3.1
In accordance with the Updated EM&A
Manual, impact 1-hour TSP and 24-hr TSP monitoring were conducted to monitor
the air quality for the Works Contracts. Appendix
B shows the established Action/Limit Levels for the air quality monitoring
works.
3.2
Impact 1-hour TSP monitoring was conducted
for at least three times every 6 days, while the impact 24-hour TSP monitoring
was conducted for at least once every 6 days at one air quality monitoring
station.
3.3
Impact air quality monitoring was conducted
at the monitoring stations under the Works Contracts, as shown in Figure 1 according to Table 1.1 of
Updated EM&A Manual. Table 3.1 describes
the location of the air quality monitoring station.
Table 3.1 Location for Air
Quality Monitoring Locations
|
EP No. |
Contract No. |
Monitoring Station |
Location |
|
EP-468/2013/A |
ND/2019/01 |
KTN-DMS4 |
Temporary Structure near Fanling Highway (near Pak Shek
Au) |
3.4
As the power supply for High Volume Sample
(HVS) for TSP monitoring at KTN-DMS 4 was rejected, direct reading dust meter
was used to measure both 1-hour and 24-hour average TSP levels:-
Ÿ
The proposal for alternative monitoring
equipment (i.e. direct reading dust meter) for TSP monitoring was approved by
EPD according to approved Baseline Air Quality Monitoring Report (KTN & FLN
NDA); and
Ÿ
Adopt same measurement methodology (i.e.
direct reading dust meter) as baseline monitoring for reliable comparison.
3.5
The proposed use of portable direct reading
dust meters was submitted to IEC and obtained agreement from the IEC as stated
in Section 2.4.5 of the Updated EM&A Manual.
3.6
HVS for 24-hr TSP monitoring will be adopted once
secured supply of electricity become available at KTN-DMS 4.
3.7
Table
3.2
summarizes the equipment used in the impact air monitoring programme.
Copies of calibration certificates are attached in Appendix C.
Table 3.2 Air Quality Monitoring Equipment
|
Monitoring Station |
Equipment |
Model and Make |
Quantity |
|
KTN-DMS4 |
Dust Monitor |
AEROCET-831 |
1 |
3.8
Meteorological information extracted from
“Hong Kong Observatory - Ta Kwu Ling Weather Station”
was proposed as the alternative method to obtain representative wind data. For
Ta Kwu Ling Weather Station, it is located nearby the
Project site and situated at approximately 15m above mean sea level. The
station’s wind data monitoring equipment is set above the existing ground ten
meters in compliance with the general setting up requirement. Furthermore, this
station also provides other meteorological information, such as the humidity,
rainfall, air pressure and temperature etc.
3.9
The general weather conditions (i.e. sunny,
cloudy or rainy) were recorded by the field staffs during the monitoring day.
3.10
Table 3.3 summarizes the
monitoring parameters and frequencies of impact dust monitoring during the Works
Contracts activities. The air quality monitoring schedule for the reporting
month is shown in Appendix D.
Table 3.3 Impact Dust Monitoring Parameters,
Frequency and Duration
|
Parameters |
Frequency |
|
1-hr TSP |
Three times/ 6 days |
|
24-hr TSP |
Once / 6 days |
1-hour and 24-hour TSP Air Quality Monitoring
Instrumentation
3.11 Direct reading
dust meter was deployed for the air quality monitoring as shown in Table 3.2.
3.12 The measuring
procedures of the dust meter are in accordance with the Manufacturer’s
Instruction Manual as follows:
(AEROCET-831)
• The dust meter is
placed at least 1.3 meters above ground.
• Remove the red
rubber cap from the AEROCET-831 inlet nozzle.
• Turn on the power
switch that is located on the right side of the AEROCET-831.
• On power up the
product intro screen is displayed for 3 seconds. The intro screen displays the
product name and firmware version.
• Then the main
counter screen will be displayed.
• Press the START
button. Internal vacuum pump start running. After 1 minute the pump will stop
and the 0.5µm and 5µm channels will show the cumulative counts of particles
larger than 0.5µm and 5µm per cubic foot.
• The AEROCET-831 is
now checked out and ready for use.
• To switch off the
AEROCET-831 power to stop the measuring after sampling.
• Information such
as sampling date, time, and display value and site condition were recorded
during the monitoring period.
Maintenance/Calibration
3.13 The following
maintenance/calibration was required
for the direct dust meters:
• Check and
calibrate the meter by HVS to check the validity and accuracy of the results
measured by direct reading method at 2-month intervals throughout all stages of
the air quality monitoring.
3.14 The monitoring
results for 1-hour TSP and 24-hour TSP are summarized in Table 3.4 and
3.5, respectively. Detailed monitoring results and graphical presentations
of 1-hour and 24-hour TSP monitoring results are shown in Appendix E.
Table 3.4 Summary
Table of 1-hour TSP Monitoring Results during the
Reporting Month
|
Monitoring
Station |
Concentration (µg/m3) |
Action Level, µg/m3 |
Limit Level, µg/m3 |
|
|
Average |
Range |
|||
|
KTN-DMS4 |
54.8 |
41.1 – 87.1 |
297 |
500 |
Table 3.5 Summary Table of
24-hour TSP Monitoring Results during the
Reporting Month
|
Monitoring
Station |
Concentration (µg/m3) |
Action Level, µg/m3 |
Limit Level, µg/m3 |
|
|
Average |
Range |
|||
|
KTN-DMS4 |
87.2 |
69.9 – 142.5 |
192 |
260 |
3.15 All 1-hour and
24-hour TSP monitoring was conducted as scheduled in the reporting month. No
Action/Limit Level exceedances were recorded.
3.16 According to our
field observations, the major dust source identified at the designated air
quality monitoring stations in the reporting month are shown in Table 3.6:
Table 3.6 Observation at Dust
Monitoring Stations
|
Monitoring Station |
Major Dust Source |
|
KTN-DMS4 |
Excavation works, Road traffic |
3.17 Should
project-related non-compliance of the criteria occur, action in accordance with
the Action Plan in Appendix I shall
be carried out.