4
NOISE
General
4.2.1
Noise impacts have been
assessed in accordance with the criteria and methodology given in the Technical
Memoranda (TMs) under the Noise Control Ordinance (NCO), and the Technical
Memorandum on Environmental Impact Assessment Process (EIAO-TM).
4.2.2
The NCO and EIAO provide
the statutory framework for noise control.
Assessment procedures and standards relevant to this study are set out
in four TMs listed below:
l
EIAO-TM
l
TM on Noise from
Construction Work other than Percussive Piling (GW-TM)
l
TM on Noise from
Percussive Piling (PP-TM)
l
TM on Noise from
Construction Work in Designated Areas (DA-TM)
Construction Noise – General Construction
4.2.3
The NCO provides the
statutory framework for noise control of construction work, other than
percussive piling, using powered mechanical equipment (PME) between the hours
of 1900 and 0700 hours or at any time on Sundays and general holiday (that is,
restricted hours). Noise control on
construction activities taking place at other times is subject to the Criteria
for Evaluating Noise Impact stated in Table 1B of Annex 5 in the EIAO-TM. The noise limit is Leq (30 minutes)
75 dB(A) at the façades of dwellings and 70 dB(A) at the façade of
schools (65 dB(A) during examinations).
The standards apply to uses which rely on opened windows for
ventilation.
4.2.4
Between 1900 and 0700
hours and all day on Sundays and public holidays, activities involving the use
of powered mechanical equipment (PME) for the purpose of carrying out
construction work is prohibited unless a Construction Noise Permit (CNP) has
been obtained. A CNP may be granted
in cases where the noise can be contained within the Acceptable Noise Level
(ANL) at the NSRs. ANLs are
assigned depending upon the Area Sensitivity Ratings (ASRs). The corresponding basic noise levels
(BNLs) for evening and nighttime periods are given in Table 4.1.
Table 4.1 Construction Noise
Criteria for Activity other than Percussive Piling
|
Time Period
|
Basic Noise
Level (BNLs)
|
|
ASR A
|
ASR B
|
ASR C
|
|
Evening (1900 to 2300 hours) (1)
|
60
|
65
|
70
|
|
Night (2300 to 0700 hours)
|
45
|
50
|
55
|
Notes: (1) Includes Sundays
and Public Holidays during daytime and evening
4.2.5
Despite any description
or assessment made in this EIA Report on construction noise aspects, there is
no guarantee that a Construction Noise Permit (CNP) will be issued for the
project construction. The Noise Control Authority will consider a
well-justified CNP application, once filed, for construction works within
restricted hours as guided by the relevant Technical Memoranda issued under the
Noise Control Ordinance. The Noise Control Authority will take into account
contemporary conditions/ situations of adjoining land uses and any previous
complaints against construction activities at the site before deciding whether
to grant a CNP. Nothing in this EIA
Report should bind the Noise Control Authority in making its decision. If a CNP is to be issued, the Noise
Control Authority should include in the permit any condition it thinks
fit. Failure to comply with any
such conditions will lead to cancellation of the CNP and prosecution under the
NCO.
4.2.6
Percussive piling is
prohibited between 1900 and 0700 hours on any weekday not being a general
holiday and at any time on Sunday or general holiday. A CNP is required for carrying out of
percussive piling between 0700 and 1900 hours on any day not being a general
holiday. PP-TM sets out the
requirements for working and determination of the permitted hours of
operations. ANLs for percussive
piling for different type of NSRs are shown in Table 4.2.
Table 4.2 Acceptable Noise Levels
for Percussive Piling
|
NSR Window Type or Means of Ventilation
|
ANL, dB(A)
|
|
(i) NSR (or part of NSR) with no windows or other opening
|
100
|
|
(ii) NSR with central air conditioning system
|
90
|
|
(iii) NSR with windows or other openings but without
central air conditioning system
|
85
|
Note: 10 dB(A) should be subtracted from the
ANLs shown above for NSRs which are hospitals, medical clinics, educational
institutes, courts of law or other NSRs which are considered by the Authority
to be particularly sensitive to noise.
