Table of Content

 

COVER

EXECUTIVE SUMMARY

1.             INTRODUCTION.. 1

1.1       Background  1

1.2       Project Organisation  1

1.3       Construction Works undertaken during the Reporting Month  1

1.4       Summary of EM&A Requirements  3

2.             AIR QUALITY.. 6

2.1       Monitoring Requirements  6

2.2       Monitoring Locations  6

2.3       Monitoring Equipment 6

2.4       Monitoring Parameters, Frequency and Duration  7

2.5       Monitoring Procedures and Calibration Details  8

2.6       Results And Observations  8

3.             NOISE.. 11

3.1       Monitoring Requirements  11

3.2       Monitoring Locations  11

3.3       Monitoring Equipment 11

3.4       Monitoring Parameters, Frequency and Duration  12

3.5       Monitoring Procedures and Calibration Details  12

3.6       Results & Observations  12

4.             WATER QUALITY MONITORING.. 14

4.1       Monitoring Requirements  14

4.2       Monitoring Locations  14

4.3       Monitoring Equipment 15

4.4       Monitoring Parameters, Frequency and Duration  15

4.5       Monitoring Procedures and Calibration Details  16

4.6       Results and Observations  19

5.             ENVIRONMENTAL AUDIT.. 23

5.1       Review of Environmental Monitoring Procedures  23

5.2       Assessment of Environmental Monitoring Results  24

5.3       Site Environmental Audit 25

5.4       Status of Environmental Licensing and Permitting  25

5.5       Implementation Status of Environmental Mitigation Measures  26

5.6       Implementation Status of Action/Limit Plans  26

5.7       Implementation Status of Environmental Complaint Handling Procedures  26

6.             FUTURE KEY ISSUES. 28

6.1       Status of Natural Gas supply  28

6.2       Key Issues for the Coming Month  28

6.3       Monitoring Schedules for the Next 3 Months  28

6.4       Construction Program for the Next 3 Months  28

7.             CONCLUSION.. 29

 

 

List of Tables

 

Table 1.1          Construction Activities and Their Corresponding Environmental Mitigation Measures

Table 2.1          Air-Quality Monitoring Locations

Table 2.2          Air Quality Monitoring Equipment

Table 2.3          Air Quality Monitoring Parameter, Duration and Frequency

Table 3.1          Noise Monitoring Locations

Table 3.2          Noise Monitoring Equipment

Table 3.3          Noise Monitoring Duration and Parameter

Table 4.1          Water Quality Monitoring Locations

Table 4.2          Water-Quality Monitoring Equipment

Table 4.3          Water Quality Monitoring Parameters and Frequency

Table 4.4          Laboratory Analysis Methodologies of Marine Water Samples

Table 5.1          Summary of AL Level Exceedances on Monitoring Parameters

Table 5.2          Estimated Amounts of Waste Generated in April 2001

Table 5.3          Summary of Environmental Licensing and Permit Status

Table 5.4          Environmental Complaints / Enquiries Received in April 2001

Table 5.5          Outstanding Environmental Complaints / Enquiries Received Before

 

 

List of figures

 

Figure 1.1         Layout of Work Site

Figure 1.2         Location of Dumping Area

Figure 2.1         Location of Air Quality Monitoring Stations

Figure 3.1         Location of Noise Monitoring Stations

Figure 4.1         Location of Water Quality Monitoring Stations


 

Appendices

 

Appendix A      Organization Chart

Appendix B      Amount of Dredged and Dumped Marine Sediment

Appendix C      Action and Limit Levels for Air Quality, Noise, Water quality Monitoring

Appendix D      Environmental Monitoring Schedule

Appendix E      Air Quality Monitoring Results for April 2001

Appendix F      Noise Monitoring Results for April 2001

Appendix G      Water Quality Monitoring Results for April 2001

Appendix H      The QA/QC Procedures and Results

Appendix I       Event/Action Plans

Appendix J       Site Audit Summary

Appendix K     Summary of EMIS

Appendix L      Tentative Construction Programme

 

 


EXECUTIVE SUMMARY

 

The site formation work for Lamma Extension started on 2nd April 2001 and the actual dredging work was conducted on 12th April 2001.  This is the first monthly Environmental Monitoring and Audit (EM&A) report for the Project “Construction of Lamma Power Station Extension” prepared by the Environmental Team (ET).  This report presents the results of impact monitoring on air quality, noise and marine water quality for the said project in April 2001.

 

Air, noise and water quality monitoring were performed. The results were checked against the established Action/Limit (AL) levels.  An on-site audit was conducted once per week. The implementation status of the environmental mitigation measures, Event/Action Plan and environmental complaint handling procedures were also checked.

 

Environmental Monitoring Works

One marine water quality monitoring on 11th April 2001 was cancelled due to adverse weather conditions.  Except this, all monitoring work at designated stations was performed on schedule in the reporting period.    

 

Air Quality

No exceedance of Action and Limit levels for air quality was recorded in the month.

 

Noise

Construction work was carried out during the restricted hours including evening time and holidays (effective from 2nd April 2001) and night-time (effective from 24th April 2001).  Four cases of Limit level exceedances on 5-min Leq noise level were reported at Long Tsai Tsuen/Hung Shing Ye in the reporting month.  It is suspected that two of them were caused by birds’ activities.  As the limit level exceedances were not related to construction activities, no further action can be devised.

  

Water Quality

A total of twenty-eight cases of Action level exceedances and seventeen cases of Limit Level exceedance for water quality were recorded in the reporting month.  All of these exceedances were considered not related to site activities.  No further action was required.

 

Site Environmental Audit

Site audits were carried out on a weekly basis to monitor environmental issues on the construction site.  The site conditions were generally satisfactory.  All required mitigation measures were implemented.

