In accordance with the recommendations of the EIA, mitigation measures have been proposed during the construction phase of the Project. Details of the mitigation measures are presented in Appendix E Implementation Schedule.
High volume sampler (HVS) in compliance with the following specifications shall be used for carrying out the 1-hr and 24-hr TSP monitoring:
a)
0.6-1.7 m3/min (20-60 SCFM) adjustable flow range;
b)
equipped with a timing/control device with +/- 5 minutes accuracy for 24 hours
operation;
c)
installed with elapsed-time meter with +/- 2 minutes accuracy for 24 hours
operation;
d)
capable of providing a minimum exposed area of 406 cm2 (63 in2);
e)
flow control accuracy: +/- 2.5% deviation over 24-hr sampling period;
f)
equipped with a shelter to protect
the filter and sampler;
g)
incorporated with an electronic mass flow rate controller or other equivalent
devices;
h)
equipped with a flow recorder for continuous monitoring;
i)
provided with a peaked roof inlet;
j)
incorporated with a manometer;
k)
able to hold and seal the filter paper to the sampler housing at horizontal
position;
l)
easy to change the filter; and
m)
capable of operating continuously for 24-hr period.
The HVSs shall be equipped with an electronic mass flow controller and be calibrated against a traceable standard at regular intervals. All the equipment, calibration kit, filter papers, etc. shall be clearly labelled.
Initial calibration of dust monitoring equipment shall be conducted upon installation and thereafter at bi-monthly intervals. The transfer standard shall be traceable to the internationally recognized primary standard and be calibrated annually. The calibration data shall be properly documented for future reference by the concerned parties such as the IEC. All the data shall be converted into standard temperature and pressure condition. The flow-rate of the sampler before and after the sampling exercise with the filter in position shall be verified to be constant and be recorded down in the data sheet in Appendix C.
If
the ET Leader proposes to use a direct reading dust meter to measure 1-hr TSP
levels, he shall submit sufficient information to the IEC to prove that the
instrument is capable of achieving a comparable result as that of the HVS and
may be used for the 1-hr sampling.
The instrument shall also be calibrated regularly, and the 1-hr sampling
shall be determined periodically by HVS to check the validity and accuracy of
the results measured by direct reading method.
Wind data monitoring equipment shall also be provided and set up at conspicuous
locations for logging wind speed and wind direction near to the dust monitoring
locations. The equipment
installation location shall be proposed by the ET Leader and agreed with the ER
in consultation with the IEC. For
installation and operation of wind data monitoring equipment, the following
points shall be observed:
a)
the wind sensors shall be installed
on masts at an elevated level 10m above ground so that they are clear of
obstructions or turbulence caused by the buildings;
b)
the wind data shall be captured by a
data logger. The data recorded in the data logger
shall be downloaded periodically for analysis at least once
a month;
c)
the wind data monitoring equipment
shall be re-calibrated at least once every six months; and
d)
wind direction shall be divided into
16 sectors of 22.5 degrees each.
3.4
Laboratory Measurement/Analysis
A clean laboratory with constant temperature and humidity control, and equipped with necessary measuring and conditioning instruments, to handle the dust samples collected, shall be available for sample analysis, and equipment calibration and maintenance. The laboratory shall be HOKLAS accredited or other internationally accredited laboratory.
If a site laboratory is set up or a non-HOKLAS accredited laboratory is hired for carrying out the laboratory analysis, the laboratory equipment shall be approved by the ER in consultation with the IEC.
Measurement
performed by the laboratory shall be demonstrated to the
satisfaction of the ER and the IEC.
IEC shall conduct regular audit to the measurement performed by the laboratory
to ensure the accuracy of measurement results.
The ET Leader shall provide the ER with one copy of the Title 40 of the
Code of Federal Regulations, Chapter 1 (Part 50),
Appendix B for his reference.
Filter paper of size 8"x10" shall be labelled before sampling. It shall be a clean filter paper with no pin holes, and shall be conditioned in a humidity controlled chamber for over 24-hr and be pre-weighed before use for the sampling.
After sampling, the filter paper loaded with dust shall be kept in a clean and tightly sealed plastic bag. The filter paper is then returned to the laboratory for reconditioning in the humidity controlled chamber followed by accurate weighing by an electronic balance with readout down to 0.1 mg. The balance shall be regularly calibrated against a traceable standard.
All the collected samples shall be kept in a good condition for 6 months before disposal.
