Executive Summary
Prior to the commencement
of 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), Highways Department employed environmental
specialist under Agreement No. CE35/2011 (EP) and Contract No. HY/2011/02 to
carry out baseline environmental monitoring in air quality, noise water quality
and ecology (Chinese White Dolphin) to facilitate early commencement of
construction of Hong Kong Boundary Crossing Facilities (HKBCF) reclamation
works and the Tuen Mum – Chek Lap Kok Link (TM-CLKL) advance Southern Landfall
reclamation works under Contract No. HY/2010/02. The baseline environmental monitoring
for air quality, noise, water quality and ecology (Chinese White Dolphin) was
undertaken between September and November 2011 in accordance with requirements
provided in the Environmental Monitoring and Audit (EM&A) Documents for the
Hong Kong Link Road (HKLR), HKBCF and TM-CLKL. A Baseline Environmental Monitoring
Report (Version C) for Hong Kong-Zhuhai-Macao Bridge Hong Kong Projects –
Investigation (hereafter referred to as “BEMR”) was prepared to fulfil
environmental permit conditions for HKBCF (including TM-CLKL southern landfall)
project. The BEMR presented
monitoring locations, equipment, period, methodology, results and observations
and is available from the website of Agreement No. CE 48/2011 (EP)
Environmental Project Office (ENPO) for the Hong Kong-Zhuhai-Macao Bridge Hong
Kong Link Road, Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing
Facilities, & Tuen Mun-Chek Lap Kok Link – Investigation:
http://www.hzmbenpo.com/
There are a total of two air
quality monitoring stations, one noise monitoring station and thirteen water
quality monitoring stations for this Contract No. HY/2011/03. As these environmental monitoring
locations were also covered in the BEMR, the baseline monitoring results for
these environmental monitoring locations will be adopted for the Contract.
This Baseline Environmental
Monitoring Report has been prepared based on baseline mudflat monitoring
results and baseline monitoring results presented in the BEMR.
The Action and Limit Levels
for air quality, noise, water quality and ecology (Chinese White Dolphin) were
developed based on the baseline monitoring results presented in the BEMR.
According to the baseline
mudflat monitoring, surveys for horseshoe crabs, seagrass beds, intertidal soft
shore communities as well as sedimentation rate monitoring were conducted in
September 2012 at the specified mudflat survey areas.
The mudflat monitoring
covered water quality monitoring data.
Reference was made to the water quality baseline monitoring data of the
representative water quality monitoring station (i.e. SR3) as presented in the
BEMR. Baseline water quality
monitoring in San Tau (monitoring station, SR3) was conducted in October 2011
prior to the construction of the HZMB.
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. The
split of environmental monitoring and audit works for these two contracts have
been clarified in Environmental Project Office’s letter ref.:
HYDHZMBEEM00_0_0424L.12 which was sent to Environmental Protection Department
on 17 October 2012.
1.1.3 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.
1.1.5 The baseline
environmental monitoring was undertaken between September and November 2011 in
accordance with requirements in the Environmental Monitoring and Audit
(EM&A) Documents for the HKLR, HKBCF and TM-CLKL. A Baseline Environmental Monitoring Report
(Version C) dated 8 March 2012 for Hong Kong-Zhuhai-Macao Bridge Hong
Kong Projects – Investigation (hereafter referred to as BEMR) was prepared to present monitoring locations,
equipment, period, methodology, results and observations and is
available from the website of Agreement No. CE 48/2011 (EP) Environmental
Project Office (ENPO) for the Hong Kong-Zhuhai-Macao Bridge Hong Kong Link
Road, Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities,
& Tuen Mun-Chek Lap Kok Link – Investigation:
http://www.hzmbenpo.com/
1.1.6 The
relevant baseline monitoring results for air quality, noise, water quality and
ecology (Chinese White Dolphin) presented in the BEMR have been adopted for
this Contract as the baseline monitoring were undertaken prior to the
commencement of the Contract and other nearby construction contracts in
accordance with the EM&A requirements for the Contract.
1.1.7 This
Baseline Environmental Monitoring Report is prepared to document Action
and Limit Levels for air quality, noise, water quality, ecology (Chinese White
Dolphin) which are extracted from the BEMR and baseline mudflat monitoring
results for the Contract. The baseline levels
will be used as the basis for compliance check during the impact monitoring for
the Contract.
2.1.1
There are a total
of two air quality monitoring stations for the Contract and they
are the same baseline monitoring stations presented in the BEMR. The baseline air quality monitoring was
undertaken approximately one year prior to the commencement of the Contract and
other nearby construction contracts.
Therefore, the baseline monitoring results together with the Action and
Limit Levels for these monitoring stations are considered applicable for the
Contract. The air quality
monitoring stations for the Contract are listed in Table 2.1 and shown in Appendix A.
