 ppt |
0.01 ppt |
|
Temperature |
-5 – 70°C |
0.1°C |
|
Turbidity |
0 – 1000 NTU |
0.1 NTU |
|
Dissolved Oxygen (DO) |
0 – 50 mg/L |
0.1 mg/L |
|
|
0 – 500% saturation |
0.1% saturation |
|
Laboratory testing and analyses |
Method Reference |
Level of Reporting |
|
Suspended Solids (SS) |
APHA 2540 D |
0.5 mg/L |
|
Ammonia as N |
APHA 4500 NH3 G |
0.01 mg/L |
|
Total Kjeldahl Nitrogen (TKN) as N |
APHA
4500 P: J; |
0.05 mg/L |
|
Total Phosphorus as P |
APHA 4500 P: J |
0.01 mg/L |
|
E. coli |
TM09/EC/10/98 Issue 3, HKEPD |
1 CFU/100mL |
|
5-day Biochemical Oxygen Demand (BOD5) |
APHA 5210 B |
1 mg/L |
|
Chemical Oxygen Demand (COD) |
APHA 5220 B |
2 mg/L |
|
Oil & Grease |
APHA 5520 B |
2 mg/L |
Note (1): Specifications based on YSI ProDSS Multiparameter Water Quality Meter
5.2.5
Monitoring Result
5.2.5.1
Site Conditions
Eastern Tributary
As extracted from the Monitoring Report, the physical environment of the monitoring stations for the River Park Study Area (RP1 to RP4) and Public Works Study Area (PW1 to PW3) are summarized and presented in Table 5.6.
Table 5.6: Physical Environment of the Monitoring Stations (Eastern Tributary)
|
Location |
Physical Environment |
|
|
RP1 |
Conservation Zone (Natural Section) |
Fast flowing natural stream. The substrate was dominant with boulders and rocks, and sands were sometimes observed. Water was generally clear and the river depth varied which was usually within 60cm. Woodland with dense vegetation was on the river banks. |
|
RP2 |
Upstream of River Park |
Moderate fast flowing natural stream. The substrate was in the form of boulders, rocks, sand and silt mixture. Water was generally clear and the river depth varied which was usually within 50cm. Short but dense herbaceous vegetation was on the right bank of the stream, while dense woodland was on the left bank. Household wastes, such as food packages, were observed near the left bank of the stream. |
|
RP3 |
Revitalisation Zone (Channelised Section) |
Slow flowing artificial, concretised and channelised stream. Pavement was the dominant substrate with little sand and rock. Algal mat was observed at this site. Water was generally clear and the river depth was usually within 10cm. Short but dense herbaceous vegetation was on the river banks. A culvert was on the right bank of the stream, and a footbridge was on the upstream of the location. |
|
RP4 |
Downstream of River Park |
The channelised section of Tung Chung Stream ended at the upstream of RP4. RP4 is a moderate fast flowing natural stream close to the estuary, so the physical and biochemical parameters are affected by the estuary and tidal activities. The substrate was in the form of boulders, rocks, sand and silt mixture. Water was sometimes clear and the river depth varied which was usually within 80cm. Woody plants and herbaceous plants were along the river banks. Dead vegetation was observed in the stream in the first few months of survey, which was then cleared. The dead vegetation was observed to be shelter of some fishes and aquatic invertebrates. Household wastes, such as food packages and abandoned furniture, were frequently observed in the stream or on the river bank. |
|
PW1 |
Near Public Works |
Fast flowing natural stream. The substrate was dominant with boulders and rocks, and sand was sometimes observed. Water was generally clear and the river depth varied which was usually within 40cm. Woodland with dense vegetation was on the river banks. |
|
PW2 |
Near Public Works |
Slow flowing artificial, concretised and channelised stream. Pavement was the dominant substrate with little sand and rock. Algal mat was observed at this site. Water was generally clear and the river depth varied which was usually within 15cm. Short but dense herbaceous vegetation was on the left bank of the stream, woody plants and herbaceous plants were on right bank of the river. |
|
PW3 |
Near Public Works |
A natural estuary. Water was brown, slow flowing and usually turbid. Water depth varied which was usually within 110cm. The substrate was dominant with sand and mud. Dense mangroves were on the shores of the estuary. |
Western Tributary
The physical environment of the monitoring stations for the Public Works Study Area (PW4 to PW6) are summarized and presented in Table 5.7.
Table 5.7: Physical Environment of the Monitoring Sations (Western Tributary)
|
Station Name |
Location |
Physical Environment |
|
PW4 |
Near Public Works |
Fast flowing natural stream. The substrate was dominant with boulders and rocks. Water was clear and the river depth varied which was usually within 120cm. Woodland with dense vegetation was on one side of the river banks, while dense herbaceous vegetation was observed on the other side. |
|
PW5 |
Near Public Works |
Fast flowing natural stream. The substrate was dominant with rocks. Water was clear and the river depth varied which was usually within 40cm. Dense herbaceous vegetation and occasionally woody and shrubby vegetation were found on both sides of the banks. Dense herbaceous vegetation was also observed in the middle of the stream during wet season. |
|
PW6 |
Near Public Works |
Moderately fast flowing natural stream. The substrate was dominant with rocks with little sand. Water was generally clear. Brown algae was commonly observed on the substrate, and green algal mats were found on rocks. The river depth varied which was usually within 30cm. Dense shrubs and herbaceous vegetation were observed on the banks. |
5.2.5.2
Taxa Diversity
of Aquatic Fauna
Eastern Tributary
Three (3) types of survey were conducted, which are (i) Direct Observation, (ii) Kick Sampling, and (iii) Baited Fish Cage. Taxa diversity, i.e. number of species, of each monitoring station was obtained based on the cumulative count of species recorded in the three survey methods over the entire 12-month survey period. The cumulative result on taxa diversity of aquatic invertebrate and fish have been summarised in Table 5.8 and Table 5.9 respectively. Full details of the cumulative data extracted from the Monitoring Report are listed in Appendix D3.1 and Appendix D4.1.
Aquatic Invertebrate – For both River Park and Public Works Study Area, a total of 20 aquatic invertebrate species was recorded, respectively with station RP4 supporting the highest number of species, i.e. 14. The species recorded comprises of macroinvertebrates(1) such as shrimp, crab, snail, dragonfly larvae and water strider. Besides, two (2) species of mosquito larvae, Chironomidae sp. and Tipulidae sp., and one (1) species of water mite was recorded.
Fish – For both River Park and other Public Works Study Areas, a total of 28 fish species was recorded, with stations RP4 and PW3 support the highest number of species, i.e., 18 and 12 respectively. The relatively high taxa diversity in these stations is largely due to its proximity to river mouth in which the fish community comprises of the estuarine fish.
Note (1): For effective evaluation of the monitoring result, only macroinvertebrates will be accounted in the consideration of Action and Limit Levels.
