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.