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Contract No. HY/2011/03

Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road

Section between Scenic Hill and Hong Kong Boundary Crossing Facilities

 

 

 

 

 

 

Baseline Environmental Monitoring Report

 

5 November 2012

 

Revision 4

 

 

 

 

 

 

 

 

 

 

 

 

 

Main Contractor                                                                                                                     Designer

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Contents

Executive Summary.......................................................................................................................

1....... Introduction.. 1

1.1                          Background. 1

2....... Air Quality. 2

2.1                          Air Quality Monitoring Stations. 2

2.2                          Monitoring Methodology and Results. 2

2.3                          Action and Limit Levels. 2

2.4                          Event and Action Plan for Air Quality. 3

3....... Noise. 6

3.1                          Noise Monitoring Stations. 6

3.2                          Monitoring Methodology and Results. 6

3.3                          Action and Limit Levels. 7

3.4                          Event and Action Plan for Noise Monitoring. 7

4....... Water Quality. 8

4.1                          Water Quality Monitoring Stations. 8

4.2                          Monitoring Methodology and Results. 8

4.3                          Action and Limit Levels. 8

4.4                          Event and Action Plan for Water Quality Monitoring. 9

5....... Ecology. 12

5.1                          Monitoring Methodology and Results for Chinese White Dolphins. 12

5.2                          Event and Action Plan for Dolphin Monitoring. 12

6....... Mudflat Monitoring.. 12

6.1                          Mudflat Ecology Monitoring Methodology. 12

6.2                          Mudflat Ecology Monitoring Results. 13

6.3                          Water Quality Monitoring. 15

6.4                          Sedimentation Rate Monitoring. 15

6.5                          Event and Action Plan for Mudflat Monitoring. 16

7....... Conclusions. 18

 


 

Figures

 

Figure 6.1         Mudflat Survey Areas       

 

Appendices

 

Appendix A       Environmental Monitoring Stations

Appendix B       Intertidal Soft Shore Communities Survey Results

Appendix C       Draft Final report on Baseline Chinese White Dolphin Monitoring for Hong Kong ¡V Zhuhai ¡V Macao Bridge Hong Kong Projects 


Executive Summary

Prior to the commencement of Contract No. HY/2011/03 Hong Kong Zhuhai-Macao Bridge Hong Kong Link Road ¡V Section between Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract), Highways Department employed environmental specialist under Agreement No. CE35/2011 (EP) and Contract No. HY/2011/02 to carry out baseline environmental monitoring in air quality, noise water quality and ecology (Chinese White Dolphin) to facilitate early commencement of construction of Hong Kong Boundary Crossing Facilities (HKBCF) reclamation works and the Tuen Mum ¡V Chek Lap Kok Link (TM-CLKL) advance Southern Landfall reclamation works under Contract No. HY/2010/02.  The baseline environmental monitoring for air quality, noise, water quality and ecology (Chinese White Dolphin) was undertaken between September and November 2011 in accordance with requirements provided in the Environmental Monitoring and Audit (EM&A) Documents for the Hong Kong Link Road (HKLR), HKBCF and TM-CLKL.  A Baseline Environmental Monitoring Report (Version C) for Hong Kong-Zhuhai-Macao Bridge Hong Kong Projects ¡V Investigation (hereafter referred to as ¡§BEMR¡¨) was prepared to fulfil environmental permit conditions for HKBCF (including TM-CLKL southern landfall) project.  The BEMR presented monitoring locations, equipment, period, methodology, results and observations and is available from the website of Agreement No. CE 48/2011 (EP) Environmental Project Office (ENPO) for the Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road, Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities, & Tuen Mun-Chek Lap Kok Link ¡V Investigation:

http://www.hzmbenpo.com/

There are a total of two air quality monitoring stations, one noise monitoring station and thirteen water quality monitoring stations for this Contract No. HY/2011/03.  As these environmental monitoring locations were also covered in the BEMR, the baseline monitoring results for these environmental monitoring locations will be adopted for the Contract. 

This Baseline Environmental Monitoring Report has been prepared based on baseline mudflat monitoring results and baseline monitoring results presented in the BEMR.

The Action and Limit Levels for air quality, noise, water quality and ecology (Chinese White Dolphin) were developed based on the baseline monitoring results presented in the BEMR.

According to the baseline mudflat monitoring, surveys for horseshoe crabs, seagrass beds, intertidal soft shore communities as well as sedimentation rate monitoring were conducted in September 2012 at the specified mudflat survey areas.

The mudflat monitoring covered water quality monitoring data.  Reference was made to the water quality baseline monitoring data of the representative water quality monitoring station (i.e. SR3) as presented in the BEMR.  Baseline water quality monitoring in San Tau (monitoring station, SR3) was conducted in October 2011 prior to the construction of the HZMB.

 

 


1              Introduction

1.1                Background

1.1.1       The HZMB Hong Kong Link Road (HKLR) serves to connect the Hong Kong-Zhuhai-Macao Bridge (HZMB) Main Bridge at the Hong Kong Special Administrative Region (HKSAR) Boundary and the HZMB Hong Kong Boundary Crossing Facilities (HKBCF) located at the north eastern waters of the Hong Kong International Airport (HKIA).

1.1.2       The HKLR project has been separated into two contracts.  They are Contract No. HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between HKSAR Boundary and Scenic Hill.  The split of environmental monitoring and audit works for these two contracts have been clarified in Environmental Project Office¡¦s letter ref.: HYDHZMBEEM00_0_0424L.12 which was sent to Environmental Protection Department on 17 October 2012.    

1.1.3       China State Construction Engineering (Hong Kong) Ltd. was awarded by Highways Department as the Contractor to undertake the construction works of Contract No. HY/2011/03.

