Contents
Executive Summary
1.1 Purpose of the Report
1.2 Structure of the Report
2.1 Background
2.2 Marine Construction Works Undertaken During Reporting Week
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
4.1 Data Collected During Mid-Ebb and/or Mid-Flood Tidal Conditions
4.2 Continuous In-Situ Measurement Data
5 Environmental
Non-CONFORMANCES
5.1 Summary of Environmental Exceedance
5.2 Summary of Environmental Complaint
5.3 Summary of Environmental Summons and Prosecution
6.1 Key Issues For The Coming Week
6.2 Monitoring Schedule For The Coming Week
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 Zone A (HK Grid)
Table 3.2 Co-ordinates of All Monitoring Stations in
Zone A (HK Grid)
Table 3.3 Monitoring Frequency and Parameters for
Impact Monitoring
Table 3.4 Action and Limit Levels of Water Quality
for Zone A
Table 3.5 Event Action Plan for Water Quality
Table 4.1 Summary of Exceedances occurring during
the Reporting Week
LIST
OF ANNEXES
|
Annex
A |
|
|
Annex
B |
|
|
Annex
C |
|
|
Annex
D |
The construction works for the VSNL Intra Asia Submarine Cable
System –
Summary of Construction Works undertaken during the Reporting Period
Post
Lay Inspection and Burial (PLIB) works commenced on 28 August 2009 within Zone
A and were completed on 30 August 2009.
Water
Quality
For
the impact monitoring, three monitoring events were scheduled between 28 August and 3 September 2009. Monitoring events at all designated
monitoring stations were performed on schedule, ie three
events took place on 28 August, 29 August and 30 August.
Environmental Non-conformance
There
were daily exceedances of Action and Limit Levels for
dissolved oxygen bottom layer and just one exceedance
of Action Level but not Limit Level for depth-averaged dissolved oxygen. There were no exceedances
of Turbidity or Suspended Solids. Results
of detailed investigations have indicated that none of the exceedances
of dissolved oxygen were attributed to the Project construction works.
No
complaints were received during the reporting week.
No environmental summons/prosecutions were received during the reporting
week.
Future Key Issues
PLIB
works have now been completed in
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 ninth Weekly Impact Monitoring Report, which summarises the impact monitoring results and audit findings for
the EM&A programme during the reporting period from 28 August to 3 September 2009.
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 parameters, monitoring programmes, monitoring methodologies,
monitoring frequency, monitoring locations, Action and Limit Levels, and Event
/ Action Plans.
Section
4 : Impact Monitoring Results
Summarises the monitoring results obtained in the reporting period.
Section
5 : Environmental
Non-conformance
Summarises
any monitoring exceedances, environmental complaints
and environmental summons within the reporting period.
Section
6 : Future
Key Issues
Summarises the
monitoring schedule for the next week.
Section
7 : Conclusions
Presents the key findings of the impact 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) included 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 has been 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 continue in the areas
outside the Monitoring Zones A to E where no water quality monitoring is
required according to the EM&A Manual.
This
report presents results of the data from monitoring stations in Zone A for the PLIB
works undertaken from 28 August to 30 August 2009. Results of the impact monitoring data
have been compared against the results of the Baseline Environmental Monitoring Part A.
2.2
Marine Construction
Works Undertaken During Reporting Week
During the reporting period,
PLIB works commenced on 28 August 2009 in Zone A and were completed on 30 August
2009. Further PLIB works continue
in the areas outside the Monitoring Zones A to E.
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 2.2.
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,
during all marine works relating to the cable, water quality sampling was
undertaken at stations situated around the cable works at
·
S1
and S2, situated at the two Seawater Intake Points in
Deep Water Bay. They are within 500
m west/northwest of the cable alignment at
·
S3, a
Sensitive Receiver used to monitor the water quality condition of the Coastal Protection Areas
at
·
B1,
an Impact Station used to monitor the effect of the construction activities on
·
R1, a
Control Station for S1, S2, S3 and B1 at
The co-ordinates of Zone A and the above monitoring stations are listed in Table.3.1 and Table 3.2, respectively.