4.2.7
Effective from 1 October
1999, diesel, pneumatic and / or steam hammers are not allowed to be used in Hong Kong.
The permitted hours of operation for carrying out of percussive piling
work, subject to the issuance of a CNP, are listed in Table 4.3.
Table 4.3 Permitted Hours of
Operation for Percussive Piling
|
Amount
by which Corrected Noise Level (CNL) exceeds Acceptable Noise Level (ANL),
CNL-ANL
|
Permitted
hours of operation on any day not being a general holiday
|
|
10
dB(A) < CNL-ANL
|
0800
to 0900 AND 1230 to 1330 AND 1700 to 1800
|
|
0
dB(A) < CNL-ANL £ 10 dB(A)
|
0800
to 0930 AND 1200 to 1400 AND 1630 to 1800
|
|
CNL-ANL
£ 0 dB(A)
|
0700
to 1900
|
4.2.8
Under the TM on Noise
from Construction Work in Designated Areas, the use of five types of Specified
Powered Mechanical Equipment (SPME) and three types of Prescribed Construction
Work (PCW) within a designated area during restricted hours would require a
valid CNP. The SPME includes
hand-held breaker, bulldozer, concrete lorry mixer, dump truck and hand-held
vibratory poker. The PCW are:
·
Erecting or dismantling of formwork or
scaffolding.
·
Loading, unloading or handling of rubble, wooden
boards, steel bars, wood or scaffolding material.
·
Hammering.
4.2.9
In general, it should
not be presumed that a CNP would be granted for carrying out PCW within a
designated area during restricted hours.
The CNP may be granted for the execution of construction works during
restricted hours involving the use of PME and/ or SPME if the relevant
Acceptable Noise Levels and criteria stipulated in the GW-TM and DA-TM can be
met.
Operational Noise - Traffic Noise
4.2.10
Annex 5 “Criteria for
Evaluating Noise Impact” of the EIAO-TM defines the criteria L10 (1 hour)
for road traffic noise at various NSRs which rely on openable window for
ventilation:
·
70 dB(A) at the façades of dwellings, hotels,
offices.
·
65 dB(A) at the façades of schools, places of
public worship, courts of law, place where unaided voice communication is
required.
·
55 dB(A) at the façades of hospital.
4.2.11
For traffic noise
assessment, the roads within 300 m of the Project boundary have been included
in the assessment. The roads are
classified into one of the following categories:
·
‘Existing’ Roads - that is, roads that are unchanged
or subject to minor changes by the Project.
·
‘New’ Roads - roads that are completely new or major
modification to an existing road section that will result in 25% increase in
lanes or substantial changes in alignment or characters of the existing road
due to the proposed Project.
4.2.12
The ‘New’ roads defined for the assessment are
shown in Appendix 4.1.
4.2.13
The noise contribution
from “New” roads should be less than 70 dB(A) at any dwelling (less than 65
dB(A) for educational institutions), so as to satisfy the relevant noise criteria, and there should not be any
increase in traffic noise impact. In
the case of an NSR where existing noise levels already exceed the relevant
criteria, any increase in noise level contributed
by the “New” roads should not be greater than 1 dB(A).
4.2.14
If any façades of NSRs are still exposed to
predicted noise levels exceeding the relevant noise criteria after the
implementation of all direct mitigation measures, provision of indirect
technical remedies in the form of acoustic insulation and air conditioning
should be considered under the EIAO-TM and the ExCo Directive “Equitable
Redress for Persons Exposed to Increased Noise Resulting from the Use of New
Roads”. The eligibility for
indirect technical remedies will be tested against the following three
criteria:
·
The predicted overall noise level from the “New”
road, together with other traffic noise in the vicinity must be above a
specified noise level (for example, 70 dB(A) for domestic premises and 65 dB(A)
for educational institutions, all in L10 (1 hour));
·
The predicted overall noise level is at least
1.0 dB(A) more than the prevailing traffic noise level, that is, the total
traffic noise level existing before the works to construct the road were
commenced; and
·
The contribution
to the increase in the predicted overall noise level from the “New” road must
be at least 1.0 dB(A).