Table 2.1 Locations
of Air Quality Monitoring Stations
|
Monitoring
Stations
|
Location
|
|
AMS 5
|
Ma Wan Chung Village (Tung Chung)
|
|
AMS 6
|
Dragonair / CNAC (Group) Building (HKIA)
|
2.2
Monitoring Methodology and Results
2.2.1 The monitoring methodology and results are
detailed in the
BEMR. The baseline monitoring
results provided in Tables 3.4 and 3.5 of the BEMR will be adopted for the
Contact as the baseline monitoring stations for the Contract are the same as
those presented in the BEMR. A summary of the average 1-hour
TSP concentration and 24-hour TSP concentration is provided in Table 2.2 and Table 2.3, respectively.
Table 2.2 Summary
of Baseline 1-hour TSP Monitoring Results
|
Monitoring
Station
|
Average 1-hour
TSP Concentration, µg/m3
(Range)
|
|
AMS 5
|
156.9
(82.2 – 246.6)
|
|
AMS 6
|
169.2
(87.8 – 273.2)
|
Table 2.3 Summary
of Baseline 24-hour TSP Monitoring Results
|
Monitoring
Station
|
Average
24-hour TSP Concentration, µg/m3
(Range)
|
|
AMS 5
|
52.9
(25.3 – 74.2)
|
|
AMS 6
|
66.4
(35.2 – 103.5)
|
2.3.1 The
Action and Limit Levels for the Contract have been extracted from Tables 3.8
and 3.9 of the BEMR and summarised in Table 2.4 and Table 2.5.
Table
2.4 Action
and Limit Levels for 1-hour TSP
|
Monitoring
Station
|
Action Level,
µg/m3
|
Limit Level,
µg/m3
|
|
AMS 5
|
352
|
500
|
|
AMS 6
|
360
|
Table 2.5 Action
and Limit Levels for 24-hour TSP
|
Monitoring
Station
|
Action Level,
µg/m3
|
Limit Level,
µg/m3
|
|
AMS 5
|
164
|
260
|
|
AMS 6
|
173
|
2.4.1
Should non-compliance of the air quality criteria
occur, actions in accordance with the Action Plan in Table 2.6 shall be carried out.
Table 2.6 Event
and Action Plan for Air Quality
|
Event
|
Action
|
|
ET
|
IEC
|
SO
|
Contractor
|
|
Exceedance of Action Level for one
sample
|
1. Identify
source, investigate the causes of exceedance and propose remedial measures;
2. Inform
IEC and SO;
3. Repeat
measurement to confirm finding;
4. Increase
monitoring frequency to daily.
|
1. Check
monitoring data submitted by ET;
2. Check
Contractor’s working method.
|
1. Notify
Contractor.
|
1. Rectify
any unacceptable practice;
2. Amend
working methods if appropriate.
|
|
Exceedance of Action Level for two or
more consecutive samples
|
1. Identify
source;
2. Inform
IEC and SO;
3. Advise
the SO on the effectiveness of the proposed remedial measures;
4. Repeat
measurements to confirm findings;
5. Increase
monitoring frequency to daily;
6. Discuss with IEC
and Contractor on remedial actions required;
7. If
exceedance continues, arrange meeting with IEC and SO;
8. If
exceedance stops, cease additional monitoring.
|
1. Check
monitoring data submitted by ET;
2. Check
Contractor’s working method;
3. Discuss
with ET and Contractor on possible remedial measures;
4. Advise
the ET on the effectiveness of the proposed remedial measures;
5. Supervise
Implementation of remedial measures.
|
1. Confirm
receipt of notification of failure in writing;
2. Notify
Contractor;
3. Ensure
remedial measures properly implemented.
|
1. Submit
proposals for remedial to SO within 3 working days of notification;
2. Implement
the agreed proposals;
3. Amend
proposal if appropriate.
|
|
Exceedance of Limit Level for one
sample
|
1. Identify
source, investigate the causes of exceedance and propose remedial measures;
2. Inform
SO, Contractor and EPD;
3. Repeat
measurement to confirm finding;
4. Increase
monitoring frequency to daily;
5. Assess
effectiveness of Contractor’s remedial actions and keep IEC, EPD and SO
informed of the results.
|
1. Check
monitoring data submitted by ET;
2. Check
Contractor’s working method;
3. Discuss
with ET and Contractor on possible remedial measures;
4. Advise
the SO on the effectiveness of the proposed remedial measures;
5. Supervise
implementation of remedial measures.
|
1. Confirm
receipt of notification of failure in writing;
2. Notify
Contractor;
3. Ensure
remedial measures properly implemented.
|
1. Take
immediate action to avoid further exceedance;
2. Submit
proposals for remedial actions to IEC within 3 working days of notification;
3. Implement
the agreed proposals;
4. Amend
proposal if appropriate.