Table.3.1 Co-ordinates
of Starting Points and Ending Points for Zone A (HK
Grid)
|
Zone |
Starting Point |
Ending Point |
||
|
Easting |
Northing |
Easting |
Northing |
|
|
A |
837029.763 |
811601.699 |
836367.572 |
810545.975 |
Table 3.2 Co-ordinates
of All Monitoring Stations in Zone A (HK Grid)
|
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 |
|
R1 |
Control Station |
- |
835951.109 |
809052.535 |
3.2
Monitoring Parameters
and Frequency
The impact 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
Impact
Monitoring at S1, S2, S3, B1 and R1 took place while the cable repair works
were undertaken within 500 m (Zone A) of monitoring stations S1, S2, S3 and B1
Impact monitoring was carried out during
the barge operating hours, normally covering both mid-flood and mid-ebb tidal
conditions, until water quality monitoring was not required.
In-situ
and SS data of the control and impact stations within the impact zone were
collected daily during mid-flood and mid-ebb tidal states (Table 3.3), unless the mid-ebb tide and/or the mid-flood tide were
not occurring during the monitoring period. In addition, continuous in-situ measurements were taken at the impact
monitoring stations, ie B1 & S1-3, at 30- to 60-
minute intervals (subject to the weather conditions and travelling time between
stations) within Zone A. The
monitoring frequency and parameters for Impact Monitoring are summarised in Table
3.3.
Table 3.3 Monitoring
Frequency and Parameters for Impact Monitoring
|
Zone |
Station Type |
Monitoring Station |
Monitoring Frequency |
Monitoring Parameter |
|
|
Mid-ebb Tide / Mid-flood Tide |
30- to 60- Minute Interval |
||||
|
A |
Control |
R1 |
Daily when cable installation works undertaken in
Zone A |
Temperature, Turbidity, Salinity, DO, SS |
- |
|
Impact |
S1, S2, S3 and B1 |
Temperature, Turbidity, Salinity, DO |
|||
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
In-situ and SS data were collected daily at both
control and impact stations in Zone A, provided that the monitoring period had covered
the mid-flood tide and/or mid-ebb tide.
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.
Continuous In-situ
measurements were taken at 30- to 60- minute intervals (subject to the weather
conditions and travelling time between stations) for each impact station within
Zone A.
Reference was made to the predicted tides at Waglan Island, which is the tidal station nearest to the
Project site, 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.
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).
3.3.3
Action
and Limit Levels
The
Action and Limit levels for Zone A, which were established based on the results
of Baseline Environmental Monitoring Part
A, are presented in Table 3.4.
Table 3.4 Action
and Limit Levels of Water Quality for Zone A
|
Parameter |
Action
Level |
Limit
Level |
|
Dissolved Oxygen (DO) (1) |
Surface and Mid-depth (2) |
Surface and Mid-depth (2) |
|
|
5%-ile
of baseline data for surface and middle layer = 6.59 mg L-1 |
1%-ile
of baseline data for bottom layer = 6.42 mg L-1 |
|
|
|
|
|
|
Bottom |
Bottom |
|
|
5%-ile
of baseline data for bottom layers = 6.58 mg L-1 |
1%-ile of baseline for bottom layer = 6.42 mg L-1 |
|
|
|
|
|
Depth-averaged Suspended Solids (SS) (3) (4) |
95%-ile of baseline data = 7.91 mg L-1 |
99%-ile of baseline data = 8.96 mg L-1 |
|
|
or 120% of control station's SS at the same tide
of the same day |
or 130% of control
station's SS at the same tide of the same day |
|
|
|
|
|
Depth-averaged Turbidity (Tby)
(3) (4) |
95%-ile of baseline data = 5.17 NTU |
99%-ile of baseline data = 5.72 NTU |
|
|
or 120% of control station's Tby
at the same tide of the same day |
or 130% of control station's Tby
at the same tide of the same day |
|
|
|
|
|
Notes: (1)
For
DO, non-compliance of the water quality limits occurs when monitoring result
is lower than the limits. (2)
The
Action and Limit Levels for DO for Surface & Middle layer were calculated
from the combined pool of baseline surface layer data and baseline middle
layer data. (3)
“Depth-averaged”
is calculated by taking the arithmetic means of reading of all three depths. (4)
For
turbidity and SS, non-compliance of the water quality limits occurs when
monitoring result is higher than the limits. |
||
3.3.4
Event
and Action Plan
The
Event and Action Plan for water quality monitoring which was stipulated in the EM&A Manual is presented in Table
3.5.