1.1.4       Prior to the commencement of the Contract, Highways Department employed environmental specialist under Agreement No. CE35/2011 (EP) to carry out baseline environmental monitoring in air quality, noise water quality and ecology (Chinese White Dolphin) to facilitate early commencement of construction of HKBCF reclamation works and the Tuen Mum ¡V Chek Lap Kok Link (TM-CLKL) advance Southern Landfall reclamation works under Contract No. HY/2010/02. 

1.1.5       The baseline environmental monitoring was undertaken between September and November 2011 in accordance with requirements in the Environmental Monitoring and Audit (EM&A) Documents for the HKLR, HKBCF and TM-CLKL.  A Baseline Environmental Monitoring Report (Version C) dated 8 March 2012 for Hong Kong-Zhuhai-Macao Bridge Hong Kong Projects ¡V Investigation (hereafter referred to as BEMR) was prepared to present monitoring locations, equipment, period, methodology, results and observations and is available from the website of Agreement No. CE 48/2011 (EP) Environmental Project Office (ENPO) for the Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road, Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities, & Tuen Mun-Chek Lap Kok Link ¡V Investigation:

http://www.hzmbenpo.com/

1.1.6       The relevant baseline monitoring results for air quality, noise, water quality and ecology (Chinese White Dolphin) presented in the BEMR have been adopted for this Contract as the baseline monitoring were undertaken prior to the commencement of the Contract and other nearby construction contracts in accordance with the EM&A requirements for the Contract. 

1.1.7       This Baseline Environmental Monitoring Report is prepared to document Action and Limit Levels for air quality, noise, water quality, ecology (Chinese White Dolphin) which are extracted from the BEMR and baseline mudflat monitoring results for the Contract.  The baseline levels will be used as the basis for compliance check during the impact monitoring for the Contract.


 

2              Air Quality

2.1                Air Quality Monitoring Stations 

2.1.1       There are a total of two air quality monitoring stations for the Contract and they are the same baseline monitoring stations presented in the BEMR.  The baseline air quality monitoring was undertaken approximately one year prior to the commencement of the Contract and other nearby construction contracts.  Therefore, the baseline monitoring results together with the Action and Limit Levels for these monitoring stations are considered applicable for the Contract.  The air quality monitoring stations for the Contract are listed in Table 2.1 and shown in Appendix A.

Table 2.1          Locations of Air Quality Monitoring Stations

Monitoring Stations

Location

AMS 5

Ma Wan Chung Village (Tung Chung)

AMS 6

Dragonair / CNAC (Group) Building (HKIA)

2.2                Monitoring Methodology and Results

2.2.1       The monitoring methodology and results are detailed in the BEMR.  The baseline monitoring results provided in Tables 3.4 and 3.5 of the BEMR will be adopted for the Contact as the baseline monitoring stations for the Contract are the same as those presented in the BEMR.  A summary of the average 1-hour TSP concentration and 24-hour TSP concentration is provided in Table 2.2 and Table 2.3, respectively.

Table 2.2          Summary of Baseline 1-hour TSP Monitoring Results

Monitoring Station

Average 1-hour TSP Concentration, µg/m3
(Range)

AMS 5

156.9

(82.2 ¡V 246.6)

AMS 6

169.2

(87.8 ¡V 273.2)

Table 2.3          Summary of Baseline 24-hour TSP Monitoring Results

Monitoring Station

Average 24-hour TSP Concentration, µg/m3
(Range)

AMS 5

52.9

(25.3 ¡V 74.2)

AMS 6

66.4

(35.2 ¡V 103.5)

2.3                Action and Limit Levels

2.3.1       The Action and Limit Levels for the Contract have been extracted from Tables 3.8 and 3.9 of the BEMR and summarised in Table 2.4 and Table 2.5.


 

Table 2.4         Action and Limit Levels for 1-hour TSP

Monitoring Station

Action Level, µg/m3

Limit Level, µg/m3

AMS 5

352

500

AMS 6

360

 

Table 2.5         Action and Limit Levels for 24-hour TSP

Monitoring Station

Action Level, µg/m3

Limit Level, µg/m3

AMS 5

164

260

AMS 6

173

2.4                Event and Action Plan for Air Quality

2.4.1       Should non-compliance of the air quality criteria occur, actions in accordance with the Action Plan in Table 2.6 shall be carried out.

Table 2.6         Event and Action Plan for Air Quality

Event

Action

ET

IEC

SO

Contractor

Exceedance of Action Level for one sample

1.   Identify source, investigate the causes of exceedance and propose remedial measures;

2.   Inform IEC and SO;

3.   Repeat measurement to confirm finding;

4.   Increase monitoring frequency to daily.

1.   Check monitoring data submitted by ET;

2.   Check Contractor¡¦s working method.

1.   Notify Contractor.

 

1.   Rectify any unacceptable practice;

2.   Amend working methods if appropriate.

Exceedance of Action Level for two or more consecutive samples

1.   Identify source;

2.   Inform IEC and SO;

3.   Advise the SO on the effectiveness of the proposed remedial measures;

4.   Repeat measurements to confirm findings;

5.   Increase monitoring frequency to daily;

6.   Discuss with IEC and Contractor on remedial actions required;

7.   If exceedance continues, arrange meeting with IEC and SO;

8.   If exceedance stops, cease additional monitoring.

1.   Check monitoring data submitted by ET;

2.   Check Contractor¡¦s working method;

3.   Discuss with ET and Contractor on possible remedial measures;

4.   Advise the ET on the effectiveness of the proposed remedial measures;

5.   Supervise Implementation of remedial measures.

1.   Confirm receipt of notification of failure in writing;

2.   Notify Contractor;

3.   Ensure remedial measures properly implemented.

 

