2.1
In this section, the requirements, methodology, equipment, monitoring
locations, criteria and protocols for the monitoring and audit of air quality
impact during the construction phase and operation phase of the Project are
presented.
2.2
The objectives of the air quality monitoring during construction phase
are:
·
to identify the extent of construction dust impact on sensitive
receivers;
·
to determine the effectiveness of mitigation measures in controlling
fugitive dust emission from activities during the construction phase;
·
to audit the compliance of the Contractor with regard to dust control,
contract conditions and the relevant dust impact criteria;
·
to recommend further mitigation measures if found to be necessary; and
·
to comply with Action and Limit (A/L) Levels for air quality as defined
in this Manual.
2.3
As identified in the EIA report, the Project would not cause any adverse
operational air quality impacts.
However, it is proposed to conduct odour monitoring to confirm the
effectiveness of the deodourizing unit once TM54SPS is in operation.
2.4
The ambient air quality criteria to be monitored and assessed are:
·
The Hong Kong Air Quality Objectives (AQOs) for TSP, 24-hour TSP levels
of
·
1-hour TSP limit of
·
5 odour units based on averaging time of 5 seconds or equivalent H2S
concentration of 2.5 ppb.
2.5
These levels are not to be exceeded at Air Sensitive Receivers (ASRs).
2.6
Monitoring and audit of the TSP levels shall be carried out by the ET to
detect any deteriorating air quality and to take timely action to rectify such
situation.
Construction
Phase
2.7
1-hour and 24-hour TSP levels shall 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 United States Code of
Federal Regulations, Chapter 1 (Part 50), Appendix B. Upon agreement from the ER and the IEC, 1-hour TSP levels can be
measured by direct reading methods to indicate short event impacts.
2.8
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, other local atmospheric factors
affecting or affected by site conditions and work progress of the concerned
site etc. shall be recorded in detail.
A sample data record sheet based on the one presented in the EM&A Guidelines for Development Projects
in Hong Kong, is shown in Appendix B. The ET Leader may modify the data record sheet for this EM&A
programme, of which the format should be agreed by the ER and the IEC.
High
Volume Sampler
2.9
High volume sampler (HVS) in compliance with the following
specifications shall be used for carrying out the 1-hour and 24-hour
monitoring:
·
0.6 -
·
equipped with a timing / control device with ± 5 minutes accuracy for 24
hours operation;
·
installed with elapsed-time meter with ± 2 minutes accuracy for 24 hours
operation;
·
capable of providing a minimum exposed area of
·
flow control accuracy: ± 2.5%
deviation over 24-hour sampling period;
·
equipped with a shelter to protect the filter and sampler;
·
incorporated with an electronic mass flow rate controller or other
equivalent devices;
·
equipped with a flow recorder for continuous monitoring;
·
provided with a peaked roof inlet;
·
incorporated with a manometer;
·
able to hold and seal the filter paper to the sampler housing at
horizontal position;
·
easy to change the filter;
·
capable of operating continuously for 24-hour period.
2.10
The ET shall be responsible for the provision of the monitoring
equipment. He shall provide sufficient number of HVSs with appropriate
calibration kit for carrying out the baseline, regular impacts 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.
2.11
Initial calibration of the dust monitoring equipment shall be conducted
upon installation and prior to commissioning, and at bi-monthly intervals
subsequently. The transfer standard
shall be traceable to the internationally recognised 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.
2.12
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 on the
data sheet as shown in Appendix B.
Portable
Dust Meter
2.13
If the ET proposes to use a direct reading dust meter to measure 1-hour
TSP levels, he shall submit sufficient information to the ER and the IEC to
prove that the instrument is capable of achieving a comparable result as that
of the HVS before it may be used for the monitoring works. The instrument shall also be calibrated
regularly, and the 1-hour sampling shall be determined periodically by HVS to
check the validity and accuracy of the results measured by direct reading
method.
Wind
Velocity Logger
2.14
Wind data monitoring equipment shall also be provided by the ET 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 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:
(i)
The wind sensors shall be installed
(ii)
The wind data shall be captured by a data logger. The data shall be downloaded for analysis at
least once a month;
(iii)
The wind data monitoring equipment shall be re-calibrated at least once
every six months;
(iv)
Wind direction should be divided into 16 sectors of 22.5 degrees each.
2.15
In exceptional situations, the ET may propose alternative methods to
obtain representative wind data upon approval from the ER and agreement from
the IEC.
