Agreement No. CE 35/2006(CE)
Kai Tak Development Engineering Study
cum Design and Construction of Advance Works
– Investigation, Design and Construction
Kai Tak Development
environmental
monitoring and audit manual
Contents
6............ Noise
Impact. 6-1
6.1 Introduction. 6-1
6.2 Noise Parameters. 6-1
6.3 Monitoring Equipment 6-1
6.4 Monitoring Locations. 6-1
6.5 Baseline Monitoring. 6-1
6.6 Impact Monitoring.
6-2
6.7 Event and Action Plan. 6-2
6.8 Mitigation Measures. 6-2
List of Tables
Table 6.1
Noise Monitoring Stations
Table 6.2
Action and Limit Levels for Construction Noise
Table 6.3
Event/Action Plan for Construction Noise
6
Noise Impact
6.1
Introduction
6.1.1
In
this section, the requirements, methodology, equipment, monitoring locations,
criteria and protocols for the monitoring and audit of noise impacts during the
construction phase of the Project are presented. The proposed mitigation
measures during construction and operation phase of the Project are also
described in this section.
6.1.2
Construction noise
impacts from this Project are predicted at the identified Noise Sensitive
Receivers (NSRs). Noise mitigation measures would be required to reduce
noise levels to the stipulated standard. A noise monitoring programme
shall be undertaken to ensure such mitigation measures would be implemented
properly.
6.2
Noise Parameters
Construction
Phase
6.2.1
The construction noise
level shall be measured in terms of the A-weighted equivalent continuous sound
pressure level (Leq). Leq (30 minutes) shall be
used as the monitoring parameter for the time period between 0700 and 1900 hours
on normal weekdays. For all other time periods, Leq (5 minutes) shall be
employed for comparison with the Noise Control Ordinance (NCO) criteria.
6.2.2
Supplementary
information for data auditing, statistical results such as L10 and L90
shall also be obtained for reference. A sample data record sheet based on
the one presented in the EM&A Guidelines for Development Projects in Hong Kong is shown in Appendix B.
The ET Leader may modify the data record sheet for this EM&A programme, of
which the format should be agreed by the ER and the IEC.
6.3
Monitoring Equipment
6.3.1
As referred to in the
Technical Memorandum (TM) issued under the NCO, sound level meters in
compliance with the International Electrotechnical Commission Publications 651:
1979 (Type 1) and 804: 1985 (Type 1) specifications shall be used for carrying
out the noise monitoring. Immediately prior to and following each noise
measurement the accuracy of the sound level meter shall be checked using an
acoustic calibrator generating a known sound pressure level at a known
frequency. Measurements may be accepted as valid only if the calibration
level from before and after the noise measurement agree to within 1.0 dB.
6.3.2
Noise measurements
shall not be made in fog, rain, wind with a steady speed exceeding 5m/s or wind
with gusts exceeding 10 m/s. The wind speed shall be checked with a
portable wind speed meter capable of measuring the wind speed in m/s.
6.3.3
The ET is responsible
for the provision of the monitoring equipment. He shall ensure that
sufficient noise measuring equipment and associated instrumentation are
available for carrying out the baseline monitoring, regular impact monitoring
and ad hoc monitoring. All the equipment and associated instrumentation
shall be clearly labelled.
6.4
Monitoring Locations
6.4.1
The locations of
construction noise monitoring stations are summarized in Table 6.1 and
shown in Figure 2.2.
These locations represent the worst affected sensitive receivers during
construction phase of the Project.
Table
6.1
Noise Monitoring Stations
Noise Monitoring Station
|
NSR ID in EIA Report
|
Noise Monitoring Location
|
M1
|
N4
|
Buddhist Chi King Primary
School
|
M2
|
N5
|
S.K.H Kowloon
Bay Kei
Lok Primary
School
|
M3
|
N10
|
Rhythm Garden
|
M4
|
N11
|
Cognitio College
|
M5
|
N13
|
Lee Kau
Yan Memorial
School
|
M6
|
N14
|
Nam Yuen
|
M7
|
N23
|
Holly Carpenter
Primary School
|
M8
|
N27
|
CCC Kei To Secondary School
|
M9
|
N28
|
Po Leung
Kuk Ngan
Po Ling
College
|
M10
|
PN34
|
Site 1B1 (Planned)
|
M11
|
PN38
|
Site 1B4 (Planned)
|
6.4.2
The status and
locations of noise sensitive receivers may change after issuing this
Manual. If such case exists, the ET Leader shall propose updated
monitoring locations and seek approval from EPD and agreement from the ER and
the IEC before baseline monitoring commences.