Table 5.8: Cumulative Record of Aquatic Invertebrate Species (Eastern Tributary)
|
Common Name |
Species Name |
River Park Study Area |
Public Works Study Area |
|||||
|
|
|
RP1 |
RP2 |
RP3 |
RP4 |
PW1 |
PW2 |
PW3 |
|
Freshwater Shrimp |
Caridina cantonensis |
✔ |
✔ |
✔ |
✔ |
|||
|
Freshwater Prawn |
Macrobrachium sp. |
✔ |
✔ |
✔ |
✔ |
✔ |
||
|
- |
Amphipoda |
✔ |
||||||
|
Crab |
Varuna litterata |
✔ |
✔ |
✔ |
||||
|
Mitten Crab |
Eriocheir japonica |
✔ |
✔ |
✔ |
✔ |
|||
|
- |
Parasesarma bidens |
✔ |
||||||
|
- |
Portunus sp. |
✔ |
||||||
|
Freshwater Snail |
Clithon retropictus |
✔ |
✔ |
✔ |
||||
|
- |
Radix plicatulus |
✔ |
✔ |
|||||
|
- |
Tarebia granifera |
✔ |
✔ |
✔ |
||||
|
Common Blue Jewel |
Heliocypha perforata |
✔ |
||||||
|
Chinese Greenwing (Larva) |
Neurobasis chinensis |
✔ |
✔ |
|||||
|
Emerald Cascader (Larva) |
Zygonyx iris (1) |
✔ |
✔ |
✔ |
✔ |
✔ |
||
|
- |
Ephemeroptera sp. |
✔ |
||||||
|
Unidentified Skimmer (Larva) |
Orthetrum sp. |
✔ |
✔ |
✔ |
✔ |
✔ |
||
|
Water Strider |
Ptilomera tigrina |
✔ |
✔ |
✔ |
✔ |
✔ |
✔ |
|
|
- |
Rhagovelia sp. |
✔ |
✔ |
✔ |
||||
|
Blood Worm (2) |
Chironomidae sp. |
✔ |
✔ |
✔ |
||||
|
Cranefly Larva |
Tipulidae sp. (2) |
✔ |
||||||
|
Water Mites |
Hydrachnidae sp. (2) |
✔ |
✔ |
✔ |
✔ |
|||
|
Cumulative Number of Aquatic Invertebrate Species |
9 |
8 |
8 |
14 |
5 |
9 |
5 |
|
|
Cumulative Number of Macroinvertebrate Species |
8 |
7 |
7 |
12 |
4 |
7 |
5 |
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Blood Worm Chironomidae sp., Cranefly Larva Tipulidae sp., and Water Mites Hydrachnidae sp. are not counted as macroinvertebrates.
Table 5.9: Cumulative Record of Fish Species (Eastern Tributary)
|
Common Name |
Species Name |
River Park Study Area |
Public Works Study Area |
|||||
|
|
|
RP1 |
RP2 |
RP3 |
RP4 |
PW1 |
PW2 |
PW3 |
|
Yellowfin Seabream |
Acanthopagrus latus |
✔ |
✔ |
|||||
|
Beijiang Thick-lipped Barb |
Acrossocheilus beijiangensis (1) |
✔ |
✔ |
✔ |
✔ |
|||
|
Asiatic Glassfish |
Ambassis sp. |
✔ |
✔ |
|||||
|
Chinese Barb |
Barbodes semifasciolatus |
✔ |
✔ |
✔ |
||||
|
Redbelly Tilapia |
Coptodon zillii |
✔ |
||||||
|
Black Sleeper |
Eleotris melanosoma |
✔ |
||||||
|
Indo-Pacific Tropical Sand Goby |
Favonigobius reichei |
✔ |
||||||
|
Mosquito Fish |
Gambusia affinis |
✔ |
✔ |
|||||
|
Long Rayed Silverbiddy |
Gerres filamentosus |
✔ |
||||||
|
Common Silverbiddy |
Gerres oyena |
✔ |
✔ |
|||||
|
Fork Tongue Goby |
Glossogobius giuris |
✔ |
✔ |
|||||
|
Jewelfish |
Hemichromis stellifer |
✔ |
||||||
|
Broken-band Hillstream Loach |
Liniparhomaloptera disparis |
✔ |
✔ |
✔ |
||||
|
Grey Mullet |
Mugil cephalus |
✔ |
✔ |
|||||
|
Mullet |
Mugilidae |
✔ |
||||||
|
Rice Fish |
Oryzias curvinotus (1) |
✔ |
||||||
|
Predaceous Chub |
Parazacco spilurus (2) |
✔ |
✔ |
✔ |
✔ |
✔ |
✔ |
|
|
Common Mudskipper |
Periophthalmus modestus |
✔ |
||||||
|
Sucker-belly Loach |
Pseudogastromyzon myersi |
✔ |
✔ |
✔ |
||||
|
Javanese Fatnose Goby |
Pseudogobius javanicus |
✔ |
||||||
|
- |
Rhinogobius duospilus |
✔ |
✔ |
✔ |
✔ |
|||
|
Barcheek Goby |
Rhinogobius giurinus |
✔ |
||||||
|
Spotted Scat |
Scatophagus argus |
✔ |
✔ |
|||||
|
Striped Loach |
Schistura fasciolata |
✔ |
✔ |
✔ |
||||
|
Jarbua Terapon |
Terapon jarbua |
✔ |
||||||
|
Chameleon Goby |
Tridentiger trigonocephalus |
✔ |
✔ |
|||||
|
Swordtail |
Xiphophorus hellerii |
✔ |
✔ |
✔ |
✔ |
✔ |
||
|
Variable Platyfish |
Xiphophorus variatus |
✔ |
✔ |
✔ |
✔ |
✔ |
✔ |
|
|
Cumulative Number of Fish Species |
9 |
10 |
4 |
18 |
9 |
2 |
12 |
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Species of conservation importance (Yue & Chen, 1998)
Western Tributary
Three (3) types of survey were conducted, which are (i) Direct Observation, (ii) Kick Sampling, and (iii) Baited Fish Cage. Taxa diversity, i.e. number of species, of each monitoring station was obtained based on the cumulative count of species recorded in the three survey methods over the entire survey period. The cumulative result on taxa diversity of aquatic invertebrate and fish have been summarised in Table 5.10 and Table 5.11 respectively. Full details of the cumulative data are listed in Appendix D3.2 and Appendix D4.2.
Aquatic Invertebrate – For Public Works Study Area, a total of 24 aquatic invertebrate species was recorded, with station PW6 demonstrating the highest number of species, i.e. 15. The species recorded comprises of macroinvertebrates(1) such as shrimp, crab, snail, dragonfly larvae and water strider. Besides, two (2) species of mosquito larvae, Chironomidae sp. and Tipulidae sp. were recorded.
Fish – For Public Works Study Area, a total of 18 fish species was recorded, with station PW6 supporting the highest number of species, i.e.,12. The relatively high taxa diversity in this station is largely due to its proximity to river mouth in which the fish community comprises of the estuarine fish.
Note (1): For effective evaluation of the monitoring result, only macroinvertebrates will be accounted in the consideration of Action and Limit Levels.
