Executive Summary
The Hong Kong-Zhuhai-Macao
Bridge (HZMB) Hong Kong Link Road (HKLR) serves to connect the HZMB Main Bridge
at the Hong Kong Special Administrative Region (HKSAR) Boundary and the HZMB
Hong Kong Boundary Crossing Facilities (HKBCF) located at the north eastern
waters of the Hong Kong International Airport (HKIA).
The HKLR project has been
separated into two contracts. They are Contract No. HY/2011/03 Hong
Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and
Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract)
and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link
Road-Section between HKSAR Boundary and Scenic Hill.
China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department as the
Contractor to undertake the construction works of Contract No. HY/2011/03. The main works of the Contract include
land tunnel at Scenic Hill, tunnel underneath Airport Road and Airport Express
Line, reclamation and tunnel to the east coast of the Airport Island, at-grade
road connecting to the HKBCF and highway works of the HKBCF within the Airport
Island and in the vicinity of the HKLR reclamation. The Contract is part of the HKLR Project
and HKBCF Project, these projects are considered to be ¡§Designated Projects¡¨,
under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap
499) and Environmental Impact Assessment (EIA) Reports (Register No.
AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project. The current Environmental Permit (EP)
EP-352/2009/D for HKLR and EP-353/2009/I for HKBCF were issued on 22 December
2014 and 17 July 2015, respectively. These documents are available through the
EIA Ordinance Register. The construction phase of Contract was
commenced on 17 October 2012.
BMT Asia Pacific Limited
has been appointed by the Contractor to implement the Environmental Monitoring
& Audit (EM&A) programme for the Contract in accordance with the
Updated EM&A Manual for HKLR (Version 1.0) and will be providing
environmental team services to the Contract.
This is the thirty-sixth Monthly
EM&A report for the Contract which summaries the monitoring results and
audit findings of the EM&A programme during the reporting period from 1 to
30 September 2015.
Environmental
Monitoring and Audit Progress
The monthly EM&A
programme was undertaken in accordance with the Updated EM&A Manual for
HKLR (Version 1.0). A summary of the
monitoring activities during this reporting month is listed below:
1-hr TSP
Monitoring
|
2, 8, 14, 18, 24 and 30 September 2015
|
24-hr TSP
Monitoring
|
1, 7, 11, 17, 23 and 29 September 2015
|
Noise
Monitoring
|
4, 8, 14, 24 and 30 September
2015
|
Water Quality
Monitoring
|
2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28 and 30 September 2015
|
Chinese White
Dolphin Monitoring
|
2, 11, 17 and 29 September 2015
|
Mudflat
Monitoring (Sedimentation Rate)
|
10 September 2015
|
Mudflat
Monitoring (Ecology)
|
5, 6, 10, 12 and 13 September 2015
|
Site
Inspection
|
2, 9, 16, 25
and 30 September 2015
|
Due
to bad weather condition on 2 Sep 2015, noise monitoring at NMS5 was
rescheduled from 2 Sep 2015 to 4 Sep 2015.
Due
to boat availability issue, the dolphin monitoring schedule was rescheduled
from 15 Sep 2015 to 17 Sep 2015 and from 21 Sep 2015 to 29 Sep 2015.
Breaches of Action and Limit Levels
A summary of environmental
exceedances for this reporting month is as follows:
Environmental Monitoring
|
Parameters
|
Action Level (AL)
|
Limit Level (LL)
|
Air Quality
|
1-hr TSP
|
0
|
0
|
24-hr TSP
|
0
|
0
|
Noise
|
Leq (30 min)
|
0
|
0
|
Water Quality
|
Suspended solids level (SS)
|
1
|
0
|
Turbidity level
|
0
|
0
|
Dissolved oxygen level (DO)
|
0
|
0
|
One Action Level exceedances of suspended solid level were recorded
during the reporting month.
Complaint Log
There were no complaints received
in relation to the environmental impacts during the reporting period. However, EPD informed SOR and IEC that
there was an enquiry regarding untreated wastewater discharge on 29 September
2015 via email. An investigation is
being undertaken and investigation report will be sent to EPD for record.
Notifications
of Summons and Prosecutions
There were no notifications
of summons or prosecutions received during this reporting month.
Reporting
Changes
This report has been
developed in compliance with the reporting requirements for the subsequent
EM&A reports as required by the Updated EM&A Manual for HKLR (Version
1.0).
The proposal for the change
of Action Level and Limit Level for suspended solid and turbidity was approved
by EPD on 25 March 2013.
The revised Event and
Action Plan for dolphin monitoring was approved by EPD on 6 May 2013.
The original monitoring
station at IS(Mf)9 (Coordinate- East:813273, North 818850) was observed inside
the perimeter silt curtain of Contract HY/2010/02 on 1 July 2013, as such the
original impact water quality monitoring location at IS(Mf)9 was temporarily
shifted outside the silt curtain. As advised by the Contractor of HY/2010/02 in
August 2013, the perimeter silt curtain was shifted to facilitate safe anchorage
zone of construction barges/vessels until end of 2013 subject to construction
progress. Therefore, water quality
monitoring station IS(Mf)9 was shifted to 813226E and
818708N since 1 July 2013.
According to the water quality monitoring team¡¦s observation on 24 March
2014, the original monitoring location of IS(Mf)9 was
no longer enclosed by the perimeter silt curtain of Contract HY/2010/02. Thus,
the impact water quality monitoring works at the original monitoring location
of IS(Mf)9 has been resumed since 24 March 2014.
Transect lines 1, 2, 7, 8,
9 and 11 for dolphin monitoring have been revised due to the obstruction of the
permanent structures associated with the construction works of HKLR and the
southern viaduct of TM-CLKL, as well as provision of adequate buffer distance
from the Airport Restricted Areas.
The EPD issued a memo and confirmed that they had no objection on the
revised transect lines on 19 August 2015.
Future
Key Issues
The future key issues
include potential noise, air quality, water quality and ecological impacts and
waste management arising from the following construction activities to be
undertaken in the upcoming month:
- Dismantling/trimming of Temporary 40mm Stone Platform for
Construction of Seawall at Portion X;
- Filling Works behind Stone Platform at Portion X;
- Construction of Seawall at Portion X;
- Loading and Unloading Filling Material at Portion X;
- Pipe Piling at Portion X;
- Band Drains Installation at Portion X;
- Excavation and Lateral Support Works at Scenic Hill Tunnel (Cut
& Cover Tunnel) at Portion X;
- Laying Blinding Layer for Tunnel Box Structure at Scenic Hill
Tunnel (Cut & Cover Tunnel) at Portion X;
- Construction of Tunnel Box Structure at Scenic Hill Tunnel (Cut
& Cover Tunnel) at Portion X
- Socket H-Piling work at Scenic Hill Tunnel (Cut & Cover Tunnel)
at Portion X;
- Construction of Sheet Pile at Scenic Hill Tunnel (Cut & Cover
Tunnel) at Portion X;
- Excavation Works for HKBCF to Airport Tunnel at Portion X;
- Sheet Piling Works for HKBCF to Airport Tunnel East (Cut &
Cover Tunnel) at Portion X;
- Socket H-Piling Works for HKBCF to Airport Tunnel East (Cut
&Cover Tunnel) at Portion X;
- Pipe Piling Works for HKBCF to Airport Tunnel East (Cut &Cover
Tunnel) at Portion X;
- Works for Diversion of Airport Road;
- Utilities Detection at Airport Road / Airport Express Line/ East
Coast Road;
- Establishment of Site Access at Airport Road / Airport Express
Line/East Coast Road;
- Canopy Pipe Drilling / Mined Tunnel Excavation / Box Jacking
underneath Airport Road and Airport Express Line;
- Excavation and Lateral Support Works at shaft 3 extension north
shaft & south shaft at Kwo Lo Wan Road;
- Excavation and Lateral Support Works for HKBCF to Airport Tunnel
West (Cut & Cover Tunnel) at Airport Road;
- Utility Culvert Excavation at Portion Y;
- Highway Operation and Maintenance Area Building Foundation &
Sub-structure Works at Portion Y;
- Excavation for Scenic Hill Tunnel at West Portal; and
- Ventilation Building Foundation and
Superstructure Works at West Portal.
1.1.2
The HKLR project has been
separated into two contracts. They
are Contract
No. HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section
between Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter
referred to as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao
Bridge Hong Kong Link Road-Section between HKSAR Boundary and Scenic Hill.
1.1.3
China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department (HyD) as
the Contractor to undertake the construction works of Contract No.
HY/2011/03. The Contract is part of the HKLR Project and HKBCF Project, these
projects are considered to be ¡§Designated Projects¡¨, under Schedule 2 of the
Environmental Impact Assessment (EIA) Ordinance (Cap 499) and Environmental
Impact Assessment (EIA) Reports (Register No. AEIAR-144/2009 and
AEIAR-145/2009) were prepared for the Project. The current Environmental Permit (EP)
EP-352/2009/D for HKLR and EP-353/2009/I for HKBCF were issued on 22 December
2014 and 17 July 2015, respectively. These documents are available through the
EIA Ordinance Register. The construction phase of
Contract was commenced on 17 October 2012.
Figure 1.1 shows the project
site boundary. The works areas are shown in Appendix O.
1.1.4
The Contract includes
the following key aspects:
¡P
New reclamation
along the east coast of the approximately 23 hectares.
¡P
Tunnel of Scenic
Hill (Tunnel SHT) from Scenic Hill to the new reclamation, of approximately 1km
in length with three (3) lanes for the east bound carriageway heading to the
HKBCF and four (4) lanes for the westbound carriageway heading to the HZMB Main
Bridge.
¡P
An abutment of the
viaduct portion of the HKLR at the west portal of Tunnel SHT and associated
road works at the west portal of Tunnel SHT.
¡P
An at grade road on
the new reclamation along the east coast of the HKIA to connect with the HKBCF,
of approximately 1.6 km along dual 3-lane carriageway with hard shoulder for
each bound.
¡P
Road links between
the HKBCF and the HKIA including new roads and the modification of existing
roads at the HKIA, involving viaducts, at grade roads and a Tunnel HAT.
¡P
A highway operation
and maintenance area (HMA) located on the new reclamation, south of the Dragonair Headquarters Building, including the construction
of buildings, connection roads and other associated facilities.
¡P
Associated civil,
structural, building, geotechnical, marine, environmental protection,
landscaping, drainage and sewerage, tunnel and highway electrical and
mechanical works, together with the installation of street lightings, traffic
aids and sign gantries, water mains and fire hydrants, provision of facilities
for installation of traffic control and surveillance system (TCSS), reprovisioning works of affected existing facilities,
implementation of transplanting, compensatory planting and protection of
existing trees, and implementation of an environmental monitoring and audit
(EM&A) program.
1.1.5
This is the thirty-sixth Monthly EM&A report for the Contract which summarizes the monitoring
results and audit findings of the EM&A programme
during the reporting period from 1 to 30 September 2015.
1.1.6 BMT Asia Pacific Limited has been
appointed by the Contractor to implement the EM&A programme
for the Contract in accordance with the Updated EM&A Manual for HKLR
(Version 1.0) for HKLR and will be providing environmental team services to the
Contract. Ramboll Environ Hong Kong Ltd. was employed by HyD as the Independent
Environmental Checker (IEC) and Environmental Project Office (ENPO) for the
Project. The project organization with regard to the
environmental works is as follows.
1.2.1 The project organization structure and lines of
communication with respect to the on-site environmental management structure is
shown in Appendix A. The key personnel contact names and
numbers are summarized in Table 1.1.
Table
1.1 Contact
Information of Key Personnel
Party
|
Position
|
Name
|
Telephone
|
Fax
|
Supervising Officer¡¦s Representative
(Ove Arup & Partners Hong
Kong Limited)
|
(Chief
Resident Engineer, CRE)
|
Robert Antony
Evans
|
3968 0801
|
2109 1882
|
Environmental Project Office /
Independent Environmental Checker
(Ramboll Environ Hong Kong Limited)
|
Environmental Project Office Leader
|
Y. H. Hui
|
3465
2888
|
3465
2899
|
Independent Environmental Checker
|
Antony Wong
|
3465
2888
|
3465
2899
|
Contractor
(China State Construction Engineering (Hong Kong) Ltd)
|
Project Manager
|
S. Y. Tse
|
3968
7002
|
2109
2588
|
Environmental Officer
|
Federick Wong
|
3968
7117
|
2109
2588
|
Environmental Team
(BMT Asia Pacific)
|
Environmental Team Leader
|
Claudine Lee
|
2241
9847
|
2815
3377
|
24
hours complaint hotline
|
---
|
---
|
5699
5730
|
---
|
1.3
Construction Programme
1.3.1 A copy
of the Contractor¡¦s construction programme is
provided in Appendix B.
1.4
Construction Works
Undertaken During the Reporting Month
1.4.1 A summary
of the construction activities undertaken during this reporting month is shown
in Table 1.2.
Table 1.2 Construction
Activities During Reporting Month
Description
of Activities
|
Site
Area
|
Dismantling/trimming of temporary 40mm
stone platform for construction of seawall
|
Portion X
|
Filling works behind stone platform
|
Portion X
|
Construction of seawall
|
Portion X
|
Loading and unloading of filling
materials
|
Portion X
|
Band drains installation
|
Portion X
|
Excavation and lateral support works for Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Socket H-Piling work for Scenic Hill
Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Laying blinding layer for tunnel box
structure at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of
Sheet Pile
at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of tunnel box structure at
Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Pipe piling works for HKBCF to Airport
Tunnel East (Cut & Cover Tunnel)
|
Portion X
|
Excavation for HKBCF to Airport Tunnel
|
Portion X
|
Excavation for Scenic Hill Tunnel
|
West Portal
|
Ventilation
building foundation and superstructure works
|
West Portal
|
Works for diversion of Airport Road
|
Airport Road
|
Utilities detection
|
Airport Road/ Airport Express Line/ East
Coast Road
|
Establishment of Site Access
|
Airport Road/ Airport Express Line/ East
Coast Road
|
Canopy pipe drilling underneath Airport
Express Line
|
Airport Express Line
|
Excavation and lateral support works at
shaft 3 extension north shaft & south shaft
|
Kwo
Lo Wan Road
|
Excavation and
Lateral Support Works for HKBCF to Airport Tunnel West (Cut & Cover
Tunnel)
|
Airport Road
|
Utility culvert excavation
|
Portion Y
|
Highway
Operation and Maintenance Area Building foundation & sub-structure works
|
Portion Y
|
2.1
Monitoring Requirements
2.1.1 In
accordance with the Contract Specific EM&A Manual, baseline 1-hour and
24-hour TSP levels at two air quality monitoring stations were
established. Impact 1-hour TSP
monitoring was conducted for at least three times every 6 days, while impact
24-hour TSP monitoring was carried out for at least once every 6 days. The
Action and Limit Level for 1-hr TSP and 24-hr TSP are provided in Table 2.1 and Table 2.2, respectively.
