Executive Summary
1 introduction
1.1 Purpose of the
Report
1.2 Structure of the
Report
2 Project
Information
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 Impact
Monitoring Results
4.1 Data Collected
During Mid-Ebb and Mid-Flood Tidal Conditions
4.2 Continuous
In-Situ Measurement Data
5 Environmental
Non-CONFORMANCES
5.1 Summary of
Monitoring Exceedance
5.2 Summary of
Environmental Complaint
5.3 Summary of
Environmental Summons and Prosecution
6 Future
Key Issues
6.1 Key Issues For
The Coming Monitoring Period
6.2 Monitoring
Schedule For The Coming Months
7 Conclusions
Table
2.1 Summary of Marine Works Undertaken During
the Reporting Week
Table 2.2 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
(HK Grid)
Table 3.3 Monitoring Frequency and Parameters for
Impact Monitoring
Table 3.4 Action and Limit Levels of Water Quality
for Zones A and E
Table 3.5 Action and Limit Levels of Dissolved
Oxygen and Turbidity for Zones B to D
Table 3.6 Action and Limit Levels of Suspended
Solids for Impact Stations F1, C1, C2, and C3.
Table 4.1 Exceedances of Action and Limit Levels for
Depth-averaged Turbidity and Suspended Solids during Mid-ebb Tide on 8 May 2009
Table 4.2 Exceedances of Action and Limit Levels for
Depth-averaged Turbidity and Suspended Solids during Mid-flood Tide on 9 May
2009
Table 4.3 Exceedances of Action and Limit Levels for
Depth-averaged Turbidity and Suspended Solids during Mid-ebb Tide on 10 May
2009
Table 4.4 Exceedances of Action and Limit Levels for
Dissolved Oxygen and Depth-averaged Suspended Solids during Mid-ebb and
Mid-flood Tides on 12 May 2009
Table 4.5 Exceedances of Action and Limit Levels for
Dissolved Oxygen, Depth-averaged Turbidity and Suspended Solids during Mid-ebb
Tide on 13 May 2009
Table 6.1 Construction Works to be Undertaken in the
Coming Monitoring Period
LIST
OF FiguresANNEXES
Executive Summary
The construction works for
the VSNL Intra Asia Submarine Cable System – Deep Water Bay commenced on 16 March 2009. This is the second Weekly Impact
Monitoring Report presenting the impact water quality monitoring conducted
during the period from 8 May to 14 May 2009 in accordance with the EM&A
Manual.
Summary of Construction Works
undertaken during the Reporting Period
During
the reporting week, route clearance and pre-lay trail run of burial tool
“Injector” were undertaken in Zones A to E over a
period of five days.
Water Quality
Five monitoring events were scheduled between 8 May and 13 May 2009. All monitoring events at all designated
monitoring stations were performed on schedule, ie on
8 May, 9 May, 10 May, 12 May and 13 May 2009.
Environmental Non-conformance
Twenty-four exceedances of
Action and Limit Levels were noted on five monitoring days, ie
8 May, 9 May, 10 May, 12 May and 13 May in the reporting week. Results of the detailed investigation
indicated that all exceedances, except for those
recorded on 9 May and 13 May 2009, were not due to the Project construction
works. Immediate actions were taken
and further mitigation measures are required to be implemented by the
Contractor to avoid or minimise the water quality impacts associated with the
Project works.
There were
two complaints received on 12 May 2009, via EPD (Regional S), regarding oil
deposits sighted in Deep Water Bay on 21 April 2009 and the sediment plume that
may have arisen from cable laying work in Deep Water Bay on 9 May 2009. Investigations were carried out and the
results indicated only the complaint about the sediment plume was related to
the Project works. The Contractor
was recommended to implement additional mitigation measures to rectify the
situation and the corrective actions were being undertaken by the Contractor
during the reporting period.
No environmental summons or prosecution were received during the reporting week.
Future Key Issues
Works to be undertaken in the coming monitoring
period include mobilisation of working vessel to Deep Water
Bay and preparation works for jointing
operations stock cable to mini shore end prior to the Phase III cable
installation works.
