Contents
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 Impact
Water Quality Monitoring Requirements
3.1 Monitoring
Locations
3.2 Monitoring
Parameters
3.3 Monitoring
Equipment and Methodology
4.1 Data
Collected During Reporting Period
4.2 Exceedances
During Reporting Period
5 Environmental
Non-CONFORMANCES
5.1 Summary
of Environmental Exceedance
5.2 Summary
of Environmental Non-compliance
5.3 Summary
of Environmental Complaint
5.4 Summary
of Environmental Summons and Prosecution
6.1 Key
Issues For The Coming Reporting Period
6.2 Monitoring
Schedule For The Coming Reporting Period
LIST
OF TABLES
Table 2.1 Summary of Environmental Licensing, Notification, Permit and
Reporting Status
Table 3.1 Co-ordinates of Water Quality Monitoring Stations in Zone C
Table 3.2 Equipment Used
during the Impact Water Quality Monitoring
Table 3.3 Monitoring Frequency and Parameters for Impact Monitoring in Zone C
Table 3.4 Action and Limit Levels of Water Quality for Zones C
Table 3.5 Event Action Plan for Water Quality
Table 4.1 Summary of Exceedances Occurring during the Reporting Week
Table 4.2 Exceedances of Action and Limit Levels on 15 October 2012
Table 4.3 Exceedances of Action and Limit Levels on 16 October 2012
LIST
OF ANNEXES
Annex A |
|
Annex B |
|
Annex C |
|
|
|
The submarine
cable installation works for the Asia Submarine-cable
Express (ASE) cable system were commenced
on 8 October 2012. This is the Second Weekly Impact Water Quality Monitoring Report presenting the impact water quality monitoring
conducted during the period from 15
October 2012 to 21 October 2012 in accordance with the Monitoring and Audit Manual
(EM&A Manual).
Summary of
Construction Works Undertaken during the Reporting Period
During
the reporting period, submarine cable laying works were conducted in Zone C and
from Zone C eastward to the boundary of Hong Kong marine waters.
Water Quality Monitoring
Two monitoring events were scheduled
in the reporting period in Zone C.
Monitoring events at designated monitoring stations in Zone C were
performed on schedule.
Environmental
Non-conformance
Exceedances
of Action and Limit Levels were recorded during the reporting week. However, the exceedances
were considered to reflect natural background fluctuation rather than impact
caused by the Project.
No complaint
and summons/prosecution was received during the reporting week.
Future
Key Issues
During the
following week, there will be cable installation works from Zone C eastward to
the boundary of Hong Kong marine waters which are outside Zone A, Zone B and
Zone C. Hence, no impact
water quality monitoring will be conducted in the coming week.
ERM-Hong Kong, Limited
(ERM) was appointed by NTT Com Asia (NTTCA) as the Environmental Team (ET) to
implement the Environmental Monitoring and Audit (EM&A) programme for the
installation of a telecommunication cable (Asia-Submarine-cable Express (ASE)) of
approximately 7,200 km in length, connecting Japan and Singapore with branches
to the Philippines, Hong Kong SAR (HKSAR) and Malaysia (thereinafter called the Project).
This is the Second Weekly Impact Water Quality Monitoring Report, which summarises the
results of impact water quality monitoring as part of the EM&A programme
during the reporting period from 15 October 2012 to 21 October 2012.
The
structure of the Report is as follows:
Section
1 : Introduction
Provides details of the background,
purpose and report structure.
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 Plan.
Section
4 : Monitoring
Results
Summarises the water quality
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 reporting period.
Section
7 : Conclusions
Presents the key findings
of the impact monitoring results.
NTT
Com Asia (NTTCA) proposes to install a telecommunication cable (Asia
Submarine-cable Express (ASE) cable) of approximately 7,200 km in length,
connecting Japan and Singapore with branches to the Philippines, Hong Kong SAR
(HKSAR) and Malaysia. NTTCA is
responsible for securing the approval to land the ASE cable in Tseung Kwan O, Hong Kong SAR (HKSAR). The proposed landing site will be at a
new Beach Manhole (BMH) and ultimately connect with a Data Centre in Tseung Kwan O (TKO) Industrial Estate which is scheduled
for completion in 2012. From Tseung Kwan O, the cable will extend eastward approaching
the Tathong Channel. Near to Cape Collinson,
the cable is approximately parallel to the Tathong
Channel until north of Waglan Island where the cable
travels eastward to the boundary of HKSAR waters where it enters the South
China Sea. The total length of
cable in Hong Kong SAR waters is approximately 33.5 km. A map of the proposed cable route is
presented in Figure 2.1.
