3
ENVIRONMENTAL MONITORING
REQUIREMENTS
Monitoring Requirements
3.1.1
In accordance with the approved
EM&A Manual 1-hour and 24-hour Total Suspended Particulates (TSP) are
required to be conducted to monitor the construction dust impact. The established Action/Limit Levels for the
environmental monitoring works are presented in Appendix D1.
Monitoring Frequency and
Schedule
3.1.2
The monitoring parameters and
frequency are summarized in Table 3.1. The monitoring schedule for the reporting
period is presented in Appendix E.
Table 3.1 TSP Monitoring Parameter and Frequency
|
Parameters |
Duration / hour |
Frequency |
|
24-hour
TSP |
24 |
Once
Every Six Days |
|
1-hour
TSP |
1 |
Three
Times Every Six Days |
Monitoring Locations
3.1.3
For Phase 1 Contract, a total
of five air sensitive receivers were identified according to the EM&A
Manual. The air quality monitoring
stations, namely ASR1 and ASR2, had already commenced since the commencement of
the construction of the Phase 1 Contract.
For ASR3 (Site 10, Hoi Lai Estate), the construction works of Hoi Lai
Estate were substantially completed by end of November 2004 and occupied by
residents on 10th December 2004. Therefore, the air quality
monitoring was carried out at ASR3 since
3.1.4
The three monitoring stations
(ASR1, ASR2 and ASR3) are listed in Table 3.2 and are presented in Appendix F.
Table 3.2 TSP Monitoring Locations
|
Location I.D. |
Description |
|
ASR1 |
Lai Chi Kok Park Mei Foo Sun Chuen (at the roof of the toilet block) |
|
ASR2 |
DSD Pumping Station (in the proximity of Stonecutters Military Base) |
|
ASR3 |
Hoi Lai Estate Hoi Yin House
(roof, 40/F ) |
3.1.5
Wind data monitoring was
carried out at the area P1-SA9 for logging wind speed and wind direction.
3.1.6
Continuous 24-hour and 1-hour
TSP air quality monitoring was performed using a TE-5170 Tisch Environmental
Inc. High Volume Air Sampler (HVS), which was installed at the ASR1, ASR2 and
ASR3. The sampler composed of a motor, filter holder, flow controller and a
sampling inlet. Its performance
specification complies with that required by USEPA Standard Title 40, Code of
Federation Regulations Chapter 1 (Part 50).
3.1.7
Details of the monitoring equipment
are given in Table 3.3. A copy of the
calibration certificate for the HVS and wind data monitor are attached in Appendix G1 and Appendix G2 respectively.
Table 3.3 Air Quality
Monitoring Equipment
|
Equipment |
Model |
Qty. |
|
HVS |
TE-5170 Tisch Environmental Inc. |
3 |
|
Calibrator |
TE-5028A Tisch Environmental Inc. |
1 |
Monitoring Procedures and Calibration Details of HVS
3.1.8
Calibration Procedures -
Calibration procedures of HVS are as follows (calibration certificates are
presented in Appendix G1) :
i.
A certified orifice transfer
standard with a calibration curve was used for the calibration.
ii.
The transfer standard was
connected to the inlet of the sampler.
The orifice manometer was then connected to the orifice pressure
port. The manometer’s connecting tubing
was inspected to make sure that there are no leaks between the orifice unit and
the sampler.
iii.
The motor was then disconnected
from the flow controller and plugged directly to an AC power source.
iv.
A weather station has been
setup at the Site Office to measure and record the ambient temperature, Ta (K)
and the barometer pressure Pa (mmHg) during calculation.
v.
The sampler was allowed to run
for at least 2 minutes to re-establish the run temperature conditions. The pressure drop across the orifice and the
well-type manometer reading was recorded during calibration. The variable resistance was adjusted to
repeat recording for four different flow rates.
vi.
The best fit straight line was
determined by linear regression and the slope (m1), intercept (b1) and
correlation coefficient (r) are then determined.