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 2nd
Weekly Impact Monitoring Report, which summarises the impact monitoring
results and audit findings for the EM&A programme during the reporting
period from 8 May to 14 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 in Zones A to E during the cable
installation works. Results of the impact monitoring data will therefore be
compared against the results of the Baseline Environmental Monitoring Part A
and Part B.
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”;
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
|
|
8 May 2009
|
Zone A
|
Mobilization of the working vessel to Deep Water
Bay and preparation
works including deployment of marker buoys and setup of burial tool
“Injector”.
|
|
9 May 2009
|
Zone A
|
Route clearance and pre-lay trail run of burial
tool “Injector”.
|
|
10 May 2009
|
Zone E
|
Route clearance and pre-lay trail run of burial
tool “Injector”
|
|
11 May 2009
|
Outside Zones A to E
|
Route clearance and pre-lay trail run of burial
tool “Injector”
|
|
12 May 2009
|
Zone B
|
Route clearance and pre-lay trail run of burial tool
“Injector”
|
|
13 May 2009
|
Zones C and D
|
Route clearance and pre-lay trail run of burial
tool “Injector”
|
|
14 May 2009
|
Outside Zones A to E
|
Route clearance and pre-lay trail run of burial
tool “Injector”
|
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, water quality sampling was undertaken at stations
situated around the cable laying works at Deep
Water Bay
(ie Zone A), Round Island
(ie Zone E) and Po Toi (ie Zones B to D).
The monitoring at those stations is to ensure the construction works of
the Project do not affect the sensitive area nearby (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 water sampling water 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;
·
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;
·
C1,
C2 and C3 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. The
water quality monitoring at C1 would be initiated when the cable installation barge entered Zone B. Similarly, the monitoring works were
carried out at C2 and C3 when the cable installation
barge moved inside Zones C and D, respectively;
·
F1 is
used to monitor the effect of the cable installation works on the Po Toi Fish Culture Zone (FCZ). It is approximately 1,500 m to the north
of the cable alignment, which is not supposed to be influenced by the cable
laying works due to its remoteness to the construction works. The water quality of the Po Toi FCZ was monitored when the cable
installation was undertaken inside Zones B to 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;
·
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. The water quality
monitoring works commenced when the cable
installation barge entered Zone E; and
·
R4 is
Control Station for C4 and C5 in Zone E.
It is not expected to be influenced by the construction works.
The
co-ordinates of each zone 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 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 (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
|
|
|
|
|
|
|
|
C1
|
Coral
Colonies
|
R2,
R3
|
843547.181
|
802010.004
|
|
C2
|
Coral
Colonies
|
R2,
R3
|
844800
|
801840
|
|
C3
|
Coral
Colonies
|
R2,
R3
|
846179.538
|
802224.554
|
|
C4
|
Coral
Colonies
|
R4
|
836863.233
|
808528.950
|
|
C5
|
Coral
Colonies
|
R4
|
838197.242
|
808036.724
|
|
|
|
|
|
|
|
F1
|
Fish Culture Zone
|
R2, R3
|
843920
|
802730
|
|
|
|
|
|
|
|
R1
|
Control Station
|
-
|
835951.109
|
809052.535
|
|
R2
|
Control
Station
|
-
|
842074.745
|
803375.183
|
|
R3
|
Control
Station
|
-
|
846444
|
804982
|
|
R4
|
Control
Station
|
-
|
835934.876
|
807347.391
|
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 at C1, C2, C3, F1, R2
and R3 commenced when the cable installation barge
was within Zones B, C or D near Po Toi (coral
colonies). The monitoring works
were carried out at C1 and F1 when the cable
installation barge moved inside Zone B. The water quality monitoring at C2 and
F1 was initiated once the cable installation barge exited Zone B and entered
Zone C. Likewise, in situ measurements and water samples
were taken at C3 and F1 when the cable installation
was conducted inside Zone D.
The sampling works halted upon the demobilisation of the cable installation barge.
Impact Monitoring at C4, C5 and R4 started
when the cable installation barge entered Zone
E. No monitoring works would be
performed once the cable installation barge
left Zone E.