|
|
Exceedance of Limit Level for two or
more consecutive samples
|
1. Notify
IEC, SO, Contractor and EPD;
2. Identify
source;
3. Repeat
measurement to confirm findings;
4. Increase
monitoring frequency to daily;
5. Carry
out analysis of Contractor’s working procedures to determine possible
mitigation to be implemented;
6. Arrange
meeting with IEC and SO to discuss the remedial actions to be taken;
7. Assess
effectiveness of Contractor’s remedial actions and keep IEC, EPD and SO
informed of the results;
8. If
exceedance stops, cease additional monitoring.
|
1. Discuss
amongst SO, ET, and Contractor on the potential remedial actions;
2. Review
Contractor’s remedial actions whenever necessary to assure their
effectiveness and advise the SO accordingly;
3. Supervise
the implementation of remedial measures.
|
1. Confirm
receipt of notification of failure in writing;
2. Notify
Contractor;
3. In
consultation with the IEC, agree with the Contractor on the remedial measures
to be implemented;
4. Ensure
remedial measures properly implemented;
5. If
exceedance continues, consider what portion of the work is responsible and instruct
the Contractor to stop that portion of work until the exceedance is abated.
|
1. Take
immediate action to avoid further exceedance;
2. Submit
proposals for remedial actions to IEC within 3 working days of notification;
3. Implement
the agreed proposals;
4. Resubmit
proposals if problem still not under control;
5. Stop
the relevant portion of works as determined by the SO until the exceedance is
abated.
|
Note: ET – Environmental Team, IEC –
Independent Environmental Checker, SO – Supervising Officer
3.1.1
There is one noise monitoring stations for the
Contract and they are the same baseline monitoring stations presented in the
BEMR. The baseline noise monitoring
was undertaken approximately one year prior to the commencement of the Contract
and other nearby construction contracts.
Therefore, the baseline monitoring results together with the Action and
Limit Levels for these monitoring stations are considered applicable for the
Contract. The noise monitoring stations for the Contract are listed in Table 3.1 and shown in Appendix A.
Table 3.1 Locations
of Noise Monitoring Stations
|
Monitoring
Station
|
Location
|
|
NMS 5
|
Ma Wan Chung Village (Tung Chung)
|
3.2.1
The monitoring methodology and results are
detailed in the BEMR. The baseline monitoring results provided in Tables 4.5 – 4.7 of the BEMR
will be adopted for the Contact as the baseline monitoring stations for the
Contract is the same as those presented in the BEMR. The baseline
monitoring results are summarized in Table
3.2 to Table 3.4.
Table 3.2 Summary of Daytime (Normal Weekdays) Noise
Monitoring Results
|
Monitoring
Station
|
Daytime
0700-1900 hrs on normal weekdays
Range of Noise
Level, dB(A)
|
|
Leq (30 min)
|
L10 (5 min)
|
L90 (5 min)
|
|
Mean
|
Max
|
Min
|
Mean
|
Max
|
Min
|
Mean
|
Max
|
Min
|
|
NMS 5
|
55.3
|
63.5
|
51.0
|
57.5
|
74.1
|
50.8
|
51.1
|
61.7
|
48.3
|
Table 3.3 Summary
of Evening-Time & Daytime (Holiday) Noise Monitoring Results
|
Monitoring
Station
|
Evening-time
1900-2300 hrs on all days & Daytime 0700-1900 hrs on holidays
Range of Noise
Level, dB(A)
|
|
Leq (30
min)
|
L10 (5
min)
|
L90 (5
min)
|
|
Mean
|
Max
|
Min
|
Mean
|
Max
|
Min
|
Mean
|
Max
|
Min.
|
|
NMS 5
|
55.4
|
68.2
|
48.9
|
58.2
|
67.8
|
49.7
|
51.0
|
57.5
|
48.1
|
Table 3.4 Summary
of Night Time Noise Monitoring Results
|
Monitoring
Station
|
Night-time
2300-0700 hrs on the next day
Range of Noise
Level, dB (A)
|
|
Leq (30
min)
|
L10 (5
min)
|
L90 (5
min)
|
|
Mean
|
Max
|
Min
|
Mean
|
Max
|
Min
|
Mean
|
Max
|
Min
|
|
NMS 5
|
53.7
|
67.5
|
48.6
|
55.7
|
71.5
|
49.5
|
50.0
|
55.0
|
48.0
|
3.3.1
The Action and Limit Levels for the Contract
have been extracted from Table 4.9 of the BEMR and
summarised in Table 3.5.
Table 3.5 Action
Limit Levels for Noise during Construction Period
|
Monitoring
Station
|
Time Period
|
Action Level
|
Limit Level
|
|
NMS5
|
0700-1900 hrs on normal weekdays
|
When one documented complaint is received
|
75 dB(A)
|
Notes:
If works are to
be carried during restricted hours, the conditions stipulated in the
construction noise permit issued by the Noise Control Authority have to be
followed.
