MTR
Corporation Limited
MTR Lai Chi Kok Station Pedestrian Subway and Entrance Works
Baseline
Noise Monitoring Report
Environmental Pioneers & Solutions Limited
8/F, Chaiwan Industrial Centre Building
20 Lee Chung Street, Chaiwan, Hong Kong
Tel: 2889 0569 Fax:
2856 2010
APPROVAL SHEET
Prepared and Certified by: ET Leader (Environmental Pioneers & Solutions Limited)
Signature: _____________________ Date: __________________
Miss Patricia Chung
(ET Leader)
* ET –
Environmental Team
TABLE OF CONTENTS
1.1 Project
Background Information
2.1 Monitoring
Methodology and Parameters
2.4 Monitoring
Results and Observations
3. REVISIONS FOR
INCLUSION IN THE EM&A MANUAL
APPENDIX 1 –
Monitoring Locations
APPENDIX 2 –
Calibration Certificates for Sound Level Meters
APPENDIX 3 –
Monitoring Results for Monitoring Station at Liberte (R1)
APPENDIX 4 –
Monitoring Results for Monitoring Station at the Pacifica (R2)
EXECUTIVE SUMMARY
In accordance with the Environmental Permit (EP-0253/2006) and the Environmental Monitoring and Audit Manual (EM&A Manual) for the Project “MTRC Lai Chi Kok Station Pedestrian Subway and Entrance Works”, baseline monitoring of noise is required. This report presents the baseline monitoring results performed in April to May 2007.
As stipulated in the EM&A Manual, baseline noise monitoring was conducted at two monitoring stations (R1 and R2). Data obtained from the monitoring was processed to obtain the background noise levels in both the normal and restricted time periods.
The baseline noise levels for the two stations were measured daily for a period of two weeks. Data collected was reviewed and analyzed. Details of the monitoring locations and results are present in this report
1. INTRODUCTION
1.1 Project Background Information
A pedestrian subway connecting the Liberté and the Pacifica and the existing Lai Chi Kok MTR Corporation Limited (MTRCL) station in Kowloon is proposed.
The purpose of this Project is to improve the accessibility to the Lai Chi Kok Station (LCK) from the existing and future developments by providing MTRC passengers a more direct, convenient and comfortable access to the LCK. Extending to the south of the West Kowloon Corridor, the subway will reduce at-grade pedestrian movements and provide significant improvements to the environmental and comfort levels experienced by passengers accessing LCK and people crossing Lai Chi Kok Road.
In accordance with Section 5(10) of the
Environmental Impact Assessment Ordinance (EIAO)(Cap499), the project would
constitute a material change to an exempted designed project as LCK has been in
operation before the Ordinance came into operation and effect. The Project
Profile (PP-269/2005) and the associated Environmental Monitoring & Audit
Manual (EM&A Manual) were prepared by the Consultant Ove Arup &
Partners HK Ltd. during the period Oct 2005 to April 2006. An Environmental
Permit (EP) EP-253/2006 was issued in August 2006 by the Environmental
Protection Department (EPD) to MTRCL regarding the construction project. In
accordance with the EP and the Environmental Monitoring & Audit Manual
(EM&A Manual), baseline monitoring of noise is required to be carried out
prior to the commencement of construction of the project.
1.2 Purpose
By establishing the baseline level of noise, the performance of the construction contractor shall be measured in meeting required environmental protection standards and requirements under the Environmental Permit (EP-253/2006), during the course of the construction work. This report presents the baseline monitoring requirements, methodologies and result of noise measures in accordance with the EM&A Manual.
2. NOISE MONITORING
2.1 Monitoring Methodology and Parameters
Monitoring was undertaken to establish noise baseline levels in the vicinity of the works areas Lai Chi Kok (LCK) MTR Station, and to provide data against which any environmental impacts due to construction activities can be compared.
Table 2.1 summarizes the monitoring parameters, frequency and duration of baseline noise monitoring. Consecutive noise measurements were carried out over the daytime period (0700-1900) for every normal weekday and Saturday for two consecutive weeks using the LAeq(30min) parameters (27 April 2007 – 13 May 2007). Monitoring parameter of LAeq(5min) was used for each of the restricted period (i.e.1900-2300, 2300-0700 and Sundays/General Holidays).
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Table 2.1 - Noise Monitoring Parameters, Period and Frequency |
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Time Period |
Duration |
Parameters |
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Daytime: 0700-1900 |
30 min |
LAeq, L10,
L90 |
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Restricted Periods: 1900-2300; 2300-0700; and Sundays/General Holidays |
5 min |
|
2.2 Monitoring Stations
In accordance with the EM&A Manual, monitoring stations were established at 2 locations, which are summarized in Table 2.2 and depicted in Appendix 1:
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Table 2.2 –
Noise Monitoring Stations |
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Sensitive
Receiver No. |
Location |
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R1 |
Podium, Block
7, Liberte |
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R2 |
Podium, Tower
1, The Pacifica |
2.3 Monitoring Equipment
Baseline monitoring was conducted using SVAN sound analysis equipment – SVAN 949, which complied with the International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1 985 (Type 1) Specifications as referred to in the Technical Memorandum to the Noise Control Ordinance. The equipment were calibrated and verified by certified laboratory or manufacturer every two years to ensure they perform to the same level of accuracy as stated in the manufacturer’s specification. Before and after each measurement, the reading of sound level meter was checked with the acoustic calibrator and the measurements were accepted as valid if the calibration levels before and after the noise measurement agreed to within 1.0 dB. Calibration Certificates of the sound level meter and acoustic calibrator are given in Appendix 2.
