4 NOISE.. 4-1
4.1 Introduction. 4-1
4.2 Environmental
Legislation, Policies, Plans, Standards and Criteria. 4-2
4.3 Description
of the Environment 4-3
4.4 Sensitive
Receivers. 4-3
4.5 Assessment
Methodology. 4-3
4.6 Identification
of Environmental Impacts. 4-3
4.7 Prediction
and Evaluation of Environmental Impacts. 4-3
4.8 Mitigation
of Adverse Environmental Impacts. 4-3
4.9 Evaluation
of Residual Impacts. 4-3
4.10 Construction
Activities during Restricted Hours. 4-3
4.11 Environmental
Monitoring and Audit 4-3
4.12 Conclusion. 4-3
List of Tables
Table 4.1 Construction
Noise Criteria for Activity other than Percussive Piling. 4-2
Table 4.2 Acceptable
Noise Levels for Percussive Piling. 4-2
Table 4.3 Permitted
Hours of Operation for Percussive Piling. 4-3
Table 4.4 Acceptable
Noise Level for Fixed Plant Noise. 4-3
Table 4.5 Representative
Existing and Planned Noise Sensitive Receivers. 4-3
Table 4.6 Summary of
Construction Tasks and Stages. 4-3
Table 4.7 Number of
Ventilation Fans required for the Proposed Ventilation Buildings under Congestion
Condition 4-3
Table 4.8 Summary of
Unmitigated Construction Noise Levels at Representative NSRs During Normal
Daytime Working Hours. 4-3
Table 4.9 Summary of
Mitigated Construction Noise Levels at Representative NSRs during Normal
Daytime Working Hours. 4-3
Table 4.10 Construction
Noise Residual Impacts. 4-3
Table 4.11 Summary of
Unmitigated Construction Noise Levels at Representative NSRs During Restricted
Hours 4-3
Table 4.12 Summary of
Mitigated Construction Noise Levels at Representative NSRs During Restricted
Hours 4-3
4
NOISE
4.1.1
This section presents the
potential noise impacts arising from the proposed Project during construction
and operational phases. It is
expected that construction noise impact will arise from the proposed Project as
well as the nearby concurrent projects (i.e. Central Reclamation Phase III
(CRIII) and Hong Kong Convention and
Exhibition Centre Atrium Link Extension (HKCEC ALE). Cumulative daytime
construction noise impacts are assessed in this study. At the time of carrying out this EIA,
information on the two potential future railway projects (i.e. Shatin to
Central Link (SCL) and North
Hong Kong Island Line (NIL)) were not
available, therefore the cumulative noise impact arising from these two railway
projects has not been assessed in this section. An indicative assessment for
construction works undertaken within restricted hours has also been undertaken.
4.1.2
During the operational phase,
traffic noise impacts are anticipated and traffic noise assessment has
therefore been undertaken at the representative noise sensitive receivers
within 300m from the
boundary of the development area (the Study Area). Assessments for helicopter noise from
the proposed permanent helipad, ventilation noise from the proposed East and Central Ventilation Buildings
and operation noise from re-provisioned Wan Chai North Public Transport
Interchange have been undertaken to evaluate the impacts on the nearby
sensitive receivers. A
re-provisioned saltwater pumping station near the existing Wanchai East Sewage
Screening Plant will also incorporate fixed noise sources but it is located
underground and buffered from potential receivers. No significant fixed noise
impact from the pumping station is anticipated, a quantitative assessment has
not been carried out in this EIA.
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 Annexes 5 and 13
in 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 are set out in five 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)
l
TM on Noise from Places other
than Domestic Premises, Public Places or Construction Sites (IND-TM)
Construction Noise – General Construction
Works
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).
4.2.4
Between 1900 and 0700 hours and
all day on Sundays and public holidays, activities involving the use of 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 provided that the
Acceptable Noise Level (ANL) for the NSRs can be complied with. ANLs are assigned depending upon the
area sensitive rating (ASR). The
corresponding basic noise levels (BNLs) for evening and night time periods are
given in Table 4.1.
Table 4.1 Construction
Noise Criteria for Activity other than Percussive Piling
|
|
Basic Noise Level (BNLs), Leq (30-min)
dB(A)
|
|
|
ASR B
|
ASR C
|
|
Evening (1900
to 2300 hours) (1)
|
60
|
65
|
70
|
|
|
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 making
his decision in granting a CNP.
