4
Environmental
monitoring Results
4.1
The monitoring results for 1-hour TSP and 24-hour
TSP are summarized in Table 4.1 and 4.2 respectively.
Graphical presentations of
1-hour and 24-hour TSP monitoring results are shown in Appendices B
and C respectively.
Table 4.1 Summary Table of 1-hour TSP
Monitoring
Results during the Reporting Period
|
Month |
Monitoring Station |
Concentration (µg/m3) |
Action Level, µg/m3 |
Limit Level, µg/m3 |
|
|
Average |
Range |
||||
|
September 2018 |
AMS1 |
39 |
8 ¡V 82 |
381 |
500 |
|
AMS4 |
26 |
4 ¡V 58 |
352 |
||
|
October 2018 |
AMS1 |
90 |
53 ¡V 191 |
381 |
|
|
AMS4 |
58 |
33 ¡V 139 |
352 |
||
Table 4.2 Summary Table of 24-hour TSP Monitoring
Results during the Reporting Period
|
Month |
Monitoring Station |
Concentration (µg/m3) |
Action Level, µg/m3 |
Limit Level, µg/m3 |
|
|
Average |
Range |
||||
|
September 2018 |
AMS1 |
22 |
18 ¡V 28 |
170 |
260 |
|
AMS4 |
21 |
12 ¡V 34 |
171 |
||
|
October 2018 |
AMS1 |
49 |
42 ¡V 61 |
170 |
|
|
AMS4 |
31 |
30 ¡V 32 |
171 |
||
4.2
According to our field observations, the major dust
source identified at the designated air quality monitoring stations in the
reporting period are as follows:
Table 4.3 Observation
at Dust Monitoring Stations
|
Monitoring Station |
Major Dust Source |
|
AMS1 |
Exhaust from marine traffic |
|
AMS4 |
N/A |
4.3
The wind data monitoring results were attached in
the Monthly EM&A Reports
4.4
The noise monitoring results are summarized in Table 4.4. Graphical presentations of noise monitoring are shown in Appendix D.
Table 4.4 Summary Table of Noise
Monitoring
Results during the Reporting Period
|
Month |
Monitoring Station |
Noise Level, Leq (30min) dB(A) |
Limit Level |
|
|
Average |
Range |
|||
|
September 2018 |
NMS1 |
71 |
69 ¡V 72 |
75 dB(A) |
|
NMS4 |
55 |
53 ¡V 58 |
||
|
October 2018 |
NMS1 |
73 |
70 ¡V 75 |
|
|
NMS4 |
58 |
55 ¡V 60 |
||
Remark: +3dB(A) Façade correction included
4.5
According to our field observations, the major noise
source identified at the designated noise monitoring stations in the reporting
period are as follows:
Table 4.5 Observation at Noise
Monitoring Stations
|
Monitoring Station |
Major Noise Source |
|
NMS1 |
Air traffic & marine traffic noise |
|
NMS4 |
Air traffic & marine traffic noise |
4.6
The graphical presentation of water quality at the
monitoring stations is shown in Appendix
E.
4.7
Water quality impact sources during the water
quality monitoring were the construction activities of the Contract, nearby
construction activities by other parties and nearby operating vessels by other
parties.
Summary of survey effort and dolphin
sightings
4.8
During the period
of September to October 2018, four sets of systematic line-transect vessel
surveys were conducted to cover all transect lines in WL survey area twice per
month.
4.9
From these
surveys, a total of 129.99 km of survey effort was collected, with 100% of the
total survey effort being conducted under favourable
weather conditions (i.e. Beaufort Sea State 3 or below with good
visibility). The total survey
effort conducted on primary lines was 86.29 km, while the effort on secondary
lines was 43.70 km. Survey effort
conducted on primary and secondary lines were both considered as on-effort
survey data. A summary table of the
survey effort is shown in Appendix I of
Appendix F.
4.10
During the four
sets of monitoring surveys in September to October 2018, a total of 24 groups
of 93 Chinese White Dolphins were sighted.
All dolphin sightings were made during on-effort search. Fifteen on-effort sightings were made on
primary lines, while the other nine on-effort sightings were made on secondary
lines. A summary table of the
dolphin sightings is shown in Appendix
II of Appendix F.
