|
Expansion of Hong Kong International Airport into a Three-Runway System |
|
Construction Phase Monthly EM&A Report No.20 (For August 2017) |
Contents
The “Expansion of Hong Kong International
Airport into a Three-Runway System” (the Project) serves to meet the future air
traffic demands at Hong Kong International Airport (HKIA). On 7 November
2014, the Environmental Impact Assessment (EIA) Report (Register No.:
AEIAR-185/2014) for the Project was approved and an Environmental Permit (EP)
(Permit No.: EP-489/2014) was issued for the construction and operation of the
Project.
Airport Authority Hong Kong (AAHK)
commissioned Mott MacDonald Hong Kong Limited (MMHK) to undertake the role of
Environmental Team (ET) for carrying out the Environmental Monitoring &
Audit (EM&A) works during the construction phase of the Project in
accordance with the Updated EM&A Manual (the Manual).
This is the 20th
Construction Phase Monthly EM&A Report for the Project which summarizes the
monitoring results and audit findings of the EM&A programme during the
reporting period from 1 to 31 August 2017.
Key Activities in the Reporting Period
The key activities of the Project carried out in the reporting period included deep
cement mixing (DCM) works, laying of sand blanket, site office establishment,
horizontal directional drilling (HDD) works, concrete removal works, piling and
excavation works.
EM&A
Activities Conducted in the Reporting Period
The monthly EM&A
programme was undertaken in accordance with the Manual of the Project. During
the reporting period, the
ET conducted 36 sets of construction dust measurements, 25 sets of construction
noise measurements, 14 events of water quality measurements, 1 round of
terrestrial ecology monitoring on Sheung Sha Chau Island, 2 complete sets of small vessel line-transect surveys and 5
days of land-based theodolite tracking survey effort for Chinese White Dolphin
(CWD) monitoring and waste monitoring.
Weekly site inspections of the
construction works were carried out by the ET to audit the implementation of
proper environmental pollution control and mitigation measures for the Project.
Bi-weekly site inspections were also conducted by the Independent Environmental
Checker (IEC). Observations have been recorded in the site inspection
checklists and provided to the contractors together with the appropriate
follow-up actions where necessary.
On the implementation of
Marine Mammal Watching Plan (MMWP), dolphin observers were deployed by the
contractors for laying of open sea silt curtain and laying of silt curtains for
sand blanket in accordance with the plan. On the implementation of Dolphin
Exclusion Zone (DEZ) Plan, dolphin observers at 12 to 16 dolphin observation
stations were deployed for continuous monitoring of the DEZ by all contractors
for DCM works in accordance with the DEZ Plan. Trainings for the proposed
dolphin observers were provided by the ET prior to the aforementioned works,
with the training records kept by the ET. From the contractors’ MMWP
observation records and DEZ monitoring records, no dolphin or other marine
mammals were observed within or around the silt curtains, whilst there was one
record of dolphin sighting within the DEZ of DCM works in this reporting
period. Audits of acoustic decoupling for construction vessels were also
carried out by the ET.
On the implementation of the Marine
Travel Routes and Management Plan for High Speed Ferries of SkyPier
(the SkyPier Plan), the daily movements of all SkyPier high speed ferries (HSFs) in August 2017 were in
the range of 11 to 91 daily movements, which are within the maximum daily cap
of 125 daily movements. A total of 744 HSF movements under the SkyPier Plan were recorded in the reporting period. All
HSFs had travelled through the Speed Control Zone (SCZ) with average speeds
under 15 knots (9.7 to 14.0 knots), which were in compliance with the SkyPier Plan. One ferry movement with minor deviation from
the diverted route is under investigation by ET. The investigation result will
be presented in the next monthly EM&A report. In summary, the ET and IEC
have audited the HSF movements against the SkyPier
Plan and conducted follow up investigation or actions accordingly.
On the implementation of the Marine
Travel Routes and Management Plan for Construction and Associated Vessel
(MTRMP-CAV), the Marine Surveillance System (MSS) automatically recorded the
deviation case such as speeding, entering no entry zone, not traveling through
the designated gate. ET conducted checking to ensure the MSS records all
deviation cases accurately. Training has been provided for the concerned
skippers to facilitate them in familiarising with the requirements of the
MTRMP-CAV. Deviations including speeding in the works area, entry from
non-designated gates, and entering no-entry zones were reviewed by ET. All the
concerned captains were reminded by the contractor’s Marine Traffic Control
Centre (MTCC) representative to comply with the requirements of the MTRMP-CAV.
ET reminded contractors that all vessels shall avoid entering the no-entry zone, in particular the Brothers Marine Park. 3-month
rolling programmes for construction vessel activities, which ensures the
proposed vessels are necessary and minimal through good planning, were also
received from contractors.
Results of Impact Monitoring
The monitoring works for
construction dust, construction noise, water quality, construction waste,
terrestrial ecology, and CWD were conducted during the reporting period in
accordance with the Manual.
No exceedance of the Action or Limit
Levels in relation to construction dust, construction noise, construction
waste, and CWD monitoring was recorded in the reporting period.
The water quality monitoring results
for total alkalinity and chromium obtained during the reporting period did not
trigger their corresponding Action and Limit Levels stipulated in the EM&A
programme for triggering the relevant investigation and follow-up procedures
under the programme if being exceeded. For DO, turbidity, SS, and nickel, some
of the testing results exceeded the relevant Action or Limit Levels, and the
corresponding investigations were conducted accordingly. The investigation
findings concluded that the exceedances were not due to the Project.
The monthly terrestrial ecology
monitoring on Sheung Sha Chau observed that HDD works were conducted at the
daylighting location and there was no encroachment upon the egretry
area nor any significant disturbance to the egrets foraging at Sheung Sha Chau
by the works.
Summary of Upcoming Key Issues
Key activities anticipated in the
next reporting period of the Project include the following:
Advanced
Works:
Contract
P560 (R) Aviation Fuel Pipeline Diversion Works
● HDD works; and
● Stockpiling of excavated
materials from HDD operation.
DCM Works:
Contract 3201 to 3205 DCM Works
● Laying of sand blanket
and geotextile; and
● DCM works.
