Contents
1.1 Purpose of the Report
1.2 Structure of the Report
2.1 Background
2.2 Site Description
2.3 Status of Environmental Approval Documents
3 Water
Quality Monitoring Requirements
3.1 Monitoring Locations
3.2 Monitoring Parameters
3.3 Monitoring Equipment and Methodology
4 IMPLEMENTATION
STATUS OF ENVIRONMENTAL MITIGATION measures
5 Post
Project Monitoring Results
LIST
OF TABLES
Table
2.1 Summary of Environmental
Licensing, Notification, Permit and Reporting Status
Table 3.1 Co-ordinates of Water
Quality Impact Monitoring Stations in Zone A, Zone B and Zone C
Table
3.2 Equipment Used during the
Impact Water Quality Monitoring
LIST
OF ANNEXES
Annex A |
|
Annex B |
|
Annex C |
The submarine-cable
installation works for the Asia
Submarine-cable Express (ASE) cable system commenced in October 2012 and were completed in
January 2013. This is the Post Project Water Quality Monitoring Report
presenting the post-project water quality monitoring conducted during the
period from 4 February 2013 to 20 February 2013 in accordance with the
Monitoring
and Audit Manual (EM&A Manual).
Water Quality
Nine monitoring events (days) were
scheduled between 4
February 2013 and 20 February 2013,
with three days for each of Zone A, Zone B and Zone C. Monitoring events at all designated
monitoring stations in the three zones were performed on schedule.
In general, the dissolved oxygen
levels recorded during the Post Project Monitoring period were mostly higher to
the results obtained during the baseline monitoring period. Turbidity and suspended solid levels in Post
Project Monitoring period were also slightly increased at all designated
stations including the control stations.
After detailed analysis, it is considered that the overall changes in turbidity
and SS were driven by natural fluctuations rather than the marine works of the
Project.
Conclusion
Upon
completion of the Project, overall water quality at the impact stations in Zone
A, Zone B and Zone C was found to be similar to that
at control stations, which was higher in dissolved oxygen, turbidity and
suspended solids when compared with the baseline data. Given the fact that control stations are
sufficiently far away from the cable alignment and water quality at these stations could not be affected by the Project, it is
concluded that the overall variations in turbidity
and SS reflected a natural phenomenon.
Hence, no
deterioration of water quality was observed other than natural fluctuation. The impact of the marine works of the
Project on water quality is considered to be negligible.
ERM-Hong Kong, Limited
(ERM) was appointed by NTT Com Asia (NTTCA) as the Environmental Team (ET) to
implement the Environmental Monitoring and Audit (EM&A) programme for the installation
of a telecommunication cable (Asia-Submarine-cable Express (ASE)) of
approximately 7,200 km in length, connecting Japan and Singapore with branches
to the Philippines, Hong Kong SAR (HKSAR) and Malaysia (thereinafter called the Project).
This is the Post
Project Water Quality Monitoring Report, which summarises the results
of post-project water quality monitoring finding as part of the EM&A
programme during the reporting period from 4 February
2013 to 20 February 2013. The Post
Project Monitoring results are used to compare with the baseline monitoring
results in order to investigate the impact of the project works on water
quality in the vicinity of the project site from Tseung
Kwan O eastward to the boundary of HKSAR waters.
The structure of the Report
is as follows:
Section
1 : Introduction
Provides details of the background,
purpose and report structure.
Section 2 : Project
Information
Summarises background and scope of the project, the
construction works undertaken and the status of Environmental Permits/Licenses
during the reporting period.
Section
3 : Water
Quality Monitoring Requirements
Summarises
the monitoring parameters, monitoring programmes, monitoring methodologies,
monitoring frequency, and monitoring locations.
Section
4 : Implementation
Status of Environmental Mitigation Measures
Summarises the implementation of
environmental protection measures during the reporting period.
Section
5 : Post
Project Monitoring Results
Summarises the monitoring results obtained in the
reporting period for Zone A, Zone B and Zone C.