Laboratory
Measurement / Analysis
2.16
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.
2.17
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 IEC. Measurement performed by the laboratory shall be demonstrated
to the satisfaction of the IEC.
2.18
The IEC shall conduct regular audit of the measurement performed by the
laboratory so as to ensure the accuracy of measurement results. The ET shall
provide the ER and the IEC with one copy of the Title 40 of the Code of Federal
Regulations, Chapter 1 (Part 50), Appendix B for their reference.
2.19
Filter paper of size 8"x10" 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-hour and be pre-weighed before use
for the sampling.
2.20
After sampling, the filter paper loaded with dust shall be kept in a
clean and tightly sealed 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 a readout down to 0.1mg. The
balance shall be regularly calibrated against a traceable standard.
2.21
All the collected samples shall be kept in a good condition for 6 months
before disposal.
Operation
Phase
2.22
Hydrogen sulphide (H2S) is one of the main components of
odour emissions. Since ambient H2S concentration can be readily
monitored at the ASRs, it can serve as a surrogate indicator for sewage
odours. Prior to the commissioning of
TM54SPS, H2S sampling at the selected Air Sensitive Receivers (ASRs)
shall be conducted simultaneously to establish the averaged baseline H2S
concentrations conditions at each measurement position at ASRs. The
baseline H2S concentrations at ASRs are used to establish the action
level to gauge the operating conditions of TM54SPS.
2.23
During commissioning of TM54SPS, simultaneous measurements of H2S
concentrations at source and at the selected ASRs are required. This is
to indicate whether the odour concentration would be higher or lower than the
baseline condition, and within the odour criteria at the ASRs. The odour level
at sources and meteorological data shall be obtained as reference information
for the analysis of the exceedance event.
Hydrogen
Sulphide Monitoring
2.24
H2S
concentrations shall be measured by portable H2S analyser, type
Jerome 631-X H2S, or equivalent. The analyser shall be able to
measuring H2S concentration in the range of 1 ppb to 50 ppm, with
resolution of 1 ppb. The analyzer operates within a temperature range of
0 to 40oC, at an air flowrate of
2.25
During the sampling period, meteorological data including temperature,
wind speed and direction shall be obtained from the nearest Hong Kong
Observatory’s Tuen Mun Weather Station.
Odour
Complaint Registration
2.26
It is proposed to establish a complaint registration system to handle
the odour complaint case. The operator
of the TM54SPS in future can have their compliant registration system and would
not be limited to the below proposed complaint registration system.
2.27
In the event when an odour complaint is received at the TM54SPS,
operator shall liaise with the complainant and a Complaint Registration Form
shall be completed. The Complaint Registration Form is to record detailed information
regarding the odour complaint and hence, facilitates efficient investigation
work. The registration form shall contain, but not be limited to the following
information:
·
Location of where the odour nuisance occurred, including whether the
odour was experienced indoors or outdoors;
·
Date and time of the complaint and the nuisance event;
·
Description of the complaint, i.e. the type and characteristics of the
odour; and an indication of the odour strength (highly offensive / offensive /
slightly offensive / just continuously detectable /intermittently detectable);
and
·
Name and contact information of the complainant.
2.28
This information shall be obtained by the plant engineer or his
representative(s) of the TM54SPS when the complaint is received. The Odour
Complaint Register is recommended to be kept at the TM54SPS. The Complaint Registration Form is shown in Appendix C for reference.
2.29
In addition, it is recommended to obtain the following information:
·
Meteorological conditions from the Hong Kong Observatory’s Tuen Mun
Weather Station (including temperature, wind speed, relative humidity) at the
time of the complaint; and
·
Whether any abnormal operations were being carried out at the TM54SPS at
the time the nuisance occurred.
Construction
Phase
2.30
The locations of the proposed air quality monitoring stations are shown
in Figure 2.1. The selected dust
monitoring stations as listed in Table 2.1 below are the existing
sensitive receivers located closest to the Project.
Table 2.1 Proposed Dust Monitoring Station During Construction Phase
|
Station |
Location |
|
A5 |
|
2.31
The status and locations of the air quality sensitive receivers may
change after issuing this Manual. The
ET shall propose updated monitoring locations and seek approval from EPD, and
agreement from the ER and the IEC before baseline monitoring commences.