Reclamation Works:
Contract 3206 Main Reclamation Works
● Laying of sand blanket.
Airfield
Works:
Contract 3301 North Runway Crossover Taxiway
● CLP cable ducting work.
Terminal 2 Expansion Works:
Contract 3501 Antenna Farm and Sewage Pumping Station
● Excavation and piling
works.
Contract 3502 Terminal 2 Automated People Mover (APM) Depot Modification
Works
● Removal of existing
concrete.
The
key environmental
issues will be associated with construction dust, construction noise, water
quality, construction waste management, CWD and terrestrial ecology on Sheung
Sha Chau. The implementation of required mitigation measures by the contractor
will be monitored by the ET.
|
|
|
|
|
DEZ Monitoring for DCM Works by Contractor |
Chemical Spill Drill conducted by the Contractor |
Dolphin Observer Training |
Summary
Table
The
following table summarizes the key findings of the EM&A programme during
the reporting period:
|
|
Yes |
No |
Details |
Analysis / Recommendation / Remedial Actions |
|
Exceedance of Limit Level^ |
|
ü |
No exceedance of project-related limit level was recorded. |
Nil |
|
Exceedance of Action Level^ |
|
ü |
No exceedance of project-related action level was recorded. |
Nil |
|
Complaints Received |
ü |
|
A complaint on sand filling materials was received on 8 Aug 2017. |
Investigation details of the complaint is presented in S7.8.1. |
|
Notification of any summons and status of prosecutions |
|
ü |
No notifications of summons or prosecution were received. |
Nil |
|
Changes that affect the EM&A |
|
ü |
There were no changes to the construction works that may affect the EM&A |
Nil |
Remark: ^Only
exceedance of Action or Limit Level related to Project works is counted as
Breaches of Action or Limit Level.
1 Introduction
1.1
Background
On 7 November 2014, the
Environmental Impact Assessment (EIA) Report (Register No.: AEIAR-185/2014) for
the “Expansion of Hong Kong International Airport into a Three-Runway System”
(the Project) was approved and an Environmental Permit (EP) (Permit No.:
EP-489/2014) was issued for the construction and operation of the Project.
Airport Authority Hong Kong (AAHK)
commissioned Mott MacDonald Hong Kong Limited (MMHK) to undertake the role of
Environmental Team (ET) for carrying out the Environmental Monitoring &
Audit (EM&A) works during the construction phase of the Project in
accordance with the Updated EM&A Manual (the Manual) submitted under EP
Condition 3.1. The Manual is available on the Project’s dedicated website
(accessible at: http://env.threerunwaysystem.com/en/index.html).
AECOM Asia Company Limited (AECOM) was employed by AAHK as the
Independent Environmental Checker (IEC) for the Project.
The Project covers the expansion of
the existing airport into a three-runway system (3RS) with key project
components comprising land formation of about 650 ha and all associated
facilities and infrastructure including taxiways, aprons, aircraft stands, a passenger
concourse, an expanded Terminal 2, all related airside and landside works and
associated ancillary and supporting facilities. The existing submarine aviation
fuel pipelines and submarine power cables also require diversion as part of the
works.
Construction of the Project is to
proceed in the general order of diversion of the submarine aviation fuel
pipelines, diversion of the submarine power cables, land formation, and
construction of infrastructure, followed by construction of superstructures.
The updated overall phasing
programme of all construction works was presented in Appendix A of the
Construction Phase Monthly EM&A Report No. 7 and the contract information
was presented in Appendix A.
1.2
Scope
of this Report
This is the 20th
Construction Phase Monthly EM&A Report for the Project which summarizes the
key findings of the EM&A programme during the reporting period from 1 to 31
August 2017.
1.3
Project
Organisation
The Project’s organization structure
presented in Appendix B of the Construction Phase Monthly EM&A Report No.1
remained unchanged during the reporting period. Contact details of the key
personnel have been updated and is presented in Table 1.1.
Table
1.1: Contact
Information of Key Personnel
|
Party |
Position |
Name |
Telephone |
|
Project Manager’s Representative (Airport Authority Hong Kong) |
Principal Manager, Environment |
Lawrence Tsui |
2183 2734 |
|
Environmental Team (ET) (Mott MacDonald Hong Kong Limited) |
Environmental Team Leader |
Terence Kong |
2828 5919 |
|
|
Deputy Environmental Team Leader |
Heidi Yu |
2828 5704 |
|
|
Deputy Environmental Team Leader |
Keith Chau |
2972 1721 |
|
Independent Environmental Checker (IEC) (AECOM Asia Company Limited) |
Independent Environmental Checker |
Jackel Law |
3922 9376
|
|
|
Deputy Independent Environmental Checker |
Roy Man |
3922 9376 |
|
Advanced Works: |
|
|
|
|
Contract P560(R) Aviation Fuel Pipeline Diversion Works (Langfang Huayuan Mechanical and Electrical Engineering Co., Ltd.) |
Project Manager
|
Wei Shih
|
2117 0566
|
|
|
Environmental Officer |
Lyn Liu
|
5172 6543
|
|
DCM Works: |
|
|
|
|
Contract 3201 DCM (Package 1) (Penta-Ocean-China State-Dong-Ah Joint Venture) |
Project Director
|
Tsugunari Suzuki
|
9178 9689 |
|
|
Environmental Officer
|
Alan Tam
|
6119 3107 |
|
Contract 3202 DCM (Package 2) (Samsung-BuildKing Joint Venture) |
Project Manager |
Ilkwon Nam
|
9643 3117 |
|
|
Environmental Officer
|
Dickson Mak
|
9525 8408 |
|
Contract 3203 DCM (Package 3) (Sambo E&C Co., Ltd) |
Project Manager
|
Eric Kan
|
9014 6758 |
|
|
Environmental Officer
|
David Hung
|
9765 6151 |
|
Contract 3204 DCM (Package 4) (CRBC-SAMBO Joint Venture) |
Project Manager |
Kyung-Sik Yoo
|
9683 8697
|
|
|
Environmental Officer |
Kanny Cho |
6799 8226 |
|
Contract 3205 DCM (Package 5) (Bachy Soletanche - Sambo Joint Venture) |
Deputy Project Director |
Min Park |
9683 0765 |
|
|
Environmental Officer |
Margaret Chung |
9130 3696 |
|
Reclamation Works: |
|
|
|
|
Contract 3206 (ZHEC-CCCC-CDC Joint Venture) |
Project Manager |
Kim Chuan Lim
|
3693 2288 |
|
|
Environmental Officer |
Kwai Fung Wong |
3693 2252 |
|
Terminal 2 Expansion Works: |
|
|
|
|
Contract 3501 Antenna Farm and Sewage Pumping Station (Build King Construction Ltd.) |
Project Manager
|
Osbert Sit
|
9079 7030
|
|
|
Environmental Officer |
Kelvin Cheung |
9305 6081 |
|
Contract 3502 Terminal 2 APM Depot Modification Works (Build King Construction Ltd.) |
Project Manager |
Kivin Cheng |
9380 3635 |
|
|
Environmental Officer |
Chun Pong Chan |
9187 7118 |
1.4 Summary of Construction Works
The key activities of the Project carried out in the reporting period
included DCM works, laying of sand blanket, site office establishment, HDD
works, concrete removal works, piling and excavation works.