 


 

Environmental Licensing and Permitting

 

Description

Permit No.

Valid Period

Issued To

Date of Issuance

From

To

Varied Environmental Permit

EP-071/2000/A

22/12/00

-

HEC

22/12/00

Construction Noise Permit

GW-UW0109-01

 

GW-UW0163-01

02/04/01

 

24/04/01

01/10/01

 

08/10/01

Contractor

 

Contractor

 

31/03/01

 

24/04/01

Dumping Permit

EP/MD/01-174

07/04/01

06/10/01

Contractor

27/03/01

 

Implementation Status of Environmental Mitigation Measures

Environmental mitigation measures for the dredging activities were implemented in the reporting month. 

 

Environmental Complaints

No complaint was received in the reporting month.

 

Concluding Remarks

The environmental performance of the project was generally satisfactory.



1.             INTRODUCTION

 

 

1.1         Background

 

The Environmental Team (hereinafter called the “ET”) was formed within the Hongkong Electric Co. Ltd (HEC) to undertake Environmental Monitoring and Audit for Construction of Lamma Power Station Extension” (hereinafter called the “Project”).  Under the requirements of Section 6 of Environmental Permit EP-071/2000/A, an EM&A programme for impact environmental monitoring as set out in the EM&A Manual (Construction Phase) is required to be implemented.  In accordance with the EM&A Manual, environmental monitoring of air quality, noise and water quality and regular environmental audits are required for the Project.

 

The Project involves the construction of a gas-fired power station employing combined cycled gas turbine technology, forming an extension to the existing Lamma Power Station.  The following outlines the key elements of the Project including the construction activities associated with the transmission system and submarine gas pipeline.

 

          dredging and reclamation to form approximately 22 hectares of usable area;

          construction of six 300MW class gas-fired combined cycle units;

          construction of a gas receiving station;

          construction of a new transmission system linking the Lamma Extension to load centres on Hong Kong Island;

          laying of a gas pipeline for the supply of natural gas to the new power station

 

This report summarizes the environmental monitoring and audit work for the Project for the month of April 2001

 

 

1.2         Project Organisation

 

An Environmental Management Committee (EMC) has been set up in HEC to oversee the Project.  The management structure includes the following:

 

          Environmental Protection Department (The Authority);

          Environmental Manager (The Chairman of the Environmental Management Committee);

          Engineer;

          Independent Environmental Checker (IEC);

          Environmental Team (ET);

          Contractor.

 

The project organisation chart for the construction EM&A programme is shown in Appendix A.

 

 

1.3         Construction Works undertaken during the Reporting Month

 

The site formation work for Lamma Extension started on 2nd April 2001 and the actual dredging work commenced on 12th April 2001.  Construction activities undertaken during the reporting month were dredging and dumping of dredged mud.   A Layout Plan showing the dredging locations for the Project is shown in Figure 1.1.  The total volume of dredged material from 12th to 30th April 2001 was 214,132m3.  No filling activities were undertaken in the month. Uncontaminated materials were dumped at the assigned location within the South Cheung Chau Spoil Disposal Area and the total dumped volume in April 2001 was 214,132m3.  Figure 1.2 shows all dumping locations for this project.  Daily records of dredged / dumped volume are presented in Appendix B.

 

The main construction activities carried out during the reporting month and the corresponding environmental mitigation measures are summarized in Table 1.1.  The implementation of major mitigation measures in the month is provided in Appendix K.

 

Table 1.1    Construction Activities and Their Corresponding Environmental Mitigation Measures

 

Item

Construction Activities

Environmental Mitigation Measures

1

Dredging

The following mitigation measures related to dredging have been implemented:

 

  1. Installation of silt curtains;
  2. Allowable equipment configuration and maximum rates of dredging;
  3. Appropriate procedures for preventing leakage/spillage of dredged materials during loading and transport;
  4. Dredging equipment equipped with silencers or mufflers.

 

 


 

1.4         Summary of EM&A Requirements

 

The EM&A program requires environmental monitoring for air, noise and water quality.  Regular environmental site audits for air quality, noise, water quality and waste management were carried out.  The detailed EM&A monitoring work for air quality, noise and water quality are described in Sections 2, 3 and 4 respectively.

 

The following environmental audits are summarized in Section 5 of this report:

 

          Environmental monitoring results;

          Waste Management Records;

          Weekly site audit results;

          The status of environmental licensing and permits for the Project;

          The implementation status of environmental protection and pollution control/ mitigation measures.

 

Future key issues will be reported in Section 6 of this report.

 


 

 

Figure 1.1    Layout of Work Site


 

Figure 1.2    Location of Dumping Area

 



2.             AIR QUALITY

 

 

2.1         Monitoring Requirements

 

1-hour and 24-hour TSP monitoring at agreed frequencies were conducted to monitor air quality.  The impact monitoring data were checked against the Action/Limit Levels as determined in the Baseline Monitoring Report (Construction Phase).  Appendix C shows the established Action/Limit Levels for Air Quality.

 

 

2.2         Monitoring Locations

 

Three dust monitoring locations were selected for 1-hour TSP sampling (AM1, AM2 & AM3) whereas four monitoring locations were selected for 24-hour TSP sampling (AM1, AM2, AM3 and AM4).  Table 2.1 tabulates the monitoring stations.  The locations of the monitoring stations are shown in Figure 2.1.

 

Table 2.1    Air-Quality Monitoring Locations

 

Location I.D.

