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                   Site Description                                                                    

2.3                   Status of Environmental Approval Documents 

3                      Water Quality Monitoring Requirements               

3.1                   Monitoring Locations                                                       

3.2                   Monitoring Parameters                                                   

3.3                   Monitoring Equipment and Methodology               

4                      IMPLEMENTATION STATUS OF ENVIRONMENTAL MITIGATION measures  

5                      Post Project Monitoring Results                              

6                      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, Zone B and Zone C

Table 3.2        Equipment Used during the Impact Water Quality Monitoring

 

 

LIST OF ANNEXES

Annex A

Post Project Water Quality Monitoring Schedule

Annex B

QA/QC Results for Suspended Solids Testing

Annex C

Post Project Water Quality Monitoring Results

 

Executive Summary

The submarine-cable installation works for the Asia Submarine-cable Express (ASE) cable system commenced in October 2012 and were completed in January 2013.  This is the Post Project Water Quality Monitoring Report presenting the post-project water quality monitoring conducted during the period from 4 February 2013 to 20 February 2013 in accordance with the Monitoring and Audit Manual (EM&A Manual).

Water Quality

Nine monitoring events (days) were scheduled between 4 February 2013 and 20 February 2013, with three days for each of Zone A, Zone B and Zone C.  Monitoring events at all designated monitoring stations in the three zones were performed on schedule.

In general, the dissolved oxygen levels recorded during the Post Project Monitoring period were mostly higher to the results obtained during the baseline monitoring period.  Turbidity and suspended solid levels in Post Project Monitoring period were also slightly increased at all designated stations including the control stations.  After detailed analysis, it is considered that the overall changes in turbidity and SS were driven by natural fluctuations rather than the marine works of the Project. 

Conclusion

Upon completion of the Project, overall water quality at the impact stations in Zone A, Zone B and Zone C was found to be similar to that at control stations, which was higher in dissolved oxygen, turbidity and suspended solids when compared with the baseline data.  Given the fact that control stations are sufficiently far away from the cable alignment and water quality at these stations could not be affected by the Project, it is concluded that the overall variations in turbidity and SS reflected a natural phenomenon.  Hence, no deterioration of water quality was observed other than natural fluctuation.  The impact of the marine works of the Project on water quality is considered to be negligible.

 


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 Post Project Water Quality Monitoring Report, which summarises the results of post-project water quality monitoring finding as part of the EM&A programme during the reporting period from 4 February 2013 to 20 February 2013.  The Post Project Monitoring results are used to compare with the baseline monitoring results in order to investigate the impact of the project works on water quality in the vicinity of the project site from Tseung Kwan O eastward to the boundary of HKSAR waters.

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, and monitoring locations.

 

Section 4 :  Implementation Status of Environmental Mitigation Measures

Summarises the implementation of environmental protection measures during the reporting period.

 

Section 5 :  Post Project Monitoring Results

Summarises the monitoring results obtained in the reporting period for Zone A, Zone B and Zone C.

 

Section 6 :  Conclusions

Presents the key findings of the Post Project Monitoring results.

 

2                                           Project Information

2.1                                      Background

NTT Com Asia (NTTCA) proposed 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 landing site is at a new Beach Manhole (BMH) and the cable is ultimately connected with a Data Centre in Tseung Kwan O (TKO) Industrial Estate.  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 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 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 2.3 of the EM&A Manual, Post Project Monitoring of marine water quality should be undertaken after completion of the cable installation works at the same stations as baseline monitoring in Zone A, Zone B and Zone C, during mid-flood and mid-ebb tides. 

Baseline Monitoring was conducted in Zone A between 29 August 2012 and 3 September 2012 and the results were presented in Baseline Water Quality Monitoring Report (Zone A).  Baseline monitoring for Zone B was undertaken from 17 September 2012 to 21 September 2012 and Baseline Water Quality Monitoring Report (Zone B) presented the results of the monitoring data in Zone B.  Baseline monitoring was as well as carried out in Zone C between 24 September 2012 and 28 September 2012 and the results were presented in Baseline Water Quality Monitoring Report (Zone C).