(*): Reduce to
65 dB (A) during school examination periods.
3.4.1 Should
non-compliance of the criteria occur, action in accordance with the Event and
Action Plan, as provided in Table 3.6,
shall be carried out.
Table 3.6 Event
and Action Plan for Construction Noise
|
Event
|
Action
|
|
ET
|
IEC
|
SO
|
Contractor
|
|
Exceedance of Action Level
|
1. Identify
source, investigate the causes of exceedance and propose remedial measures;
2. Notify
IEC and Contractor;
3. Report
the results of investigation to the IEC, SO and Contractor;
4. Discuss
with the Contractor and formulate remedial measures;
5. Increase
monitoring frequency to check mitigation effectiveness.
|
1. Review
the analysed results submitted by the ET;
2. Review
the proposed remedial measures by the Contractor and advise the SO accordingly;
3. Supervise
the implementation of remedial measures.
|
1. Confirm
receipt of notification of failure in writing;
2. Notify
Contractor;
3. Require
Contractor to propose remedial measures for the analysed noise problem;
4. Ensure
remedial measures are properly implemented
|
1. Submit
noise mitigation proposals to IEC;
2. Implement
noise mitigation proposals.
|
4.1.1
There are a total of thirteen water quality
monitoring stations specified under the ER for the contract. The baseline water quality monitoring was undertaken approximately one
year prior to the commencement of the Contract and other nearby construction
contracts. Therefore, the baseline
monitoring results together with the Action and Limit Levels for these
monitoring stations are considered applicable for the Contract. They are
listed in Table 4.1 and shown in Appendix A.
Table 4.1 Locations
of the 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
|
805849
|
818780
|
|
CS(Mf)5
|
Control Station
|
817990
|
821129
|
4.2.1
The monitoring methodology and results are
detailed in the BEMR. The baseline monitoring results provided in the BEMR will be adopted for
the Contact as the baseline monitoring stations for the Contract is the same as
those presented in the BEMR. Appendices C3 and C4 of the BEMR
detail the baseline monitoring results for the Contract.
4.3.1 The
Action and Limit Levels for the Contract have been extracted from Table 5.6 of
the BEMR and summarised in Table 4.2.
Table 4.2 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
|
47.0 or 130% of turbidity at the upstream control
station at the same tide of same day
|
|
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
|
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
|
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) All
the figures given in the table are used for reference only and the EPD may
amend the figures whenever it is considered as necessary.
(5) The
1 percentile of baseline data for dissolved oxygen (surface and middle) and
dissolved oxygen (bottom) are 4.2mg/L and 3.6mg/L respectively.
4.4.1 Should
non-compliance of the criteria occur, action in accordance with the Event and Action
Plan, as provided in Table 4.3,
shall be carried out.
Table 4.3 Event
and Action Plan for Water Quality
|
Event
|
Action
|
|
ET
Leader
|
IEC
|
SO
|
Contractor
|
|
Action level being exceeded by one
sampling day
|
1. Repeat
in situ measurement on next day of exceedance to confirm findings;
2. Identify
source(s) of impact;
3. Inform
IEC, contractor and SO;
4. Check
monitoring data, all plant, equipment and Contractor's working methods.
|
1. Check
monitoring data submitted by ET and Contractor’s working methods.
|
1. Confirm
receipt of notification of non-compliance in writing;
2. Notify
Contractor.
|
1. Inform
the SO and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Amend
working methods if appropriate.
|
|
Event
|
Action
|
|
ET
Leader
|
IEC
|
SO
|
Contractor
|
|
Action level being exceeded by two or
more consecutive sampling days
|
1. Repeat
measurement on next day of exceedance to confirm findings;
2. Identify
source(s) of impact;
3. Inform
IEC, contractor, SO and EPD;
4. Check
monitoring data, all plant, equipment and Contractor's working methods;
5. Discuss
mitigation measures with IEC, SO and Contractor;
6. Ensure
mitigation measures are implemented;
7. Increase
the monitoring frequency to daily until no exceedance of Action level;
|
1. Check
monitoring data submitted by ET and Contractor’s working method;
2. Discuss
with ET and Contractor on possible remedial actions;
3. Review
the proposed mitigation measures submitted by Contractor and advise the SO
accordingly;
4. Supervise
the implementation of mitigation measures.
|
1. Discuss
with IEC on the proposed mitigation measures;
2. Ensure
mitigation measures are properly implemented;
3. Assess
the effectiveness of the implemented mitigation measures.
|
1. Inform
the Engineer and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Check
all plant and equipment and consider changes of working methods;
4. Submit
proposal of additional mitigation measures to SO within 3 working days of
notification and discuss with ET, IEC and SO;
5. Implement
the agreed mitigation measures.