4.3.1
The existing land uses
in the vicinity of the Project site are commercial, GIC, educational,
residential and recreational uses. The dominant existing noise source comes
from the road traffic on busy TMR and Castle
Peak Road.
No major industrial noise source is found within the Project
boundary.
4.4.1
Existing and planned NSRs including domestic
premises and educational institutions within 300m from the project boundary were identified in
accordance with Section 3 of Annex 13 of the EIAO-TM. For the purpose of the noise assessment,
a number of representative NSRs which were considered to be potentially
worst-affected NSRs were selected for the assessment and has been agreed with
EPD (The relevant correspondence letter is attached in Appendix 4.2). Photographs of all the identified
existing NSRs are provided in Appendix 4.3. Tuen Mun Hospital, one of identified existing
NSR, is provided with central air conditioners and do not rely on openable
window for ventilation, therefore, it has been excluded in the assessment. The representative NSRs for construction
and traffic noise assessments are summarised in Tables
4.4
below and their locations are illustrated in Figure
4.1.
Table 4.4 Summary of
Representative Noise Assessment Point
|
NSR
|
Description
|
Use
|
No. of
Storey
|
|
TMHQ
|
Block F, Tuen
Mun Hospital
Quarter
|
Residential
|
20
|
|
TLLF
|
The Church of Christ in China Tam
Lee Lai
Fun Memorial
Secondary School
|
Educational Institution
|
6
|
|
LB1
|
Lakeshore Building
|
Residential
|
20
|
|
MYS
|
SKH Mung Yan Primary School
|
Educational Institution
|
7
|
|
BG1
|
Block A, Brilliant
Garden
|
Residential
|
11
|
|
VB
|
Victory Building
|
Residential
|
25
|
|
KF
|
Kam Fat Building
|
Residential
|
18
|
Construction Noise
4.5.1
The Project is scheduled to commence in early
2008 and to be completed in late 2009.
All construction tasks would be carried out during unrestricted hours
(0700 to 1900 hours Monday to Saturday excluding general holidays). Details of construction tasks are as
follows:
·
Tree felling (in the vicinity of widen road
section);
·
At grade road widening, i.e. excavation and
slope works, realign the kerb;
·
Road paving and road marking;
·
Construction of noise barrier; and
·
Installation of high mast lighting.
4.5.2
In view of limited work
site, the above construction activities would not take place concurrently.
4.5.3
The programme of the
Project would have about three months overlapping with the project of “Traffic
Improvement to Tuen Mun Road Town Centre Section” which would be commenced in
the third quarter of September 2008 and be completed in the second quarter of
2010. However, separate distance
between these two sites would be more than 300m, therefore, cumulative noise impacts are
therefore not expected. There is no
any other concurrent project undertaken within 300m of the study area during construction period of
the Project. Noise sources from the
areas greater than 300m of a
given NSR are excluded from the assessment
4.5.4
In accordance with the
EIAO-TM, the methodology outlined in the GW-TM has been used for the assessment
of construction noise (excluding percussive piling). Sound Power Levels (SWLs) of the
equipment were taken from Table 3 of this TM. Schedules of powered mechanical
equipment (PME) for different construction tasks of the Project and other
concurrent construction activities of other projects during normal daytime
working hours are presented in Appendix 4.4. As the worst case scenario, on-time
percentage for all PME of each construction activity is assumed to be
100%. The Project Proponent has
confirmed that the plant inventory is valid for the Project works.
