4.1
In accordance with Updated
EM&A Manual, construction noise monitoring was conducted in terms of the
A-weighted equivalent continuous sound pressure level (Leq)
to monitor the construction noise arising from the construction activities. The
regular monitoring frequency for each monitoring station shall be on a weekly
basis and conduct one set of measurements between 0700 and 1900 hours on normal
weekdays. Appendix B shows the
established Action and Limit Levels for the environmental monitoring works.
4.2
Impact noise monitoring
was conducted at the monitoring stations, as shown in Figure 3 and 4
according to Table 1.1 of Updated EM&A Manual. Table
4.1 describes the locations of the noise monitoring stations.
Table 4.1 Location
of Noise Monitoring Stations
|
Contract No. |
Monitoring Station(s) |
Location(s) |
|
ND/2019/06 |
CP-FLN-NMS1[2] |
Belair
Monte |
|
ND/2019/05 |
CP-FLN-NMS2[3] |
Scattered
Village Houses in Tong Hang |
|
ND/2019/01 |
CP-KTN-NMS2[4] |
Residential
Buildings at Ma Tso Lung |
|
CP-KTN-NMS3[5] |
Fung Kong
Garden |
|
|
ND/2019/01 |
CP-KTN-NMS5 |
N/A |
|
ND/2019/02 |
CP-KTN-NMS6 |
Ho Sheung Heung, Hau Ku Shek Ancestral Hall, Hung Shing
Temple & Pai Fung Temple and Sin Wai Nunnery |
Remarks:
[1]: Noting
that construction phase noise monitoring at the other proposed monitoring
stations (e.g. planned), where access is permitted, will be conducted during
the relevant works contract(s).
[2]: Since
the distance between monitoring station and site boundary of ND/2019/03 under
EP-473/2013/A exceeds 300m. The monitoring station is not applicable to
ND/2019/03.
[3]: Since
the distance between monitoring station and site boundary of ND/2019/03 under
EP-473/2013/A exceeds 300m. The monitoring station is not applicable to
ND/2019/03.
[4],[5]: Since the distance between monitoring station and site
boundary of ND/2019/03 under EP-468/2013/A exceeds 300m. The monitoring station
is not applicable to ND/2019/03.
4.3
Integrating Sound Level
Meter was used for impact noise monitoring. The meters are Type 1 sound level
meter capable of giving a continuous readout of the noise level readings
including equivalent continuous sound pressure level (Leq)
and percentile sound pressure level (Lx) that also complied with International Electrotechnical Commission Publications 651:1979 (Type 1)
and 804:1985 (Type 1) specifications. Table
4.2 summarizes the noise monitoring equipment being used. Copies of
calibration certificates are attached in Appendix
C.
Table 4.2 Noise
Monitoring Equipment
|
Equipment |
Manufacturer |
Model |
Quantity |
|
Sound & Vibration Analyser |
BSWA |
BSWA 801 |
1 |
|
Sound Level Meter |
BSWA |
BSWA 308 |
2 |
|
Acoustical Calibrator |
Brüel & Kjær |
4231 |
1 |
|
SVANTEK |
SV30A |
2 |
4.4
Table 4.3 summarises
the monitoring parameters, frequency and total duration of monitoring. The noise monitoring schedule is shown
in Appendix D.
Table
4.3 Noise Monitoring Parameters, Duration
and Frequency
|
Contract No. |
Monitoring Stations |
Parameter |
Duration |
Frequency |
Measurement |
|
ND/2019/06 |
CP-FLN-NMS1 |
L10(30 min.) dB(A) L90(30 min.) dB(A) Leq(30 min.)dB(A) (as six
consecutive Leq, 5min readings) |
0700-1900 hrs on normal
weekdays |
Once per week |
Façade |
|
ND/2019/05 |
CP-FLN-NMS2[3] |
||||
|
ND/2019/01 |
CP-KTN NMS2[4] |
Free-field[1] |
|||
|
CP-KTN NMS3[5] |
|||||
|
ND/2019/01 |
CP-KTN NMS5 |
||||
|
ND/2019/02 |
CP-KTN-NMS6 |
Façade |
Remarks:
[1]:
Correction of +3dB (A) for Free-field Measurement.
[2]: A-weighted equivalent continuous sound pressure level (Leq). It is the constant noise level which,
under a given situation and time period, contains the same acoustic energy as
the actual time-varying noise level.
L10 is the level exceeded for 10% of the
time. For 10% of the time, the sound or noise has a sound pressure level above
L10.
L90 is the level exceeded for 90% of the
time. For 90% of the time, the noise level is above this level.
[3]:
Since the distance between monitoring station and site boundary of ND/2019/03
under EP-473/2013/A exceeds 300m. The monitoring station is not applicable to
ND/2019/03.