Description

AM1

Reservoir

AM2

East Gate

AM3

Ash Lagoon

AM4

Tai Yuen Village

 

 

2.3         Monitoring Equipment

 

Continuous 24-hour TSP air quality monitoring was performed using the GS2310 High Volume Air Samplers (HVAS), Partisol Model 2000 Sampler and the MINIVOL Portable Sampler at AM1&2, AM3 and AM4 respectively.  TEOM Model 1400a continuous dust monitors were used to carry out the 1-hour TSP monitoring at AM1, AM2 and AM3.  Table 2.2 summarises the equipment used in the dust monitoring.

 


Table 2.2    Air Quality Monitoring Equipment

 

Equipment

Model and Make

24-hour sampling:

HVAS Sampler

 

 

Partisol Air Sampler

 

 

MINIVOL Portable Sampler

 

1-hour sampling:

Continuous TSP Dust Meter

 

Model GS2310

Anderson Instruments Inc.

 

Partisol Model 2000

Rupprecht & Patashnick

 

AIRMETRICS

 

 

TEOM Model 1400a

Rupprecht & Patashnick

 

 

2.4         Monitoring Parameters, Frequency and Duration

 

Table 2.3 summarises the monitoring parameters, duration and frequency of air quality monitoring.  The monitoring schedule for the reporting month is shown in Appendix D.

 

Table 2.3    Air Quality Monitoring Parameter, Duration and Frequency

 

Monitoring Stations

Parameter

Duration

Frequency

AM1

1-hour TSP

1

3 times every 6 days

24-hour TSP

24

Once every 6 days

AM2

1-hour TSP

1

3 times every 6 days

24-hour TSP

24

Once every 6 days

AM3

1-hour TSP

1

3 times every 6 days

24-hour TSP

24

Once every 6 days

AM4

24-hour TSP

24

Once every 6 days

 

 


2.5         Monitoring Procedures and Calibration Details

 

24- hour TSP Monitor:

 

Preparation of Filter Papers

 

          Visual inspection of filter papers was made to ensure that no pinholes, tears and creases were found;

          The filter papers were then labelled before sampling.

          The filter papers were equilibrated at room temperature and relative humidity < 50% for at least 24 hours before weighing.

 

Field Monitoring

 

          During collection of the sampled filter paper, the information on the elapse timer was logged.  Site observations around the monitoring stations, which might have affected the monitoring results, were also recorded.  Major pollution sources, if any, would be identified and reported.  The flow record chart for the previous sampling was checked to see if there was any abnormality.

          The post-sampling filter papers were removed carefully from the filter holder and folded to avoid loss of fibres or dust particles from the filter papers;

          The filter holder and its surrounding were cleaned;

          A pre-weighed blank filter paper for the next sampling was put in place and aligned carefully.  The filter holder should be tightened firmly to avoid leakage;

          A new flow record chart was set into the flow recorder;

          The programmable timer was set for the next sampling period of 24 hrs ! 1/2 hr;  

          The post-sampling filter papers were equilibrated at room temperature and relative humidity < 50% for at least 24 hours before weighing.

 

1- hour TSP Monitor:

 

          The following parameters of the TEOM model dust meters are regularly checked to ensure proper functionality:

 

        Mass concentration;

        Total mass;

        Frequency of the tapered element;

        Electrical noise;

        Main flow;

        Auxiliary flow.

 

Maintenance & Calibration

 

          The monitoring equipment and their accessories are maintained in good working conditions.

          Monitoring equipment is calibrated at monthly intervals.  Calibration details are shown in Appendix H.

 

 

2.6         Results And Observations

 

Dust monitoring was conducted as scheduled in the reporting month. All monitoring data and graphical presentation of the monitoring results are provided in Appendix E.  Key findings and observations are provided as below:

 

1-hour TSP

 

No exceedance of 1-hour TSP Action/Limit Level was recorded in the month.

 

24-hour TSP

 

No exceedance of 24-hour TSP Action/Limit Levels was reported in the month.

 

 

 


 

Figure 2.1           Location of Air Quality Monitoring Stations



3.             NOISE

 

 

3.1         Monitoring Requirements

 

Continuous noise alarm monitoring at Ash Lagoon/Ching Lam were carried out to calculate the noise contributed by the construction activities at the two critical NSR’s at Long Tsai Tsuen/Hung Shing Ye and the school within the village of Tai Wan San Tsuen.  The noise impact monitoring data for construction noise other than percussive piling were checked against the limit levels as specified in the EM&A Manual.  With the availability of the two construction noise permits on 2/4 and 24/4 respectively, impact monitoring for the construction work during the restricted hours was also carried out.  Section 5 presents the details of the construction noise permits.

 

As there were no activities for the construction of the transmission system, no manual noise measurement at the Pak Kok Tsui residences was carried out in the reporting month.  Appendix C shows the established Action/Limit Levels for noise.

 

 

3.2         Monitoring Locations

 

In accordance with the EM&A manual, the identified noise monitoring locations are listed in Table 3.1 and shown in Figure 3.1.

 

Table 3.1    Noise Monitoring Locations

 

Purpose of noise monitoring

Monitoring Location

Lamma Extension

Ash Lagoon

Lamma Extension

Ching Lam

 

 

3.3         Monitoring Equipment

 

The sound level meters used for noise monitoring complied with International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1).  The noise monitoring equipment used is shown in Table 3.2.