A
Project Profile (PP-452/2011) which includes an assessment of the potential
environmental impacts associated with the installation of the submarine
telecommunications cable system 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 the
application for Permission to apply directly for Environmental Permit
(EP). The Environmental Protection
Department, subsequently issued an Environmental Permit (EP- 433/2011).
Pursuant
to Condition 2.4 of the EP, an environmental monitoring and audit programme as
set out in the Environmental Monitoring
and Audit Manual (EM&A Manual)
is required to be implemented. In
accordance with Section 2 of the EM&A
Manual, impact monitoring of marine water quality
should be undertaken when the cable installation barge works in Zone A , Zone B
and Zone C.
Impact
monitoring started on
8 October 2012 in parallel
with the submarine cable laying works in Zone A and Zone B. During this reporting week, the impact
monitoring was continually conducted on a daily basis as the cable laying works
proceeded in Zone C and ceased when
the barge moved outside Zone C. This Report therefore
presents the monitoring results from the monitoring stations within Zone C. .
During
the reporting period from 15 October 2012 to 21
October 2012, submarine cable laying
works were conducted in Zone C and from Zone C eastward to the boundary of Hong Kong marine waters.
A
summary of the relevant permits, licences and reports on environmental
protection for this Project is presented in Table
2.1.
Table 2.1 Summary of Environmental
Licensing, Notification, Permit and Reporting Status
Permit /
Licence / Notification / Report |
Reference |
Validity
Period |
Remarks |
Environmental
Permit |
EP
433/2011 |
Throughout
the construction and operation stages |
Granted
on 20 December 2011 |
EM&A
Manual |
- |
Throughout
the construction stage |
Revised
EM&A Manual submitted on 18 September 2012 |
Baseline
Water Quality Monitoring Report (Zone A) |
- |
Throughout
the construction period for Zone A |
Submitted
on 19 September 2012 |
Baseline
Water Quality Monitoring Report (Zone B) |
- |
Throughout
the construction period for Zone B |
Submitted
on 25 September 2012 |
Baseline
Water Quality Monitoring Report (Zone C) |
|
Throughout
the construction period for Zone C |
Submitted on 1 October 2012 |
In accordance with the EM&A Manual, during the installation
of the cable system in Zone C, water quality samplings
were collected at the stations situated around the cable laying works in
Zone C. The
locations of the sampling stations within Zone C are shown in Figure 3.1.
¡P
E4
is the Impact Station to monitor the impacts of cable installation works on the
coral communities at the coast of Sung Kong;
¡P
E5
is the Impact Station to monitor the impacts of cable installation works on the
coral communities at the coast of Waglan Island;
¡P
G5
is the Gradient Station between E4 and the alignment;
¡P
G6
is the Gradient Station between E5 and the alignment; and
¡P
C3
is a Control Station (approximately 3 km from the proposed cable alignment) for
Zone C. It is not supposed to be
influenced by the cable laying works due to its remoteness to the construction
works.
The
co-ordinates of the above monitoring stations in Zone C are listed in Table 3.1.
Table 3.1 Co-ordinates of Water
Quality Monitoring Stations in Zone C
Monitoring
Station |
Nature |
Easting |
Northing |
E4 |
Impact Station (Coral Communities) |
843210 |
816322 |
E5 |
Impact Station (Coral Communities) |
844627 |
813609 |
G5 |
Gradient
Station |
847795 |
806678 |
G6 |
Gradient
Station |
849703 |
806636 |
C3 |
Control
Station |
848556 |
804750 |
The
impact water quality monitoring was conducted in accordance with the
requirements stated in the EM&A
Manual. Monitoring parameters
are presented as below.
Parameters measured in situ were:
¡P
dissolved oxygen (DO) (%
saturation and mg L-1);
¡P
temperature (¢XC);
¡P
turbidity (NTU); and
¡P
salinity (‰).
