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 Impact Monitoring Stations in Zone A

Table 3.2        Equipment Used during the Impact Water Quality Monitoring

Table 3.3        Monitoring Frequency and Parameters for Impact Monitoring in Zone A

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

Table 4.2        Exceedances of Action Level on 27 December 2012

Table 4.3        Exceedances of Action and Limit Levels on 28 December 2012

Table 4.4        Exceedances of Action and Limit Levels on 29 December 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 Fourth Weekly Impact Water Quality Monitoring Report presenting the impact water quality monitoring conducted during the period from 24 December 2012 to 30 December 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 post-installation works, which involved diver jetting burial, were conducted in Zone A. 

Water Quality Monitoring

Three monitoring events were scheduled in the reporting period in Zone A.  Monitoring events at designated monitoring stations in Zone A were performed on schedule.

Environmental Non-conformance

Exceedances of Action Level 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

By the end of this reporting week, submarine-cable installation and post-installation works in which jetting works are involved have been completed.  If no accident, impact water quality monitoring would not be required for the Project henceforth.

 


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 Fourth 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 24 December 2012 to 30 December 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 (if any).

 

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. 

During this reporting week, the post-installation works that involved hand jetting were conducted in Zone A.  This Report therefore presents the monitoring results from the monitoring stations within Zone A.

2.2                                          Marine Construction Works Undertaken during Reporting Week

During the reporting period from 24 December 2012 to 30 December 2012, post-installation works that involved hand jetting by diver were conducted in Zone A.

2.3                                          Status of Environmental Approval Documents

A summary of the relevant permits, licences and reports on marine water quality 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

First Weekly Impact Water Quality Monitoring Report

 

Throughout the construction stage

Submitted on 19 October 2012

Second Weekly Impact Water Quality Monitoring Report

 

Throughout the construction stage

Submitted on 24 October 2012

Third Weekly Impact Water Quality Monitoring Report

 

Throughout the construction stage

Submitted on 24 December 2012


3                                                Impact Water Quality Monitoring Requirements

3.1                                        Monitoring Locations

In accordance with the EM&A Manual, marine water samples were collected at the stations situated around the submarine-cable protection works at the crossing point with DSD sewage pipe in Zone A.  Hand jetting was involved in the protection works.  The locations of the sampling stations within Zone A are shown in Figure 3.1.

·       E7 is the Impact Station located at Fat Tong Chau to monitor the impacts of cable installation works on the coral communities in the proximity;

·       E8 is an Impact Station to monitor the impacts of cable installation works on the coral communities along Junk Bay – South West;

·       E9 is an Impact Station to monitor the impacts of cable installation works on the coral communities at Cape Collison (the Gradient Station is not set due to the short distance of this Impact Station to nearby proposed cable works which may affect the cable laying works);

·       F1 is an Impact Station to monitor the impacts of cable installation works on the Tung Lung Chau Fish Culture Zone;

·       S1 is an Impact Station situated at the WSD Seawater Intake Point in Junk Bay.  It is located within 500 m north of the cable alignment at Junk Bay and set up to monitor the effect of cable laying works in the area; 

·       S2 is an Impact Station to monitor the impacts of cable installation works on the WSD Seawater Intake at Siu Sai Wan;

·       S3 is an Impact Station to monitor the impacts of cable installation works on the Pamela Youde Nethersole Eastern Hospital Cooling Water Intake at Heng Fa Chuen;

·       G1 is a Gradient Station between S1 and the cable alignment;

·       G2 is a Gradient Station between S2 and the cable alignment;

·       G3 is a Gradient Station between F1 and the cable alignment; and

·       C1 is a Control Station (approximately 3 km from the proposed cable alignment) for Zone A.  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 A are listed in Table 3.1.

