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 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 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
Figure
2.1 The
Route of the Proposed Cable System
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
The
barge “Challenger II” was mobilized and anchored in Deep Water Bay where marine
works commenced on 24 July 2009 to locate the cable fault. Construction works included de-burial of
the cable using water jetting inside an enclosed silt curtain and cable repair
operations.
Water
Quality
Prior
to the commencement of the cable recovery and repair works, an ad-hoc water
quality monitoring survey was conducted on 23 July 2009. The monitoring results provided
reference information on the water quality conditions in Deep Water Bay before
the resumption of the marine works.
For
the impact monitoring, six monitoring events were scheduled between 24 July and 30 July 2009. All monitoring events at all designated
monitoring stations were performed on schedule, ie on
24 July, 25 July, 27 July, 28 July, 29 July, and 30 July 2009.
Environmental
Non-conformance
Daily
exceedances of Action and Limit Levels for dissolved
oxygen were recorded during the reporting period. Depth-averaged turbidity was overall compliant with the Action and Limit
Levels. Depth-averaged suspended
solids exceeded both Action and Limit Levels on three days (25 July, 27 July
and 29 July) and exceeded just Action Level on a further two days (28 July and
30 July). Results of detailed
investigations into these exceedances indicated that
none of them were attributed to the Project construction works.
No
complaints were received during the
reporting week.
No environmental summons/prosecution were received
during the reporting week.
Future Key Issues
During
the following week, the repair of the cable will continue including jetting
works and installation of articulated pipes.
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 sixth Weekly Impact Monitoring
Report, which summarises the
impact monitoring results and audit findings for the EM&A programme during
the reporting period from 24 July to 30 July 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 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.
Tata
Communications (Bermuda) Ltd (formerly Videsh Sanchar Nigam Limited (VSNL)) proposes to install a submarine
telecommunications cable, which will run 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 has recently been identified in the
previously laid submarine telecommunications cable in Zone
A. Hence, the marine works of this
Project have been resumed on 24 July 2009 to locate the cable fault and replace
the cable. This report presents
results of the data from monitoring stations in Zone A during cable repair
works. 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 repair barge “Challenger II” was
mobilized on 24 July 2009 to undertake cable fault location and repair
works. A summary of the
major works undertaken during the reporting period is shown in Table 2.1.
Table 2.1 Summary
of Marine Works Undertaken During the Reporting Week
|
Date |
Works Area |
Activity |
|
23 July 2009 |
- |
Mobilisation of cable repair barge “Challenger II” |
|
24 July 2009 |
Zone A |
Anchoring of barge “Challenger II” in Deep Water
Bay. Commencement of operations
to locate cable fault. |
|
25 July 2009 |
Zone A |
Continuation of operations to locate cable fault
including de-burial of cable using water jetting inside a cage-type silt
curtain. |
|
27 July2009 |
Zones A |
Work temporarily suspended due to thunderstorm
warnings. Continuation of
de-burial process for cable exposure and fault location |
|
28 July 2009 |
Zones A |
Continuation of de-burial process for cable
exposure and fault location.
Section of cable found with some damage. |
|
29 July 2009 |
Zone A |
Continuation of de-burial process for cable
exposure. Cable cut near suspected
fault and testing of cable commenced. |
|
30 July 2009 |
Zone A |
Continuation of de-burial process for cable
exposure and recovery. Fault
testing. |
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 |
|
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 is
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 when the cable repair works were undertaken within 500 m (Zone A) of
monitoring stations S1, S2, S3 and B1, which was throughout the reporting
period. .
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 3.3Table
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. |
Prior to the commencement of the cable recovery
and repair works, an ad-hoc water quality monitoring survey was conducted on 23
July 2009. The monitoring results
provided reference information on the water quality conditions in Deep Water
Bay before the resumption of the marine works.
For the impact monitoring, six monitoring
events were scheduled between 24 July and 30 July 2009.