Table 5.10 : Cumulative Record of Aquatic Invertebrate Species (Western Tributary)
|
Common Name |
Species Name |
Public Works Study Area |
||
|
|
|
PW4 |
PW5 |
PW6 |
|
Small Minnow Mayfly (Larva) |
Baetidae sp. |
✔ |
✔ |
✔ |
|
Mayfly (Larva) |
Caenidae sp. |
✔ |
✔ |
|
|
Freshwater Shrimp |
Caridina cantonensis |
✔ |
✔ |
|
|
Blood Worm |
Chironomidae sp. (2) |
✔ |
✔ |
✔ |
|
Freshwater Snail |
Clithon retropictus |
✔ |
||
|
Water Boatman |
Corixidae sp. |
✔ |
||
|
Burrowing Mayfly (Larva) |
Ephemeridae sp. |
✔ |
||
|
Mitten Crab |
Eriocheir japonica |
✔ |
||
|
Black-banded Gossamerwing (Larva) |
Euphaea decorata |
✔ |
✔ |
|
|
Mayfly (Larva) |
Heptageniidae sp. |
✔ |
✔ |
✔ |
|
Caddisfly (Larva) |
Hydropsychidae sp. |
✔ |
✔ |
|
|
Caddisfly (Larva) |
Leptoceridae sp. |
✔ |
||
|
Prong-gilled Mayfly (Larva) |
Leptophlebiidae sp. |
✔ |
✔ |
✔ |
|
Freshwater Prawn |
Macrobrachium sp. |
✔ |
✔ |
|
|
Freshwater Snail |
Melanoides tuberculata |
✔ |
||
|
Small Pond Skater |
Metrocoris lituratus |
✔ |
||
|
Stonefly (Larva) |
Perlidae sp. |
✔ |
||
|
Caddisfly (Larva) |
Philopotamidae sp. |
✔ |
||
|
Water Strider |
Ptilomera tigrina |
✔ |
✔ |
✔ |
|
Smaller Water Strider |
Rhagovelia sp. |
✔ |
✔ |
✔ |
|
Caddisfly (Larva) |
Rhyacophilidae sp. |
|
✔ |
|
|
Freshwater Snail |
Tarebia granifera |
|
|
✔ |
|
Cranefly (Larva) |
Tipulidae sp. (2) |
✔ |
✔ |
✔ |
|
Emerald Cascader (Larva) |
Zygonyx iris (1) |
|
✔ |
|
|
Cumulative Number of Aquatic Invertebrate Species |
14 |
14 |
15 |
|
|
Cumulative Number of Macroinvertebrate Species |
12 |
12 |
13 |
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Blood Worm Chironomidae sp. and Cranefly Larva Tipulidae sp. are not counted as macroinvertebrates.
Table 5.11: Cumulative Record of Fish Species (Western Tributary)
|
Common Name |
Species Name |
Public Works Study Area |
||
|
|
|
PW4 |
PW5 |
PW6 |
|
Beijiang Thick-lipped Barb |
Acrossocheilus beijiangensis (1) |
✔ |
✔ |
✔ |
|
Chinese Barb |
Barbodes semifasciolatus |
✔ |
✔ |
✔ |
|
Mud Carp |
Cirrhinus molitorella (3) |
✔ |
||
|
Koi |
Cyprinus rubrofuscus |
✔ |
||
|
Mosquito Fish |
Gambusia affinis |
✔ |
||
|
Fork Tongue Goby |
Glossogobius giuris |
✔ |
||
|
Jewelfish |
Hemichromis stellifer |
✔ |
✔ |
|
|
Broken-band Hillstream Loach |
Liniparhomaloptera disparis |
✔ |
✔ |
|
|
Mullet |
Mugilidae |
✔ |
||
|
Rice Fish |
Oryzias curvinotus (1) |
✔ |
||
|
Predaceous Chub |
Parazacco spilurus (2) |
✔ |
✔ |
✔ |
|
Sucker-belly Loach |
Pseudogastromyzon myersi |
✔ |
✔ |
|
|
- |
Rhinogobius duospilus |
✔ |
✔ |
|
|
Barcheek Goby |
Rhinogobius giurinus |
✔ |
||
|
Striped Loach |
Schistura fasciolata |
✔ |
||
|
Chameleon Goby |
Tridentiger trigonocephalus |
✔ |
||
|
Swordtail |
Xiphophorus hellerii |
✔ |
✔ |
✔ |
|
Variable Platyfish |
Xiphophorus variatus |
✔ |
✔ |
|
|
Cumulative Number of Fish Species |
10 |
9 |
12 |
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Species of conservation importance (Yue & Chen, 1998)
Note (3): Species of conservation importance (IUCN, 2024)
5.2.5.3
Abundance of
Aquatic Fauna
Eastern Tributary
As the abundance of aquatic fauna presented in the Monitoring Report were recorded by a mix of quantitative sampling methods (baiting and kick sampling) and qualitative estimate (direct observation), the abundance can only be indicatively presented.
As stipulated in the Monitoring Report, the occurrence frequency for the aquatic invertebrate and fish species, which refers to the number of surveys in which each species was encountered over the survey period (i.e. 12 months for River Park Study Area and 6 months for Public Works Study Area), is summarised in Table 5.12 and Table 5.13 respectively. This could reveal the commonness of the species in the Study Areas. The details on the abundance of aquatic fauna extracted from the Monitoring Report are presented in Appendix D5.1 and Appendix D6.1.
Aquatic Invertebrate – among the macroinvertebrate species recorded, Freshwater Shrimp Cardina cantonensis, Macrobrachium sp., Orthetrum sp., Water Strider Ptilomera tigrine, and Emerald Cascader (Larva) Zygonyx iris are relatively common across various monitoring stations.
Fish – Among the fish species recorded, Predaceous Chub Parazacco spilurus and Variable Platyfish Xiphophorus variatus are commonly recorded in most of the survey, except station PW3, which is mostly influenced by estuarine environment. A species of conservation importance, Beijiang Thick-lipped Barb Acrossocheilus beijiangensis, was commonly recorded across stations RP1, RP2, RP4 and PW1. It is worth noting that another species of conservation importance Rice Fish Oryzias curvinotus is restricted in RP4 but quite regularly observed.
Table 5.12 : Occurrence Frequency of Aquatic Invertebrate Species Recorded (Eastern Tributary)
|
Common Name |
Species Name |
River Park Study Area |
Public Works Study Area |
|||||
|
|
|
RP1 |
RP2 |
RP3 |
RP4 |
PW1 |
PW2 |
PW3 |
|
Freshwater Shrimp |
Caridina cantonensis |
11 |
8 |
|
3 |
3 |
|
|
|
Freshwater Prawn |
Macrobrachium sp. |
6 |
4 |
|
5 |
2 |
2 |
|
|
- |
Amphipoda |
|
|
|
|
|
|
1 |
|
Crab |
Varuna litterata |
|
|
1 |
3 |
|
|
2 |
|
Mitten Crab |
Eriocheir japonica |
2 |
|
2 |
1 |
2 |
|
|
|
- |
Parasesarma bidens |
|
|
|
|
|
|
2 |
|
- |
Portunus sp. |
|
|
|
|
|
|
2 |
|
Freshwater Snail |
Clithon retropictus |
|
|
6 |
4 |
|
4 |
|
|
- |
Radix plicatulus |
|
|
1 |
1 |
|
|
|
|
- |
Tarebia granifera |
|
|
3 |
10 |
|
3 |
|
|
Common Blue Jewel |
Heliocypha perforata |
1 |
|
|
|
|
|
|
|
Chinese Greenwing (Larva) |
Neurobasis chinensis |
|
1 |
|
1 |
|
|
|
|
Emerald Cascader (Larva) |
Zygonyx iris (1) |
1 |
2 |
2 |
1 |
|
5 |
|
|
- |
Ephemeroptera sp. |
|
|
|
|
|
2 |
|
|
Unidentified Skimmer (Larva) |
Orthetrum sp. |
1 |
2 |
3 |
5 |
|
5 |
|
|
Water Strider |
Ptilomera tigrina |
9 |
3 |
|
2 |
3 |
2 |
2 |
|
- |
Rhagovelia sp. |
1 |
1 |
|
2 |
|
|
|
|
Blood Worm |
Chironomidae sp. |
|
|
1 |
1 |
|
4 |
|
|
Cranefly Larva |
Tipulidae sp. (2) |
|
|
|
|
|
1 |
|
|
Water Mites |
Hydrachnidae sp. (2) |
2 |
1 |
|
1 |
1 |
|
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Blood Worm Chironomidae sp., Cranefly Larva Tipulidae sp., and Water Mites Hydrachnidae sp. are not counted as macroinvertebrates.
