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                   Impact 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        Water Quality Monitoring Stations

Table 3.2        Equipment Used during 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 in Turbidity on 5 February 2014

Table 4.3        Exceedances of Action Level in SS on 5 February 2014

Table 4.4        Site Works Undertaken on 5 February 2014

Table 4.5       Comparison of SS and Turbidity Levels at Gradient Stations and Impact Stations with Exceedances

 

List of Figures

Figure 2.1

ASE Submarine Cable System (Layout Plan)

Figure 2.2

Water Quality Monitoring Station (Zone A)

 

LIST OF ANNEXES

Annex A

Impact Water Quality Monitoring Schedule

Annex B

Calibration Reports of Multi-parameter Senor

Annex C

QA/QC Results for Suspended Solids Testing

Annex D

Impact Water Quality Monitoring Results

 

Executive Summary

The submarine cable installation works for the Asia Submarine-cable Express (ASE) cable system commenced on 12 January 2014.  This is the 2014 Fourth Weekly Impact Water Quality Monitoring Report presenting results and findings of the impact water quality monitoring conducted during the period from 2 to 8 February 2014 in accordance with the Updated Environmental Monitoring and Audit Manual (Updated EM&A Manual).

Summary of Construction Works Undertaken during the Reporting Period

During the reporting period, submarine cable installation works were conducted in Zone A (See Figure 2.2), which included diver inspections, equipment stowage (neither of which involved water jetting) and cable burial works (using water jetting).

Note no works were conducted on 2 February 2014, due to the Chinese New Year Holiday; nor from 6 to 8 February 2014, due to the completion of initial cable installation works on 5 February 2014.

Water Quality Monitoring

Three monitoring events were scheduled in the reporting period from 2 to 8 February 2014.  Monitoring events at designated monitoring stations in Zone A were performed on schedule on 3-5 February inclusive.

Note no monitoring works were conducted on 2 February 2014 inclusive due to the Chinese New Year Holiday; nor from 6 to 8 February 2014, due to the completion of initial cable installation works on 5 February 2014.

Environmental Non-conformance

Exeedances of Action Levels were recorded on 5 February 2014.  These exceedances are not considered to be caused by the cable installation works but are a reflection of natural background condition for the day as explained further in Section 4.2.

No exceedances of Limit Levels were recorded during the impact water quality monitoring period. 

No complaints or summons/prosecutions were received either during the reporting period. 

Future Key Issues

The initial cable installation works were completed on 5 February 2014 and the vessel is on standby in HK while testing and monitoring of the repaired cable is conducted.  Should there be a need for further work, the vessel will be mobilised again, subject to MDN issuance, and monitoring work will resume at that time.


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 re-installation of a damaged section of the telecommunication cable Asia-Submarine-cable Express (ASE).  The ASE cable is 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 2014 Fourth Weekly Impact Water Quality Monitoring Report, summarises the results of impact water quality monitoring as part of the EM&A programme during the reporting period from 2 to 8 February 2014.

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) installed 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 and was responsible for securing the approval to land the ASE cable in Tseung Kwan O, Hong Kong SAR (HKSAR).  The landing site is at a Beach Manhole (BMH) and ultimately the cable connects with a Data Centre in Tseung Kwan O (TKO) Industrial Estate which was completed in 2012.  It should be noted that Tseung Kwan O is currently the landing site for a number of submarine cables.  From Tseung Kwan O, the cable extends westward 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 and enters the South China Sea.  The total length of cable in Hong Kong SAR waters is approximately 33.5 km.  A map of the 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).  EPD subsequently issued an Environmental Permit (EP- 433/2011). 

Pursuant to Condition 2.4 of EP- 433/2011, an environmental monitoring and audit (EM&A) programme, as set out in the Environmental Monitoring and Audit Manual (EM&A Manual) is required for this Project.  Baseline data were collected prior to the start of cable installation works in 2012 and EM&A was conducted throughout the cable installation and after its completion in early 2013 as required in the EM&A Manual. 

Upon inspection in October 2013 the ASE cable was found to be damaged and a section within Zone A (see Figure 2.2) required re-installation.  The EM&A programme are therefore required to resume for the cable installation works in Hong Kong Waters (the “Project”) in accordance with Updated EM&A Manual. 

Baseline water quality update monitoring was conducted prior to the re-installation works and results summarise in the ‘Baseline Water Quality Monitoring Update Report (Zone A)’of December 2013. 