Impact Monitoring in Zone A, Zone B and Zone C commenced on 8 October 2012 when the cable installation barge started to work in Zone A.  The cable installation works were completed on 29 December 2012 and the impact water quality monitoring ceased subsequently.

All marine works for the cable installation was completed in January 2013.  In accordance with the EM&A Manual , Post Project Water Quality Monitoring Report should be conducted within one month after completion of the marine works in Zone A, Zone B and Zone C.  This report presents the data obtained from Zone A (Figure 2.2), Zone B (Figure 2.3) and Zone C (Figure 2.4).  Results of the Post Project Monitoring data have been compared against the results of the baseline water quality monitoring in each zone.

2.2                                      Site Description

The cable installation ran from Tseung Kwan O, and extended 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 alignment of the cable is illustrated in Figure 2.1.

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

Forth Weekly Impact Water Quality Monitoring Report

 

Throughout the construction stage

Submitted on 8 January 2013


3                                           Water Quality Monitoring Requirements

3.1                                      Monitoring Locations

In accordance with the EM&A Manual, marine water samples for Post Project Monitoring were collected at the same stations as baseline monitoring situated around the submarine cable works in Zone A, Zone B and Zone C.  The locations of the sampling stations are shown in Figure 2.2 – Figure 2.4.

Zone A area:

·         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;

·         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; and

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

Zone B area:

·         C2 is a Control Station (approximately 3.4 km from the proposed cable alignment) for Zone B.  It is not supposed to be influenced by the cable laying works due to its remoteness to the construction works;

·         B1 is an Impact Station to monitor the impacts of cable installation works on the Big Wave Bay Beach;

·         B2 is an Impact Station to monitor the impacts of cable installation works on the Rocky Bay Beach;

·         B3 is an Impact Station to monitor the impacts of cable installation works on the Shek O Beach;

·         E1 is an Impact Station to monitor impacts of cable installation works on Cape d’Aguilar Marine Reserve;

·         E2 is an Impact Station to monitor the impacts of cable installation works on the coral communities at Tung Lung Chau;

·         E6 is an Impact Station to monitor the impacts of cable installation works on the coral communities at Tai Long Pai (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);

·         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;

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

·         G4 is a Gradient Station between E2 and the cable alignment; and

·         G7 is a Gradient Station between E1 and the cable alignment.

Zone C area:

·         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;

·         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; and

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

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

Table 3.1        Co-ordinates of Water Quality Impact Monitoring Stations in Zone A, Zone B and Zone C

Monitoring Station

Nature

Easting

Northing

Zone A

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

Zone B

B1

Impact Station (Beach)

843557

811853

B2

Impact Station (Beach)

844062

810369

B3

Impact Station (Beach)

843988

809902

E1

Impact Station (Marine Reserve)

845474

810605

E2

Impact Station (Coral Communities)

845203

815205

E6

Impact Station (Coral Communities)

845321

816718

E9

Impact Station (Coral Communities)

843557

811853

F1

Impact Station (Fish Culture Zone)

847196

811056

G3

Gradient Station

846099

812826

G4

Gradient Station

846583

810809

G7

Gradient Station

845946

808583

C2

Control Station

849603

811528

Zone C

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 post project water quality monitoring.

Table 3.2        Equipment Used during the Post Project 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

The water monitoring was carried out on nine occasions (days), with three occasions (days) for each zone (Annex A).  The intervals between two sets of monitoring were not less than 36 hours.  The water quality sampling was undertaken within a 4 hour window of 2 hour before and 2 hour after mid flood and mid-ebb tides.  The tidal range selected for the Post Project Monitoring was at least 0.5 m for both flood and ebb tides as far as practicable.

Reference were made to the predicted tides at Tai Miu Wan, which is the tidal station nearest to the Project Site, published on the website of the Hong Kong Observatory ([1]).  Based on the predicted tidal levels at Tai Miu Wan, the post-project water quality monitoring was conducted between 4 February 2013 and 20 February 2013, following the schedule presented in Annex A.  Schedule for Post Project Monitoring has been submitted to the Contractor, Independent Environmental Checker (IEC), Engineer Representative (ER) and Environmental Protection Department (EPD) one week prior to the commencement of the monitoring works.

 

Sampling Depths & Replication

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).