Table 3.1        Co-ordinates of Water Quality Impact Monitoring Stations in Zone A

Monitoring Station

Nature

Easting

Northing

E7

Impact Station (Coral Community)

843779

814520

E8

Impact Station (Coral Community)

843111

815126

E9

Impact Station (Coral Community)

843557

811853

F1

Impact Station (Fish Culture Zone)

847196

811056

S1

Impact Station (Seawater Intakes)

847639

805900

S2

Impact Station (Seawater Intakes)

849587

805696

S3

Impact Station (Seawater Intakes)

845474

810605

G1

Gradient Station

845297

816282

G2

Gradient Station

844071

814784

G3

Gradient Station

846099

812826

C1

Control Station

842022

816547

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 diver jetting 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 E7, E8, E9, F1, S1, S2, S3, G1, G2, G3 and C1 commenced when the diver jetting for cable post-installation works was undertaken in Zone A.  The daily sampling works ceased once the diver jetting works in Zone A were completed.

Due to the weather conditions and travelling time between stations, in-situ and SS measurements were taken at the impact monitoring stations with an approximately four-hour interval in Zone A.  The monitoring frequency and parameters for Impact Monitoring are summarised in Table 3.3.

Table 3.3        Monitoring Frequency and Parameters for Impact Monitoring in Zone A

Zone

Station Type

Monitoring Station

Monitoring Frequency

Monitoring Parameter

A

Control

C1

Daily at a 4-hour interval while cable installation works were being undertaken in Zone A

Temperature, Turbidity, Salinity, DO and SS

Gradient

G1, G2, G3

Impact

E7, E8, E9, F1, S1, S2, S3,

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 A, which were established based on the results of Baseline Environmental Monitoring (Zone 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

SS in mgL-1

(Depth-averaged) (a) (c)

95%-ile of baseline data

(6.27 mg L-1), or

99%-ile of baseline data

(6.40 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

(4.36 mg L-1)

Surface and Middle(d)

5mg/L or 1%-ile of baseline for surface and middle layer

(4.25 mg L-1)

Bottom

5%-ile of baseline data for bottom layers

(4.39 mg L-1)

Bottom

2mg/L or 1%-ile of baseline data for bottom layer

(4.33 mg L-1)

Turbidity in NTU (Depth-averaged) (a) (c)

95%-ile of baseline data

(4.38 NTU), or

99%-ile of baseline data

(4.43 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 three monitoring events were scheduled in the reporting period between 24 December 2012 and 30 December 2012 (Annex A).  Monitoring events at all designated monitoring stations within Zone A 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 A at approximately 4-hour intervals (subject to the weather conditions and travelling time between stations) on a daily basis.  In general, the water quality of Zone A 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 were 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 Table 4.1.  Exceedances with detailed information of location and time were presented in Annex C. 

Table 4.1       Summary of Exceedances Occurring during the Reporting Week

Date

Surface DO

Middle DO

Bottom DO

Depth-averaged Turbidity

Depth-averaged SS

Exceedances

Action Level

Limit Level

Action Level

Limit Level

Action Level

Limit Level

Action Level

Limit Level

Action Level

Limit Level

27/12

 

 

 

 

 

 

 

 

E7, E8, E9, F1, S1, S2, S3

 

28/12

 

 

 

 

 

 

 

 

E7, E8, E9, F1, S1, S2, S3

 

29/12

 

 

 

 

 

 

 

 

E7, E8, E9, F1, S1, S2, S3

 

4.2                                        Exceedances During Reporting Period

4.2.1                                  Exceedances on 27 December 2012

Exceedances of the Action Level in depth-averaged SS were recorded at Impact Stations E7, E8, E9, F1, S1, S2 and S3 in the 1st, 2nd, 3rd and 4th sampling rounds on 27 December 2012 (Table 4.2). 

According to the daily barge operation report, there was preparation and equipment setting up works carried out by the Contractor before the hand jetting works, which commenced at 14:00.  The water jetting works stopped at approximately 16:00 due to strong current.  The actual time of hand jetting works on 27 December 2012 was between 14:00 to 16:00.  This period overlapped with the marine water quality monitoring.