Table 2.1 Action
and Limit Levels for 1-hour TSP
Monitoring
Station
|
Action Level,
µg/m3
|
Limit Level,
µg/m3
|
AMS 5 ¡V Ma Wan Chung Village (Tung Chung)
|
352
|
500
|
AMS 6 ¡V Dragonair /
CNAC (Group) Building (HKIA)
|
360
|
Table 2.2 Action
and Limit Levels for 24-hour TSP
Monitoring
Station
|
Action Level,
µg/m3
|
Limit Level,
µg/m3
|
AMS 5 ¡V Ma Wan Chung Village (Tung Chung)
|
164
|
260
|
AMS 6 ¡V Dragonair /
CNAC (Group) Building (HKIA)
|
173
|
260
|
2.2.1 24-hour
TSP air quality monitoring was performed using High Volume Sampler (HVS)
located at each designated monitoring station. The HVS meets all the
requirements of the Contract Specific EM&A Manual. Portable direct reading dust meters were
used to carry out the 1-hour TSP monitoring. Brand and model of the equipment is
given in Table 2.3.
Table 2.3 Air
Quality Monitoring Equipment
Equipment
|
Brand and
Model
|
Portable direct reading
dust meter (1-hour TSP)
|
Sibata Digital Dust Monitor
(Model No. LD-3B)
|
High Volume Sampler
(24-hour TSP)
|
Tisch Environmental Mass
Flow Controlled Total Suspended Particulate (TSP) High Volume Air Sampler
(Model No. TE-5170)
|
2.3.1 Monitoring
locations AMS5 and AMS6 were set
up at the proposed locations in accordance with Contract Specific EM&A
Manual.
2.3.2 Figure 2.1 shows the locations of monitoring stations. Table 2.4 describes the details of the
monitoring stations.
Table
2.4 Locations
of Impact Air Quality Monitoring Stations
Monitoring Station
|
Location
|
AMS5
|
Ma Wan Chung Village
(Tung Chung)
|
AMS6
|
Dragonair / CNAC (Group)
Building (HKIA)
|
2.4.1 Table 2.5 summarizes the monitoring parameters, frequency
and duration of impact TSP monitoring.
Table 2.5 Air
Quality Monitoring Parameters, Frequency and Duration
Parameter
|
Frequency and Duration
|
1-hour TSP
|
Three times every 6
days while the highest dust impact was expected
|
24-hour TSP
|
Once every 6 days
|
2.5.1 24-hour
TSP Monitoring
(a) The HVS was installed in the vicinity of the air
sensitive receivers. The following criteria were considered in the installation
of the HVS.
(i) A horizontal platform with appropriate support to
secure the sampler against gusty wind was provided.
(ii) The distance between the HVS and any obstacles,
such as buildings, was at least twice the height that the obstacle protrudes
above the HVS.
(iii) A minimum of 2 meters separation from walls,
parapets and penthouse for rooftop sampler was provided.
(iv) No furnace or incinerator flues are nearby.
(v) Airflow around the sampler was unrestricted.
(vi) Permission was obtained to set up the samplers and access to
the monitoring stations.
(vii) A secured supply of electricity was obtained to
operate the samplers.
(viii) The sampler was located more than 20 meters from any
dripline.
(ix) Any wire fence and gate, required to protect the
sampler, did not obstruct the monitoring process.
(x) Flow control accuracy was kept within ¡Ó2.5%
deviation over 24-hour sampling period.
(b) Preparation of Filter Papers
(i) Glass fibre filters, G810 were labelled and
sufficient filters that were clean and without pinholes were selected.
(ii) All filters were equilibrated in the conditioning
environment for 24 hours before weighing. The conditioning environment
temperature was around 25 ¢XC
and not variable by more than ¡Ó3 ¢XC;
the relative humidity (RH) was < 50% and not variable by more than ¡Ó5%. A convenient working RH was 40%.
(iii) All filter papers were prepared and analysed by ALS
Technichem (HK) Pty Ltd., which is a HOKLAS
accredited laboratory and has comprehensive quality assurance and quality
control programmes.
(c) Field Monitoring
(i) The power supply was checked to ensure the HVS
works properly.
(ii) The filter holder and the area surrounding the
filter were cleaned.
(iii) The filter holder was removed by loosening the four
bolts and a new filter, with stamped number upward, on a supporting screen was
aligned carefully.
(iv) The filter was properly aligned on the screen so that
the gasket formed an airtight seal on the outer edges of the filter.
(v) The swing bolts were fastened to hold the filter
holder down to the frame. The
pressure applied was sufficient to avoid air leakage at the edges.
(vi) Then the shelter lid was closed and was secured with
the aluminium strip.
(vii) The HVS was warmed-up for about 5 minutes to establish
run-temperature conditions.
(viii) A new flow rate record sheet was set into the flow
recorder.
(ix) On site temperature and atmospheric pressure
readings were taken and the flow rate of the HVS was checked and adjusted at
around 1.1 m3/min, and complied with the range specified in the
Updated EM&A Manual for HKLR (Version 1.0) (i.e. 0.6-1.7 m3/min).
(x) The programmable digital timer was set for a
sampling period of 24 hours, and the starting time, weather condition and the
filter number were recorded.
(xi) The initial elapsed time was recorded.
(xii) At the end of sampling, on site temperature and
atmospheric pressure readings were taken and the final flow rate of the HVS was
checked and recorded.
(xiii) The final elapsed time was recorded.
(xiv) The sampled filter was removed carefully and folded
in half length so that only surfaces with collected
particulate matter were in contact.
(xv) It was then placed in a clean plastic envelope and
sealed.
(xvi) All monitoring information was recorded on a
standard data sheet.
(xvii) Filters were then sent to ALS Technichem
(HK) Pty Ltd. for analysis.
(d) Maintenance and Calibration
(i) The HVS and its accessories were maintained in good
working condition, such as replacing motor brushes routinely and checking
electrical wiring to ensure a continuous power supply.
(ii) 5-point calibration of the HVS was conducted using
TE-5025A Calibration Kit
prior to the commencement of baseline monitoring. Bi-monthly 5-point
calibration of the HVS will be carried out during impact monitoring.
(iii) Calibration certificate of the HVSs are provided in
Appendix C.
2.5.2 1-hour
TSP Monitoring
(a) Measuring Procedures
The measuring procedures of
the 1-hour dust meter were in accordance with the Manufacturer¡¦s Instruction Manual
as follows:-
(i)
Turn
the power on.
(ii) Close the air collecting opening cover.
(iii) Push the ¡§TIME SETTING¡¨ switch to [BG].
(iv) Push ¡§START/STOP¡¨ switch to perform background
measurement for 6 seconds.
(v) Turn the knob at SENSI ADJ position to insert the
light scattering plate.
(vi) Leave the equipment for 1 minute upon ¡§SPAN CHECK¡¨ is
indicated in the display.
(vii) Push ¡§START/STOP¡¨ switch to perform automatic
sensitivity adjustment. This measurement takes 1 minute.
(viii) Pull out the knob and return it to MEASURE
position.
(ix) Push the ¡§TIME SETTING¡¨ switch the time set in the
display to 3 hours.
(x) Lower down the air collection opening cover.
(xi) Push ¡§START/STOP¡¨ switch to start measurement.
(b) Maintenance and Calibration
(i) The
1-hour TSP meter was calibrated at 1-year intervals against a Tisch Environmental Mass Flow Controlled Total Suspended
Particulate (TSP) High Volume Air Sampler. Calibration certificates of the
Laser Dust Monitors are provided in Appendix
C.
2.6.1 The
schedule for air quality monitoring October 2015 is provided in Appendix D.
2.7.1
The monitoring results for 1-hour TSP and
24-hour TSP are summarized in Tables 2.6
and 2.7 respectively. Detailed
impact air quality monitoring results and relevant graphical plots are
presented in Appendix E.
Table 2.6 Summary of 1-hour TSP
Monitoring Results During the Reporting Month
Monitoring Station
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
AMS5
|
95
|
58 - 151
|
352
|
500
|
AMS6
|
97
|
66 - 138
|
360
|
500
|
Table 2.7 Summary
of 24-hour TSP Monitoring Results During the
Reporting Month
Monitoring
Station
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
AMS5
|
36
|
18 - 77
|
164
|
260
|
AMS6
|
61
|
34 - 119
|
173
|
260
|
2.7.2
No Action and Limit
Level exceedances of 1-hour TSP and 24-hour TSP were recorded at AMS5 and AMS6
during the reporting month.
2.7.3 The event action plan is annexed in Appendix F.
2.7.4
The wind data obtained from
the on-site weather
station during the
reporting month is shown in Appendix G.
3.1.1 In
accordance with the Contract Specific EM&A Manual, impact noise monitoring
was conducted for at least once per week during the construction phase of the
Project. The Action and Limit level of the noise monitoring is provided in Table 3.1.
Table 3.1 Action
and Limit Levels for Noise during Construction Period
Monitoring Station
|
Time Period
|
Action Level
|
Limit Level
|
NMS5 ¡V Ma Wan
Chung Village (Ma Wan Chung Resident Association) (Tung Chung)
|
0700-1900
hours on normal weekdays
|
When one
documented complaint is received
|
75 dB(A)
|
3.2.1 Noise
monitoring was performed using sound level meters at each designated monitoring
station. The sound level meters
deployed comply with the International Electrotechnical
Commission Publications (IEC) 651:1979 (Type 1) and 804:1985 (Type 1)
specifications. Acoustic calibrator
was deployed to check the sound level meters at a known sound pressure
level. Brand and model of the
equipment are given in Table 3.2.
Table 3.2 Noise
Monitoring Equipment
Equipment
|
Brand and Model
|
Integrated
Sound Level Meter
|
B&K 2238
|
Acoustic
Calibrator
|
B&K 4231
|
3.3.1
Monitoring location NMS5 was set
up at the proposed locations in accordance with Contract Specific EM&A
Manual.
3.3.2
Figure 2.1 shows
the locations of monitoring stations. Table
3.3
describes the details of the monitoring stations.
Table 3.3 Locations
of Impact Noise Monitoring Stations
Monitoring Station
|
Location
|
NMS5
|
Ma Wan Chung
Village (Ma Wan Chung Resident Association) (Tung Chung)
|
3.4.1 Table 3.4
summarizes the monitoring parameters, frequency and duration of impact noise
monitoring.
Table 3.4 Noise
Monitoring Parameters, Frequency and Duration
Parameter
|
Frequency and Duration
|
30-mins
measurement at each monitoring station between 0700 and 1900 on normal
weekdays (Monday to Saturday). Leq, L10
and L90 would be recorded.
|
At least once
per week
|
3.5.1 Monitoring
Procedure
(a) The sound level
meter was set on a tripod at a height of 1.2 m above the podium for free-field measurements at NMS5. A correction of +3 dB(A)
shall be made to the free field measurements.
(b) The battery
condition was checked to ensure the correct functioning of the meter.
(c)
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: Leq(30-minutes) during non-restricted
hours i.e. 07:00 ¡V 1900 on normal weekdays
(e) Prior to and
after each noise measurement, the meter was calibrated using the acoustic
calibrator for 94.0 dB(A) at 1000 Hz. If the difference in the calibration
level before and after measurement was more than 1.0 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 on a
standard record sheet.
(g) Noise
measurement was paused during periods of high intrusive noise (e.g. dog
barking, helicopter noise) if possible. Observations were recorded when
intrusive noise was unavoidable.
(h) Noise monitoring
was cancelled in the presence of fog, rain, wind with a steady speed exceeding 5m/s, or wind with gusts exceeding 10m/s. The wind speed shall be checked with a
portable wind speed meter capable of measuring the wind speed in m/s.
3.5.2 Maintenance
and Calibration
(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 calibrators are provided in
Appendix C.
3.6.1 The
schedule for construction noise monitoring in October 2015 is provided in Appendix D.
3.7.1 The
monitoring results for construction noise are summarized in Table 3.5 and the monitoring results
and relevant graphical plots are provided in Appendix E.
Table 3.5 Summary
of Construction Noise Monitoring Results During the Reporting Month
Monitoring Station
|
Average Leq
(30 mins), dB(A)
|
Range of Leq
(30 mins), dB(A)
|
Limit Level Leq
(30 mins), dB(A)
|
NMS5
|
56
|
55 ¡V 58
|
75
|
*A correction factor of +3dB(A) from free
field to facade measurement was included.
3.7.2
There were no Action and Limit Level exceedances for noise during
daytime on normal weekdays of the reporting month.
3.7.3 Major
noise sources during the noise monitoring included construction activities of
the Contract, nearby traffic and insect noise.
3.7.4 The event
action plan is annexed in Appendix F.
4
Water Quality Monitoring
4.1.1 Impact
water quality monitoring was carried out to ensure that any deterioration of
water quality is detected, and that timely action is taken to rectify the
situation. For impact water quality
monitoring, measurements were taken in accordance with the Contract Specific
EM&A Manual. Table 4.1 shows the
established Action/Limit Levels for the environmental monitoring works. The ET proposed to amend the Acton Level
and Limit Level for turbidity and suspended solid and EPD approved ET¡¦s
proposal on 25 March 2013.
Therefore, Action Level and Limit Level for the Contract have been
changed since 25 March 2013.
4.1.2 The
original and revised Action Level and Limit Level for turbidity and suspended
solid are shown in Table 4.1.
Table 4.1 Action
and Limit Levels for Water Quality
Parameter (unit)
|
Water Depth
|
Action Level
|
Limit Level
|
Dissolved
Oxygen (mg/L) (surface, middle and bottom)
|
Surface and
Middle
|
5.0
|
4.2 except 5
for Fish Culture Zone
|
Bottom
|
4.7
|
3.6
|
Turbidity
(NTU)
|
Depth average
|
27.5 or 120%
of upstream control station¡¦s turbidity at the same tide of the same day;
The action
level has been amended to ¡§27.5 and 120% of upstream control
station¡¦s turbidity at the same tide of the same day¡¨ since 25 March 2013.
|
47.0 or 130%
of turbidity at the upstream control station at the same tide of same day;
The limit
level has been amended to ¡§47.0 and 130% of turbidity at the
upstream control station at the same tide of same day¡¨ since 25 March 2013.
|
Suspended
Solid (SS) (mg/L)
|
Depth average
|
23.5 or 120%
of upstream control station¡¦s SS at the same tide of the same day;
The action
level has been amended to ¡§23.5 and 120% of upstream control
station¡¦s SS at the same tide of the same day¡¨ since 25 March 2013.
|
34.4 or 130%
of SS at the upstream control station at the same tide of same day and 10mg/L
for Water Services Department Seawater Intakes;
The limit
level has been amended to ¡§34.4 and 130% of SS at the upstream
control station at the same tide of same day and 10mg/L for Water Services
Department Seawater Intakes¡¨ since 25 March 2013
|
Notes:
(1) Depth-averaged
is calculated by taking the arithmetic means of reading of all three depths.