The only parameter measured
in the laboratory was:
¡P
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, special phenomena and work activities undertaken
around the monitoring and works area that may influence the monitoring results.
Table 3.2 summaries
the equipment used for the impact water quality monitoring.
Table 3.2 Equipment
Used during the Impact Water Quality Monitoring
Equipment |
Model |
Global Positioning Device |
Garmin etrex 10 |
Water Depth Gauge |
Speedtech Instrument SM-5A |
Water Sampling Equipment |
1510 Kemmerer Water
Sampler |
Salinity, DO, Temperature
Measuring Meter |
YSI Pro 2030 |
Current Velocity and
Direction |
Flow Probe FP11 |
Turbidity Meter |
HACH Model 2100Q Turbid
Meter |
In-situ
data and SS data were collected during the cable installation works from 7:00
to 23:00 on a
daily basis. The impact monitoring
schedule for the reporting period is presented in Annex A.
Impact
monitoring at E4, E5, G5, G6 and C3 was commenced
once the
cable installation works started within
Zone C. The monitoring ceased
once the cable installation barge moved outside Zone C or no
cable laying works were being undertaken within Zone C.
Due to the weather
conditions and travelling time between stations, in-situ and SS measurements were taken at the impact monitoring stations
with approximately 2-hour interval in Zone C. The monitoring frequency and parameters
for water quality impact monitoring are summarised in Table 3.3.
Table
3.3 Monitoring
Frequency and Parameters for Impact Monitoring in Zone C
Zone |
Station Type |
Monitoring Station |
Monitoring Frequency |
Monitoring Parameter |
C |
Control |
C3 |
Daily at ~2-hour interval while cable
installation works were being undertaken in Zone C |
Temperature, Turbidity, Salinity, DO and SS |
Gradient |
G5, G6 |
|||
Impact |
E4, E5 |
Duplicate samples were collected from each of the
monitoring events for in situ measurements and laboratory analysis.
Each station was sampled and measurements/ water samples
were taken at three depths, namely, 1 m below water surface, mid-depth and 1 m
above sea bed, except where the water depth less than 6 m, the mid-depth
station may be omitted. For
stations that are less than 3 m in depth, only the mid-depth sample was taken.
For in situ measurements, duplicate readings were
made at each water depth at each station.
Duplicate water samples were collected at each water depth at each
station.
All
in situ monitoring instruments were
checked, calibrated and certified by a laboratory accredited under HOKLAS or
any other international accreditation scheme before use, and subsequently
re-calibrated at-monthly intervals throughout all stages of the water quality
monitoring. Responses of sensors
and electrodes were checked with certified standard solutions before each use.
For
the on-site calibration of field equipment, the BS 1427: 1993, Guide to Field and On-Site Test Methods for the Analysis
of Waters was observed.
Sufficient stocks of spare parts were maintained for replacements when
necessary. Backup monitoring
equipment was made available.
Water
samples for SS measurements were collected in high density polythene bottles,
packed in ice (cooled to 4¢X C without being frozen), and delivered to a HOKLAS
laboratory as soon as possible after collection.
Two
replicate samples were collected from each of the monitoring events for in situ measurement and lab analysis.
All laboratory work was carried
out in 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 SS laboratory measurements were
provided within 2 days of the sampling event (48 hours). 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 (Annex
B)
The Action and Limit levels
for Zones C, which were established
based on the results of Baseline Water
Quality Monitoring Report (Zone C), are presented in Table 3.4.