1.   Submit proposals for remedial to SO within 3 working days of notification;

2.   Implement the agreed proposals;

3.   Amend proposal if appropriate.

 

Exceedance of Limit Level for one sample

1.   Identify source, investigate the causes of exceedance and propose remedial measures;

2.   Inform SO, Contractor and EPD;

3.   Repeat measurement to confirm finding;

4.   Increase monitoring frequency to daily;

5.   Assess effectiveness of Contractor¡¦s remedial actions and keep IEC, EPD and SO informed of the results.

1.   Check monitoring data submitted by ET;

2.   Check Contractor¡¦s working method;

3.   Discuss with ET and Contractor on possible remedial measures;

4.   Advise the SO on the effectiveness of the proposed remedial measures;

5.   Supervise implementation of remedial measures.

1.   Confirm receipt of notification of failure in writing;

2.   Notify Contractor;

3.   Ensure remedial measures properly implemented.

1.   Take immediate action to avoid further exceedance;

2.   Submit proposals for remedial actions to IEC within 3 working days of notification;

3.   Implement the agreed proposals;

4.   Amend proposal if appropriate.

Exceedance of Limit Level for two or more consecutive samples

1.   Notify IEC, SO, Contractor and EPD;

2.   Identify source;

3.   Repeat measurement to confirm findings;

4.   Increase monitoring frequency to daily;

5.   Carry out analysis of Contractor¡¦s working procedures to determine possible mitigation to be implemented;

6.   Arrange meeting with IEC and SO to discuss the remedial actions to be taken;

7.   Assess effectiveness of Contractor¡¦s remedial actions and keep IEC, EPD and SO informed of the results;

8.   If exceedance stops, cease additional monitoring.

1.   Discuss amongst SO, ET, and Contractor on the potential remedial actions;

2.   Review Contractor¡¦s remedial actions whenever necessary to assure their effectiveness and advise the SO accordingly;

3.   Supervise the implementation of remedial measures.

1.   Confirm receipt of notification of failure in writing;

2.   Notify Contractor;

3.   In consultation with the IEC, agree with the Contractor on the remedial measures to be implemented;

4.   Ensure remedial measures properly implemented;

5.   If exceedance continues, consider what portion of the work is responsible and instruct the Contractor to stop that portion of work until the exceedance is abated.

1.   Take immediate action to avoid further exceedance;

2.   Submit proposals for remedial actions to IEC within 3 working days of notification;

3.   Implement the agreed proposals;

4.   Resubmit proposals if problem still not under control;

5.   Stop the relevant portion of works as determined by the SO until the exceedance is abated.

Note:  ET ¡V Environmental Team, IEC ¡V Independent Environmental Checker, SO ¡V Supervising Officer

 


 

3              Noise 

3.1                Noise Monitoring Stations

3.1.1       There is one noise monitoring stations for the Contract and they are the same baseline monitoring stations presented in the BEMR.  The baseline noise monitoring was undertaken approximately one year prior to the commencement of the Contract and other nearby construction contracts.  Therefore, the baseline monitoring results together with the Action and Limit Levels for these monitoring stations are considered applicable for the Contract. The noise monitoring stations for the Contract are listed in Table 3.1 and shown in Appendix A.

Table 3.1          Locations of Noise Monitoring Stations

Monitoring Station

Location

NMS 5

Ma Wan Chung Village (Tung Chung)

3.2                Monitoring Methodology and Results

3.2.1       The monitoring methodology and results are detailed in the BEMR.  The baseline monitoring results provided in Tables 4.5 ¡V 4.7 of the BEMR will be adopted for the Contact as the baseline monitoring stations for the Contract is the same as those presented in the BEMR.  The baseline monitoring results are summarized in Table 3.2 to Table 3.4.

Table 3.2          Summary of Daytime (Normal Weekdays) Noise Monitoring Results

Monitoring Station

Daytime 0700-1900 hrs on normal weekdays
Range of Noise Level, dB(A)

Leq (30 min)

L10 (5 min)

L90 (5 min)

Mean

Max

Min

Mean

Max

Min

Mean

Max

Min

NMS 5

55.3

63.5

51.0

57.5

74.1

50.8

51.1

61.7

48.3

 

Table 3.3          Summary of Evening-Time & Daytime (Holiday) Noise Monitoring Results

Monitoring
Station

Evening-time 1900-2300 hrs on all days & Daytime 0700-1900 hrs on holidays
Range of Noise Level, dB(A)

Leq (30 min)

L10 (5 min)

L90 (5 min)

Mean

Max

Min

Mean

Max

Min

Mean

Max

Min.

NMS 5

55.4

68.2

48.9

58.2

67.8

49.7

51.0

57.5

48.1

 

Table 3.4          Summary of Night Time Noise Monitoring Results

Monitoring
Station

Night-time 2300-0700 hrs on the next day
Range of Noise Level, dB (A)

Leq (30 min)

L10 (5 min)

L90 (5 min)

Mean

Max

Min

Mean

Max

Min

Mean

Max

Min

NMS 5

53.7

67.5

48.6

55.7

71.5

49.5

50.0

55.0

48.0

 

3.3                Action and Limit Levels

3.3.1       The Action and Limit Levels for the Contract have been extracted from Table 4.9 of the BEMR and summarised in Table 3.5.

Table 3.5          Action Limit Levels for Noise during Construction Period

Monitoring Station

Time Period

Action Level

Limit Level

NMS5

0700-1900 hrs on normal weekdays

When one documented complaint is received

75 dB(A)

Notes:

If works are to be carried during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority have to be followed.

(*): Reduce to 65 dB (A) during school examination periods.