(2) For DO,
non-compliance of the water quality limit occurs when monitoring result is
lower that the limit.
(3) For SS
& turbidity non-compliance of the water quality limits occur when
monitoring result is higher than the limits.
(4) The change
to the Action and limit Levels for Water Quality Monitoring for the EM&A
works was approved by EPD on 25 March 2013.
4.2.1 Table 4.2
summarises the equipment used in the impact water quality monitoring programme.
Table 4.2 Water
Quality Monitoring Equipment
Equipment
|
Brand and Model
|
DO and
Temperature Meter, Salinity Meter, Turbidimeter and
pH Meter
|
YSI Model 6820
V2-M, 650
|
Positioning
Equipment
|
DGPS ¡V KODEN :
KGP913MkII, KBG3
|
Water Depth
Detector
|
Layin Associates: SM-5 & SM5A
|
Water Sampler
|
Wildlife
Supply Company : 5487-10
|
4.3.1
Table 4.3 summarises the
monitoring parameters, frequency and monitoring depths of impact water quality
monitoring as required in the Contract Specific EM&A Manual.
Table 4.3 Impact
Water Quality Monitoring Parameters and Frequency
Monitoring Stations
|
Parameter, unit
|
Frequency
|
No. of depth
|
Impact Stations:
IS5, IS(Mf)6, IS7, IS8, IS(Mf)9
& IS10,
Control/Far Field
Stations:
CS2 & CS(Mf)5,
Sensitive Receiver
Stations:
SR3, SR4, SR5, SR10A &
SR10B
|
¡P
Depth, m
¡P
Temperature, oC
¡P
Salinity, ppt
¡P
Dissolved Oxygen
(DO), mg/L
¡P
DO Saturation, %
¡P
Turbidity, NTU
¡P
pH
¡P Suspended Solids (SS), mg/L
|
Three times per week
during mid-ebb and mid-flood tides (within ¡Ó 1.75 hour of the predicted time)
|
3
(1 m below water surface,
mid-depth and 1 m above sea bed, except where the water depth is less than 6
m, in which case the mid-depth station may be omitted. Should the water
depth be less than 3 m, only the mid-depth station will be monitored).
|
4.4.1 In
accordance with the Contract Specific EM&A Manual, thirteen stations (6 Impact
Stations, 5
Sensitive Receiver Stations and 2 Control
Stations) were designated for impact water quality monitoring. The six Impact
Stations (IS) were chosen on the basis of their proximity to the reclamation
and thus the greatest potential for water quality impacts, the five
Sensitive Receiver Stations (SR) were chosen as they are close to the key
sensitive receives and the two Control Stations (CS) were chosen to facilitate
comparison of the water quality of the IS stations with less influence by the
Project/ ambient water quality conditions.
4.4.2 The
locations of these monitoring stations are summarized in Table 4.4 and shown in
Figure 2.1.
Table 4.4 Impact
Water Quality Monitoring Stations
Monitoring Stations
|
Description
|
Coordinates
|
Easting
|
Northing
|
IS5
|
Impact Station
(Close to HKLR construction site)
|
811579
|
817106
|
IS(Mf)6
|
Impact Station
(Close to HKLR construction site)
|
812101
|
817873
|
IS7
|
Impact Station
(Close to HKBCF construction site)
|
812244
|
818777
|
IS8
|
Impact Station
(Close to HKBCF construction site)
|
814251
|
818412
|
IS(Mf)9
|
Impact Station
(Close to HKBCF construction site)
|
813273
|
818850
|
IS10
|
Impact Station
(Close to HKBCF construction site)
|
812577
|
820670
|
SR3
|
Sensitive
receivers (San Tau SSSI)
|
810525
|
816456
|
SR4
|
Sensitive
receivers (Tai Ho Inlet)
|
814760
|
817867
|
SR5
|
Sensitive
receivers (Artificial Reef In NE Airport)
|
811489
|
820455
|
SR10A
|
Sensitive
receivers (Ma Wan Fish Culture Zone)
|
823741
|
823495
|
SR10B
|
Sensitive
receivers (Ma Wan Fish Culture Zone)
|
823686
|
823213
|
CS2
|
Control
Station (Mid-Ebb)
|
805849
|
818780
|
CS(Mf)5
|
Control
Station (Mid-Flood)
|
817990
|
821129
|
4.5
Monitoring Methodology
4.5.1 Instrumentation
(a) The
in-situ water quality parameters including dissolved oxygen, temperature, salinity
and turbidity, pH were measured by multi-parameter meters.
4.5.2 Operating/Analytical
Procedures
(a) Digital Differential Global Positioning
Systems (DGPS) were used to ensure that the correct location was selected prior
to sample collection.
(b) Portable, battery-operated echo sounders
were used for the determination of water depth at each designated monitoring
station.
(c) All in-situ measurements were taken at 3
water depths, 1 m below water surface, mid-depth and 1 m above sea bed, except
where the water depth was less than 6 m, in which case the mid-depth station
was omitted. Should the water depth be less than 3 m, only the mid-depth
station was monitored.
(d) At each measurement/sampling depth, two
consecutive in-situ monitoring (DO concentration and saturation, temperature,
turbidity, pH, salinity) and water sample for SS. The probes were retrieved out
of the water after the first measurement and then re-deployed for the second
measurement. Where the difference in the value between the first and second
readings of DO or turbidity parameters was more than 25% of the value of the
first reading, the reading was discarded and further readings were taken.
(e) Duplicate samples from each independent
sampling event were collected for SS measurement. Water samples were collected
using the water samplers and the samples were stored in high-density polythene
bottles. Water samples collected were well-mixed in the water sampler prior to
pre-rinsing and transferring to sample bottles. Sample bottles were pre-rinsed
with the same water samples. The sample bottles were then be packed in
cool-boxes (cooled at 4oC without being frozen), and delivered to
ALS Technichem (HK) Pty Ltd. for the analysis of
suspended solids concentrations. The laboratory determination work would be
started within 24 hours after collection of the water samples. ALS Technichem (HK) Pty Ltd. is a HOKLAS accredited laboratory
and has comprehensive quality assurance and quality control programmes.
(f) The analysis method and detection limit for
SS is shown in Table 4.5.
Table 4.5 Laboratory Analysis for Suspended Solids
Parameters
|
Instrumentation
|
Analytical Method
|
Detection Limit
|
Suspended
Solid (SS)
|
Weighting
|
APHA 2540-D
|
0.5mg/L
|
(g) Other relevant data were recorded, including
monitoring location / position, time, water depth, tidal stages, weather
conditions and any special phenomena or work underway at the construction site
in the field log sheet for information.
4.5.3 Maintenance
and Calibrations
(a) All in situ monitoring
instruments would be calibrated by ALS Technichem
(HK) Pty Ltd. before use and at 3-monthly intervals throughout all stages of
the water quality monitoring programme. The
procedures of performance check of sonde and testing
results are provided in Appendix C.
4.6.1 The
schedule for impact water quality monitoring in October 2015 is provided in Appendix D.
4.7.1 Impact
water quality monitoring was conducted at all designated monitoring stations
during the reporting month. Impact water quality monitoring results and
relevant graphical plots are provided in
Appendix E.
4.7.2 Number of
exceedances recorded during the reporting month at each impact station are
summarised in Table 4.6.
Table 4.6 Summary
of Water Quality Exceedances
Station
|
Exceedance Level
|
DO
(S&M)
|
DO
(Bottom)
|
Turbidity
|
SS
|
Total number of exceedances
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
IS5
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS(Mf)6
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS7
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS8
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS(Mf)9
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS10
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR3
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR4
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
11
Sep 2015
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR5
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR10A
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR10B
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Total
|
Action
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
1**
|
Limit
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0**
|
Notes:
S: Surface;
M: Mid-depth;
** The total number of exceedances
4.7.1 For marine water quality monitoring, one
Action Level exceedances of suspended solid level were recorded during
the reporting month. No Limit Level exceedance of suspended solid level was recorded. No
Action Level/ Limit Level exceedance of turbidity level and dissolved oxygen level were recorded during the
reporting month.
4.7.2
The construction
activities on 11 September 2015 were carried out within silt curtain as
recommended in the EIA Report. There were no specific activities
recorded during the monitoring period that
would cause any significant impacts on the monitoring results. The exceedance
of suspended solid level was considered to be
attributed to other external factors, rather than the contract works.
Therefore, the exceedance was
considered as non-contract related. Record of ¡§Notification of Environmental Quality Limit Exceedances¡¨ is
provided in Appendix N.
4.7.1
Water quality impact
sources during water quality monitoring were the construction activities of the
Contract, nearby construction activities by other parties and
nearby operating vessels by other parties.
4.7.2
The event action plan
is annexed in Appendix F.
5.1.1 Impact
dolphin monitoring is required to be
conducted by a qualified dolphin specialist team to evaluate whether there have been any effects on the dolphins.
5.1.2
The Action Level and Limit Level for dolphin
monitoring are shown in Table 5.1.
Table 5.1 Action
and Limit Levels for Dolphin Monitoring
|
North Lantau Social Cluster
|
NEL
|
NWL
|
Action Level
|
STG < 4.2 & ANI < 15.5
|
STG < 6.9
& ANI < 31.3
|
Limit Level
|
(STG < 2.4
& ANI < 8.9) and (STG < 3.9 & ANI < 17.9)
|
Remarks:
1. STG means quarterly encounter rate of number of dolphin sightings.
2. ANI means quarterly encounter rate of total number of dolphins.
3. For North Lantau Social Cluster, AL will be trigger if either NEL or NWL fall below the criteria; LL will
be triggered if both NEL and NWL
fall below the criteria.
5.1.3
The revised Event and Action
Plan for dolphin Monitoring was approved by EPD in 6 May 2013. The revised
Event and Action Plan is annexed in Appendix F.
Vessel-based Line-transect Survey
5.2.1 According to the requirements of
the Updated EM&A Manual for HKLR (Version 1.0), dolphin monitoring programme should cover all transect lines in NEL and NWL
survey areas (see Figure 1 of Appendix H)
twice per month. The co-ordinates of all transect lines are shown in Table 5.2. The coordinates of several
starting points have been revised due to the obstruction of the permanent
structures associated with the construction works of HKLR and the southern
viaduct of TM-CLKL, as well as provision of adequate buffer distance from the
Airport Restricted Areas. The EPD issued a memo and
confirmed that they had no objection on the revised transect lines on 19 August 2015, and the revised coordinates are in red and marked with
an asterisk in Table 5.2.
Table 5.2 Co-ordinates
of Transect Lines
Line No.
|
Easting
|
Northing
|
|
Line No.
|
Easting
|
Northing
|
1
|
Start Point
|
804671
|
815456*
|
|
13
|
Start Point
|
816506
|
819480
|
1
|
End Point
|
804671
|
831404
|
|
13
|
End Point
|
816506
|
824859
|
2
|
Start Point
|
805475
|
815913*
|
|
14
|
Start Point
|
817537
|
820220
|
2
|
End Point
|
805477
|
826654
|
|
14
|
End Point
|
817537
|
824613
|
3
|
Start Point
|
806464
|
819435
|
|
15
|
Start Point
|
818568
|
820735
|
3
|
End Point
|
806464
|
822911
|
|
15
|
End Point
|
818568
|
824433
|
4
|
Start Point
|
807518
|
819771
|
|
16
|
Start Point
|
819532
|
821420
|
4
|
End Point
|
807518
|
829230
|
|
16
|
End Point
|
819532
|
824209
|
5
|
Start Point
|
808504
|
820220
|
|
17
|
Start Point
|
820451
|
822125
|
5
|
End Point
|
808504
|
828602
|
|
17
|
End Point
|
820451
|
823671
|
6
|
Start Point
|
809490
|
820466
|
|
18
|
Start Point
|
821504
|
822371
|
6
|
End Point
|
809490
|
825352
|
|
18
|
End Point
|
821504
|
823761
|
7
|
Start Point
|
810499
|
820880*
|
|
19
|
Start Point
|
822513
|
823268
|
7
|
End Point
|
810499
|
824613
|
|
19
|
End Point
|
822513
|
824321
|
8
|
Start Point
|
811508
|
821123*
|
|
20
|
Start Point
|
823477
|
823402
|
8
|
End Point
|
811508
|
824254
|
|
20
|
End Point
|
823477
|
824613
|
9
|
Start Point
|
812516
|
821303*
|
|
21
|
Start Point
|
805476
|
827081
|
9
|
End Point
|
812516
|
824254
|
|
21
|
End Point
|
805476
|
830562
|
10
|
Start Point
|
813525
|
820872
|
|
22
|
Start Point
|
806464
|
824033
|
10
|
End Point
|
813525
|
824657
|
|
22
|
End Point
|
806464
|
829598
|
11
|
Start Point
|
814556
|
818853*
|
|
23
|
Start Point
|
814559
|
821739
|
11
|
End Point
|
814556
|
820992
|
|
23
|
End Point
|
814559
|
824768
|
12
|
Start Point
|
815542
|
818807
|
|
|
|
|
|
12
|
End Point
|
815542
|
824882
|
|
|
|
|
|
Note:
Co-ordinates in red and marked with asterisk are revised co-ordinates of
transect line.
5.2.2 The
survey team used standard line-transect methods (Buckland et al. 2001) to
conduct the systematic vessel surveys, and followed the same technique of data collection
that has been adopted over the last 16 years of marine mammal monitoring
surveys in Hong Kong developed by HKCRP (see Hung 2012, 2013). For each monitoring vessel survey, a
15-m inboard vessel with an open upper deck (about 4.5 m above water surface)
was used to make observations from the flying bridge area.
5.2.3 Two
experienced observers (a data recorder and a primary observer) made up the
on-effort survey team, and the survey vessel transited different transect lines
at a constant speed of 13-15 km per hour.
The data recorder searched with unaided eyes and filled out the
datasheets, while the primary observer searched for dolphins and porpoises
continuously through 7 x 50 Fujinon marine
binoculars. Both observers searched
the sea ahead of the vessel, between 270o and 90o (in
relation to the bow, which is defined as 0o). One to two additional experienced
observers were available on the boat to work in shift (i.e. rotate every 30
minutes) in order to minimize fatigue of the survey team members. All observers were experienced in small
cetacean survey techniques and identifying local cetacean species.
5.2.4 During
on-effort survey periods, the survey team recorded effort data including time,
position (latitude and longitude), weather conditions (Beaufort sea state and
visibility), and distance travelled in each series (a continuous period of
search effort) with the assistance of a handheld GPS (Garmin eTrex Legend).