Hand jetting works for the Project did not start when the exceedances were recorded at all monitoring stations (i.e. C1, G1, G2, G3, E8, S1, E7, F1, E9, S2 and S3) in the 1st round (07:00 – 10:50) of marine water quality monitoring. Therefore, the exceedances of the Action Level at in the 1st sampling round are considered as representing natural background fluctuations rather than the result of the cable protection (hand jetting) works.

For the exceedances in the 2nd and 3rd rounds of water quality sampling, considering the generally elevated Depth-averaged SS levels compared with the baseline data at all monitoring stations including the Control Station C1 to the east of Lei Yun Mun, it is unlikely that the localised and small scaled hand jetting (a total of only 13 m cable buried) can cause SS elevation of such scale.  Attention should also be given to the fact that such exceedances at all sampling stations occurred at the 1st round of water quality sampling before the hand jetting works started.  It is hence considered that the Depth-averaged SS exceedances at the 2nd and 3rd rounds of sampling may represent a natural phenomenon and overall elevation in the background Depth-averaged SS level, which is not related to the diver burial operation of the Project.

Given the discussion as above, the exceedances of the Action Level at all impact stations in the 4th round of sampling (19:10 – 23:06) are unlikely to be caused by the Project either.  Rather, the exceedances are considered to be a continuum of the performance of the natural background conditions for the day.

Table 4.2        Exceedances of Action Level on 27 December 2012

Date

27 December 2012 (Measured)

31 December 2012 (In situ results received by ERM)

2 January 2013 (Laboratory results received by ERM)

Monitoring Station

E8, S1, E7, F1, E9, S2 and S3

Parameter(s) with Exceedance(s)

Depth-averaged SS (mg/L)

Action Levels

6.27 mg/L, or 20% exceedance of value at any impact station compared with corresponding data from control station

Limit Levels

6.40 mg/L, and 30% exceedance of value at any impact station compared with corresponding data from control station

Measured Levels at Impact Stations Where Exceedances Were Recorded

1st Round

SS: E8=6.92 mg/L; S1=7.02 mg/L; E7=6.90 mg/L, F1=7.38 mg/L; E9=7.30 mg/L; S2= 6.92 mg/L; and S3=7.40 mg/L

2nd Round

SS: E8=6.93 mg/L; S1=7.15 mg/L; E7=7.03 mg/L, F1=7.17 mg/L; E9=7.02 mg/L; S2= 6.87 mg/L; and S3=7.25 mg/L

3rd Round

SS: E8=6.82 mg/L; S1=6.85 mg/L; E7=6.92 mg/L, F1=7.13 mg/L; E9=7.12 mg/L; S2= 6.95 mg/L; and S3=7.42 mg/L

4th Round

SS: E8=6.78 mg/L; S1=7.00 mg/L; E7=7.02 mg/L, F1=7.03 mg/L; E9=7.08 mg/L; S2= 6.87 mg/L; and S3=7.27 mg/L

Exceedances

1st Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

2nd Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

3rd Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

4th Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

4.2.2                                  Exceedances on 28 December 2012

Exceedances of the Action Level in depth-averaged SS were recorded at Impact Stations E7, E8, E9, F1, S1, S2 and S3 in the 1st, 2nd, 3rd and 4th sampling rounds on 28 December 2012 (Table 4.3).

According to the daily barge operation report of 28 December 2012, there was preparation and equipment setting up works carried out by the Contractor before the hand jetting works, which commenced at 10:30.  The water jetting works stopped at approximately 19:00 for the day.  The actual time of hand jetting works on 28 December 2012 was between 10:30 to 19:00.  This period overlapped with the marine water quality monitoring.. 

