2.1
In
accordance with the Particular Specification of the Project, ET is required to
conduct 1-hr and 24-hr TSP monitoring at the temporary CWSF in TKO 137 during
the construction and operation periods to ensure the activities in the Project
does not generate dust which exceeds the acceptable level. Appendix C shows the
Action and Limit Levels for the environmental monitoring works.
2.2
High volume sampler (HVS - Model GS-2310 Accu-vol) complete
with the appropriate sampling inlets was installed for 24-hr TSP sampling. The
HVS is composed of a motor, a filter holder, a flow controller and a sampling
inlet and its performance specification complies with USEPA Standard Title 40,
Code of Federation Regulations Chapter 1 (Part 50 Appendix B). A portable dust
meter was used for the 1-hr TSP monitoring. Table 2.1 summarises the equipment
used.
Table 2.1 Air Quality Monitoring Equipment
|
Equipment |
Model |
|
HVS |
GS 2310
Accu-vol system |
|
Calibrator |
GMW 25 |
|
1-hour TSP Dust Meter |
Laser Dust
Monitor – Model LD-3 |
|
Calibrator – Dust Meter |
Rupprecht & Patashnick TEOM® |
Monitoring Parameter, Frequency and Schedule
2.3
The monitoring parameters and frequency are summarised in
Table 2.2. The monitoring schedule for the reporting period is shown in
Appendix D.
Table 2.2 Frequency of Air Quality Monitoring
|
Parameters |
Frequency |
|
24-hour TSP |
Once/week |
|
1-hour TSP |
Three times/week |
2.4
The location for the air quality monitoring station TKO2 is
provided in Table 2.3 and depicted in Figure 2.1.
Table 2.3 Air Quality Monitoring Stations
|
Station
ID |
Identity/Description |
|
TKO2 |
Combined Reception & Exit Office in Area B1 |
24-hour TSP Monitoring
Operating/Analytical Procedures
2.5
Operating/analytical procedures for the
operation of HVS are as follows:
·
The sampler
was placed on a horizontal platform with appropriate supporting structure such
that:
-
no
two samplers were placed less than 2 metres 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 metres separation from walls, parapets and penthouses was required
for the rooftop samplers.
-
a
minimum of 2 metres separation from any supporting structure, measured
horizontally was required.
-
airflow
around the sampler was unrestricted.
-
no
furnaces or incineration flues were operating near the sampler.
-
the
sampler was more than 20 metres from the dripline.
-
Any
wire fence and gate, to protect the sampler, should not cause any obstruction
during monitoring.
·
Prior
to the commencement of the dust sampling, the flow rate of the high volume
sampler was properly set (between 1.1 m3/min. and 1.4 m3/min.)
in accordance with the manufacturer's instruction to within the range
recommended in USEPA Standard Title 40, CFR Part 50.
·
For
TSP sampling, fibreglass filters (G810) were used [Note: these filters have a
collection efficiency of > 99% for particles of 0.3 mm diameter].
·
After
sampling, the filter was transferred from the filter holder of the HVS to a sealable
plastic bag and sent to the laboratory for weighing. The elapsed time was also
recorded.
·
Before
weighing, all filters were conditioned for 24 hours before weighing under
temperature of 25°C ±3°C and the relative humidity (RH) < 50% ±5%, preferably
40%.
·
All
measurement procedures in section 4.3 to 4.9 of the EM&A Manual were
followed during the reporting period.
Maintenance
2.6
Proper maintenance would be provided for
the HVS:
·
The
HVS motors and their accessories have been properly maintained. Appropriate
maintenance such as routine motor brushes replacement (time interval for
replacement is about 500 hours) and electrical wiring checking have been
conducted to ensure that the equipment and necessary power supply were in good
working condition.
1-hour TSP Monitoring
Measuring
Procedures
2.7
The sampler was placed with appropriate
supporting structure. The requirements of the location of the sampler were the
same as HVS and were presented in Section 2.5 of this report.