1.5
Summary
of EM&A Programme Requirements
The status
for all environmental aspects is presented in Table 1.2. The EM&A requirements
remained unchanged during the reporting period and details can be referred to
Table 1.2 of the Construction Phase Monthly EM&A Report No. 1.
Table 1.2: Summary of status for all
environmental aspects under the Updated EM&A
Manual
|
Parameters |
Status |
|
Air Quality |
|
|
Baseline Monitoring |
The baseline air quality monitoring result has been reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4. |
|
Impact Monitoring |
On-going |
|
Noise |
|
|
Baseline Monitoring |
The baseline noise monitoring result has been reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4. |
|
Impact Monitoring |
On-going |
|
Water Quality |
|
|
General Baseline Water Quality Monitoring for reclamation, water jetting and field joint works |
The baseline water quality monitoring result has been reported in Baseline Water Quality Monitoring Report and submitted to EPD under EP Condition 3.4. |
|
General Impact Water Quality Monitoring for reclamation, water jetting and field joint works |
On-going |
|
Initial Intensive Deep Cement Mixing (DCM) Water Quality Monitoring |
Completed in May 2017 and data analysis in-progress. |
|
Early/ Regular DCM Water Quality Monitoring |
On-going |
|
Waste Management |
|
|
Waste Monitoring |
On-going |
|
Land Contamination |
|
|
Supplementary Contamination Assessment Plan (CAP) |
To be submitted with the relevant construction works. |
|
Contamination Assessment Report (CAR) for Golf Course |
The CAR for Golf Course was submitted to EPD. |
|
Terrestrial Ecology |
|
|
Pre-construction Egretry Survey Plan |
The Egretry Survey Plan was submitted and approved by EPD under EP Condition 2.14. |
|
Ecological Monitoring |
The ecological monitoring was resumed since August 2017. |
|
Marine Ecology |
|
|
Pre-Construction Phase Coral Dive Survey |
The Coral Translocation Plan was submitted and approved by EPD under EP Condition 2.12. |
|
Coral Translocation |
The coral translocation was completed. |
|
Post-Translocation Coral Monitoring |
On-going |
|
Chinese White Dolphins (CWD) |
|
|
Vessel Survey, Land-based Theodolite Tracking and Passive Acoustic Monitoring (PAM) |
|
|
Baseline Monitoring |
Baseline CWD results were reported in the CWD Baseline Monitoring Report and submitted to EPD in accordance with EP Condition 3.4. |
|
Impact Monitoring |
On-going |
|
Landscape & Visual |
|
|
Baseline Monitoring |
The baseline landscape & visual monitoring result has been reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.4. |
|
Impact Monitoring |
On-going |
|
Environmental Auditing |
|
|
Regular site inspection |
On-going |
|
Marine Mammal Watching Plan (MMWP) implementation measures |
On-going |
|
Dolphin Exclusion Zone Plan (DEZP) implementation measures |
On-going |
|
SkyPier High Speed Ferries (HSF) implementation measures |
On-going |
|
Construction and Associated Vessels Implementation measures |
On-going |
|
Complaint Hotline and Email channel |
On-going |
|
Environmental Log Book |
On-going |
Taking into account the construction
works in this reporting period, impact monitoring of air quality, noise, water
quality, waste management, ecology, landscape & visual and CWD were carried
out in the reporting period.
The EM&A programme also involved
weekly site inspections and related auditing conducted by the ET for checking
the implementation of the required environmental mitigation measures
recommended in the approved EIA Report. In order to enhance environmental
awareness and closely monitor the environmental performance of the contractors,
environmental briefings and regular environmental management meetings were
conducted.
The EM&A programme has been
following the recommendations presented in the approved EIA Report and the
Manual. A summary of implementation status of the environmental mitigation
measures for the construction phase of the Project during the reporting period
is provided in Appendix B.
2
Air Quality Monitoring
2.1
Monitoring
Stations
Air quality monitoring was conducted
at 2 representative monitoring stations in the vicinity of air sensitive receivers
in Tung Chung and villages in North Lantau in accordance with the Manual. Table 2.1 describes
the details of the monitoring stations. Figure 2.1 shows the
locations of the monitoring stations.
Table 2.1: Locations of Impact Air
Quality Monitoring Stations
|
Monitoring Station |
Location |
|
AR1A |
Man Tung Road Park |
|
AR2 |
Village House at Tin Sum |
2.2 Monitoring Requirements and Schedule
In accordance with the Manual,
baseline 1-hour total suspended particulate (TSP) levels at the two air quality
monitoring stations were established as presented in the Baseline Monitoring
Report. Impact 1-hour TSP monitoring was conducted for three times every 6
days. The Action and Limit Levels of the air quality monitoring stipulated in
the EM&A programme for triggering the relevant investigation and follow-up
procedures under the programme are provided in Table 2.2.
The air quality monitoring schedule
involved in the reporting period is provided in Appendix C.
Table 2.2: Action and Limit Levels
for 1-hour TSP
|
Monitoring Station |
Action Level (mg/m3) |
Limit Level (mg/m3) |
|
AR1A |
306 |
500 |
|
AR2 |
298 |
2.3
Monitoring
Equipment
Portable direct reading dust meter
was used to carry out the 1-hour TSP monitoring. Details of equipment are given
in Table 2.3.