Hand jetting works for the Project did not start when the exceedances were recorded at all monitoring stations (i.e. C1, G1, G2, G3, E8, E7, F1, E9, S1 and S2) except S3 in the 1st round (07:00 – 10:21) of marine water quality monitoring.  Therefore, the exceedances of the Action Level at these stations in the 1st sampling round are considered as representing natural background fluctuations rather than a result of the cable protection (hand jetting) works.

For the exceedances at impact station S3 in the 1st round of water quality sampling and all monitoring stations in the 2nd and 3rd rounds, considering the generally elevated Depth-averaged SS levels compared with the baseline data at all monitoring stations including the Control Station C1 to the east of Lei Yun Mun, it is unlikely that the localised and small scaled hand jetting (a total of only 42 m cable buried) can cause SS elevation of such scale.  Attention should also be given to the fact that such exceedances at all sampling stations (except S3) occurred at the 1st round of water quality sampling before the hand jetting works started.  It is hence considered that the Depth-averaged SS exceedances at the 2nd and 3rd rounds of sampling may represent a natural phenomenon and overall elevation in the background Depth-averaged SS level, which is not related to the diver burial operation of the Project.

Given the discussion as above, the exceedances of the Action Level at all impact stations in the 4th round of sampling (19:10 – 23:04) are unlikely to be caused by the Project either.  Rather, the exceedances are considered to be a continuum of the performance of the natural background conditions for the day.

Table 4.3        Exceedances of Action and Limit Levels on 28 December 2012

Date

28 December 2012 (Measured)

31 December 2012 (In situ results received by ERM)

2 January 2012 (Laboratory results received by ERM)

Monitoring Station

E8, S1, E7, F1, E9, S2 and S3

Parameter(s) with Exceedance(s)

Depth-averaged SS (mg/L)

Action Levels

6.27 mg/L, or 20% exceedance of value at any impact station compared with corresponding data from control station

Limit Levels

6.40 mg/L, and 30% exceedance of value at any impact station compared with corresponding data from control station

Measured Levels at Impact Stations Where Exceedances Were Recorded

1st Round

SS: E8=6.95 mg/L; S1=6.87 mg/L; E7=7.03 mg/L, F1=6.97 mg/L; E9=7.10 mg/L; S2= 6.95 mg/L; and S3=6.85 mg/L

2nd Round

SS: E8=7.07 mg/L; S1=7.12 mg/L; E7=6.88 mg/L, F1=6.93 mg/L; E9=7.02 mg/L; S2= 6.95 mg/L; and S3=7.07 mg/L

3rd Round

SS: E8=7.02 mg/L; S1=6.70 mg/L; E7=7.00 mg/L, F1=7.03 mg/L; E9=7.03 mg/L; S2= 6.97 mg/L; and S3=6.98 mg/L

4th Round

SS: E8=6.92 mg/L; S1=6.90 mg/L; E7=6.82 mg/L, F1=6.87 mg/L; E9=6.93 mg/L; S2= 7.07 mg/L; and S3=6.95 mg/L

Exceedances

1st Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

2nd Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

3rd Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

4th Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

 

4.2.3                                  Exceedances on 29 December 2012

Exceedances of the Action Level in depth-averaged SS were recorded at Impact Station E7, E8, E9, F1, S1, S2 and S3 in the 1st, 2nd, 3rd and 4th sampling rounds on 29 December 2012 (Table 4.4).

According to the daily barge operation report of 29 December 2012, there was preparation and equipment setting up works carried out by the Contractor before the hand jetting works, which commenced at 10:30.  The water jetting works stopped at approximately 19:00 for the day.  The actual time of hand jetting works on 29 December 2012 was between 10:30 to 19:00.  This period overlapped with the marine water quality monitoring.

Hand jetting works for the Project did not start when the exceedances were recorded at all monitoring stations (i.e. C1, G1, G2, G3, E8, E7, F1, E9, S1 and S2) except S3 in the 1st round (07:00 – 10:22) of marine water quality monitoring.  Therefore, the exceedances of the Action Level at these stations in the 1st sampling round are considered as representing natural background fluctuations rather than a result of the cable protection (hand jetting) works.