4.5.5
It is assumed that all
PME items required for a particular construction activity would be located at
the notional or probable source position of the segment where such activity is
to be performed. The assessment is
based on the cumulative SWL of PME likely to be used for each location, taking
into account the construction period in the vicinity of the receiver
location. To predict the noise
level, PME is divided into groups required for each discrete construction
task. The objective is to identify
the worst case scenario representing those items of PME that would be in use
concurrently at any given time. The
sound pressure level of each construction task is calculated, depending on the
number of plant and distance from receivers. The noise levels at NSRs are then
predicted by adding up the SWLs of all concurrent construction tasks.
4.5.6
A positive 3 dB(A)
façade correction is added to the predicted noise levels in order to account
for the facade effect at each NSR.
Operation Noise
4.5.7
Traffic noise was
predicted using the methodology provided in the UK Department of Transport
Calculation of Road Traffic Noise (CRTN) 1988. The assessment was based on projected
peak hour flows for the worst year within 15 years after opening of the road.
The roads proposed under the Project are scheduled to open in 2009. Therefore,
the traffic data for year 2024, which has been endorsed by Transport Department
(see Appendix 4.5), was adopted for the assessment. The projected 2024 peak hour traffic
flows are presented in Appendix 4.5.
4.5.8
Traffic speeds for the
roads adopted in the noise model are summarised as follows:
Road Speed
Limit
Tuen
Mun Road 70 km per
hour
Castle
Peak Road 50 km per
hour
Other
Roads 50
km per hour
4.5.9
The traffic speed for
all existing roads has been made reference to the Traffic Aids provided by
Transport Department.
4.5.10
The road network,
proposed building layout and all other features that could have noise screening
or reflective effects were digitised in the road traffic noise model. The roads
were divided into segments, each of which was assigned a road layout
number. A road layout defined the
road width, opposing traffic lane separation, road surface type and traffic
mix, flow and road design speed.
There is only one lane of six lanes at existing road section of TMR
within the study area is provided with low noise surfacing material, as a
conservative approach, impervious road surface was assumed for TMR main
alignment as well as other roads within the study area in the assessment. Noise levels were calculated at each
receiver point at various elevations.
4.5.11
It is noted that NSR
TLLF is located at about 3.9m
from the road kerb of TMR. In
accordance with CRTN, if the assessment is less than 4m from the carriageway edge, there may be an
uncertainty in the distance attenuation correction. Therefore, the predicted noise levels at
NSR TLLF was based on site noise measurement data and then normalized with 2024
peak traffic flow.
Construction Phase
4.6.1
Potential construction
noise impacts may arise from road works, slope works, and construction of noise
mitigation measures.
Operation Phase
4.6.2
Road traffic noise
impact would be caused by vehicular traffic from widened TMR section and the
existing roads.
Construction Phase
4.7.1
Except NSR MYS, the NSRs
as mentioned in Table 4.4 in
the vicinity of the Project site are selected for construction noise impact
assessment. The exclusion of NSR
MYS in the assessment is due to a large separate distance between the NSR and
work site (about 113 m).
If the predicted construction noise levels at other representative NSRs which
are located closest to the work site (less than 113 m from the work site) would comply with the noise
criterion, the predicted noise levels at NSR MYS should also comply with the
criterion. During normal daytime working hours, exceedance of the construction
noise criteria were predicted at residential NSR LB1 and educational NSR TLLF
in the absence of mitigation measures.
The predicted noise levels at representative NSRs are in the range of 63 to 85 dB(A).
Mitigation measures are considered necessary. A summary of the unmitigated
construction noise levels of the representative NSRs during normal daytime
working hours within the construction period of the Project is listed in Table
4.5. Details of construction
noise calculations and results are presented in Appendix 4.4.
Table 4.5 Summary of Unmitigated
Construction Noise Levels at Representative NSRs During Normal Daytime
Working Hours
|
Representative NSRs
|
Use
|
Criteria
dB(A)
|
Predicted Unmitigated
Construction Noise Levels during Normal
Daytime Working Hour (dB(A))
|
|
TMHQ
|
Residential
|
75
|
63 - 71
|
|
TLLF
|
Educational Institution
|
70/65#
|
73 – 85
|
|
LB1
|
Residential
|
75
|
74 – 82
|
|
BG1
|
Residential
|
75
|
64 – 69
|
|
VB
|
Residential
|
75
|
66 – 74
|
|
KF
|
Residential
|
75
|
73 – 74
|
Note: # For
normal daytime working hours, the noise criteria are 70 dB(A) and 65 dB(A) for
normal teaching periods and examination periods, respectively.