Table 5.13: Occurrence Frequency of Fish Species Recorded (Eastern Tributary)
|
Common Name |
Species Name |
River Park Study Area |
Public Works Study Area |
|||||
|
RP1 |
RP2 |
RP3 |
RP4 |
PW1 |
PW2 |
PW3 |
||
|
Yellowfin Seabream |
Acanthopagrus latus |
|
|
|
9 |
|
|
6 |
|
Beijiang Thick-lipped Barb |
Acrossocheilus beijiangensis (1) |
7 |
7 |
|
3 |
5 |
|
|
|
Asiatic Glassfish |
Ambassis sp. |
|
|
|
3 |
|
|
1 |
|
Chinese Barb |
Barbodes semifasciolatus |
3 |
5 |
|
|
1 |
|
|
|
Redbelly Tilapia |
Coptodon zillii |
|
|
|
1 |
|
|
|
|
Black Sleeper |
Eleotris melanosoma |
|
|
|
|
|
|
1 |
|
Indo-Pacific Tropical Sand Goby |
Favonigobius reichei |
|
|
|
|
|
|
1 |
|
Mosquito Fish |
Gambusia affinis |
|
|
2 |
1 |
|
|
|
|
Long Rayed Silverbiddy |
Gerres filamentosus |
|
|
|
|
|
|
1 |
|
Common Silverbiddy |
Gerres oyena |
|
|
|
3 |
|
|
4 |
|
Fork Tongue Goby |
Glossogobius giuris |
|
|
|
12 |
|
|
1 |
|
Jewelfish |
Hemichromis stellifer |
|
|
|
7 |
|
|
|
|
Broken-band Hillstream Loach |
Liniparhomaloptera disparis |
8 |
4 |
|
|
2 |
|
|
|
Grey Mullet |
Mugil cephalus |
|
|
|
8 |
|
|
6 |
|
Mullet |
Mugilidae |
|
|
|
1 |
|
|
|
|
Rice Fish |
Oryzias curvinotus (1) |
|
|
|
10 |
|
|
|
|
Predaceous Chub |
Parazacco spilurus (2) |
12 |
11 |
1 |
4 |
6 |
1 |
|
|
Common Mudskipper |
Periophthalmus modestus |
|
|
|
|
|
|
2 |
|
Sucker-belly Loach |
Pseudogastromyzon myersi |
8 |
4 |
|
|
4 |
|
|
|
Javanese Fatnose Goby |
Pseudogobius javanicus |
|
|
|
|
|
|
5 |
|
- |
Rhinogobius duospilus |
10 |
11 |
|
5 |
3 |
|
|
|
Barcheek Goby |
Rhinogobius giurinus |
|
|
|
6 |
|
|
|
|
Spotted Scat |
Scatophagus argus |
|
|
|
1 |
|
|
4 |
|
Striped Loach |
Schistura fasciolata |
7 |
4 |
|
|
2 |
|
|
|
Jarbua Terapon |
Terapon jarbua |
|
|
|
|
|
|
5 |
|
Chameleon Goby |
Tridentiger trigonocephalus |
|
1 |
|
2 |
|
|
|
|
Swordtail |
Xiphophorus hellerii |
7 |
6 |
3 |
2 |
3 |
|
|
|
Variable Platyfish |
Xiphophorus variatus |
3 |
7 |
4 |
3 |
6 |
5 |
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Species of conservation importance (Yue & Chen,1998)
Western Tributary
As the abundance of aquatic fauna presented in the Monitoring Report were recorded by a mix of quantitative sampling methods (baiting and kick sampling) and qualitative estimate (direct observation), the abundance can only be indicatively presented.
As stipulated in the Monitoring Report, the occurrence frequency for the aquatic invertebrate and fish species, which refers to the number of surveys in which each species was encountered over the survey period (i.e. 6 months for Public Works Study Area), is summarised in Table 5.14 and Table 5.15 respectively. This could reveal the commonness of the species in the Study Area. The details on the abundance of aquatic fauna extracted from the Monitoring Report are presented in Appendix D5.2 and Appendix D6.2.
Aquatic Invertebrate – among the macroinvertebrate species recorded, Water Strider Ptilomera tigrina , Small Minnow Mayfly (Larva) Baetidae sp., Black-banded Gossamerwing (Larva) Euphaea decorata, Mayfly (Larva) Heptageniidae sp. and Prong-gilled Mayfly (Larva) Leptophlebiidae sp. are relatively common across various monitoring stations.
Fish – Among the fish species recorded, Predaceous Chub Parazacco spilurus and Beijiang Thick-lipped Barb Acrossocheilus beijiangensis, which were species of conservation importance, were most commonly recorded across all stations in the western tributary. It is worth noting that another species of conservation importance Rice Fish Oryzias curvinotus was also observed in PW6.
Table 5.14: Occurrence Frequency of Aquatic Invertebrate Species Recorded (Western Tributary)
|
Common Name |
Species Name |
Public Works Study Area |
||
|
|
|
PW4 |
PW5 |
PW6 |
|
Small Minnow Mayfly (Larva) |
Baetidae sp. |
1 |
3 |
2 |
|
Mayfly (Larva) |
Caenidae sp. |
1 |
2 |
|
|
Freshwater Shrimp |
Caridina cantonensis |
1 |
|
2 |
|
Blood Worm |
Chironomidae sp. (2) |
3 |
2 |
1 |
|
Freshwater Snail |
Clithon retropictus |
|
|
1 |
|
Water Boatman |
Corixidae |
1 |
|
|
|
Burrowing Mayfly (Larva) |
Ephemeridae |
1 |
|
|
|
Mitten Crab |
Eriocheir japonica |
|
|
2 |
|
Black-banded Gossamerwing (Larva) |
Euphaea decorata |
1 |
3 |
|
|
Mayfly (Larva) |
Heptageniidae |
2 |
1 |
1 |
|
Caddisfly (Larva) |
Hydropsychidae |
|
1 |
2 |
|
Caddisfly (Larva) |
Leptoceridae |
|
1 |
|
|
Prong-gilled Mayfly (Larva) |
Leptophlebiidae |
3 |
2 |
1 |
|
Freshwater Prawn |
Macrobrachium sp. |
1 |
|
1 |
|
Freshwater Snail |
Melanoides tuberculata |
|
|
3 |
|
Small Pond Skater |
Metrocoris lituratus |
|
|
2 |
|
Stonefly (Larva) |
Perlidae |
1 |
|
|
|
Caddisfly (Larva) |
Philopotamidae |
|
1 |
|
|
Water Strider |
Ptilomera tigrina |
6 |
2 |
5 |
|
Smaller Water Strider |
Rhagovelia sp. |
1 |
1 |
2 |
|
Caddisfly (Larva) |
Rhyacophilidae |
|
1 |
|
|
Freshwater Snail |
Tarebia granifera |
|
|
1 |
|
Cranefly (Larva) |
Tipulidae (2) |
1 |
2 |
1 |
|
Emerald Cascader (Larva) |
Zygonyx iris (1) |
|
1 |
|
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Blood Worm Chironomidae sp. and Cranefly Larva Tipulidae sp. are not counted as macroinvertebrates.