5.2.5 Data
including time, position and vessel speed were also automatically and
continuously logged by handheld GPS throughout the entire survey for subsequent
review.
5.2.6 When
dolphins were sighted, the survey team would end the survey effort, and
immediately record the initial sighting distance and angle of the dolphin group
from the survey vessel, as well as the sighting time and position. Then the research vessel was diverted
from its course to approach the animals for species identification, group size
estimation, assessment of group composition, and behavioural
observations. The perpendicular
distance (PSD) of the dolphin group to the transect line was later calculated
from the initial sighting distance and angle.
5.2.7 Survey
effort being conducted along the parallel transect lines that were
perpendicular to the coastlines (as indicated in Figure 1 of Appendix H) was labeled as ¡§primary¡¨ survey effort,
while the survey effort conducted along the connecting lines between parallel
lines was labeled as ¡§secondary¡¨ survey effort. According to HKCRP long-term dolphin
monitoring data, encounter rates of Chinese white dolphins deduced from effort
and sighting data collected along primary and secondary lines were similar in
NEL and NWL survey areas.
Therefore, both primary and secondary survey effort were presented as on-effort
survey effort in this report.
5.2.8 Encounter
rates of Chinese White Dolphins (number of on-effort sightings per 100 km of
survey effort and number of dolphins from all on-effort sightings per 100 km of
survey effort) were calculated in NEL and NWL survey areas in relation to the
amount of survey effort conducted during each month of monitoring survey. Only data collected under Beaufort 3 or
below condition would be used for encounter rate analysis. Dolphin encounter rates were calculated
using primary survey effort alone, as well as the combined survey effort from
both primary and secondary lines.
Photo-identification Work
5.2.9 When a
group of Chinese White Dolphins were sighted during the line-transect survey,
the survey team would end effort and approach the group slowly from the side
and behind to take photographs of them.
Every attempt was made to photograph every dolphin in the group, and
even photograph both sides of the dolphins, since the colouration
and markings on both sides may not be symmetrical.
5.2.10 A
professional digital cameras (Canon EOS 7D and 60D models), equipped with long
telephoto lenses (100-400 mm zoom), were available on board for researchers to
take sharp, close-up photographs of dolphins as they surfaced. The images were shot at the highest
available resolution and stored on Compact Flash memory cards for downloading
onto a computer.
5.2.11 All
digital images taken in the field were first examined, and those containing
potentially identifiable individuals were sorted out. These photographs would then be examined
in greater detail, and were carefully compared to the existing Chinese White
Dolphin photo-identification catalogue maintained by HKCRP since 1995.
5.2.12 Chinese
White Dolphins can be identified by their natural markings, such as nicks,
cuts, scars and deformities on their dorsal fin and body, and their unique
spotting patterns were also used as secondary identifying features (Jefferson
2000).
5.2.13 All
photographs of each individual were then compiled and arranged in chronological
order, with data including the date and location first identified (initial
sighting), re-sightings, associated dolphins, distinctive features, and age
classes entered into a computer database.
Detailed information on all identified individuals will be further
presented as an appendix in quarterly EM&A reports.
Vessel-based Line-transect Survey
5.3.1 During the month of September 2015, two sets of
systematic line-transect vessel surveys were conducted on 2nd, 11th, 17th
and 29th to cover all
transect lines in NWL and NEL survey areas twice. The survey routes of each
survey day are presented in Figures 2 to
5 of Appendix H.
5.3.2 From these surveys, a total
of 303.46
km of survey effort was collected, with 99.0% of the total survey effort being conducted under
favourable weather conditions (i.e. Beaufort Sea State 3 or below with good
visibility) (Annex I of Appendix H). Among the two areas, 115.34
km and 188.12
km of survey effort were collected from
NEL and NWL survey areas respectively.
Moreover,
the total survey effort conducted on primary lines was
221.51 km, while the effort on secondary lines
was 81.95
km.
5.3.3 During the two sets of monitoring surveys in
September 2015, seven groups
of 54 Chinese
White Dolphins were sighted. (Annex II of
Appendix H). All seven
dolphin sightings were made in NWL, while none was sighted at all in NEL.
5.3.4 During September¡¦s surveys, all
seven dolphin sightings
were made on primary lines during
on-effort search.
One of the dolphin groups was associated with an operating
purse-seiner near Lung Kwu
Chau.
5.3.5 Distribution of these dolphin sightings made in September 2015 is shown in Figure
6 of Appendix H. Six
of the seven dolphin groups were clustered near Lung Kwu
Chau or to the north of the island, while another sighting was made to the west
of Sha Chau (Figure 6 of
Appendix H).
5.3.6 Notably none of the dolphin sightings were located
in the proximity of the HKLR03 and HKBCF reclamation sites, as well as the
HKLR09 and TMCLKL alignments (Figure 6 of Appendix H).
5.3.7 During
the September¡¦s surveys, encounter rates of Chinese White Dolphins deduced from
the survey effort and on-effort sighting data made under favourable
conditions (Beaufort 3 or below) are shown in Table 5.3 and Table
5.4.
5.3.8
The average group size of Chinese White Dolphins in September 2015 was
only 7.7 individuals per group, which was exceptionally high when compared to
previous months of monitoring surveys.
Among the seven groups, five of them were composed of 4-8 dolphins,
while there were two large groups with 12 dolphins respectively.
Table 5.3 Individual Survey Event Encounter Rates
|
Encounter rate (STG)
(no. of on-effort
dolphin sightings per 100 km of survey effort)
|
Encounter rate (ANI)
(no. of dolphins from
all on-effort sightings per 100 km of survey effort)
|
Primary Lines Only
|
Primary Lines Only
|
NEL
|
Set 1: September 2nd / 11th
|
0.0
|
0.0
|
Set 2: September 17th / 29th
|
0.0
|
0.0
|
NWL
|
Set 1: September 2nd / 11th
|
5.5
|
52.0
|
Set 2: September 17th / 29th
|
4.0
|
21.4
|
Remarks:
1. Dolphin Encounter Rates Deduced from the Two
Sets of Surveys (Two Surveys in Each Set) in September 2015 in Northeast (NEL) and Northwest Lantau
(NWL).
Table 5.4 Monthly
Average Encounter Rates
|
Encounter
rate (STG)
(no. of on-effort
dolphin sightings per 100 km of survey effort)
|
Encounter rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey
effort)
|
Primary Lines Only
|
Both Primary and
Secondary Lines
|
Primary Lines Only
|
Both Primary and
Secondary Lines
|
Northeast Lantau
|
0.0
|
0.0
|
0.0
|
0.0
|
Northwest Lantau
|
4.7
|
3.7
|
36.5
|
28.7
|
Remarks:
1.
Monthly Average Dolphin Encounter Rates (Sightings Per 100 km of
Survey Effort) from All Four Surveys Conducted in September 2015 on Primary Lines only as well as Both
Primary Lines and Secondary Lines in Northeast (NEL) and Northwest Lantau
(NWL).
Photo-identification Work
5.3.9
Twenty-three individual dolphins were sighted 33 times during
September¡¦s surveys (Annex III and IV of Appendix H). The majority of individuals were
sighted only once during the monitoring month, but there were also six
individuals being sighted twice and two individuals being sighted thrice.
5.3.10
Notably, three individuals (NL202, NL233
and NL297) were accompanied with calves during their re-sightings.
Conclusion
5.3.11
During this month of dolphin
monitoring, no adverse impact from the activities of this construction project
on Chinese White Dolphins was noticeable from general observations.
5.3.12 Due to monthly variation in dolphin occurrence within the study
area, it would be more appropriate to draw conclusion on whether any impacts on
dolphins have been detected related to the construction activities of this
project in the quarterly EM&A report, where comparison on distribution,
group size and encounter rates of dolphins between the quarterly impact
monitoring period (September ¡V November 2015)
and baseline monitoring period (3-month period) will be made.
5.4.1
Buckland, S. T., Anderson, D. R., Burnham,
K. P., Laake, J. L., Borchers,
D. L., and Thomas, L. 2001. Introduction to distance sampling:
estimating abundance of biological populations. Oxford University Press, London.
5.4.2
Hung, S. K. 2012. Monitoring of Marine Mammals in Hong
Kong waters: final report (2011-12).
An unpublished report submitted to the Agriculture, Fisheries and
Conservation Department, 171 pp.
5.4.3
Hung, S. K. 2013. Monitoring of Marine Mammals in Hong Kong waters: final report (2012-13). An unpublished report submitted to the
Agriculture, Fisheries and Conservation Department, 168 pp.
5.4.4
Jefferson, T. A. 2000. Population biology of the Indo-Pacific
hump-backed dolphin in Hong Kong waters.
Wildlife Monographs 144:1-65.
Methodology
6.1.1 To avoid
disturbance to the mudflat and nuisance to navigation, no fixed
marker/monitoring rod was installed at the monitoring stations. A high
precision Global Navigation Satellite System (GNSS) real time location fixing
system (or equivalent technology) was used to locate the station in the
precision of 1mm, which is reasonable under flat mudflat topography with uneven
mudflat surface only at micro level.
This method has been used on Agricultural Fisheries and Conservation
Department¡¦s (AFCD) project, namely Baseline Ecological Monitoring Programme
for the Mai Po Inner Deep Bay Ramsar Site for
measurement of seabed levels.
6.1.2 Measurements
were taken directly on the mudflat surface. The Real Time Kinematic GNSS (RTK GNSS)
surveying technology was used to measure mudflat surface levels and 3D
coordinates of a survey point. The
RTK GNSS survey was calibrated against a reference station in the field before
and after each survey. The
reference station is a survey control point established by the Lands Department
of the HKSAR Government or traditional land surveying methods using
professional surveying instruments such as total station, level and/or geodetic
GNSS. The coordinates system was in
HK1980 GRID system. For this contract,
the reference control station was surveyed and established by traditional land
surveying methods using professional surveying instruments such as total
station, level and RTK GNSS. The
accuracy was down to mm level so that the reference control station has
relatively higher accuracy. As the
reference control station has higher accuracy, it was set as true evaluation
relative to the RTK GNSS measurement.
All position and height correction were adjusted and corrected to the
reference control station. Reference
station survey result and professional land surveying calibration is shown as Table 6.1:
Table 6.1 Reference
Station Survey result and GNSS RTK calibration result of Round 1
Reference
Station
|
Easting
(m)
|
Northing
(m)
|
Baseline
reference elevation (mPD) (A)
|
Round
1 Survey (mPD) (B)
|
Calibration
Adjustment (B-A)
|
T1
|
811248.660mE
|
816393.173mN
|
3.840
|
3.817
|
-0.023
|
T2
|
810806.297mE
|
815691.822mN
|
4.625
|
4.653
|
+0.028
|
T3
|
810778.098mE
|
815689.918mN
|
4.651
|
4.660
|
+0.009
|
T4
|
810274.783mE
|
816689.068mN
|
2.637
|
2.709
|
+0.072
|
6.1.3 The
precision of the measured mudflat surface level reading (vertical precision
setting) was within 10 mm (standard deviation) after averaging the valid survey
records of the XYZ HK1980 GRID coordinates. Each survey record at each station was
computed by averaging at least three measurements that are within the above
specified precision setting. Both digital data logging and written records were
collected in the field. Field data
on station fixing and mudflat surface measurement were recorded.
Monitoring Locations
6.1.4 Four
monitoring stations were established based on the site conditions for the
sedimentation monitoring and are shown in Figure
6.1.
Monitoring Results
6.1.5 The
baseline sedimentation rate monitoring was in September 2012 and impact
sedimentation rate monitoring was undertaken on 14
June 2015. The mudflat surface levels at the four
established monitoring stations and the corresponding XYZ HK1980 GRID
coordinates are presented in Table 6.2
and Table 6.3.
Table 6.2 Measured
Mudflat Surface Level Results
|
Baseline
Monitoring (September 2012)
|
Impact Monitoring (September 2015)
|
Monitoring Station
|
Easting (m)
|
Northing (m)
|
Surface Level
(mPD)
|
Easting (m)
|
Northing (m)
|
Surface Level
(mPD)
|
S1
|
810291.160
|
816678.727
|
0.950
|
810291.167
|
816678.723
|
1.061
|
S2
|
810958.272
|
815831.531
|
0.864
|
810958.278
|
815831.542
|
0.960
|
S3
|
810716.585
|
815953.308
|
1.341
|
810716.595
|
815953.340
|
1.466
|
S4
|
811221.433
|
816151.381
|
0.931
|
811221.414
|
816151.336
|
1.004
|
Table 6.3 Comparison
of measurement
|
Comparison
of measurement
|
Remarks and Recommendation
|
Monitoring
Station
|
Easting
(m)
|
Northing
(m)
|
Surface
Level
(mPD)
|
S1
|
0.007
|
-0.004
|
0.111
|
Level continuously
increased
|
S2
|
0.006
|
0.011
|
0.096
|
Level continuously increased
|
S3
|
0.010
|
0.032
|
0.125
|
Level continuously
increased
|
S4
|
-0.019
|
-0.045
|
0.073
|
Level continuously
increased
|
6.1.6 This measurement result was
generally and relatively higher than the baseline measurement at S1, S2, S3 and
S4. The mudflat level is continuously increased.
6.2.1 The
mudflat monitoring covered water quality monitoring data. Reference was made to the water quality
monitoring data of the representative water quality monitoring station (i.e.
SR3) as in the EM&A Manual. The
water quality monitoring location (SR3) is shown in Figure 2.1.
6.2.2 Impact
water quality monitoring in San Tau (monitoring station SR3) was conducted in
June 2015. The monitoring parameters
included dissolved oxygen (DO), turbidity and suspended solids (SS).
