Contents
Executive Summary
1 introduction
1.1 Purpose of the
Report
1.2 Structure of the
Report
2 Project Information
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 and Frequency
3.3 Monitoring
Equipment and Methodology
4 IMPLEMENTATION STATUS OF ENVIRONMENTAL
MITIGATION measures
5 Post-Project Monitoring Results
5.1 Deep Water Bay
Area
5.2 Po Toi Area
6 Conclusions
LIST
OF TABLES
Table
2.1 Summary of Environmental Licensing,
Notification, Permit and Reporting Status
Table.3.1 Co-ordinates of Starting Points and Ending
Points for Zones A to E (HK Grid)
Table 3.2 Co-ordinates of All Monitoring Stations in
Deep Water Bay area (Zones A and E) (HK Grid)
Table 3.3 Co-ordinates of All Monitoring Stations in
Po Toi area (Zones B to D) (HK Grid)
Table 3.4 Monitoring Frequency and Parameters for
Post Project Monitoring
LIST
OF ANNEXES
|
Annex
A |
|
|
Annex
B |
|
|
Annex
C |
Impact
Water Quality Monitoring Results – Deep Water Bay Area |
|
Annex
D |
|
|
Annex
E |
Seasonal
Variation of Turbidity and Suspended Solids Levels 1998-2007 |
The cable installation works for
the VSNL Intra Asia Submarine Cable System –
Water
Quality
Six monitoring events were originally
scheduled between 21 and 28 September 2009 but
due to bad weather at Po Toi the schedule was updated
and monitoring events at all designated monitoring
stations were conducted at Deep Water Bay (Zones A and E) on 21, 23 and 25
September and at Po Toi (Zones B to D) on 22, 26
September and 5 October 2009.
In general, the dissolved oxygen levels
recorded during the reporting week were mostly comparable to the results
obtained during the baseline monitoring period. In general, turbidity and suspended
solid levels show seasonal variation, with levels in September/October being
higher than those in February/March (when baseline monitoring was carried
out). Hence turbidity and suspended
solids levels recorded during the reporting period were, in general, slightly
higher than those obtained during the baseline monitoring period.
Conclusion
The overall water quality at
ERM-Hong Kong, Limited (ERM) was appointed by Tata
Communications (Bermuda) Ltd (formerly Videsh Sanchar Nigam Limited (VSNL)) as the Monitoring Team (MT) to implement the
Environmental Monitoring and Audit (EM&A) programme for the VSNL Intra Asia
Submarine Cable System –
This is the Post-Project
EM&A Report, which summarises the post-Project Monitoring results and
audit findings for the EM&A programme during the reporting period from 21
September to 5 October 2009. The
post-Project monitoring results are used to compare with the Baseline and
Impact monitoring results in order to investigate the impact of the project
works on the water quality in the vicinity of the project sites at Deep Water
Bay (Zones A and E) and Po Toi (Zones B to D).
The structure of the report is as follows:
Section
1 : Introduction
Details the background, purpose and structure of the report.
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
locations, parameters and frequency and monitoring equipment and methodologies.
Section
4 : Implementation Status on 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
A) The Deep Water Bay area (Zones A and E) and B) The Po Toi
area (Zones B to D).
Section
6 : Conclusions
Presents the key findings of the post Project monitoring results.
Tata Communications (Bermuda) Ltd (formerly Videsh Sanchar Nigam Limited (VSNL)) has installed a submarine
telecommunications cable, which runs from
In August 2007, a Project
Profile (PP) including an assessment of the potential environmental impacts
associated with the installation of the submarine cable circuit 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 application for Permission
to apply directly for an Environmental Permit (EP). The Environmental Protection Department,
subsequently issued an Environmental Permit (EP-294/2007) and Further
Environmental Permit (FEP-01/294/2007).
Amendments to the permitting requirements were incorporated into the
Environmental Permit to address potential environmental impacts associated with
cable crossings over the HKE’s gas pipeline in
southeast
Baseline Monitoring was conducted near
Impact Monitoring was carried out at
A cable fault
was then identified in the previously laid submarine
telecommunications cable in Zone A.
Hence, the marine works of this Project were resumed on 24 July 2009 to
locate the cable fault and replace the cable. Cable repair works were completed in
Zone A on 11 August 2009 and the cable repair barge “Challenger 1” demobilised
on 12 August 2009.
On
28 August, Post Lay Inspection and Burial (PLIB) works commenced within Zone A
and these were completed in this Zone on 30 August 2009. Further PLIB works continued in the
areas outside the Monitoring Zones A to E where no water quality monitoring was
required according to the EM&A
Manual.