Distribution
4.11
Distribution of dolphin sightings made during
HKLR09 monitoring surveys from September to October 2018 is shown in Figure 1 of Appendix F. The majority of dolphin sightings were
concentrated in the central and southern portions of WL survey area, or mainly
between Kai Kung Shan and Fan Lau (Figure
1 of Appendix F). A few more
sightings were made to the north of Tai O Peninsula, while the dolphins
appeared to avoid the waters between Tai O Peninsula and Kai Kung Shan, as well
as the northern end of the WL survey area (Figure
1 of Appendix F).
4.12
Sighting distribution of dolphins in the present
quarter was quite different from the one during the baseline period in
September to November 2011, when the dolphins were mainly concentrated in
waters between Tai O Peninsula and Kai Kung Shan, especially in the offshore
waters overlapping the western Hong Kong territorial boundary (Figure 1 of Appendix F).
Moreover, dolphins rarely occurred near Fan Lau Peninsula during the
present quarter, where a number of dolphin sightings clustered around this area
during the baseline period (Figure 1 of
Appendix F).
4.13
Dolphins appeared to avoid the HKLR09 alignment during
the present quarterly period, which was not the case in the previous two
quarters. As the disturbance arisen
from the HKLR09 construction activities on the dolphins have been completed,
dolphins are expected to utilize the waters in the vicinity of the bridge
alignment more. It may still be
premature to conclude whether the potential obstruction from the permanent
physical structure of the bridge piers has lingered or not, and this critical
issue should be continuously examined in the upcoming quarters through both
boat surveys and land-based theodolite tracking surveys during the operational
phase of the EM&A programme.
4.14
Distribution patterns of dolphin sightings in the
past three autumn quarters of 2015-17 were compared with the one in 2018. Unlike the previous three autumn periods
in 2015-17 with more even distribution, dolphin distribution was more
concentrated in the southern portion of the WL survey area (Figure 3 of Appendix F). On the other hand, dolphins have
consistently avoided the HKLR09 alignment in the past three autumn periods in
2016-18 (Figure 3 of Appendix F).
Encounter rate
4.15
During the present impact phase monitoring quarter
(September ¡V October 2018), the encounter rates of Chinese White Dolphins
deduced from the survey effort and on-effort sighting data from the primary
transect lines under favourable conditions (Beaufort
3 or below) from West Lantau survey area are shown in Table 4.6. The average
encounter rates deduced from the four sets of surveys from the present quarter
were also compared with the ones deduced from the baseline monitoring period
(September ¡V November 2011) (Table 4.7).
Table
4.6 Dolphin encounter rates (sightings per
100 km of survey effort) during the impact monitoring period (September to
October 2018)
|
Survey Area |
Dolphin Monitoring |
Encounter rate (STG) |
Encounter rate (ANI) |
|
Primary Lines Only |
Primary Lines Only |
||
|
West Lantau |
Set 1 (September 5th) |
14.6 |
82.6 |
|
Set 2 (September 11th) |
21.8 |
113.3 |
|
|
Set 3 (October 2nd) |
18.7 |
84.0 |
|
|
Set 4 (October 9th) |
14.0 |
37.5 |
Table
4.7 Comparison of average dolphin encounter
rates from impact monitoring period (September to October 2018) and baseline
monitoring period (September-November 2011)
|
|
(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) |
||
|
September ¡V
October 2018 |
September- November 2011 |
September ¡V
October 2018 |
September- November 2011 |
|
|
West Lantau |
17.27 ¡Ó 3.65 |
16.43¡Ó 7.70 |
79.36 ¡Ó 31.30 |
60.50¡Ó 38.47 |
4.16
Notably, the
encounter rates of dolphin sightings (ER(STG)) and
encounter rates of dolphins (ER(ANI)) in the present quarter (September to
October 2018) were the fifth and fourth highest respectively during the entire
construction period, and the ER(ANI) and ER(STG) in this autumn quarter was the
highest and second highest respectively among the seven autumn periods in
2011-18 (Table 4 of Appendix F). In fact, those encounter
rates in the present quarter were even higher than the baseline ones recorded
in 2011 (Table 4 of Appendix F). Such noticeable rebound in the present
quarter (as well as in the previous quarter) should be continuously monitored
in the upcoming quarter, to confirm whether the increase in dolphin occurrence
in WL survey area in recent months is temporary or persistent.