Table 3.4 Action
and Limit Levels of Water Quality for Zones C
Parameter |
Action Level |
Limit Level |
SS in mgL-1 (Depth-averaged) (a)
(c) |
95%-ile of baseline data (2.44
mg L-1), or |
99%-ile of baseline data (2.48
mg L-1) , and |
20%
exceedance of value at any impact station compared
with corresponding data from control station |
30%
exceedance of value at any impact station compared with
corresponding data from control
station |
|
DO in mgL-1
(b) |
Surface and Middle(d) 5%-ile of baseline data for surface and middle layer (5.62
mg L-1) |
Surface and Middle(d) 5mg/L
or 1%-ile of baseline for surface and middle layer (5.58
mg L-1) |
Bottom 5%-ile of baseline data for bottom layers (5.46 mg L-1) |
Bottom 2mg/L
or 1%-ile of baseline data for bottom layer (5.41 mg L-1) |
|
Turbidity in NTU
(Depth-averaged) (a) (c) |
95%-ile of baseline data (1.44
NTU), or |
99%-ile of baseline data (1.50
NTU), and |
20%
exceedance of value at any impact station compared
with corresponding data from control station |
30%
exceedance of value at any impact station compared
with corresponding data from
control station |
|
Notes: a. ¡§Depth-averaged¡¨
is calculated by taking the arithmetic means of reading of all sampled
depths. b. For DO,
non-compliance of the water quality limits occurs when the monitoring result
is lower than the limits. c. For SS
and turbidity, non-compliance of the water quality limits occurs when
monitoring result is higher than the limits. d. The
Action and Limit Level for DO for surface and middle layer were calculated
from the combined pool of baseline surface layer data and baseline middle
layer data. |
The Event and Action Plan
for water quality monitoring which was stipulated in 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 ¡V identify
source(s) of impact and confirm whether exceedance
was due to the construction works; Step
3 ¡V 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. |
A total of two monitoring events were
scheduled in the reporting period between 15 October
2012 and 21 October 2012 (Annex A). Monitoring events at all designated
monitoring stations within Zone C were performed on schedule. No major activities influencing the
water quality were identified during the reporting period.
Continuous water sampling
was taken at the impact monitoring stations in Zone C at approximately 2-hour intervals on a daily
basis. In general, water quality in
Zone C was stable throughout each
sampling day though natural fluctuation existed. Neither sudden drop in dissolved oxygen
concentrations nor sharp increase in turbidity levels and suspended solid
levels were observed on each monitoring day. The results of the impact monitoring and
their graphical presentations are included in Annex C.
Despite
relatively stable water quality, exceedances of the Action and Limit
Levels were recorded during the reporting week. A summary of stations where exceedances were recorded is presented in Table4.1. Exceedances with
detailed information of location and time were presented in Annex C.
Table 4.1
Summary of Exceedances Occurring during the Reporting Week
Surface
DO |
Middle
DO |
Bottom
DO |
Depth-averaged
Turbidity |
Depth-averaged
SS |
||||||
Date |
Exceedances |
|||||||||
Action Level |
Limit Level |
Action Level |
Limit Level |
Action Level |
Limit Level |
Action Level |
Limit Level |
Action Level |
Limit Level |
|
15/10 |
|
|
|
E5 |
|
|
E4, E5 |
|
E4, E5 |
|
16/10 |
|
|
E4 |
E4 |
E4 |
|
E4, E5 |
|
E4, E5 |
|
Exceedances of the Action Levels in
depth-averaged Turbidity and depth-averaged SS were recorded at Impact Station
E4 and E5 in the 1st, 2nd, 3rd and 4th
sampling rounds on 15 October 2012 (Table
4.2). Exceedance
of the Limit Level in mid-depth DO were also observed at Station E5 in the 8th
sampling round on 15 October 2012 (Table
4.2)
According
to the daily barge operation report, there were some preparation and
maintenance works carried out by the Contractor before burial operation. The burial operation (i.e. jetting
works) was conducted from 10:15 to 18:30 on 15 October 2012, which overlapped
with the marine water quality monitoring.
Jetting works for the Project were not being
undertaken when the exceedances in middle DO,
depth-averaged Turbidity and depth-averaged SS were recorded at E4 and E5 in
the 1st (07:00 ¡V 09:00), 2nd (09:07 ¡V 10:07) and 8th
(21:01 ¡V 22:52) rounds of marine water quality monitoring. Therefore, the exceedances
of the Action and Limit Levels at E4 and E5 are considered to represent natural
background fluctuations.
During
3rd and 4th rounds of water sampling, the mean
depth-averaged Turbidity and mean depth-averaged SS at Impact Station E4 and E5
where exceedances were recorded are similar to the
average levels at Control Station C3 (Turbidity = 1.67 NTU, SS = 2.60 mg/L). Since Control Station C3 is far away (~3
km) from the jetting locations and should not be affected by the Project, the
similar levels between impact stations and the control station would indicate
that the exceedances observed at the Impact Station E4
and E5 were unlikely to be caused by the jetting works but represented natural
background fluctuations during monitoring period.