6.2.3 The
Impact monitoring results for SR3 were extracted and summarised below:
Table 6.4 Impact
Water Quality Monitoring Results (Depth Average)
Date
|
Mid Ebb
Tide
|
Mid Flood
Tide
|
DO (mg/L)
|
Turbidity
(NTU)
|
SS (mg/L)
|
DO (mg/L)
|
Turbidity
(NTU)
|
SS (mg/L)
|
2-Sep-15
|
5.69
|
20.40
|
8.30
|
5.46
|
15.85
|
13.50
|
4-Sep-15
|
6.27
|
7.55
|
7.35
|
6.22
|
4.40
|
4.60
|
7-Sep-15
|
6.32
|
3.75
|
3.30
|
6.43
|
4.75
|
5.80
|
9-Sep-15
|
6.89
|
4.65
|
2.95
|
7.75
|
4.80
|
4.10
|
11-Sep-15
|
6.53
|
5.95
|
5.35
|
9.00
|
7.20
|
6.80
|
14-Sep-15
|
5.82
|
6.75
|
6.50
|
5.74
|
5.35
|
7.00
|
16-Sep-15
|
5.86
|
10.70
|
11.90
|
5.64
|
7.50
|
7.70
|
18-Sep-15
|
5.82
|
8.50
|
7.50
|
5.71
|
6.70
|
6.20
|
21-Sep-15
|
6.07
|
6.30
|
5.30
|
6.58
|
3.80
|
2.70
|
23-Sep-15
|
6.15
|
3.80
|
2.45
|
7.39
|
3.30
|
2.60
|
25-Sep-15
|
6.63
|
5.20
|
5.90
|
8.23
|
10.05
|
5.20
|
28-Sep-15
|
5.27
|
7.65
|
7.90
|
6.04
|
8.05
|
8.55
|
30-Sep-15
|
5.64
|
17.15
|
13.75
|
5.47
|
12.45
|
16.00
|
Average
|
6.07
|
8.33
|
6.80
|
6.59
|
7.25
|
6.98
|
Sampling Zone
6.3.1 In order to collect baseline information of mudflats in the study
site, the study site was divided into three sampling zones (labeled as TC1, TC2, TC3) in Tung Chung Bay
and one zone in San Tau (labeled as ST) (Figure 2.1 of Appendix I). The
horizontal length of sampling zones TC1, TC2, TC3 and ST
were about 250 m, 300 m, 300 m and 250 m, respectively. Survey of horseshoe
crabs, seagrass beds and intertidal communities were conducted in every
sampling zone. The present survey was conducted in September 2015 (totally 5 sampling
days between 5th and 13th September 2015).
Horseshoe Crabs
6.3.2 Active search method was conducted for horseshoe crab monitoring by two experienced surveyors at every sampling zone. During the search period, any accessible and potential area would
be investigated for any horseshoe crab individuals within 2-3 hours in low tide period (tidal level
below 1.2 m above Chart Datum (C.D.)). Once a horseshoe crab individual was found, the species was identified
referencing to Li (2008). The prosomal width, inhabiting substratum and respective GPS coordinate were recorded. A photographic
record was taken for future investigation. Any
grouping behavior of individuals, if found, was recorded. The horseshoe crab surveys were
conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th
(for TC2) September 2015. During the survey period, the weather was hot and
sunny in TC1, TC3 and ST while it was rainy in TC2.
Seagrass Beds
6.3.3 Active search method was conducted for seagrass
bed monitoring by two experienced surveyors at every sampling zone. During the search period, any accessible and potential area would
be investigated for any seagrass beds within 2-3 hours in low tide period. Once seagrass bed was found, the species, estimated area, estimated coverage percentage and respective GPS coordinate were recorded. A photographic
record was taken for future investigation. The seagrass beds surveys were
conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th
(for TC2) September 2015. During the survey period, the weather was hot and
sunny in TC1, TC3 and ST while it was rainy in TC2.
Intertidal Soft Shore Communities
6.3.4 The intertidal soft shore
community surveys were conducted in low tide period on 5th (for ST),
6th (for TC1), 12th (for TC2) and 13th September
2015 (for TC3). At each sampling zone, three 100 m horizontal transects were laid
at high tidal level (H: 2.0 m above C.D.), mid tidal level (M: 1.5 m above C.D.) and
low tidal level (L: 1.0 m above C.D.). Along every horizontal transect, ten random quadrats
(0.5 m x 0.5m) were placed.
6.3.5 Inside a quadrat, any visible epifauna were
collected and were in-situ identified to the lowest
practical taxonomical resolution. Whenever possible a hand core sample (10 cm internal diameter ´ 20 cm depth) of sediments was collected
in the quadrat. The core sample was gently washed through a sieve of mesh size
2.0 mm in-situ. Any visible infauna were collected and
identified. Finally the top 5 cm surface sediments were dug for visible infauna
in the quadrat regardless of hand core sample was taken.
6.3.6 All collected fauna were released after recording except some tiny
individuals that are too small to be identified on site. These
tiny individuals were taken to laboratory for identification under dissecting microscope.
6.3.7 The taxonomic classification was conducted in accordance to the
following references: Polychaetes: Fauchald
(1977), Yang and Sun (1988); Arthropods: Dai and Yang (1991), Dong (1991); Mollusks: Chan and Caley (2003),
Qi (2004).
Data Analysis
6.3.8
Data collected from direct search and core
sampling was pooled in every quadrat for data analysis. Shannon-Weaver
Diversity Index (H¡¦) and Pielou¡¦s Species Evenness
(J) were calculated for every quadrat using the formulae below,
H¡¦= -£U ( Ni / N ) ln
( Ni / N ) (Shannon and Weaver, 1963)
J = H¡¦
/ ln S, (Pielou, 1966)
where S is the total number of species in the
sample, N is the total number of individuals, and Ni is the number of
individuals of the ith species.
6.4.1
In the event of the impact monitoring results
indicating that the density or the distribution pattern of intertidal fauna and
seagrass is found to be significant different to the baseline condition (taking
into account natural fluctuation in the occurrence and distribution pattern
such as due to seasonal change), appropriate actions should be taken and
additional mitigation measures should be implemented as necessary. Data should then be re-assessed and the
need for any further monitoring should be established. The action plan, as given in Table 6.5 should be undertaken within a
period of 1 month after a significant difference has been determined.
Table
6.5 Event and
Action Plan for Mudflat Monitoring
Event
|
ET Leader
|
IEC
|
SO
|
Contractor
|
Density or the distribution pattern of
horseshoe crab, seagrass or intertidal soft shore communities recorded in the
impact or post-construction monitoring are significantly lower than or different
from those recorded in the baseline
monitoring.
|
Review historical data to ensure
differences are as a result of natural variation or previously observed
seasonal differences;
Identify source(s) of impact;
Inform the IEC, SO and Contractor;
Check monitoring data;
Discuss additional monitoring and any other
measures, with the IEC and Contractor.
|
Discuss monitoring with the ET and the
Contractor;
Review proposals for additional monitoring and
any other measures submitted by the Contractor and advise the SO accordingly.
|
Discuss with the IEC additional monitoring
requirements and any other measures proposed by the ET;
Make agreement on the measures to be
implemented.
|
Inform the SO and in writing;
Discuss with the ET and the IEC and propose
measures to the IEC and the ER;
Implement the agreed measures.
|
Notes:
ET ¡V Environmental Team
IEC ¡V Independent Environmental Checker
SO ¡V Supervising Officer
Horseshoe Crabs
6.5.1 In general, two species of horseshoe crab Carcinoscorpius rotundicauda
(total 196 ind.) and Tachypleus tridentatus (total 10 ind.) were recorded in the survey area. Individuals were
mainly found on fine sand while few were found on soft mud. The group size varied varied from 2 to 26 individuals for
every sight record. Although less number of Tachypleus tridentatus was recorded, the average body size was larger than that of Carcinoscorpius rotundicauda. Photo records were shown in Figure 3.1 of Appendix I while the complete
records of horseshoe crab survey in every sampling zone were shown in Annex II of Appendix I.
6.5.2 One big individual of Carcinoscorpius rotundicauda was found trapped in a trash
fish net (Figure 3.1 of Appendix I) on
ST shore (GPS coordinate: 22¢X 17.385' N, 113¢X 55.460' E). Its prosomal width
reached 130.77 mm. After photo recording, it was released to water. This big
individual should have had migrated to sub-tidal habitat. It might forage on
intertidal habitat occasionally during high tide period. Since intertidal soft
shore was no longer a nursery ground for this individual, its record was
excluded from the data analysis. It was to avoid mixing up with juvenile population living on soft shore.
6.5.3 Table 3.1 of
Appendix I summarizes the survey results of horseshoe crab in present survey. For Carcinoscorpius rotundicauda, it could be found in all sampling zones while more individuals were
recorded in TC3 and ST (TC1: 41 ind., TC2: 4 ind., TC3: 70 ind., ST: 81 ind.). The search record was 10.3 ind. hr-1 person-1, 1.0 ind. hr-1 person-1, 11.7 ind. hr-1 person-1,
13.5 ind. hr-1
person-1 in TC1, TC2, TC3 and ST respectively. The size of individuals was
similar among TC1 (mean prosomal width:
39.58 mm), TC2 (36.20 mm) and ST (37.03mm) while that of TC3 was smaller (27.27
mm).
6.5.4 For Tachypleus tridentatus, it could be found in TC3 (1 ind.) and ST (9 ind.) only. The search records were 0.2 ind. hr-1
person-1 and 1.5 ind. hr-1 person-1 in TC3 and ST respectively. The
mean prosomal
width of TC3 (53.90 mm) was
larger than that of ST (48.50mm).
6.5.5 In the previous survey of March
2015, there was one important finding that a mating pair of Carcinoscorpius rotundicauda was found in ST (prosomal width: male 155.1 mm, female 138.2 mm) (Figure 3.2 of Appendix I). It indicated the importance of ST as a breeding ground of horseshoe
crab. Moreover, two moults of Carcinoscorpius rotundicauda were found in TC1 with similar prosomal width 130-140 mm (Figure 3.2 of Appendix I). It reflected that a certain numbers of moderately sized individuals
inhabited the sub-tidal habitat of Tung Chung Wan after its nursery period on
soft shore. These individuals might move onto soft shore during high tide for
feeding, moulting and breeding. Then it would return
to sub-tidal habitat during low tide. Because the mating pair should be
inhabiting sub-tidal habitat in most of the time. The record was excluded from
the data analysis to avoid mixing up with juvenile population living on soft
shore.
6.5.6 No marked individual of horseshoe crab was recorded in present survey. Some marked
individuals were found in previous surveys conducted in September 2013, March
2014 and September 2014. All of them were released through a conservation programme conducted by Prof. Paul Shin (Department of
Biology and Chemistry, The City University of Hong Kong (CityU)).
It was a re-introduction trial of artificial bred horseshoe crab juvenile at
selected sites. So that the horseshoe crabs population might be restored in the
natural habitat. Through a personal conversation with Prof. Shin, about 100
individuals were released in the sampling zone ST on 20 June 2013. All of them
were marked with color tape and internal chip detected by specific chip sensor.
There should be second round of release between June and September 2014 since
new marked individuals were found in the survey of September 2014.
6.5.7 The artificial bred individuals, if found, would be excluded from the
results of present monitoring programme in order to
reflect the changes of natural population. However, the mark on their prosoma
might have been detached during moulting after a
certain period of release. The artificially released individuals were no longer
distinguishable from the natural population without the specific chip sensor.
The survey data collected would possibly cover both natural population and
artificially bred individuals.
Population difference among
the sampling zones
6.5.8 Figures 3.3 and 3.4 of Appendix I show the changes of number of individuals, mean prosomal width and search record of
horseshoe crabs Carcinoscorpius rotundicauda
and Tachypleus tridentatus respectively in every sampling
zone along the sampling months. In general, higher search records (i.e. number of individuals)
of both species were always found in ST followed by TC3 from September 2012 to
September 2014. Then the search record in TC3 was even higher than that in ST
from March 2015 to June 2015. In this sampling month (Sep. 2015), highest
search record was found in ST again. For TC1, the search record was at low to
medium level and fluctuated slightly along the sampling months. In
contrast, much lower search record was found in TC2 (2 ind.
in September 2013, 1 ind. in March, June, September.
2014, March and June 2015, 4 ind. in September.
2015). For spatial difference of horseshoe crab size, larger individuals were
usually found in ST while smaller individuals were usually found in TC3.
6.5.9
Throughout the monitoring period conducted, it was obvious that TC3 and ST (western
shore of Tung Chung Wan) was an important nursery ground for horseshoe crab
especially newly hatched individuals due to larger area of suitable substratum
(fine sand or soft mud) and less human disturbance (far from urban district).
Relatively, other sampling zones were not a suitable nursery ground especially
TC2. Possible factors were less area of suitable substratum (especially TC1)
and higher human disturbance (TC1 and TC2: close to urban district and easily
accessible). In TC2, large daily salinity fluctuation was a possible factor either
since it was flushed by two rivers under tidal inundation. The individuals
inhabiting TC1 and TC2 were confined in small moving range due to limited area
of suitable substrata during the nursery period.
Seasonal
variation of horseshoe crab population
6.5.10
Throughout the monitoring period conducted, the search record of
horseshoe crab declined obviously during dry season especially December (Figures 3.3 and 3.4 of Appendix I). In December 2013, no
individual of horseshoe crab was found. In December 2014, 2 individuals
of Carcinoscorpius rotundicauda and 8 individuals of Tachypleus tridentatus were found only. The horseshoe crabs were inactive
and burrowed in the sediments during cold weather (<15 ºC). Similar results of low search record in dry season were reported in a
previous territory-wide survey of horseshoe crab. For example, the search
records in Tung Chung Wan were 0.17 ind. hr-1 person-1 and 0.00 ind. hr-1 person-1 in wet season and dry season respectively (details see Li, 2008). After
the dry season, the search record increased with the warmer climate.
6.5.11
Between the sampling months September 2012 and December 2013, Carcinoscorpius rotundicauda
was a less common species relative to Tachypleus tridentatus. Only 4 individuals were ever
recorded in ST in December 2012. This species had ever been believed of very
low density in ST hence the encounter rate was very low. Since March. 2014, it
was found in all sampling zones with higher abundance in ST. Based on its
average size (mean prosomal width 39.28-49.81 mm), it indicated that breeding
and spawning of this species had occurred about 3 years ago along the coastline
of Tung Chun Wan. However, these individuals were still small while their
walking trails were inconspicuous. Hence there was no search record in previous
sampling months. From March 2014 to September 2015, more individuals were
recorded due to larger size and higher activity.
6.5.12
For Tachypleus tridentatus, sharp increase of
number of individuals was recorded in ST with wet season (from March to September
2013). According to a personal conversation with Prof. Shin (CityU), his monitoring team had recorded similar increase
of horseshoe crab population during wet season. It was believed that the
suitable ambient temperature increased its conspicuousness. However similar
pattern was not recorded during the wet season of 2014. The number of
individuals increased in March and June 2014 followed by a rapid decline in
September 2014. Then the number of individuals showed a general decreasing
trend from March. 2014 to June 2015. Apart from natural mortality, migration
from nursery soft shore to subtidal habitat was another possible cause. Since
the mean prosomal width of Tachypleus tridentatus continued to grow and reached
about 50 mm since March 2014. Then it varied slightly between 50-65 mm from
September 2014 to September 2015. Most of the individuals might have reached a
suitable size strong enough to forage in sub-tidal habitat.
6.5.13
Since TC3 and ST were regarded as important nursery ground for horseshoe
crab, box plots of prosomal width of two horseshoe crab species were
constructed to investigate the changes of population in details.