The Contractor confirmed that the marine
works of the Project were completed on the 14 September 2009. Hence, the Post-project Monitoring was
carried out at the
The cable installation runs from
2.3
Status of
Environmental Approval Documents
A summary of the relevant permits,
licences, notifications and/or reports on environmental protection 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-294/2007) |
Throughout the construction period |
Granted on 23 November 2008 |
|
Further Environmental Permit |
(FEP-01/294/2007) |
Throughout the construction period |
Granted on 9 July 2008 |
|
EM&A Manual |
- |
Throughout the construction period |
Approved by EPD on 12 March 2009 |
|
Baseline Water Quality Monitoring Report (Part A) |
- |
Throughout the construction period for Zones A and
E |
Approved by EPD on 1 April 2009 |
|
Baseline Water Quality Monitoring Report (Part B) |
- |
Throughout the construction period for Zones B to D |
Approved by EPD on 30 April 2009 |
|
Pre Installation Geophysical Survey Report |
- |
Throughout the construction period for the Grout
Mattress Installation |
Accepted by AFCD and EPD on 7 July 2009 |
In
accordance with the EM&A Manual,
for post-Project monitoring, water quality sampling was undertaken at stations
situated around the cable works at the Deep Water Bay area (Zones A and E) and
Po Toi area (Zones B to D). This meant water quality sampling was
undertaken throughout the reporting period at the following stations:
·
Zone
A: S1 and S2 are situated at the two Seawater Intake Points in
·
Zone
A: S3 is a Sensitive Receiver used to monitor the water quality conditions of the
Coastal Protection Areas at
·
Zone A:
B1 is an Impact Station used to monitor the effect of the construction works on
·
Zone
A: R1 is a Control Station for S1, S2, S3 and B1 at
·
Zone
E: C4 and C5 are Impact Stations used to monitor the effect of cable laying
works on the water
quality conditions for the coral communities found at Round Island
and the southern side of Chung Hom Wan, respectively;
and
·
Zone
E: R4 is Control Station for C4 and C5 in Zone E. It is not expected to be influenced by
the construction works.
Po
Toi area:
·
Zone
B, C and D: C1, C2 and C3 respectively are located approximately 600 m north of
the cable alignment at Po Toi for monitoring the
effect of cable laying works on coral communities in the area;
·
Zone
B, C and D: F1 is used to monitor the effect of the cable installation works on
the
·
Zone
B, C and D: R2 and R3 are Control Stations for C1, C2, C3 and F1 at Po Toi which are not supposed to be influenced by the cable
laying works due to their remoteness to the construction works.
The co-ordinates of Zones A to E are
listed in Table 3.1 and the
co-ordinates of all the above monitoring stations are listed in Table 3.2 for the
Table.3.1 Co-ordinates
of Starting Points and Ending Points for Zones A to E (HK Grid)
|
Zone |
Starting Point |
Ending Point |
||
|
Easting |
Northing |
Easting |
Northing |
|
|
A |
837029.763 |
811601.699 |
836367.572 |
810545.975 |
|
B |
841917.597 |
802680.115 |
844161.823 |
801308.268 |
|
C |
844161.823 |
801308.268 |
845555.155 |
801495.491 |
|
D |
845555.155 |
801495.491 |
846970.152 |
801749.210 |
|
E |
836469.415 |
809294.174 |
837478.871 |
807740.633 |
Table 3.2 Co-ordinates
of All Monitoring Stations in
|
Station |
Nature |
Corresponding Control Station |
Easting |
Northing |
|
S1 |
Seawater
Intakes |
R1 |
836538.669 |
811528.535 |
|
S2 |
Seawater
Intakes |
R1 |
836195.047 |
810956.409 |
|
S3 |
Coastal
Protection Areas |
R1 |
836677.103 |
810666.744 |
|
B1 |
Gazetted
Beach |
R1 |
837241.114 |
811498.400 |
|
C4 |
Coral
Colonies |
R4 |
836863.233 |
808528.950 |
|
C5 |
Coral
Colonies |
R4 |
838197.242 |
808036.724 |
|
R1 |
Control
Station |
- |
835951.109 |
809052.535 |
|
R4 |
Control
Station |
- |
835934.876 |
807347.391 |
Table 3.3 Co-ordinates
of All Monitoring Stations in
|
Station |
Nature |
Corresponding Control Station |
Easting |
Northing |
|
C1 |
Coral
Colonies |
R2,
R3 |
843547.437 |
802009.952 |
|
C2
(a) |
Coral
Colonies |
R2,
R3 |
844816.539 |
801952.827 |
|
C3 |
Coral
Colonies |
R2,
R3 |
846179.825 |
802224.557 |
|
F1
(b) |
Fish
Culture Zone |
R2,
R3 |
843978.070 |
802732.503 |
|
R2 |
Control
Station |
- |
842075.000 |
803375.038 |
|
R3
(c) |
Control
Station |
- |
847656.611 |
803323.108 |
|
Notes:
(a) The
original location of C2 was situated very close to the shore. C2 is therefore moved about 80 m seaward
from the original location due to safety reasons and the new location is
considered representative. (b) The
original location of F1 was situated very close to the shore. F1 is therefore moved about 40 m
seaward from the original location due to safety reasons and the new location
is considered representative. (c)
Due to rough
sea conditions in the area on 26 September 2009, the locations of three
monitoring stations were moved.