Table 5.15 : Occurrence Frequency of Fish Species Recorded (Western Tributary)
|
Common Name |
Species Name |
Public Works Study Area |
||
|
PW4 |
PW5 |
PW6 |
||
|
Beijiang Thick-lipped Barb |
Acrossocheilus beijiangensis (1) |
6 |
5 |
1 |
|
Chinese Barb |
Barbodes semifasciolatus |
2 |
2 |
2 |
|
Mud Carp |
Cirrhinus molitorella (3) |
6 |
|
|
|
Koi |
Cyprinus rubrofuscus |
|
|
1 |
|
Mosquito Fish |
Gambusia affinis |
|
|
2 |
|
Fork Tongue Goby |
Glossogobius giuris |
|
|
3 |
|
Jewelfish |
Hemichromis stellifer |
4 |
1 |
|
|
Broken-band Hillstream Loach |
Liniparhomaloptera disparis |
6 |
1 |
|
|
Mullet |
Mugilidae |
|
|
3 |
|
Rice Fish |
Oryzias curvinotus (1) |
|
|
4 |
|
Predaceous Chub |
Parazacco spilurus (2) |
6 |
6 |
6 |
|
Sucker-belly Loach |
Pseudogastromyzon myersi |
3 |
1 |
|
|
- |
Rhinogobius duospilus |
2 |
6 |
|
|
Barcheek Goby |
Rhinogobius giurinus |
|
|
3 |
|
Striped Loach |
Schistura fasciolata |
1 |
|
|
|
Chameleon Goby |
Tridentiger trigonocephalus |
|
|
2 |
|
Swordtail |
Xiphophorus hellerii |
1 |
6 |
6 |
|
Variable Platyfish |
Xiphophorus variatus |
|
2 |
1 |
Note (1): Species of conservation importance (Fellowes, 2002)
Note (2): Species of conservation importance (Yue & Chen,1998)
Note (3): Species of conservation importance (IUCN, 2024)
5.2.5.4
Species of
Conservation Importance
Aquatic Invertebrate – One aquatic invertebrate species of conservation importance was recorded. Emerald Cascader (Larva) Zygonyx iris is considered Potential Global Concern by Fellowes (2002).
Fish – A total of 4 fish species with conservation importance was recorded. These include Beijiang Thick-lipped Barb Acrossocheilus beijiangensis and Rice Fish Oryzias curvinotus, both of which are considered Global Concern by Fellowes (2002); Predaceous Chub Parazacco spilurus is considered Vulnerable status in China Red Data Book of Endangered Animals (Yue & Chen 1998); and Mud Carp Cirrhinus molitorella, which is considered as Near Threatened by the IUCN Red List of Threatened Species (2024). It is worth noting that the Rice Fish Oryzias curvinotus was only recorded in monitoring station RP4 and PW6, and Mud Carp Cirrhinus molitorella was only recorded in monitoring station PW4.
Representative photos of the species of conservation importance are presented in Appendix D7.
5.2.5.5
Water Quality
The water quality monitoring results extracted from the Monitoring Report, are summarised in terms of medians / geometric means and ranges of the 12-month / 6-month data and interpreted with reference to the Water Quality Objectives (WQOs, with five (5) representative parameters including pH, DO in mg/L, SS, BOD5 and COD) of Tung Chung Stream as set by the EPD. The data summary and details of the cumulative water quality data for eastern tributary extracted from the Monitoring Report are listed in Appendix D8.1.
River Park Study Area
Water quality monitoring results were generally similar across stations RP1, RP2 and RP3 where they are at the relatively upstream part of Tung Chung Stream. Levels of E. coli at these stations were higher in September 2020 being over 1000 cfu/100mL compared to other months of monitoring.
Water quality monitoring results at station RP4 were noticeably different from the other three stations in which generally higher levels of salinity, turbidity, SS, nitrogen, phosphorus and COD were recorded, given its location at downstream experiencing estuarine and tidal influences. Significantly higher levels of turbidity, SS and E. coli were recorded in September 2020 likely related to the rainy weather recorded for the monitoring event.
When compared with the WQOs, water quality monitoring results complied with the WQOs throughout the baseline monitoring period, except for pH values (pH >9.0) at station RP4 recorded in May 2021.
Public Works Study Area
Water quality monitoring results were generally similar across stations PW1 and PW2 except that high level of E. coli was recorded at PW1 in January 2021. Water quality monitoring results at station PW3 showed significantly higher levels of COD exceeding the WQO of 30 mg/L for most of the measurements taken throughout baseline monitoring, likely due to the estuarine nature of this station. The levels of SS and E. coli recorded at PW3 were exceptionally high in September 2020 which were likely attributed to the heavy rain resulting strong stormwater runoff with suspended matters and contaminants at the station.
The water quality monitoring results for PW4, PW5 and PW6 exhibited overall similarities. However, it is worth noting that PW6 showed a notable high concentration of E. coli as recorded in September 2023 and November 2023 respectively, which might due to the runoff from the village houses in Ngau Au at distance about 200 m. The data summary and details of the cumulative water quality data for western tributary are listed in Appendix D8.2.
5.3
Action and Limit Levels and Event and Action Plan
According to Section 11.4.5 of the Updated EM&A Manual, Action and Limit Levels shall be established with reference to the baseline survey data, taking into account the species (taxa diversity or abundance) and season.
Owing to the mixed survey methods of the ecological monitoring resulting in both qualitative and quantitative data, evaluating the change in abundance quantitatively is considered not feasible. As such, taxa diversity (i.e. number of species) shall be adopted as the parameter for establishing the Action and Limit Levels.
As stipulated in the Updated EM&A Manual, the establishment of Action and Limit Levels shall refer to the taxa diversity of fish and aquatic invertebrate recorded in the corresponding wet and dry seasons. In addition, for effective evaluation of the monitoring result, only macroinvertebrates shall be accounted in the consideration of Action and Limit Levels.
On the other hand, as the EM&A program of TCW already has its own river water quality monitoring (i.e. 3 times per week, refer to Section 4 of this Baseline Monitoring Report) and associated Action and Limit Levels, therefore the ecologically-related water quality monitoring results (i.e. at monthly basis) during the construction phase will be adopted for facilitating the investigation in case of any trigger of Action and Limit Levels of ecological monitoring. The Action and Limit Levels of ecological monitoring are established below in Table 5.16.
Table 5.16: Action and Limit Levels for Ecological Monitoring during Construction Phase
|
Exceedance Level |
Description |
|
Action Level |
Reduction in the monthly taxa diversity (i.e. number of species) of fish or macroinvertebrates of any monitoring station compared to the corresponding monitoring season and station of the baseline survey by 30%. |
|
Limit Level |
Reduction in the monthly taxa diversity (i.e. number of species) of fish or macroinvertebrates of any monitoring station compared to the corresponding monitoring station and season of the baseline survey by 50%. |
For ease of reference, the average numbers (rounded to nearest 0.1) of macroinvertebrate and fish species at Wet Season (April to October) and Dry Season (November to March) at the respective monitoring stations are summarized below in Table 5.17 and Table 5.18 respectively.
Table 5.17: Average Number of Macroinvertebrate Species at Wet Season (April to October) & Dry Season (November to March) at the Aquatic Fauna Monitoring Stations
|
River Park Study Area |
Public Works Study Area |
|||||||||
|
|
RP1 |
RP2 |
RP3 |
RP4 |
PW1 |
PW2 |
PW3 |
PW4 |
PW5 |
PW6 |
|
Wet season |
3.0 |
1.7 |
1.9 |
2.9 |
1.3 |
4.0 |
2.3 |
3.3 |
3.0 |
5.7 |
|
Dry season |
2.2 |
1.8 |
1.0 |
3.6 |
2.0 |
3.7 |
0.7 |
3.3 |
3.3 |
2.7 |
Table 5.18: Average Number of Fish Species at Wet Season (April to October) & Dry Season (November to March) at the Aquatic Fauna Monitoring Stations
|
River Park Study Area |
Public Works Study Area |
|||||||||
|
RP1 |
RP2 |
RP3 |
RP4 |
PW1 |
PW2 |
PW3 |
PW4 |
PW5 |
PW6 |
|
|
Wet season |
5.1 |
5.0 |
1.3 |
7.1 |
4.0 |
1.3 |
6.3 |
6.3 |
5.3 |
5.0 |
|
Dry season |
5.8 |
5.0 |
0.2 |
6.2 |
6.7 |
0.7 |
6.0 |
6.0 |
4.3 |
6.3 |
As stipulated in the Section 11.4.5 of the Updated EM&A Manual, appropriate responses shall be carried out when triggering the Action and Limit Levels. An Event and Action Plan in Table 5.19 is established to investigate the cause, and if the cause is found to be project-related, remedial action shall be instigated to remove or reduce the source of disturbance.
