2.
AIR QUALITY
2.1.1
In accordance with
the EM&A Manual, 1-hour Total Suspended Particulates (TSP) levels should be
measured at the designated air quality monitoring stations to ensure that any
deteriorating air quality could be readily detected
and timely action shall be undertaken to rectify such situation. Impact 1-hour
TSP monitoring was conducted for at least three times every 6 days when the
highest dust impact occurs.
2.2.1
A portable direct
reading dust meter was used to carry out the 1-hour TSP monitoring at the
designated monitoring stations.
2.2.2
Wind data
monitoring equipment is provided at the conspicuous locations for logging wind
speed and wind direction near to the dust monitoring locations. The equipment
installation location is agreed with the ER and the IEC.
2.2.3
The details of the air
quality monitoring equipment used are summarized in Table 2.1.
2.3
Monitoring Methodology for Direct Reading Dust Meter
2.3.1
SIBATA LD-5R
Digital Dust Indicator complete with appropriate sampling inlets are employed
for 1-hour TSP measurement.
Measuring
Procedures
a) Pulling up the air
sampling inlet cover
b) Changing the Mode 0 to
BG
c) Pressing Start/Stop
switch
d) Turning the knob to
SENSI.ADJ and press it
e) Pressing Start/Stop
switch again
f) Returning the knob to
the position MEASURE slowly
g) Pressing the timer set
switch to set measuring time
h) Removing the cap and start
the measurement
Equipment
Calibration
1-hour dust meter
should be calibrated at 1 year intervals. The
calibration certificates are presented in Appendix D.
2.4
Maintenance and Calibration for Direct Reading Dust Meter
2.4.1
ET shall submit
sufficient information to the IEC to prove that the instrument is capable of achieving comparable results to the HVS. The
instrument should also be calibrated regularly, and the 1-hour sampling shall
be determined periodically by the HVS to check the validity and accuracy of the
results measured by direct reading method. The calibration certificate for the
direct reading dust meter is provided in Appendix D.
2.5.1
In accordance with
the EM&A Manual, two air quality monitoring locations, namely AM1, AM2 are
covered under Contract No. SPW 07/2020 “Environmental Team for Construction of
Yuen Long Effluent Polishing Plant Stage 1”.
2.5.2
The most updated
locations are summarized in Table 2.2 and the locations of the air monitoring stations 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 1-hr TSP at AM1 and AM2.
2.6.3
No effect that
arose from the other special phenomena and work progress of the concerned site
was noted during the current monitoring month.
2.6.4
The weather and
meteorological conditions during the monitoring are provided in Appendix K.
2.6.5
The Air Quality Monitoring
Results of 1-hr TSP are summarized in Table
2.3. Detailed monitoring data are presented in Appendix F.
2.6.6
The Action and
Limit Levels for air quality monitoring have been set and are presented in Appendix
C.
2.6.7
The Event and
Action Plan for air quality is given in Appendix
H.
2.6.8
The wind data obtained from the on-site wind
station during the reporting period is provided in Appendix G.
2.7
Comparison of 1-hr TSP Monitoring Results with EIA Predictions
2.7.1
The monitoring data
of 1-hr TSP was compared with the EIA predictions as summarized in Table 2.4.
2.7.2
The 1-hr TSP
monitoring results at AM1 and AM2 were below the Predicted Maximum Hourly
Average TSP Concentration in the approved Environmental Impact Assessment (EIA)
Report.