Table 2.3: Air Quality Monitoring
Equipment
|
Equipment |
Brand and Model |
Last Calibration Date |
|
Portable direct reading dust meter (Laser dust monitor) |
SIBATA LD-3B-001 (Serial No. 934393) |
26 Oct 2016 |
|
|
SIBATA LD-3B-002 (Serial No. 974350) |
26 Oct 2016 |
|
|
SIBATA LD-3B-003 (Serial No. 276018) |
26 Oct 2016 |
2.4 Monitoring Methodology
2.4.1 Measuring Procedure
The
measurement procedures involved in the impact 1-hr TSP monitoring can be
summarised as follows:
a.
The portable direct
reading dust meter was mounted on a tripod at a height of 1.2 m above the
ground.
b.
Prior to the
measurement, the equipment was set up for 1 minute span check and 6 second
background check.
c.
The one hour dust
measurement was started. Site conditions and dust sources at the nearby area
were recorded on a record sheet.
d.
When the measurement
completed, the “Count” reading per hour was recorded for result calculation.
2.4.2 Maintenance and Calibration
The
portable direct reading dust meter is calibrated every year against high volume
sampler (HVS) to check the validity and accuracy of the results measured by
direct reading method. The calibration certificates of the portable direct
reading dust meter and calibration record of the HVS provided in Appendix B of
the Construction Phase Monthly EM&A Report No.11 are still valid. The
calibration certificates for portable direct reading dust meter are updated and
provided in Appendix E.
2.5
Analysis
and Interpretation of Monitoring Results
The monitoring
results for 1-hour TSP are summarized in Table
2.4. Detailed impact monitoring results are presented in Appendix D.
Table 2.4: Summary of 1-hour TSP
Monitoring Results
|
Monitoring Station |
1-hr TSP Concentration Range (mg/m3) |
Action Level (mg/m3) |
Limit Level (mg/m3) |
|
AR1A |
8 – 28 |
306 |
500 |
|
AR2 |
22 – 46 |
298 |
No exceedance of the Action or Limit
Level was recorded at all monitoring stations in the reporting period.
General meteorological conditions
throughout the impact monitoring period were recorded. Wind data including wind
speed and wind direction for each monitoring day were collected from the Chek Lap Kok Wind Station.
3 Noise Monitoring
3.1
Monitoring
Stations
Noise monitoring was conducted at 5
representative monitoring stations in the vicinity of noise sensitive receivers
in Tung Chung and villages in North Lantau in accordance with the Manual. Figure 2.1 shows the
locations of the monitoring stations and these are described in Table 3.1 below. As described in Section
4.3.3 of the Manual, monitoring at NM2 will commence when the future
residential buildings in Tung Chung West Development become occupied.
Table 3.1:
Locations of Impact Noise Monitoring Stations
|
Monitoring Station |
Location |
Type of measurement |
|
NM1A |
Man Tung Road Park |
Free field |
|
NM2(1) |
Tung Chung West Development |
To be determined |
|
NM3A |
Site Office |
Facade |
|
NM4 |
Ching Chung Hau Po Woon Primary School |
Free field |
|
NM5 |
Village House in Tin Sum |
Free field |
|
NM6 |
House No. 1, Sha Lo Wan |
Free field |
Note: (1) As
described in Section 4.3.3 of the Manual, noise monitoring at NM2 will only
commence after occupation of the future Tung Chung West Development.
3.2
Monitoring
Requirements and Schedule
In accordance with the Manual, baseline noise levels at the noise
monitoring stations were established as presented in the Baseline Monitoring
Report. Impact noise monitoring was conducted once per week in the form of 30-minute
measurements of Leq, L10 and L90
levels recorded at each monitoring station between 0700 and 1900 on normal
weekdays. The Action and Limit Levels of the noise monitoring stipulated in the
EM&A programme for triggering the relevant investigation and follow-up
procedures under the programme are provided in Table 3.2. The construction noise monitoring
schedule involved in the reporting period is provided in Appendix C.
Table 3.2: Action and Limit Levels
for Construction Noise
|
Monitoring Stations |
Time Period |
Action Level |
Limit Level, Leq(30mins) dB(A) |
|
NM1A, NM2, NM3A, NM4, NM5 and NM6 |
0700-1900 hours on normal weekdays |
When one documented complaint is received from any one of the sensitive receivers |
75 dB(A)(i) |
Note: (i)
Reduced to 70dB(A) for school and 65dB(A) during school examination periods.
3.3
Monitoring Equipment
Noise monitoring was performed using
sound level meter at each designated monitoring station. The sound level
meters deployed comply with the International Electrotechnical Commission
Publications 651:1979 (Type 1) and 804:1985 (Type 1) specifications.
Acoustic calibrator was used to check the sound level meters by a known sound
pressure level for field measurement. Details of equipment are given in Table 3.3.
Table 3.3:
Noise Monitoring Equipment
|
Equipment |
Brand and Model |
Last Calibration Date |
|
|
Integrated Sound Level Meter |
B&K 2238 (Serial No. 2800932) |
17 Jul 2017 |
|
|
B&K 2238 (Serial No. 2381580) |
8 Sep 2016 |
||
|
|
|||
|
Acoustic Calibrator |
B&K 4231 (Serial No. 3003246) |
16 May 2017 |
|
|
B&K 4231 (Serial No. 3004068) |
17 Jul 2017 |
||
3.4 Monitoring Methodology
3.4.1 Monitoring Procedure
The
monitoring procedures involved in the noise impact monitoring can be summarised
as follows:
a. The sound level meter was set on a tripod at
least a height of 1.2 m above the ground for free-field measurements at
monitoring stations NM1A, NM4, NM5 and NM6. A correction of +3 dB(A) was
applied to the free field measurements.
b. Façade measurements were made at the monitoring
station NM3A.
c. Parameters such as frequency weighting, time
weighting and measurement time were set.
d. Prior to and after each noise measurement, the
meter was calibrated using the acoustic calibrator. 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.
e. During the monitoring period, Leq, L10 and L90 were
recorded. In addition, site conditions and noise sources were recorded on
a record sheet.
f. Noise measurement results were
corrected with reference to the baseline monitoring levels.
g. Observations were recorded when high intrusive
noise (e.g. dog barking, helicopter noise) was observed during the monitoring.
