3.1
Monitoring Requirement
3.1.1
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
3.2.1
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).
3.2.2
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.
3.2.3
Measurements shall be recorded to the nearest
0.1dB. Sound level meters 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
3.4.1
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
3.5.1
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 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: () in 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 KER1a) for noise monitoring.
3.6.3
According
to the approved relocation of monitoring location KER1a (EPD reference: () in
EP2/K19/A/21 pt.5), the monitoring location KER1a are proposed to be relocated
by alternative monitoring locations KER1b for noise monitoring.
3.6.4
According
to the approved relocation of monitoring location KTD2a (EPD reference: () in
EP2/K19/A/21 pt.6), the monitoring location KTD2a are proposed to be relocated
by alternative monitoring locations KTD2b for noise monitoring.
3.6.5
The
most updated locations 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, project
related construction activities and road traffic along Shing Cheong Road were observed
in the surroundings. At KTD2b, road traffic along the Kwun Tong By-pass and
non-project related construction activities at the nearby construction site 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 of location
KTD1a, KTD2b 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 and 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.