6.4.3
When alternative
monitoring locations are proposed, the monitoring locations shall be chosen
based on the following criteria:
(i) Monitoring at
sensitive receivers close to the major site activities which are likely to have
noise impacts;
(ii) Monitoring at the noise
sensitive receivers as defined in the Technical Memorandum; and
(iii)
Assurance of minimal
disturbance to the occupants during monitoring.
6.4.4
The monitoring station
shall normally be at a point 1 m from the exterior of the sensitive receiver
building facade and be at a position 1.2 m above the ground. If there is
problem with access to the normal monitoring position, an alternative position
may be chosen, and a correction to the measurements shall be made. For
reference, a correction of +3 dB(A) shall be made to the free field
measurements. The ET shall agree with the IEC on the monitoring position
and the corrections adopted. Once the positions for the monitoring
stations are chosen, the baseline monitoring and the impact monitoring shall be
carried out at the same positions.
6.5
Baseline Monitoring
Construction Phase
6.5.1
The ET shall carry out
baseline noise monitoring prior to the commencement of the construction
works. The baseline monitoring shall be carried out daily for a period of
at least two weeks. Before commencing the baseline monitoring, the ET shall
develop and submit to the IEC the baseline monitoring programme such that the
IEC can conduct on-site audit to ensure accuracy of the baseline monitoring
results.
6.5.2
There shall not be any
construction activities in the vicinity of the stations during the baseline
monitoring.
6.5.3
In exceptional cases,
when insufficient baseline monitoring data or questionable results are
obtained, the ET Leader shall liaise with the ER, EPD and IEC to agree on an
appropriate set of data to be used as a baseline reference and submit to the ER
and IEC for agreement and EPD for approval.
6.6
Impact Monitoring
Construction Phase
6.6.1
Noise monitoring shall
be carried out at all the designated monitoring stations. The monitoring
frequency shall depend on the scale of the construction activities. The
following is an initial guide on the regular monitoring frequency for each
station on a weekly basis when noise generating activities are underway:
·
one set of measurements
between 0700 and 1900 hours on normal weekdays.
6.6.2
If construction works
are extended to include works during the hours of 1900 – 0700 as well as public
holidays and Sundays, additional weekly impact monitoring shall be carried out
during respective restricted hours periods. Applicable permits under NCO
shall be obtained by the Contractor.
6.6.3
If a school exists near
the construction activity, noise monitoring shall be carried out at the
monitoring stations for the schools during the school examination
periods. The ET Leader shall liaise with the school’s personnel and the
Examination Authority to ascertain the exact dates and times of all examination
periods during the course of the contract.
6.6.4
In case of
non-compliance with the construction noise criteria, more frequent monitoring,
as specified in the Action Plan in Table 6.3, shall be carried
out. This additional monitoring shall be continued until the recorded
noise levels are rectified or demonstrated to be unrelated to the construction
activities.
6.7
Event and Action Plan
Construction Phase
6.7.1
The Action and Limit
levels for construction noise are defined in Table 6.2. Should
non-compliance of the criteria occur, action in accordance with the Event and
Action Plan in Table 6.3 shall be implemented.
Table
6.2
Action and Limit Levels for Construction Noise
Time Period
|
Action Level
|
Limit Level
|
0700 – 1900 hours on normal weekdays
|
When one documented compliant is
received
|
75 dB(A) *
|
Notes: If works are to be
carried out during restricted hours, the conditions stipulated in the
Construction Noise Permit (CNP) issued by the Noise Control Authority have to
be followed.
* 70 dB(A) and 65 dB(A) for
schools during normal teaching periods and school examination periods,
respectively.
6.8
Mitigation Measures
Construction Phase
6.8.1
To alleviate the
construction noise impact on the affected NSRs, movable noise barriers and
acoustic mats are proposed to be provided for particular items of plant and
construction works. It is anticipated that a movable noise barrier with a
cantilevered upper portion located within 5m from any static or mobile plant
can provide 5 dB(A) noise reduction for mobile plant and 10 dB(A) noise
reduction for static plant. The barrier material shall have a surface mass of
not less than 14 kg/m2 on skid footing with 25 mm thick internal
sound absorptive lining to achieve the maximum screening effect.
6.8.2
In addition, the good
site practices listed below shall be adopted by all the Contractors to further
ameliorate the noise impacts.