Table 3.5 Event
Action Plan for Water Quality
|
Event |
Contractor |
|
Action
Level Exceedance |
Step 1 - repeat sampling event. Step 2 – identify source(s) of impact and confirm whether exceedance was due to the construction works; Step 3 – inform EPD, AFCD and LCSD and confirm notification of the
non-compliance in writing; Step 4 - discuss with cable installation contractor the most appropriate
method of reducing suspended solids during cable installation (e.g. reduce
cable laying speed/volume of water used during installation). Step 5 - repeat measurements after implementation of mitigation for
confirmation of compliance. Step 6 - if non compliance continues - increase measures in Step 4 and repeat
measurements in Step 5. If non
compliance occurs a third time, suspend cable laying operations. |
|
Limit Level Exceedance |
Undertake Steps 1-5 immediately, if further non
compliance continues at the Limit Level, suspend cable laying operations
until an effective solution is identified. |
For
the impact monitoring, three monitoring events were scheduled between 28 August and 30 September 2009.
Monitoring events at all designated monitoring stations were performed
on schedule, ie the three events took place on 28 August,
29 August and 30 August.
4.1
Data Collected During Mid-Ebb and/or Mid-Flood Tidal Conditions
Daily monitoring events were scheduled between 28 August and 30 August 2009 at
Table 4.1 Summary of Exceedances occurring during the Reporting Week
|
|
|
Exceedance of Action and Limit Levels found at the Impact Monitoring Stations
in Zone A: |
|
|
Date |
Parameter |
Mid-Ebb Tide |
Mid-Flood Tide |
|
28
August 2009 |
DO
(Bottom) |
n/a |
S3 |
|
|
|
|
|
|
29
August 2009 |
DO
(Bottom) |
S1,
S2, S3 |
n/a |
|
|
|
|
|
|
30
August 2009 |
DO
(Bottom) |
S1,
S2, S3 |
n/a |
|
DO
(Depth-averaged) |
S1* |
n/a |
|
Note:*
Action Level but not Limit Level exceedance
n/a indicates that no sampling was taken at
that tide (due to it falling outside working hours).
4.1.1
Exceedances for Dissolved Oxygen from 28 August to 30
August 2009
Exceedances of the Action and Limit Levels for Dissolved
Oxygen (DO) were recorded daily throughout the reporting period for bottom DO
(DOB). One exceedance
of the Action Level but not the Limit Level was recorded for depth
averaged DO on 30 August (Table 4.1).
It is
observed that DO trends fluctuate widely. Similar to the results of the previous
months, DOB concentrations at all the monitoring stations appeared to be lower
than the baseline data. Daily exceedances of Action and Limit Levels set from baseline
data for DOB were observed not only at the impact monitoring stations but also
at the control station, R1 and it should be noted that the DOB levels recorded
at all the impact stations were all (with the exception of one that was
comparable) higher than the DOB measured at the control station. Similarly on the day when the depth-averaged
DO exceeded the Action Level at Station S1, the measurement at the impact
station was still higher than that at the control station (6.49 –v- 5.57 mg L-1).