Nothing in this EIA Report shall bind the Noise Control Authority in
making his decision. If a CNP is to
be issued, the Noise Control Authority shall include in it any condition he
thinks fit. Failure to comply with
any such conditions will lead to cancellation of the CNP and prosecution action
under the NCO.
4.2.6
For the purpose of assessing
the feasibility of carrying out construction works during restricted hours, the
noise sensitive receivers in the Study Area are assumed to be ‘ASR B’ in a
conservative approach. The
construction noise criteria for the sensitive receivers would be 65 dB(A) in
the evening and 50 dB(A) at night.
The Noise Control Authority would decide the Area Sensitivity Rating at
the time of assessment of such an application based on the contemporary
situations / conditions. It should
be noted that the situations / conditions around the sites may change from time
to time. The Area Sensitivity
Ratings assumed in this EIA Report are for indicative assessment only. The assessment for construction
activities during restricted hours is presented in Section 4.10.
4.2.7
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 the 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
types of NSRs are shown in Table 4.2.
Table 4.2 Acceptable Noise
Levels for Percussive Piling
|
|
|
|
|
100
|
|
NSR with
central air conditioning system
|
90
|
|
NSR with
windows or other openings but without central air conditioning system
|
85
|
Note:
10
dB(A) shall 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.
4.2.8
In accordance with PP-TM, the
permitted hours of operation for carrying out of percussive piling work
involving use of diesel, pneumatic and/or steam hammers, 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
|
|
|
|
|
|
|
4.2.9
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:
l
erecting or dismantling of
formwork or scaffolding
l
loading, unloading or handling
of rubble, wooden boards, steel bars, wood or scaffolding material
l
hammering
4.2.10
In general, it should not be
presumed that a CNP would be granted for carrying out PCW within a designated
area during the 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.
4.2.11
There are no statutory
procedures and criteria under the NCO and EIAO for assessing blasting noise
impacts. Blasting in this Project, if required, would be carried out underground.
Any such blasting
noise, which is transient and short in duration, is not assessed in this EIA.
However, the administrative and procedural control of all blasting operations
in Hong Kong is vested in the Mines Division
of the Civil Engineering and Development Department (CEDD). The Dangerous Goods
(General) Regulations, Chapter 295 also stipulates that no person shall carry
out blasting unless he possesses a valid mine blasting certificate to be issued
by the Mines Division of CEDD. The Superintendent of Mines will review the
application on a case-by-case basis before issuing the Mine Blasting
Certificate.
Operational Traffic Noise
l
70 db(A) at the façades of
dwellings, hotels, offices
l
65 db(A) at the façades of
schools, places of public worship, courts of law, places where unaided voice
communication is required
l
55 db(A) at the façades of
hospital
4.2.13 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:
l
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)); and
l
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 commence; and
l
the contribution to the
increase in the predicted overall noise level from the new road must be at
least 1.0 dB(A).
4.2.14 For the purpose of the traffic noise assessment in this Report, the
roads within 300m
from the proposed project alignment are included in the assessment. All roads are described as one of the
following:
l
‘Existing’ Roads are the roads
that are unchanged or subject to minor changes by the Project.
l
‘New’ Roads are the roads that
are completely new or existing road sections that undergo major modifications
that would cause significant traffic noise impact (i.e. road sections within
the meaning of Item A.1 of Schedule 2 of EIAO).
4.2.15 The noise contribution from “new” roads should be less than 70 dB(A)
at any dwellings (less than 65 dB(A) for educational institutions and places of
public worship), 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 be less than 1.0 dB(A).
4.2.16 In accordance with the Study Brief, the scope of the proposed road
alignment(s) has been analyzed to identify appropriate road sections within the
meaning of Item A.1 of Schedule 2 of the EIAO and other road sections for the
purpose of traffic noise impact assessment. The extent of ‘New’ roads under
this Project has been depicted in Figures
4.1 to 4.6. The
following sub-sections have identified the extent of ‘existing’ roads for the
purpose of traffic noise impact assessment.