3.1.9
Operating/Analytical Procedure
i.
The flow rate of the HVS was
set to about 1.1m3/min-1.7m3/min prior to commencement of
the dust sampling in accordance with the manufacturer's instruction to within
the range recommended in USEPA Standard Title 40, CFR Part 50.
ii.
The samplers was located such
that:
a. the filter was about 1.3 meters above ground.
b. it was greater than 20 meters away from trees.
c. it was separated from any obstacle by at least twice the height of
the obstacle protruding above the sampler.
d. it has unrestricted airflow 270° around the sampler.
iii.
Fiberglass filters were used
for TSP sampling (G810) [Note: these filters have a collection efficiency of
> 99% for particles of 0.3 mm diameter.
iv.
All filters were equilibrated
in the conditioning environment for 24 hours before weighing. The conditioning
environment has a temperature setting between 25°C and 30°C and should not vary
by more than ±3°C; the relative humidity was < 50% and should not vary by
more than ±5%.
v.
A new filter was placed with stamped number upward on a supporting
screen.
vi.
The filter was properly aligned
on the screen so that the gasket formed an air-tight seal on the outer edges of
the filter.
vii.
Shelter lid closed and catch
secured with the aluminum strip.
viii.
The sampler was then allowed to
run for at least 5 minutes to establish run-temperature conditions.
ix.
The flow indicator reading was
recorded and the sampler flow rate was determined.
x.
The programmable timer was set
and the starting sampling time, weather condition and the filter number was
recorded.
xi.
At the end of sampling, the
filter was transferred from the filter holder of the HVS to a sealable plastic
bag and sent to the HOKLAS accredited laboratory for weighing. The elapsed time was also recorded. A copy of
the HOKLAS Certificate is attached in Appendix G5.
xii.
Before weighing, all filters
were equilibrated in a desiccator for 24 hours with temperature of 25°C±3°C and
the relative humidity (RH) 50%±5%, preferably 40%.
3.1.10 Maintenance
i.
The high volume sampler and
their accessories were maintained in good working condition; include replacing
motor brushes routinely and checking electrical wiring to ensure continuous
power supply.
ii.
The high volume samplers were
calibrated at bi-monthly intervals using TE-5028A Tisch Environmental Inc.
Calibration Kit throughout all stages of the air quality monitoring.
3.1.11 The Event/Action Plan for Air Quality is presented in Appendix H1.
3.2.1
Noise monitoring was conducted
at three monitoring
stations to monitor the construction noise impact.
3.2.2
According to the field study,
the noise generated from the major roads (such as Route 3 highway and Container
Port Road) was noticeable at all noise monitoring stations and therefore the
major roads were considered as an influencing factor of the noise sensitive
receivers.
3.2.3
As the noise monitoring
stations are located at urban area and directly affected by this Influencing
Factor (IF), the Area Sensitivity Rating of the noise monitoring stations is
considered to be “C” according to the Table 1 of the Technical Memorandum on
Noise from Construction Work other than Percussive Piling under Noise Pollution
Control Ordinance.
3.2.4
The Action/Limit Levels for the
environmental monitoring works is established according to the EM&A manual
and the Technical Memorandum under Noise Pollution Control Ordinance and is
presented in Appendix D2.
Monitoring Frequency and Schedule
3.2.5
The monitoring schedule is
presented in Appendix E and the frequency and parameters of noise
measurement are summarized in Table 3.4.
Table 3.4 Noise Monitoring Frequency and Parameters
|
Time Period |
Duration / min. |
Parameters |
Frequency |
|
Daytime (0700 to 1900) |
30 (6 consecutive Leq(5min) in
average) |
Leq,
L90 & L10 |
Once
per week |
|
*Evening (1900 to 2300) |
5 |
Leq,
L90 & L10 |
Six
times per week |
|
*Night (2300 to 0700 next day) |
5 |
Leq,
L90 & L10 |
Four
times per week |
|
*Holiday (0700-1900 on holidays) |
5 |
Leq,
L90 & L10 |
Six
times per week |
* Restricted hour noise monitoring: to be
conducted only when there is construction work carried out under valid CNP.