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 during mid-flood and mid-ebb tidal states (Table 3.3). In
addition, continuous in-situ
measurements were taken at the impact monitoring station(s), ie C1-5, B1, F1 & S1-3, at 30- to 60- minute intervals
(subject to the weather conditions and travelling time between stations) within
the zone subject to monitoring. 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
|
|
B
|
Control
|
R2 and R3
|
Daily when cable installation works undertaken in Zone
B
|
-
|
|
Impact
|
C1, F1
|
Temperature, Turbidity, Salinity, DO
|
|
C
|
Control
|
R2 and R3
|
Daily when cable installation works undertaken in
Zone C
|
-
|
|
Impact
|
C2, F1
|
Temperature, Turbidity, Salinity, DO
|
|
D
|
Control
|
R2 and R3
|
Daily when cable installation works undertaken in
Zone D
|
-
|
|
Impact
|
C3, F1
|
Temperature, Turbidity, Salinity, DO
|
|
E
|
Control
|
R4
|
Daily when cable installation works undertaken in
Zone E
|
-
|
|
Impact
|
C4 and C5
|
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 check point.
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 during mid-flood tide and mid-ebb tide in the zone
which was under monitoring. 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 the zone
subject to monitoring.
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 Table 3.4.
Table 3.4 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.
|
The Action and Limit levels for Zones B to
D, which were established based on the results of Baseline Environmental Monitoring Part B. The Action and Limit Levels of DO and turbidity
are derived from the baseline monitoring data for all impact stations for Zones
B to D (including Stations F1, C1, C2 and C3), and the results are presented in
Table 3.5. Two sets of the Action and Limit levels
of suspended solids were established for two groups of impact monitoring
station(s) in the area, namely F1 to monitor the FCZ and C1, C2 as well as C3
to monitor the coral communities (see Table
3.6).
Table 3.5 Action
and Limit Levels of Dissolved Oxygen and Turbidity for Zones B to D
|
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 = 7.22 mg L-1
|
1%-ile
of baseline data for bottom layer =7.12 mg L-1
|
|
|
|
|
|
|
Bottom
|
Bottom
|
|
|
5%-ile
of baseline data for bottom layers = 7.14 mg L-1
|
1%-ile of baseline for bottom layer = 7.05 mg L-1
|
|
|
|
|
|
Depth-averaged Turbidity (Tby)
(3) (4)
|
95%-ile of baseline data
= 6.49 NTU
|
99%-ile of baseline data
= 8.35 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, non-compliance of the water quality limits occurs when monitoring
result is higher than the limits.
|
Table 3.6 Action
and Limit Levels of Suspended Solids for Impact Stations F1, C1, C2, and C3.
|
Parameter
|
Action
Level
|
Limit
Level
|
|
Depth-averaged Suspended Solids (SS)
|
Station F1
95%-ile of baseline data = 6.89 mg L-1
|
Station F1
99%-ile of baseline data = 7.11 mg L-1
|
|
|
Stations C1, C2 and C3
95%-ile of baseline data = 12.42 mg L-1
|
Stations C1, C2 and C3
99%-ile of baseline data = 14.28 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
|
|
|
|
|
|
Notes:
(1) “Depth-averaged”
is calculated by taking the arithmetic means of reading of all three depths.
(2) 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
3.7.
Table 3.7 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 five monitoring events were scheduled between 8 May and 13 May
2009. All monitoring events at all designated
monitoring stations were performed on schedule, ie on
8 May, 9 May, 10 May, 12 May and 13 March 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 are presented in Annex C and compared against the
baseline monitoring results in Figures C1
– C8. The impact monitoring
results obtained during this week were mostly comparable to the results
recorded during the baseline monitoring with the exception of 9 May and 13 May
2009.
Results of the
monitoring showed that all
measured dissolved oxygen levels complied with the Action and Limit (AL) Levels
specified in the EM&A Manual
with exception of 12 May and 13 May 2009.
Turbidity and Suspended Solids (SS) levels were generally compliant with the Action and Limit Levels,
however, exceedances were noted at some stations, in
particular on 9 May and 13 May 2009.