|
|
Limit level being exceeded by one
sampling day
|
1. Repeat
measurement on next day of exceedance to confirm findings;
2. Identify
source(s) of impact;
3. Inform
IEC, contractor, SO and EPD;
4. Check
monitoring data, all plant, equipment and Contractor's working methods;
5. Discuss
mitigation measures with IEC, SO and Contractor;
|
1. Check
monitoring data submitted by ET and Contractor’s working method;
2. Discuss
with ET and Contractor on possible remedial actions;
3. Review
the proposed mitigation measures submitted by Contractor and advise the SO
accordingly.
|
1. Confirm
receipt of notification of failure in writing;
2. Discuss
with IEC, ET and Contractor on the proposed mitigation measures;
3. Request
Contractor to review the working methods.
|
1. Inform
the SO and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Check
all plant and equipment and consider changes of working methods;
4. Submit
proposal of mitigation measures to SO within 3 working days of notification
and discuss with ET, IEC and SO.
|
|
Limit level being exceeded by two or
more consecutive sampling days
|
1. Repeat
measurement on next day of exceedance to confirm findings;
2. Identify
source(s) of impact;
3. Inform
IEC, contractor, SO and EPD;
4. Check
monitoring data, all plant, equipment and Contractor's working methods;
5. Discuss
mitigation measures with IEC, SO and Contractor;
6. Ensure
mitigation measures are implemented;
7. Increase
the monitoring frequency to daily until no exceedance of Limit level for two
consecutive days;
|
1. Check
monitoring data submitted by ET and Contractor’s working method;
2. Discuss
with ET and Contractor on possible remedial actions;
3. Review
the Contractor’s mitigation measures whenever necessary to assure their
effectiveness and advise the SO accordingly;
4. Supervise
the implementation of mitigation measures.
|
1. Discuss
with IEC, ET and Contractor on the proposed mitigation measures;
2. Request
Contractor to critically review the working methods;
3. Make
agreement on the mitigation measures to be implemented;
4. Ensure
mitigation measures are properly implemented;
5. Consider
and instruct, if necessary, the Contractor to slow down or to stop all or part
of the construction activities until no exceedance of Limit level.
|
1. Take
immediate action to avoid further exceedance;
2. Submit
proposal of mitigation measures to SO within 3 working days of notification
and discuss with ET, IEC and SO;
3. Implement
the agreed mitigation measures;
4. Resubmit
proposals of mitigation measures if problem still not under control;
5. As
directed by the Engineer, to slow down or to stop all or part of the
construction activities until no exceedance of Limit level.
|
5.1.1 The
monitoring methodology and results are detailed in Section 6 of the BEMR. In total, 112 groups of Chinese White
Dolphins, numbering 413 individuals, were observed during the three-month
baseline survey. Most were sighted
in the West Lantau and Northwest Lantau regions. The detailed monitoring results which
were extracted from Appendix D of BEMR are presented in Appendix C.
5.2
Event and Action Plan for Dolphin Monitoring
5.2.1 The Event
and Action Plan for dolphin monitoring for the Contract have been extracted
from Table 6.2 of the BEMR and summarised in Table 5.2.
Table 5.2 Event
and Action Plan for Dolphin Monitoring
|
Event
|
Action*
|
|
ET
|
IEC
|
SO
|
Contractor
|
|
Dolphin numbers and behaviour patterns recorded in
the construction and post-construction monitoring are significantly lower
than or different from those recorded in the pre-construction monitoring.
|
Repeat statistical data analysis to confirm
findings;
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 dolphin 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 confirm notification of the
non-compliance in writing;
Discuss with the ET and the IEC and propose
measures to the IEC and the SO;
Implement the agreed measures.
|
Notes:
ET – Environmental Team
IEC – Independent Environmental Checker
SO – Supervising Officer
* Action to be instigated within 1 month of an event
Sampling
Zone
6.1.1 There are
two survey areas specified under the ER for the Contract, namely Tung Chung Bay
and San Tau. Tung Chung Bay survey
area is divided into three sampling zones (TC1, TC2 and TC3) and there is one
sampling zone at San Tau (ST).
Survey of horseshoe crabs, seagrass beds and intertidal communities were
conducted in each sampling zone.
The locations of sampling zones are shown in Figure 6.1. The pre-construction
mudflat ecology monitoring was undertaken between 13 and 23 September 2012.
Horseshoe
Crabs
6.1.2 An active
search method was adopted for horseshoe crab survey at each sampling zone. The
survey was undertaken by 2 specialists each spending 2 to 3 hours at the site
subject to the site and tidal conditions for two days. Once a horseshoe crab was found, the
species, size and inhabiting substrate, photographic record and respective GPS
coordinate were recorded.