Impact monitoring started on 12 January 2014, when the cable installation works commenced in Zone A.  Impact monitoring is being conducted on a daily basis as the cable installation works proceed in Zone A, including three days within the reporting period.  The first week of impact monitoring was reported in the 2014 First Weekly Impact Water Quality Monitoring Report issued for the reporting period 12-18 January 2014 inclusive.  The second week of impact monitoring was reported in the 2014 Second Weekly Impact Water Quality Monitoring Report issued for the reporting period 19-25 January 2014 inclusive.  The third week of impact monitoring was reported in the 2014 Third Weekly Impact Water Quality Monitoring Report issued for the reporting period 26 January-1 February 2014 inclusive.  This Report presents the results and findings from the fourth week of impact monitoring, conducted for the reporting period 2-8 February 2014 , at the monitoring stations in Zone A.  No impact monitoring or cable installation works were conducted on 2 February 2014 due to the Chinese New Year Holiday; nor from 6 to 8 February 2014 due the completion of initial cable installation works on 5 February 2014.

2.2                                      Marine Construction Works Undertaken during Reporting Week

During the reporting period, submarine cable installation works were conducted in Zone A (See Figure 2.2), which included diver inspections, equipment stowage (neither of which involved water jetting work); and cable burial works using water jetting.

Note no works were carried out on 2 February 2014 due to the Chinese New Year Holiday and initial cable installation works were completed on 5 February 2014. 

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

 

Submitted on 18 September 2012

Updated EM&A Manual

-

Throughout the construction stage

Submitted December 2013

Baseline Water Quality Monitoring Update Report (Zone A)

-

Throughout the construction period for Zone A

Submitted on 5 December 2013


3                                             Impact Water Quality Monitoring Requirements

3.1                                      Monitoring Locations

In accordance with the Updated EM&A Manual, water quality monitoring samples were collected at the eleven (11) stations situated around the cable installation works in Zone A, as soon as the Project marine installation works started.  The locations of the sampling stations within Zone A are shown in Figure 2.2.

·      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 Project marine installation 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 Project marine installation 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 Project marine installation works due to its remoteness from the works.

The co-ordinates of the above monitoring stations in Zone A are listed in Table 3.1.

Table 3.1        Water Quality Monitoring Stations

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 Updated EM&A Manual.  Monitoring parameters are presented 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 Impact Water Quality Monitoring

Equipment

Model

Global Positioning Device

Garmin eTrex 10

Water Depth Gauge

Speedtech Instrument SM-5

Water Sampling Equipment

1520 Kemmerer Water Sampler

Salinity, DO, Temperature Measuring Meter

YSI Pro 2030

Current Velocity and Direction

Flow Probe FP111

Turbidity Meter

HACH Model 2100Q Turbid Meter

3.3.2                               Monitoring Methodology

Timing & Frequency

In-situ data and SS data were collected during Project marine 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 commenced when Project marine installation works started in Zone A.  (The daily sampling works will cease once no Project marine installation works are being undertaken within Zone A)

Due to the weather conditions and travelling time between stations, in-situ measurement and SS sampling were taken at the impact monitoring stations with approximately four-hour intervals 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 are being undertaken in Zone A

Temperature, Turbidity, Salinity, DO and SS

Gradient

G1, G2, G3

Impact

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

For in-situ measurements, duplicate readings were made at each water depth at each station.  Duplicate water samples were also collected at each water depth at each station for the laboratory analysis.

Depths

Measurements/ water samples were taken at each sampling station, at three depths, namely, 1 m below water surface, mid-depth and 1 m above sea bed, except where the water depth was less than 6 m, when the mid-depth sample may have been omitted.  For stations that are less than 3 m in depth, only the mid-depth sample was taken.

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 (Annex B).  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 C)

3.3.3                               Action and Limit Levels

The Action and Limit levels for Zones A, which were established based on the results of Baseline Update 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

(7.01 mg L-1), or

99%-ile of baseline data

(7.15 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

(5.91 mg L-1)

Surface and Middle(d)

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

(5.85 mg L-1)

Bottom

5%-ile of baseline data for bottom layers

(5.72 mg L-1)

Bottom

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

(5.62 mg L-1)

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

95%-ile of baseline data

(5.09 NTU), or

99%-ile of baseline data

(5.25 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 Updated 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 – Inform EPD and AFCD and confirm notification of the non-compliance in writing;

Step 3 - 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 4 - repeat measurements after implementation of mitigation for confirmation of compliance.

Step 5 - if non-compliance continues, increase measures in Step 3 and repeat measurements in Step 3.  If non-compliance occurs a third time, suspend cable laying operations.

Limit Level Exceedance

Undertake Steps 1-4 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 from 2 to 8 February 2014 (Annex A).  Impact monitoring works and cable installation works were not conducted on 2 February 2014 due to the Chinese New Year Holiday; nor from 6 to 8 February 2014 due to the completion of initial cable installation works on 5 February 2014.  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, so collections were made at least four (4) times per day.  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

The results of the impact monitoring and their graphical presentations are included in Annex D.  The monitoring results of Turbidity, SS and DO are discussed together as follows. 