2.32
When alternative monitoring locations are proposed, the following
criteria, as far as practicable, shall be followed:
(i)
at the site boundary or such locations close to the major dust emission
source;
(ii)
close to the air sensitive receivers;
(iii)
proper position/sitting and orientation of the monitoring equipment; and
(iv)
take into account the prevailing meteorological conditions.
2.33
The ET shall agree with the ER on the position of the HVS for
installation of the monitoring equipment.
When positioning the samplers, the following points shall be noted:
(i)
a horizontal platform with appropriate support to secure the samplers
against gusty wind shall be provided;
(ii)
no two samplers shall be placed less than 2 metres apart;
(iii)
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;
(iv)
a minimum of 2 metres of separation from walls, parapets and penthouses
is required for rooftop samplers;
(v)
a minimum of 2 metres of separation from any supporting structure,
measured horizontally is required;
(vi)
no furnace or incinerator flue is nearby;
(vii)
airflow around the sampler is unrestricted;
(viii)
the sampler is more than 20 metres from the dripline;
(ix)
any wire fence and gate, to protect the sampler, shall not cause any
obstruction during monitoring;
(x)
permission must be obtained to set up the samplers and to obtain access
to the monitoring stations; and
(xi)
a secured supply of electricity is needed to operate the samplers.
Operation
Phase
2.34
Odour monitoring and audit should be conducted by ET and IEC
respectively. Five Air Sensitive
Receivers (ASRs) have been identified for odour monitoring as shown in Table 2.2 and illustrated in Figure 2.1. H2S measurements
shall be taken at the sources and outside the premises of the identified
ASRs. The level for odour monitoring
shall be discussed and agreed with the DSD and EPD.
Table 2.2 Proposed Odour Monitoring Station During Operation Phase
|
Planned
Secondary School |
|
|
A5 |
|
2.35
Odour monitoring shall be taken at the exhaust vent pipe from
deodourizing unit to obtain the H2S concentrations at source. The selected locations are shown in Figure
2.1 and listed in Table 2.2. The
monitoring shall be taken at a height of predicted worst level of the receivers
in the EIA (i.e.
Construction
Phase
2.36
Baseline monitoring shall be carried out to determine the ambient 1-hour
and 24‑hour TSP levels at the monitoring locations prior to the
commencement of the Project works.
During the baseline monitoring, there shall not be any construction or
dust generating activities in the vicinity of the monitoring stations. The baseline monitoring will provide data
for the determination of the appropriate Action levels with the Limit levels
set against statutory or otherwise agreed limits.
2.37
Before commencing the baseline monitoring, the ET 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.
2.38
Baseline monitoring shall be carried out 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-hour TSP samples. One-hour sampling shall also be done at
least 3 times per day. Baseline
monitoring shall be carried out under typical weather conditions. General meteorological conditions (wind
speed, direction and precipitation) and notes regarding any significant
adjacent dust producing sources shall also be recorded throughout the baseline
monitoring period.
2.39
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 location
shall be approved by the ER and agreed with the IEC.
2.40
In exceptional cases, when insufficient baseline monitoring data or
questionable results are obtained, the ET Leader shall liaise with the ER, the
IEC and EPD to agree on an appropriate set of data to be used as a baseline
reference and submit to the ER and the IEC for agreement and EPD for approval.
2.41
Baseline checking of ambient TSP levels shall be carried out every three
months at each monitoring location, when no dusty works activities are in operation. If the ET considers that significant changes
in the ambient conditions have arisen, a repeat of the baseline monitoring may
be carried out to update the baseline levels. The revised baseline levels, in
turn, the air quality criteria, shall be agreed with the ER, EPD and the IEC.
Operation
Phase
2.42
One year prior to the commissioning of TM54SPS, a programme to monitor
concentrations of hydrogen sulphide (H2S) at the selected ASRs shall
be undertaken by the ET. Before
commencing the baseline monitoring, the ET shall submit the baseline monitoring
programme to the IEC for agreement.
2.43
The measured results of H2S at ASRs will serve as the
baseline data set prior to the commissioning of TM54SPS. These will be compared with the results
obtained during the impact monitoring stage.
2.44
In addition, the meteorological conditions from the nearest Hong Kong
Observatory’s Tuen Mun Weather Station (including temperature, wind speed,
relative humidity) shall be obtained
during baseline monitoring.
2.45
A 15-min H2S concentration should be measured every 3 hours
for duration of 24 hours at the monitoring locations. The purpose of sampling
in 3-hour intervals and to cover duration of a whole day is to capture the
different atmospheric conditions at different time periods. If, due to
insufficient monitoring equipment or monitoring personnel, monitoring can be
spread to 3 to 4 consecutive days as long as the different monitoring periods
and each of monitoring locations are covered.