3.4                Event and Action Plan for Noise Monitoring

3.4.1       Should non-compliance of the criteria occur, action in accordance with the Event and Action Plan, as provided in Table 3.6, shall be carried out.

Table 3.6         Event and Action Plan for Construction Noise

Event

Action

ET

IEC

SO

Contractor

Exceedance of Action Level

1.   Identify source, investigate the causes of exceedance and propose remedial measures;

2.   Notify IEC and Contractor;

3.   Report the results of investigation to the IEC, SO and Contractor;

4.   Discuss with the Contractor and formulate remedial measures;

5.   Increase monitoring frequency to check mitigation effectiveness.

1.   Review the analysed results submitted by the ET;

2.   Review the proposed remedial measures by the Contractor and advise the SO accordingly;

3.   Supervise the implementation of remedial measures.

1.   Confirm receipt of notification of failure in writing;

2.   Notify Contractor;

3.   Require Contractor to propose remedial measures for the analysed noise problem;

4.   Ensure remedial measures are properly implemented

1.   Submit noise mitigation proposals to IEC;

2.   Implement noise mitigation proposals.

 


 

4              Water Quality

4.1                Water Quality Monitoring Stations

4.1.1       There are a total of thirteen water quality monitoring stations specified under the ER for the contract.  The baseline water quality monitoring was undertaken approximately one year prior to the commencement of the Contract and other nearby construction contracts.  Therefore, the baseline monitoring results together with the Action and Limit Levels for these monitoring stations are considered applicable for the Contract. They are listed in Table 4.1 and shown in Appendix A.

Table 4.1          Locations of the Water Quality Monitoring Stations

Monitoring Stations

Description

Coordinates

Easting

Northing

IS5

Impact Station (Close to HKLR construction site)

811579

817106

IS(Mf)6

Impact Station (Close to HKLR construction site)

812101

817873

IS7

Impact Station (Close to HKBCF construction site)

812244

818777

IS8

Impact Station (Close to HKBCF construction site)

814251

818412

IS(Mf)9

Impact Station (Close to HKBCF construction site)

813273

818850

IS10

Impact Station (Close to HKBCF construction site)

812577

820670

SR3

Sensitive receivers (San Tau SSSI)

810525

816456

SR4

Sensitive receivers (Tai Ho Inlet)

814760

817867

SR5

Sensitive receivers (Artificial Reef In NE Airport)

811489

820455

SR10A

Sensitive receivers (Ma Wan Fish Culture Zone)

823741

823495

SR10B

Sensitive receivers (Ma Wan Fish Culture Zone)

823686

823213

CS2

Control Station

805849

818780

CS(Mf)5

Control Station

817990

821129

 

4.2                Monitoring Methodology and Results

4.2.1       The monitoring methodology and results are detailed in the BEMR.  The baseline monitoring results provided in the BEMR will be adopted for the Contact as the baseline monitoring stations for the Contract is the same as those presented in the BEMR.  Appendices C3 and C4 of the BEMR detail the baseline monitoring results for the Contract.

4.3                Action and Limit Levels

4.3.1       The Action and Limit Levels for the Contract have been extracted from Table 5.6 of the BEMR and summarised in Table 4.2.


 

Table 4.2          Action and Limit Levels for Water Quality

Parameter (unit)

Water Depth

Action Level

Limit Level

Dissolved Oxygen (mg/L) (surface, middle and bottom)

Surface and Middle

5.0

4.2 except 5 for Fish Culture Zone

Bottom

4.7

3.6

Turbidity (NTU)

Depth average

27.5 or 120% of upstream control station¡¦s turbidity at the same tide of the same day

47.0 or 130% of turbidity at the upstream control station at the same tide of same day

Suspended Solid (SS) (mg/L)

Depth average

23.5 or 120% of upstream control station¡¦s SS at the same tide of the same day

34.4 or 130% of SS at the upstream control station at the same tide of same day and 10mg/L for Water Services Department Seawater Intakes

Notes:

               (1)    Depth-averaged is calculated by taking the arithmetic means of reading of all three depths.

               (2)    For DO, non-compliance of the water quality limit occurs when monitoring result is lower that the limit.

               (3)    For SS & turbidity non-compliance of the water quality limits occur when monitoring result is higher than the limits.

               (4)    All the figures given in the table are used for reference only and the EPD may amend the figures whenever it is considered as necessary.

               (5)    The 1 percentile of baseline data for dissolved oxygen (surface and middle) and dissolved oxygen (bottom) are 4.2mg/L and 3.6mg/L respectively.

4.4                Event and Action Plan for Water Quality Monitoring

4.4.1       Should non-compliance of the criteria occur, action in accordance with the Event and Action Plan, as provided in Table 4.3, shall be carried out.

Table 4.3          Event and Action Plan for Water Quality

Event

Action

ET Leader

IEC

SO

Contractor

Action level being exceeded by one sampling day

1.  Repeat in situ measurement on next day of exceedance to confirm findings;

2.  Identify source(s) of impact;

3.  Inform IEC, contractor and SO;

4.  Check monitoring data, all plant, equipment and Contractor's working methods.

1.  Check monitoring data submitted by ET and Contractor¡¦s working methods.

1.  Confirm receipt of notification of non-compliance in writing;

2.  Notify Contractor.

1.  Inform the SO and confirm notification of the non-compliance in writing;

2.  Rectify unacceptable practice;

3.  Amend working methods if appropriate.


 