Box plot of horseshoe
crab populations in TC3
6.5.14
Figure 3.5 of Appendix I shows the changes of prosomal width of Carcinoscorpius rotundicauda and Tachypleus tridentatus in TC3. As mentioned above, Carcinoscorpius rotundicauda was rarely found between
September 2012 and December 2013 hence the data were lacking. In March 2014,
the major size (50% of
individual records between upper and lower quartile) ranged 40-60 mm while only
few individuals were found. From March 2014 to September 2015, the size of
major population decreased and more small individuals were recorded after March
of every year. It indicated new rounds of successful breeding and
spawning of Carcinoscorpius rotundicauda
in TC3. It matched with the previous mating record in ST in March 2015.
6.5.15
For Tachypleus tridentatus, the major size ranged
20-50 mm while the number of individuals found fluctuated from September 2012
to June 2014. Then a slight but consistent growing trend was observed. The
prosomal width increased from 25-35 mm in September 2014 to 35-65 mm in June
2015. As mentioned, the large individuals might have reached a suitable
size for migrating from the nursery soft shore to subtidal habitat. It
accounted for the declined population in TC3. In September 2015 (present
survey), there was only one individual recorded in TC3.
Box plot of horseshoe crab populations in ST
6.5.16 Figure 3.6 of Appendix I
shows the changes of
prosomal width of Carcinoscorpius rotundicauda and Tachypleus tridentatus in ST. As mentioned above, Carcinoscorpius rotundicauda was rarely found between
September 2012 and December 2013 hence the data were lacking. From Mar. 2014 to
Sep. 2015, the size of
major population decreased and more small individuals were recorded after Jun.
of every year. It indicated new rounds of successful breeding and
spawning of Carcinoscorpius rotundicauda
in ST. It matched with the previous mating record in ST in Mar. 2015. Because
the newly hatched individuals (prosomal width ~5mm) would take about half year
to grow to a size with conspicuous walking trail.
6.5.17 For Tachypleus tridentatus, a consistent growing
trend was observed for the major population from December 2012 to December 2014
regardless of change of search record. The prosomal width increased from 15-30
mm to 55-70 mm. As mentioned, the large individuals might have reached a
suitable size for migrating from the nursery soft shore to subtidal habitat.
From March to June 2015, the size of major population decreased slightly with
prosomal width 40-60 mm. It further indicated some of order individuals might
have migrated to sub-tidal habitat. From March to September 2015, the size of
major population decreased slightly to a prosomal width 40-60 mm. At the same
time, the number of individuals decreased gradually. It further indicated some
of large individuals might have migrated to sub-tidal habitats.
6.5.18 As a summary for horseshoe crab
populations in TC3 and ST, there was successful spawning of Carcinoscorpius rotundicauda
from 2014 to 2015. The spawning time should be in spring while the major
spawning month might be different slightly between two zones. There were
consistent, increasing trends of population size in these two sampling zones.
For Tachypleus tridentatus,
small individuals were rarely found TC3 and ST from 2014 to 2015. It was
believed no occurrence of successful spawning. The existing individuals (that
recorded since 2012) grew to a mature size and migrated to sub-tidal habitat.
Hence the number of individuals decreased gradually. It was expected the
population would remain at low level until new round of successful spawning.
Impact of the HKLR project
6.5.19 The present survey was the 12th
survey of the EM&A programme during the
construction period. Based on the results, impact of
the HKLR project could not be detected on horseshoe crabs considering the
factor of natural, seasonal variation. In
case, abnormal phenomenon (e.g. very few numbers of horseshoe crab individuals
in warm weather, large number of dead individuals on the shore)
is observed, it would be reported as soon as possible.
Seagrass Beds
6.5.20 In general, two species of
seagrass Halophila ovalis and Zostera japonica were
recorded in ST only. Both species were found on sandy substratum nearby the seaward side of
mangrove vegetation at 2.0 m above C.D. Two species were found coexisting in
two seagrass beds. Photo records were shown in Figure 3.7 of Appendix I while the complete records
of seagrass beds survey were shown in Annex III of Appendix I.
6.5.21 Table 3.2 of Appendix I summarize the results of seagrass beds survey in ST. Four
patches of Halophila ovalis were found while the total seagrass bed area was about 91.4 m2
(average area 22.8 m2). The largest patch was a long strand with
seagrass bed area 32.0 m2 and variable vegetation coverage 10-80%.
Two other patches were smaller strands (17.4 and 26.3 m2) with
variable vegetation coverage 30-60%. Both had co-existing seagrass Zostera japonica. The smallest patch was
about 15.8 m2 with highest percentage coverage 80%. For Zostera japonica, there were two long strands (17.4-26.3 m2) of seagrass beds with
low coverage percentage 10-20%. Both long strands had co-existing seagrass Halophila ovalis. The total seagrass bed area was about 43.7 m2 (average area 21.8 m2).
Temporal variation of seagrass beds
6.5.22 Figure 3.8 of Appendix I shows the changes of estimated total area of seagrass beds in ST along the sampling months. For Zostera japonica, it was not recorded in the 1st and 2nd surveys
of monitoring programme. Seasonal recruitment of few,
small patches (total seagrass area: 10 m2) was found in March 2013
that grew within the large patch of seagrass Halophila ovalis. Then the patch size increased and merged gradually with the warmer
climate from March to June 2013 (15 m2). However the patch size
decreased sharply and remained similar from September 2013 (4 m2) to
March 2014 (3 m2). In June 2014, the patch size increased obviously
again (41 m2) with warmer climate. Similar to previous year, the
patch size decreased again and remained similar September 2014 (2 m2)
to December 2014 (5 m2). From March to June 2015, the patch size
increased sharply again (90.0 m2). It might be due to the disappearance
of the originally dominant seagrass Halophila ovalis resulting in less competition
for substratum and nutrients. In September 2015, the patch size decreased and
was found coexisting with seagrass
Halophila ovalis. In
general, the seagrass bed of Zostera japonica fluctuated in patch size along the sampling months.
6.5.23
For Halophila ovalis, it was recorded as 3-4 medium
to large patches (area 18.9 - 251.7 m2; vegetation coverage 50-80%)
beside the mangrove vegetation at tidal level 2 m above C.D in the September
2012 (First survey). The
total seagrass bed area grew steadily from 332.3 m2 in September
2012 to 727.4 m2 in December 2013. Flowers could be observed in the
largest patch during its flowering period in December 2013. In March 2014, 31 small to medium
patches were newly recorded (variable area 1-72 m2 per patch,
vegetation coverage 40-80% per patch) in lower tidal zone between 1.0 and 1.5 m
above C.D. The total seagrass area increased further to 1350 m2. In
June 2014, these small and medium patches grew and extended to each others. These patches were no longer distinguishable
and were covering a significant mudflat area of ST. It was generally grouped
into 4 large areas (1116 ¡V 2443 m2) of seagrass beds characterized
of patchy distribution, variable vegetable coverage (40-80%) and smaller
leaves. The total seagrass bed area increased sharply to 7629 m2. In
September 2014, the total seagrass area declined sharply to 1111 m2.
There were only 3-4 small to large patches (6 - 253 m2) at high tidal
level and 1 patch at low tidal level (786 m2). Typhoon or strong water current was a possible cause (Fong, 1998). In September
2014, there were two tropical cyclone records in Hong Kong (7th-8th
September: no cyclone name, maximum signal number 1; 14th-17th
September: Kalmaegi maximum signal number 8SE) before
the seagrass survey dated 21st September 2014. The strong water
current caused by the cyclone, Kalmaegi especially,
might have given damage to the seagrass beds. In addition, natural heat stress
and grazing force were other possible causes reducing seagrass beds area.
Besides, Halophila ovalis
could be found in other mud flat area surrounding the single patch. But it was
hardly distinguished into patches due to very low coverage (10-20%) and small
leaves.
6.5.24 In December 2014, all the seagrass patches of Halophila ovalis disappeared in ST. Figure 3.9 of Appendix I shows the difference of the original seagrass beds area nearby the
mangrove vegetation at high tidal level between June 2014 and December 2014.
Such rapid loss would not be seasonal phenomenon because the seagrass beds at
higher tidal level (2.0 m above C.D.) were present and normal in December 2012
and 2013. According to Fong (1998), similar incident had occurred in ST in the
past. The original seagrass area had declined significantly during the
commencement of the construction and reclamation works for the international
airport at Chek Lap Kok in
1992. The seagrass almost disappeared in 1995 and recovered gradually after the
completion of reclamation works. Moreover, incident of rapid loss of seagrass
area was also recorded in another intertidal mudflat in Lai Chi Wo in 1998 with
unknown reason. Hence Halophila ovalis was regarded as a short-lived
and r-strategy seagrass that can
colonize areas in short period but disappears quickly under unfavourable
conditions (Fong, 1998).
Unfavourable conditions to seagrass Halophila ovalis
6.5.25 Typhoon or strong water current was
suggested as one unfavourable condition to Halophila ovalis (Fong, 1998). As mentioned above, there were two tropical cyclone
records in Hong Kong in September 2014. The strong water current caused by the
cyclones might have given damage to the seagrass beds.
6.5.26 Prolonged light deprivation due to turbid water would be another unfavouable condition. Previous studies reported that Halophila ovalis had little tolerance to light deprivation. During experimental darkness,
seagrass biomass declined rapidly after 3-6 days and seagrass died completely
after 30 days. The rapid death might be due to shortage of available
carbohydrate under limited photosynthesis or accumulation of phytotoxic end
products of anaerobic respiration (details see Longstaff
et al., 1999). Hence the seagrass bed
of this species was susceptible to temporary light deprivation events such as
flooding river runoff (Longstaff and Dennison, 1999).
6.5.27 In order to investigate any
deterioration of water quality (e.g. more turbid) in ST, the water quality
measurement results at two closest monitoring stations SR3 and IS5 of the
EM&A programme were obtained from the water
quality monitoring team. Based on the results from June to December 2014, the
overall water quality was in normal fluctuation except there was one exceedance
of suspended solids (SS) at both stations in September. On 10th
September, 2014, the SS concentrations measured at mid-ebb tide at stations SR3
(27.5 mg/L) and IS5 (34.5 mg/L) exceeded the Action Level (≤23.5 mg/L and 120%
of upstream control station¡¦s reading) and Limit Level (≤34.4 mg/L and 130% of
upstream control station¡¦s reading) respectively. The turbidity readings at SR3
and IS5 reached 24.8-25.3 NTU and 22.3-22.5 NTU respectively. The temporary
turbid water should not be caused by the runoff from upstream rivers. Because
there was no rain or slight rain from 1st to 10th
September 2014 (daily total rainfall at the Hong Kong International Airport:
0-2.1 mm; extracted from the climatological data of Hong Kong Observatory). The
effect of upstream runoff on water quality should be neglectable
in that period. Moreover the exceedance of water quality was considered
unlikely to be related to the contract works of HKLR according to the
¡¥Notifications of Environmental Quality Limits Exceedances¡¦ provided by the
respective environmental team. The respective construction of seawall and stone
column works, which possibly caused turbid water, were carried out within silt
curtain as recommended in the EIA report. Moreover there was no leakage of
turbid water, abnormity or malpractice recorded during water sampling. In
general, the exceedance of suspended solids concentration was considered to be
attributed to other external factors, rather than the contract works.
6.5.28
Based on the weather condition and water quality results in ST, the
co-occurrence of cyclone hit and turbid waters in September 2014 might have
combined the adverse effects on Halophila ovalis that leaded to disappearance of this short-lived and r-strategy seagrass species. Fortunately
Halophila ovalis was a fast-growing species (Vermaat et al.,
1995). Previous studies showed that the seagrass bed could be recovered to the
original sizes in 2 months through vegetative propagation after experimental
clearance (Supanwanid, 1996). Moreover it was
reported to recover rapidly in less than 20 days after dugong herbivory (Nakaoka and Aioi, 1999). As
mentioned, the disappeared seagrass in ST in 1995 could recover gradually after
the completion of reclamation works for international airport (Fong, 1998). The
seagrass beds of Halophila ovalis might recolonize the mudflat of ST through seed reproduction as long
as there was no unfavourable condition in the coming
months.
6.5.29
From March to June 2015, 2-3 small
patches of Halophila ovalis were
newly found coinhabiting with another seagrass
species Zostera japonica. But its
total patch area was still very low relative to the previous records. The
recolonization rate was low while cold weather and insufficient sunlight were
possible factors between December 2014 and March 2015. Moreover, it would need
to compete with more abundant seagrass Zostera
japonica for substratum and nutrient. Since Zostera japonica had
extended and had covered the original seagrass bed of Halophila ovalis at certain degree. In September 2015, the total seagrass area of Halophila ovalis had increased rapidly from 6.8 m2
to 91.35 m2. It had recolonized its original patch locations and
covered Zostera japonica. Hence it was expected that the
seagrass bed of Halophila ovalis would
increase continually in the following months.
Impact of the HKLR project
6.5.30
The present survey was the 12th survey of the EM&A programme during the construction period. According to the
results of present survey, there was recolonization of both
seagrass species Halophila ovalis and Zostera japonica in ST. The seagrass patches
were believed in recovery. Hence the negative
impact of HKLR project on the seagrass was not significant. In case, adverse phenomenon (e.g. reduction of seagrass patch size, abnormal change of leave colour) is observed again, it would
be reported as soon as possible.
Intertidal Soft Shore Communities
6.5.31 Table 3.3 and Figure 3.10 of Appendix I show the types of
substratum along the horizontal transect at every tidal level in every sampling zone. The relative distribution of different substrata was
estimated by categorizing the substratum types (Gravels & Boulders / Sands /
Soft mud) of the ten random quadrats
along the horizontal transect. The distribution of
substratum types varied among tidal levels and sampling
zones:
¡P In TC1, high percentage of
¡¥Sands¡¦ (70%) was recorded at high tidal level which was different from
previous records (high percentage of ¡¥Gravels and Boulders¡¦). By direct
observation on site, there was no obvious change of substratum at high tidal
level. Hence it was simply due to more random quadrats laid on sandy substratum
in this sampling. High percentage of ¡¥Gravels and Boulders¡¦ was recorded
(80-100%) at mid and low tidal levels.
¡P In TC2, the substratum
distribution was different between tidal levels. At high tidal level, higher
percentage of ¡¥Sands¡¦ (60%) was recorded followed by ¡¥Soft mud¡¦ (30%). At mid
tidal level, higher percentage of ¡¥Sands¡¦ (70%) was recorded followed by
¡¥Gravels and Boulders¡¦ (30%). At low tidal level, higher percentage of ¡¥Soft
mud¡¦ (60%) was recorded followed by ¡¥Sands¡¦ (40%).
¡P In TC3, the substratum type was
clearly different between high-mid tidal level and low tidal level. ¡¥Sands¡¦ was
the main substratum type (90-100%) at high and mid tidal levels while ¡¥Gravels
and Boulders¡¦ was the main substratum type (100%) at low tidal level.