Table 5.19: Event and Action Plan for Action and Limit Level Exceedance in Aquatic Fauna
|
Event |
Response |
|||
|
|
ET |
IEC |
ER |
Contractor |
|
1. Check monitoring data and confirm findings; 2. Investigate the cause of the reduction if it is related to construction works; 3. Immediately inform IEC, Contractor and ER; 4. Discuss mitigation measures with IEC, Contractor and ER; 5. Ensure mitigation measures are implemented. |
1. Check monitoring data, analysis and investigation by ET; 2. Review the proposed mitigation measures submitted by Contractor and advise the ER accordingly; 3. Review and advise the ET and ER on the effectiveness of the mitigation measures after implementation. |
1. Check the monitoring results and findings from ET and IEC; 2. Discuss with ET, IEC and Contractor on the proposed mitigation measures; 3. Supervise the implementation of the mitigation measures; 4. Discuss with ET, IEC and Contractor on the effectiveness of the implemented mitigation measures. |
1. Identify source(s) of impact; 2. Inform the ER and confirm notification of the non-compliance in writing; 3. Discuss with ET, IEC and ER and submit proposal of mitigation measures to ER and IEC; 4. Implement the agreed mitigation measures. 5. Instigate remedial action to remove or reduce source of disturbance if the cause is identified as project related. |
|
|
Limit Level Exceedance |
1. Check monitoring data and confirm findings; 2. Investigate the cause of the reduction if it is related to construction works; 3. Immediately inform IEC, Contractor and ER; 4. Discuss additional mitigation measures with IEC, Contractor and ER; 5. Ensure additional mitigation measures are implemented. |
1. Check monitoring data, analysis and investigation by ET; 2. Discuss with ET, Contractor and ER on the additional mitigation measures implemented; 3. Review the proposed additional mitigation measures submitted by Contractor and advise the ER accordingly; 4. Review and advise the ET and ER on the effectiveness of the additional mitigation measures implemented |
1. Check the monitoring results and findings from ET and IEC; 2. Discuss with ET, IEC and Contractor on the additional mitigation measures proposed; 3. Supervise the implementation of the additional mitigation measures; 4. Discuss with ET, IEC and Contractor on the effectiveness of the additional mitigation measures implemented. |
1. Identify source(s) of impact; 2. Inform the ER and confirm notification of the non-compliance in writing; 3. Discuss with ET, IEC and ER and submit proposal of additional mitigation measures to ER and IEC; 4. Implement the agreed additional mitigation measures. 5. Instigate additional remedial action to remove or reduce source of disturbance if the cause is identified as project related. |
5.4
References
Fellowes, J., M. Lau, D. Dudgeon, G.T. Reels, G.W.J., Ades, G. Carey, B. Chan, K. Roger, K.S. Lee M. Leven, K. Wilson and Y.T. Yu. 2002. Wild animals to watch: terrestrial and freshwater fauna of conservation concern in Hong Kong. Memoirs of the Hong Kong Natural History Society. 25:123-159.
IUCN. 2024. The IUCN Red List of Threatened Species. Version 2023-1. Retrieved 25 March, 2024 from https://www.iucnredlist.org/species/166016/6168828
Yue, P., and Chen, Y. 1998. China Red Data Book of Endangered Animals: Pisces. Science Press, Beijing. China. 256pp.
6
Landscape and Visual
6.1
Monitoring Requirement
According to the Updated EM&A Manual, the landscape and visual baseline will be determined with reference to the habitat maps included in the EIA Report and detailed tree survey to be completed before the works can commence as well as preliminary site conditions verification surveys. It is considered that site conditions verification surveys would be sufficient to represent the updated landscape and visual baseline for the Project. The surveys were conducted in July 2021 to verify if there is any major change to the landscape and visual conditions with reference to the approved EIA Report. Further details are presented in the following sections.
6.2
Monitoring
Methodology
Site condition verification surveys were conducted in July 2021 within 500m Study Area as shown in Appendix E1. In particular, the Landscape Resources (LRs) and Landscape Character Areas (LCAs) for the Project identified in Figure 11.2a-al and Figure 11.3a-ac of the approved EIA Report were reviewed, so that any major deviation from the landscape baseline condition as described in the approved EIA Report observed during the baseline monitoring could be noted and documented.
In addition, the Visual Sensitive Receivers (VSRs) of the Project identified in Figure 11.4a-aa of the approved EIA Report were reviewed before the baseline monitoring, so that any major deviation from the visual baseline condition as described in the approved EIA Report observed during the baseline monitoring could be noted and documented.
The key plans of LRs, LCAs and VSRs for the Project in the approved EIA Report are presented respectively in Appendix E2, Appendix E3 and Appendix E4 for reference.
6.3
Monitoring
Results
6.3.1
Landscape
Resources (LRs)
The identified LRs during the EIA stage include the followings and the detailed descriptions of the LRs were presented in the approved EIA Report:
LR1 – Secondary Woodland
LR2 – Shrubland and Grassland
LR3 – Transitional Waters
LR4 – Coastal Waters
LR5 – Watercourses
LR6 – Natural Shoreline
LR7 – Roads, Urban Infrastructure and Major Transport Corridor
LR8 – Village Type Development
LR9 – Urbanised Area
LR10 – Agricultural Land
LR11 – Plantation
LR12 – Mangroves
LR13 – Fung Shui Woodland
LR14 – Reedbed
LR15 – Artificial Seawall (1)
The site condition verification survey was conducted in July 2021 and these LRs were reviewed as far as practicable. During the site condition verification survey, no major change of landscape resource / element was identified. The updated baseline conditions of the LRs are presented in Appendix E5 for comparison.
6.3.2
Landscape
Character Areas (LCAs)
The identified LCAs during the EIA stage include the followings and the detailed descriptions of the LCAs were presented in the approved EIA Report:
LCA1 – Inshore Water Landscape (1)
LCA2 – Strait Landscape
LCA3 – Inter-tidal Coast Landscape
LCA4 – Coastal Upland and Hillside Landscape
LCA5 – Settled Valley Landscape
LCA6 – Upland and Hillside Landscape
LCA7a – Reclamation/ Ongoing Major Development Landscape (1)
LCA7b – Ongoing Major Comprehensive Urban Development Landscape (2)
LCA8 – Transportation Corridor Landscape
LCA9 – Mixed Modern Comprehensive Urban Development Landscape
LCA10a – Urban Peripheral Village Landscape
LCA10b – Miscellaneous Rural Fringe Landscape
LCA10c – Rural Township Landscape
LCA11 – Airport Landscape
LCA12 – Institutional Landscape
LCA13 – Residential Urban Landscape
The site condition verification survey was conducted in July 2021 and these LCAs were revisited as far as practicable. During the site condition verification survey, no major change of landscape character area / element was identified. The updated baseline conditions of the LCAs are presented in Appendix E6 for comparison.
Notes:
(1) LR15 – Artificial Seawall, LCA1 – Inshore Water Landscape and LCA7a – Reclamation/ Ongoing Major Development Landscape were not reviewed during the site condition verification survey since these LRs and LCA had been verified prior to the construction of TCE, and they are not relevant to the Project.