2.46
The baseline monitoring events shall be carried out every three months
at the same locations within the year before TM54SPSis commissioned.
2.47
In order to gauge the most recent baseline condition before TM54SPS is
operational, the last baseline monitoring event should be assigned at a time of
1 to 2 weeks before the actual commissioning of TM54SPS.
Construction
Phase
2.48
The ET shall carry out impact monitoring during the construction phase
of the Project. For regular impact monitoring,
a sampling frequency of at least once in every six-days shall be strictly
observed at all of the monitoring stations for 24-hour TSP monitoring. For 1-hour TSP monitoring, the sampling
frequency of at least three times in every six days shall be undertaken when
the highest dust impact occurs.
2.49
Before commencing the 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 impact monitoring results.
2.50
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 field
operator.
2.51
In case of non-compliance with the air quality criteria, more frequent
monitoring, as specified in the Event and Action Plan in Table 2.3, shall be
conducted within the 24 hours after the non-compliance is known. This additional monitoring shall be
continued until the excessive dust emission or the deterioration in air quality
is rectified.
Operation
Phase
2.52
H2S measurements shall be conducted by the ET at the same
monitoring stations and levels as in the baseline period, using portable H2S
analyser, type Jerome 631-X H2S, or equivalent. The analyser shall be able to measure H2S
concentration in the range of 1 ppb to 50 ppm, with resolution of 1 ppb. Pairwise monitoring at ASRs and at source
should be carried out simultaneously. However, as the variation of odour
concentration at sources should be less significant, timing of sampling or
monitoring within TM54SPS should be more flexible so as to accommodate the
available resources for the monitoring programme.
2.53
The H2S monitoring programme shall be conducted in the first
year upon commissioning of TM54SPS. The
H2S monitoring shall be conducted every three months for the first
year of operation for TM54SPS. The
first H2S monitoring shall be conducted within one month, after the
operation of TM54SPS. Subsequent H2S
monitoring shall be conducted at the 4th, 7th and 10th month. If all monitoring results are below the
limit levels, the impact monitoring would be ceased. If the monitoring results of detected odour monitoring
concentration at any ASR is higher than the limit levels due to operation of
theTM54SPS, the odour monitoring shall be extended until the odour
concentration at the ASR in consecutive 2 times are below the limit levels
(once for 3 months). The operational
phase H2S monitoring programme is summarised in Table 2.3. The data sheet for H2S monitoring during
operational phase is provided in Appendix
B.
Table 2.3 Operational Phase H2S
Monitoring Programme
|
Sampling
duration |
Frequency |
|
24 hours |
Once
every three months for the first year after operation of TM54SPS If the results of any detected
odour concentration at any ASR is higher than the limit level due to
operation of TM54SPS, the odour monitoring programme shall be extended until
the odour concentration at the ASR in consecutive 2 times are below the limit
levels (once for 3 months). |
2.54
A 15-min integrated sample shall be collected every 3 hours for duration
of 24 hours at the monitoring stations. Monitoring shall not be conducted on
rainy days. Hourly meteorological conditions (temperature, wind speed & direction)
shall be recorded throughout the monitoring period.
2.55
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 1-hour and 24-hour TSP.
Table 2.4 shows the air quality criteria, namely Action and Limit
levels to be used. Should
non-compliance of the air quality criteria occur, action in accordance with the
Event and Action Plan in Table 2.5 and Table 2.6 shall be carried out.
