5.1
Air Quality Parameters
5.1.1A Monitoring and
audit of the Total Suspended Particulates (TSP) levels shall be carried
out by the ET to ensure that any deteriorating air quality could be readily
detected and timely action taken to rectify the situation.
5.1.1
5.1.2
One-hour
and 24-hour TSP levels should be measured to indicate the impacts of
construction dust on air quality. The 24-hour TSP levels shall be measured by
following the standard high volume sampling method as set out in the Title 40
of the Code of Federal Regulations, Chapter 1 (Part 50), Appendix B. Upon approval of the
IEC, 1-hour TSP levels can be measured by direct reading methods which are
capable of producing comparable results as that by the high volume sampling
method, to indicate short event impacts.
5.1.3
All relevant data including temperature, pressure,
weather conditions, elapsed- time meter reading for the start and stop of the
sampler, identification and weight of the filter paper, and any other local
atmospheric factors affecting or affected by site conditions, etc., shall be
recorded down in detail. A sample data sheet is shown in Appendix D.
5.2
Monitoring Equipment
5.2.1
High volume samplers (HVSs) complying with the
following specifications shall be used for carrying out the 1-hour and 24-hour
TSP monitoring:
a.
0.6
- 1.7 m3 per minute 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;
e.
flow
control accuracy: +/- 2.5% deviation over 24-hour 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.
easily
changeable filter; and
m.
capable of operating continuously
for a 24-hour period.
5.2.2
The ET is responsible for the provision,
installation, operation, maintenance, dismantle of the monitoring equipment. They
shall ensure that sufficient number of HVSs with an appropriate calibration kit
is available for carrying out the baseline monitoring, regular impact
monitoring and ad hoc monitoring. 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.
5.2.3
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 recognised
primary standard and be calibrated annually. The concern parties such as IEC
shall properly document the calibration data for future reference. All the data
should be converted into standard temperature and pressure condition.
5.2.4
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 in the data sheet as mentioned in Appendix D.
5.2.5
If the ET proposes to use a direct reading dust
meter to measure 1-hour TSP levels, he shall submit sufficient information to
the IEC to prove that the instrument is capable of achieving a comparable
result 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.
5.2.6
Wind data monitoring equipment shall also be
provided and set up set up for logging wind speed and wind direction near the
dust monitoring locations. The equipment installation location shall be
proposed by the ET and agreed with the IEC. For installation and operation of
wind data monitoring equipment, the following points shall be observed:
a.
The
wind sensors should be installed 10 m above ground so that they are clear of
obstructions or turbulence caused by buildings.
b.
The
wind data should be captured by a data logger. The data shall be downloaded for
analysis at least once a month.
c.
The
wind data monitoring equipment should be re-calibrated at least once every six months.
d.
Wind
direction should be divided into 16 sectors of 22.5 degrees each.
5.2.7
In exceptional situations, the ET may propose
alternative methods to obtain representative wind data upon approval from the
ER and agreement from the IEC.
5.3
Laboratory Measurement / Analysis
5.3.1
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 should be
HOKLAS accredited.
5.3.2
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 and the measurement procedures shall be
witnessed by the IEC. Any measurement performed by the laboratory shall be
demonstrated to the satisfaction of the ER and IEC. IEC shall regularly 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.
5.3.3
Filter paper of size 8" x 10" shall be
labelled before sampling. It shall be a clean filter paper with no pinholes,
and shall be conditioned in a humidity-controlled chamber for over 24-hours and
be pre-weighed before use for the sampling.
5.3.4
After sampling, the filter paper loaded with dust
shall be kept in a clean and tightly sealed plastic bag. The filter paper shall
then be 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.
5.3.5
All the
collected samples shall be kept in a good condition for 6 months before
disposal.
5.4
Monitoring Locations
5.4.1A Figure 5.1 shows the locations
of the proposed air quality monitoring station. The status and locations
of air quality 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. The air quality
monitoring locations are described in Table 5.1.
5.4.1
5.4.2A When alternative air quality monitoring locations are
proposed, the proposed site should, as far as practicable:
a.
Be
at the site boundary or such locations close to the major dust emission source;
b.
Be
close to the sensitive receptors; and
c.
Take
into account the prevailing meteorological conditions.
5.4.2
5.4.3
The
ET shall agree with the ER in consultation with the IEC on the position of the HVS
for the 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 should be provided;
b.
No
two samplers should be placed less than 2 meters 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 meters separation from walls, parapets and penthouses is required
for rooftop samplers;
e.
A
minimum of 2 meters 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 meters from the dripline;
i.
Any
wire fence and gate, to protect the sampler, should 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.
5.4.4
The ENPO may, depending on site conditions and
monitoring results, decide whether additional monitoring locations shall be
included or any monitoring locations could be removed / relocated during any
stage of the construction phase.