For the exceedances at impact station S3 in the 1st round of water quality sampling and all monitoring stations in the 2nd and 3rd rounds, considering the generally elevated Depth-averaged SS levels compared with the baseline data at all monitoring stations including the Control Station C1 to the east of Lei Yun Mun, it is unlikely that the localised and small scaled hand jetting (a total of only 64 m cable buried) can cause SS elevation of such scale.  Attention should also be given to the fact that such exceedances at all sampling stations (except S3) occurred at the 1st round of water quality sampling before the hand jetting works started.  It is hence considered that the Depth-averaged SS exceedances at the 2nd and 3rd rounds of sampling may represent a natural phenomenon and overall elevation in the background Depth-averaged SS level, which is not related to the diver burial operation of the Project.

Given the discussion as above, the exceedances of the Action Level at all impact stations in the 4th round of sampling (19:08 – 22:55) are unlikely to be caused by the Project either.  Rather, the exceedances are considered to be a continuum of the performance of the natural background conditions for the day.

Table 4.4        Exceedances of Action and Limit Levels on 29 December 2012

Date

29 December 2012 (Measured)

2 January 2013 (In situ results received by ERM)

2 January 2013 (Laboratory results received by ERM)

Monitoring Station

E8, S1, E7, F1, E9, S2 and S3

Parameter(s) with Exceedance(s)

Depth-averaged SS (mg/L)

Action Levels

6.27 mg/L, or 20% exceedance of value at any impact station compared with corresponding data from control station

Limit Levels

6.40 mg/L, and 30% exceedance of value at any impact station compared with corresponding data from control station

Measured Levels at Impact Stations Where Exceedances Were Recorded

1st Round

SS: E8=7.25 mg/L; S1=7.08 mg/L; E7=7.02 mg/L, F1=7.12 mg/L; E9=6.98 mg/L; S2= 6.92 mg/L; and S3=6.97 mg/L

2nd Round

SS: E8=6.98 mg/L; S1=7.05 mg/L; E7=7.13 mg/L, F1=6.87 mg/L; E9=7.03 mg/L; S2= 6.98 mg/L; and S3=7.00 mg/L

3rd Round

SS: E8=7.13 mg/L; S1=6.92 mg/L; E7=6.98 mg/L, F1=7.38 mg/L; E9=7.23 mg/L; S2= 7.10 mg/L; and S3=7.02 mg/L

4th Round

SS: E8=7.13 mg/L; S1=7.10 mg/L; E7=6.98 mg/L, F1=7.05 mg/L; E9=7.10 mg/L; S2= 7.13 mg/L; and S3=7.18 mg/L

Exceedances

1st Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

2nd Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

3rd Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

4th Round

Exceedance of Action Level in SS: E8, S1, E7, F1, E9, S2 and S3.

 

 

5                                                Environmental Non-CONFORMANCES

5.1                                        Summary of Environmental Exceedance

Exceedances of the Action Level 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 3.4.  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

By the end of this reporting week, submarine-cable installation and post-installation works, in which jetting works are involved, have been completed. Given the completion of the marine construction phase involving jetting works of this project, no jetting works of any types are expected to be carried out except for any accidence in the future that requires the said task. 

6.2                                        Monitoring Schedule For The Coming Reporting Period

Since no jetting works are anticipated for the Project, impact water quality monitoring would not be required henceforth if no accidence.

7                                                Conclusions

This Weekly Impact Monitoring Report presents the results of impact water quality monitoring undertaken in Zone A during the period from 24 December 2012 to 30 December 2012 in accordance with the EM&A Manual and the requirements under Environmental Permit (EP - 433/2011).

Water quality in Zone A 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 Level 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.

By the end of this reporting week, submarine-cable installation and post-installation works, in which jetting works are involved, have been completed. Since no jetting works are anticipated for the Project in future, impact water quality monitoring would not be required henceforth if no accidence.