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 samplers (HVS - Model GS-2310 Accu-vol) complete
with the appropriate sampling inlets were 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 |
Monitoring Parameter, Frequency and Schedule
2.1
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 |
2.2
Two air quality monitoring stations were selected for 24-hr
and 1-hr TSP sampling at TKO 137.
2.3
The locations for the air quality monitoring stations are
summarised in Table 2.3 and depicted in Figures 2.1.
Table
2.3 Air Quality Monitoring
Stations
|
Station ID |
Identity/Description |
|
TKO1 |
North Boundary
of the CWSF at TKO 137 in Area A |
|
TKO2 |
Combined
Reception & Exit Office in Area B1 |
2.4
During an ad-hoc site meeting with
the Engineer, IEC, Contractor and ET on 13 April 2006, ET proposed to cancel
the air quality monitoring station TKO1 due to its incapability in reflecting
the air quality impact arising from the Project upon the nearby sensitive
receiver (i.e.
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:
-
the
filter was at least 2.5 meters above ground.
-
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 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 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 of the approved EM&A Manual were
followed during the impact monitoring period.
Maintenance
2.8
Air suction inlet was normally closed
unless in operation. Regular cleaning of the air suction inlet was provided.
Wind Data
2.9
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
2.10
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.
2.11
Both HVS were calibrated on 6 April 2006. Calibration
details are provided in Appendix E.
1-hour TSP
Monitoring
2.12
The 1-hour TSP meter was 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.
2.13
The 1-hour TSP meter was calibrated
on 18 June 2005 and the next calibration will be conducted by 17 June 2006.
2.15
In the reporting month, all the 1-hr and 24-hr TSP
monitoring events were carried out in accordance with the schedule. The actual
monitoring program for May 2006 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 |
TKO1 |
TKO2 |
Monitoring
Status |
||
|
Averaged 1-hr TSP (mg/m3) |
Exceedance |
Averaged 1-hr TSP (mg/m3) |
Exceedance |
||
|
03/05 |
163.6 |
X |
168.1 |
X |
Regular |
|
11/05 |
163.5 |
X |
154.7 |
X |
Regular |
|
17/05 |
166.8 |
X |
155.8 |
X |
Regular |
|
23/05 |
150.1 |
X |
140.0 |
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 |
TKO1 |
TKO2 |
Monitoring
Status |
||
|
24-hr
TSP (mg/m3) |
Exceedance1 |
24-hr
TSP (mg/m3) |
Exceedance1 |
||
|
02/05 |
122.2 |
X |
121.6 |
X |
Regular |
|
10/05 |
180.4 |
X |
249.8 |
X |
Regular |
|
16/05 |
88.0 |
X |
150.1 |
X |
Regular |
|
22/05 |
160.6 |
X |
103.3 |
X |
Regular |
1.
L – limit level exceedance;
A - action level exceedance; X – not
an exceedance
2.16
There was no exceedance in 1-hr and
24-hr TSP monitoring in the reporting month.
2.17
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.
2.18
Wind data, including wind speed and wind direction, are
annexed in Appendix G.