1
introduction
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 – Deep
Water Bay
(thereinafter called the (‘Project’)).
1.1
Purpose of the
Report
This is the third Weekly Impact Monitoring
Report, which summarises the
impact monitoring results and audit findings for the EM&A programme during
the reporting period from 15 May to 21 May 2009.
1.2
Structure of the
Report
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 : Monitoring Results
Summarises the monitoring results obtained in the reporting period.
Section
5 : Environmental Non-conformance
Summarises any
monitoring exceedance, 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.
2
Project Information
2.1
Background
Tata
Communications (Bermuda) Ltd (formerly Videsh Sanchar Nigam Limited (VSNL)) proposes to install a submarine
telecommunications cable, which will run from Deep
Water Bay
and through southeast Hong Kong offshore
waters. The cable landing site will
be at the western edge of Deep
Water Bay
beach at an existing cable landing manhole location. From Deep Water Bay, the cable will extend southwards
towards the East Lamma Channel.
Near to Round
Island, the cable will
turn approximately parallel to the East Lamma Channel passing to the south of
Po Toi Island. The cable will then
run eastward close to the boundary of HKSAR waters and then out beyond Hong
Kong territorial waters into the South China Sea. At the southeast offshore waters, it
will be necessary to install a grout mattress to protect the cable where it
crosses Hong Kong Electric Co., Ltd’s (HKE) gas pipeline. A map of the proposed cable route is
presented in Figure 2.1.
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 Hong Kong
waters. Under the requirements of Condition 3 of the EP, an EM&A
programme as set out in the Environmental
Monitoring and Audit Manual (EM&A Manual) is required to be
implemented. In accordance with the
EM&A Manual, impact monitoring of
water quality is required for the Project.
Baseline
Monitoring was conducted near Deep
Water Bay
(ie Zones A and E) between 27 February 2009 and 9 March 2009 and the results
were presented in the Baseline Water
Quality Monitoring Report Part A.
Baseline monitoring for the Po Toi section of works was undertaken from
27 February 2009 to 13 March 2009 and the Baseline
Water Quality Monitoring Report Part B presented the results of
the monitoring data for Zones B to D near Po Toi Island.
Impact
Monitoring has been carried out at Deep
Water Bay
(ie Zone A) since 25 March 2009. This report presents
results of the data from monitoring stations within Zone A during the cable
installation works in the reporting week.
Results of the impact monitoring data will therefore be compared against
the results of the Baseline
Environmental Monitoring Part A.
2.2
Marine
Construction Works Undertaken during Reporting Week
The
cable installation barge “CB Networker” installs the cable in three phases:
·
Phase
I – Locate in-service cables by divers (ie completed);
·
Phase
II – Conduct route clearance and pre-lay trial run of burial tool “Injector”
(completed); and
·
Phase
III – Install cable along the proposed route using the burial tool “Injector”.
A
summary of the major works undertaken during the reporting week is shown in Table 2.1.
Table 2.1 Summary
of Marine Works Undertaken During the Reporting Week
|
Date
|
Works Area
|
Activity
|
|
15 May 2009
|
Outside Zones A to E
|
Weather Downtime
|
|
16 May 2009
|
Outside Zones A to E
|
Route clearance and pre-lay trail run of burial
tool “Injector”
|
|
17 May 2009
|
Outside Zones A to E
|
Route clearance and pre-lay trail run of burial
tool “Injector”
|
|
18 May 2009
|
Outside Zones A to E
|
Mobilisation of the working vessel to Deep Water
Bay
|
|
19May 2009
|
Zone A
(the working vessel entered Zone A at around 14:47
hrs)
|
Mobilisation of the working vessel to Deep Water
Bay. Preparation works including deployment
of marker buoys and setup for jointing operations stock cable to mini shore
end
|
|
20 May 2009
|
Zone A
|
Onboard
activities to join the Pre-laid shore end to the cable on board the barge
|
|
21 May 2009
|
Zone A
|
Onboard
activities to join the Pre-laid shore end to the cable on board the barge
|
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 2.2 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
|
3
Water Quality Monitoring
Requirements
3.1
Monitoring
Locations
In accordance with the EM&A Manual, during the installation
of the cable in Zone A, water quality sampling was undertaken at stations
situated around the cable laying works at Deep Water Bay
(ie Zone A). The locations of the
sampling stations within Zone A are shown in Figure 3.1.