Free field and weatherproof microphone was extended 1m from the exterior of the sensitive receivers building façade and with an unobstructed field of view of the proposed construction site. Measurements were recorded to the nearest 0.1 dB.
2.4 Monitoring Results and Observations
30 minute, “fast” detector response, LAEQ, L10, and L90 levels were recorded. Monitoring during the restricted periods (i.e. 1900-2300, 2300-0700 of next day and Sundays/General Holiday) comprise of LAeq(5mins) readings in each of the restricted period. The monitoring results are summarized in Table 2.3 to 2.6. All monitoring data and associated graphical presentation are given in Appendix 3 and 4.
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Table 2.3 Summary of Day-Time (0700-1900) Monitoring Results |
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Daytime 0700-1900 hrs on normal weekdays |
Range of Noise
Level, dB(A) LAeq(30
min) |
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Mean |
Max |
Min |
|
|
R1 |
74.0 |
74.3 |
72.9 |
|
R2 |
74.3 |
74.5 |
73.3 |
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Table 2.4 Summary of Evening-Time (1900-2300) Monitoring Results |
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1900-2300 hrs on normal weekdays |
Range of Noise
Level, dB(A) LAeq(5
min) |
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|
Mean |
Max |
Min |
|
|
R1 |
72.4 |
73.5 |
70.8 |
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R2 |
72.3 |
74.5 |
71.0 |
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Table 2.5 Summary of Night-Time (2300-0700) Monitoring Results |
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2300-0700 hrs of the next day |
Range of Noise
Level, dB(A) LAeq(5
min) |
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|
Mean |
Max |
Min |
|
|
R1 |
68.7 |
72.0 |
64.9 |
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R2 |
68.9 |
72.7 |
65.6 |
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Table 2.6 Summary of Sunday / General Holidays Monitoring Results |
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Sundays / General Holidays |
Range of Noise
Level, dB(A) LAeq(5
min) |
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|
Mean |
Max |
Min |
|
|
R1 |
71.1 |
73.0 |
68.4 |
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R2 |
71.2 |
72.7 |
68.6 |
The weather conditions during the monitoring period were mostly fine. No noise monitoring was conducted under increment weather condition such as in the presence of fog, rain, wind with a steady speed exceeding 5 m/s or gust exceeding 10 m/s.
Since the monitoring stations were established at podium level of Liberte (R1) and the Pacifica (R2) facing the proposed construction site on Lai Chi Kok Road, noise from vehicular traffic with a considerable portion of buses, cars, and trucks were considered the dominant noise source. For a busy road, it was noted that the noise level was fairly constant throughout the day.
3. REVISIONS FOR INCLUSION IN THE EM&A MANUAL
The baseline monitoring was conducted according to the Environmental Monitoring & Audit Manual (EM&A Manual) for noise.
The monitoring methodology, parameters monitored and monitoring locations are in line with the EM&A Manual. All two stations, at Liberte (R1) and the Pacifica (R2), are designated in the EM&A Manual.
4. CONCLUSION
Baseline monitoring was conducted at the two suggested monitoring stations, namely Liberte (R1) and the Pacifica (R2) from 27 April 2007 to 13 May 2007. Baseline levels have been established for weekday periods (0700-1900) as well as three restricted periods (1900-2300; 2300-0700; Sundays/ General holidays).
Noise level of mid-seventy dB(A) had been consistently recorded throughout the weekdays for both stations. Noise level of early-seventy dB(A) had been recorded in the evening restricted period (1900-2300) for both stations, while the night period level were at around 68-69 dB(A); these baseline levels are high compared to requirements under the Noise Control Ordinance.
The major noise sources are noticed from the vehicular traffic of Lai Chi Kok Road. The baseline monitoring results are considered representative to the ambient noise level.
4.1 Action and Limit Levels
From the baseline results and in accordance with the EM&A Manual, the Action and Limit levels are set as follows:
Action level exceedance occurs when one or more documented complaints are received.
Limit level is set at LAEQ(30 min) 75 for normal working hours, as suggested in EIAO-Technical Memorandum. For restricted periods, limit level shall be subjected to control under the Noise Control Ordinance (NCO) and the condition in the Construction Noise Permit (CNP).
The Action and Limit levels for the sensitive receivers at R1 and R2 are summarized in Table 3.1, which would be applied for compliance assessment of construction noise for this project.
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Table 3.1 Action and Limit Levels for Construction Noise at Sensitive
Receivers R1 and R2 |
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Time Period |
Action |
Limit |
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Daytime 0700 – 1900 hrs
on normal weekdays |
When
one documented complaint is received |
75 dB(A) |
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0700 – 2300hrs
on holidays; and 1900 – 2300 hrs on all other days |
Subject to the control of Noise Control
Ordinance |
|
|
2300 – 0700 hrs
of next day |
Subject to the control of Noise Control
Ordinance |
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APPENDIX 1 – Monitoring Locations
APPENDIX 2 – Calibration Certificates for Sound Level Meters