All monitoring events at all designated monitoring stations were
performed on schedule, ie on 24 July, 25 July, 27
July, 28 July, 29 July, and 30 July 2009.
4.1
Data Collected During Mid-Ebb and/or Mid-Flood Tidal
Conditions
In addition to the ad-hoc sampling survey, daily monitoring
events were scheduled between 24 July and 30 July 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 |
|
23
July 2009 |
DO
(Bottom) |
S1,
S2, S3 |
n/a |
|
|
DO
(Depth-averaged) |
None |
n/a |
|
|
Turbidity
(Depth-averaged) |
None |
n/a |
|
|
SS
(Depth-averaged) |
S2,
B1 |
n/a |
|
24
July 2009 |
DO
(Bottom) |
S1,
S2, S3 |
S1,
S2, S3 |
|
|
DO
(Depth-averaged) |
None |
None |
|
|
Turbidity
(Depth-averaged) |
None |
None |
|
|
SS
(Depth-averaged) |
None |
None |
|
25
July 2009 |
DO
(Bottom) |
S1,
S2, S3 |
S1,
S3, B1 |
|
|
DO
(Depth-averaged) |
None |
S3 |
|
|
Turbidity
(Depth-averaged) |
None |
None |
|
|
SS
(Depth-averaged) |
B1 |
S3 |
|
27
July 2009 |
DO
(Bottom) |
S1,
S2, S3 |
S1,
S2, S3, B1 |
|
|
DO
(Depth-averaged) |
None |
None |
|
|
Turbidity
(Depth-averaged) |
None |
None |
|
|
SS
(Depth-averaged) |
B1* |
S1,
B1 |
|
28
July 2009 |
DO
(Bottom) |
S1,
S2, S3 |
S1,
S2 |
|
|
DO
(Depth-averaged) |
None |
None |
|
|
Turbidity
(Depth-averaged) |
None |
None |
|
|
SS
(Depth-averaged) |
S1*,
S2* |
None |
|
29
July 2009 |
DO
(Bottom) |
S1,
S2, S3 |
S1,
S2, S3 |
|
|
DO
(Depth-averaged) |
None |
None |
|
|
Turbidity
(Depth-averaged) |
None |
None |
|
|
SS
(Depth-averaged) |
B1 |
None |
|
30
July 2009 |
DO
(Bottom) |
n/a |
S1,
S2, S3 |
|
|
DO
(Depth-averaged) |
n/a |
None |
|
|
Turbidity
(Depth-averaged) |
n/a |
None |
|
|
SS
(Depth-averaged) |
n/a |
B1* |
* Action Level but not Limit Level exceedance
4.1.1
Exceedances
for Dissolved Oxygen from 24 July to 30 July 2009
Exceedances of the Action and Limit Levels for
Dissolved Oxygen (DO) were recorded daily throughout the reporting period for
bottom DO (DOB) but on only one day for depth averaged DO (24 July 2009) (Table
4.1).
It was observed that the DO trend fluctuates
widely. Similar to the results of
the previous months, DOB concentrations at all the monitoring stations appeared
to be lower than the baseline data.
It should be noted that the DO levels recorded at all the impact
stations were comparable to or higher than the DO measured at the control
station R1. This implies the
background levels of DO were also relatively low. Therefore, 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.
It was concluded in the previous weekly
reports that the recent declining trends of dissolved oxygen and daily DO exceedances could be due to seasonal variation such as
stratification occurred during the summer.
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.
Besides, warmer water temperatures during the summer 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. This phenomenon is
supported by the fact that daily DOB exceedances were
noted whilst relatively high DO concentrations were measured at the surface and
mid-depth from 23 July to 30 July 2009.
It is important that although exceedances of the Action and Limit Levels for DO occurred,
no-non-compliances of the Water Quality Objectives (ie
not less than 2mg/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.