 

Table 3.2    Noise Monitoring Equipment

 

Equipment

Model

Sound level meter

Rion NA-27

Calibrator (IEC 60942 Class 1)

Rion NC-74


 

3.4         Monitoring Parameters, Frequency and Duration

 

Continuous noise alarm monitoring of A-weighted Leq levels was carried out at Ash Lagoon and Ching Lam.  The measurement duration and parameter of noise monitoring were presented in Table 3.3 as follows:

 

Table 3.3    Noise Monitoring Duration and Parameter

 

Location

Time Period

Frequency

Parameter

Ash Lagoon

 

Ching Lam

Daytime:

0700-1900 hrs on normal weekdays

 

Evening-time & holiday *:

0700-2300 hrs on holidays; and 1900-2300 hrs on all other days

 

Night-time *:

2300-0700 hrs of next day

Daytime:

30 minutes

 

 

Evening-time & holiday:

5 minutes

 

 

Night-time:

5 minutes

30-min LAeq

 

 

5-min LAeq

 

 

5-min LAeq

 

* Noise monitoring is only carried out after the CNP was effective 

 

3.5         Monitoring Procedures and Calibration Details

 

Monitoring Procedures

 

The measured noise levels (MNL's) were collected at the noise alarm monitoring stations at Ash Lagoon and Ching Lam.  The notional background noise levels (viz. baseline noise data at Ash Lagoon and Ching Lam) were applied to the corresponding MNL's in 30-min/5-min LAeq.

 

A wind speed sensor was installed at Station Building Rooftop.  The wind speed signal was used to determine whether the data from Ash Lagoon and Ching Lam noise alarm monitoring stations were affected.  The instantaneous data was discarded in case the instantaneous wind speed exceeded 10 m/s.  The 30-min/5-min LAeq was considered valid only if the amount of valid data was equal to or above 70%.

 

The Environmental Team, when calibrating the noise measuring equipment, recorded all observations around the monitoring stations, which might have affected the monitoring results.

 

 

Equipment Calibration

 

Monthly calibration of the noise measuring equipment was carried out.  Calibration details are shown in Appendix H.

 

The sound level meters and calibrators were verified by the manufacturer.  A copy of calibration certificates is shown in Appendix H.

 

 

3.6         Results & Observations

 

Continuous noise monitoring was conducted at the two monitoring stations at Ash Lagoon and Ching Lam.  All monitoring results and their graphical presentations are provided in Appendix F.

 

Based on monitoring results, four cases of noise limit level exceedances were estimated for Long Tsai Tsuen/Hung Shing Ye in the reporting month.  Details are summarised as follows:

 

 

Date

 

Time

 

Cause

 

Action taken

8/4/2001

13:05-13:15

Two limit level exceedances on noise at Long Tsai Tsuen/Hung Shing Ye was recorded  (measured noise level: 66 and 63dBA; Limit noise level: 60dBA).   As there was no dredging work on that day, the exceedances were not related to the construction work.  Hence no further action was required.

The construction contractor was informed of the limit level exceedances for investigation of the causes on 17/4/2001.  IEC and EPD were informed of the exceedances on 27/4/2001.

30/4/2001

05:10-05:15

One marginal limit level exceedance on noise at Long Tsai Tsuen/Hung Shing Ye was recorded  (measured noise level: 46dBA; Limit noise level: 45dBA).  After investigation, it is suspected that the limit level exceedance was caused by birds’ activities as birds were seen to gather around the noise monitoring station early in the morning.  Measures to deter birds are being devised. 

The construction contractor was informed of the limit level exceedance for investigation of the causes on 5/5/2001.  IEC and EPD were informed of the exceedance on 11/5/2001.

1/5/2001

06:40-06:45

One marginal limit level exceedance on noise at Long Tsai Tsuen/Hung Shing Ye was recorded  (measured noise level: 46dBA; Limit noise level: 45dBA).  After investigations, it is suspected that the limit level exceedance was caused by birds’ activities as birds were seen to gather around the noise monitoring station early in the morning.  Measures to deter birds are being devised. 

The construction contractor was informed of the limit level exceedance for investigation of the causes on 5/5/2001.  IEC and EPD were informed of the exceedance on 11/5/2001.

 

 


 

 

Figure 3.1    Location of Noise Monitoring Stations

 


4.             WATER QUALITY MONITORING

 

 

4.1         Monitoring Requirements

 

Marine water quality monitoring at the monitoring locations adjacent to the dredging and filling operations for Lamma Extension was carried out by a monitoring consultant, HKPC.  The purpose was to ensure that any deterioration of water quality could be detected and that timely action would be taken to rectify the situation.  The impact monitoring data were checked against the AL levels as set out in the Baseline Monitoring Report (Construction Phase).  As there were no activities for the laying of the gas pipeline in the reporting month, no water quality impact monitoring at the relevant stations was carried out. Appendix C shows the established Action/Limit Levels for water quality.

 

 

4.2         Monitoring Locations

 

A total of twelve water quality monitoring locations were selected. 7 Sensitive Receiver (SR) stations were chosen on the basis of their proximity to the dredging and filling operations, 5 Marine Control Stations (C) as recommended in the EIA were selected to facilitate comparison of the water quality of the SR stations with ambient water quality conditions. Table 4.1 describes the locations of these monitoring stations. Their locations are shown in Figure 4.1.

 

Table 4.1    Water Quality Monitoring Locations

 

Type

Monitoring Location

HK Metric Grid E

HK Metric Grid N

Sensitive Receiver Stations

SR1

830 224

811 528

SR2

829 004

810 903

SR3

829 194

(829 166)1

808 600

(808 592)1

SR4

830 119

808 650

SR5

830 386

807 189

SR6

829 977

805 758

SR7

829 566

804 545

Marine Control Stations

C1

830 542

813 492

C2

828 608

813 492

C3

826 776

809 978

C4

826 776

806 464

C5

830 440

802 186

1. Due to the construction programme, the monitoring location SR3 was slightly shifted since the monitoring on 16th April 2001.  EPD has verbally been informed of the shift of the monitoring location.

 

 

4.3         Monitoring Equipment

 

Table 4.2 summarizes the equipment used in the baseline water-quality monitoring programme.