·
S1
and S2 are situated at the two Seawater Intake Points in Deep Water Bay. They are within 500 m west/northwest of
the cable alignment at Deep
Water Bay
for monitoring the effect of cable laying works in the area. The monitoring works started when the
cable installation works were carried out in Zone A;
·
S3 is
a Sensitive Receiver used to monitor the water quality condition of the Coastal Protection Areas
at Middle Island. The monitoring works took place when
the cable installation works were conducted in Zone A;
·
B1 is
an Impact Station used to monitor the effect of the construction activities on Deep Water
Bay Beach
when the cable installation works were undertaken in Zone A; and
·
R1 is
a Control Station for S1, S2, S3 and B1 at Deep Water Bay which is not supposed to be
influenced by the cable laying works due to its remoteness from the
construction works.
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 Baseline Monitoring Stations (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 when the cable installation works were undertaken within 500 m (Zone A)
of monitoring stations S1, S2, S3 and B1.
The sampling works ceased when no cable installation works were
conducted inside Zone A.
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 Zone A were collected daily
during mid-flood and mid-ebb tidal states (Table
3.3). In addition, continuous in-situ measurements were taken at the
impact monitoring stations, ie B1, S1, S2 and S3, 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 at Zone A
|
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 within Zone A if the monitoring period 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 0.5m 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(). Based on the predicted
water levels at Waglan
Island, the impact water
quality monitoring was conducted following the schedule presented in Annex A.
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 Zones A and E, which were established based on the
results of Baseline Environmental
Monitoring Part A, are presented in Tables
3.4.
Table 3.4 Proposed
Action and Limit Levels of Water Quality for Zones A and E
|
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.
|
4
Impact
Monitoring Results
A
total of three monitoring events were scheduled between 15 May and 21 May
2009 at Deep Water Bay
(ie Zone A). All monitoring events at all designated
monitoring stations within Zone A were performed on schedule, ie on 19 May, 20
May and 21 May 2009.
4.1
Data Collected
During Mid-Ebb and Mid-Flood Tidal Conditions
The monitoring data taken during the
mid-ebb and mid-flood tidal conditions for Zone A are presented in Annex C and compared against the
baseline monitoring results in Figures C1
- C4. The impact monitoring
results obtained during this week were mostly comparable to the results
recorded during the baseline monitoring except that relatively high DO
concentrations were measured on 20 and 21 May 2009.
Results of the
monitoring showed that all
measured dissolved oxygen and turbidity levels complied with the Action and
Limit (AL) Levels specified in the EM&A
Manual. Suspended Solids (SS) levels were
generally compliant with the Action and Limit Levels, however,
exceedances were noted at stations B1, S2 and S3 on 20 May 2009. A review of the above exceedance is
discussed in the following section.
4.1.1
Exceedance on 20 May 2009
Exceedances of the Action and Limit Levels
for Suspended Solids (SS) were recorded at Stations B1, S2 and S3 during the
mid-flood tide on 20 May 2009 (Table 4.1).
The Contractor confirmed that the Networker
was on a four point mooring in Zone A throughout the day of 20 May 2009. Onboard activities were undertaken to
join the Pre-laid shore end to the cable on board the barge. Neither the injector nor the thrusters
were in operation.