Operation Phase
4.7.2
Traffic noise levels
have been predicted at a total of 8 representative noise assessment points
including existing residential dwellings and educational institutions. Appendix
4.6 gives the breakdown of the noise contributions
from the “New” roads and existing roads at the representative NSRs.
4.7.3
Without the noise
mitigation measures in place, the predicted noise levels at the identified NSRs
are in the range of 65 dB(A) to 85 dB(A). Results indicated that NSR TMHQ, VB,
MYS and LB1 would exceed the traffic noise criteria due to both ‘New’ roads and
existing roads; while exceedance predicted at other NSRs would be due to
existing roads only. Noise
mitigation measures on ‘New’ roads are required to alleviate the adverse
traffic noise impact.
Construction Noise
4.8.1
In order to reduce the
excessive noise impacts at the affected NSRs during normal daytime working
hours, mitigation measures such as adopting quiet powered mechanical equipment,
is recommended. The above mitigation
measures have been vetted and confirmed by the Engineer as being practicable in
completing the works within scheduled timeframe. The Contractor may be able to
obtain particular models of plant that are quieter than the PMEs given in
GW-TM. It is considered too restrictive to specify that a Contractor has to use
specific items of plant for the construction operations. It is practical to
specify the total SWL of all plant to be used on site so that the Contractor is
allowed some flexibility to select plant to suit his needs.
4.8.2
In this assessment, the recommended
quiet PME are taken from the BS 5228: Part 1: 1997 and the PME are known to be
available in Hong Kong.
4.8.3
The lists of quiet PME
adopted in the construction tasks of the Project during normal daytime working
hours are presented in Appendix 4.4.
4.8.4
With the use of quiet
PMEs, the predicted noise levels at all residential NSR would comply with
construction noise criteria.
However, noise exceedance was predicted at educational NSR TTLF for
following construction activities.
Road Paving – exceedance by 8 dB(A) in the normal
teaching period and 13 dB(A) in the examination period;
Road Marking – exceedance by 4 dB(A) in the normal
teaching period and 9 dB(A) in the examination period;
Construction of Noise Barriers – exceedance by 4 dB(A)
in the examination period;
4.8.5
In order to further
alleviate construction noise impact, it is proposed to adopt movable noise
barrier (3m high) for the PMEs
during road paving and road marking in the vicinity of NSR TLLF. It is anticipated that a movable noise
barrier located within 5m from
mobile plant can provide at least 5 dB(A) noise reduction. The barrier material shall have a
surface mass of not less than 14 kg/m2
on skid footing with 25mm
thick internal sound absorptive lining to achieve the maximum screening
effect. Use of barrier has been
confirmed by the Engineer as being practical from engineering and programming
point of view.
4.8.6
In view of the limited
buffer distance between NSR TLLF and the nearest work area (road paving) is
around 12m, the predicted noise
level would still exceed the noise criteria by 3 dB(A) in normal teaching
period and 8 dB(A) in examination period during road paving. Practical mitigation measures (i.e. use
of quiet PMEs and movable noise barriers) have been exhausted, taking into
account the engineering and programming point of view. In order to further alleviate the
construction noise impacts, only one PME (asphalt paver or vibratory roller) is
allowed to be operated. The
predicted noise level at NSR TLLF would comply with the criterion of 70 dB(A)
in normal teaching period. In the
examination period, it is recommended to cease paving activity if the paving
work area is less than 30m
from the NSR TLLF or only one PME (asphalt paver or vibratory roller) is
allowed to be operated if the work area is not less than 22m from NSR TLLF.