A review of the monitoring data and works
practices concluded that all DO exceedances are
unlikely to be caused by the Project due to the following:
·
Exceedances of the Action and Limit level for DO were
recorded when there were no marine construction activities (ie
23 July 2009 and the morning of 27 July 2009).
·
The
marine works undertaken so far were diver hand jetting operations inside an
enclosed silt curtain and hence these construction activities were not expected
to cause decreases in the DO levels.
·
Continuous
in-situ measurements were taken daily at the impact monitoring stations, ie B1, S1, S2 and S3, at 30- to 60- minute intervals. The DO levels were found to be lower in
the morning but higher in the evening (Figure 4.1) which implies that DO concentrations increased
throughout the day even when the marine works took place. This is because dissolved oxygen
increases during daylight hours when photosynthesis is occurring whilst DO is
being consumed at night when respiration continues but photosynthesis does
not.
·
Relatively
low DO concentrations were recorded at control station R1 at the same tide of
the same day when DO exceedances occurred. This implies the exceedances
may be as a result of the low background level of bottom DO.
In view of the above, the DO exceedances were considered unlikely to be related to the
Project works.
Figure
4.1 Continuous
Measurements of Dissolved Oxygen of Water Samples Collected at the Impact
Monitoring Stations in Zone A
|
|
4.1.2
Exceedances
for Depth-averaged Suspended Solids from 23 July to 30 July 2009
Exceedances of the Action and Limit Levels for
Depth-averaged Suspended Solids (SS) were recorded on four days (23 July, 25
July, 27 July and 29 July) and exceedances of Action
Levels but not Limit Levels on a further two days (28 July and 30 July) (Table
4.1).
A review of the monitoring data and work
practices concluded that all SS exceedances are
unlikely to be caused by the Project due to the following:
·
Some exceedances of the Action and Limit level for SS were
recorded when there were no marine construction activities (23 July 2009 and
the morning of 27 July 2009).
·
Although
SS were 0.3 mg/L above 120% of the Control Station’s SS on 25 July 2009, the
marine works had been suspended for lunch break during water sampling at Station
B1 and no jetting operations were being undertaken.
·
Where
exceedances were above the Action and/or Limit Level
derived from baseline data for SS, all, with the exception of the exceedance at Station B1 on 25 July 2009, were below 120%
of the Control Station SS.
·
All
jetting works were carried out by a diver inside the cage-type silt-curtain.
·
On 28
July, 29 July and 30 July the SS exceedance occurred
at (a) sampling Station(s) upstream of the marine cable works, while at
sampling Stations downstream of the marine cable works, no exceedances
were recorded.
It was, therefore, considered that the SS exceedances were more likely to be caused by localised
factors or temporary tidal influence rather than the Project works.
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 (23 July to 30 July) with the exception of some fluctuations in
the concentrations of bottom DO.
5.1
Summary of
Environmental Exceedance
Daily Notification of Exceedances
(NOEs) with detailed investigation reports were
issued to EPD and AFCD during the monitoring period (ie
24 July to 30 July 2009) for recording water quality monitoring exceedances on dissolved oxygen and 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.
6.1
Key Issues For
The Coming Week
During the following week, the repair of the
cable will continue including jetting works and installation of articulated
pipes.
6.2
Monitoring Schedule For The Coming WEEK
The tentative schedule of water quality
monitoring for the coming week (ie 31 July to 6 August
2009) is presented in Annex A. The water sampling will be conducted at
the same monitoring locations as in this reporting period. However, the tentative schedule of the
water quality monitoring is subject to continued operational progress and
weather constraints.
This Weekly Impact Monitoring Report
presents the EM&A work undertaken during the period from 24 July to 30 July
2009 in accordance with the EM&A Manual and the requirements under FEP-01/294/2007.
Daily exceedances
of Action and Limit Levels for dissolved oxygen and depth-averaged suspended
solids were recorded during the reporting week with the exception of 24 July
2009. Depth-averaged turbidity was
completely compliant with Action and Limit levels. However results of detailed
investigations 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.