Table 2.4 Action and Limit Levels for Air Quality
|
Parameter |
Action Level (1) |
Limit Level |
|
24-hour TSP |
BL £ 200 mg m-3, BL > 200 mg m-3, |
260 mg m-3 |
|
1-hour TSP |
BL £ 384 mg m-3, BL > |
500 mg m-3 |
|
H2S (at ASRs
only) |
·
BL £
1.92 ppb, AL = (BL * 1.3 + LL)/2 ·
BL > 1.92 ppb, AL = LL |
2.5 ppb |
|
Incidents of odour complaints |
Any incidence of odour complaint received through
the Odour Complaint Register |
Two
or more complaints through the Odour Complaint Register within three months |
Note: (1) BL = Baseline
level,
Table 2.5 Event and Action Plan for Air Quality (Dust)
|
EVENT |
ACTION |
|||
|
ET |
IEC |
ER |
CONTRACTOR |
|
|
Action level being exceeded by one sampling |
1. Identify source and
investigate the causes of exceedance; 2. Inform Contactor, IEC
and ER; 3. Repeat measurement to
confirm finding. |
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 being exceeded by two or more consecutive sampling |
1. Identify source and
investigate the causes of exceedance; 2. Inform Contractor, IEC
and ER; 3. Increase monitoring
frequency to daily; 4. Discuss with IEC and
Contractor on remedial actions required; 5. Assess the effectiveness
of Contractor’s remedial actions; 6. If exceedance continues,
arrange meeting with IEC and ER; 7. If exceedance stops,
cease additional monitoring. |
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; |
1. Confirm receipt of
notification of exceedance in writing; 2. Notify Contractor; 3. In consolidation with
the IEC, agree with the Contractor on the remedial measures to be
implemented; 4. Supervise implementation
of remedial measures; 5. Conduct meeting with ET
and IEC if exceedance continues. |
1. Discuss with ET and IEC
on proper remedial actions; 2. Submit proposals for
remedial actions to ER and IEC within three working days of notification; 3. Implement the agreed
proposals; 4. Amend proposal if
appropriate. |
|
Limit level being exceeded
by one sampling |
1. Identify source and investigate the causes
of exceedance; 2. Inform Contractor, IEC, ER, and EPD; 3. Repeat measurement to confirm finding; 5. Assess effectiveness of Contractor’s
remedial actions and keep EPD, IEC and ER informed of the 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. |
1. Confirm receipt of
notification of exceedance in writing; 2. Notify Contractor; 3. In consolidation with
the IEC, agree with the Contractor on the remedial measures to be
implemented; 4. Supervise implementation
of remedial measures; 5. Conduct meeting with ET
and IEC if exceedance continues. |
1. Take immediate action to
avoid further exceedance; 2. Discuss with ET and IEC
on proper remedial actions; 3. Submit proposals for
remedial actions to ER and IEC within three working days of notification; 4. Implement the agreed
proposals. |
|
Limit level being exceeded by
two or more consecutive sampling |
1. Notify IEC, ER,
Contractor and EPD; 2. Repeat measurement to
confirm findings; 3. Carry out analysis of
Contractor’s working procedures to identify source and investigate the causes
of exceedance; 4. Increase monitoring
frequency to daily; 5. Arrange meeting with
IEC, ER and Contractor to discuss the remedial actions to be taken; 6. Assess effectiveness of
Contractor’s remedial actions and keep EPD, IEC and ER informed of the
results; 7. If exceedance stops,
cease additional monitoring. |
1. Check monitoring data
submitted by ET; 2. Check Contractor’s
working method; 3. Discuss amongst ER, ET,
and Contractor on the potential remedial actions; 4. Review Contractor’s
remedial actions whenever necessary to assure their effectiveness and advise
the ER accordingly. |
1. Confirm receipt of
notification of exceedance in writing; 2. Notify Contractor; 3. In consolidation with
the IEC, agree with the Contractor on the remedial measures to be
implemented; 4. Supervise implementation
of remedial measures; 5. If exceedance continues,
consider stopping the Contractor to continue working on that portion of work
which causes the exceedance until the exceedance is abated. |
1. Take immediate action to avoid further
exceedance; 2. Discuss with ET, ER and IEC on proper
remedial actions; 3. Submit proposals for remedial actions to
IEC within three working days of notification; 4. Implement the agreed proposals; 5. Submit further remedial actions if problem
still not under control; 6. Stop the relevant portion of works as
instructed by the ER until the exceedance is abated. |
Table 2.6 Event/Action Plan for Air Quality Monitoring (Operational Phase)
|
EVENT |
ACTION |
||
|
ET |
IEC |
ER
(DSD) |
|
|
Exceedance of Action level |
1. Identify source/ reason
of exceedance; 2. Inform IEC and ER(DSD); 3. Carry
out investigation to identify the source/reason of exceedance or complaints.