Modifications to Fenwick Pier Street
and Convention Avenue
(Figure 4.2)
4.2.17 Except the open arena of HKAPA, the NSRs in the close vicinity of
these modified road sections would be equipped with central air-conditioning
system. Besides, the traffic flow on these road sections with the Project would
be less than that without the Project in year 2031. The traffic noise impact due to
such modification works would not be considered significant, and hence these
road sections would not be regarded as the ‘New’ roads under EIAO. Projected
traffic data with and without the Project in year 2031 has been presented in Appendix 4.1.
Modifications to Convention Avenue, Expo Drive and Expo Drive East (Figure 4.3)
4.2.18 Although the traffic flow on Expo Drive and Expo Drive East with the Project would be
more than that without the Project in year 2031, the NSRs in the close vicinity
of these two road sections are equipped with central air-conditioning system,
and hence no significant noise impact would be expected. For Convention Avenue,
the traffic flow with the Project would be less than that without the Project
in year 2031, and the road alignment would be shifted northward away from the
NSRs. The modification work to Convention
Avenue would not cause significant road traffic
noise impact on the nearest affected NSR (i.e. Causeway Centre). As a result,
these three modified road sections would not be regarded as the ‘New’ roads
under EIAO.
Modifications to Hung Hing Road (Figure 4.4)
4.2.19 Traffic flow on Hung
Hing Road with the Project would be less than that
without the Project in year 2031, and it would basically follow the existing
road alignment. The traffic noise impact on the nearby NSRs due to such
modification works would not be considered significant, and hence this road
section would not be regarded as the ‘New’ road under EIAO.
Modifications to Hing Fat Street and
Victoria Park Road
Westbound (Figure 4.5)
4.2.20 Traffic flow on Hing
Fat Street with the Project would be less than
that without the Project in year 2031, and it would basically follow the
existing road alignment. The traffic noise impact on the nearby NSRs due to
such improvement works would not be considered significant.
4.2.21 At-grade
road junction improvement will be carried out for Victoria Park Road
westbound from the connection of Slip Road 8 at west to the Hing Fat Street in order to
facilitate the
traffic moving smoothly
through the area. As part of junction improvement, a signalized junction will
be introduced at Victoria Park Road westbound before entering the Slip Road 8
to reduce the risk of weaving movement for the traffic from Tsing Fung Street
Flyover and Hing Fat Street northbound.
The Hing Fat Street southbound right turn to Victoria Park Road will be banned. Nevertheless, as existing road
alignments are basically maintained, Hing Fat Street and Victoria Park Road westbound would not be
regarded as the ‘New’ roads under EIAO.
Modifications to Eastbound
of IEC near Provident Centre and the Eastbound Slip Roads before approaching
Victoria Centre (Figure 4.6)
4.2.22 Only some marginal widening and re-surfacing at the eastbound of IEC
near Provident Centre will be carried out. There would be no
demolition and reconstruction of the existing bridge deck at this section of
IEC but only road widening and connection to the existing structure. Traffic
flow on this section of IEC with the Project (i.e. 6,535 veh/hour) would only
be 0.17% more than that without the Project (i.e. 6,524 veh/hour) in year 2031,
and the source line will be shifted away from the NSRs if the Project is in
place. The change in traffic noise level due to such marginal widening and
re-surfacing work would not be significant, therefore
these road sections would not be regarded as the “New” roads under EIAO. Besides, only re-surfacing at the
eastbound slip roads before approaching Victoria Centre will be carried out,
this section of eastbound slip road would not be regarded as the “New” road.
4.2.23 Fixed noise source such as ventilation noise is controlled by the
NCO and IND-TM. The appropriate Acceptable Noise Levels (ANL) generated by
fixed plant at neighbouring NSRs are provided in the IND-TM. The representative NSRs in the vicinity
of ventilation buildings are located in urban area and are near busy roads such
as Gloucester Road
and Island Eastern Corridor with an average daily traffic flow in excess of
30,000. Most of the NSRs would be
directly or indirectly affected by traffic noise. In this connection, the Area
Sensitivity Rating (ASR) for these NSRs has been assumed as ‘C’. However, some NSRs face north with Gloucester Road at
the back of the receivers, the ASR for these NSRs has been assumed as ‘B’. The ANLs for an ASR of ‘B’ and ‘C’ under
the IND-TM are shown in Table 4.4. Since the EIAO-TM recommends that noise
standard for fixed noise source is 5 dB(A) below the appropriate ANL, the noise
criteria of 60/65 dB(A) (daytime and evening) and 50/55 dB(A) (night-time) has
been adopted for assessment.