4.17
A one-way ANOVA was
conducted to examine whether there were any significant differences in the
average encounter rates between the baseline and impact monitoring
periods. For the comparison between
the baseline period and the present quarter (i.e. the 22nd quarter of the
impact phase), the p-value for the differences in average dolphin encounter
rates of STG and ANI were 0.846 and 0.440 respectively. Therefore, if the alpha value is set at
0.05, significant difference was not detected between the baseline period and
the present quarter in both encounter rates of STG and ANI.
4.18
Another comparison
was made between the baseline period and the 22 cumulative quarters in the
impact phase, and the p-value for the differences in average dolphin encounter
rates of STG and ANI were 0.476 and 0.635 respectively. As a result, no significant difference
was found in the dolphin encounter rates between the baseline period and the
cumulative quarters in the impact phase.
Group size
4.19
Group size of
Chinese White Dolphins ranged from one to twelve individuals per group in WL
survey area during September to October 2018. The average dolphin group size for the
two-month period was compared with the one deduced from the baseline period in
September to November 2011, as shown in Table
4.8.
Table
4.8 Comparison of average dolphin group
sizes from impact monitoring period (September to October 2018) and baseline monitoring
period (September-November 2011)
|
|
Average Dolphin Group Size |
|
|
September ¡V October
2018 |
September ¡V November 2011 |
|
|
West Lantau |
3.88 ¡Ó
3.07 (n = 24) |
3.63 ¡Ó 2.97 (n = 46) |
4.20
The average dolphin
group size in the WL region during the present quarter was slightly higher than
the one recorded during the three-month baseline period (Table 4.8). Among the
24 groups, 15 of them were composed of only 1-4 dolphins, while there were
eight groups in moderate size with 5-9 dolphins, and only one large group with
12 animals.
4.21
Distribution of
dolphins with larger group sizes (with five or more animals per group) during
September to October 2018 is shown in Figure
4 of Appendix F. Besides the large
group of animals sighted to the west of Peaked Hill, the other medium- sized
groups of dolphins were mostly distributed in waters to the west of Kai Kung
Shan and Fan Lau (Figure 4 of Appendix F). This was very different from the
baseline phase when the larger dolphin groups were mostly concentrated near Tai
O Peninsula and Kai Kung Shan (Figure 4
of Appendix F).
Habitat use
4.22
From September to October 2018, the grids that
recorded higher densities of dolphins were located near Tai O Peninsula, Kai
Kung Shan, Peaked Hill and Tai O (Figures
5a & 5b of Appendix F).
4.23
However, it should be cautioned that the amount of
survey effort collected in each grid during the two-month period was very low
(only four units of survey effort for most grids), and therefore the habitat
use pattern derived from the two-month dataset should be treated with extra
caution.
4.24
When compared with the habitat use pattern recorded
during the baseline period in September-November 2011, it appears that the overall
dolphin occurrence was much lower in the waters between Tai O Peninsula and Kai
Kung Shan as well as to the north and northwest of Tai O Peninsula during the
present impact phase monitoring period in autumn 2018 (Figure 6 of Appendix F).
Mother-calf pairs
4.25
During the
two-month impact phase monitoring period, only one young calf (an unspotted
calf) was sighted in the WL survey area.
The single calf comprised only 1.1% of all animals sighted, which was
much lower than the percentage recorded during the baseline monitoring period
(6.6%).
4.26
The unspotted calf
occurred with its mother to the west of Kai Kung Shan during this quarter, and
the calf occurrence was very different from the baseline period when that was
much more frequent and concentrated in the northern portion of WL waters near
Tai O Peninsula (Figure 7 of Appendix F).
Activities and associations with fishing boats
4.27
During the present impact monitoring period, only
one dolphin group was engaged in socializing activity to the west of Peaked Hill
(Figure 8 of Appendix F). On the other hand, none of the dolphin
groups was observed to be engaged in feeding, traveling or milling/resting
activity in this quarter.
4.28
Distribution of different activities engaged by the
dolphins during the present impact phase monitoring period was drastically
different from the one during the baseline period, when the main concentration
of feeding and socializing activities occurred more often between Tai O
Peninsula and Peaked Hill (Figure 8 of
Appendix F).