(2) LCA7b – Ongoing Major Comprehensive Urban Development Landscape identified at the EIA stage was recorded to have changed into LCA13 – Residential Urban Landscape during the site condition verification survey.
6.3.3
Visual
Sensitive Receivers (VSRs)
Photographs showing the updated views of the VSRs for the Project, as presented in the approved EIA Report, were taken in July 2021 from the same viewpoints, or nearby locations with similar views. Locations of these viewpoints are shown in Appendix E7. The updated baseline conditions are presented in Appendix E8 for comparison.
In general, the observed change of the baseline conditions when compared with those presented in the approved EIA Report are considered minor and do not significantly alter the overall landscape and visual baseline condition. Therefore, the assessment result of the landscape and visual impact assessment as presented in the approved EIA Report is considered valid. Additional landscape and visual mitigation measures, other than those recommended in the approved EIA Report, are thus not required.
Major differences observed between the baseline condition during the EIA stage and that during the site condition verification survey are illustrated below:
Southern Connection of Tuen Mun-Chek Lap Kok Link
During the EIA stage, it was assumed that the key construction elements (e.g. marine works) for the southern and northern connection of the Tuen Mun-Chek Lap Kok Link (TMCLKL) would be substantially completed by end of Year 2016. The updated baseline in July 2021 shows that the construction for the TMCLKL has been completed, which is in line with the prediction as presented in the approved EIA Report. As such, it does not affect the cumulative landscape and visual impact assessment results in the approved EIA Report.
Hong Kong-Zhuhai Macao Bridge Hong Kong Boundary Crossing Facilities
During the EIA stage, it was assumed that the key construction elements for Hong Kong Boundary Crossing Facilities (HKBCF) would be substantially completed by the end of Year 2016. The updated baseline in July 2021 shows that the construction for the HKBCF has been completed, which is in line with the prediction as presented in the approved EIA Report. As such, it does not affect the cumulative landscape and visual impact assessment results in the approved EIA Report.
Planned Residential Developments in the Existing Tung Chung New Town
During the EIA stage, it was assumed that the residential developments at Tung Chung Area 39 and Area 27 near the Project (LCA7b as stated in the approved EIA report) would be completed in 2018 and 2019. The updated baseline in July 2021 shows that these areas have been developed into Home Ownership Scheme (Yu Tai Court) and public (Mun Tung Estate) housings respectively (LCA13), which is in line with the prediction as presented in the approved EIA Report. As such, it does not affect the cumulative landscape and visual impact assessment results in the approved EIA Report.
6.3.4
Existing
Trees
Information on tree groups as presented in Appendix 11.1 of the approved EIA report was also reviewed. The results of an updated tree survey undertaken in mid-2020 within the Works Area will be used for update of the baseline condition of existing trees.
Relevant description of the baseline conditions of existing trees within the Works Area and their proposed treatment in the approved EIA Report (Register No.: AEIAR-205/2017) are summarised below.
The updated tree survey conducted in mid-2020 found that approximately 3,983 trees were located within Works Area for TCW project. Location of tree groups as presented in the approved EIA report and Works Area demarcated for TCW project are shown in Appendix E9.
Comparison of the broad-brush tree survey data as presented in the approved EIA report and recorded in the updated tree survey in mid-2020 was summarized in Table 6.1 and Appendix E10.
Table 6.1: Summary of Proposed Tree Treatment
|
|
Updated Tree Survey in mid-2020 |
Approved EIA Report |
|
No. of Trees to be Retained |
2,655 (46.6%) |
About 30% of the trees within the RODP boundary |
|
NL/2020/05 (Tree Group: TCB-1, WNU-1, WNU-2, WNU-3, WNU-4, WNU-5, WNU-6, WNU-7, WNU-8) |
586 |
|
|
NL/2020/06 (Tree Group: TCV-2, TCV-3, TCV-4, TCV-5, TCV-6, TCV-9, TCV-10, TCV-25, TCV-27, TCV-31, TCV-32, TCV-33, TCV-34, TCV-36, TCV-1) |
349 |
|
|
Contract 10 (Tree Group: TCB-5, TCB-6, TCB-7, TCB-9, TCB-10, TCB-11, TCB-12, WNU-9, TCV-7, TCV-8, TCV-12, TCV-14, TCV-15, TCV-17, TCV-18, TCV-20, TCV-21, TCV-23, TCV-24, TCV-25, TCV-26, TCV-27, TCV-28, TCV-29, TCV-35, WNU-8) |
To be provided(3) |
|
|
Contract 11 (Tree Group: TCV-16, TCV-20, TCV-22, TCV-23, TCV-30) |
To be provided(3) |
|
|
Outside TCW Works Area (Tree Group: TCB-2, TCB-3, TCB-4, TCB-8, WNU-3, FWSR-2, FWSR-3, FWSR-4, FWSR-5, FWSR-6, FWSR-7, TCV-11, TCV-13, TCV-19) |
1,720(2) |
|
|
No. of Trees to be Transplanted |
111 (1.9%) |
Almost 70% of trees within the RODP boundary |
|
NL/2020/05 |
62 |
|
|
NL/2020/06 |
49 |
|
|
Contract 10 |
To be provided(3) |
|
|
Contract 11 |
To be provided(3) |
|
|
Outside TCW Works Area |
0(4) |
|
|
No. of Trees to be Felled |
2,937 (51.5%) |
|
|
NL/2020/05 |
916 |
|
|
NL/2020/06 |
2,021 |
|
|
Contract 10 |
To be provided(3) |
|
|
Contract 11 |
To be provided(3) |
|
|
Outside TCW Works Area |
0(4) |
|
|
Total No. of Trees |
5,703 |
100% |
Notes:
(3) Details tree survey of Contract 10 and Contract 11 are to be conducted in later stage.
(4) Tree Groups TCB-2, TCB-3, TCB-4, TCB-8, WNU-3, FWSR-2, FWSR-3, FWSR-4, FWSR-5, FWSR-6, FWSR-7, TCV-11, TCV-13, TCV-19 are located outside TCW Works Area and will not be affected by TCW project, therefore, all trees from these tree groups are proposed to be retained. Estimated tree numbers are extracted from the approved EIA report as reference.
In general, the distribution of tree groups within the Works Area remained unchanged since the EIA stage. No newly planted tree groups were identified within the Works Area, while no tree groups identified at the EIA stage have been removed. Compared to the EIA stage, it was anticipated that more trees were proposed to be retained in the updated tree survey in mid-2020. Since tree groups namely TCB-2, TCB-3, TCB-4, TCB-8, WNU-3, FWSR-2, FWSR-3, FWSR-4, FWSR-5, FWSR-6, FWSR-7, TCV-11, TCV-13, TCV-19 were located outside TCW Works Area and will not be affected by TCW project, therefore, all trees from these tree groups are proposed to be retained.
Trees of Particular Interest
In the updated tree survey in mid-2020, a total of 24 nos. rare and precious species including 13 nos. of Aquilaria sinensis, 7 nos. Canthium dicoccum and 4 nos. Gmelina chinensis were recorded within the Works Area. No Registered Old & Valuable Tree (OVT), or stonewall trees were recorded throughout the tree survey. One potentially OVT, Ficus microcarpa, was identified within the Works Area. Details of the tree of particular interest was summarized in Table 6.2.
