Contents

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                      Impact Water Quality Monitoring Requirements

3.1                   Monitoring Locations                                                       

3.2                   Monitoring Parameters                                                   

3.3                   Monitoring Equipment and Methodology               

4                      Impact Monitoring Results                                             

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                      Future Key Issues                                                                

6.1                   Key Issues For The Coming Reporting Period       

6.2                   Monitoring Schedule For The Coming Reporting Period        

7                      Conclusions                                                                           


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

Impact Water Quality Monitoring Schedule

Annex B

QA/QC Results for Suspended Solids Testing

Annex C

Impact Water Quality Monitoring Results

 

 

 

Executive Summary

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.

 


1                                             introduction

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).

1.1                                        Purpose of the Report

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.

1.2                                        Structure of the Report

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.

2                                             Project Information

2.1                                        Background

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.  .

2.2                                        Marine Construction Works Undertaken during Reporting Week

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.

2.3                                        Status of Environmental Approval Documents

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


3                                             Impact Water Quality Monitoring Requirements

3.1                                        Monitoring Locations

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. 

·      E4 is the Impact Station to monitor the impacts of cable installation works on the coral communities at the coast of Sung Kong;

·      E5 is the Impact Station to monitor the impacts of cable installation works on the coral communities at the coast of Waglan Island;

·      G5 is the Gradient Station between E4 and the alignment;

·      G6 is the Gradient Station between E5 and the alignment; and

·      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

3.2                                        Monitoring Parameters

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:

·      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, special phenomena and work activities undertaken around the monitoring and works area that may influence the monitoring results.

3.3                                        Monitoring Equipment and Methodology

3.3.1                                  Monitoring Equipment

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

 

3.3.2                                  Monitoring Methodology

Timing & Frequency

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.

Depths

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.

Sampling/ Testing Protocols

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° 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.

Laboratory 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)

3.3.3                                  Action and Limit Levels

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.

 

3.3.4                                  Event and Action Plan

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 – 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 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.

4.1                                        Data Collected During 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

 

4.2                                        Exceedances During Reporting Period

4.2.1                                  Exceedances on 15 October 2012

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 – 09:00), 2nd (09:07 – 10:07) and 8th (21:01 – 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.

4.2.2                                  Exceedances on 16 October 2012

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 – 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.

5                                             Environmental Non-CONFORMANCES

5.1                                        Summary of Environmental Exceedance

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).

5.2                                        Summary of Environmental Non-compliance

No non-compliance events were recorded during the reporting period.

5.3                                        Summary of Environmental Complaint

No complaints were received during the reporting period.

5.4                                        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 Reporting Period

The cable installation works will be continually conducted outside Zone C (from Zone C eastward to the boundary Hong Kong marine waters). 

6.2                                        Monitoring Schedule For The Coming Reporting Period

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.

7                                             Conclusions

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.