Table 4.2 Exceedances
of Action and Limit Levels on 15 October
2012
Date |
15
October 2012 (Measured) 17
October 2012 (In situ results
received by ERM) 19
October 2012 (Laboratory results received by ERM) |
||
Monitoring
Station |
E4 and E5 |
||
Parameter(s)
with Exceedance(s) |
Middle DO (mg/L) |
Depth-averaged Turbidity (NTU) |
Depth-averaged SS (mg/L) |
Action
Levels |
5.62 mg/L |
1.44 NTU or 20% exceedance
of data at control station |
2.44 mg/L or 20% exceedance
of data at control station |
Limit
Levels |
5.58 mg/L |
1.50 NTU and 30% exceedance
of data at control station |
2.48 mg/L and 30% exceedance
of data at control station |
Measured
Levels at Impact Stations Where Exceedances Were
Recorded |
1st
Round |
Turbidity: E4=1.52 NTU; E5=1.63 NTU. SS: E4=2.53 mg/L; E5=2.67 mg/L. |
|
2nd
Round |
Turbidity: E4=1.77 NTU; E5=1.69 NTU. SS: E4=2.78 mg/L; E5=2.68 mg/L. |
||
3rd
Round |
Turbidity: E4=1.73 NTU; E5=1.61 NTU. SS: E4=2.75 mg/L; E5=2.60 mg/L. |
||
4th
Round |
Turbidity: E4=1.69 NTU; E5=1.68 NTU. SS: E4=2.72 mg/L; E5=2.67 mg/L. |
||
8th
Round |
Middle DO: E5=5.56 mg/L. |
||
Exceedances |
1st
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
|
2nd
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
||
3rd
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
||
4th
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
||
8th
Round |
Exceedance of Limit Level in Middle DO: E5. |
Exceedances of Action Level in
depth-averaged Turbidity and depth-averaged SS were recorded at StationsE4 and
E5 in all eight sampling rounds on 16 October 2012. Additionally, exceedances
of Action and Limit Levels in middle/bottom DO were recorded at Station E4 in
the 5th, 6th and 8th sampling rounds (Table 4.3).
According
to the daily barge operation report, there were some preparation and
maintenance works carried out by the Contractor before burial operation. It is also noted the bad sea condition
(i.e. strong swell) in the morning which only allows the burial operation (i.e.
jetting works) to have been conducted between 15:20 to 19:20 on 16 October
2012, which overlapped with the marine water quality monitoring.
As
stated above, jetting works for the Project were not being undertaken when the exceedances in depth-averaged Turbidity and depth-averaged
SS were recorded at E4 and E5 in the first four rounds of marine water quality
monitoring (07:00 ¡V 15:01).
Therefore, the exceedances of Action Levels at
E4 and E5 in this period are considered to represent natural background
fluctuations.
During the 5th, 6th,7th
and 8th rounds of water sampling, the mean depth-averaged Turbidity
and mean depth-averaged SS levels at Impact Station (E4 and E5) where exceedances were recorded were lower than the average
levels at Control Station C3 (Turbidity = 1.70 NTU, SS = 2.74 mg/L). Since the control station is far away
(~3 km) from the jetting locations and should not be affected by the Project,
the lower Turbidity and SS levels at impact stations than those at Control
Station C would indicate the exceedances observed at
the Impact Station E4 and E5 were unlikely to be caused by the jetting works
but represent natural background fluctuations during the monitoring period.
During the 5th and 6th
rounds of water sampling, exceedances of Action and
Limit levels in middle DO were recorded at the impact station E4. However in the same sampling rounds, the
middle DO values were recorded to be compliant with the Action Level at both
gradient stations G5 and G6, which are situated between the cable installation
barge and E4 and should be more susceptible to the impact of the Project (if
any). Therefore the exceedances measured at E4 in the 5th and 6th
rounds, as well as in the last round when cable installation works of the
Project were ceased for the day, were unlikely to be caused by the jetting
works but represent natural background fluctuations during monitoring events.