 

Table 4.2    Water-Quality Monitoring Equipment

 

Equipment

Detection Limit

YSI 6820 Water Quality Monitor

Temperature: -5 to 50 0C; +/- 0.15 0C

Salinity: 0 to 70 ppt; +/- 0.2 ppt

Dissolved Oxygen: 0 to 200%; +/- 0.5%

0 to 20 mg/L; +/- 0.2 mg/L

Turbidity: 0 to 100 and 100 to 1000 NTU; +/- 5% of the range

pH: 0 to 14 units; +/- 0.2 units

Trimble NT200 GPS

Accuracy better than 3m

 

 

4.4         Monitoring Parameters, Frequency and Duration

 

Table 4.3 summarizes the monitoring parameters, frequencies and total duration of water quality monitoring. The monitoring schedule for reporting month is shown in Appendix D.

 

Table 4.3    Water Quality Monitoring Parameters and Frequency

 

Monitoring  Stations

Parameters

Frequency

No. of Depths

No. of Samples

Sensitive Receiver Stations

SR1, SR2, SR4, SR5, SR6 & SR7

 

Marine Control Stations

C1, C2, C3, C4 & C5

 

       Depth, m

       Temperature, oC

       Salinity, ppt

       DO, mg/L

       DO Saturation, %

       Turbidity, NTU

       SS, mg/L

       pH

       Total inorganic nitrogen, mg/L

       Un-ionised ammonia, mg/L

 

Three times per week

3

Surface,

Mid-Depth and Bottom

2

Mid-ebb and Mid-flood

 

For laboratory analysis of marine water samples collected at SR3, only SS parameter was measured.

 

 

4.5         Monitoring Procedures and Calibration Details

 

Monitoring Procedures

 

          The monitoring stations were accessed using survey boat to within 3m, guided by Differential Global Positioning System (DGPS). 

 

          The depth of the monitoring location was measured using depth meter in order to determine the sampling depths.  Afterwards, the water sampler was lowered into the water to the required depths of sampling.  Upon reaching the pre-determined depth, a messenger to activate the sampler was then released to travel down the wire. The water sample was sealed within the sampler before retrieving. 

 

          All in-situ measurements at each monitoring stations were taken at 3 water depths, where appropriate, namely 1m below water surface, mid-depth, and 1 meter from seabed, except where the water depth was less than 6m, the mid-depth measurement was omitted.  If the water depth was less than 3m, only the mid-depth position was monitored.

 

          At each measurement/sampling depth, two consecutive measurements were taken. The probes were retrieved out of the water after the first measurement and then redeployed for the second measurement.  Where the difference in the value between the first and the second readings of each set was more than 25% of the value of the first reading, the reading was discarded and further samplings were taken.

 

          The duplicate water samples for physical and chemical analysis were stored into a pre-labelled high-density polyethylene (HDPE) bottle pre-rinsed with the same water samples. The sample bottles were than packed in cool-box (cooled to 4oC without being frozen) and delivered to a HOKLAS Laboratory for analysis upon the completion of each round of sampling. 

 

          In addition, field information such as general meteorological conditions and any observations regarding any significant activities in the vicinity of each monitoring location were also recorded.  Major water pollution sources, if any, would be identified and recorded.

 

Equipment Calibration

 

The equipment deployed for in-situ measurement of marine water quality was calibrated before use.  The methodologies for the calibration follow the instruction manuals provided by the corresponding manufacturers.  The calibration records are shown in Appendix H.

 


Laboratory Analysis & QA/QC

 

The collected marine water samples were analyzed for Suspended Solids, Total Inorganic Nitrogen and Unionized Ammonia with methodologies as summarized in Table 4.4.

 

Table 4.4    Laboratory Analysis Methodologies of Marine Water Samples

 

Parameter

Method

Limit of Reporting (mg/L)

Suspended Solids

APHA 17 ed 2540 D

1.0

Total Inorganic Nitrogen

APHA 18 ed 4500 NO2 B & NO3 E + APHA 17ed 4500-NH3B, E

0.01

Ammoniacal Nitrogen

(Un-ionized Ammonia)

APHA 17 ed 4500-NH3 G

0.01

(Limit of Reporting for Ammoniacal Nitrogen) x degree of ionization

 

Note: The determination of unionized ammonia was based on the articles entitled “Aqueous Ammonia Equilibrium Calculation: Effect of pH and Temperature” and “Ionization of Ammonia in Seawater: Effects of Temperature, pH and Salinity” which was accepted by EPD.

 

In order to ensure that the laboratory analysis works were carried out properly, stringent QA/QC procedures (which includes the sample preparation as well as the subsequent instrumentation analysis) were followed.  According to the requirements as stipulated in the EM&A Manual, QA/QC requirements for laboratory testing include: 1) "Blind" duplicate samples analysis of 10% collected marine water samples; and 2) in-house QA/QC procedures of the testing laboratory (this includes the use of blank, batch duplicates, quality control samples and matrix spike recovery test).

 

 

Blind Duplicate:

 

In order to cross check the precision of the measurement results obtained from the laboratory analysis, “blind” duplicate samples of 10% of the collected marine water samples were analysed alongside the normal samples.  The sample codes for the “blind” duplicates were determined by the sampling team and are not identifiable by the laboratory.  The results of the “blind” duplicate samples are summarized in Appendix H.

 

In accordance with the QA/QC procedures of Environmental Management Laboratory of HKPC, QA/QC procedures shall be conducted for at least 5% of samples.  A total of 792 sets of samples (for Total Inorganic Nitrogen and Unionized Ammonia) and 864 sets of samples (for Suspended Solids analysis) were received during the marine monitoring period including both ebb and flood tides.  Therefore at least 5% laboratory blanks, batch duplicates, quality control samples and recovery tests for each parameter were conducted.  The acceptance criteria are outlined in each type of Quality Control data. 