A review of the above exceedances is discussed
in the following sections.
4.1.1
Exceedance
on 8 May 2009
Exceedances of the Action and Limit Levels for
Depth-averaged Turbidity and Suspended Solids (SS) were recorded at Stations
SR1 and SR3 during the mid-ebb tide on 8 May 2009 (Table 4.1).
The Contractor confirmed that the marine
works undertaken on 8 May 2009 were vessel mobilization to Deep Water Bay and preparation works including
deployment of marker buoys and setup of Injector. These activities are not expected to
cause significant disturbance to the seabed. No jetting operations were carried out
during the whole day.
It should be noted that the turbidity levels
at SR1 and SR3 during the ebb tide did not exceed the Action and Limit Levels
derived from the baseline data and no sharp increase in turbidity levels was
observed during the continuous in situ
measurements at all the impact monitoring stations (Figure D1, Annex D).
In addition, turbidity and SS levels of
all Impact Stations did not show non-compliance during the following mid-flood
tidal conditions. This implies that
there may be temporarily tidal influence at the area and the exceedances may be caused by natural fluctuation. The exceedances
were, therefore, considered unlikely related to the Project works. No action was required.
Table 4.1 Exceedances of Action and Limit Levels for Depth-averaged
Turbidity and Suspended Solids during Mid-ebb Tide on 8 May 2009
|
Exceedance
Log No.
|
0096120_8 May 09_Turb_E_Station SR1
0096120_8 May 09_Turb_E_Station SR3
0096120_8 May 09_SS_E_Station SR1
|
|
Sampling date
|
8
May 2009
|
|
Monitoring station
|
SR1
and SR3
|
|
Parameter
|
Depth-averaged
Turbidity (NTU)
Depth-averaged
Suspended Solids (mg/L)
|
|
Action Levels
|
Mid-Ebb
|
Turbidity
: 120% of R1 = 2.9
SS
: 120% of R1 = 6.0
|
or 5.17 (baseline data)
or 7.91 (baseline data)
|
|
Mid-Flood
|
Turbidity
: 120% of R1 = 2.9
SS
: 120% of R1 = 7.2
|
or 5.17 (baseline data)
or 7.91 (baseline data)
|
|
Limit Levels
|
Mid-Ebb
|
Turbidity
: 130% of R1 = 3.2
SS
: 130% of R1 = 6.5
|
or 5.72 (baseline data)
or 8.96 (baseline data)
|
|
Mid-Flood
|
Turbidity
: 130% of R1 = 3.1
SS
: 130% of R1 = 7.8
|
or 5.72 (baseline data)
or 8.96 (baseline data)
|
|
Measured Levels at Station SR1
|
Mid-Ebb
|
Turbidity
= 3.92
SS
= 9.67
|
(exceeds
Limit Level)
(exceeds
Limit Level)
|
|
Mid-Flood
|
Turbidity
= 2.20
SS
= 5.00
|
|
|
Measured Levels at Station SR3
|
Mid-Ebb
|
Turbidity
= 3.10
|
(exceeds
Action Level)
|
|
Mid-Flood
|
Turbidity
= 1.92
|
|
4.1.2
Exceedance
on 9 May 2009
Exceedances of the Action and Limit Levels for
Depth-averaged Turbidity and Suspended Solids (SS) were recorded at Stations
SR3 and B1 during the mid-flood tide on 9 May 2009 (Table 4.2).
Investigations were conducted and results indicated the turbidity and SS
exceedances were attributable to the Project
works. Immediate measures were put
in place and further actions are required to be taken by the Contractor to
rectify the incident. All of the
details are presented in Annex E.