Event

Action

ET Leader

IEC

SO

Contractor

Action level being exceeded by two or more consecutive sampling days

1.  Repeat measurement on next day of exceedance to confirm findings;

2.  Identify source(s) of impact;

3.  Inform IEC, contractor, SO and EPD;

4.  Check monitoring data, all plant, equipment and Contractor's working methods;

5.  Discuss mitigation measures with IEC, SO and Contractor;

6.  Ensure mitigation measures are implemented;

7.  Increase the monitoring frequency to daily until no exceedance of Action level;

 

1.  Check monitoring data submitted by ET and Contractor¡¦s working method;

2.  Discuss with ET and Contractor on possible remedial actions;

3.  Review the proposed mitigation measures submitted by Contractor and advise the SO accordingly;

4.  Supervise the implementation of mitigation measures.

1.  Discuss with IEC on the proposed mitigation measures;

2.  Ensure mitigation measures are properly implemented;

3.  Assess the effectiveness of the implemented mitigation measures.

1.  Inform the Engineer and confirm notification of the non-compliance in writing;

2.  Rectify unacceptable practice;

3.  Check all plant and equipment and consider changes of working methods;

4.  Submit proposal of additional mitigation measures to SO within 3 working days of notification and discuss with ET, IEC and SO;

5.  Implement the agreed mitigation measures.

Limit level being exceeded by one sampling day

1.  Repeat measurement on next day of exceedance to confirm findings;

2.  Identify source(s) of impact;

3.  Inform IEC, contractor, SO and EPD;

4.  Check monitoring data, all plant, equipment and Contractor's working methods;

5.  Discuss mitigation measures with IEC, SO and Contractor;

 

1.  Check monitoring data submitted by ET and Contractor¡¦s working method;

2.  Discuss with ET and Contractor on possible remedial actions;

3.  Review the proposed mitigation measures submitted by Contractor and advise the SO accordingly.

1.  Confirm receipt of notification of failure in writing;

2.  Discuss with IEC, ET and Contractor on the proposed mitigation measures;

3.  Request Contractor to review the working methods.

1.  Inform the SO and confirm notification of the non-compliance in writing;

2.  Rectify unacceptable practice;

3.  Check all plant and equipment and consider changes of working methods;

4.  Submit proposal of mitigation measures to SO within 3 working days of notification and discuss with ET, IEC and SO.

Limit level being exceeded by two or more consecutive sampling days

1.  Repeat measurement on next day of exceedance to confirm findings;

2.  Identify source(s) of impact;

3.  Inform IEC, contractor, SO and EPD;

4.  Check monitoring data, all plant, equipment and Contractor's working methods;

5.  Discuss mitigation measures with  IEC, SO and Contractor;

6.  Ensure mitigation measures are implemented;

7.  Increase the monitoring frequency to daily until no exceedance of Limit level for two consecutive days;

 

1.  Check monitoring data submitted by ET and Contractor¡¦s working method;

2.  Discuss with ET and Contractor on possible remedial actions;

3.  Review the Contractor¡¦s mitigation measures whenever necessary to assure their effectiveness and advise the SO accordingly;

4.  Supervise the implementation of mitigation measures.

1.  Discuss with IEC, ET and Contractor on the proposed mitigation measures;

2.  Request Contractor to critically review the working methods;

3.  Make agreement on the mitigation measures to be implemented;

4.  Ensure mitigation measures are properly implemented;

5.  Consider and instruct, if necessary, the Contractor to slow down or to stop all or part of the construction activities until no exceedance of Limit level.

1.  Take immediate action to avoid further exceedance;

2.  Submit proposal of mitigation measures to SO within 3 working days of notification and discuss with ET, IEC and SO;

3.  Implement the agreed mitigation measures;

4.  Resubmit proposals of mitigation measures if problem still not under control;

5.  As directed by the Engineer, to slow down or to stop all or part of the construction activities until no exceedance of Limit level.

 


 

5              Ecology

5.1                Monitoring Methodology and Results for Chinese White Dolphins

5.1.1       The monitoring methodology and results are detailed in Section 6 of the BEMR.  In total, 112 groups of Chinese White Dolphins, numbering 413 individuals, were observed during the three-month baseline survey.  Most were sighted in the West Lantau and Northwest Lantau regions.  The detailed monitoring results which were extracted from Appendix D of BEMR are presented in Appendix C. 

5.2                Event and Action Plan for Dolphin Monitoring

5.2.1       The Event and Action Plan for dolphin monitoring for the Contract have been extracted from Table 6.2 of the BEMR and summarised in Table 5.2.

Table 5.2          Event and Action Plan for Dolphin Monitoring

Event

Action*

ET

IEC

SO

Contractor

Dolphin numbers and behaviour patterns recorded in the construction and post-construction monitoring are significantly lower than or different from those recorded in the pre-construction monitoring.

Repeat statistical data analysis to confirm findings;

Review historical data to ensure differences are as a result of natural variation or previously observed seasonal differences;

Identify source(s) of impact; Inform the IEC, SO and Contractor; Check monitoring data;

Discuss additional dolphin monitoring and any other measures, with the IEC and Contractor.

Discuss monitoring with the ET and the Contractor;

Review proposals for additional monitoring and any other measures submitted by the Contractor and advise the SO accordingly.

Discuss with the IEC additional monitoring requirements and any other measures proposed by the ET;

Make agreement on the measures to be implemented

Inform the SO and confirm notification of the non-compliance in writing;

Discuss with the ET and the IEC and propose measures to the IEC and the SO;

Implement the agreed measures.

Notes:

ET ¡V Environmental Team

IEC ¡V Independent Environmental Checker

SO ¡V Supervising Officer

* Action to be instigated within 1 month of an event

 

6              Mudflat Monitoring

6.1                Mudflat Ecology Monitoring Methodology

Sampling Zone

6.1.1       There are two survey areas specified under the ER for the Contract, namely Tung Chung Bay and San Tau.  Tung Chung Bay survey area is divided into three sampling zones (TC1, TC2 and TC3) and there is one sampling zone at San Tau (ST).  Survey of horseshoe crabs, seagrass beds and intertidal communities were conducted in each sampling zone.  The locations of sampling zones are shown in Figure 6.1.  The pre-construction mudflat ecology monitoring was undertaken between 13 and 23 September 2012. 