Section
6 : Conclusions
Presents
the key findings of the Post Project Monitoring results.
NTT Com Asia (NTTCA) proposed to install a
telecommunication cable (Asia Submarine-cable Express (ASE) cable) of
approximately 7,200 km in length, connecting Japan and Singapore with branches
to the Philippines, Hong Kong SAR (HKSAR) and Malaysia. NTTCA is responsible for securing the
approval to land the ASE cable in Tseung Kwan O, Hong
Kong SAR (HKSAR). The landing site is
at a new Beach Manhole (BMH) and the cable is ultimately connected with a Data
Centre in Tseung Kwan O (TKO) Industrial Estate. From Tseung
Kwan O, the cable extends westward approaching the Tathong
Channel. Near to Cape Collinson, the cable is approximately parallel to the Tathong Channel until north of Waglan
Island where the cable travels eastward to the boundary of HKSAR waters where
it enters the South China Sea. The
total length of cable in Hong Kong SAR waters is approximately 33.5 km. A map of the cable route is presented in
Figure
2.1.
A
Project Profile (PP-452/2011) which includes an assessment of the potential
environmental impacts associated with the installation of the submarine
telecommunications cable system was prepared and submitted to the Environmental
Protection Department (EPD) under section 5. (1)(b)
and 5.(11) of the Environmental Impact Assessment Ordinance (EIAO) for the
application for Permission to apply directly for Environmental Permit
(EP). The Environmental Protection
Department, subsequently issued an Environmental Permit (EP- 433/2011).
Pursuant
to Condition 2.4 of the EP, an environmental monitoring and audit programme as
set out in the Environmental Monitoring
and Audit Manual (EM&A Manual)
is required to be implemented. In
accordance with Section 2.3 of the EM&A
Manual, Post Project Monitoring of marine water
quality should be undertaken after completion of the cable installation works
at the same stations as baseline monitoring in Zone A, Zone B and Zone C,
during mid-flood and mid-ebb tides.
Baseline
Monitoring was conducted in Zone A between 29 August 2012 and 3 September 2012
and the results were presented in Baseline
Water Quality Monitoring Report (Zone A). Baseline monitoring for Zone B was
undertaken from 17 September 2012 to 21 September 2012 and Baseline Water Quality Monitoring Report (Zone B) presented the
results of the monitoring data in Zone B.
Baseline monitoring was as well as carried out in Zone C between 24
September 2012 and 28 September 2012 and the results were presented in Baseline Water Quality Monitoring Report
(Zone C).
Impact Monitoring in Zone
A, Zone B and Zone C commenced on 8 October 2012 when the cable installation
barge started to work in Zone A. The
cable installation works were completed on 29 December 2012 and the impact
water quality monitoring ceased subsequently.
All marine works for the cable installation was
completed in January 2013. In
accordance with the EM&A
Manual ,
Post Project Water Quality Monitoring Report should be conducted within one
month after completion of the marine works in Zone A, Zone B and Zone C. This report presents the data obtained
from Zone A (Figure 2.2), Zone B (Figure 2.3) and Zone C (Figure 2.4). Results
of the Post Project Monitoring data have been compared against the results of
the baseline water quality monitoring in each zone.
The
cable installation ran from Tseung Kwan O, and extended
eastward approaching the Tathong Channel. Near to Cape Collinson,
the cable is approximately parallel to the Tathong
Channel until north of Waglan Island where the cable
travels eastward to the boundary of HKSAR waters where it enters the South
China Sea. The alignment of the
cable is illustrated in Figure 2.1.
A
summary of the relevant permits, licences and reports on marine water quality
for this Project is presented in Table 2.1.