Table
4.4 Acceptable
Noise Level for Fixed Plant Noise
|
Time Period
|
NCO criteria
Leq (30-min) dB(A)
|
EIAO-TM
Leq (30-min)
dB(A)
|
|
ASR ‘B’
|
ASR ‘C’
|
ASR ‘B’
|
ASR ‘C’
|
|
Daytime and Evening
(0700-2300 hours)
|
65
|
70
|
60
|
65
|
|
Night-time (2300-0700
hours)
|
55
|
60
|
50
|
55
|
4.2.24 In any event, the Area Sensitivity Rating assumed in this EIA Report
is for indicative assessment. It
should be noted that the fixed noise sources are controlled under section 13 of
the NCO. At the time of
investigation, the Noise Control Authority shall determine noise impact from
concerned fixed noise sources on the basis of prevailing legislation and
practices being in force, and taking account of contemporary
conditions/situations of adjoining land uses. Nothing in this EIA Report shall bind
the Noise Control Authority in the context of law enforcement against all the
fixed noise sources being assessed.
Helicopter Noise
4.2.25 According to Table 1A
of Annex 5 “Criteria for Evaluating Noise Impact” in the EIAO-TM, the noise
criteria for helicopter noise is 90 dB(A) Lmax for offices and 85
dB(A) Lmax for domestic premises, hotels, hostels, educational
institutes, hospitals and places of worship during 0700 to 1900 hours. The standards apply to uses that rely on
openable windows for ventilation.
4.2.26 The helicopter noise is controlled under the Civil Aviation
(Aircraft Noise) Ordinance, for which, Civil Aviation Department is the control
authority.
4.3.1
The existing land uses in Wan
Chai, Causeway Bay and North Point near the proposed
development are commercial, residential and recreational uses.
4.3.2
The prevailing traffic noise
levels at representative NSRs have been predicted based on the traffic forecast
in year 2008. The projected traffic data for year 2008 has been presented in Appendix 4.2. As shown in Appendix 4.3, the overall noise levels
at representative NSRs would range from 56 to 87 dB(A). The dominant existing noise source
comes from the road traffic on busy Gloucester
Road, Victoria Park
Road and Island Eastern Corridor.
4.3.3
Since the works programme of
WDII & CWB project will overlap with the CRIII and HKCEC ALE projects in
some periods, cumulative construction noise impacts would be expected at some
noise sensitive receivers.
4.4.1
In order to evaluate the
construction and operational noise impacts from the Project alignments,
representative existing and planned noise sensitive receivers (NSRs) within 300m from the boundary of the Project
(Study Area) are identified for assessment. Only the first layer of NSRs has been
identified for assessment because it would provide acoustic shielding to those
receivers at further distance behind. As the centrally air-conditioned
buildings do not rely on opened windows for ventilation, the noise standard as
stipulated in Table 1 of EIAO-TM would not be applicable, and hence these
buildings have not been identified for noise impact assessment. Table 4.5 shows the representative NSRs
for this noise impact assessment. In the absence of the programme of
planned/committed noise sensitive developments, construction noise impact
assessment would only focus on existing NSRs. The representative NSRs selected
for assessments of construction noise, road traffic noise, fixed noise and
helicopter noise have been shown in Figure 4.7. The
photographs of the representative NSRs are shown in Appendix 4.4. These representative assessment points for
quantitative noise assessment have been agreed with the Environmental
Protection Department (see Appendix 15.1).