The status and locations of dust sensitive receivers may change after issuing this manual. If such cases exist, the ET Leader shall propose updated monitoring locations and seek approval from ER and agreement from the IEC. When alternative monitoring locations are proposed, the following criteria, as far as practicable, shall be followed:
a)
at the site boundary or such
locations close to the major dust emission source;
b)
close to the sensitive receptors; and
c)
take into account the prevailing
meteorological conditions.
The ET Leader shall agree with the ER in
consultation with the IEC the position of the HVS for installation of the
monitoring equipment. When positioning the samplers, the following points shall
be noted:
a)
a horizontal platform with
appropriate support to secure the samplers against gusty wind shall be provided;
b)
no two samplers shall be placed less
than 2 metre apart;
c)
the distance between the sampler and
an obstacle, such as buildings, must be at least twice the height that the
obstacle protrudes above the sampler;
d)
a minimum of 2
metres
of separation from walls, parapets and penthouses is required for rooftop
samplers;
e)
a minimum of 2
metre
separation from any supporting structure, measured horizontally is required;
f)
no furnace or incinerator flue is
nearby;
g)
airflow around the sampler is
unrestricted;
h)
the sampler is more than 20 metres from the dripline;
i)
any wire fence and gate, to protect
the sampler, shall not cause any obstruction during monitoring;
j)
permission must be obtained to set up
the samplers and to obtain access to the monitoring stations; and
k) a secured supply of electricity is needed to operate the samplers.
The ET Leader shall carry out baseline monitoring at all of the designated monitoring locations for at least 14 consecutive days prior to the commissioning of the construction works to obtain daily 24-hr TSP samples. 1-hr sampling shall also be done at least 3 times per day while the highest dust impact is expected. Before commencing the baseline monitoring, the ET leader shall inform the IEC of the baseline monitoring programme such that the IEC can conduct on-site audit to ensure accuracy of the baseline monitoring results. During the baseline monitoring, there shall not be any construction or dust generation activities in the vicinity of the monitoring stations. In case the baseline monitoring cannot be carried out at the designated monitoring locations during the baseline monitoring period, the ET Leader shall carry out the monitoring at alternative locations which can effectively represent the baseline conditions at the impact monitoring locations. The alternative baseline monitoring locations shall be approved by the ER and agreed with the IEC.
In exceptional cases, when insufficient baseline monitoring data or questionable results are obtained, the ET Leader shall liaise with the IEC and EPD to agree on an appropriate set of data to be used as a baseline reference and submit to ER for approval.
Ambient
conditions may vary seasonally and shall be reviewed at three monthly intervals.
If the ET Leader considers that the ambient conditions have been changed and a
repeat of the baseline monitoring is required to be carried out for obtaining
the updated baseline levels, the monitoring shall be at times when the
contractor's activities are not generating dust, at least in the proximity of
the monitoring stations. Should
change in ambient conditions be determined, the baseline levels and, in turn,
the air quality criteria, shall be revised.
The revised baseline levels and air quality criteria shall be agreed with the
IEC and EPD.
3.6
Impact Monitoring
T
he ET Leader shall carry out impact monitoring during the course of the Works. For regular impact monitoring, the sampling frequency of at least once in every six-days, shall be strictly observed at all the monitoring stations for 24-hr TSP monitoring. For 1-hr TSP monitoring, the sampling frequency of at least three times in every six-days shall be undertaken when the highest dust impact occurs. Before commencing the baseline monitoring, the ET leader shall inform the IEC of the impact monitoring programme such that the IEC can conduct on-site audit to ensure accuracy of the impact monitoring results.
The specific time to start and stop the 24-hr TSP monitoring shall be clearly
defined for each location and be strictly followed by the field operator. In case of non-compliance with the air
quality criteria, more frequent monitoring exercise, as specified in the Action
Plan, shall be conducted within 24 hours after the result is obtained. This
additional monitoring shall be continued until the excessive dust emission or
the deterioration in air quality is rectified.
3.7
Event and Action Plan for Air
Quality
n addition to the dust monitoring, regular
site audits (at a frequency of not less than once every two weeks) are
recommended to ensure that appropriate dust control measures are implemented and
good site practices are adopted throughout the construction period.