4.29
During the two-month monitoring period, none of the
24 dolphin groups was associated with any operating fishing boat (Appendix II of Appendix F).
Summary of photo-identification works
4.30
From September to October 2018, over 3,000 digital
photographs of Chinese White Dolphins were taken during the impact phase
monitoring surveys for the photo-identification work.
4.31
In total, 50 individuals sighted 69 times
altogether were identified (see the summary table in Appendix III of Appendix F and photographs of identified
individuals in Appendix IV of Appendix F). The majority of these individuals were
re-sighted only once during the two-month period. However, there were a total of ten
individuals (NL256, SL44, WL61, WL79, WL92, WL130, WL131, WL220, WL230 and
WL293) being re-sighted twice, and another four individuals being re-sighted
3-4 times (NL225, NL269, WL109 and WL152) (Appendix
III of Appendix F).
4.32
Among the 50 identified individual dolphins,
surprisingly none of them was re-sighted in North Lantau waters during
HKLR03/HKBCF monitoring surveys during the same period, which was drastically
different from the previous monitoring quarters during the HKLR09 construction
with regular occurrence of identified individuals across the bridge alignment.
4.33
Notably,
a number of individuals (e.g. NL33, NL145, NL210, NL233, NL242)
were consistently sighted in North Lantau waters in the past, but were only
re-sighted in WL waters during the present quarterly period.
Individual range use
4.34
Ranging patterns of the 50 individuals
identified during the two-month study period were determined by fixed kernel
method, as shown in Appendix V of
Appendix F.
4.35
As in previous monitoring quarters, the
majority of identified individuals that primarily centered their range use in
West Lantau were still sighted within their normal ranges during the present
quarterly period, while none of them has extended their range use from WL
waters to the northern part of Lantau waters (Appendix V of Appendix F).
Conclusion
4.36
During the present quarter of dolphin monitoring,
no adverse impact from the activities of the HKLR09 construction project on
Chinese White Dolphins was noticeable from general observations.
4.37
Nevertheless, the dolphin usage in WL region should
be continuously monitored during the operational phase of HZMB, to further
examine whether the dolphins are still affected by the lingering impacts from
the bridge construction works in the near future.
Post-construction dolphin monitoring has been
started after completion of construction according to the updated EM&A Manual Section 10.7.1.
Dolphin line-transect survey was carried out twice
a month in November 2018. Detailed monitoring methodology and results can be
found in the Monthly EM&A Report.
4.38
According to Section 10 of approved EIA Report,
EM&A Manual and Section 2 of approved Proposal for Land-based Dolphin
Behavior and Movement Monitoring submitted on 24 January 2013 and approved by
the authority on 5 February 2013, land-based theodolite tracking to study
dolphin behaviour near bored piling work site, and
examine their north-south movement across the bridge alignment shall be
conducted before, during and after bridge construction. Summary of the
requirements of land-based dolphin monitoring is shown in Table 4.9:
Table 4.9 Summary of
Land-based of Dolphin Behaviour and Movement
Monitoring Requirements
|
EIA |
EM&A Manual |
Approved
Monitoring Proposal |
|
Requirement for
Land-based of dolphin behaviour and movement
monitoring |
||
|
Ÿ Land-based
theodolite tracking to study dolphin behaviour near bored piling work site,
and examine their north-south movement across the bridge
alignment before, during and after bridge construction. |
Ÿ Land-based
theodolite tracking to study dolphin behaviour near bored piling work site,
and examine their north-south movement across the bridge alignment before, during and after bridge
construction. Ÿ The behaviour near
the bored piling sites and north-south movement across the bridge alignment
of CWD should be monitored in the waters to the west of Airport. |
Ÿ Dolphin behaviour
in response to bored piling works and movement near the bored piling sites
should be monitored at the first three pier sites for 30 days from the
start of bored piling activities in the waters to the west of Airport.