Table
4.5 Representative
Existing and Planned Noise Sensitive Receivers
|
NSR
|
Section
|
Location
|
Use
|
Ground elevation (mPD)
|
No. of Floors
|
|
N1
|
Wanchai
|
HKAPA (Open Arena)
|
Performing Arts Centre
|
5.0
|
G/F
|
|
N2
|
Wanchai
|
Causeway Centre
|
Residential
|
4.0
|
42
|
|
N3
|
Wanchai
|
Gloucester Road 169-170
|
Residential
|
3.7
|
12
|
|
N4
|
Wanchai
|
Kam Kwok Building
|
Residential
|
3.7
|
18
|
|
N5
|
Wanchai
|
Hyde Centre
|
Residential
|
3.7
|
22
|
|
N6
|
Causeway Bay
|
Elizabeth House
|
Residential
|
3.7
|
21
|
|
N7
|
Causeway Bay
|
Riviera Mansion
|
Residential
|
4.3
|
15
|
|
N8
|
Causeway Bay
|
Marco Polo Mansion
|
Residential
|
4.3
|
15
|
|
N9
|
Tin Hau
|
Viking Garden
|
Residential
|
4.0
|
25
|
|
N10
|
Tin Hau
|
Victoria Court
|
Residential
|
4.0
|
18
|
|
N11
|
Tin Hau
|
Mayson Garden
|
Residential
|
4.0
|
24
|
|
N12
|
Tin Hau
|
Gordon House
|
Residential
|
4.0
|
15
|
|
N13
|
Tin Hau
|
Belle House
|
Residential
|
3.6
|
24
|
|
N14
|
Tin Hau
|
Hoi Tao Building
|
Residential
|
4.0
|
30
|
|
N15
|
Tin Hau
|
Staff Quarters of FEHD
|
Residential
|
4.0
|
4
|
|
N16
|
Tin Hau
|
Victoria Centre
|
Residential
|
4.0
|
30
|
|
N17
|
Tin Hau
|
Harbour Heights
|
Residential
|
4.3
|
44
|
|
N17-A
|
Tin Hau
|
Harbour Heights
|
Residential
|
4.3
|
44
|
|
N18
|
North Point
|
City Garden, Block 10
|
Residential
|
4.0
|
27
|
|
N18-A
|
North Point
|
City Garden, Block 11
|
Residential
|
4.0
|
27
|
|
N18-B
|
North Point
|
City Garden, Block 10
|
Residential
|
4.0
|
27
|
|
N19
|
North Point
|
City Garden, Block 7
|
Residential
|
4.0
|
27
|
|
N19-A
|
North Point
|
City Garden, Block 7
|
Residential
|
4.0
|
27
|
|
N20
|
North Point
|
Hong Kong Baptist Church
Henrietta Secondary
School
|
Educational Institution
|
4.0
|
6
|
|
N21
|
North Point
|
Provident Centre, Block 1
|
Residential
|
4.0
|
25
|
|
N22
|
North Point
|
Provident Centre, Block 6
|
Residential
|
4.0
|
25
|
|
N23
|
North Point
|
Provident Centre, Block
17
|
Residential
|
4.0
|
25
|
|
P1-A
|
Tin Hau
|
Planned location for
Re-provisioned Tin Hau
Temple (West Facing
Façade)
|
Temple
|
3.6
|
1
|
|
P1-B
|
Tin Hau
|
Planned location for
Re-provisioned Tin Hau
Temple (South Facing
Façade)
|
Temple
|
3.6
|
1
|
|
P2
|
North Point
|
A land zoned as “CDA(1)”
near Oil Street
|
CDA(1)
|
4.0
|
53 *
|
|
P3
|
North Point
|
A land zoned as CDA near Oil Street
|
CDA
|
4.5
|
34 *
|
Note: * The assumed number of floors was based
on information provided by Planning Department on the maximum building heights
of 165 mPD for CDA(1) site and 100 mPD for CDA site (within 60m of the northwest boundary).
4.4.2
According to the relevant draft
Outline Zoning Plans for the Project, the land uses of most future developments
are commercial, recreational facilities, temple and open spaces. Recreational
facilities and open spaces are not defined as NSRs in accordance with Annex 13
of the EIAO-TM. According to the normal practices adopted for similar land uses
in Hong Kong (e.g. existing HKAPA, Visitor
Centre of Hong Kong Wetland Park), the commercial buildings, HKAPA Extension
and the Harbour Education Centre would be provided with central
air-conditioning system and they do not rely on openable window for
ventilation. Thus, no adverse noise impact upon these premises would be
expected and, therefore they are not selected for traffic noise impact
assessment. One
future NSR, a re-provisioned Tin
Hau Temple
(NSR P1) that is located near Hing
Fat Street, has been identified.