Investigation shall be completed within 1 week and advise the findings to IEC
and DSD; 4. Repeat measurement to
confirm finding after rectification work. |
1. Check with ET and
ER(DSD) on the operating activities and implementation of odour mitigation
measures; 2. Discuss with ER(DSD) on
the possible remedial actions; 3. Advise the ER(DSD) on
the effectiveness of the proposed remedial measures; 4. Supervise implementation
of remedial measures. |
1. Confirm receipt of
notification of exceedance in writing; 2. Rectify
any unacceptable practice; 3. Amend
working methods as required; 4. Implement
amended working methods. |
|
Exceedance of Limit level |
1. Notify IEC, ER(DSD) and
EPD; 2. Identify source of
odour; 3. Increase monitoring
frequency; 4. Carry
out investigation to identify the source/reason of exceedance. Investigation
shall be completed within 1 week and advise the findings to IEC and ER(DSD); 5. Arrange meeting with IEC
and ER to discuss the remedial actions to be taken; 6. Assess effectiveness of
the remedial actions and keep IEC, EPD and ER(DSD) informed of the results. |
1. Check with ET and
ER(DSD) on the operating activities and implementation of odour mitigation
measures; 2. Review the proposed
remedial actions whenever necessary to assure their effectiveness and advise
the ER(DSD) accordingly; 3. Supervise implementation
of remedial measures. |
1. Confirm receipt of
notification of exceedance in writing; 2. Rectify
any unacceptable practice and amend working methods as required; 3. Formulate
remedial actions and inform ET and IEC; 4. Ensure
amended working methods and remedial actions properly implemented; 5. If
exceedance continues, consider what portion of the work is responsible and
stop that portion of work until the exceedance is abated. |
Note: (*) The
role of DSD SP / E&MP would be started upon commencement of the Project and
ceased one year after the commissioning of TM54SPS.
Construction
Phase
2.56
Mitigation measures for dust control have been recommended in the EIA
Report. The Contractor shall be
responsible for the design and implementation of these measures.
2.57
To comply with the guideline level and AQO at the ASRs, the good site
practices and mitigation measures stipulated in the Air Pollution Control (Construction Dust) Regulation should be
implemented to minimize construction dust impact. A number of practical measures are listed below:
·
Skip hoist for material transport
should be totally enclosed by impervious sheeting;
·
Vehicle washing facilities should
be provided at every vehicle exit point;
·
The area where vehicle washing
takes place and the section of the road between the washing facilities and the
exit point should be paved with concrete, bituminous materials or hardcore;
·
Where a site boundary adjoins a
road, streets or other areas accessible to the public, hoarding of not less
than 2.4 m high from ground level should be provided along the entire length
except for a site entrance or exit;
·
Use of regular watering, with
complete coverage, to reduce dust emissions from exposed site surfaces and
unpaved roads, particularly during dry weather;
·
Side enclosure and covering of
any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to
frequent usage, watering shall be applied to aggregate fines;
·
Open stockpiles shall be avoided
or covered. Where possible, prevent
placing dusty material storage piles near ASRs;
·
Tarpaulin covering of all dusty
vehicle loads transported to, from and between site locations;
·
Every stock of more than 20 bags
of cement should be covered entirely by impervious sheeting placed in an area
sheltered on the top and the 3 sides;
·
Every vehicle should be washed to
remove any dusty materials from its body and wheels before leaving the
construction sites; and
·
Instigation of an environmental
monitoring and auditing program to monitor the construction process in order to
enforce controls and modify method of work if dusty conditions arise.
2.58
The implementation schedule for the recommended air quality impact
mitigation measures during construction phase is presented in Appendix A.
Operation
Phase
2.59
It is recommended that the air ventilated from the wet wells and screen
chambers should be treated by deodorization unit (granular activated carbon)
with 90% odour removal efficiency before discharge to the atmosphere. All the treated air would be emitted from
the exhaust vent of the ventilation fan.
A standby deodourization unit (90% odour removal efficiency) would be
provided to cater for breakdown and maintenance of the duty deodourization
unit.
2.60
The following odour precautionary measures should be implemented during
operation of TM54SPS:
·
The
entire pumping station; especially wet wells and screening collection areas
should be enclosed in a building structure;
·
Discharge
point of the odour removal system should be directed away from the adjacent
sensitive uses as shown in Figure 2.1 and the exhaust air should be at a
vertical upward flow direction;
·
Screened
material from the TM54SPS should be stored in a covered container;
·
The
transportation of screened material during maintenance should be transported in
an enclosed type vehicle and disposed off on the same working day;
·
Checking
and maintenance of the odour removal system should be implemented at least once
every half year to maintain the removal efficiency; and
·
Odour
removal systems, e.g. activated carbon filters, should be provided to reduce
the odour emissions.