Table
4.3 Exceedances of Action and Limit Levels on 16 October 2012
Date |
16 October 2012 (Measured) 17 October 2012 (In situ results received by ERM) 19 October 2012 (Laboratory results
received by ERM) |
|||
Monitoring Station |
E4 and E5 |
|||
Parameter(s) with Exceedance(s) |
Middle DO (mg/L) |
Bottom DO (mg/L) |
Depth-averaged Turbidity (NTU) |
Depth-averaged SS (mg/L) |
Action Levels |
5.62 mg/L |
5.46 mg/L |
1.44 NTU or 20% exceedance
of data at control station |
2.44 (mg/L) or 20% exceedance
of data at control station |
Limit Levels |
5.58 mg/L |
5.41 mg/L |
1.50 NTU and 30% exceedance
of data at control station |
2.48 (mg/L) and 30% exceedance
of data at control station |
Measured Levels at Impact Stations Where Exceedances Were Recorded |
1st Round |
Turbidity: E4=1.49 NTU; E5=1.63 NTU. SS: E4=2.47 mg/L;
E5=2.50 mg/L. |
||
2nd
Round |
Turbidity: E4=1.82 NTU; E5=1.67 NTU. SS: E4=2.80 mg/L; E5=2.73 mg/L. |
|||
3rd
Round |
Turbidity: E4=1.71 NTU; E5=1.55 NTU. SS: E4=2.68 mg/L; E5=2.57 mg/L. |
|||
4th
Round |
Turbidity: E4=1.73 NTU; E5=1.65 NTU. SS: E4=2.78 mg/L; E5=2.67 mg/L. |
|||
5th
Round |
Turbidity: E4=1.50 NTU; E5=1.58 NTU. SS: E4=2.52 mg/L; E5=2.57 mg/L; Middle DO: E4=5.60 mg/L. |
|||
6th
Round |
Turbidity: E4=1.57 NTU; E5=1.68 NTU. SS: E4=2.62 mg/L; E5=2.70 mg/L. Middle DO: E4=5.52 mg/L. |
|||
7th
Round |
Turbidity: E4=1.53 NTU; E5=1.71 NTU. SS: E4=2.55 mg/L; E5=2.68 mg/L. |
|||
8th
Round |
Turbidity: E4=1.52 NTU; E5=1.68 NTU. SS: E4=2.62 mg/L; E5=2.70 mg/L. Middle DO: E4=5.55 mg/L. Bottom DO: E4=5.44 mg/L. |
|||
Exceedances |
1st
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
||
2nd
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
|||
3rd
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
|||
4th
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
|||
5th
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5; Exceedance of Action Level in Middle DO: E4. |
|||
6th
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5; Exceedance of Action and Limit Levels in Middle DO: E4. |
|||
7th
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5. |
|||
8th
Round |
Exceedance of Action Level in Turbidity: E4 and E5; Exceedance of Action Level in SS: E4 and E5; Exceedance of Action and Limit Levels in Middle DO: E4; Exceedance of Action Level in Bottom DO: E4. |
Exceedances of the Action and Limit
Levels were recorded during the reporting period. The Event and Action Plan for the
identified exceedances were implemented and followed
the procedures as stipulated in the EM&A
Manual and Table 3.5. It was concluded that the exceedances were considered to reflect natural background
fluctuation rather than the impact caused by the Project (See Section 4.2 for details).
No non-compliance events
were recorded during the reporting period.
No complaints were received
during the reporting period.
No summons or prosecution
on environmental matters were received during the reporting period.
The
cable installation works will be continually conducted outside Zone C (from
Zone C eastward to the boundary Hong Kong marine waters).
Based on the current
construction programme, no impact water quality monitoring will be carried out since no
jetting works will be undertaken within Zone A, Zone B or Zone C.
This Weekly Impact
Monitoring Report presents the results of impact water quality monitoring
undertaken in Zone C during the period from 15 October 2012 to 21
October 2012 in accordance with the EM&A
Manual and the requirements under Environmental Permit (EP - 433/2011).
Water quality in Zone C was
generally stable throughout the sampling period. Neither sudden drop in dissolved oxygen
concentrations nor sharp increase in turbidity levels and suspended solid
levels were observed. Exceedances of Action and Limit Levels were recorded during
the reporting week, but they are considered to reflect natural background
fluctuation rather than impact caused by the Project.
It is concluded that no
deterioration of water quality was observed and hence the impact of the Project
on water quality is considered to be negligible.