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 and Figure 2 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-473/2013/A |
ND/2019/03 |
FLN-DMS1[2] |
Scattered
Village Houses North of Proposed Potential Ecopark |
|
ND/2019/05 |
FLN-DMS3[3] |
House
near Tong Hang |
|
|
EP-466/2013 EP-467/2013/A EP-468/2013/A |
ND/2019/01 |
KTN-DMS4 |
Temporary
Structure near Fanling Highway (near Pak Shek Au) |
|
EP-468/2013/A |
ND/2019/03 |
Remark:
[1]: Noting that construction phase air
quality monitoring at the other proposed monitoring stations (e.g. planned),
where access is permitted, will be conducted during the relevant works
contract(s).
[2]: Since the distance between monitoring
station and site boundary of ND/2019/05 under EP-473/2013/A exceeds 500m. The
monitoring station is not applicable to ND/2019/05.
[3]: Since the distance between monitoring
station and site boundary of ND/2019/03 under EP-473/2013/A exceeds 500m. The
monitoring station is not applicable to ND/2019/03.
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 |
Manufacturer |
Model and Make |
Quantity |
|
KTN-DMS4 |
Dust Monitor (1-hour and 24-hour TSP) |
Met One Instruments |
AEROCET-831 |
3 |
|
FLN-DMS1 FLN-DMS3 |
Dust Monitor (1-hour TSP) |
|||
|
HVS Sampler (TSP) (24-hour TSP) |
Tisch |
TISCH Model: TE-5170 |
2 |
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.
24-hour TSP Air Quality Monitoring
Instrumentation
(TISCH Model: TE-5170)
3.14 High volume Samplers
(HVS) completed with appropriate sampling inlets were employed for 24-hour TSP
monitoring. Each sampler was
composed of a motor, a filter holder, a flow controller and a sampling inlet
and its performance specification complies with that required by USEPA Standard
Title 40, Code of Federation Regulations Chapter 1 (Part 50).
3.15 The following
guidelines were adopted during the installation of HVS:
• A horizontal
platform with appropriate support was provided to secure the samplers against
gusty wind.
• No two samplers
were placed less than 2 meters apart.
• The distance
between the sampler and an obstacle, such as buildings, was at least twice the
height that the obstacle protrudes above the sampler.
• A minimum of 2
meters of separation from walls, parapets and penthouses was required for
rooftop samples.
• A minimum of 2
meters separation from any supporting structure, measured horizontally was
required.
• No furnaces or
incineration flues were nearby.
• Airflow around the
sampler was unrestricted.
• The samplers were
more than 20 meters from the drip line.
• Any wire fence and
gate, to protect the sampler, should not cause any obstruction during
monitoring.
• Permission and access
to the monitoring stations have been obtained to set up the samplers; and
• A secured supply
of electricity was provided to operate the samplers.
Filters Preparation
3.16 Wellab Limited (HOKLAS
Registration No.083) is the HOKLAS accredited laboratory and responsible for
the preparation of 24-hr conditioned and pre-weighed filter papers for
monitoring team.
3.17 All filters were
equilibrated in the conditioning environment for 24 hours before weighing. The conditioning environment temperature
was around
Operating/Analytical
Procedures
3.18 Operating/analytical
procedures for the air quality monitoring were highlighted as follows:
• Prior to the
commencement of the dust sampling, the flow rate of the HVS was properly set
(between
• The power supply
was checked to ensure the sampler worked properly;
• On sampling, the
sampler was operated for 5 minutes to establish thermal equilibrium before
placing any filter media at the designated air quality monitoring station;
• The filter holding
frame was then removed by loosening the four nuts and carefully a weighted and conditioned
filter was centered with the stamped number upwards, on a supporting screen;
• The filter was
aligned on the screen so that the gasket formed an airtight seal on the outer
edges of the filter. Then the
filter holding frame was tightened to the filter holder with swing bolts. The applied pressure should be
sufficient to avoid air leakage at the edges;
• The shelter lid
was closed and secured with the aluminum strip;
• The timer was then
programmed. Information was
recorded on the record sheet, which included the starting time, the weather
condition and the filter number (the initial weight of the filter paper can be
found out by using the filter number);
• After sampling,
the filter was removed and kept in a clean and tightly sealed plastic bag. The
filter paper was then be returned to the HOKLAS laboratory (Wellab
Ltd.) for reconditioning in the humidity-controlled chamber followed by
accurate weighting by an electronic balance with a readout down to 0.1mg. The
elapsed time was also recorded; and
• Before weighing,
all filters were equilibrated in a conditioning environment for 24 hours. The
conditioning environment temperature should be between
Maintenance/Calibration
3.19 The following
maintenance/calibration was required for the HVS:
• The high volume
motors and their accessories were properly maintained. Appropriate maintenance
such as routine motor brushes replacement and electrical wiring checking were
made to ensure that the equipment and necessary power supply are in good
working condition; and
• All HVS were
calibrated (five point calibration) using Calibration Kit prior to the
commencement of the baseline monitoring and thereafter at bi-monthly intervals.
3.20 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 |
|||
|
FLN -DMS1 |
87.4 |
65.2-117.9 |
303 |
500 |
|
FLN -DMS3 |
85.7 |
43.1-135.9 |
301 |
500 |
|
KTN-DMS4 |
51.4 |
26.5-68.1 |
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 |
|||
|
FLN -DMS1 |
38.2 |
24.1-81.1 |
150 |
260 |
|
FLN -DMS3 |
41.4 |
21.6-86.6 |
165 |
260 |
|
KTN-DMS4 |
104.8 |
68.5-148.8 |
192 |
260 |
3.21 All 1-hour and
24-hour TSP monitoring was conducted as scheduled in the reporting month. No
Action/Limit Level exceedances were recorded.
3.22 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 |
|
FLN -DMS1 |
Road traffic |
|
FLN -DMS3 |
Road traffic |
|
KTN-DMS4 |
Excavation, Road traffic |
3.23 Should
project-related non-compliance of the criteria occur, action in accordance with
the Action Plan in Appendix J shall
be carried out.