Seagrass
Beds
6.1.3 An active
search method was adopted for seagrass bed survey at each sampling zone. The survey was undertaken by 2
specialists each spending 2 to 3 hours at the site subject to the site and
tidal conditions for two days. Once
seagrass bed was observed, the species, the estimated area (m2),
photographic record and respective GPS coordinate were recorded.
Intertidal
Soft Shore Communities
6.1.4 The sandy
shore of San Tau and Tung Chung Bay from the uppermost part of the shore and to
the water edge was divided into three tidal zones – upper, middle and lower
zones, at each sampling zone, TC1, TC2, TC3 and ST. A 100m transect was laid in each of the
three tidal zones for fauna sampling.
6.1.5 At each
sampling zone, three 100m horizontal transects will be laid at 2.0m, 1.5m and
1.0m above C.D. Along each
transect, ten random quadrats (0.5 m x 0.5m) were placed. In each quadrat, the epifauna and infauna
(within the top 5cm sediment) in each quadrat were identified and their
numbers/coverage percentages were recorded. One core of 10cm diameter x 20cm depth
was also collected within each quadrat.
The sediments of the cores were sieved with 2mm mesh-size sieve and the
biota inside was identified and counted.
Species and abundance of biota in both cores and quadrats were reported.
6.2
Mudflat Ecology Monitoring Results
Horseshoe
Crabs
6.2.1 There
were 1, 9 and 16 individuals of Tachypleus
tridentatus observed at TC1, TC3 and ST respectively. In addition, grouping of T. tridentatus was also observed at TC3
and ST while each group consisted of 2 to 4 individuals of T. tridentatus. Survey
results are presented in Table 3.1 of Appendix
B. No individuals of T. tridentatus were observed at TC2.
6.2.2
The prosomal width was also measured for each
individual of T. tridentatus, and the
range of prosomal width was from 8.45mm to 59.32mm, which corresponds to an age
of 9 months to 8 years old. The
survey results have been grouped together for presentation. Summary of prosomal width of horseshoe
crab is shown in Table 6.1.
Table 6.1 Summary
of Prosomal Width of Horseshoe Crab Survey
|
|
TC1
|
TC2
|
TC3
|
ST
|
|
No. of
individuals
|
1
|
N/A
|
9
|
16
|
|
Mean prosomal width
(mm)
|
28.14
|
N/A
|
42.65
|
24.41
|
|
Range of
prosomal width (mm)
|
N/A
|
N/A
|
12.67 – 59.32
|
8.45 – 47.90
|
|
Search record
(individual hr-1 person-1)
|
0.25
|
N/A
|
1.50
|
2.67
|
Seagrass
Beds
6.2.3 Four
patches of Halophila ovalis were observed
at ST while no any patches of H. ovalis
were observed at the other sampling zones, TC1, TC2 and TC3. The survey results have been grouped
together for presentation. The
estimated total area and the mean area of H.
ovalis as observed at ST were 332.3m2 and 83.1m2,
respectively. Survey results for
seagrass beds are presented in Table 3.3 of Appendix B.
Intertidal
Soft Shore Communities
6.2.4 A total
of 15,188 individuals were recorded.
Mollusks were significantly abundant phylum (total individuals of
14,669; relative abundance of 96.6%, density of 489 individual m-2)
followed by the second abundant group, arthropod (total individuals of 467;
relative abundance of 3.1%, density of 16 individual m-2) at the
sampling zones. The summary of the
total abundance and total biomass of every phylum is presented in Table 3.5 of Appendix B. The complete list of
species recorded is shown in Appendix III of Appendix B.
6.2.5 In
general, molluscs were the most dominant phylum (No. of individuals: 3011-4839;
relative abundance of 93.6-98.5%, density of 401-645 individual m-2)
followed by the second abundant phylum, arthropods (no. of individuals: 43-201;
relative abundance of 1.2-6.0%, density of 6-27 individual m-2). In addition, other phyla were very low
in abundance across the four sampling zones (relative abundance of <
1%). The number of individuals and
relative abundance (%) of each phylum at every sampling zone were presented in
Table 3.6 of Appendix B.
6.2.6 For TC1,
gastropod Batillaria multiformis was
the most dominant species (64-65 ind. m-2; relative abundance of
33-61%) at upper and middle tidal zones.
Rock oyster Saccostrea cucullata
(12-43 ind. m-2; relative abundance of 15-22%) was the second
abundant species at middle and lower tidal zones. Gastropod Cerithidea djadjariensis was the most dominant species (18 ind. m-2;
relative abundance of 21%) at lower tidal zone while gastropod Batillaria multiformis (12 ind. m-2;
relative abundance of 14%) was the third dominant species at lower tidal zone.
6.2.7 For TC2,
gastropod Cerithidea djadjariensis
was the most dominant species at all tidal zones (31-60 ind. m-2;
relative abundance of 36-51%). The
rock oyster Saccostrea cucullata (32
ind. m-2; relative abundance of 19%) was the second abundant species
at middle tidal zone.