Table 4.2 Exceedances of Action and Limit Levels for Depth-averaged
Turbidity and Suspended Solids during Mid-flood Tide on 9 May 2009
|
Exceedance
Log No.
|
0096120_9
May 09_Turb_F_Station B1
0096120_9
May 09_Turb_F_Station SR3
0096120_9
May 09_SS_F_Station B1
0096120_9 May 09_SS_F_Station
SR3
|
|
Sampling date
|
9
May 2009
|
|
Monitoring station
|
B1
and SR3
|
|
Parameter
|
Depth-averaged
Turbidity (NTU)
Depth-averaged
Suspended Solids (mg/L)
|
|
Action Levels
|
Mid-Ebb
|
Turbidity
: 120% of R1 = 4.1
SS :
120% of R1 = 10.2
|
or 5.17 (baseline data)
or 7.91 (baseline data)
|
|
Mid-Flood
|
Turbidity
: 120% of R1 = 3.3
SS
: 120% of R1 = 9.0
|
or 5.17 (baseline data)
or 7.91 (baseline data)
|
|
Limit Levels
|
Mid-Ebb
|
Turbidity
: 130% of R1 = 4.4
SS :
130% of R1 = 11.1
|
or 5.72 (baseline data)
or 8.96 (baseline data)
|
|
Mid-Flood
|
Turbidity
: 130% of R1 = 3.5
SS
: 130% of R1 = 9.8
|
or 5.72 (baseline data)
or 8.96 (baseline data)
|
|
Measured Levels at Station SR3
|
Mid-Ebb
|
Turbidity
= 2.57
SS
= 7.0
|
Mid-Ebb
|
|
Mid-Flood
|
Turbidity
= 11.48
SS
= 28.33
|
(exceeds
Limit Level)
(exceeds
Limit Level)
|
|
Measured Levels at Station B1
|
Mid-Ebb
|
Turbidity
= 0.88
SS
= 4.67
|
|
|
Mid-Flood
|
Turbidity
= 3.37
SS
= 8.50
|
(exceeds
Action Level)
(exceeds
Action Level)
|
4.1.3
Exceedance
on 10 May 2009
Exceedances of the Action and Limit Levels for
Depth-averaged Turbidity and Suspended Solids (SS) were recorded at Station C5
during the mid-ebb tide on 10 May 2009 (Table
4.3).
The Contractor confirmed that the marine
works undertaken on 10 May 2009 were route clearance and pre-lay trial run of
burial tool “Injector” in Zone E.
At the time of monitoring, the vessel was moving southward along the
west coast of the Round
Island in close proximity
to Station C4. It is important to
note that Station C4 was situated much closer to the works area (about 0.3 km)
than C5 (approximately 1.5 km) whilst exceedances
were only noted at C5 during the mid-ebb tide. Turbidity level at C5 exceeded 130% of
the Control Station’s turbidity but was below the Action Level derived from the
baseline data. As seen in Figure D3, Annex D, the turbidity levels of water samples collected at
Stations C4 and C5 were generally stable throughout the day. Depth-averaged SS was only 0.07 mg/L
higher than 130% of the Control Station’s SS. Besides, turbidity and SS levels of all
impact stations did not show non-compliance during the following mid-flood
tide. It was considered that the exceedances recorded during mid-ebb tide at Station C5 were
more likely due to localised factors other than the Project works.
Table 4.3 Exceedances of Action and Limit Levels for Depth-averaged
Turbidity and Suspended Solids during Mid-ebb Tide on 10 May 2009
|
Exceedance
Log No.
|
0096120_10
May 09_Turb_E_Station C5
0096120_10
May 09_SS_E_Station C5
|
|
Sampling date
|
10
May 2009
|
|
Monitoring station
|
C5
|
|
Parameter
|
Depth-averaged
Turbidity (NTU)
Depth-averaged
Suspended Solids (mg/L)
|
|
Action Levels
|
Mid-Ebb
|
Turbidity
: 120% of R4 = 3.4
SS
: 120% of R4 = 8.4
|
or 5.17 (baseline data)
or 7.91 (baseline data)
|
|
Mid-Flood
|
Turbidity
: 120% of R4 = 7.5
SS
: 120% of R4 = 18.0
|
or 5.17 (baseline data)
or 7.91 (baseline data)
|
|
Limit Levels
|
Mid-Ebb
|
Turbidity
: 130% of R4 = 3.7
SS
: 130% of R4 = 9.1
|
or 5.72 (baseline data)
or 8.96 (baseline data)
|
|
Mid-Flood
|
Turbidity
: 130% of R4 = 8.1
SS
: 130% of R4 = 19.5
|
or 5.72 (baseline data)
or 8.96 (baseline data)
|
|
Measured Levels at Station C5
|
Mid-Ebb
|
Turbidity
= 5.03
SS
= 9.17
|
(exceeds
Limit Level)
(exceeds
Limit Level)
|
|
Mid-Flood
|
Turbidity
= 1.82
SS
= 5.00
|
|
4.1.4
Exceedance
on 12 May 2009
Exceedances of the Action and Limit Levels for
Dissolved Oxygen (DO) and Depth-averaged Suspended Solids (SS) were recorded at
Stations C1 and F1 during the mid-ebb and mid-flood tides on 12 May 2009 (Table 4.4).