 

 

Blank:

 

A laboratory blank is an analyte free matrix to which all reagents are added in the same volumes or proportions as used in the standard sample preparation to monitor contamination introduced in laboratory.  The acceptance criterion for laboratory blank in Environmental Management Division (EMD) Laboratory of HKPC stipulated in EMD Quality Manual is less than the detection limit.  All the laboratory blank values and acceptance criterion of the following testing parameter are summarized in Appendix H.    

 

               Suspended Solids

               Unionized Ammonia

               Total Inorganic Nitrogen

 

 

Batch Duplicate:

 

Batch duplicate is an intra-laboratory split sample randomly selected from the sample batch to monitor the method precision in a given matrix.  The acceptance limit of duplicate values of the following testing parameters and their duplicate results are summarized in Appendix H.

 

               Suspended Solids

               Unionized Ammonia

               Total Inorganic Nitrogen

 

 

Quality Control Sample:

 

The quality control sample is the analysis of material with a known concentration of contaminants to determine the accuracy of results in a given matrix.  The quality control samples are not applicable to all testing parameters due to the constraints of the testing parameters.  The quality control samples results for the following testing parameters are shown in Appendix H.

 

               Unionized Ammonia

               Total Inorganic Nitrogen

 

Quality control sample testing is not applicable to the testing of Suspended Solids.

 

 


Matrix Spike:

 

Matrix spike is an intra-laboratory split of a sample digested spiked with target known concentration analyte to determine method bias in a given matrix.  The matrix spike is applicable to the following tests:

 

               Unionized Ammonia

               Total Inorganic Nitrogen

 

Matrix spike testing is not applicable to testing of Suspended Solids.  The matrix spike samples results are shown in Appendix H.

 

 

The QA/QC results in Appendix H indicated that the laboratory analysis works of the collected marine water samples were properly carried out and the measurement results obtained were valid in accordance with the Hong Kong Laboratory Accreditation Scheme (HOKLAS) requirements.  On the other hand, the “blind” duplicate measurement results indicated that the precision of the measurements for Suspended Solids, Total Inorganic Nitrogen and Unionized Ammonia are in compliance with the HOKLAS requirements.

 

 

4.6         Results and Observations

 

Marine water monitoring was conducted as scheduled in the reporting month except the monitoring on 11th April 2001 which was cancelled due to adverse weather.  All monitoring data and graphical presentation of the monitoring results are provided in Appendix G.  Key findings and observations are provided in the following tables:

 

Summary of Exceedances in Dissolved Oxygen (Surface and Middle) in April 2001

Monitoring Dates

Number of Exceedances

Investigation Findings

(if any)

Action Level

Limit Level

2nd April

0

0

N. A.

4th April

0

0

N. A.

6th April

0

0

N. A.

9th April

0

0

N. A.

13th April

0

0

N. A.

16th April

0

0

N. A.

18th April

0

0

N. A.

20th April

0

0

N. A.

23rd April

0

0

N. A.

25th April

0

0

N. A.

27th April

0

0

N. A.

30th April

0

0

N. A.

 

 


Summary of Exceedances in Dissolved Oxygen (Bottom) in April 2001

Monitoring Dates

Number of Exceedances

Investigation Findings

(if any)

Action Level

Limit Level

2nd April

0

0

N. A.

4th April

0

0

N. A.

6th April

0

0

N. A.

9th April

0

0

N. A.

13th April

0

0

N. A.

16th April

0

0

N. A.

18th April

0

0

N. A.

20th April

0

0

N. A.

23rd April

0

0

N. A.

25th April

0

0

N. A.

27th April

0

0

N. A.

30th April

0

0

N. A.

 

 

Summary of Exceedances in Turbidity (Depth Average) in April 2001

Monitoring Dates

No. of Exceedances

Investigation Findings

(if any)

Action Level

Limit Level

2nd April

0

0

N. A.

4th April

0

0

N. A.

6th April

0

0

N. A.

9th April

0

0

N. A.

13th April

0

0

N. A.

16th April

0

0

N. A.

18th April

0

0

N. A.

20th April

0

0

N. A.

23rd April

0

0

N. A.

25th April

0

0

N. A.

27th April

0

0

N. A.

30th April

0

0

N. A.

 

 

Summary of Exceedances in Suspended Solids (Depth Average) in April 2001

Monitoring Dates

Number of Exceedances

Investigation Findings

(if any)

Action Level

Limit Level

2nd April

0

0

N. A.

4th April

0

0

N. A.

6th April

0

1 (SR1 at mid flood tide)

Not related to site activities since no dredging and reclamation works were carried out

9th April

0

0

N. A.

13th April

0

0

N. A.

16th April

0

0

N. A.

18th April

0

0

N. A.

20th April

0

0

N. A.

23rd April

0

0

N. A.

25th April

1 (SR1 at mid flood)

0

Not related to site activities since SR1 was located at the upstream of the study area during the sampling

27th April

0

0

N. A.

30th April

0

1 (SR1 at mid flood)

Not related to site activities since the results at SR2, located upstream of SR1, was much lower than the result at SR1 suggesting that the background fluctuation is significant

 


Summary of Exceedances in Unionized Ammonia (Depth Average) in April 2001

Monitoring Dates

Number of Exceedances

Investigation Findings

 (if any)

Action Level

Limit Level

2nd April

0

0

N. A.

4th April

1 (SR6 at mid ebb tide)

0

Not related to site activities since no dredging works were carried out

6th April

1 (SR2 at mid ebb tide)

0

Not related to site activities since no dredging works were carried out

9th April

0

0

N. A.

13th April

0

0

N. A.

16th April

0

0

N. A.

18th April

0

0

N. A.

20th April

0

0

N. A.

23rd April

5

 (SR1, SR2, SR5, SR7 during mid ebb;

SR2 during mid flood)

0

The exceedances at SR1 and SR2 during ebb tide were not related to site activities since they were located upstream of the site works activities during the sampling.