4.8.7
With the implementation
of movable noise barrier for PMEs during road marking, the predicted noise
levels at NSR TLLF would comply with the criteria of 70 dB(A) in the normal
teaching period. In order to comply
with the criterion of 65 dB(A) in the examination period, the road marking
activity should be carried out at least 18m
from the NSR TLLF.
4.8.8
Movable noise barrier is
also proposed for excavator and compressor during construction of noise barrier
in the vicinity of NSR TLLF in the examination period. As noise screening effect from movable
noise barrier is not effective for piling, it is proposed to avoid the piling
operation for construction of noise barriers or implemented by other quiet
construction method during examination period. Movable noise barrier would be provided
for excavator and compressor. The
predicted noise levels at NSR TLFF would comply with the criteria of 65
dB(A).
4.8.9
A summary for mitigated noise levels
during normal daytime working hours at representative NSRs is presented in Table
4.6.
Table 4.6 Summary of Mitigated
Construction Noise Levels at Representative NSRs During Normal Daytime Working Hours
|
Representative NSRs
|
Use
|
Criteria
dB(A)
|
Predicted Mitigated
Construction Noise Levels during Normal
Daytime Working Hour (dB(A))
|
|
TMHQ
|
Residential
|
75
|
52 – 64 (1)
|
|
TLLF
|
Educational Institution
|
70/65#
|
64 – 70 (2) (3) (4)
|
|
LB1
|
Residential
|
75
|
63 – 75 (1)
|
|
BG1
|
Residential
|
75
|
53 – 62 (1)
|
|
VB
|
Residential
|
75
|
54 – 67 (1)
|
|
KF
|
Residential
|
75
|
63 – 67 (1)
|
Note: # For
normal daytime working hours, the noise criteria are 70 dB(A) and 65 dB(A) for
normal teaching periods and examination periods, respectively.
(1)
Adoption
of quiet PMEs
(2)
Road
marking - Adoption of quiet PMEs and movable noise barrier during normal
teaching period and examination period.
The work area should be located not less than 18m from NSR TLLF during examination period.
(3)
Construction
of noise barrier - Adoption of quiet PMEs and movable noise barrier during
examination period, piling operation for construction of noise barrier would
also be ceased during examination period
(4)
Road
paving - Adoption of quiet PMEs, movable noise barrier and scheduling of PMEs
during normal teaching period, only one PME to be operated and the work area
not less than 22m
from NSR TLLF or cease operation of PMEs if work area less than 30m from NSR TLLF during examination
period.
Operation Noise
4.8.10
Direct mitigation measures
would be proposed for ‘New’ roads (i.e. within the meaning of Item A.1 of
Schedule 2 of EIAO-TM) if there would be adverse environmental impact. If the
NSRs are affected by noise from other existing roads, direct mitigation
measures are required to reduce the noise from the ‘New’ roads to a level that
it
(i)
is not higher than the noise standard; and
(ii)
has no significant contribution
to the overall noise from other existing roads, if the cumulative noise level (i.e.
noise from the “New” road together with other existing roads) exceeds the noise
standard.
4.8.11
The proposed noise
mitigation measures as shown in Figure 4.2 are summarised as follows:
·
A section of a 100m long 6m
high cantilevered barrier with 3.5m cantilever inclined at 23° on the Kowloon
bound of TMR
·
A section of 80m long 6m high cantilevered barrier with 2.5m cantilever inclined at 23° on the Yuen Long bound of TMR
·
Low noise material
surfacing on the ‘New’ road section (185m for Kowloon bound and 195m for Yuen Long bound)
4.8.12
Appendix 4.6 presents the breakdown of noise contribution
from the “New” roads and existing roads at all representative NSRs with the
proposed cantilevered noise barriers and low noise material road surfacing in
place.
4.8.13
With the proposed direct
mitigation measures in place, the predicted overall noise levels at most of the
NSRs would still exceed the relevant noise limits due to the noise
contributions from existing roads. However, the ‘New’ road noise contributions
to the overall noise levels would be less than 1.0 dB(A) and the ‘New’ road
noise levels at these NSRs would all be below the relevant noise limits. Hence, no further direct mitigation
measures are considered effective in mitigating the noise impact.