It should be noted that the levels of
suspended solids at Stations B1, S2 and S3 exceeded the Action and Limit Levels
but were within 120% of the Control Stations R1’s SS level. This indicates the ambient SS levels
were relatively higher. In
addition, SS levels of all impact stations did not show-non-compliance during
the preceding mid-edd tide. The
dissolved oxygen concentrations maintained at high levels whilst turbidity
levels were generally low throughout the day. This suggests the water quality in Deep Water
Bay was stable and
acceptable on 20 May 2009.
It was considered that the exceedances
were more likely due to an increase in the natural input of SS when water
entered into Deep
Water Bay
toward the beach during the flood tide.
No spatial trend could be drawn from the
monitoring results and hence there were no indications of pollution sources
coming from the Project works area.
The exceedances were, therefore, considered unlikely related to the
Project works.
Table 4.1 Exceedances
of Action and Limit Levels for Suspended Solids during Mid-flood Tide on 20 May
2009
|
Exceedance Log No.
|
0096120_20
May 09_SS_F_Station B1
0096120_20
May 09_SS_F_Station S2
0096120_20
May 09_SS_F_Station S3
|
|
Sampling date
|
20
May 2009
|
|
Monitoring station
|
B1,
S2 and S3
|
|
Parameter
|
Depth-averaged
Suspended Solids (mg/L)
|
|
Action Levels
|
Mid-Flood
|
120%
of R1 = 11.4
|
or
7.91 (baseline data)
|
|
Limit Levels
|
Mid-Flood
|
130%
of R1 = 12.4
|
or
8.96 (baseline data)
|
|
Measured Levels at Station B1
|
Mid-Flood
|
9.67
|
(exceeds
Limit Level)
|
|
Measured Levels at Station S2
|
Mid-Flood
|
9.33
|
(exceeds
Limit Level)
|
|
Measured Levels at Station S3
|
Mid-Flood
|
8.17
|
(exceeds Action Level)
|
4.2
Continuous
In-Situ Measurement Data
Continuous in-situ measurements were taken at the impact monitoring stations,
ie B1, S1, S2 and S3, at 30- to 60- minute intervals (subject to the weather
conditions and travelling time between stations) for Zone A and the results and
the graphical presentations were included in Annex D.
In general, the water quality of Zone A
was stable throughout each sampling day (ie 19 May, 20 May or 21 May 2009) with
the exception of some fluctuations in bottom DO during the first two days.
5
Environmental
Non-CONFORMANCES
5.1
Summary of
Environmental Exceedance
Three Notification of Exceedances (NOEs)
with detailed investigation reports were issued to EPD and AFCD during the
reporting period for recording water quality monitoring exceedances on
suspended solids of the monitoring stations. The exceedances were examined against
the Project works. Results of the
detailed investigation indicated that none of the exceedances were attributed
to the Project construction 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
Future
Key Issues
6.1
Key Issues For
The Coming Month
Works to be taken for the coming
monitoring period are summarised in Table
6.1.
Table 6.1 Construction
Works to be Undertaken in the Coming Monitoring Period
|
Zone
|
Works to be taken
|
|
A
|
Onboard
Construction Activities
|
|
A
|
Phase III Cable
Installation
|
|
E
|
Phase III Cable
Installation
|
|
B
|
Phase III Cable
Installation
|
|
C
|
Phase III Cable
Installation
|
|
D
|
Phase III Cable
Installation
|
6.2
Monitoring
Schedule For The Coming Months
The tentative schedule of water quality
monitoring for the coming week (ie 22 May to 28 May 2009) is presented in Annex
B. The water sampling will be
conducted at the same monitoring location as in this reporting week. However, the tentative schedule of the
water quality monitoring is subject to continued operational progress and
weather constraints.
7
Conclusions
This Weekly Impact Monitoring Report
presents the EM&A work undertaken during the period from 15 May to 21 May
2009 in accordance with the EM&A Manual and the requirements under FEP-01/294/2007.
Three exceedances of Action and Limit
Levels were noted on 20 May 2009 in the reporting week. Results of the detailed investigation
indicated that none of the exceedances were attributed to the Project
construction 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.
