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 |
4 |
|
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 |
183.9 |
124.9 –
267.2 |
303 |
500 |
|
FLN -DMS3 |
153.6 |
81.6 –
263.6 |
301 |
500 |
|
KTN-DMS4 |
103.7 |
62.3 –
136.9 |
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 |
100.9 |
78.6 –
132.2 |
150 |
260 |
|
FLN -DMS3 |
96.4 |
51.0 –
143.0 |
165 |
260 |
|
KTN-DMS4 |
112.3 |
84.7 –
147.8 |
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, excavator,
tree felling |
|
FLN
-DMS3 |
Road traffic, dump truck |
|
KTN-DMS4 |
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.