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.
3.3
Monitoring
Parameters and Frequency
Table 3.2 presents the noise
monitoring parameters and frequencies.
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.
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.
3.7.5 No Action / Limit Level exceedance 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.