4.4.3
Based on the North Point
Outline Zoning Plan No. S/H8/21, the areas in between Harbour
Heights and City Garden
have been zoned as Comprehensive Development Area (1) and Comprehensive
Development Area. “Flat” use has been added to Column 2 of the Notes of the
“CDA(1)” zone to allow flexibility for residential use. For the land zoned as
CDA, according to the revised Planning Brief for the site, residential use
should be set back from the Island Eastern Corridor (IEC) for 50m with non-noise sensitive uses to
screen the residential use. Based on information on the maximum building height
requirements provided by Planning Department, a notional point (NSR P2)
representing a 53-storey residential building at CDA(1) site has been assumed
on the demarcation line as indicated on the OZP, while a notional point (NSR
P3) representing a 34-storey residential building at CDA site has been assumed
at 50m setback from the
IEC.
4.4.4
The staff quarters of FEHD Depot
(i.e. NSR 15) and re-provisioned Tin Hau Temple
(i.e. NSR P1) are the nearest existing and planned NSRs to the louvers of
proposed East Ventilation Building
with a buffer distance of about 115m
and 250m, respectively. Existing receivers in the vicinity of the central
ventilation building such as the Hong Kong Academy for Performing Arts (HKAPA)
and the Arts Centre are provided with central air conditioning and do not rely
on the openable window for ventilation, and their indoor noise environment
would not be affected. As a result,
NSR 15 and NSR P1 have been selected for the noise assessment of East Ventilation
Building. For the purpose
of land use planning, the minimum buffer distances between the NSR and the
proposed East and Central
Ventilation Buildings
would also be identified.
4.4.5
To evaluate the noise from the
proposed permanent helipad and re-provisioned PTI, Causeway Centre (i.e. NSR
N2) which is closest to the helipad and PTI has been identified as
representative NSR for noise assessments.
Construction Noise During
Unrestricted Hours
4.5.1
The Project is scheduled to be
commenced in early 2009 and to be completed in 2016. According to the construction programme,
there are eight major construction tasks (as shown in Appendix 2.5). Some
individual tasks have different stages.
Table 4.6 summarises the
different tasks and phasing. All construction tasks are planned to be carried
out during unrestricted hours. Figure 3.4 shows
the locations of work sites.
Table
4.6 Summary
of Construction Tasks and Stages
|
Item
|
Tasks and Stages
|
Construction Period
|
Main Construction
Elements
|
|
1
Causeway
Bay Reclamation
|
|
1.1
|
Temporary Relocation Causeway
Bay Typhoon Shelter(CBTS)
|
January 2009 to February
2016
|
Temporary Breakwater
Relocation Mooring to
Temporary CBTS
Relocation Mooring back
to CBTS
|
|
1.2
|
CBTS Temporary
Reclamation Stage 1
|
August 2009 to May 2012
|
Dredging, temp seawalls and
filling (TCBR1)
CWB Tunnel (TCBR1)
CWB Tunnel (Cross Harbour Tunnel)(CHT)
|
|
1.3
|
CBTS Temporary
Reclamation Stage 2
|
November 2009 to May 2012
|
Dredging, temp seawalls
and filling (TCBR2)
CWB Tunnel (TCBR2)
|
|
1.4
|
CBTS Temporary Reclamation
Stage 3
|
January 2011 to April
2014
|
Dredging, temp seawalls
and filling (TCBR3)
CWB Tunnel (TCBR3)
|
|
1.5
|
CBTS Temporary
Reclamation Stage 4
|