Table 6.2: Proposed Tree Treatment for the Trees of Particular Interest
|
Contract |
Species |
Tree ID |
Recommendation |
Remarks |
|
NL/2020/05
|
Aquilaria sinensis |
T8260, T8271, T8282, T8331, T8468 |
Fell |
Rare species; Poor tree form, health & structure; Not suitable for transplanting |
|
Canthium dicoccum |
T8217, T8231 |
Retain |
Rare species |
|
|
T8275, T8289, T8351 |
Fell |
Rare species; Poor tree form, health & structure; Not suitable for transplanting |
||
|
Gmelina chinensis |
T8259, T8262 |
Fell |
Rare species; Poor tree form, health & structure; Not suitable for transplanting |
|
|
NL/2020/06 |
Aquilaria sinensis |
T3537, T8685, T8996 |
Transplant |
Rare species |
|
T8509, T8690, T8835, T8998, T9006 |
Fell |
Rare species; Poor tree form, health & structure; Not suitable for transplanting |
||
|
Canthium dicoccum |
T8856, T8865 |
Fell |
Rare species; Poor tree form, health & structure; Not suitable for transplanting |
|
|
Gmelina chinensis |
T8557, T8936 |
Fell |
Rare species; Poor tree form, health & structure; Not suitable for transplanting |
|
|
Ficus microcarpa |
T192 |
Retain |
Potential OVT; DBH greater than 1000mm |
7 Conclusion
In accordance with the Updated EM&A Manual of the Project, baseline monitoring was undertaken prior to commencement of the construction works for the following baseline monitoring components:
● Air Quality;
● Noise;
● Water Quality;
● Ecology; and
● Landscape and Visual.
Baseline Air Quality Monitoring
Baseline air quality (dust) monitoring (1-hour TSP) was conducted at the two (2) designated monitoring locations (DM-5 and DM-6) from 9 to 17 July 2021 and from 21 to 25 July 2021. Monitoring was suspended on 18, 19 and 20 July 2021 due to a tropical cyclone. Overall, the baseline air quality results are considered representative to the ambient air quality of the sensitive receivers in the vicinity of the Project and were used to establish the Action and Limit Levels for air quality (1-hour TSP levels).
Baseline Noise Monitoring
Baseline noise monitoring was carried out at the five (5) designated monitoring locations (NMS-CA-5, NMS-CA-6, NMS-CA-7, NMS-CA-8 and NMS-CA-9). Monitoring was conducted at NMS-CA-5 and NMS-CA-6 from 10 to 17 July 2021 and from 20 to 27 July 2021, at NMS-CA-7 from 16 to 18 August 2021 and from 19 to 31 August 2021, and at NMS-CA-8 and NMS-CA-9 from 9 to 17 July 2021 and from 20 to 26 July 2021. Due to a tropical cyclone, monitoring at NMS-CA-5, NMS-CA-6, NMS-CA-8 and NMS-CA-9 was suspended on 17 July 2021 at 19:00 and resumed on 20 July 2021 at 23:00. Also, due to rainstorm, monitoring at NMS-CA-7 was suspended on 18 August 2021 at 23:00 and resumed on 19 August 2021 at 23:00.
The major noise sources identified at the respective monitoring stations were:
● dog barking and bird chirping at NMS-CA-5;
● traffic noise, dog barking and bird chirping at NMS-CA-6;
● traffic noise, dog barking, bird chirping and excavator operating nearby at NMS-CA-7; and
● traffic noise at NMS-CA-8 and NMS-CA-9.
The baseline monitoring results are considered representative of the ambient noise levels of the sensitive receivers in the vicinity of the Project.
Baseline Water Quality Monitoring
Baseline water quality monitoring was conducted at the seven (7) designated monitoring stations presented in Table 2.5 of the Baseline Monitoring Proposal for Construction Phase Water Quality (TCW-WQM1, TCW-WQM2, TCW-WQM3A, TCW-WQM4, TCW-WQM5A, TCW-WQM6 and TCW-WQM7). Monitoring was conducted from 9 August 2021 to 3 September 2021. No observable pollution source was recorded at the monitoring stations, however the baseline monitoring results are found to be inadequate to represent the natural variations in ambient water quality levels. Therefore, it was considered prudent to incorporate additional baseline data to establish the Action and Limit Levels for SS and Turbidity.
For supplementing Tung Chung Stream (West) (i.e. TCW-WQM2, TCW-WQM4 and TCW-WQM6) stations, and Tung Chung Stream (East) (i.e. TCW-WQM3A, TCW-WQM5A and TCW-WQM7) stations, EPD’s routine river water quality monitoring at Tung Chung River (TC1 at Tung Chung Stream West and TC2 at Tung Chung Stream East respectively) was used to supplement the baseline data for SS and Turbidity. For TCW-WQM1, no EPD routine marine water quality monitoring station at Tung Chung Bay is available, hence a supplementary 4-week baseline monitoring was carried out at TCW-WQM1 in October to November 2021 to extend the baseline monitoring dataset for deriving the Action and Limit Levels at TCW-WQM1.
Notwithstanding the above, the baseline conditions will be reviewed regularly and updated as appropriate, to demonstrate the continued suitability of the impact and control monitoring.
Baseline Ecological Monitoring
Baseline ecological and water quality monitoring next to the Eastern Tributary of Tung Chung Stream of TCW was conducted from 21 August 2020 to 14 July 2021 on a monthly basis at four (4) stations in River Park Study Area (RP1, RP2, RP3, RP4) for 12 months and three (3) stations in Public Works area (PW1, PW2, PW3) for 6 months covering wet season, as presented in Section 2.2 of the Detailed Ecological and Water Quality Monitoring Plan prepared by the Environmental Team of Tung Chung New Town Extension (East) ("TCE ET"). On the other hand, baseline ecological and water quality monitoring next to the Western Tributary of Tung Chung Stream of TCW was conducted from 18 May 2023 to 12 March 2024 on a bi-monthly basis at three (3) stations in Public Works area (PW4, PW5 and PW6) for 6 months covering wet season, as presented in Section 2.2 of the Monitoring Proposal prepared by the TCW ET.
As presented in the Ecological and Water Quality Final Monitoring Report prepared by the TCE ET, for ecological monitoring, a total of 20 aquatic invertebrate and 28 fish species were recorded, among which one (1) aquatic invertebrate and three (3) fish species of conservation importance were recorded. For water quality monitoring, monitoring results are generally similar across the stations, except two (2) of which are located at the proximity of the estuary, showing higher levels in certain parameters due to the estuarine environment and tidal influence. On the other hand, the baseline ecological monitoring results at the Western Tributary of Tung Chung Stream indicated that a total of 24 aquatic invertebrate and 18 fish species were recorded, among which one (1) aquatic invertebrate and four (4) fish species of conservation importance were recorded. For water quality monitoring, monitoring results are generally similar across the stations except one (1) showed notable high concentration of E. coli which might due to the runoff from the village houses in Ngau Au at distance about 200 m.
Action and Limit Levels were established for taxa diversity, i.e. number of species, of fish and macroinvertebrate based on the baseline monitoring results. An Event and Action Plan was also proposed for exceedance of the Action and Limit Levels.
Baseline Landscape and Visual Monitoring
Baseline landscape and visual monitoring was carried out in July 2021 to review the identified Landscape Resources, Landscape Character Areas and Visually Sensitive Receivers in the approved EIA report.
In general, the landscape and visual baseline conditions remain similar as that identified in the approved EIA report, except Ongoing Major Comprehensive Urban Development Landscape (LCA7b) identified at the EIA stage was recorded to have changed into Residential Urban Landscape (LCA13).
In addition, the distribution of tree groups within the Works Area remained unchanged since the EIA stage. No newly planted tree groups were identified within the Works Area, while no tree groups identified at the EIA stage have been removed.
Overall, there is no major change in the landscape and visual baseline conditions comparing to those during the EIA stage. Therefore, no additional landscape and visual mitigation measures other than those recommended in the approved EIA Report are required.