¡P In ST, the substratum type was
clearly different between high-mid tidal level and low tidal level. ¡¥Gravels
and Boulders¡¦ (90-100%) was the main substratum at high and mid tidal levels.
At low tidal level, higher percentage of ¡¥Sands¡¦ (70%) was recorded followed by
¡¥Gravels and Boulders¡¦ (30%).
6.5.32 There was neither consistent vertical nor horizontal zonation
pattern of substratum type in all sampling zones. Such heterogeneous variation should be caused by
different hydrology (e.g. wave in different direction and intensity) received
by the four sampling zones.
6.5.33 Table 3.4 of Appendix I lists the total abundance, density
and number of taxon of every phylum in this
survey. A total of 12502 individuals were recorded. Mollusca was significantly the most
abundant phylum (total individuals 11994, density 400 ind.
m-2, relative abundance 95.9%). The second
abundant phylum was Arthropoda (383 ind., 13 ind. m-2, 3.1%). The third and fourth abundant phyla were Annelida
(71 ind., 2 ind. m-2,
0.6%) and Sipuncula (23 ind., 1 ind. m-2, 0.2%). Relatively other phyla were very low in abundances (density £1 ind. m-2, relative abundance £0.1%). Moreover, the most diverse phylum was Mollusca (35 taxa)
followed by Arthropoda (13
taxa) and Annelida (9 taxa). There was 1 taxon recorded only for other phyla. The complete list of collected specimens is shown in Annex V of Appendix I.
6.5.34 Table 3.5 of
Appendix I show the number of individual, relative abundance and density of each
phylum in every sampling zone. The total abundance (2454-4506 ind.) varied among the four sampling zones while the phyla distributions were
similar. In general, Mollusca was the
most dominant phylum (no. of individuals: 2359-4297 ind.; relative abundance 94.9-98.0%; density 315-573 ind. m-2). Other phyla were significantly lower in number of individuals. Arthropoda was the
second abundant phylum (35-169 ind.; 1.4-3.8%; 5-23 ind.
m-2). Annelida was the third abundant phylum (32-35 ind.;
0.8-1.1%; 4-5 ind. m-2) in TC2 and TC3.
Sipuncula was the third or fourth abundant phylum (8-9 ind.;
0.3%; 1 ind. m-2) in TC1 and TC2. Cnidaria (sea anemone) was the third abundant phylum (12 ind.; 0.5%; 2 ind.
m-2) in ST. Relatively other phyla were low in abundance among the
four sampling zones (≤ 0.3%).
Dominant species in every sampling zone
6.5.35
Table 3.6 of
Appendix I lists the abundant species (relative abundance >10%) in every sampling zone. In TC1,
gastropod Batillaria multiformis was the
most abundant species (54
ind. m-2, relative abundance 29%)
followed by gastropods Cerithidea djadjariensis
(47 ind. m-2,
25%) and Cerithidea cingulata (38 ind.
m-2, 20%) at high tidal level (major substratum: ¡¥Sands¡¦).
However all abundant species were at low density relative to other sampling
zones. At mid tidal level (major substratum: ¡¥Gravels and Boulders¡¦), the
abundant species were gastropods Monodonta labio (112 ind. m-2, 34%), Batillaria multiformis
(79 ind. m-2, 24%) and rock oyster Saccostrea
cucullata (72 ind. m-2,
22%, attached on boulders) at low-moderate
densities. At low
tidal level (major substratum: ¡¥Gravels and Boulders¡¦), gastropod
Monodonta labio (242 ind. m-2, 47%) and rock oyster Saccostrea cucullata (121 ind. m-2,
24%) were abundant at moderate-high densities.
6.5.36
At TC2, gastropod Cerithidea djadjariensis
(407 ind. m-2,
53%) was the most abundant at high density followed by Cerithidea cingulata (157 ind. m-2,
20%) at high tidal level
(major substratum: ¡¥Sands¡¦). Relative to high tidal level, the density of every
taxon was much lower and similar at mid and low tidal levels. No dominant
species was determined. At mid tidal level (major substratum: ¡¥Sands¡¦), rock oyster Saccostrea cucullata
(76 ind. m-2, 25%, attached on boulders), gastropods
Batillaria zonalis (73 ind. m-2, 24%), Monodonta labio (44 ind. m-2,
15%) and Cerithidea djadjariensis (31 ind. m-2,
10%) were commonly occurring at low density. At low
tidal level (major substratum: ¡¥Soft mud¡¦), Batillaria zonalis (41 ind. m-2, 34%), rock oyster Saccostrea cucullata
(24 ind. m-2, 20%) and
barnacle Balanus amphitrite (19 ind. m-2, 16%,
attached on boulders) were commonly
occurring at low density.
6.5.37 At TC3, the abundant species were
similar with variable densities at high and mid tidal levels (major substratum: ¡¥Sands¡¦). There
were gastropods Cerithidea djadjariensis (146-257 ind. m-2,
25-35%), Batillaria multiformis
(143-256 ind. m-2, 25-35%) and Cerithidea cingulata (128-222 ind. m-2,
18-39%) at moderate
densities. At low
tidal level (major substratum: ¡¥Gravels and Boulders¡¦), gastropod
Monodonta labio (197 ind. m-2, 39%) and rock oyster Saccostrea cucullata (146 ind. m-2,
29%, attached on boulders) were abundant at moderate densities.
Little black mussel Xenostrobus atratus (48 ind. m-2, 10%) was
the third abundant species at low density.
6.5.38 At ST, gastropod Monodonta labio (130-145 ind. m-2, 34-38%) and rock oyster Saccostrea cucullata (80-91 ind. m-2,
21-24%, attached on boulders) were the abundant
species of low-moderate densities at high and mid tidal levels (major
substratum: ¡¥Gravels and Boulders¡¦). Gastropods Batillaria multiformis (76 ind.
m-2, 20%) and Lunella coronata (45 ind.
m-2, 12%) were the third abundant species at high tidal
level and mid tidal level respectively. At low
tidal level (major substratum: ¡¥Sands¡¦), rock oyster Saccostrea cucullata (71 ind.
m-2, 33%) was the most abundant followed by
gastropods Lunella coronata
(41 ind. m-2, 19%) and Euchelus
scaber (30 ind. m-2, 14%). All
three species were at low densities.
6.5.39 In general, there was no consistent zonation
pattern of species distribution observed across all sampling zones and tidal levelsThe species
distribution should be determined by the type of substratum primarily. In general, gastropods Cerithidea djadjariensis
(total number of individuals: 2350 ind., relative
abundance 18.8%), Batillaria multiformis (1757
ind., 14.1%), and Cerithidea cingulata (1561
ind., 12.5%) and Batillaria zonalis (468 ind., 3.7%) were the most commonly occurring species on
sandy and soft mud substrata. Gastropods Monodonta
labio (2249 ind.,
18.0%), Lunella coronata
(408 ind., 3.3%) and rock oyster Saccostrea cucullata
(1930 ind., 15.4%) were commonly occurring species inhabiting
gravel and boulders substratum.
6.5.40 Relative
to the results of previous sampling (June 2015), the densities of gastropod Batillaria multiformis declined sharply in TC1, TC3 and ST. Heat
stress was one possible cause of population decline. According to the online
database of Hong Kong Observatory, there were 14, 13 and 18 days with ¡¥Very
Hot Weather Warning¡¦ in June, July and August 2015 respectively (total 45 days) with mean
monthly ambient temperature 29.1-29.7 ˚C. Moreover majority of low tide period
occurs in day time of summer (especially afternoon) in Hong Kong. The
substratum between mid and high tidal levels would be strongly heated under
direct sunshine with little water splashing. Since this gastropod species
usually inhabits at high and mid tidal levels, high mortality rate would be
resulted. Its population was believed to be restored gradually during dry season.
Biodiversity and abundance of soft
shore communities
6.5.41 Table 3.7 of
Appendix I shows
the mean values of number of species, density, biodiversity index H¡¦ and species evenness J of soft shore communities at every tidal level and in every sampling zone. Among the sampling zones, the
mean species number (10 spp. 0.25 m-2) and mean H¡¦ (1.6) in ST were slightly higher than other sampling zones (mean
species number: 8 spp. 0.25 m-2, H¡¦
1.3-1.4). The mean densities were quite variable among sites. The mean density
of TC3 (601 ind. m-2) was higher than
other sampling zones (327-398 ind. m-2).
However mean J showed no clear
difference among sampling zones (0.6-0.7).
6.5.42 Across the tidal levels, there
was no consistent difference of the mean number of species, H¡¦ and J in all sampling zones. For the mean density, a general decreasing
trend was observed from high tidal level to low tidal level at TC2, TC3 and ST.
At TC1, the mean density at low tidal level was higher than that at high and
mid tidal levels. As mentioned, the variation of mean density should be
determined by the type of substratum primarily.
6.5.43 Figures 3.11 to 3.14 of Appendix I show the temporal changes of mean number of species, mean density,
H¡¦ and J at every tidal level and in every sampling
zone along the sampling months. From Jun. to Sep. 2015, the mean densities
decreased clearly at high tidal level in TC1 and ST. As mentioned, it was due
to higher mortality of dominant gastropod Batillaria multiformis under heat stress of wet season.
Overall no consistent temporal change of any biological parameters was
observed. All the parameters were under slight and natural fluctuation with the
seasonal variation.
Impact of the HKLR project
6.5.44 The present survey was the 12th
survey of the EM&A programme during the construction period. Based on the results, impacts
of the HKLR project were not detected on intertidal soft shore community. In case,
abnormal phenomenon (e.g. large reduction of fauna densities and species
number) is observed, it would be reported as soon as possible.
6.6.1 Chan, K.K., Caley, K.J., 2003.
Sandy Shores, Hong Kong Field Guides 4. The Department of Ecology & Biodiversity,
The University of Hong Kong. pp 117.
6.6.2 Dai, A.Y., Yang, S.L., 1991.
Crabs of the China Seas. China Ocean Press. Beijing.
6.6.3 Dong, Y.M., 1991. Fauna of ZheJiang Crustacea. Zhejiang Science and Technology
Publishing House. ZheJiang.
6.6.4 EPD, 1997. Technical Memorandum
on Environmental Impact Assessment Process (1st edition).
Environmental Protection Department, HKSAR Government.
6.6.5 Fauchald, K., 1977. The polychaete worms. Definitions and keys to the orders,
families and genera. Natural History Museum of Los Angeles County, Science
Series 28. Los Angeles, U.S.A.
6.6.6 Fong, C.W., 1998. Distribution of
Hong Kong seagrasses. In: Porcupine!
No. 18. The School of Biological Sciences, The University of Hong Kong, in
collaboration with Kadoorie Farm & Botanic Garden
Fauna Conservation Department, p10-12.
6.6.7 Li, H.Y., 2008. The Conservation
of Horseshoe Crabs in Hong Kong. MPhil Thesis, City University of Hong Kong, pp
277.
6.6.8 Longstaff, B.J., Dennison, W.C., 1999.
Seagrass survival during pulsed turbidity events: the effects of light
deprivation on the seagrasses Halodule pinifolia and Halophila ovalis. Aquatic Botany 65 (1-4), 105-121.
6.6.9 Longstaff, B.J., Loneragan,
N.R., O¡¦Donohue, M.J., Dennison, W.C., 1999. Effects
of light deprivation on the survival and recovery of the seagrass Halophila ovalis (R.
Br.) Hook. Journal of Experimental Marine Biology and Ecology 234 (1), 1-27.
6.6.10 Nakaoka, M., Aioi,
K., 1999. Growth of seagrass Halophila ovalis at dugong trails compared to existing
within-patch variation in a Thailand intertidal flat. Marine Ecology Progress
Series 184, 97-103.
6.6.11 Pielou, E.C., 1966. Shannon¡¦s formula
as a measure of species diversity: its use and misuse. American Naturalist 100,
463-465.
6.6.12 Qi, Z.Y., 2004. Seashells of
China. China Ocean Press. Beijing, China.
6.6.13 Qin, H., Chiu, H., Morton, B.,
1998. Nursery beaches for Horseshoe Crabs in Hong Kong. In: Porcupine! No. 18. The School of
Biological Sciences, The University of Hong Kong, in collaboration with Kadoorie Farm & Botanic Garden Fauna Conservation
Department, p 9-10.
6.6.14 Shannon, C.E., Weaver, W., 1963.
The Mathematical Theory of Communication. Urbana:
University of Illinois
Press, USA.
6.6.15 Shin, P.K.S., Li, H.Y., Cheung,
S.G., 2009. Horseshoe Crabs in Hong Kong: Current Population Status and Human
Exploitation. Biology and Conservation of Horseshoe Crabs (part 2), 347-360.
6.6.16 Supanwanid, C., 1996. Recovery of the
seagrass Halophila ovalis after
grazing by dugong. In: Kuo, J., Philips, R.C.,
Walker, D.I., Kirkman, H. (eds), Seagrass biology: Proc Int
workshop, Rottenest Island, Western Australia. Faculty of Science, The University of Western Australia, Nedlands,
315-318.
6.6.17 Vermaat, J.E., Agawin,
N.S.R., Duarte, C.M., Fortes, M.D., Marba. N., Uri,
J.S., 1995. Meadow maintenance, growth and productivity of a mixed Philippine seagrass
bed. Marine Ecology Progress Series 124, 215-225.
6.6.18 Yang, D.J, Sun, R.P., 1988. Polychaetous annelids commonly seen from the Chinese waters
(Chinese version). China Agriculture Press, China.
7
Environmental Site
Inspection and Audit
7.1.1 Site
Inspections were carried out on a weekly basis to monitor the implementation of
proper environmental pollution control and mitigation measures for the Project.
During the reporting month, five site inspections were carried out on 2, 9, 16, 25 and 30 September 2015.
7.1.2 Particular
observations during the site inspections and the follow up actions
taken by the Contractor are described below.
2 September 2015
(a)
The alignment of silt
curtains did not follow the design plan at Portion X. The silt curtains was
realigned to follow the design plan. This observation was found on 22 July 2015 and
closed on 2 September 2015.
(b)
A gap was observed
between sections of silt curtains at Portion X. The gap was filled up by
additional silt curtains. This observation was found on 22 July 2015 and closed
on 2 September 2015.
(c)
Dry dusty material was found on the ground after
the loading/unloading activity at S7. The dry dusty material was cleaned up by the
Contractor. This observation was found on 5 August 2015 and closed on 2
September 2015.
(d)
A stockpile of dry crushed stones was found at
S7. Water spraying was
provided for the stockpile of dry crushed stone. This observation was found on 5 August 2015 and
closed on 2 September 2015.
(e) No drip tray was provided for chemical containers
at S15. A drip tray was provided for the chemical containers. This observation
was found on 12 August 2015 and closed on 2 September 2015.