Horseshoe Crabs

6.1.2       An active search method was adopted for horseshoe crab survey at each sampling zone. The survey was undertaken by 2 specialists each spending 2 to 3 hours at the site subject to the site and tidal conditions for two days.  Once a horseshoe crab was found, the species, size and inhabiting substrate, photographic record and respective GPS coordinate were recorded.

Seagrass Beds

6.1.3       An active search method was adopted for seagrass bed survey at each sampling zone.  The survey was undertaken by 2 specialists each spending 2 to 3 hours at the site subject to the site and tidal conditions for two days.  Once seagrass bed was observed, the species, the estimated area (m2), photographic record and respective GPS coordinate were recorded.

Intertidal Soft Shore Communities

6.1.4       The sandy shore of San Tau and Tung Chung Bay from the uppermost part of the shore and to the water edge was divided into three tidal zones ¡V upper, middle and lower zones, at each sampling zone, TC1, TC2, TC3 and ST.  A 100m transect was laid in each of the three tidal zones for fauna sampling.

6.1.5       At each sampling zone, three 100m horizontal transects will be laid at 2.0m, 1.5m and 1.0m above C.D.  Along each transect, ten random quadrats (0.5 m x 0.5m) were placed.  In each quadrat, the epifauna and infauna (within the top 5cm sediment) in each quadrat were identified and their numbers/coverage percentages were recorded.  One core of 10cm diameter x 20cm depth was also collected within each quadrat.  The sediments of the cores were sieved with 2mm mesh-size sieve and the biota inside was identified and counted.  Species and abundance of biota in both cores and quadrats were reported.

6.2                Mudflat Ecology Monitoring Results

Horseshoe Crabs

6.2.1       There were 1, 9 and 16 individuals of Tachypleus tridentatus observed at TC1, TC3 and ST respectively.  In addition, grouping of T. tridentatus was also observed at TC3 and ST while each group consisted of 2 to 4 individuals of T. tridentatus.  Survey results are presented in Table 3.1 of Appendix B.  No individuals of T. tridentatus were observed at TC2.

6.2.2       The prosomal width was also measured for each individual of T. tridentatus, and the range of prosomal width was from 8.45mm to 59.32mm, which corresponds to an age of 9 months to 8 years old.  The survey results have been grouped together for presentation.  Summary of prosomal width of horseshoe crab is shown in Table 6.1.

Table 6.1         Summary of Prosomal Width of Horseshoe Crab Survey

 

TC1

TC2

TC3

ST

No. of individuals

1

N/A

9

16

Mean prosomal width (mm)

28.14

N/A

42.65

24.41

Range of prosomal width (mm)

N/A

N/A

12.67 ¡V 59.32

8.45 ¡V 47.90

Search record
(individual hr-1 person-1)

0.25

N/A

1.50

2.67

 

Seagrass Beds

6.2.3       Four patches of Halophila ovalis were observed at ST while no any patches of H. ovalis were observed at the other sampling zones, TC1, TC2 and TC3.  The survey results have been grouped together for presentation.  The estimated total area and the mean area of H. ovalis as observed at ST were 332.3m2 and 83.1m2, respectively.  Survey results for seagrass beds are presented in Table 3.3 of Appendix B.

Intertidal Soft Shore Communities

6.2.4       A total of 15,188 individuals were recorded.  Mollusks were significantly abundant phylum (total individuals of 14,669; relative abundance of 96.6%, density of 489 individual m-2) followed by the second abundant group, arthropod (total individuals of 467; relative abundance of 3.1%, density of 16 individual m-2) at the sampling zones.  The summary of the total abundance and total biomass of every phylum is presented in Table 3.5 of Appendix B. The complete list of species recorded is shown in Appendix III of Appendix B.

6.2.5       In general, molluscs were the most dominant phylum (No. of individuals: 3011-4839; relative abundance of 93.6-98.5%, density of 401-645 individual m-2) followed by the second abundant phylum, arthropods (no. of individuals: 43-201; relative abundance of 1.2-6.0%, density of 6-27 individual m-2).  In addition, other phyla were very low in abundance across the four sampling zones (relative abundance of < 1%).  The number of individuals and relative abundance (%) of each phylum at every sampling zone were presented in Table 3.6 of Appendix B.

6.2.6       For TC1, gastropod Batillaria multiformis was the most dominant species (64-65 ind. m-2; relative abundance of 33-61%) at upper and middle tidal zones.  Rock oyster Saccostrea cucullata (12-43 ind. m-2; relative abundance of 15-22%) was the second abundant species at middle and lower tidal zones.  Gastropod Cerithidea djadjariensis was the most dominant species (18 ind. m-2; relative abundance of 21%) at lower tidal zone while gastropod Batillaria multiformis (12 ind. m-2; relative abundance of 14%) was the third dominant species at lower tidal zone.

6.2.7       For TC2, gastropod Cerithidea djadjariensis was the most dominant species at all tidal zones (31-60 ind. m-2; relative abundance of 36-51%).  The rock oyster Saccostrea cucullata (32 ind. m-2; relative abundance of 19%) was the second abundant species at middle tidal zone.