4.9
Evaluation of Residual Environmental Impacts
Construction Noise
4.9.1
With the implementation
of the above-mentioned mitigation measures, the construction noise levels at
all representative residential and educational NSRs are predicted to comply
with the noise standards stipulated in the EIAO-TM.
4.9.2
In
order to further ameliorate the construction noise impacts, the good site
practices listed below should be adopted by all the Contractors. Although the noise mitigating effects
are not easily quantifiable and the benefits may vary with the site conditions
and operating conditions, good site practices are easy to implement and do not
impact upon the works schedule.
l
Only well-maintained
plant should be operated on-site and plant should be serviced regularly during
the construction program.
l
Silencers or mufflers on
construction equipment should be utilized and should be properly maintained
during the construction program.
l
Mobile plant, if any,
should be sited as far away from NSRs as possible.
l
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.
l
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.
l
Material stockpiles and
other structures should be effectively utilised, wherever practicable, in
screening noise from on-site construction activities.
l
Noisy work to be
conducted in non-school hours or long holiday such as summer vacation as
possible.
Operation Noise
4.9.3
With
the proposed direct noise mitigation measures in place, the ‘New’ road noise
contributions to the overall noise levels at all representative NSRs would be
less than 1.0 dB(A) and the ‘New’ road noise levels would all be below the
relevant noise criteria. No adverse
noise impacts arising from the ‘New’ roads are predicted at any of the
representative NSRs. Noise exceedances at the representative NSRs, if any,
would be due to the existing roads.
4.9.4
The
contribution to the increase in predicted overall noise level from the ‘New’
roads is below 1.0 dB(A), therefore none of the representative NSRs is eligible
for consideration for indirect technical remedies in the form of acoustic
insulation and air conditioning under the EIAO-TM and the ExCo Directive
“Equitable Redress for Persons Exposed to Increased Noise Resulting from the
Use of New Roads”.
Construction Noise
4.10.1
An EM&A programme is
recommended to be established according to the predicted occurrence of noisy
activities. All the recommended mitigation measures for daytime normal working
activities should be incorporated into the EM&A programme for
implementation during construction.
Details of the programme are provided in the stand-alone EM&A
Manual.
Operation Noise
4.10.1
Road traffic noise
levels should be monitored at representative NSRs, which are in the vicinity of
the recommended direct noise mitigation measures, during the first year after
road opening. Details of the programme are provided in the stand-alone EM&A
Manual.
Construction Noise
4.11.1
This
assessment has predicted the construction noise impacts of the Project during
normal daytime working hours. With the use of quiet PME, movable barriers and
scheduling of PMEs/construction activities, the noise levels at all
representative NSRs would comply with the construction noise standard.
Operation Noise
4.11.2
The
potential road traffic noise impacts have been assessed based on the worst case
traffic flows in 2024. The noise levels at some NSRs are predicted to exceed
the EIAO-TM traffic noise criteria due to both ‘New’ road and existing roads.
As a result, direct mitigation measures have been proposed to mitigate the
noise impacts at NSRs TMHQ, VB, MYS and LB1 where ‘New’ road noise
contributions to the overall noise levels would be more than 1.0 dB(A).
4.11.3
With
two sections of 6m high
cantilevered noise barrier and low noise material surfacing on ‘New’ road in
place, the ‘New’ road noise contributions
to the overall noise levels at all representative NSRs would be less than 1.0
dB(A) and the ‘New’ road noise levels would all be below the relevant noise
criteria, though the overall noise levels at most of the NSRs would still
exceed the relevant noise criteria. However, it should be noted that such noise
exceedances at the representative NSRs are due to the existing roads.
4.11.4
Monitoring
of road traffic noise is recommended to verify the effectiveness of the
mitigation scheme during the first year after road opening.