The DO levels recorded on 12 May 2009 were
only 0.02 – 0.38 mg/L lower than the Action Levels. It was noted that the DO of the water
samples taken at the Control Stations R2 and R3 also below the Action Levels
during both the mid-ebb and mid-flood tidal conditions. DO levels at the impact stations were
generally similar to or higher than those measured at the Control Stations R2
and R3. Furthermore, the
concentrations of DO were very stable and maintained at relatively high levels
throughout the day (Figure D4, Annex D). The DO exceedances
could be a result of natural fluctuation in DO levels due to neap tide where
the slow or non-tidal flow of the waters would lead to poor water
exchange. Nevertheless, the DO
concentrations measured on 12 May 2009 were compliant with the Water Quality
Objectives for DO (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).
Anchor was being deployed at a distance
over 1.6 km from the Impact Station C1 during the course of the water sampling
event. It was observed that the
depth-averaged SS measured at C1 exceeded 120% of Control Station R4 by only
0.5 mg/L but was well below the Action Level derived from the baseline
data. However, SS levels of all
impact stations did not show non-compliance during the preceding mid-ebb tide
when jetting operations were taking place. It was hence considered that the SS exceedance was more likely due to the temporary tidal
influence at the area during the flood tide rather than the Project works.
Table 4.4 Exceedances of Action and Limit Levels for Dissolved Oxygen
and Depth-averaged Suspended Solids during Mid-ebb and Mid-flood Tides on 12
May 2009
|
Exceedance
Log No.
|
0096120_12
May 09_DO_E_Station C1
0096120_12
May 09_DOB_E_Station C1
0096120_12
May 09_DO_E_Station F1
0096120_12
May 09_DOB_E_Station F1
0096120_12
May 09_DO_F_Station C1
0096120_12
May 09_DOB_F_Station C1
0096120_12 May
09_SS_F_Station C1
|
|
Sampling date
|
12
May 2009
|
|
Monitoring station
|
C1
and F1
|
|
Parameter
|
Dissolved
Oxygen, Depth-averaged (DO, mg/L)
Dissolved
Oxygen, Bottom (DOB, mg/L)
Depth-averaged
Suspended Solids (mg/L)
|
|
Action Levels
|
Mid-Ebb
|
DO
= 7.22
DOB
= 7.14
SS
: 120% of R2 = 4.6
SS
: 120% of R3 = 6.9
|
or 12.42 (baseline data)
|
|
Mid-Flood
|
DO
= 7.22
DOB
= 7.14
SS
: 120% of R2 = 5.0
SS
: 120% of R3 = 7.0
|
or 12.42 (baseline data)
|
|
Limit Levels
|
Mid-Ebb
|
DO
= 7.12
DOB
= 7.05
SS
: 130% of R2 = 5.0
SS
: 130% of R3 = 7.48
|
or 14.28 (baseline data)
|
|
Mid-Flood
|
DO
= 7.12
DOB
= 7.05
SS
: 130% of R2 = 5.4
SS
: 130% of R3 = 7.58
|
or 14.28 (baseline data)
|
|
Measured Levels at Station C1
|
Mid-Ebb
|
DO
= 7.00
DOB
= 6.76
SS
= 5.17
|
(exceeds
Limit Level)
(exceeds
Limit Level)
|
|
Mid-Flood
|
DO
= 7.20
DOB
= 6.79
SS
= 7.50
|
(exceeds
Action Level)
(exceeds
Limit Level)
(exceeds
Action Level)
|
|
Measured Levels at Station F1
|
Mid-Ebb
|
DO
= 6.90
DOB
= 6.80
SS
= 6.67
|
(exceeds
Limit Level)
(exceeds
Limit Level)
|
|
Mid-Flood
|
DO
= 7.38
DOB
= 7.24
SS
= 3.50
|
|
4.1.5
Exceedance
on 13 May 2009
Exceedances of the Action and Limit Levels for
Dissolved Oxygen (DO), Depth-averaged Turbidity and Suspended Solids (SS) were
recorded at Station C3 during the mid-ebb tide on 13 May 2009 (Table 4.5).