All this implies that the background levels of DO, particularly DOB,
were relatively low.
It has
been concluded in previous weekly reports that the recent declining trends of
dissolved oxygen and daily DO exceedances could be
due to seasonal variation such as stratification occurring during the
summer. Warmer summer water
temperatures speed up the uptake of oxygen through respiration by living
organisms and decomposition of organic matter in the water column and
sediments. As a result, the
replenishment of dissolved oxygen is less than the DO consumption leading to depletion
in dissolved oxygen concentrations during the summer months.
Also,
for DO, critical conditions usually occur within the bottom waters during the
summer months when the water column is stratified, with a warmer surface layer
separated from deeper water by a picnocline, or
density gradient. When the density
gradient within the picnocline is high, transport of
oxygen from the aerated surface waters to the lower waters by mixing is
significantly reduced. Dissolved
oxygen levels could also decrease in the bottom layer because photosynthesis
and contact with the air may be significantly reduced. This phenomenon is supported for the
reporting week by the fact that all DOB concentrations were lower than DO
concentrations measured at the surface and mid-depth from 28 August to 30 August 2009.
It is
important that although exceedances of the Action and
Limit Levels occurred for DOB and an exceedance of
the Action Level for depth-averaged DO occurred, no-non-compliances of the
Water Quality Objectives (ie not less than 2 mg/L for
90% of samples for bottom DO and not less than 4 mg/L for 90% of samples for
depth-averaged DO) were reported.
In
view of the above, the DO exceedances were considered
unlikely to be related to the Project works.
4.1.2
Exceedance for Turbidity and Depth-averaged Suspended Solids
No
exceedances for turbidity or depth-averaged suspended
solids were recorded during the reporting period.
4.2
Continuous In-Situ Measurement Data
Continuous
in-situ measurements were taken at the
impact monitoring stations within the required monitoring zone at 30- to 60-
minute intervals (subject to the weather conditions and travelling time between
stations) and the results and the graphical presentations were included in Annex D.
In
general, the water quality in the vicinity of the Project works was stable and
acceptable throughout each sampling day (28 August to 30 August).
5.1
Summary of
Environmental Exceedance
Some exceedances were recorded during the monitoring
period (ie 28 August to 30 August 2009) for dissolved
oxygen, at the monitoring stations (Table
4.1). These exceedances
were examined and the results incorporated into the current report (Sections
4.1.1). The investigations
indicated that none of the exceedances were attributed
to the Project works.
5.2
Summary of
Environmental Complaint
No complaints were received during the reporting period.
5.3
Summary of
Environmental Summons and Prosecution
No summons or prosecution on environmental matters were received during
the reporting period.
6.1
Key Issues For The
Coming Week
As there will be no cable installation, repair or PLIB works in the
Monitoring Zones A to E in the following weeks, the impact monitoring has been
suspended The post-project
monitoring will be carried out once the contractor confirms that no additional
marine works will be required.
6.2
Monitoring Schedule For The Coming Week
Since no marine works are scheduled to be carried out within the
Monitoring Zones A to E in the coming weeks, no impact monitoring is scheduled
to take place.
This Weekly Impact Monitoring Report presents the EM&A work
undertaken during the period from 28 August to 3 September 2009 in accordance
with the EM&A Manual and the requirements under FEP-01/294/2007.
There were daily exceedances of Action and
Limit Levels for dissolved oxygen bottom layer and just one exceedance
of the Action Level but not the Limit Level for depth-averaged dissolved oxygen. There were no exceedances
of suspended solids or turbidity during the reporting period. Results of detailed investigations
indicate that none of the DO exceedances were due to
the project works.
No complaints and summons/prosecution were received
during the reporting week.
The MT will keep track of the EM&A programme to verify compliance of
environmental requirements and the proper implementation of all necessary
mitigation measures.