2.1
Monitoring Requirement
In
accordance with the approved EM&A Manuals, 24-hour Total Suspended
Particulates (TSP) level at the designated air quality monitoring station is
required. Impact 24-hour TSP monitoring should be carried out at least once
every 6 days. In case of complaints, 1-hour TSP monitoring should be carried
out at least 3 times per 6 days when the highest dust impacts are likely to
occur. The Action and Limit Levels of the air quality monitoring are given in Appendix
C.
2.2
Monitoring Equipment
The
24-hour TSP air quality monitoring was performed using High Volume Air Samplers
(HVS) located at each of the designated monitoring station. Portable TSP
Monitors would be used in case of complaints for 1-hour TSP monitoring.
Table 2.1 summarizes the equipment used in air
quality monitoring.
2.3
Monitoring Methodology
2.3.1
24-hour TSP air quality monitoring
HVS
Installation
The
following guidelines were adopted during the installation of HVS:
n Sufficient support is
provided to secure the samplers against gusty wind.
n No two samplers are placed
less than 2 meters apart.
n The distance between the sampler
and an obstacle, such as buildings, is at least twice the height that the
obstacle protrudes above the sampler.
n A minimum of 2 meters of
separation from walls, parapets and penthouses is required for rooftop samples.
n A minimum of 2 meters
separation from any supporting structure, measured horizontally is required.
n No furnaces or incineration
flues are nearby.
n Airflow around the samplers
is unrestricted.
n The samplers are more than 20
meters from the drip line.
n Any wire fence and gate, to
protect the sampler, should not cause any obstruction during monitoring.
Filters
Preparation
Fiberglass
filters (provided by the HOKLAS accredited laboratory) shall be used (Note:
these filters have a collection efficiency of larger than 99% for particles of
0.3 µm diameter). A HOKLAS accredited laboratory (ALS Technichem (HK) Pty Ltd.)
is responsible for the preparation of 24-hr conditioned and pre-weighed filter
papers for monitoring team.
All
filters are equilibrated in the conditioning environment for 24 hours before
weighing. The conditioning environment temperature is around 25°C and not
variable by more than ±3°C; the relative humidity (RH) is < 50% and not
variable by more than ±5%. A convenient working RH is 40%.
Operating / Analytical Procedures
Operating
/ analytical procedures for the air quality monitoring are highlighted as
follows:
n Prior to the commencement of
the dust sampling, the flow rate of the HVS are properly set (between 0.6 m3/min
and 1.7 m3/min) in accordance with the EM&A manual. The flow rate
shall be indicated on the flow rate chart.
n The power supply shall be
checked to ensure the samplers worked properly.
n On sampling, the samplers
shall be operated for 5 minutes to establish thermal equilibrium before placing
any filter media at the designated air quality monitoring station.
n The filter holding frame is
then removed by loosening the four nuts and carefully a weighted and
conditioned filter is centered with the stamped number upwards, on a supporting
screen.
n The filter shall be aligned
on the screen so that the gasket formed an airtight seal on the outer edges of
the filter. Then the filter holding frame is tightened to the filter holder
with swing bolts. The applied pressure should be sufficient to avoid air
leakage at the edges.
n The shelter lid shall be
closed and secured with the aluminum strip.
n The timer is then programmed.
Information shall be 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).
n After sampling, the filter
shall be removed and sent to laboratory for weighing. The elapsed time is also
recorded.
n Before weighing, all filters
are equilibrated in a conditioning environment for 24 hours. The conditioning
environment temperature should be between 25°C and 30°C and not vary by more
than ±3°C; the relative humidity (RH) should be < 50% and not vary by more
than ±5%. A convenient working RH is 40%. Weighing results are returned to MCL
for further analysis of TSP concentrations collected by each filter.
2.3.2
1-hour TSP air quality monitoring
Operating / Analytical Procedures
The measuring procedures of the 1-hr dust meter
are in accordance with the Manufacturer’s instruction Manual as follows:
§ Pull
up the air sampling inlet cover
§ Change
the Mode 0 to BG once
§ Push
Start/Stop switch once
§ Turn
the knob to SENSI.ADJ and press it
§ Push
Start/Stop switch once
§ Return
the knob to the position MEASURE slowly
§ Push
the timer set switch to set measuring time
§ Remove
the cap and make a measurement
2.4
Maintenance / Calibration
2.4.1 24-hour
TSP air quality monitoring
The
following maintenance / calibration are required for the HVS:
n The high volume motors and
their accessories are properly maintained. Appropriate maintenance such as
routine motor brushes replacement and electrical wiring checking are made to
ensure that the equipments and necessary power supply are in good working
condition.
n All HVS shall be calibrated
(five point calibration) using Calibration Kit upon installation and thereafter
in every 3 months.
n A copy of the calibration
certificates for the HVS and calibrator are provided in
2.4.2 1-hour
TSP air quality monitoring
The portable
TSP monitor should be calibrated at 1 year intervals
2.5.1
According to the EM&A Manual, three air
quality monitoring locations, namely KTD1, KTD2 and KER1, are covered by this
Contract within the South Apron Area of Former Kai Tak Airport. The other two
air quality monitoring locations, which are identified in Cha Kwo Ling area,
are farther than 500m away from the site boundary and thus not covered by this
Contract. The monitoring works in Cha Kwo Ling area are covered by other Contract(s)
respectively.
2.5.2
According to the approved alternative baseline
air quality and noise monitoring locations (EPD reference: () in EP2/K19/A/21
pt.5), the original monitoring locations (KTD1, KTD2 and KER1) are proposed to
be replaced by alternative monitoring locations (KTD1a, KTD2a and KER1a) for
air quality monitoring.
2.5.3
According to the approved relocation of
monitoring location KER1a (EPD reference: () in EP2/K19/A/21 pt.5), the
monitoring location KER1a are proposed to be relocated by alternative
monitoring locations KER1b for air quality monitoring.
2.5.4
According to the approved relocation of
monitoring location KTD2a (EPD reference: () in EP2/K19/A/21 pt.6), the
monitoring location KTD2a are proposed to be relocated by alternative
monitoring locations KTD2b for air quality monitoring.
2.5.5
The most updated locations are summarized in Table 2.2
and shown in Figure 2.
2.6.1
The schedule of air quality monitoring in reporting
month is provided in Appendix E.
2.6.2
No Action / Limit
Level exceedance was recorded for 24-hr TSP at KTD1a, KTD2b and KER1b in the reporting month.
2.6.3
No complaint of air quality was received. Therefore,
no impact 1-hour TSP monitoring was conducted in the reporting month.
2.6.4
During the reporting month, major dust sources
including loading and unloading of C&D wastes, vehicles movement were
observed in the site. Non-project related construction activities at the nearby
construction site and road traffic along Shing Fung Road, Shing Cheong Road,
Cheung Yip Street and the Kwun Tong By-pass were observed. The above factors may affect the monitoring results.
2.6.5
The weather conditions during the monitoring are
provided in Appendix K.
2.6.6
The monitoring data of 24-hr TSP are summarized in Table 2.3. Detailed monitoring data are
presented in Appendix F.
2.6.7
The Event and Action Plan for air quality is given
in Appendix H.
2.7
Comparison of 24-hr TSP Monitoring Results
with EIA Predictions
2.7.1
The monitoring data of 24-hr TSP was compared with the
EIA predictions as summarized in Table 2.4.
2.7.2
The 24-hour TSP monitoring results at KTD1a and
KER1b were below the Predicted Maximum 24-hr TSP concentration in the approved
Environmental Impact Assessment (EIA) Report and no Action / Limit Level
exceedance was recorded in the reporting period.