 

The exceedances at SR5 and SR7 during mid ebb tide were not related to site activities.  By reviewing the literature data of EPD in 1999, the range of SS in the vicinity of the said stations (i.e. SM5) was <0.001 to 0.003, therefore the elevated measurement results might be due to the background fluctuation of the study area.

 

For the elevated measurement result at SR2 during flood tide, the routine monitoring results on 25/4/01 at the flood tide was used for result confirmation purpose and it was below the Action Level.  Therefore, it is considered that the elevated measurement result at SR2 during flood tide might be due to the background fluctuation.

 

25th April

1

(SR2 at mid ebb)

0

The exceedance was not related to site activities. It was rainy during sampling and SR2 was located quite close to the shore.  Therefore, it would be expected that the water quality at SR2 was significantly affected by the surface runoff from the shore.

27th April

8 (SR1,SR4, SR5, SR6 & SR7 at mid ebb; (SR2, SR5 & SR6 at mid flood)

2 (SR2 at mid ebb; SR7 at mid flood)

Measurement results at control stations were notably high (some measurements even higher than the impact station results) indicating that the background concentrations were already high.  In addition, based on the site diary there was no significant increase in the magnitude of construction works at the site area.  On the other hand, as recorded from the AFCD that red tide occurred in HK waters on 25th April suggesting that the elevated measurement results might be due to the background fluctuation.  Taking the above into account, the said exceedances were considered not related to site activities.

30th April

7 (SR4, SR5, SR6 & SR7 during mid ebb; SR5, SR6 and SR7 during mid flood)

0

Measurement results at control stations were found to be higher than the impact stations results suggesting that the background concentration were high.  The said exceedances were considered not related to site activities.  However, it was found that the magnitude of exceedances have decreased as compared with the results on 27th April 2001.

 

 

Summary of Exceedances in Total Inorganic Nitrogen (Depth Average) in April 2001

Monitoring Dates

Number of Exceedances

Investigation Findings

(if any)

Action Level

Limit Level

2nd April

0

0

N. A.

4th April

0

0

N. A.

6th April

0

0

N. A.

9th April

1 (SR4 at mid flood)

1 (SR4 at mid ebb)

Not related to site activities since no dredging works were carried out

13th April

0

0

N. A.

16th April

0

0

N. A.

18th April

0

0

N. A.

20th April

0

0

N. A.

23rd April

0

0

N. A.

25th April

0

1 (SR2 at mid ebb)

The exceedance was not related to site activities. It was rainy during sampling and SR2 was located quite close to the shore.  Therefore, it would be expected that the water quality at SR2 was significantly affected by the surface runoff from the shore.

27th April

1 (SR4 at mid ebb)

9 (SR1, SR2, SR5, SR6 & SR7 during mid ebb; SR2, SR5, SR6 and SR7 during mid flood)

Measurement results at control stations were notably high (some measurements even higher than the impact station results) indicating that the background concentrations were already high.  In addition, based on the site diary there was no significant increase in the magnitude of construction works at the site area.  On the other hand, as recorded from the AFCD that red tide occurred in HK waters on 25th April 2001 suggesting that the elevated measurement results might be due to the background fluctuation.  Taking the above into account, the said exceedances were considered not related to site activities.

30th April

2 (SR2 & SR4 during mid ebb)

2 (SR5 & SR6 during mid ebb)

Measurement results at control stations were found to be higher than the impact stations results suggesting that the background concentration were high.  The said exceedances were considered not related to site activities.  However, it was found that the magnitude of exceedances have decreased as compared with the results on 27th April 2001.

 

As all of the above exceedances were not related to site activities, no further action need to be devised.  Nevertheless, EPD, IEC and the construction contractor have been informed of the exceedances accordingly as per the requirements of the EM&A Manual.

 

 


 

Figure 4.1    Location of Water Quality Monitoring Stations

 

 


5.             ENVIRONMENTAL AUDIT

 

 

5.1         Review of Environmental Monitoring Procedures

 

The environmental monitoring procedures were regularly reviewed by the Environmental Team.  No modification to the existing monitoring procedures was recommended.

 

 

5.2         Assessment of Environmental Monitoring Results

 

Monitoring results for Air Quality, Noise and Water Quality

 

The environmental monitoring results for Air Quality, Noise and Water Quality in April 2001 presented in sections 2,3 and 4 respectively are summarized in Table 5.1.

 

Table 5.1    Summary of AL Level Exceedances on Monitoring Parameters

 

Item

Parameter Monitored

Monitoring Period

No. of Exceedances In

Event/Action Plan Implementation Status and Results

Action Level

Limit

Level

Air

1

Ambient TSP

(24-hour)

02/04/01-30/04/01

0

0

 

2

Ambient TSP

(1-hour)

02/04/01-30/04/01

0

0

 

Noise

1

Noise level at the critical NSR’s predicted by the noise alarm monitoring system

02/04/01-30/04/01

0

4

The exceedances were considered not related to the construction site.  For details, please refer to section 3 of the report. 

2

Manual noise monitoring at the Pak Kok Tsui residences

02/04/01-30/04/01

NA

NA

Construction of transmission system not yet commenced.