Table 2.1 Summary
of Environmental Licensing, Notification, Permit and Reporting Status
Permit /
Licence / Notification / Report |
Reference |
Validity
Period |
Remarks |
Environmental
Permit |
EP
433/2011 |
Throughout
the construction and operation stages |
Granted
on 20 December 2011 |
EM&A
Manual |
- |
Throughout
the construction stage |
Revised
EM&A Manual submitted on 18 September 2012 |
Baseline
Water Quality Monitoring Report (Zone A) |
- |
Throughout
the construction period for Zone A |
Submitted
on 19 September 2012 |
Baseline
Water Quality Monitoring Report (Zone B) |
- |
Throughout
the construction period for Zone B |
Submitted
on 25 September 2012 |
Baseline
Water Quality Monitoring Report (Zone C) |
|
Throughout
the construction period for Zone C |
Submitted on 1 October 2012 |
First Weekly Impact Water Quality Monitoring
Report |
|
Throughout
the construction stage |
Submitted on 19 October 2012 |
Second Weekly Impact Water Quality Monitoring
Report |
|
Throughout
the construction stage |
Submitted on 24 October 2012 |
Third Weekly Impact Water Quality Monitoring
Report |
|
Throughout
the construction stage |
Submitted on 24 December 2012 |
Forth Weekly Impact Water Quality Monitoring
Report |
|
Throughout
the construction stage |
Submitted on 8 January 2013 |
In accordance with the EM&A Manual, marine water samples for
Post Project Monitoring were collected at the same stations
as baseline monitoring situated around the submarine cable
works in Zone A, Zone B and Zone C. The locations of the
sampling stations are shown in Figure 2.2
¡V Figure 2.4.
Zone A area:
¡P
C1 is a Control Station (approximately 3 km from the
proposed cable alignment) for Zone A.
It is not supposed to be influenced by the cable laying works due to its
remoteness to the construction works;
¡P
E7 is the Impact Station located at Fat Tong Chau to monitor the impacts of cable installation works on
the coral communities in the proximity;
¡P
E8 is an Impact Station to monitor the impacts of
cable installation works on the coral communities along Junk Bay ¡V South West;
¡P
E9 is an Impact Station to monitor the impacts of
cable installation works on the coral communities at Cape Collison
(the Gradient Station is not set due to the short distance of this Impact
Station to nearby proposed cable works which may affect the cable laying
works);
¡P
F1 is an Impact Station to monitor the impacts of
cable installation works on the Tung Lung Chau Fish
Culture Zone;
¡P
S1 is an Impact Station situated at the WSD Seawater
Intake Point in Junk Bay. It is
located within 500 m north of the cable alignment at Junk Bay and set up to
monitor the effect of cable laying works in the area;
¡P
S2 is an Impact Station to monitor the impacts of
cable installation works on the WSD Seawater Intake at Siu Sai
Wan;
¡P
S3 is an Impact Station to monitor the impacts of
cable installation works on the Pamela Youde Nethersole Eastern Hospital Cooling Water Intake at Heng Fa Chuen;
¡P
G1 is a Gradient Station between S1 and the cable
alignment;
¡P
G2 is a Gradient Station between S2 and the cable
alignment; and
¡P
G3 is a Gradient Station between F1 and the cable
alignment.
Zone
B area:
¡P
C2 is a Control Station (approximately 3.4 km from the
proposed cable alignment) for Zone B.
It is not supposed to be influenced by the cable laying works due to its
remoteness to the construction works;
¡P
B1 is an Impact Station to monitor the impacts of
cable installation works on the
¡P
B2 is an Impact Station to monitor the impacts of
cable installation works on the
¡P
B3 is an Impact Station to monitor the impacts of
cable installation works on the Shek O Beach;
¡P
E1 is an Impact Station to monitor impacts of cable
installation works on
¡P
E2 is an Impact Station to monitor the impacts of
cable installation works on the coral communities at Tung Lung Chau;
¡P
E6 is an Impact Station to monitor the impacts of
cable installation works on the coral communities at Tai Long Pai (the Gradient Station is not set due to the short
distance of this Impact Station to nearby proposed cable works which may affect
the cable laying works);
¡P
E9 is an Impact Station to monitor the impacts of
cable installation works on the coral communities at Cape Collison
(the Gradient Station is not set due to the short distance of this Impact
Station to nearby proposed cable works which may affect the cable laying
works);
¡P
F1 is an Impact Station to monitor the impacts of
cable installation works on the Tung Lung Chau Fish
Culture Zone;
¡P
G3 is a Gradient Station between F1 and the cable
alignment;
¡P
G4 is a Gradient Station between E2 and the cable
alignment; and
¡P
G7 is a Gradient Station between E1 and the cable
alignment.