6.2.8 For TC3,
gastropod Cerithidea djadjariensis
(45-83 ind. m-2; relative abundance of 27-47%) and Batillaria multiformis (44-61 ind. m-2;
relative abundance of 25-36%) were the two most dominant species at upper and
middle tidal zones. Rocky oyster Saccostrea cucullata (44 ind. m-2;
relative abundance of 30%) and gastropod Monodonta
labio (36 ind. m-2; relative abundance of 24%) were the most
dominant species at lower tidal zone.
6.2.9 For ST,
the upper tidal zone was dominated by gastropod Batillaria multiformis (40 ind. m-2; relative abundance
of 26%) and Nassarius festivus (32
ind. m-2; relative abundance of 21%). Gastropod Cerithidea djadjariensis (35 ind. m-2; relative
abundance of 33%) was the first dominant species at middle tidal zone and
second dominant species (10 ind. m-2; relative abundance of 20%) at
lower tidal zone. At middle tidal
zone, the gastropod Cerithidea cingulata
was the second abundant species (23 ind. m-2; relative abundance of
22%). At lower tidal zone, rocky
oyster Saccostrea cucullata was the
most dominant species (18 ind. m-2; relative abundance of 37%).
6.2.10 There was
no consistent pattern of species distribution observed across sampling zones
and tidal levels in Tung Chung Wan and San Tau. The species distribution might be
determined by the type of substratum.
In general, gastropod Batillaria
multiformis, Cerithidea djadjariensis
and rocky oyster Saccostrea cucullata
were the most common occurring species among the four sampling zones. The abundant species (relative abundance
>10%) at every sampling zone is presented in Table 3.7 of Appendix B.
6.2.11 The mean
values of number of species, density, H’
and J at every sampling zone are
presented in Table 3.8 of Appendix B. There was no obvious difference across
the three tidal zones and sampling zones.
The number of species ranged 7-12, 5-9, 7-9 and 5-9 spp. 0.25 m-2
at TC1, TC2, TC3 and ST respectively.
The mean density ranged 340-780, 258-668, 587-705 and 192-612 ind. m-2
at TC1, TC2, TC3 and ST respectively.
The H’ ranged 1.06-1.65,
0.93-1.43, 1.04-1.31 and 0.95-1.59 at TC1, TC2, TC3 and ST respectively. The J
ranged 0.54-0.73, 0.57-0.67, 0.55-0.60 and 0.61-0.73 at TC1, TC2, TC3 and ST
respectively. In general, there was
no obvious difference of biodiversity among the four sampling zones based on
the mean H’ and J across tidal zones.
The values reflected a stable intertidal soft shore community with
moderate ecological functions.
6.3
Water Quality Monitoring
6.3.1 The
mudflat monitoring covered water quality monitoring data. Reference was made to the water quality
baseline 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 Appendix A.
6.3.2 Baseline
water quality monitoring in San Tau (monitoring station SR3) was conducted in
October 2011 prior to the construction of the HZMB. The monitoring parameters included
dissolved oxygen (DO), turbidity and suspended solids (SS).
6.3.3 The
baseline monitoring results for SR3 were extracted from the BEMR and summarised
below:
Table 6.2 Baseline
Water Quality Monitoring Results (Depth Average)
|
Date
|
Mid Ebb Tide
|
Mid Flood Tide
|
|
DO Saturation
(%)
|
DO (mg/L)
|
Turbidity (NTU)
|
SS (mg/L)
|
DO Saturation
(%)
|
DO (mg/L)
|
Turbidity (NTU)
|
SS (mg/L)
|
|
6 Oct 2011
|
87.6
|
6.0
|
7.3
|
15.5
|
91.1
|
6.2
|
9.4
|
7.6
|
|
8 Oct 2011
|
89.2
|
6.0
|
4.6
|
7.4
|
95.7
|
6.4
|
9.7
|
12.0
|
|
10 Oct 2011
|
92.1
|
6.2
|
6.3
|
11.0
|
93.9
|
6.3
|
8.5
|
14.0
|
|
12 Oct 2011
|
100.4
|
7.2
|
5.6
|
6.7
|
92.8
|
6.6
|
7.7
|
11.5
|
|
14 Oct 2011
|
91.4
|
6.4
|
9.1
|
10.0
|
88.2
|
6.2
|
10.5
|
16.5
|
|
16 Oct 2011
|
96.9
|
6.8
|
14.1
|
13.0
|
91.0
|
6.5
|
8.5
|
9.7
|
|
18 Oct 2011
|
85.6
|
6.5
|
7.0
|
16.0
|
85.3
|
6.5
|
9.4
|
14.5
|
|
22 Oct 2011
|
93.2
|
7.4
|
9.2
|
12.5
|
92.5
|
7.3
|
10.3
|
18.0
|
|
25 Oct 2011
|
89.8
|
7.2
|
8.4
|
8.3
|
88.4
|
7.1
|
17.8
|
28.0
|
|
27 Oct 2011
|
94.1
|
6.4
|
6.4
|
31.0
|
100.7
|
6.9
|
19.7
|
20.5
|
|
29 Oct 2011
|
120.6
|
8.1
|
8.1
|
15.0
|
106.1
|
7.3
|
14.1
|
22.0
|
|
31 Oct 2011
|
84.1
|
6.8
|
6.8
|
21.0
|
88.8
|
7.1
|
19.0
|
21.0
|
|
Average
|
93.8
|
6.8
|
7.7
|
14.0
|
92.9
|
6.7
|
12.1
|
16.3
|
6.4
Sedimentation Rate Monitoring
Methodology
6.4.1 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.