C2 was moved 714 m north-west of its original location and C3, 2003 m
due west of its original location.
R3 was moved 2059 m north-west of its original location, close to the
midpoint of Po Toi Island and Sung Kong. These new locations were all
considered representative. |
||||
3.2
Monitoring
Parameters and Frequency
The post-Project water quality monitoring
was conducted in accordance with the requirements stated in the EM&A Manual. These are presented below.
3.2.1
Monitoring Parameters
Parameters
measured in situ were:
·
dissolved oxygen (DO) (% saturation and mg L-1);
·
temperature (°C);
·
turbidity (NTU); and
·
salinity (‰).
The
only parameter measured in the laboratory was:
·
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, tidal state, special phenomena
and work activities undertaken around the monitoring and works area that may
influence the monitoring results.
3.2.2
Monitoring Frequency
Post-Project
water quality monitoring was carried with each area being sampled three times
in total. At the
For
the Deep Water Bay area, the monitoring was undertaken at eight locations (six
impact monitoring stations S1, S2, S3, B1, C1, C2 and two control monitoring stations R1 and
R4), as shown in Figure
2.2.
For
the Po Toi area, the monitoring was undertaken at six
locations (four impact monitoring stations C1, C2, C3, F1 and two control monitoring stations R2 and
R3), as shown in Figure
2.3.
Samples
were taken during mid-flood and mid-ebb tidal state on each sampling occasion. The
projected monitoring frequency and parameters for Impact Monitoring are
summarised in Table 3.4.
Table
3.4 Monitoring
Frequency and Parameters for Post Project Monitoring
|
Zone |
Station Type |
Monitoring Station |
Post Project Monitoring |
Monitoring Parameters |
|
A |
Control |
R1 |
Po Toi area: 3
days over two weeks ; mid ebb and mid flood tides |
Temperature, Turbidity, Salinity, DO, SS
|
|
Impact |
S1, S2, S3 and B1 |
|||
|
B |
Control |
R2 and R3 |
||
|
Impact |
C1, F1 |
|||
|
C |
Control |
R2 and R3 |
||
|
Impact |
C2, F1 |
|||
|
D |
Control |
R2 and R3 |
||
|
Impact |
C3, F1 |
|||
|
E |
Control |
C4 and C5 |
||
|
Impact |
R4 |
3.3
Monitoring Equipment and
Methodology
3.3.1
Monitoring Equipment
Dissolved Oxygen, Temperature, Salinity,
Turbidity Measuring Equipment
The instrument was a portable, weatherproof
multi-parameter measuring instrument (YSI 6820) complete with cables,
multi-probe sensor, comprehensive operation manuals, and was operable from a DC
power source. It was capable of
measuring:
·
dissolved oxygen levels in the range of 0 –
50 mg L-1; and 0-500% saturation;
·
temperature of -5 to 50 °C;
·
turbidity levels between 0-1000 NTU (response
of the sensor was checked with certified standard turbidity solutions before
the start of measurement); and,
·
salinity in the range of 0-40 ppt (checked with 30 ppt Salinity
solutions before the start of the measurement).
Water Depth Gauge
The water depth gauge affixed to the bottom
of the water quality monitoring vessel was used.
Current Velocity and Direction
Current velocity and direction was estimated
by conducting float tracking.
Positioning Device
A Global Positioning System (GPS) was used
(C-Navigator World DGPS, GPS 72A) during monitoring to ensure the accurate
recording of the position of the monitoring vessel before taking
measurements. The use of DGPS was
used for positioning device, which was well calibrated at an appropriate
checkpoint.
Water Sampling Equipment
Water samples for suspended solids
measurement were collected by the use of a multi-bottle water sampling system
(General Oceanics Inc., Rosette Sampler ROS02),
consisting of PVC bottles of more than two litres,
which could be effectively sealed with cups at both ends. The water sampler had a positive
latching system to keep it open and prevent premature closure until released by
a messenger when the sampler was at the selected water depth.
3.3.2
Monitoring Methodology
Timing & Frequency
The water quality sampling was undertaken
within a 3 hour window of 1.5 hours before and 1.5 hours after mid-flood and mid-ebb
tides. Tidal range for flood and
ebb tides was not less than 0.5 m for capturing representative tides.
Reference was made to the predicted tides at Waglan Island, which is the tidal station nearest to the
Project sites, published on the website of Hong Kong Observatory([1]). Based on the predicted water levels at
Duplicate samples were collected from each of
the monitoring events for in situ measurements and laboratory analysis.