Zone
C area:
¡P
C3 is a Control Station (approximately 3 km from the
proposed cable alignment) for Zone C.
It is not supposed to be influenced by the cable laying works due to its
remoteness to the construction works;
¡P
E4 is the Impact Station to monitor the impacts of
cable installation works on the coral communities at the coast of Sung Kong;
¡P
E5 is the Impact Station to monitor the impacts of
cable installation works on the coral communities at the coast of Waglan Island;
¡P
G5 is the Gradient Station between E4 and the
alignment; and
¡P
G6 is the Gradient Station between E5 and the
alignment.
The
co-ordinates of the above monitoring stations in Zone A,
Zone B and Zone C are listed in Table 3.1.
Table 3.1 Co-ordinates of Water
Quality Impact Monitoring Stations in Zone A, Zone B and Zone C
Monitoring
Station |
Nature |
Easting |
Northing |
Zone
A |
|||
E7 |
Impact
Station (Coral Community) |
843779 |
814520 |
E8 |
Impact
Station (Coral Community) |
843111 |
815126 |
E9 |
Impact
Station (Coral Community) |
843557 |
811853 |
F1 |
Impact Station (Fish Culture Zone) |
847196 |
811056 |
S1 |
Impact Station (Seawater Intakes) |
847639 |
805900 |
S2 |
Impact Station (Seawater Intakes) |
849587 |
805696 |
S3 |
Impact Station (Seawater Intakes) |
845474 |
810605 |
G1 |
Gradient
Station |
845297 |
816282 |
G2 |
Gradient
Station |
844071 |
814784 |
G3 |
Gradient
Station |
846099 |
812826 |
C1 |
Control
Station |
842022 |
816547 |
Zone
B |
|||
B1 |
Impact
Station (Beach) |
843557 |
811853 |
B2 |
Impact
Station (Beach) |
844062 |
810369 |
B3 |
Impact
Station (Beach) |
843988 |
809902 |
E1 |
Impact
Station (Marine Reserve) |
845474 |
810605 |
E2 |
Impact
Station (Coral Communities) |
845203 |
815205 |
E6 |
Impact
Station (Coral Communities) |
845321 |
816718 |
E9 |
Impact
Station (Coral Communities) |
843557 |
811853 |
F1 |
Impact
Station (Fish Culture Zone) |
847196 |
811056 |
G3 |
Gradient
Station |
846099 |
812826 |
G4 |
Gradient
Station |
846583 |
810809 |
G7 |
Gradient
Station |
845946 |
808583 |
C2 |
Control
Station |
849603 |
811528 |
Zone
C |
|||
E4 |
Impact
Station (Coral Communities) |
843210 |
816322 |
E5 |
Impact
Station (Coral Communities) |
844627 |
813609 |
G5 |
Gradient
Station |
847795 |
806678 |
G6 |
Gradient
Station |
849703 |
806636 |
C3 |
Control
Station |
848556 |
804750 |
The
impact water quality monitoring was conducted in accordance with the
requirements stated in the EM&A
Manual. Monitoring parameters
are presented as below.
Parameters measured in situ were:
¡P
dissolved oxygen (DO) (%
saturation and mg L-1);
¡P
temperature (¢XC);
¡P
turbidity (NTU); and
¡P
salinity (‰).
The only parameter measured
in the laboratory was:
¡P
suspended solids (SS) (mgL-1).