However, the number of monitoring days is not well specified for the baseline
period. Ÿ Therefore,
reference to the requirements in the Tuen Mun ¡V Chek Lap Kok Link (TMCLKL) EM&A Manual was made, in which 30
days of theodolite tracking before(i) and 30 days of theodolite tracking from the start of
bored piling activities(ii) will be conducted under the present study in order
to maintain overall consistency of EM&A Programs for the Hong
Kong-Zhuhai-Macao Bridge (HZMB) development. |
|
Frequency |
||
|
Baseline |
||
|
Ÿ Not specified |
Ÿ Baseline
for dolphin north-south movement across the bridge alignment shall be
established prior to the commencement of works and agreed with AFCD. |
Ÿ 30 consecutive days (with 5-6 hours on each survey day). Ÿ It should be noted
that every attempt will be made to conduct the monitoring in favorable weather conditions (Beaufort Sea State 3 or
below; good visibility of 2km or above). |
|
Impact |
||
|
Ÿ Not specified |
Ÿ Dolphin behavior in response to bored piling and movement near
the bored piling sites will be monitored at the three pier sites for 30 days
from the start of bored piling activities in the waters to the west of
Airport. |
Ÿ 30 consecutive
days (with 5-6 hours on each survey day).
Ÿ It should be noted
that every attempt will be made to conduct the monitoring in favorable weather conditions (Beaufort Sea State 3 or
below; good visibility of 2km or above). Ÿ In the proposal,
the dolphin specialist has also proposed an additional 64 days of monitoring
(twice per month, with 5-6 hours on each survey day) throughout the
construction period to examine the impact of bridge construction on
north-south movement of CWD across the bridge alignment. |
|
Post-construction |
||
|
Ÿ Not specified |
Ÿ Not specified |
Not specified |
4.39
The major construction programme
of the Contract is provided in Table
4.10.
Table
4.10 Major
Construction Program for Contract No. HY/ 2011/09
|
Description |
Period |
|
Commencement of the
Contract |
May 2012 |
|
Construction Commencement |
February 2013 |
|
Piling |
April 2013 ¡V September
2015 |
|
Pile Cap and Piers |
December 2013 ¡V May 2016 |
|
March 2015 ¡V June 2017 |
4.40
Based on the construction programme
in Section 4.39, Land-based theodolite monitoring after bridge construction has
been conducted twice per month from September 2016 to August 2018. A total of
48 days of monitoring was carried out after the impact monitoring completion.
Summary of Land-based dolphin behavior and movement monitoring across the
bridge alignment before, during and after bridge construction are presented in Table 4.11.
Table 4.11 Summary of Land-based dolphin behavior and
movement monitoring across the bridge alignment before, during and after bridge
construction
|
Land-based dolphin
behavior and movement monitoring |
Monitoring Period |
Monitoring Details |
|
Baseline (before bridge
construction) |
Dec 2012 ¡V Jan 2013 |
i)
30 consecutive days before bridge construction
(i.e. before start of bored piling activities) |
|
Impact (during bridge
construction) |
Mar 2013 ¡V Aug 2016 |
i)
30 days from the start of bored piling activities
in the waters to the west of Airport; and ii)
64 days (twice per month) throughout the bridge
construction period (Remark: the pile cap and pier construction under
Contract HY/2011/09 were completed in May 2016) |
|
Post-construction (after bridge construction) |
Sept 2016 ¡V August 2018 |
i)
48 days (twice per month) after completion of
bored piling activities |
4.41
The Land-based Dolphin Behavior and Movement
Monitoring for ¡§baseline¡¨, ¡§impact¡¨ and ¡§after bridge construction¡¨ have been
conducted by the same dolphin specialist using consistent monitoring
methodology and result analysis.
4.42
Details of Land-based dolphin behavior and movement
monitoring after bridge construction are presented in the separate Final Report
of Land-based Monitoring on North-South Movement of Chinese White Dolphins in
West Lantau Waters (After Bridge Construction).
4.43
All Land-based Dolphin Behaviour
and Movement Monitoring have been completed under Contract No. HY/2011/09 and
had fulfilled the requirements stated in the EM&A Manual.
Advice
on the Solid and Liquid Waste Management Status
4.44
The Contractor was advised to minimize the
wastes generated through the recycling or reusing. All mitigation measures
stipulated in approved waste management plan shall be fully implemented.
4.45
The amount of wastes generated by the
activities of the Contract during the reporting month is shown in Appendix J.