As discussed earlier, slow movement of
waters during neap tide could cause a decrease in dissolved oxygen levels of
the waters in the vicinity of the Project site. The DO levels recorded on 13 May 2009
were about 0.03 – 0.48 mg/L below than the Limit Levels. The DO concentrations of the water
samples taken at the Control Stations R2 and R3 were also lower than the Action
and Limit Levels. Once again, the
DO concentrations were very stable throughout the day (Figure D5, Annex D) and
complied with 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).
Non-compliance of Water Quality Objective
for SS was recorded at Station C3 during the mid-ebb tide. Between KP 14.8 and 15.3 of the cable
route (see Figure 2.1) an area which lies off the southern tip
of Po Toi Island, the Injector Tool had to be raised
significantly due to the unexpected presence of rock below the seabed. Rather than implementing 10 m deep
clearance, as had been the case up until that point, with the Injector tool
fully engaged in the seabed, the Injector had to be gradually raised till only
4.5 m deep at the highest point of the underlying rock. After passing the area of high relief
rock, the Injector was lowered and again fully engaged in the seabed as quickly
as possible. This could be the
reason for the elevated levels of suspended sediments when the Injector
operating close to the rock and moving upward suddenly. Route clearance and pre-lay trial run of
burial tool “Injector” in Zone D were completed in the afternoon and the vessel
left Zone D on the same day.
Additional water quality monitoring was
conducted on 14 May 2009 to check compliance of water quality. The turbidity and SS of the water
samples at all the Impact Station measured on 14 May 2009 were compliant with
the Action and Limit Levels (Annexes
C10-11). This suggests the
water quality impacts arising from the Project works were temporary and
transient.
The Contractor was recommended to provide
additional mitigation measures to reduce the potential risk of SS elevation
from the upcoming cable installation works (ie Phase
III). As now the Contractor is
aware of the locations of the hard substrate below the seabed along the cable
route, there will be no attempt to further lower the Injector during the cable
installation run. The Contractor
will ensure that the jetting water pressure applied is backed off such that
just enough water pressure being applied allows the cable to be installed. This will minimise the quantity of
sediment to be suspended during the operation. The installation run will also be made at
the safe speed possible.
Table 4.5 Exceedances of Action and Limit Levels for Dissolved
Oxygen, Depth-averaged Turbidity and Suspended Solids during Mid-ebb Tide on 13
May 2009
|
Exceedance
Log No.
