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 |
6 |
|
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 |
111.0 |
71.4-150.2 |
303 |
500 |
|
FLN
-DMS3 |
123.1 |
75.0-210.9 |
301 |
500 |
|
KTN-DMS4 |
96.0 |
54.1-146.1 |
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 |
71.1 |
37.7-111.5 |
150 |
260 |
|
FLN
-DMS3 |
56.5 |
35.9-93.9 |
165 |
260 |
|
KTN-DMS4 |
115.7 |
80.8-161.2 |
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.