(f) The silt curtain which should be placed around the
aeronautical light was broken at Portion X. The broken silt curtain around the
aeronautical light at Portion X was replaced. This observation was found on 19
August 2015 and closed on 2 September 2015.
(g) The rubbish bin at access road of WA6 was full. The
rubbish was removed. This observation was found on 28 August 2015 and closed on
2 September 2015.
(h) A drip
tray was not provided to the chemical containers inside West Tunnel. The chemical containers were removed. This
observation was found on 28 August 2015 and closed on 2 September 2015.
(i) A drip
tray was not provided for the chemical containers under the bridge at West
Tunnel site. The chemical
containers were removed. This observation was found on 28 August 2015 and
closed on 2 September 2015.
(j) The container for collecting general wastes was
full and rubbish was placed next to the container at S15. The rubbish was
removed by the Contractor. This observation was found on 2 September 2015 and
closed on 9 September 2015.
(k) The alignment of the silt curtain did not follow
the design plan at Portion X. This observation has been outstanding since 2
September 2015. The Contractor was reminded to follow the design plan of silt
curtain at Portion X.
(l) Muddy water was leaked from the wheel washing bay
to the sea at S7. The muddy water discharge was stopped by diverting the
wastewater to a sump pit. This observation was found on 2 September 2015 and
closed on 9 September 2015.
(m) Stagnant water was accumulated inside an I-beam at
N4. The stagnant water was cleaned up by the Contractor. This observation was found on 2 September 2015 and
closed on 9 September 2015.
(n) Stagnant water was observed inside a drip tray at
N4. The stagnant water inside the drip tray was cleaned up. This observation
was found on 2 September 2015 and closed on 9 September 2015.
(o) Many emptied cement bags were placed on the ground
at S11. The emptied
cement bags were removed. This observation was found on 2 September 2015 and closed on 9 September
2015.
(p) Stagnant water was found inside an abandon wheel
washing bay at N20. The
stagnant water was cleaned up inside the abandon wheel washing bay. This
observation was found on 2 September 2015 and closed on 16 September 2015.
9 September 2015
(a) The alignment of the silt curtain did not follow
the design plan at Portion X. This observation has been outstanding since 2
September 2015. The Contractor was reminded to follow the design plan of silt
curtain at Portion X.
(b)
Rubbish was
accumulated on the ground at N1. The rubbish was removed by contractor. This
observation was found on 9 September 2015 and closed on 16 September 2015.
(c)
There were not enough
sand bags to be placed along the boundary of dusty materials at N1. Additional
sand bags were placed along the boundary of the dusty materials. This
observation was found on 9 September 2015 and closed on 16 September 2015.
(d)
Sand bags placed
along the road were broken at N20. The broken sand bags were removed and new
sand bags were placed along the road. This observation was found on 9 September
2015 and closed on 16 September 2015.
(e)
A container for
general refuse was full and rubbish was placed next to the container at S15. The rubbish was removed by the Contractor. This
observation was found on 9 September 2015 and closed on 16 September 2015.
(f)
A wastewater
treatment plant was not used at S25. The wastewater was contained within the
construction site. After the site
inspection, the Contractor pump the wastewater to wastewater treatment plant
for treatment prior to discharge. This observation was found on 9 September
2015 and closed on 16 September 2015.
(g) Surface runoff was not directed to a wastewater
treatment system at N1. The surface runoff was pumped to a wastewater treatment
system for treatment after the site inspection. This observation was found on 9 September
2015 and closed on 16 September 2015.
(h)
Stagnant water was
observed inside an abandon wheel washing bay at N20. The stagnant water inside
the abandon wheel washing bay was cleaned up. This observation was found on 9
September 2015 and closed on 16 September 2015.
16 September 2015
(a) The alignment of the silt curtain did not follow
the design plan at Portion X. This observation has been outstanding since 2
September 2015. The Contractor was reminded to follow the design plan of silt
curtain at Portion X.
(b)
No sand bags were
placed around the storage area for aggregate / clay at vessel Shun Tat 82. Sand
bags were placed the around the storage area for aggregate / clay. This observation was found on 16 September 2015 and
closed on 25 September 2015.
(c) Rubbish was found near seaside at S7. The rubbish
was removed. This observation was found on 16 September 2015 and closed on 25
September 2015.
(d) Muddy surface runoff was observed at S7. The muddy water runoff
was stopped by the Contractor. This observation was found on 16 September 2015
and closed on 25 September 2015.
(e) A drilling machine was partly covered and fugitive
dust was observed at S15. A proper cover was provided to the drilling machines
at S15. This observation was found on 16 September 2015 and closed on 25
September 2015.
(f) No labour was provided for a wheel washing facility
at WA4 to wash wheels of vehicles leaving the site. A labour was provided to
wash wheels of vehicles at WA4. This observation was found on 16 September 2015
and closed on 25 September 2015.
(g) A rubbish bin at WA6 was full. The rubbish was
removed. This observation was found on 16 September 2015 and closed on 25
September 2015.
(h) Holes of water barriers were not sealed at WA6.
Holes of the water barriers at WA6 were sealed. This observation was found on
16 September 2015 and closed on 25 September 2015.
25 September 2015
(a) The alignment of the silt curtain did not follow
the design plan at Portion X. This observation has been outstanding since 2
September 2015. The Contractor was reminded to follow the design plan of silt
curtain at Portion X.
(b) Mechanical cover of dump truck was not covered near
at Portion Y. The mechanical cover of a dump truck was closed during
transportation of materials at Portion Y. This observation was found on 25
September 2015 and closed on 30 September 2015.
(c) Water dripping from air-conditioner was observed at
Portion Y. The Contractor used a red bucket to contain the water dripping. This
observation was found on 25 September 2015 and closed on 30 September 2015.
(d) Accumulated rubbish was observed at Portion Y. The
rubbish was removed. This observation was found on 25 September 2015 and closed
on 30 September 2015.
(e) No drip tray was observed for the oil drums at
Portion Y. Drip trays were provided for the oil drums. This observation was
found on 25 September 2015 and closed on 30 September 2015.
(f) Stagnant water was observed at Portion Y. The
stagnant water was cleared up. This observation was found on 25 September 2015
and closed on 30 September 2015.
(g)
Stagnant water was
observed at S16 site entrance. The stagnant water was cleared up. This observation was found on 25 September 2015 and
closed on 30 September 2015.
(h)
Rubbish was observed
inside the tunnel at N1. The rubbish was removed. This observation was found on 25 September 2015 and
closed on 30 September 2015.
30 September 2015
(a) The alignment of the silt curtain did not follow
the design plan at Portion X. This observation has been outstanding since 2
September 2015. The Contractor was reminded to follow the design plan of silt
curtain at Portion X.
(b)
Muddy water was
leaked out from holes of sand bucket into the sea from the storage area at Shun
Tat 82. The Contractor was reminded to block the holes
of the sand bucket and stop leaking of muddy water.
(c)
The alignment of silt
curtain for barging point did not follow the design plan at Portion X. The
Contractor was reminded to follow the design plan of silt curtain at Portion
X.
(d) No sand bags were placed along the road at N20. The
Contractor was reminded to place sand bags along the road at N20.
(e) Wheels of a dump truck were not washed before
leaving the site at N20. The Contractor was reminded to provide wheel washing
for the dump truck before leaving the site at N20
(f) Stagnant water pool was observed on surface at S8.
The Contractor was reminded to clean up the stagnant water at S8.
(g) No water spraying was provided for drilling
activity at S8. The Contractor was reminded to provide the water spraying for
drilling activity at S8.
(h) Unpaved road was dry and fugitive dust emission was
observed when there was vehicle movement at S16. The Contractor was reminded to
spray water regularly on the unpaved road at S16.
(i) No sand bags were placed along the site boundary at
S25 and there was a potential to wash away the sand into the sea. The
Contractor was reminded to provide sand bags along the site boundary at S25.
(j) A wastewater treatment was not used at S25. The
Contractor was reminded to use the wastewater treatment system at S25 if
necessary.
(k) General waste was accumulated on bare ground at
S25. The Contractor was reminded to collect the general waste and disposal of
regularly at S25.
The
Contractor has rectified most of the observations as
identified during environmental site inspections within the reporting month.
Follow-up actions for outstanding observations will be inspected during the
next site inspections.
7.2
Advice on the Solid and Liquid Waste Management Status
7.2.1 The
Contractor registered as a chemical waste producer for the Project. Sufficient
numbers of receptacles were available for general refuse collection and
sorting.
7.2.2
Monthly summary of waste flow table is detailed
in Appendix J.
7.2.3 The
Contractor was reminded that chemical waste containers should be properly
treated and stored temporarily in designated chemical waste storage area on
site in accordance with the Code of Practice on the Packaging, Labelling and
Storage of Chemical Wastes.
7.3.1 The valid
environmental licenses and permits during the reporting month are summarized in
Appendix L.
7.4.1 In
response to the site audit findings, the Contractors have rectified most of the observations as
identified during environmental site inspections during the reporting month.
Follow-up actions for outstanding observations will be inspected during the
next site inspections.
7.4.2 A summary
of the Implementation Schedule of Environmental Mitigation Measures (EMIS) is
presented in Appendix M. Most of
the necessary mitigation measures were implemented properly.
7.4.3
Regular marine travel route for
marine vessels were implemented properly in accordance to the submitted plan
and relevant records were kept properly.
7.4.4
Dolphin Watching Plan was
implemented during the reporting month. No dolphins inside the silt curtain
were observed. The relevant records were kept properly.
7.5.1
No Action and Limit Level
exceedances of 1-hour
TSP and 24-hr TSP level were recorded at AMS5 and AMS6 during the reporting
month.
7.5.2
For construction noise, no Action and Limit Level exceedances were
recorded at the monitoring stations during the reporting month.
7.5.3 For marine water quality monitoring, one Action Level
exceedances of suspended solid level were recorded during the reporting month.
No Limit Level exceedance of suspended solid level was recorded. No Action
Level/ Limit Level exceedances of turbidity
level and dissolved oxygen level were recorded during the reporting month.
7.6
Summary of Complaints, Notification of Summons and
Successful Prosecution
7.6.1 There were no complaints received during the reporting month. However, EPD informed SOR and IEC
that there was an enquiry regarding untreated wastewater discharge on 29
September 2015 via email. An
investigation is being undertaken and investigation report will be sent to EPD
for record. The details of cumulative
statistics of Environmental Complaints are provided in Appendix K.
7.6.2 No
notification of summons and prosecution was received during the reporting
period.
7.6.3 Statistics
on notifications of summons and successful prosecutions are summarized in Appendix N.
8.1.1 As
informed by the Contractor, the
major construction activities for October 2015 are summarized in Table 8.1.
Table 8.1 Construction
Activities for October 2015
Site Area
|
Description of
Activities
|
Portion X
|
Dismantling/Trimming
of Temporary 40mm Stone Platform for Construction of Seawall
|
Portion X
|
Filling
Works behind Stone Platform
|
Portion X
|
Construction of Seawall
|
Portion X
|
Loading and Unloading of
Filling Material
|
Portion X
|
Pipe Piling
|
Portion X
|
Band Drains Installation
|
Portion X
|
Excavation and Lateral Support Works at Scenic
Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Laying Blinding Layer for Tunnel Box Structure at
Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of Tunnel Box Structure at Scenic
Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Socket H-Piling work at Scenic Hill Tunnel (Cut
& Cover Tunnel)
|
Portion X
|
Construction of Sheet Pile at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Excavation Works for HKBCF to Airport Tunnel
|
Portion X
|
Sheet Piling Works for HKBCF to Airport Tunnel
East (Cut & Cover Tunnel)
|
Portion X
|
Socket H-Piling works for HKBCF to Airport Tunnel
East (Cut & Cover Tunnel)
|
Portion X
|
Pipe Piling works for HKBCF to Airport Tunnel
East (Cut &Cover Tunnel)
|
Airport Road
|
Works for Diversion of
Airport Road
|
Airport Road / Airport Express Line/East Coast
Road
|
Utilities Detection
|
Airport Road / Airport Express Line/East Coast
Road
|
Establishment of Site Access
|
Airport Road/Airport Express Line
|
Canopy Pipe Drilling/ Mined Tunnel Excavation/
Box Jacking underneath Airport Road and Airport Express Line
|
Kwo Lo Wan Road
|
Excavation and Lateral Support Works at shaft 3
extension north shaft & south shaft
|
Airport Road
|
Excavation and Lateral Support Works for HKBCF to
Airport Tunnel West (Cut & Cover Tunnel)
|
Portion Y
|
Utility Culvert Excavation
|
Portion Y
|
Highway Operation and Maintenance Area Building
Foundation & Sub-structure Works
|
West Portal
|
Excavation for Scenic Hill Tunnel
|
West Portal
|
Ventilation Building Foundation and
Superstructure Works
|
8.2
Environmental Monitoring Schedule for the
Coming Month
8.2.1
The tentative schedule for environmental monitoring in October 2015 is
provided in Appendix D.
9.1.1 The
construction phase and EM&A programme of the Contract commenced on 17
October 2012.
Air Quality
9.1.2
No Action and Limit Level
exceedances of 1-hour
TSP and 24-hr TSP level were recorded at AMS5 and AMS6 during the reporting
month.
Noise
9.1.3 For
construction noise, no Action and Limit Level exceedances were recorded at the
monitoring stations during the reporting month.
Water Quality
9.1.4 For marine water quality monitoring, one Action Level
exceedances of suspended solid level were recorded during the reporting month.
No Limit Level exceedance of suspended solid level was recorded. No Action
Level/ Limit Level exceedances of turbidity
level and dissolved oxygen level were recorded during the reporting month.
Dolphin
9.1.5
During the September¡¦s surveys of the Chinese
White Dolphin, no adverse impact from the activities of this construction project on Chinese White Dolphins was
noticeable from general observations.
9.1.6
Due to monthly variation in dolphin occurrence within the study area, it
would be more appropriate to draw conclusion on whether any impacts on dolphins
have been detected related to the construction activities of this project in
the quarterly EM&A report, where comparison on distribution, group size and
encounter rates of dolphins between the quarterly impact monitoring period (September 2015 ¡V November 2015) and baseline monitoring period (3-month period) will be made.
Mudflat
9.1.7 This measurement result was
generally and relatively higher than the baseline measurement at S1, S2, S3 and
S4. The mudflat level is continuously increased.
9.1.8 The September 2015 survey results
indicate that the impacts of the HKLR project could not
be detected on horseshoe crabs, seagrass and intertidal soft shore community.
Environmental Site
Inspection and Audit
9.1.9
Environmental site inspection
was carried out on 2, 9, 16, 25 and 30 September 2015. Recommendations on remedial actions were
given to the Contractors for the deficiencies identified during the site
inspections.
9.1.10
There were no complaints
received in relation to the environmental impact during the reporting period.
9.1.11
No
notification of summons and prosecution was received during the reporting
period.