6.2.8       For TC3, gastropod Cerithidea djadjariensis (45-83 ind. m-2; relative abundance of 27-47%) and Batillaria multiformis (44-61 ind. m-2; relative abundance of 25-36%) were the two most dominant species at upper and middle tidal zones.  Rocky oyster Saccostrea cucullata (44 ind. m-2; relative abundance of 30%) and gastropod Monodonta labio (36 ind. m-2; relative abundance of 24%) were the most dominant species at lower tidal zone.

6.2.9       For ST, the upper tidal zone was dominated by gastropod Batillaria multiformis (40 ind. m-2; relative abundance of 26%) and Nassarius festivus (32 ind. m-2; relative abundance of 21%).  Gastropod Cerithidea djadjariensis (35 ind. m-2; relative abundance of 33%) was the first dominant species at middle tidal zone and second dominant species (10 ind. m-2; relative abundance of 20%) at lower tidal zone.  At middle tidal zone, the gastropod Cerithidea cingulata was the second abundant species (23 ind. m-2; relative abundance of 22%).  At lower tidal zone, rocky oyster Saccostrea cucullata was the most dominant species (18 ind. m-2; relative abundance of 37%).

6.2.10    There was no consistent pattern of species distribution observed across sampling zones and tidal levels in Tung Chung Wan and San Tau.  The species distribution might be determined by the type of substratum.  In general, gastropod Batillaria multiformis, Cerithidea djadjariensis and rocky oyster Saccostrea cucullata were the most common occurring species among the four sampling zones.  The abundant species (relative abundance >10%) at every sampling zone is presented in Table 3.7 of Appendix B.

6.2.11    The mean values of number of species, density, H¡¦ and J at every sampling zone are presented in Table 3.8 of Appendix B.  There was no obvious difference across the three tidal zones and sampling zones.  The number of species ranged 7-12, 5-9, 7-9 and 5-9 spp. 0.25 m-2 at TC1, TC2, TC3 and ST respectively.  The mean density ranged 340-780, 258-668, 587-705 and 192-612 ind. m-2 at TC1, TC2, TC3 and ST respectively.  The H¡¦ ranged 1.06-1.65, 0.93-1.43, 1.04-1.31 and 0.95-1.59 at TC1, TC2, TC3 and ST respectively.  The J ranged 0.54-0.73, 0.57-0.67, 0.55-0.60 and 0.61-0.73 at TC1, TC2, TC3 and ST respectively.  In general, there was no obvious difference of biodiversity among the four sampling zones based on the mean H¡¦ and J across tidal zones.  The values reflected a stable intertidal soft shore community with moderate ecological functions.

6.3                Water Quality Monitoring

6.3.1       The mudflat monitoring covered water quality monitoring data.  Reference was made to the water quality baseline monitoring data of the representative water quality monitoring station (i.e. SR3) as in the EM&A Manual.  The water quality monitoring location (SR3) is shown in Appendix A. 

6.3.2       Baseline water quality monitoring in San Tau (monitoring station SR3) was conducted in October 2011 prior to the construction of the HZMB.  The monitoring parameters included dissolved oxygen (DO), turbidity and suspended solids (SS).

6.3.3       The baseline monitoring results for SR3 were extracted from the BEMR and summarised below:

Table 6.2          Baseline Water Quality Monitoring Results (Depth Average)

Date

Mid Ebb Tide

Mid Flood Tide

DO Saturation (%)

DO (mg/L)

Turbidity (NTU)

SS (mg/L)

DO Saturation (%)

DO (mg/L)

Turbidity (NTU)

SS (mg/L)

6 Oct 2011

87.6

6.0

7.3

15.5

91.1

6.2

9.4

7.6

8 Oct 2011

89.2

6.0

4.6

7.4

95.7

6.4

9.7

12.0

10 Oct 2011

92.1

6.2

6.3

11.0

93.9

6.3

8.5

14.0

12 Oct 2011

100.4

7.2

5.6

6.7

92.8

6.6

7.7

11.5

14 Oct 2011

91.4

6.4

9.1

10.0

88.2

6.2

10.5

16.5

16 Oct 2011

96.9

6.8

14.1

13.0

91.0

6.5

8.5

9.7

18 Oct 2011

85.6

6.5

7.0

16.0

85.3

6.5

9.4

14.5

22 Oct 2011

93.2

7.4

9.2

12.5

92.5

7.3

10.3

18.0

25 Oct 2011

89.8

7.2

8.4

8.3

88.4

7.1

17.8

28.0

27 Oct 2011

94.1

6.4

6.4

31.0

100.7

6.9

19.7

20.5

29 Oct 2011

120.6

8.1

8.1

15.0

106.1

7.3

14.1

22.0

31 Oct 2011

84.1

6.8

6.8

21.0

88.8

7.1

19.0

21.0

Average

93.8

6.8

7.7

14.0

92.9

6.7

12.1

16.3

6.4                Sedimentation Rate Monitoring

Methodology

6.4.1       To avoid disturbance to the mudflat and nuisance to navigation, no fixed marker/monitoring rod was installed at the monitoring stations. A high precision Global Navigation Satellite System (GNSS) real time location fixing system (or equivalent technology) was used to locate the station in the precision of 1mm, which is reasonable under flat mudflat topography with uneven mudflat surface only at micro level.  This method has been used on Agricultural Fisheries and Conservation Department¡¦s (AFCD) project, namely Baseline Ecological Monitoring Programme for the Mai Po Inner Deep Bay Ramsar Site for measurement of seabed levels.

