3.1
Monitoring Requirement
In
accordance with the approved EM&A Manuals, Leq
(30min) monitoring is conducted for at least once a week during the construction
phase between 0700 and 1900 on normal weekdays at the designated monitoring
locations.
3.2
Monitoring Equipment
The sound level meter used in noise monitoring will comply
with the International Electrotechnical Commission
Publication (IEC) 651:1979
(Type 1) and 804:1985 (Type 1) specifications as referred to in the Technical
Memorandum issued under the Noise Control Ordinance (NCO).
Sound level calibrator will be used for the on-site calibration of the
meter. This calibrator complies with the IEC Publication 942 (1988) Class 1 and
ANSI S1.40 - 1984. Noise measurements were only accepted to be valid if the
calibration levels from before and after the measurement agree to within 1.0dB.
Measurements shall be recorded to the nearest 0.1dB. This noise monitors
are programmed to measure A-weighted equivalent continuous sound pressure level
at 30-minute intervals between 0700 and 1900
on normal weekdays at least once a week when construction activities are
underway.
Table 3.1 summarizes the noise
monitoring equipment model being used for this project.
Table 3.1 Noise
Monitoring Equipment
|
Item |
Brand |
Model |
Equipment |
Serial Number |
|
1 |
Casella |
CEL-63X Series |
Integrating Sound Level Meter |
1057034 |
|
2 |
Casella |
CEL-633A Series |
Integrating Sound Level Meter |
0873599 |
|
3 |
Casella |
CL63X Series |
Integrating Sound Level Meter |
4637931 |
|
4 |
Casella |
CEL-120/1 |
Calibrator |
0255083 |
|
5 |
Casella |
CEL-120/1 |
Calibrator |
1677126 |
|
6 |
Benetech |
GM816 |
Wind Speed Anemometer |
13372555 |
3.3
Monitoring Parameters
and Frequency
Table
3.2 presents the noise monitoring parameters and
frequencies.
Table 3.2 Monitoring
Parameters and Frequencies of Noise Monitoring
|
Parameter |
Frequency
and Period |
|
LAeq (30min) L10 and L90 will be recorded for reference |
At
each station at 0700-1900 hours on normal weekdays at a frequency of once a
week |
3.4
Monitoring Methodology
The monitoring
procedures are as follows:
n The monitoring station is
set at a point 1m from the exterior of the sensitive receivers building façade
and set at a position 1.2m above the ground.
n The battery condition is
checked to ensure good functioning of the meter.
n Parameters such as
frequency weighting, the time weighting and the measurement time are set as
follows:
n frequency weighting : A
n time weighting : Fast
n measurement time : Weekly
30 minutes between 0700-1900 on normal weekdays
n Prior to and after
noise measurement, the meter shall be calibrated using the calibrator for 94.0
dB at 1000 Hz. If the difference in the calibration level before and after measurement
is more than 1.0 dB, the measurement will be considered invalid and repeat of
noise measurement is required after re-calibration or repair of the equipment.
n Noise monitoring should
be cancelled in the presence of fog, rain, and wind with a steady speed
exceeding 5 m/s, or wind with gusts exceeding 10 m/s.
n Noise measurement
should be paused during periods of high intrusive noise if possible and
observation shall be recorded when intrusive noise is not avoided.
n At the end of the
monitoring period, the Leq, L10 and L90 are recorded.
In addition, site conditions and noise sources are recorded on a standard
record sheet.
3.5
Maintenance /
Calibration
Maintenance
and Calibration procedures are as follows:
n The microphone head of
the sound level meter and calibrator should be cleaned with a soft cloth at
quarterly intervals.
n The sound level meter and calibrator should be calibrated annually by a
HOKLAS laboratory.
n Relevant calibration certificates are provided in Appendix D.
3.6.1
According
to the EM&A Manual, three noise monitoring locations, namely KTD1, KTD2 and
KER1, are covered by this Contract within the South Apron Area of Former Kai Tak Airport. The other two noise quality monitoring
locations, which are identified in Cha Kwo Ling area,
are farther than 300m away from the site boundary and thus not covered by this
Contract. The monitoring works in Cha Kwo Ling area
are covered by other Contract(s) respectively.
3.6.2
According
to the approved alternative baseline air quality and noise monitoring locations
(EPD reference: EP2/K19/A/21 Pt.5), the original monitoring locations (KTD1,
KTD2 and KER1) are proposed to be replaced by alternative monitoring locations
(KTD1a, KTD2a and KER1b) for noise monitoring, they are summarized in Table 3.3
and shown in Figure
2.
Table 3.3 Location
of Noise Monitoring Station
|
Monitoring
Station |
Location |
|
KTD1a |
Centre of Excellence in Paediatrics
(Children’s Hospital) |
|
KTD2a |
G/IC Zone next to Kwun Tong
Bypass (Future Hospital at Site 3C1) |
|
KER1b |
Site Boundary at Cheung Yip Street |
3.7.1 The schedule of noise monitoring in reporting month is provided in Appendix E.
3.7.2 During the monitoring month, at KTD1a, non-project related construction
activities at the nearby construction site and road traffic along Shing Cheong Road were observed in the surroundings. At
KTD2a, road traffic along the Kwun Tong By-pass was
observed. At KER1b, road traffic along Cheung Yip Street was observed. Major
noise sources including noise emission from plant & PME and some other
construction activities, travel of vehicles, loading and unloading of C&D
waste were observed in the site. The above factors may affect the monitoring
results.
3.7.3 No raining and wind with speed over 5 m/s was observed during noise
monitoring according to the onsite observation. The weather conditions during
the monitoring month are provided in Appendix
K.
3.7.4 The noise monitoring data are summarized in Table 3.4. Detailed monitoring data are
presented in Appendix G.
Table 3.4 Summary of Noise Impact Monitoring
Results
|
Time Period |
Leq
(30min) dB(A) (Range) |
Action
Level |
Limit
Level |
||
|
Noise Monitoring
Stations |
|||||
|
KTD1a |
KTD2a |
KER1b |
|||
|
0700-1900 hrs
on normal weekdays |
62 - 71 |
61 - 72 |
64 - 73 |
When one documented
complaint is received |
75 dB(A) |
Note:
KTD1a: Façade Measurement
KTD2a & KER1b: Free-field
measurement (+3dB(A) correction has been applied)
3.7.5 No Action / Limit Level exceedance of location KTD1a, KTD2a and KER1b was
recorded for construction noise in the reporting month.
3.7.6 The Action and Limit Levels for noise impact monitoring have been set are
presented in Appendix C.
3.7.7 The Event and Action Plan for noise is given in Appendix H.
3.8
Comparison of Noise Monitoring Results with EIA Predictions
3.8.1 The noise monitoring data was compared with the EIA predictions as
summarized in Table 3.5.
Table
3.5 Comparison
of Noise Monitoring data with EIA predictions
|
Monitoring
Station |
Receiver
Reference |
Maximum
Predicted Mitigated Construction Noise Level, dB(A) |
Maximum
Leq (30min) dB(A) In March 2018 |
|
KTD1a |
KTD1 |
74 |
71 |
|
KTD2a |
KTD2 |
75 |
72 |
|
KER1b |
KER1 |
75 |
73 |
Note:
Maximum Predicted Mitigated Construction Noise Level extracted from Table
5.13 of EIA Report, EIAR-174/2013.