6.4.2 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 was 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 global
navigation satellite system. The
coordinates system was in HK1980 GRID system. The reference control station was
surveyed and established by traditional land surveying methods using
professional surveying instruments such as total station, level and/or geodetic
GNSS. The accuracy was down to mm
level and higher than the proposed RTK GNSS cm 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.
6.4.3 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
6.4.4 Four monitoring
stations were established based on the site conditions for the sedimentation
monitoring and are shown in Figure 6.1.
Monitoring
Results
6.4.5 The
mudflat surface levels at the four established monitoring stations and the
corresponding XYZ HK1980 GRID coordinates are presented in Table 6.3.
Table 6.3 Measured Mudflat Surface Level Results
|
Monitoring Station
|
Easting (m)
|
Northing (m)
|
Sedimentation Rate
(mPD)
|
Remarks
|
|
S1
|
810291.160
|
816678.727
|
0.950
|
Soft
mudflat
|
|
S2
|
810958.272
|
815831.531
|
0.864
|
Soft
mudflat
|
|
S3
|
810716.585
|
815953.308
|
1.341
|
Soft
mudflat
|
|
S4
|
811221.433
|
816151.381
|
0.931
|
Soft
mudflat
|
6.5
Event and Action Plan for Mudflat Monitoring
6.5.1 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 6.4, should
be undertaken within a period of 1 month after a significant difference has
been determined.
Table 6.4 Event
and Action Plan for Mudflat Monitoring
|
Event
|
ET
|
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 – Environmental Team
IEC – Independent Environmental Checker
SO – Supervising Officer
7.1.1
The baseline monitoring results for air quality,
noise, water quality and ecology (Chinese White Dolphin) undertaken for Agreement No. CE35/2011 (EP) Baseline Environmental
monitoring for Hong Kong – Zhuhai – Macao Bridge Hong Kong Projects –
Investigation has been adopted for the Contract as the baseline monitoring
stations and requirements for the Contract are the same as those presented in
the BEMR.
7.1.2
For the water quality monitoring as required for
mudflat monitoring, reference was made to the water quality baseline monitoring
data of the representative water quality monitoring station (i.e. SR3) as
required in the EM&A Manual.
Baseline water quality monitoring in San Tau (monitoring station, SR3)
was conducted in October 2011 prior to the construction of the HZMB. The monitoring parameters included DO,
turbidity and SS.
7.1.3
For
horseshoe crab survey under mudflat monitoring, there were 1, 9 and 16
individuals of Tachypleus tridentatus as observed at sampling zones, TC1, TC3 and ST,
respectively during the survey.
Indeed, all horseshoe crabs, Tachypleus
tridentatus, were in ages of 9 months to 8 years old based on the
measurements of their prosomal widths.
7.1.4
Only
one species of seagrass, Halophila ovalis,
was recorded at one sampling zone, ST during the seagrass beds survey. Four patches of this species of seagrass
were observed and their estimated areas were also recorded of which the
estimated total area was about 332.3m2.
7.1.5
For
intertidal soft shore communities survey under mudflat monitoring, a total of 15,188 individuals were
recorded. Mollusks were
significantly abundant phylum (total individuals of 14,669; relative abundance of
96.6%) followed by the second abundant group, arthropod (total individuals of
467; relative abundance of 3.1%) at the sampling zones.
7.1.6
Measurement
of the mudflat surface level were conducted at four monitoring stations, S1,
S2, S3 and S4, to establish the baseline level prior to the commencement of the
construction works. The mudflat
sedimentation rate at S1, S2, S3, and S4 were 0.950mPD, 0.864mPD, 1.341mPD and
0.931mPD, respectively.
Environmental Monitoring Stations
Intertidal Soft Shore Communities Survey Results
Draft Final Report on Baseline Chinese White
Dolphin Monitoring for
Hong Kong – Zhuhai – Macao Bridge Hong Kong Projects