2.8
The measuring procedures of the 1-hour dust
meter were in accordance with the Manufacturer’s Instruction Manual as follows:
·
Set
POWER to “ON”, push
·
Push
the knob at MEASURE position.
·
Push
“O-ADJ” button. (Then meter’s indication is 0).
·
Push
the knob at SENSI ADJ position and set the meter’s indication to S value
described on the Test Report using the trimmer for SENSI ADJ.
·
Pull
out the knob and return it to MEASURE position.
·
Push
“START” button.
·
All
measurement procedures in section 4.3 to 4.9 of the approved EM&A Manual
were followed during the impact monitoring period.
Maintenance
2.9
Air suction inlet was normally closed
unless in operation. Regular cleaning of the air suction inlet was provided.
Wind Data
2.10
Historically, the meteorological data for Fill Bank operations
at the site was obtained from the in-situ wind station for TKO 137 under
previous contracts. Therefore, such practice would be maintained to ensure
consistence of meteorological data for the contract in the Fill Bank.
Calibration Details
24-hour TSP Monitoring
2.11
The
HVS was calibrated upon installation on site and prior to commissioning.
Subsequent calibration would be provided at 2-month intervals using GMW-25
Calibration Kit. The flow rate of the HVS with mass flow controller was
calibrated using an orifice calibrator. Five-point calibration was adopted.
2.12
The HVS was calibrated on 15 May 2007. Calibration details
are provided in Appendix E.
1-hour TSP Monitoring
2.13
The 1-hour TSP meters were checked at 3-month intervals to
confirm normal operation of the equipment and calibrated at 1-year interval
throughout all stages of the air quality impact monitoring.
2.14
The 1-hour TSP meters were
calibrated on 17 June 2006 and the next calibration will be conducted by 18
June 2007.
2.15
In the reporting month, all the 1-hr and 24-hr TSP
monitoring events were carried out in accordance with the schedule except for
one additional monitoring carried out on 16 May 2007.
2.16
The actual monitoring program for May 2007 is presented in Appendix
D. All monitoring data and graphical presentations of the monitoring results
are provided in Appendix F. Table 2.4 summarises the average of three 1-hr TSP
monitoring results and Table 2.5 lists out all the 24-hr TSP monitoring
results.
Table 2.4 Summary of 1-hr TSP Monitoring Results
|
Date |
TKO2 |
Monitoring Status |
|
|
Averaged 1-hr TSP (mg/m3) |
Exceedance1 |
||
|
02/05 |
147.1 |
X |
Regular |
|
08/05 |
109.6 |
X |
Regular |
|
19/05 |
124.2 |
X |
Regular |
|
25/05 |
97.4 |
X |
Regular |
|
31/05 |
98.7 |
X |
Regular |
1.
L – limit level exceedance; A - action level exceedance; X – not an
exceedance
Table 2.5 Summary of 24-hr TSP Monitoring Results
|
Date |
TKO2 |
Monitoring Status |
|
|
24-hr TSP (mg/m3) |
Exceedance1 |
||
|
07/05 |
275.9 |
L |
Regular |
|
16/05 |
234.5 |
X |
Additional
|
|
18/05 |
84.7 |
X |
Regular |
|
23/05 |
188.1 |
X |
Regular |
|
30/05 |
114.4 |
X |
Regular |
1.
L – limit level exceedance;
A - action level exceedance; X – not
an exceedance
2.17
There was one limit level exceedance
of 24-hour TSP recorded on 7 May 2007. The exceedance was concluded partially
related to the Project due to insufficient water spraying along the haul road
behind the site office. One additional monitoring was carried out 16 May 2007.
Water spraying had been provided to the haul road behind the Contractor’s site
office and no exceedance was recorded on 16 May 2007.
2.18
Besides the construction activities
inside the Project site, other potential dust sources included the dump truck
traffic and excavation activities inside the Fill Bank of TKO 137 and PBR2
CWSF.
2.19
Wind data, including wind speed and wind direction, are
annexed in Appendix G.