6.4.2       Measurements were taken directly on the mudflat surface.  The Real Time Kinematic GNSS (RTK GNSS) surveying technology was used to measure mudflat surface levels and 3D coordinates of a survey point.  The RTK GNSS survey was calibrated against a reference station in the field before and after each survey.  The reference station was a survey control point established by the Lands Department of the HKSAR Government or traditional land surveying methods using professional surveying instruments such as total station, level and/or geodetic global navigation satellite system.  The coordinates system was in HK1980 GRID system.  The reference control station was surveyed and established by traditional land surveying methods using professional surveying instruments such as total station, level and/or geodetic GNSS.  The accuracy was down to mm level and higher than the proposed RTK GNSS cm level so that the reference control station has relatively higher accuracy.  As the reference control station has higher accuracy, it was set as true evaluation relative to the RTK GNSS measurement.  All position and height correction were adjusted and corrected to the reference control station. 

6.4.3       The precision of the measured mudflat surface level reading (vertical precision setting) was within 10 mm (standard deviation) after averaging the valid survey records of the XYZ HK1980 GRID coordinates.  Each survey record at each station was computed by averaging at least three measurements that are within the above specified precision setting. Both digital data logging and written records were collected in the field.  Field data on station fixing and mudflat surface measurement were recorded.

Monitoring Locations

6.4.4       Four monitoring stations were established based on the site conditions for the sedimentation monitoring and are shown in Figure 6.1. 

Monitoring Results

6.4.5       The mudflat surface levels at the four established monitoring stations and the corresponding XYZ HK1980 GRID coordinates are presented in Table 6.3.

Table 6.3          Measured Mudflat Surface Level Results

Monitoring Station

Easting (m)

Northing (m)

Sedimentation Rate

(mPD)

Remarks

S1

810291.160

816678.727

0.950

Soft mudflat

S2

810958.272

815831.531

0.864

Soft mudflat

S3

810716.585

815953.308

1.341

Soft mudflat

S4

811221.433

816151.381

0.931

Soft mudflat

6.5                Event and Action Plan for Mudflat Monitoring

6.5.1       In the event of the impact monitoring results indicating that the density or the distribution pattern of intertidal fauna and seagrass is found to be significant different to the baseline condition (taking into account natural fluctuation in the occurrence and distribution pattern such as due to seasonal change), appropriate actions should be taken and additional mitigation measures should be implemented as necessary.  Data should then be re-assessed and the need for any further monitoring should be established.  The action plan, as given in Table 6.4, should be undertaken within a period of 1 month after a significant difference has been determined. 

Table 6.4          Event and Action Plan for Mudflat Monitoring

Event

ET

IEC

SO

Contractor

Density or the distribution pattern of horseshoe crab, seagrass or intertidal soft shore communities recorded in the impact or post-construction monitoring are  significantly lower than or different from those recorded in the baseline monitoring.

 

Review historical data to ensure differences are as a result of natural variation or previously observed seasonal differences;

Identify source(s) of impact;

Inform the IEC, SO and Contractor;

Check monitoring data;

Discuss additional monitoring and any other measures, with the IEC and Contractor.

Discuss monitoring with the ET and the Contractor;

Review proposals for additional monitoring and any other measures submitted by the Contractor and advise the SO accordingly.

 

Discuss with the IEC additional monitoring requirements and any other measures proposed by the ET;

Make agreement on the measures to be implemented.

 

Inform the SO and in writing;

Discuss with the ET and the IEC and propose measures to the IEC and the ER;

Implement the agreed measures.

 

Notes:

ET ¡V Environmental Team

IEC ¡V Independent Environmental Checker

SO ¡V Supervising Officer


 

7              Conclusions 

7.1.1       The baseline monitoring results for air quality, noise, water quality and ecology (Chinese White Dolphin) undertaken for Agreement No. CE35/2011 (EP) Baseline Environmental monitoring for Hong Kong ¡V Zhuhai ¡V Macao Bridge Hong Kong Projects ¡V Investigation has been adopted for the Contract as the baseline monitoring stations and requirements for the Contract are the same as those presented in the BEMR. 

7.1.2       For the water quality monitoring as required for mudflat monitoring, reference was made to the water quality baseline monitoring data of the representative water quality monitoring station (i.e. SR3) as required in the EM&A Manual.  Baseline water quality monitoring in San Tau (monitoring station, SR3) was conducted in October 2011 prior to the construction of the HZMB.  The monitoring parameters included DO, turbidity and SS.

7.1.3       For horseshoe crab survey under mudflat monitoring, there were 1, 9 and 16 individuals of Tachypleus tridentatus as observed at sampling zones, TC1, TC3 and ST, respectively during the survey.  Indeed, all horseshoe crabs, Tachypleus tridentatus, were in ages of 9 months to 8 years old based on the measurements of their prosomal widths.

7.1.4       Only one species of seagrass, Halophila ovalis, was recorded at one sampling zone, ST during the seagrass beds survey.  Four patches of this species of seagrass were observed and their estimated areas were also recorded of which the estimated total area was about 332.3m2.

7.1.5       For intertidal soft shore communities survey under mudflat monitoring, a total of 15,188 individuals were recorded.  Mollusks were significantly abundant phylum (total individuals of 14,669; relative abundance of 96.6%) followed by the second abundant group, arthropod (total individuals of 467; relative abundance of 3.1%) at the sampling zones.

7.1.6       Measurement of the mudflat surface level were conducted at four monitoring stations, S1, S2, S3 and S4, to establish the baseline level prior to the commencement of the construction works.  The mudflat sedimentation rate at S1, S2, S3, and S4 were 0.950mPD, 0.864mPD, 1.341mPD and 0.931mPD, respectively.


Figures

Figure 6.1.tiff


 

Appendix A

Environmental Monitoring Stations

Appendix B

Intertidal Soft Shore Communities Survey Results


 

Appendix C

Draft Final Report on Baseline Chinese White Dolphin Monitoring for
Hong Kong ¡V Zhuhai ¡V Macao Bridge Hong Kong Projects