3.2.6
For Phase 1 Contract, a total
of five noise sensitive receivers were identified according to the EM&A
Manual. The noise monitoring stations,
namely NSR1 and NSR2, had already commenced since the commencement of the
construction of the Phase 1 Contract.
For NSR3, the noise monitoring was carried out since 17th
December 2004. Two other potential
sensitive receivers were also identified at Site 6 and CDA site, but no
baseline monitoring was carried out at these sites as they are not occupied by
residents.
3.2.7
The three monitoring stations
(NSR1, NSR2 and NSR3) are detailed in Table 3.5 and presented in Appendix F.
Table 3.5 Location of the Noise Monitoring Stations
|
Location I.D. |
Description |
Type of measurement |
|
NSR1 |
Lai Chi Kok Park Mei Foo Sun Chuen (at the roof of the toilet block) |
Free
Field |
|
NSR2 |
DSD Pumping Station (in the proximity of Stonecutters Military Base) |
Free
Field |
|
NSR3 |
Hoi Lai Estate Hoi Yin House (roof, 40/F) |
Free
Field |
Monitoring
Equipment
3.2.8
Integrating Sound Level Meters
were used for noise monitoring which were Type 1 sound level meters capable of
giving a continuous readout of the noise level readings including equivalent
continuous sound pressure level (Leq) and percentile sound pressure
level (Lx). They comply with
International Electrotechnical Commission Publications 651:1979 (Type 1) and
804:1985 (Type 1). Also, a portable electronic wind speed indicator capable of
measuring wind speed in m/s was used to monitor the wind speed. Table
3.6 summarizes the noise monitoring equipment required.
Table 3.6 Noise Monitoring
Equipment
|
Equipment |
Model |
|
Integrating
Sound Level Meter |
SC-30, CESVA NL-31, Rion |
|
Calibrator |
CB-5, CESVA |
|
Portable Wind
Speed Indicator |
PWM2, Dwyer |
Monitoring Procedures and Calibration
Details
3.2.9
Field Monitoring
i.
The microphone of the Sound
Level Meter (with weatherproof kit) was mounted on a tripod at a height of 2m
above ground level.
ii.
For free field measurement, the
meter was positioned away from any nearby reflective surfaces.
iii.
AC power supply was checked to
ensure good functioning of the meter.
iv.
Parameters such as frequency
weighting, the time weighting and the measurement time were set as follows:
a.
frequency weighting : A
b.
time weighting : Fast
c.
time measurement : 30
minutes / 5 minutes
v.
Prior to and after each noise
measurement, the meter was calibrated using the Calibrator for 94 dB at 1000
Hz. If the difference in the calibration
level before and after measurement was more than 1 dB, the measurement would be
considered invalid and repeat of noise measurement would be required after
re-calibration or repair of the equipment.
vi.
The wind speed was frequently
checked with the portable wind meter.
vii.
At the end of the monitoring
period, the Leq, L90 and L10 were
recorded. In addition, site conditions
and noise sources were recorded on a standard record sheet.
viii.
Noise measurement was paused
during periods of high intrusive noise if possible and observation was recorded
when intrusive noise was not avoided.
ix.
Noise monitoring was cancelled
in the presence of fog, rain, and wind with steady speed exceeding 5 m/s, or
wind with gusts exceeding 10m/s.
3.2.10 Maintenance and Calibration
i.
The microphone head of the
sound level meter and calibrator were cleaned with a soft cloth at quarterly
intervals.
ii.
The meter was sent to the
supplier to check and calibrate yearly.
iii.
Calibration certificates are
presented in Appendix G4.
3.2.11
The Event/Action Plan for Noise
impact is presented in Appendix H2.