3.4.2 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 laboratory accredited under Hong Kong Laboratory Accreditation Scheme
(HOKLAS) to check and calibrate at yearly intervals.
Calibration certificates of the
sound level meters and acoustic calibrators used in the noise monitoring
provided in Appendix B of the Construction Phase Monthly EM&A Report No. 9,
Appendix D of the Construction Phase Monthly EM&A Report No. 17, and
Appendix E of the Construction Phase Monthly EM&A Report No. 19 are still
valid.
3.5
Analysis
and Interpretation of Monitoring Results
The construction noise monitoring results are
summarized in Table 3.4 and the detailed monitoring data are provided
in Appendix D.
Table 3.4: Summary of Construction
Noise Monitoring Results
|
Monitoring Station |
Noise Level Range, dB(A) Leq (30 mins) |
Limit Level, dB(A) Leq (30 mins) |
|
NM1A(i) |
70 – 72 |
75 |
|
NM3A |
61 – 63 |
75 |
|
NM4(i) |
60 – 65 |
70(ii) |
|
NM5(i) |
53 – 61 |
75 |
|
NM6(i) |
68 – 73 |
75 |
Notes: (i) +3 dB(A) Façade correction included;
(ii) Reduced to 65 dB(A) during school examination periods at NM4. No school
examination took place in the reporting period.
As the construction activities were
far away from the monitoring stations, major sources of noise dominating the
monitoring stations observed during the construction noise impact monitoring
were road traffic noise at NM1A, helicopter and aircraft noise at NM3A,
helicopter noise and construction noise from nearby school at NM4, aircraft,
helicopter, and dog barking noise at NM5, and insect, aircraft, helicopter, and
marine vessel noise at NM6 in this reporting period.
No exceedance of the Action or Limit
Level was recorded at all monitoring stations in the reporting period.
4
Water Quality Monitoring
4.1
Monitoring
Stations
Water
quality monitoring was conducted at a total of 22 water quality monitoring
stations, comprising 12 impact (IM) stations, 7 sensitive receiver (SR)
stations and 3 control stations in the vicinity of water quality sensitive
receivers around the airport island in accordance with the Manual. Table 4.1 describes the details of the
monitoring stations. Figure 3.1 shows the
locations of the monitoring stations.
Table 4.1: Monitoring Locations and Parameters for Impact Water Quality
Monitoring
|
Monitoring |
Description |
Coordinates |
Parameters |
|
|
Station |
|
Easting |
Northing |
|
|
C1 |
Control |
804247 |
815620 |
DO, pH, Temperature, Salinity, Turbidity, SS, Total Alkalinity, Heavy Metals(2) |
|
C2 |
Control |
806945 |
825682 |
|
|
C3(3) |
Control |
817803 |
822109 |
|
|
IM1 |
Impact |
806458 |
818351 |
|
|
IM2 |
Impact |
806193 |
818852 |
|
|
IM3 |
Impact |
806019 |
819411 |
|
|
IM4 |
Impact |
805039 |
819570 |
|
|
IM5 |
Impact |
804924 |
820564 |
|
|
IM6 |
Impact |
805828 |
821060 |
|
|
IM7 |
Impact |
806835 |
821349 |
|
|
IM8 |
Impact |
807838 |
821695 |
|
|
IM9 |
Impact |
808811 |
822094 |
|
|
IM10 |
Impact |
809838 |
822240 |
|
|
IM11 |
Impact |
810545 |
821501 |
|
|
IM12 |
Impact |
811519 |
821162 |
|
|
SR1(1) |
Future Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities (HKBCF) Seawater Intake for cooling |
812586 |
820069 |
DO, pH, Temperature, Salinity, Turbidity, SS
|
|
SR2(3) |
Planned marine park / hard corals at The Brothers / Tai Mo To |
814166 |
821463 |
|
|
SR3 |
Sha Chau and Lung Kwu Chau Marine Park / fishing and spawning grounds in North Lantau |
807571 |
822147 |
|
|
SR4A |
Sha Lo Wan |
807810 |
817189 |
|
|
SR5A |
San Tau Beach SSSI |
810696 |
816593 |
|
|
SR6 |
Tai Ho Bay, Near Tai Ho Stream SSSI |
814663 |
817899 |
|
|
SR7 |
Ma Wan Fish Culture Zone (FCZ) |
823742 |
823636 |
|
|
SR8(4) |
Seawater Intake for cooling at Hong Kong International Airport (East) |
811418 (from July 2017 onwards) |
820246 |
|
Notes:
(1) The seawater intakes of SR1 for the future
HKBCF is not yet in operation, hence no water quality impact monitoring was
conducted at this station. The future permanent location for SR1 during impact
monitoring is subject to finalisation after the HKBCF seawater is commissioned.
(2) Details
of selection criteria for the two heavy metals for early regular DCM monitoring
refer to the Detailed Plan on Deep Cement Mixing available on the dedicated 3RS
website (http://env.threerunwaysystem.com/en/ep-submissions.html). DCM
specific water quality monitoring parameters (total alkalinity and heavy
metals) were only conducted at C1 to C3, SR2, and IM1 to IM12.
(3) According
to the Baseline Water Quality Monitoring Report, C3 station is not adequately
representative as a control station of impact/
SR stations during the flood tide. The control reference has been changed from
C3 to SR2 from 1 September 2016 onwards.
(4) The
monitoring location for SR8 is subject to further changes due to silt curtain
arrangements and the progressive relocation of this seawater intake.
4.2 Monitoring Requirements and Schedule
In accordance with the Manual,
baseline water quality levels at the abovementioned representative water
quality monitoring stations were established as presented in the Baseline Water
Quality Monitoring Report.
General water quality monitoring and
early regular DCM water quality monitoring were conducted three days per week,
at mid-flood and mid-ebb tides, at the 22 water quality monitoring stations
during the reporting period. The sea conditions varied from calm to rough, and
the weather conditions varied from sunny to rainy during the monitoring period.