The levels of depth-averaged Turbidity showed variation throughout the fourth week impact monitoring (Figure D1 of Annex D).  Observable differences of Turbidity levels among the stations (within the same monitoring round on the same monitoring day) were recorded on 5 February 2014.

Levels of depth-averaged SS measured during the fourth week impact monitoring showed fluctuation with time (Figure D1 of Annex D).  SS levels were recorded to be relative stable on 3 and 4 February 2014.  Differences of SS levels among the stations were detected on 5 February 2014.

The overall levels of DO at all the water depths (surface, mid-depth and bottom) during the fourth week impact monitoring were of similar magnitude at all the stations (Figure D2-D3 of Annex D).  Minor fluctuations of DO levels at all water depths were detected during the reporting period.  Minor differences of DO levels among the stations were also recorded at all water depths on 5 February 2014.

Despite relatively stable water quality, exceedances of the Action Levels in Turbidity and SS were recorded on 5 February 2014.  A summary of stations where exceedances were recorded is presented in Table 4.1. 


Table 4.1       Summary of Exceedances Occurring during the Reporting Week

 

 

Depth-averaged Turbidity

Depth-averaged SS

Date

Monitoring Time

Exceedance

 

 

Action Level (1)

Action Level (2)

5 February

7:00- 11:00 (First Round)

S1, S3

S1

11:00-15:00 (Second Round)

E7, F1, S2

F1, S2

15:00 -19:00 (Third Round)

E7, F1, E9, S3

N.A.

Note:

1    Action Level for Turbidity: 5.25 NTU, and 30% exceedance of value at any impact station compared with corresponding data from control station; and

2    Action Level for Turbidity: 7.01 mg/L, or 20% exceedance of value at any impact station compared with corresponding data from control station

4.2                                      Exceedances During Reporting Period

Exceedances of the depth-averaged Turbidity Action Levels were recorded at Impact Stations E7, E9, F1, S1, S2 and S3 in the 1st, 2nd, and 3rd sampling rounds on 5 February 2014 (Tables 4.1 and 4.2).  Exceedances of depth-averaged SS Action Levels were also detected at Impact Stations F1, S1 and S2 in the 1st, and 2nd sampling rounds on 5 February 2014 (Table 4.1 and 4.3).  Looking at Figure 2.2 the monitoring stations where exceedances were recorded are widely spread out within Zone A.

According to the daily site work report, all water jetting works were completed on 3 February 2014.  On 5 February 2014 only equipment stowage works were conducted which would not disturb seabed sediments nor cause any elevation of Turbidity and SS levels.  Detailed site works carried out on 5 February are reported in Table 4.4.    

Table 4.2        Exceedances of Action Level in Turbidity on 5 February 2014

Date

5 February 2014 (Measured)

6 February 2014 (In situ results received by ERM)

7 February 2014 (Laboratory results received by ERM)

Monitoring Stations with Exceedance(s)

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

Parameter(s) with Exceedance(s)

Depth-averaged Turbidity (NTU)

Action Level

5.09 NTU, or 20% exceedance of value at any impact station compared with corresponding data from control station

Limit Level

5.25 NTU, and 30% exceedance of value at any impact station compared with corresponding data from control station

Measured Levels at Control Station and Impact Stations Where Exceedances Were Recorded

1st Round

C1=3.08 NTU (Control Station);

S1= 4.17 NTU (35.4% exceedance of C1, but smaller than 5.25 NTU);

S3= 3.78 NTU (22.6% exceedance of C1).

2nd Round

C1=2.87 NTU (Control Station);

E7=3.45 NTU (20.3% exceedance of C1);

F1=3.92 NTU (36.8% exceedance of C1, but smaller than 5.25 NTU);

S2=3.85 NTU (34.2% exceedance of C1, but smaller than 5.25 NTU).

3rd Round

C1=2.92 NTU (Control Station);

E7=3.65 NTU (25.0% exceedance of C1);

F1=3.61 NTU (23.4% exceedance of C1);

E9=3.52 NTU (20.4% exceedance of C1);

S3=3.51 NTU (20.0% exceedance of C1).

Exceedances

1st Round

Exceedance of Action Level: S1 and S3.

2nd Round

Exceedance of Action Level: E7, F1, and S2.

3rd Round

Exceedance of Action Level: E7, F1, E9 and S3.