[4],[5]: Since the distance between monitoring station and site
boundary of ND/2019/03 under EP-468/2013/A exceeds 300m. The monitoring station
is not applicable to ND/2019/03.
·
The microphone head of
the sound level meter was positioned at 1m from the exterior of the noise
sensitive I and lowered sufficiently so that the building’s external wall acted
as a reflecting surface;
·
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.) dB(A)
(as six consecutive Leq, 5min readings) during non-restricted hours (i.e. 0700-1900 hrs on normal weekdays)
·
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;
·
During the monitoring
period, the Leq, L90 and L10 were recorded. In
addition, site conditions and noise sources were recorded on a standard record sheet;
·
Noise measurement was paused temporarily during periods of high intrusive
noise (e.g. dog barking, helicopter noise) if possible and observation record
during measurement period should be provided; and
·
Noise monitoring was 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. The wind
speed should be checked with a portable wind speed meter capable of measuring
the wind speed in m/s.
4.5
The microphone head of
the sound level meter and calibrator were cleaned with a soft cloth at
quarterly intervals.
4.6
The sound level meter and
calibrator were checked and calibrated at yearly intervals.
4.7
Immediately prior to and
following each noise measurement, the accuracy of the sound level meter should
be checked using an acoustic calibrator generating a known sound pressure level
at a known frequency. Measurements would be accepted as valid only if the
calibration levels before and after the noise measurement agreed to within 1.0 dB.
4.8
The noise monitoring
results are summarized in Table 4.4.
Detailed monitoring results and graphical presentations of noise monitoring are
shown in Appendix F. The weather
information for the reporting month is summarized in Appendix I.
Table 4.4 Summary
Table of Noise Monitoring Results during the Reporting Month
|
Contract No. |
Monitoring Station |
Noise
Level Leq (30 min), dB(A) |
Baseline Level, dB(A) |
Limit Level, dB(A) |
|
ND/2019/06 |
CP-FLN-NMS1 |
56.7-69.1 |
69.9 |
75 |
|
ND/2019/05 |
CP-FLN-NMS2[1] |
57.9-68.2 |
59.6 |
|
|
ND/2019/01 |
CP-KTN NMS2[2] |
53.3-59.7 |
58.6 |
|
|
CP-KTN NMS3[3] |
46.6-58.2 |
51.6 |
||
|
ND/2019/01 |
CP-KTN NMS5 |
51.3-60.0 |
57.2 |
|
|
ND/2019/02 |
CP-KTN-NMS6 |
58.7 |
55.1 |
Remarks:
[1]: Since
the distance between monitoring station and site boundary of ND/2019/03 under
EP-473/2013/A exceeds 300m. The monitoring station is not applicable to
ND/2019/03.
[2],[3]: Since the distance between monitoring station and site
boundary of ND/2019/03 under EP-468/2013/A exceeds 300m. The monitoring station
is not applicable to ND/2019/03.
4.9
All noise monitoring was
conducted as scheduled in the reporting month. No complaint was received during
the reporting. No Action/Limit Level exceedance was recorded. The
summary of exceedance record in reporting month is shown in Appendix K.
4.10 According to our field observations, the major noise source
identified at the designated noise monitoring stations in the reporting month
are as follows:
Table 4.5 Observation
at Noise Monitoring Stations
|
Contract No. |
Monitoring Station |
Location |
Major Noise Source |
|
ND/2019/06 |
CP-FLN-NMS1 |
Belair Monte (Existing) |
Road Traffic at Ma Sik
Road |
|
ND/2019/05 |
CP-FLN-NMS2[1] |
Scattered Village House in Tong Hang (Existing) |
Road Traffic near Tong
Hang |
|
ND/2019/01 |
CP-KTN-NMS2[2] |
Residential Buildings at Ma Tso Lung (Existing) |
Road Traffic near Ma Tso Lung |
|
ND/2019/01 |
CP-KTN-NMS3[3] |
Fung Kong Garden (Existing) |
Road Traffic near Fung
Kong Garden |
|
ND/2019/01 |
CP-KTN-NMS5 |
N/A |
Other construction site |
|
ND/2019/02 |
CP-KTN-NMS6 |
Ho Sheung
Heung, Hau Ku Shek
Ancestral Hall, Hung Shing Temple & Pai Fung Temple and Sin Wai Nunnery (Existing) |
Road Traffic near Ho Sheung Heung |
Remarks:
[1]: Since
the distance between monitoring station and site boundary of ND/2019/03 under
EP-473/2013/A exceeds 300m. The monitoring station is not applicable to
ND/2019/03.
[2],[3]: Since the distance between monitoring station and site
boundary of ND/2019/03 under EP-468/2013/A exceeds 300m. The monitoring station
is not applicable to ND/2019/03.
4.11 Should any project related non-compliance of the criteria
occur, action in accordance with the Action Plan in Appendix J shall be carried out.