Depths
Each station was sampled and measurements
were taken at three depths, 1 m below the sea surface, mid depth and 1m above
the sea bed. For stations that were
less than 3 m in depth, only the mid depth sample was taken.
Protocols
The multi-parameter measuring instrument (YSI
6820) was checked and calibrated by an HOKLAS accredited laboratory before
use. Onsite calibration was also
carried out to check the responses of sensors and electrodes using certified
standard solutions before each use.
Sufficient stocks of spare parts were maintained for replacements when
necessary, and backup monitoring equipment was made available.
Water samples for SS measurements were
collected in high density polythene bottles, packed in ice (cooled to 4° C
without being frozen), and delivered to an HOKLAS accredited laboratory as soon
as possible after collection.
Laboratory Analysis
All
laboratory work was carried out by 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 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 (for
details refer to Annex B).
Mitigation
measures for water quality control were recommended in the Project Profile and
Environmental Permit. The
Contractor implemented the following measures during cable installation:
·
Marine works within 200 m of the nearest
boundary of the
·
The submarine cable laying works carried out
by diver(s) for the initial segment that extends for about 300m seaward from
the low water mark of the
·
The forward speed of the installation barge
was limited to a maximum of 1 km per hour.
·
A water quality monitoring programme was conducted to ensure no impacts will occur at
the
For
the post-Project monitoring, three monitoring events were scheduled in the
The post-Project monitoring data are
presented in Annex C and compared
with baseline and impact monitoring results in Figures C1-C4.
The
levels of dissolved oxygen measured during the reporting week were mostly
comparable to those obtained during the baseline and impact monitoring
periods. In general, a decreasing
trend in dissolved oxygen levels was detected at all the impact and control
stations during the period from May 2009 to September 2009 but the DO levels
recorded at all the impact stations were of similar magnitude to those measured
at the control stations. The Weekly Impact Monitoring Reports discuss
the seasonal variation or natural fluctuation that may account for the
declining DO trends.
In
general levels of turbidity measured during the reporting week were mostly
comparable to those obtained during the baseline and impact monitoring
periods. The exception was during
the mid-flood measurement taken on 21 September, when three stations (R1, R4,
C5) showed elevated levels of turbidity.
Since two of these stations (R1 and R4) are control stations, situated
at a distance not likely to be affected by the Project works, it is considered
that all these measurements were due to natural variations.
Levels
of suspended solids measured during the reporting week were in general
comparable to those recorded during the baseline monitoring period with some
exceptions. Some measurements taken
at station R1 both during mid-ebb and mid-flow were slightly elevated during
the reporting period, but since this is a control station these measurements
were not considered to be due to Project works. Measurements at R4 and C5 taken during the
mid-ebb tide on 21 September, was also slightly elevated. R4 is a control station and the
measurement taken at C5 was below that of both control stations R4 and R1, so
the measurements were not considered to be due to the Project works. Also on the following two days of
reporting, the measurements at both R4 and C5 were back to levels comparable to
baseline levels once more.
5.2
For
the post-Project monitoring, three monitoring events were scheduled in the Po Toi area between 22 September and 28 September
2009. Due to bad weather in the area,
monitoring was re-scheduled and monitoring events were performed on 22 and 26
September and 5 October 2009.
The
post-Project monitoring data are presented in Annex D and compared with baseline and impact monitoring results in
Figures D1-D4.
The
levels of dissolved oxygen measured during the reporting week were mostly
slightly lower to those obtained during the baseline and impact monitoring
periods. In general, a decreasing
trend in dissolved oxygen levels was detected at all the impact and control
stations during the period from May 2009 to September 2009 but the DO levels
recorded at all the impact stations were of similar magnitude to those measured
at the control stations. The Weekly Impact Monitoring Reports discuss
the seasonal variation or natural fluctuation that may account for the
declining DO trends.
On
average, levels of turbidity and suspended solids measured during the reporting
week were slightly elevated compared to those obtained during the baseline and
impact monitoring periods. The
Environmental Protection Department of the Hong Kong Special Administrative
Region Government (EPD) collects water quality data regularly from various
fixed stations around
Given
this information, the slight increases in turbidity and suspended solids levels
during the reporting period, compared to baseline and impact periods, are
likely to be due to natural variation.
It is also unlikely that the increases were due to Project works, since
the last Project works (cable installation) carried out in the Po Toi area occurred in June 2009, three months
previously. It is therefore
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 21 September to 5 October 2009 in accordance with the EM&A Manual and the requirements under FEP-01/294/2007.
The overall water quality in Zones A to E after the
completion of the Project was found to be similar to that before the
commencement of Project works, taking into account seasonal variations.
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.