·
Only well-maintained
plant should be operated on-site and plant should be serviced regularly during
the construction program.
·
Silencers or mufflers
on construction equipment should be utilised and should be properly maintained
during the construction program.
·
Mobile plant, if any, should be sited as
far away from NSRs as possible.
·
Machines and plant
(such as trucks) that may be in intermittent use should be shut down between
works periods or should be throttled down to a minimum.
·
Plant known to emit
noise strongly in one direction should, wherever possible, be orientated so
that the noise is directed away from the nearby NSRs.
·
Material stockpiles and
other structures should be effectively utilised, wherever practicable, in
screening noise from on-site construction activities.
6.8.3
If the above measures
are not sufficient to restore the construction noise quality to acceptable
levels upon the advice of ET Leader, the contractor shall liaise with the ET
Leader to identify further mitigation measures. They shall be proposed to
ER for approval, and the contractor shall then implement these additional
mitigation measures.
Operation Phase
6.8.4
The following direct
mitigation measures, as shown in Figure
2.3, have been proposed in the EIA.
·
Low noise surfacing on
Road L2; and
·
Low noise surfacing on
Road L4.
6.8.5
The EIA report has
provided the maximum allowable sound power levels for fixed noise
sources. The SWL criteria shall be implemented and refined by the
Contractor. The Contractor should also carry out a noise commissioning
test for all fixed noise sources before operation of the Project, in order to
ensure compliance of the operational airborne noise levels with the TM’s
stipulated noise standard.
6.8.6
The implementation schedule
for the recommended mitigation measures is presented in Appendix A4.
Table
6.3
Event/Action Plan for Construction Noise
EVENT
|
ACTION
|
ET
|
IEC
|
ER
|
CONTRACTOR
|
Action Level being exceeded
|
1. Notify ER, IEC and
Contractor;
2. Carry out investigation;
3. Report the results of
investigation to the IEC, ER and Contractor;
4. Discuss with the IEC and
Contractor on remedial measures required;
5. Increase monitoring frequency
to check mitigation effectiveness.
(The above actions should be taken within 2 working days after the
exceedance is identified)
|
1. Review the
investigation results submitted by the ET;
2. Review the
proposed remedial measures by the Contractor and advise the ER accordingly;
3. Advise the ER on
the effectiveness of the proposed remedial measures.
(The above actions should be taken within 2
working days after the exceedance is identified)
|
1. Confirm receipt of
notification of failure in writing;
2. Notify Contractor;
3. In consolidation with the
IEC, agree with the Contractor on the remedial measures to be implemented;
4. Supervise the implementation
of remedial measures.
(The above actions should be taken within 2 working
days after the exceedance is identified)
|
1. Submit noise
mitigation proposals to IEC and ER;
2. Implement
noise mitigation proposals.
(The above actions should be taken within 2 working
days after the exceedance is identified)
|
Limit Level being exceeded
|
1. Inform IEC, ER, Contractor
and EPD;
2. Repeat measurements to
confirm findings;
3. Increase monitoring
frequency;
4. Identify source and
investigate the cause of exceedance;
5. Carry out analysis of
Contractor’s working procedures;
6. Discuss with the IEC,
Contractor and ER on remedial measures required;
7. Assess effectiveness of
Contractor’s remedial actions and keep IEC, EPD and ER informed of the
results;
8. If exceedance stops, cease
additional monitoring.
(The above actions should be taken within 2 working days after the
exceedance is identified)
|
1. Discuss amongst ER, ET, and
Contractor on the potential remedial actions;
2. Review Contractor’s remedial
actions whenever necessary to assure their effectiveness and advise the ER
accordingly.
(The above actions should be taken within 2 working days after the
exceedance is identified)
|
1. Confirm receipt of
notification of failure in writing;
2. Notify Contractor;
3. In consolidation with the
IEC, agree with the Contractor on the remedial measures to be implemented;
4. Supervise the implementation
of remedial measures;
5. If exceedance continues,
consider stopping the Contractor to continue working on that portion of work
which causes the exceedance until the exceedance is abated.
(The above actions should be taken within 2 working days after the
exceedance is identified)
|
1. Take immediate action to
avoid further exceedance;
2. Submit proposals for remedial
actions to IEC and ER within 3 working days of notification;
3. Implement the agreed
proposals;
4. Submit further proposal if
problem still not under control;
5. Stop the relevant portion of
works as instructed by the ER until the exceedance is abated.
(The above actions should be taken within 2 working days after the
exceedance is identified)
|