Table 3.1
Action and Limit Levels for Air Quality Monitoring
|
Parameters |
Action |
Limit |
|
24 Hour TSP Level in
mg m-3 |
For
baseline level <200
mg m-3,
Action Level = (Baseline level * 1.3 + Limit Level/2); For baseline level >200
mg m-3,
Action Level = Limit Level |
260 |
|
1 Hour TSP Level in
mg m-3 |
For
baseline level <384
mg m-3,
Action Level = (Baseline level * 1.3 + Limit Level/2); For baseline level >384
mg m-3,
Action Level = Limit Level |
500 |
Table 3.2
Event and Action Plan for Air Quality
|
EVENT |
ACTION |
|||
|
ET |
IEC |
ER |
Contractor |
|
|
Action Level Exceedance for One Sample |
1.
Identify source(s) of impact;
2.
Inform the IEC and the ER;
3.
Repeat measurement to confirm findings;
4.
Increase monitoring frequency to daily
|
1.
Check monitoring data submitted by ET;
2.
Check Contractor’s working method |
1.
Notify Contractor |
1.
Rectify any unacceptable practice;
2.
Amend working methods if appropriate |
|
Action Level Exceedance for Two or More Consecutive Samples |
1.
Identify source(s) of impact;
2.
Inform the IEC and ER;
3.
Repeat measurement to confirm findings;
4.
Increase monitoring frequency to daily;
5.
Discuss with IEC and Contractor on remedial action
required;
6.
If exceedance continues, arrange meeting with IEC and ER;
7.
If exceedance stops, cease additional monitoring
|
1.
Checking monitoring data submitted by ET;
2.
Check Contractor’s working method;
3.
Discuss with ET and Contractor on possible remedial measures;
4.
Advise the ER on the effectiveness of the proposed remedial
measures;
5.
Supervisor implementation of remedial measures |
1.
Confirm receipt of notification of failure in writing;
2.
Notify Contractor;
3.
Ensure remedial measures properly implemented |
1.
Submit proposals for remedial actions to IEC within 3
working days of notification;
2.
Implement the agreed proposals;
3.
Amend proposal if appropriate |
|
Limit Level Exceedance for One Sample |
1.
Identify source(s) of impact;
2.
Inform the EPD and the ER;
3.
Repeat measurement to confirm findings;
4.
Increase monitoring frequency to daily;
5.
Assess effectiveness of Contractor’s remedial actions and
keep IEC, EPD and ER informed of results
|
1.
Check monitoring data submitted by ET;
2.
Check Contractor’s working method;
3.
Discuss with ET and Contractor on possible remedial
measures;
4.
Advise the ER on the effectiveness of the proposed remedial
measures;
5.
Supervise implementation of remedial measures |
1.
Confirm receipt of notification of failure in writing;
2.
Notify Contractor;
3.
Ensure remedial measures properly implemented |
1.
Take immediate action to avoid further exceedance;
2.
Submit proposals for remedial actions to IEC within 3
working days of notification;
3.
Implement the agreed proposals
4.
Amend proposal if appropriate |
|
Limit Level Exceedance for Two or More Consecutive Samples |
1.
Notify IEC, ER, Contractor and EPD;
2.
Identify source(s) of impact;
3.
Repeat measurement to confirm findings;
4.
Increase monitoring frequency to daily;
5.
Carry out analysis of Contractor’s working procedures to
determine possible mitigation to be implemented;
6.
Arrange meeting with IEC and ER to discuss the remedial
actions to be taken;
7.
Assess effectiveness of Contractor’s remedial action and
keep IEC, EPD and ER informed of the results;
8.
If exceedance stops, cease additional monitoring
|
1.
Discuss amongst ER, ET, and Contractor on the potential
remedial actions;
2.
Review Contractor’s remedial actions whenever necessary to
assure their effectiveness and advise the ER accordingly;
3.
Supervise the implementation of remedial measures |
1.
Confirm receipt of notification of failure in writing;
2.
Notify Contractor; 3. In consultation with the IEC, agree with the Contractor on the remedial measures to be implemented; 4. Ensure remedial measures properly implemented;
5.
If
exceedance continues, consider what portion of the work is
responsible and instruct the Contractor to stop that portion of work until
the exceedance is abated |
1.
Take immediate action to avoid further exceedance;
2.
Submit proposals for remedial actions to IEC within 3
working days of notification;
3.
Implement the agreed proposals
4.
Resubmit proposals if problem still not under control;
5.
Stop the relevant portion of works as determined by the ER
until the exceedance is abated |