Water

1

DO

(Surface & Middle)

02/04/01-30/04/01

0

0

 

2

DO (Bottom)

02/04/01-30/04/01

0

0

 

3

SS

02/04/01-30/04/01

1

2

The exceedances were considered not related to the construction site.  Please refer to section 4 of the report for details. 

4

Turbidity

02/04/01-30/04/01

0

0

 

5

NH3-N

02/04/01-30/04/01

23

2

The exceedances were considered not related to the construction site.   Please refer to section 4 of the report for details. 

6

TIN

02/04/01-30/04/01

4

13

The exceedances were considered not related to the construction site.  Please refer to section 4 of the report for details. 

 

Waste Management  Records

 

The estimated amounts of different types of waste generated in April 2001 are shown in Table 5.2.

 

Table 5.2    Estimated Amounts of Waste Generated in April 2001

 

Waste Type

Description

Estimated Amount (m3)

Dredged Materials

Marine Mud

214,132

Construction Waste

Concrete Waste, Used formwork

0

Excavated Materials

Rock and soil

0

General Refuse

Domestic wastes collected on site

1

 

The total bulk volume of dredged material was 214,132m3.  No filling took place.

 

 

5.3         Site Environmental Audit

 

EPD officials have inspected the construction site on 4th April 2001 and 20th April 2001.  They were generally satisfied with the environmental performance of the Project.  In addition to these, site audits were carried out by ET on a weekly basis to monitor environmental issues on the construction sites to ensure that all mitigation measures were implemented timely and properly.  The site conditions were generally satisfactory.  All required mitigation measures were implemented.  The weekly site inspection results are attached in Appendix J. 

 

5.4         Status of Environmental Licensing and Permitting

 

All permits/licenses obtained as of April 2001 are summarised in Table 5.3.

 


Table 5.3    Summary of Environmental Licensing and Permit Status

 

Description

Permit No.

Valid Period

highlights

Status

From

To

Varied Environmental Permit

EP-071/2000/A

22/12/00

-

The whole construction work sites

Valid

Construction Noise Permit

GW-UW0109-01

 

 

 

GW-UW0163-01

 

02/04/01

 

 

 

 

24/04/01

01/10/01

 

 

 

 

08/10/01

4 derrick barges, 4 dredger grabs and 6 tug boats for 0700 to 2300 & holiday

 

2 dredger barges and 1 tug boat for 2300 to 0700 next day

Valid

Dumping Permit

EP/MD/01-174

07/04/01

06/10/01

Dumping at South Cheung Chau Disposal Area

Valid

 

 

5.5         Implementation Status of Environmental Mitigation Measures

 

Mitigation measures detailed in the permits and the EM&A Manual (Construction Phase) are required to be implemented.  An updated summary of the Environmental Mitigation Implementation Schedule (EMIS) is presented in Appendix K.

 

 

5.6         Implementation Status of Action/Limit Plans

 

 

The Action/Event Plans for air quality, noise and water quality extracted from the EM&A Manual (Construction Phase) are presented in Appendix I.

 

As all the action/limit level exceedances were not related to the construction work, no further action can be devised.  Nevertheless, EPD, IEC and the construction contractor have been informed of the exceedances accordingly as per requirements of the EM&A Manual. 

 

 

5.7         Implementation Status of Environmental Complaint Handling Procedures

 

There was no complaint / enquiry on environmental issues received in April 2001.


Table 5.4    Environmental Complaints / Enquiries Received in April 2001

 

Case Reference /

Date, Time Received /

Date, Time Concerned

Descriptions /Actions Taken

Conclusion /

Status

 

Nil

 

 

N/A

 

N/A

 

 

Table 5.5    Outstanding Environmental Complaints / Enquiries Received Before

 

Case Reference /

Date, Time Received /

Date, Time Concerned

Descriptions /Actions Taken

Conclusion /

Status

 

Nil

 

 

N/A

 

N/A

 

 

 



6.             FUTURE KEY ISSUES

 

 

6.1         Status of Natural Gas supply

 

Based on current project schedule HEC anticipates there is no delay in the supply of natural gas.

 

6.2         Key Issues for the Coming Month

 

Key issues to be considered in the coming month include:

 

               Noise from the operating equipment and machinery on-site;

               Accumulation of waste materials on site.

 

The following mitigation measures are required:

 

Construction Noise Impact

               To follow up any exceedance caused by the construction works.

 

Construction Water Impact

               To avoid the debris floating/suspending in the sea which may probably be generated during filling works.

 

Construction Waste Management

               To check for any accumulation of waste materials or rubbish on site.

 

 

6.3         Monitoring Schedules for the Next 3 Months

 

The tentative environmental monitoring schedules for the next 3 months are shown in Appendix D.

 

 

6.4         Construction Program for the Next 3 Months

 

The tentative construction program for the next 3 months is shown in Appendix L.

 

 



7.             CONCLUSION

 

Environmental monitoring and site inspection were performed on schedule in the reporting month except one marine water quality monitoring which was cancelled on 11th April 2001 due to adverse weather.  All monitoring results were checked and reviewed.

 

No Action/Limit level exceedance on 1-hour and 24-hour TSP level was recorded in the reporting month.

 

A total of four cases of limit level exceedance on noise were recorded in the reporting month.  It is suspected that two of them were caused by birds’ activities.  As the limit level exceedances were not related to construction activities, no further action can be devised. 

 

A total of 45 cases of action/limit level exceedance on water quality parameters were recorded in the reporting month.  As the action/limit level exceedances were not related to construction activities, no further action can be devised. 

 

Environmental mitigation measures recommended in the EM&A manual for the dredging activities were implemented in the reporting month.  No environmental complaint was received in the reporting month.  No prosecution was received for this Project in the reporting period. 

 

The environmental performance of the Project was generally satisfactory.