3.1
Noise monitoring was conducted
in accordance with the EM&A Manuals.
Appendix A shows the established Action/Limit Levels for the
environmental monitoring works.
3.2
Noise monitoring was conducted
at four designated monitoring stations, namely N5, N6, N7 and N8, as summarized
in Table 3.1. Figures
Table
3.1 Noise
Monitoring Stations
|
Monitoring Stations |
Description |
|
N5 |
At the podium level of Garden Villa |
|
N6 |
On the roofing of |
|
N7 |
On the roofing of |
|
N8 |
At the ground level of 187 Tin Sam Tsuen |
3.3
Table 3.2 summarizes the noise
monitoring equipment model being used. Copies of calibration certificates are attached in Appendix B.
Table
3.2 Noise
Monitoring Equipment
|
Equipment |
Model and Make |
Qty. |
|
Integrating Sound Level Meter |
B&K Model 2238 |
5 |
|
Calibrator |
B&K 4231 |
3 |
|
Wind
Speed Anemometer |
Vane Anemometer, Model 451104 |
1 |
Monitoring Parameters, Frequency and Duration
3.4
Table 3.3 summarizes the
monitoring parameters, frequency and total duration of monitoring. The noise
monitoring schedule is shown in Appendix C.
Table
3.3 Noise
Monitoring Parameters, Frequency and Duration
|
Monitoring
Stations |
Parameters |
Period |
Frequency |
Measurement |
|
N5 |
L10(30
min.)dB(A) L90(30
min.)dB(A) Leq(30
min.)dB(A) |
0700-1900
hrs. on weekdays |
Once
per week |
Facade |
|
N6 |
Facade |
|||
|
N7 |
Facade |
|||
|
N8 |
Facade |
Monitoring Methodology and QA/QC Procedures
·
The Sound Level Meter was set
on a tripod at a height of
·
The battery condition was
checked to ensure the correct functioning of the meter.
·
Parameters such as frequency
weighting, the time weighting and the measurement time were set as follows:
—
frequency weighting : A
—
time weighting : Fast
—
time measurement : Leq (30 min) for
daytime noise monitoring /
3 consecutive Leq (5 min) for
restricted hour noise monitoring
·
Prior to and after each noise
measurement, the meter was calibrated using a Calibrator for 94.0 dB at 1000
Hz. If the difference in the
calibration level before and after measurement was more than 1.0 dB, the measurement
would be considered invalid and repeat of noise measurement would be required
after re-calibration or repair of the equipment.
·
The wind speed was frequently
checked with the portable wind meter.
·
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 record sheet.
·
Noise measurement was paused
during periods of high intrusive noise if possible and observation was recorded
when intrusive noise was not avoided.
·
Noise monitoring was cancelled
in the presence of fog, rain, and wind with a steady speed exceeding
3.5
The microphone head of the
sound level meter and calibrator was cleaned with soft cloth regularly.
3.6
The meters were sent to the
supplier to check and calibrate on yearly intervals.
3.7
Noise monitoring was performed
as scheduled in the reporting month.
Results and graphical presentations are shown in Appendix G.
3.8
No Action/Limit Level exceedance
was recorded during the reporting month.
3.9
The major noise source at
Stations N5 and N6 during night time was identified as road traffic noise from