4                                           IMPLEMENTATION STATUS OF ENVIRONMENTAL MITIGATION measures

Mitigation measures for water quality control were recommended in the Project Profile (PP-452/2011) and Environmental Permit (EP- 433/2011).  The Contractor implemented the following measures during cable installation:

·         A silt curtain around the shore-end works site were employed in order to reduce the dispersion of sediments during the cable laying works;

·         The crane barge used for the transport of excavated materials was fitted with tight bottom seals in order to prevent leakage of material during loading and transport;

·         The crane barge was filled to a level, which ensures that material did not spill over during loading and transport to the disposal site and that adequate freeboard was maintained to ensure that the decks were not washed by wave actions;

·         The forward speed of the installation barge will be limited to a maximum of 1 km/ hour;

·         Water quality monitoring was carried out to verify that the project works will not result in any impacts to water quality, marine ecology and fisheries; and

·         Prevention of leakage from construction equipment to reduce the runoff entering the marine waters was incorporated as part of good working practices.

 

 


5                                           Post Project Monitoring Results

A total of nine monitoring occasions (days) were scheduled in the reporting period in February 2013 (Annex A).  Monitoring occasions at all designated monitoring stations within Zone A (conducted on 4, 6 and 8 February 2013), Zone B (conducted on 15, 18 and 20 February 2013) and Zone C (conducted on 14, 16 and 19 February 2013) were performed on schedule.  No major activities influencing the water quality were identified during the reporting period.

The Post Project Monitoring data are presented in Annex C and compared with baseline monitoring results in Figures C1-C18.  As shown in Figures C1-C18, post project monitoring results in Zone A, Zone B and Zone C have similar trends in all measured parameters in particular the level of dissolved oxygen, level of turbidity and suspended solids.  Therefore, monitoring results of these three parameters are discussed together as follows. 

The levels of dissolved oxygen measured during the post-project reporting period in all of the three zones at different sampling depths were higher than those obtained during the baseline monitoring periods.  Elevation of dissolved oxygen concentration was detected at all the impact and control stations during the Post Project Monitoring period.  DO levels recorded at the impact stations were of similar magnitude to those measured at the control stations (Figures C1, C2, C4 and C5 for Zone A, Figures C7, C8, C10 and C11 for Zone B, and Figures C13, C14, C16 and C17 for Zone C). 

Levels of turbidity and suspended solids measured during the post-project reporting period showed similar trends (Figures C3 and C6 for Zone A, Figures C9 and C12 for Zone B, and Figures C15 and C18 for Zone C).  Both of them in the three zones were elevated compared to those measured during the baseline monitoring periods.  This occurred to all the monitoring stations including control stations C1, C2 and C3, which are situated at a long distance from the submarine cable alignment and are not likely to be affected by the Project works.  Turbidity and suspended solids levels recorded at all the impact stations were of similar magnitude to those measured at the control stations during Post Project Monitoring period.  Actually this overall elevation in the level of turbidity and SS has been discussed in the Fourth Weekly Impact Water Quality Monitoring Report, which concluded the situation as a natural phenomenon and an overall elevation in the background turbidity and Depth-averaged SS levels in nearby marine water rather than related to the marine works of the Project. 

Given this information, the overall changes in turbidity and suspended solids levels during the post-project reporting period in all designated stations including control stations compared to baseline are likely to represent a natural phenomenon rather than due to the marine works of the Project.  It is considered that all these measurements were due to natural variations.

 

6                                           Conclusions

This Post Project Monitoring Report presents the EM&A work undertaken during the period from 4 February 2013 to 20 February 2013 in accordance with the EM&A Manual and the requirements under Environmental Permit (EP- 433/2011).

DO levels, turbidity and suspended solids in Zone A, Zone B and Zone C conducted within one month of the completion of the Project was found to be generally elevated compared to that before the commencement of Project works (i.e. baseline data).  After detailed analysis and comparison between the impaction stations and control stations, such overall variations in all sampling stations are considered to have been driven by natural fluctuations.

It is concluded that no deterioration of water quality was observed and hence the effect of the Project works on water quality at the Project site is considered to be negligible.


 



([1])        Hong Kong Observatory (2013) http://www.hko.gov.hk/tide/eQUBtide.htm [Accessed in February 2013]