5.5
Baseline Monitoring for Fugitive Dust
5.5.1
Baseline monitoring shall be carried out at all of
the designated monitoring locations (see Table
5.1) for at least 14 consecutive days prior to the
commissioning of major construction works to obtain daily 24-hour TSP samples.
The selected baseline monitoring stations should reflect baseline conditions at
the impact stations. One-hour sampling should also be done at least 3 times per
day while the highest dust impact is expected.
5.5.2
During the baseline monitoring, there should not be
any major construction or dust generation activities in the vicinity of the
monitoring stations. Before commencing baseline monitoring, the ET shall inform
the IEC of the baseline monitoring programme such that, if required, the ER can
conduct on-site audit to ensure accuracy of the baseline monitoring results.
5.5.3
In case the baseline monitoring cannot be carried
out at the designated monitoring locations, the ET Leader shall carry out the
monitoring at alternative locations that 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.
5.5.4
In exceptional cases, when insufficient baseline
monitoring data or questionable results are obtained, the ET 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.
5.5.5
Ambient conditions may vary seasonally and shall be
reviewed once every three months. When the ambient conditions have changed and
a repeat of the baseline monitoring is required to be carried out for obtaining
the updated baseline levels, the monitoring should 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, should be revised. The
revised baseline levels and air quality criteria should be agreed with the IEC
and EPD.
5.5.6
5.5.6A The
baseline monitoring was undertaken for the Project between September and
November 2011 under Agreement CE No.35/2011 (EP) ¡§Baseline Environmental
Monitoring for Hong Kong¡VZhuhai-Macao Bridge Hong Kong Projects ¡V
Investigation¡¨ prior to commencement of construction of the Project. The
baseline monitoring results obtained under Agreement CE No.35/2011 (EP) will be
adopted for this Contract.
5.6
Impact Monitoring for Fugitive Dust
5.6.1
The ET shall carry out impact monitoring during the
entire construction period. For
regular impact monitoring, the sampling frequency of at least once in every 6
days, shall be strictly observed at all the monitoring stations for 24-hour TSP
monitoring. For 1-hour TSP monitoring, the sampling frequency of at least 3
times in every 6 days should be undertaken when the highest dust impact occurs.
Before commencing impact monitoring, the ET shall inform the IEC of the impact
monitoring programme such that the IEC can conduct on-site audit to ensure
accuracy of the monitoring results.
5.6.2
The specific time to start and stop the 24-hour TSP
monitoring shall be clearly defined for each location and be strictly followed
by the ET.
5.6.3
In case of non-compliance with the air quality
criteria, more frequent monitoring, as specified in the Action Plan in the
following section, shall be conducted within the specified timeframe after the
result is obtained. This additional monitoring shall be continued until the
excessive dust emission or the deterioration in air quality is rectified, and
agreed with the ER and the IEC.
5.7
Action / Limit Levels
5.7.1A The baseline monitoring results form the basis for
determining the air quality criteria for the impact monitoring. The ET shall
compare the impact monitoring results with air quality criteria set up for
24-hour TSP and 1-hour TSP. Table 5.2 shows
the air quality criteria, namely Action and Limit levels to be used.
5.8
Event and Action Plan
5.8.1
Should non-compliance of the air quality criteria
occur, actions in accordance with the Action Plan in Table
5.3 shall be carried out.
5.9
Mitigation Measures
5.9.1A The
approved EIA Report has recommended dust control measures including 8
times of watering per day. During the operation of the barging facilities, good
site practices such as road surface paving, dust enclosures, wheels wash
facilities would be implemented to reduce the generation of dust.
5.9.1
5.9.2
All
the proposed mitigation measures are summarised in the Environmental Mitigation
Implementation Schedule (EMIS) in Appendix B.
5.1A
5.2A
5.3A
5.4A
5.5A
5.6A
5.7A
5.8A
5.9A
5.10A
Reporting of
Monitoring Data to ENPO
5.10
5.10.1
5.10.1A The Assignment, which involves multiple
construction contracts, would be constructed concurrently with other major infrastructures
such as the HKLR and TMCLKL. These interface projects will be overviewed by the
ENPO. The ENPO will also oversee and coordinate the cumulative environmental
issues arising from the concurrent projects.
5.10.2
5.10.2A To facilitate the ENPO to evaluate environmental
impacts and investigate complaints, the ET Leaders shall provide the impact air
quality monitoring results within one week after the monitoring event. If the
1-hour TSP is measured by direct reading, the results shall be submitted to ENPO
in the next working day. The ET Leader shall follow ENPO's requirements on the
data submission format and procedures as per the current ET's practice and
enable rapid response by all concerned parties.