In addition to the water
quality parameters, other relevant data were measured and recorded in field
logs, including the location of the sampling stations, water depth, time,
weather conditions, sea conditions, special phenomena and work activities
undertaken around the monitoring and works area that may influence the
monitoring results.
Table 3.2 summaries
the equipment used for the post project water quality monitoring.
Table 3.2 Equipment
Used during the Post Project Water Quality Monitoring
Equipment |
Model |
Global Positioning Device |
Garmin etrex 10 |
Water Depth Gauge |
Speedtech Instrument SM-5A |
Water Sampling Equipment |
1510 Kemmerer Water
Sampler |
Salinity, DO, Temperature
Measuring Meter |
YSI Pro 2030 |
Current Velocity and
Direction |
Flow Probe FP11 |
Turbidity Meter |
HACH Model 2100Q Turbid
Meter |
The
water monitoring was carried out on nine occasions (days), with three occasions
(days) for each zone (Annex A). The intervals between two sets of
monitoring were not less than 36 hours.
The
water quality sampling was undertaken within a 4 hour window of 2 hour before
and 2 hour after mid flood and mid-ebb tides. The
tidal range selected for the Post Project Monitoring was at least 0.5 m for
both flood and ebb tides as far as practicable.
Reference
were made to the predicted tides at Tai Miu Wan,
which is the tidal station nearest to the Project Site, published on the
website of the Hong Kong Observatory ([1]). Based on
the predicted tidal levels at Tai Miu Wan, the post-project
water quality monitoring was conducted between 4 February 2013 and 20 February 2013,
following the schedule presented in Annex
A. Schedule for Post Project Monitoring has
been submitted to the Contractor, Independent Environmental Checker (IEC),
Engineer Representative (ER) and Environmental Protection Department (EPD) one
week prior to the commencement of the monitoring works.
Each station was sampled and measurements/ water
samples were taken at three depths, namely, 1 m below water surface, mid-depth
and 1 m above sea bed, except where the water depth less than 6 m, the
mid-depth station may be omitted.
For stations that are less than 3 m in depth, only the mid-depth sample
was taken.
For in situ measurements,
duplicate readings were made at each water depth at each station. Duplicate water samples were collected
at each water depth at each station.
All
in situ monitoring instruments were
checked, calibrated and certified by a laboratory accredited under HOKLAS or
any other international accreditation scheme before use, and subsequently
re-calibrated at monthly intervals throughout all stages of the water quality
monitoring. Responses of sensors
and electrodes were checked with certified standard solutions before each use.
For
the on-site calibration of field equipment, the BS 1427: 1993, Guide to Field and On-Site Test Methods for the Analysis
of Waters was observed. Sufficient
stocks of spare parts were maintained for replacements when necessary. Backup monitoring equipment was made
available.
Water
samples for SS measurements were collected in high density polythene bottles,
packed in ice (cooled to 4¢XC without being frozen), and delivered to a HOKLAS
laboratory as soon as possible after collection.
Two
replicate samples were collected from each of the monitoring events for in situ measurement and lab analysis.
All laboratory work was
carried out in a HOKLAS accredited laboratory. Water samples of about 1,000 mL were
collected at the monitoring and control stations for carrying out the
laboratory determinations. The
determination work started within the next working day after collection of the
water samples. The SS laboratory
measurements were provided within 2 days of the sampling event (48 hours). The analyses followed the standard
methods as described in APHA Standard Methods for the Examination of Water and Wastewater, 19th Edition, unless otherwise specified (APHA 2540D for SS).
The QA/QC details were in
accordance with requirements of HOKLAS or another internationally accredited
scheme (Annex
B).
Mitigation measures for
water quality control were recommended in the Project Profile (PP-452/2011) and
Environmental Permit (EP- 433/2011).