Table 4.3        Exceedances of Action Level in SS on 5 February 2014

Date

5 February 2014 (Measured)

6 February 2014 (In situ results received by ERM)

7 February 2014 (Laboratory results received by ERM)

Monitoring Stations with Exceedance(s)

S1, S2, and F1

Parameter(s) with Exceedance(s)

Depth-averaged SS (mg/L)

Action Level

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

Limit Level

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

Measured Levels at Control Station and Impact Stations Where Exceedances Were Recorded

1st Round

C1=4.00 mg/L (Control Station);

S1= 5.02 mg/L (25.4% exceedance of C1).

2nd Round

C1=3.75 mg/L (Control Station);

F1=4.75 mg/L (26.7% exceedance of C1);

S2=4.70 mg/L (25.3% exceedance of C1).

Exceedances

1st Round

Exceedance of Action Level: S1

2nd Round

Exceedance of Action Level: F1, and S2.

Table 4.4        Site Works Undertaken on 5 February 2014

Time

Site Works

00:01

Vessel continues standby to resume operations at 07:00

07:00

Toolbox talks completed

09:12

Commenced recovery of anchor 2.

09:40

Anchor 2 secured.

10:00

Hong Kong United 20 tug (HK20) connected tow. Barge on transit to China Merchant Wharf.

12:10

Thrusters online.

12:29

Tow line released.

12:36

First line ashore.

12:41

HK Captain reported barge alongside to HK Marine Department.

12:50

HK20 alongside to return tow bridle. HK Captain departs barge on HK20.

12:55

HK20 away.

13:00

Barge all fast alongside. Commenced in port de-mobilisation.

23:59

Vessel continued in port de-mobilisation.

Recorded depth-averaged SS and Turbidity levels at Gradient Stations G2 and G3 were lower than those at many of the Impact Stations with exceedances of Action Levels (S1, S2, S3 and F1) during the same monitoring round on the same day, despite being located closer to the cable installation work site (Table 4.5 and Figure 2.2).  Given this information, the exceedances of the Action Levels at these Impact Stations (S1, S2, S3 and F1) are not considered to be caused by the Project.

Table 4.5       Comparison of SS and Turbidity Levels at Gradient Stations and Impact Stations with Exceedances

Date

Monitoring Time

Depth-averaged Turbidity

(NTU)

Depth-averaged SS

(mg/L)

5 February

7:00- 11:00 (First Round)

S1 (4.17 NTU) vs G2 (3.63 NTU)

S3 (3.78 NTU) vs. G2 (3.63 NTU)

S1 (5.02 mg/L) vs. G2 (4.53 mg/L)

11:00-15:00 (Second Round)

F1 (3.92 NTU) vs. G3 (3.18 NTU)

S2 (3.85 NTU) vs. G2 (3.50 NTU)

F1 (4.75 mg/L) vs. G3 (4.07 mg/L)

S2 (4.70 mg/L) vs. G2 (4.28 mg/L)

15:00 -19:00 (Third Round)

S3 (3.51 NTU) vs. G2 (3.59 NTU)

N.A.

After consideration of all the information above in Section 4.2, the exceedances of the Action Levels at the Impact Stations are unlikely to be caused by the Project.  Rather the exceedances are considered to reflect natural background conditions for the day.

 

5                                             Environmental Non-CONFORMANCES

5.1                                      Summary of Environmental Exceedance

Exceedances of depth-averaged Turbidity and SS Action Levels were recorded on 5 February 2014.  After consideration of all the facts, the exceedances were not considered to be caused by the cable installation works but rather reflect the natural background condition for the day.

No exceedances of the Limit Levels were recorded during the reporting period.

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 initial cable installation works were completed on 5 February 2014 and the vessel is on standby in HK while testing and monitoring of the repaired cable is conducted.  Should there be a need for further work, the vessel will be mobilised again, subject to MDN issuance, and monitoring work will resume at that time.

6.2                                      Impact Monitoring Schedule For The Coming Reporting Period

No further impact monitoring works will be conducted in accordance with current working plans assuming the cable testing and monitoring indicate that no further repair works (cable installation works) are required.

 

7                                             Conclusions

This 2014 Fourth Weekly Impact Monitoring Report presents the results and findings of impact water quality monitoring undertaken in Zone A during the reporting period from 2 to 8 February 2014 in accordance with the Updated EM&A Manual and the requirements under Environmental Permit (EP - 433/2011) for the Project.

Water quality in Zone A was generally stable throughout the reporting period.  Levels of Turbidity, SS and DO levels showed fluctuation over time during the reporting period. 

Exceedances of the depth-averaged Turbidity and SS Action Levels were recorded on 5 February 2014, however, these exceedances were not considered to be caused by the cable installation works but rather are a reflection of the natural background condition for the day.

No exceedances of Limit Levels were recorded during the monitoring period.  No complaints or summons/prosecutions were received either during the reporting period. 

It is concluded the effect of the Project cable installation works on water quality around the Project site is negligible.