The water quality monitoring schedule
for the reporting period is updated and provided in Appendix C. The flood tide monitoring session on 22
August 2017 was cancelled due to hoisting Strong Wind Signal No. 3 and adverse
sea condition.
4.2.1 Action and
Limit Levels for Water Quality Monitoring
The Action and Limit Levels for general water
quality monitoring and regular DCM monitoring stipulated in the EM&A
programme for triggering the relevant investigation and follow-up procedures
under the programme are presented in Table 4.2. The control and impact stations during flood
tide and ebb tide for general water quality monitoring and regular DCM monitoring
are presented in Table 4.3.
Table 4.2: Action and Limit Levels for General Water Quality Monitoring
and Regular DCM Monitoring
|
Parameters |
Action Level (AL) |
Limit Level (LL) |
||
|
Action and Limit Levels for general water quality monitoring and regular DCM monitoring (excluding SR1& SR8) |
||||
|
DO in mg/L (Surface, Middle & Bottom) |
Surface and Middle 4.5 mg/L |
Surface and Middle 4.1 mg/L 5 mg/L for Fish Culture Zone (SR7) only |
||
|
Bottom 3.4 mg/L |
Bottom 2.7 mg/L |
|||
|
Suspended Solids (SS) in mg/L |
23 |
or 120% of upstream control station at the same tide of the same day, whichever is higher |
37 |
or 130% of upstream control station at the same tide of the same day, whichever is higher |
|
Turbidity in NTU |
22.6 |
36.1 |
||
|
Total Alkalinity in ppm |
95 |
99 |
||
|
Representative Heavy Metals for early regular DCM monitoring (Chromium) |
0.2 |
0.2 |
||
|
Representative Heavy Metals for early regular DCM monitoring (Nickel) |
3.2 |
|
3.6 |
|
|
Action and Limit Levels SR1 |
|
|
|
|
|
SS (mg/l) |
To be determined prior to its commissioning |
To be determined prior to its commissioning |
||
|
Action and Limit Levels SR8 |
|
|
|
|
|
SS (mg/l) |
52 |
|
60 |
|
Notes:
(1) For DO measurement, non-compliance
occurs when monitoring result is lower than the limits.
(2) For parameters other than DO,
non-compliance of water quality results when monitoring results is higher than
the limits.
(3) Depth-averaged results are used
unless specified otherwise.
(4)
Details of selection criteria for the two heavy metals
for early regular DCM monitoring refer to the Detailed Plan on Deep Cement
Mixing available on the dedicated 3RS website (http://env.threerunwaysystem.com/en/ep-submissions.html)
(5) The Action and Limit Levels for the
two representative heavy metals chosen will be the same as that for the
intensive DCM monitoring.
Table 4.3: The
Control and Impact Stations during Flood Tide and Ebb Tide for General Water
Quality Monitoring and Regular DCM Monitoring
|
Control Station |
Impact Stations |
|
Flood Tide |
|
|
C1 |
IM1, IM2, IM3, IM4, IM5, IM6, IM7, IM8, SR3 |
|
SR2^1 |
IM7, IM8, IM9, IM10, IM11, IM12, SR1A, SR3, SR4A, SR5A, SR6, SR8 |
|
Ebb Tide |
|
|
C1 |
SR4A, SR5A, SR6 |
|
C2 |
IM1, IM2, IM3, IM4, IM5, IM6, IM7, IM8, IM9, IM10, IM11, IM12, SR1A, SR2, SR3, SR7, SR8 |
^1 As
per findings of Baseline Water Quality Monitoring Report, the control reference
has been changed from C3 to SR2 from 1 Sep 2016 onwards.
4.3
Monitoring
Equipment
Table 4.4 summarises the equipment used for monitoring of
specific water quality parameters under the impact water quality monitoring
programme.
Table 4.4: Water Quality Monitoring
Equipment
|
Equipment |
Brand and Model |
Last Calibration Date |
|
Multifunctional Meter (measurement of DO, pH, temperature, salinity and turbidity) |
YSI ProDSS (serial no. 15M101244) |
16 Jun 2017 |
|
YSI ProDSS (serial no. 16J101716) |
16 Jun 2017 |
|
|
YSI 6920 V2 (serial no. 00019CB2) |
16 Jun 2017 |
|
|
YSI 6920 V2 (serial no. 000109DF) |
16 Jun 2017 |
|
|
Digital Titrator (measurement of total alkalinity) |
Titrette Digital Burette 50ml Class A (serial no.10N65665) |
19 Jun 2017 |
Other
equipment used as part of the impact water quality monitoring programme are listed
in Table 4.5.
Table 4.5: Other Monitoring Equipment
|
Equipment |
Brand and Model |
|
Water Sampler |
Van Dorn Water Sampler |
|
Positioning Device (measurement of GPS) |
Garmin eTrex Vista HCx |
|
Current Meter (measurement of current speed and direction, and water depth) |
Sontek HydroSurveyor |
4.4 Monitoring Methodology
4.4.1 Measuring Procedure
Water
quality monitoring samples were taken at three depths (at 1m below surface, at
mid-depth, and at 1m above bottom) for locations with water depth >6m. For
locations with water depth between 3m and 6m, water samples were taken at two
depths (surface and bottom). For locations with water depth <3m, only the mid-depth was taken. Duplicate water
samples were taken and analysed.
The water samples for all monitoring
parameters were collected, stored, preserved and analysed according to
the Standard Methods, APHA 22nd ed. and/or other methods as agreed
by the EPD. In-situ measurements at monitoring locations including temperature,
pH, DO, turbidity, salinity and water depth were collected by equipment listed
in Table 4.4 and
Table 4.5.
Water samples for heavy metals and SS analysis were stored in high density
polythene bottles with no preservative added, packed in ice (cooled to 4 ºC
without being frozen), delivered to the laboratory within 24 hours of
collection.
