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
2.3
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
Two air quality monitoring stations were selected for 24-hr
and 1-hr TSP sampling at TKO 137.
2.5
The monitoring station TKO1 was relocated on 16 April 2006.
The first monitoring event at the new location was conducted on 18 April 2006. 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 |
2.6
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
2.7
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
2.8
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
2.9
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
2.10
Air suction inlet was normally closed
unless in operation. Regular cleaning of the air suction inlet was provided.
Wind Data
2.11
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
2.12
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.
2.13
Both HVS were calibrated on 6 April 2006. Calibration
details are provided in Appendix E.
1-hour TSP Monitoring
2.14
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.
2.15
The 1-hour TSP meter was calibrated on 18 June 2005
and the next calibration will be conducted by 17 June 2006.
2.16
In the reporting month, all the 1-hr and 24-hr TSP
monitoring events were carried out in accordance with the schedule, one 24-hour
TSP additional monitoring was conducted on 6 April 2006 at monitoring station
TKO1. The actual monitoring program for April 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 |
||
|
06/04 |
181.7 |
X |
203.0 |
X |
Regular |
|
12/04 |
210.2 |
X |
194.9 |
X |
Regular |
|
19/04 |
205.8 |
X |
214.4 |
X |
Regular |
|
29/04 |
189.4 |
X |
192.2 |
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 |
||
|
04/04 |
395.6 |
L |
283.3 |
L |
Regular |
|
06/04 |
119.5 |
X |
-- |
-- |
Additional |
|
11/04 |
62.8 |
X |
63.5 |
X |
Regular |
|
18/04 |
134.9 |
X |
137.3 |
X |
Regular |
|
28/04 |
51.7 |
X |
22.1 |
X |
Regular |
1.
L – limit level exceedance; A -
action level exceedance; X – not an exceedance
2.17
There was no exceedance in
1-hr TSP monitoring in the reporting month. Two limit level exceedances
in 24-hr TSP monitoring were recorded at TKO1 and TKO2 in the reporting month. According
to the ET’s on site observation, exceedances were
considered to be mainly caused by insufficient dampening along the haul road
and for the sorting activities inside the CWSF.
2.18
Due to high levels of 24-hr TSP recorded on 24 and 30
March 2006 (exceeding previous range from 69.3mg/m3 to 569.15mg/m3), additional
monitoring for 24-hr TSP at TKO1 was conducted on 6 April 2006. The Contractor
was advised to provide water sprinklers for all dumping, sorting and
transferring activities on site and for all haul roads inside the site. The
Contractor agreed to review the dust suppression measures on site.
2.19
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.
2.20
Wind data, including wind speed and wind direction, are
annexed in Appendix G.