The Contractor implemented the following measures during cable
installation:
¡P
A silt curtain around the
shore-end works site were employed in order to reduce the dispersion of
sediments during the cable laying works;
¡P
The crane barge used for
the transport of excavated materials was fitted with tight bottom seals in
order to prevent leakage of material during loading and transport;
¡P
The crane barge was filled
to a level, which ensures that material did not spill over during loading and
transport to the disposal site and that adequate freeboard was maintained to
ensure that the decks were not washed by wave actions;
¡P
The forward speed of the
installation barge will be limited to a maximum of 1 km/ hour;
¡P
Water quality monitoring was
carried out to verify that the project works will not result in any impacts to
water quality, marine ecology and fisheries; and
¡P
Prevention of leakage from
construction equipment to reduce the runoff entering the marine waters was
incorporated as part of good working practices.
A total of nine monitoring occasions
(days) were scheduled in the reporting period in February
2013 (Annex A). Monitoring occasions at all designated
monitoring stations within Zone A (conducted on 4, 6 and 8 February 2013), Zone B (conducted
on 15, 18 and 20 February 2013) and Zone C (conducted on 14, 16 and 19 February
2013) were
performed on schedule. No major
activities influencing the water quality were identified during the reporting
period.
The Post Project Monitoring
data are presented in Annex C and compared with baseline
monitoring results in Figures C1-C18.
As shown in Figures C1-C18, post project monitoring results
in Zone A, Zone B and Zone C have similar trends in all measured parameters in
particular the level of dissolved oxygen, level of turbidity and suspended
solids. Therefore, monitoring
results of these three parameters are discussed together as follows.
The levels of dissolved oxygen
measured during the post-project reporting period in all of the three zones at
different sampling depths were higher than those obtained during the baseline
monitoring periods. Elevation of dissolved
oxygen concentration was detected at all the impact and control stations during
the Post Project Monitoring period.
DO levels recorded at the impact stations were of similar magnitude to
those measured at the control stations (Figures
C1, C2, C4 and C5 for Zone A, Figures C7, C8, C10 and C11 for Zone B, and Figures C13, C14, C16 and
C17 for Zone C).
Levels of turbidity and
suspended solids measured during the post-project reporting period showed
similar trends (Figures C3 and C6 for Zone A, Figures C9 and C12 for
Zone B, and Figures C15 and C18 for Zone C). Both of them in the three zones were elevated
compared to those measured during the baseline monitoring periods. This occurred to all the monitoring stations
including control stations C1, C2 and C3, which are situated at a long distance
from the submarine cable alignment and are not likely to be affected by the Project
works. Turbidity and suspended
solids levels recorded at all the impact stations were of similar magnitude to
those measured at the control stations during Post Project Monitoring period. Actually this overall elevation in the
level of turbidity and SS has been discussed in the Fourth Weekly Impact Water Quality Monitoring Report, which
concluded the situation as a natural phenomenon and an overall elevation in the
background turbidity and Depth-averaged SS levels in nearby marine water rather
than related to the marine works of the Project.
Given this information, the
overall changes in turbidity and suspended solids levels during the post-project
reporting period in all designated stations including control stations compared
to baseline are likely to represent a natural phenomenon rather than due to the
marine works of the Project. It is
considered that all these measurements were due to natural variations.
This Post Project Monitoring Report presents the EM&A work
undertaken during the period from 4 February 2013 to 20 February 2013 in
accordance with the EM&A Manual
and the requirements under Environmental Permit (EP- 433/2011).
DO levels, turbidity and
suspended solids in Zone A, Zone B and Zone C conducted
within one month of the completion of the Project was found to be generally elevated
compared to that before the commencement of Project works (i.e. baseline data). After detailed analysis and comparison
between the impaction stations and control stations, such overall variations in
all sampling stations are considered to have been driven by natural
fluctuations.
It is concluded that no
deterioration of water quality was observed and hence the effect of the Project
works on water quality at the Project site is considered to be negligible.
([1]) Hong
Kong Observatory (2013) http://www.hko.gov.hk/tide/eQUBtide.htm
[Accessed in February 2013]