4.4.2 Maintenance and Calibration
Calibration
of In-situ Instruments
Wet bulb calibration for a DO meter
was carried out before commencement of monitoring and after completion of all
measurements each day. Calibration was not conducted at each monitoring
location as daily calibration is adequate for the type of DO meter employed. A
zero check in distilled water was performed with the turbidity probe at least
once per monitoring day. The probe was then calibrated with a solution of known
NTU. In addition, the turbidity probe was calibrated at least twice per month
to establish the relationship between turbidity readings (in NTU) and levels of
suspended solids (in mg/L). Accuracy check of the digital titrator was
performed at least once per monitoring day.
Calibration certificates of the
monitoring equipment used in the monitoring period provided in Appendix D of the
Construction Phase Monthly EM&A Report No.18 are still valid. Any updates
of calibration certificates will be reported in the Monthly EM&A report if
necessary.
4.4.3 Laboratory Measurement / Analysis
Analysis of
SS and heavy metals have been carried out by a HOKLAS accredited laboratory,
ALS Technichem
(HK) Pty Ltd (Reg. No. HOKLAS 066). Sufficient water samples were collected at
all the monitoring stations for carrying out the laboratory SS and heavy metals
determination. The SS and heavy metals determination works were started within
24 hours after collection of the water samples. The analysis of SS and heavy
metals have followed the standard methods summarised in Table 4.6. The QA/QC procedures for
laboratory measurement/ analysis of SS and heavy metals were presented in
Appendix F of the Construction Phase Monthly EM&A Report No.8.
Table 4.6: Laboratory Measurement/ Analysis of SS and
Heavy Metals
|
Parameters |
Instrumentation |
Analytical Method |
Reporting Limit |
|
Suspended Solid (SS) |
Analytical Balance |
APHA 2540D |
2 mg/L |
|
Heavy Metals |
|
|
|
|
Chromium (Cr) |
ICP-MS |
USEPA 6020A |
0.2 µg/L |
|
Nickel (Ni) |
ICP-MS |
USEPA 6020A |
0.2 µg/L |
4.5
Analysis
and Interpretation of Monitoring Results
4.5.1 Summary of Monitoring Results
The water quality monitoring results for total
alkalinity and chromium obtained during the reporting period did not trigger
their corresponding Action and Limit Levels stipulated in the EM&A
programme for triggering the relevant investigation and follow-up procedures
under the programme if being exceeded. For DO, turbidity, SS, and nickel, some
of the testing results exceeded the relevant Action or Limit Levels, and the
corresponding investigations were conducted accordingly. It should be noted
that two typhoons, namely Typhoon Hato and Typhoon Pakhar hit Hong Kong during August 2017. The water quality
monitoring results might be affected by these typhoons. Detailed analysis of the exceedances are presented in Section 4.5.2.
4.5.2 Summary of Findings for Investigation of Exceedances
During the reporting
period, water quality monitoring was conducted at 12 IM stations, 7 SR
stations, and 3 control stations in accordance with the Manual. The purpose of
water quality monitoring at the IM stations is to promptly capture any
potential water quality impact from the Project before it could become apparent
at sensitive receivers (represented by the SR stations).
During the monitoring
period, testing results exceeding the corresponding Action or Limit Levels were
recorded on five monitoring days. Details of the exceedance cases are presented
below.
Findings for DO Exceedances (Mid-Ebb
Tide)
Table
4.7
and Table 4.8
presents a summary
of the DO compliance status at IM and SR stations during
mid-ebb tide for the reporting period.
Table 4.7: Summary of DO (Surface and Middle) Compliance Status (Mid-Ebb
Tide)
|
IM1 |
IM2 |
IM3 |
IM4 |
IM5 |
IM6 |
IM7 |
IM8 |
IM9 |
IM10 |
IM11 |
IM12 |
SR2 |
SR3 |
SR4A |
SR5A |
SR6 |
SR7 |
|
|
01/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
03/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
05/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
08/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
10/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
12/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
15/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
17/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
19/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
22/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
24/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
26/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
29/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
31/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
No. of Exceedance |
2 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
1 |
2 |
0 |
0 |
1 |
|
Note: Detailed results are presented in Appendix D. |
||||||||||||||||||
|
|
No exceedance of Action and Limit Level |
|||||||||||||||||
|
|
Exceedance of Action Level recorded at monitoring station located downstream of the Project based on dominant tidal flow |
|||||||||||||||||
|
|
Exceedance of Action Level recorded at monitoring station located upstream of the Project based on dominant tidal flow |
|||||||||||||||||
|
|
Exceedance of Limit Level recorded at monitoring station located downstream of the Project based on dominant tidal flow |
|||||||||||||||||
|
|
Exceedance of Limit Level recorded at monitoring station located upstream of the Project based on dominant tidal flow |
|||||||||||||||||
|
|
Upstream station with respect to the Project during the respective tide based on dominant tidal flow |
|||||||||||||||||
Table 4.8: Summary of DO (Bottom) Compliance Status (Mid-Ebb Tide)
|
IM1 |
IM2 |
IM3 |
IM4 |
IM5 |
IM6 |
IM7 |
IM8 |
IM9 |
IM10 |
IM11 |
IM12 |
SR2 |
SR3 |
SR4A |
SR5A |
SR6 |
SR7 |
|
|
01/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
03/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
05/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
08/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
10/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
12/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
15/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
17/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
19/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
22/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
24/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
26/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
29/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
31/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
No. of Exceedance |
1 |
0 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
1 |
1 |
0 |
0 |
0 |
|
Note: Detailed results are presented in Appendix D. |
||||||||||||||||||
|
Legend: |
||||||||||||||||||
|
|
No exceedance of Action and Limit Level |
|||||||||||||||||
|
|
Exceedance of Action Level recorded at monitoring station located downstream of the Project based on dominant tidal flow |
|||||||||||||||||
|
|
Exceedance of Action Level recorded at monitoring station located upstream of the Project based on dominant tidal flow |
|||||||||||||||||
|
|
Upstream station with respect to the Project during the respective tide based on dominant tidal flow |
|||||||||||||||||
Exceedances of Action or Limit
Levels were recorded on 5 and 22 August 2017. Repeat in-situ measurement was
conducted on 6 August 2017 as stipulated in the Manual and no exceedance was
recorded during the repeat measurement. However, as Hurricane Signal No. 10 was
hoisted on 23 August 2017, the repeat in-situ measurement on 23 August 2017 was
cancelled. Regular monitoring at all stations resumed on 24 August 2017. No
exceedance was recorded during the repeat measurement. As some of the
exceedances occurred at stations located downstream of the Project, which might
be affected by Project’s construction activities, exceedance investigation was
carried out.