|
0096120_13
May 09_DO_E_Station C2
0096120_13
May 09_DOB_E_Station C2
0096120_13
May 09_DO_E_Station C3
0096120_13
May 09_DOB_E_Station C3
0096120_13
May 09_DO_E_Station F1
0096120_13
May 09_DOB_E_Station F1
0096120_13
May 09_Turb_E_Station C3
0096120_13
May 09_SS_E_Station C3
|
|
Sampling date
|
13
May 2009
|
|
Monitoring station
|
F1,
C2 and C3
|
|
Parameter
|
Dissolved
Oxygen, Depth-averaged (DO, mg/L)
Dissolved
Oxygen, Bottom (DOB, mg/L)
Depth-averaged
Turbidity (NTU)
Depth-averaged
Suspended Solids (mg/L)
|
|
Action Levels
|
Mid-Ebb
|
DO = 7.22
DOB = 7.14
|
|
|
Turbidity :
120% of R2 = 2.3
Turbidity :
120% of R3 = 2.74
|
or 6.49
(baseline data)
|
|
SS : 120% of R2
= 6.2
SS : 120% of R3
= 10.4
|
or 6.89 (F1 -
baseline data)
or 12.42 (C1,
C2, C3 - baseline data)
|
|
Limit Levels
|
Mid-Ebb
|
DO = 7.12
DOB = 7.02
|
|
|
Turbidity :
120% of R2 = 2.4
Turbidity :
120% of R3 = 2.97
|
or 8.35
(baseline data)
|
|
SS : 130% of R2
= 6.7
SS : 130% of R3
= 11.27
|
or 8.35 (F1 - baseline
data)
or 14.28 (C1,
C2, C3 - baseline data)
|
|
Measured Levels at Station F1
|
Mid-Ebb
|
DO = 7.17
DOB
= 6.96
Turbidity
= 0.65
SS = 4.5
|
(exceeds
Action Level)
(exceeds
Limit Level)
|
|
Measured Levels at Station C2
|
Mid-Ebb
|
DO = 7.15
DOB
= 6.66
Turbidity
= 1.18
SS = 3.0
|
(exceeds
Action Level)
(exceeds
Limit Level)
|
|
Measured Levels at Station C3
|
Mid-Ebb
|
DO = 7.09
DOB
= 6.57
Turbidity
= 12.25
SS = 17.5
|
(exceeds
Limit Level)
(exceeds
Limit Level)
(exceeds
Limit Level)
(exceeds Limit
Level)
|
4.2
Continuous
In-Situ Measurement Data
Continuous in-situ measurements were taken at the impact monitoring stations, ie C1-5, B1, F1 & S1-3, at 30- to 60- minute intervals (subject
to the weather conditions and travelling time between stations) within the zone
subject to monitoring 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 (ie 8 May, 9 May, 10 May, 12 May and 13
May 2009). No sudden drop in
dissolved oxygen concentrations nor sharp increase in turbidity levels was
observed on each monitoring day with the exception of the turbidity measured on
9 May and 13 May 09.
5
Environmental
Non-CONFORMANCES
5.1
Summary of
Monitoring Exceedance
Twenty-four 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 dissolved oxygen, turbidity and suspended solids of the monitoring stations.
The exceedances were examined against the
Project works. Results of the
detailed investigation indicated that all exceedances,
except for those recorded on 9 May and 13 May 2009, were not due to the Project
construction works. A description
of the actions to be taken following these non-compliances is discussed in Section 4.1.
5.2
Summary of
Environmental Complaint
There
were two complaints received on 12 May 2009, via EPD (Regional S), regarding
oil deposits sighted in Deep Water Bay on 21 April 2009 and the sediment plume
that may have arisen from cable laying work in Deep Water Bay on 9 May 2009. Investigation reports were submitted to
EPD on 18 May 2009 and findings of the investigations indicated that only the
complaint about the sediment plume was related to the Project works. Details of the incidents and mitigation
measures implemented by the Contractor are given in Annex E.
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 Monitoring Period
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
|
Setup for jointing
operations stock cable to mini shore end in Deep Water
Bay
|
|
A
|
Joint
construction to mini shore end (onboard 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 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 8 May to 14 May
2009 in accordance with the EM&A Manual and the requirements under FEP-01/294/2007.
Twenty-four exceedances
of Action and Limit Levels were noted on five monitoring days, ie 8 May, 9 May, 10 May, 12 May and 13 May in the reporting
week. Results of the detailed
investigation indicated that all exceedances, except
for those recorded on 9 May and 13 May 2009, were not due to the Project
construction works. Implementation of additional mitigation measures are
required for the Phase III cable installation works.
There
were two complaints received on 12 May 2009, via EPD (Regional S), regarding
oil deposits sighted in Deep Water Bay on 21 April 2009 and the sediment plume
that may have arisen from cable laying work in Deep Water Bay on 9 May
2009. Investigations were carried
out and the results indicated only the complaint about the sediment plume was
related to the Project works.
Remedial actions were being undertaken by the Contractor during the
reporting period to rectify the situation.
No environmental
summons or 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.