As part of the investigation on
downstream exceedance events, details of the Project’s marine construction
activities on the concerned monitoring day was collected, as well as any
observations during the monitoring. The findings are summarized in Table 4.9.
Table 4.9:
Summary of Findings from Investigations of DO Exceedances
|
Date |
Marine construction works nearby |
Approximate distance from marine construction works*
|
Status of water quality measures (if applicable) |
Construction vessels in the vicinity |
Turbidity / Silt plume observed near the monitoring station |
Exceedance due to Project |
|
05/08/2017 |
DCM works Sand blanket laying |
Around 500m |
Silt curtain deployed |
No |
No |
No |
|
22/08/2017 |
DCM works Sand blanket laying |
Around 800m |
Silt curtain deployed |
No |
No |
No |
|
* This refers to the approximate distance between the marine construction works and the nearest monitoring stations with exceedance. |
||||||
According to the investigation
findings, it was confirmed that both DCM and sand blanket laying activities were
operating normally with silt curtains deployed as additional measures. The silt
curtains were maintained properly.
For the exceedance events at
downstream monitoring stations, namely IM1, SR4A and SR7 on 5 August 2017, it
is noted that DO concentration at surface and middle level at the corresponding
control station C2 was also lower than the Limit Level during the same tide.
Exceedances also occurred at upstream stations on the same day. Besides, lower
DO concentrations were recorded during baseline monitoring at these monitoring
stations. Based on these findings, the exceedances were possibly due to natural
fluctuation in the vicinity of these monitoring stations, and considered not
due to the Project.
Stand By Signal No. 1 was hoisted when exceedances were recorded
at IM1 and SR4A on 22 August 2017. Lower DO concentrations were recorded during
baseline monitoring at these monitoring stations. Besides, no exceedance was
recorded at other downstream monitoring stations, including IM2, which was
located closer to active construction works than IM1 and SR4A. Based on these
findings, the exceedances were possibly due to natural fluctuation in the
vicinity of these monitoring stations, and considered not due to the Project.
Findings
for Turbidity Exceedances (Mid-Ebb Tide)
Table 4.10 presents a
summary of the turbidity compliance status at IM and SR stations during mid-ebb
tide for the reporting period.
Table 4.10: Summary of Turbidity
Compliance Status (Mid-Ebb Tide)
|
IM1 |
IM2 |
IM3 |
IM4 |
IM5 |
IM6 |
IM7 |
IM8 |
IM9 |
IM10 |
IM11 |
IM12 |
SR2 |
SR3 |
SR4A |
SR5A |
SR6 |
SR7 |
|
|
01/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
03/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
05/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
08/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
10/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
12/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
15/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
17/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
19/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
22/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
24/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
26/08/2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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29/08/2017 |
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31/08/2017 |
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No. of Exceedance |
0 |
0 |
0 |
1 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
|
Note: Detailed results are presented in Appendix D. |
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Legend: |
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No exceedance of Action and Limit Level |
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Exceedance of Action Level recorded at monitoring station located downstream of the Project based on dominant tidal flow |
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Exceedance of Action Level recorded at monitoring station located upstream of the Project based on dominant tidal flow |
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Upstream station with respect to the Project during the respective tide based on dominant tidal flow |
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Exceedances of Action Level were
recorded on one monitoring day. Stand By Signal No. 1 was
hoisted when the exceedances were recorded. Due to hoisting Gale or Storm
Signal No.8 SE, the repeat measurement on 27 August 2017 was rescheduled to 28
August 2017. No exceedance was recorded during the repeat measurement. As one
of the exceedances occurred at a station located upstream of the Project, which
would unlikely be affected by Project’s construction activities, exceedance
investigation focusing on downstream exceedance events was carried out.
As part of the investigation on downstream exceedance events, details
of the Project’s marine construction activities on concerned monitoring day
were collected, as well as any observations during the monitoring. The findings
are summarized in Table 4.11.
Table 4.11: Summary of Findings from
Investigations of Turbidity Exceedances
|
Date |
Marine construction works nearby |
Approximate distance from marine construction works*
|
Status of water quality measures (if applicable) |
Construction vessels in the vicinity |
Turbidity / Silt plume observed near the monitoring station |
Exceedance due to Project |
|
26/08/2017 |
DCM works Sand blanket laying |
Around 500m |
Silt curtain deployed |
No |
No |
No |
|
* This refers to the approximate distance between the marine construction works and the nearest monitoring stations with exceedance. |
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According to the investigation
findings, it was confirmed that both DCM and sand blanket laying activities
were operating normally with silt curtains deployed as additional measures. The
silt curtains were maintained properly.
For the exceedance events at
downstream monitoring stations, namely IM4 and SR4A, it is noted from Table 4.10
that the exceedances appeared to be isolated cases with no temporal trend and
no clear spatial trend to indicate turbidity rising due to Project activities.
The investigation results shown in Table 4.11 also
showed that no construction vessel, nor silt plume was
observed in the vicinity of IM4 and SR4A on 26 August 2017. It is also noted
that no exceedance was recorded at monitoring station IM3, which is located
similarly downstream and close to active construction works on 26 August 2017
during ebb tide, while no exceedances were identified in the repeat turbidity
measurements. Based on the above, the exceedances were considered not due to
the Project, and were possibly due to natural fluctuation in vicinity of IM4
and SR4A.
Findings
for Turbidity Exceedances (Mid-Flood Tide)
Table
4.12 presents a summary of the turbidity compliance status at IM stations
during mid-flood tide for the reporting period.
Table 4.12: Summary of Turbidity Compliance Status
(Mid-Flood Tide)
|
IM1 |
IM2 |
IM3 |
IM4 |
IM5 |
IM6 |
IM7 |
IM8 |
IM9 |
IM10 |
IM11 |
IM12 |
SR3 |
SR4A |
SR5A |
SR6 |
SR7 |
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01/08/2017 |
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03/08/2017 |
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05/08/2017 |
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08/08/2017 |
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10/08/2017 |
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