May 2012 to November 2015
|
Dredging, temp seawalls
and filling (TCBR4)
CWB Tunnel (TCBR4)
|
|
1.6
|
Temp Diversion of Cooling Water System
|
October 2010 to
January 2016
|
|
|
1.7
|
Promenade along CBTS
|
November 2015 to March 2016
|
|
|
1.9
|
Slip Road & Victoria Park Reprovisioning
|
August 2013 to
March 2015
|
Victoria Park Road Traffic Division
Slip Road 8 &Tunnel
Transplant Trees in Victoria Park
At-grade Road, Landscaped deck
Reinstate Landscape work in VP
|
|
2
Ex-PCWA Temporary Reclamation
|
|
2.1
|
Temporary Reclamation PCWA Stage 1
|
February 2009 to
May 2012
|
Dredging, Filing and
Seawall (PCWAE)
CWB Tunnel (PCWAE)
|
|
2.2
|
Temporary Reclamation PCWA Stage 2
|
March 2012 to
May 2015
|
Dredging, Filing
and Seawall (PCWAW)
CWB Tunnel (PCWAW)
|
|
3
Wan Chai Reclamation
|
|
3.1
|
Wan Chai Reclamation
Stage 1
|
January 2009 to February
2011
|
Dredging, Seawalls and
Filling
Drainage Culverts
Cooling Water Syetem
CWB Tunnel(WCR1)
|
|
3.2
|
Wan Chai Reclamation
Stage 2
|
January 2011 to May 2013
|
Dredging, Seawalls and
Filling
CWB Tunnel
Promenade
|
|
3.3
|
Wan Chai Reclamation
Stage 3
|
April 2011 to March 2015
|
Dredging, Seawalls and
Filling
CWB Tunnel
Promenade
|
|
3.4
|
Wan Chai Reclamation
Stage 4
|
October 2012 to March
2015
|
Dredging, Seawalls and
Filling
Drainage Culverts
CWB Tunnel
Promenade
|
|
3.6
|
Ferry Pier Reprovisioning
|
February 2009 to May 2011
|
Temporary Ferry Piers
New Ferry Piers
|
|
3.7
|
Helipad Reprovisioning
|
January 2009 to June 2010
|
Reprovisioning at HKCEC
|
|
3.8
|
Sewage Outfall
|
October 2009 to
April 2011
|
Marine Section – Submarine
Pipelines
Land Section – New
Pipeline
|
|
3.9
|
WSD’s Salt Water Pumping
Station
|
February 2009 to October
2010
|
Construct New Pumping
Station
|
|
3.10
|
Roads
|
October 2014 to September
2015
|
Road P2
|
|
4
HKCEC Reclamation
|
|
4.1
|
HKCEC Reclamation Stage 1
(Water Channel)
|
January 2009 to
April 2016
|
Dredging, Seawalls and
Filling
Cooling Water Systems
CWB Tunnel
|
|
4.2
|
HKCEC Reclamation Stage 2
|
January 2009 to March
2014
|
Dredging, Seawalls and
Filling
Drainage Culverts
CWB Tunnel
|
|
4.3
|
MTR Tunnel Crossing
|
October 2010 to February
2012
|
Piling for Tunnel Units
and Deck
Tunnel and Deck
Construction
|
|
4.4
|
HKCEC Reclamation Stage 3
|
March 2011 to October
2013
|
Dredging, Seawalls and
Filling
Drainage Culverts
CWB Tunnel
|
|
4.5
|
Roads
|
March 2014 to November
2015
|
Road P2
|
|
5
Cross Harbour Watermains
|
|
5.1
|
Submarine Pipeline
|
January 2009 to September
2010
|
Lay New Submarine
Pipeline
|
|
5.2
|
Lands Sections
|
September 2009 to May
2010
|
Lay Land Piplines
HKCEC
|
|
6.0
North Point Reclamation
|
|
6.1
|
North Point Reclamation
Stage 1
|
January 2009 to October
2010
|
Dredging, Seawalls and
Filling
CWB Tunnel (NPR1)
|
|
6.2
|
North Point Reclamation
Stage 2
|
April 2009 to November 2012
|
Dredging, Seawalls and
Filling (NPR2E, NPR2W)
CWB Tunnel (NPR2W)
|
|
6.3
|
Promenade
|
August 2016 to December
2016
|
Promenade (NP) Final
|
|
7.0
Construction of Island Eastern
Corridor Link (IECL)
|
|
7.2
|
IEC Connection Work
|
October 2010 to May 2016
|
IEC East Bound (E/B) (HFS
to Mainline)
IEC E/B Traffic Diversion
Reconstruction IEC West
Bound(W/B)
IEC W/B Traffic Diversion
Mainline Connection to
IEC
|
|
7.3
|
East Portal and IEC
Connection
|
May 2015 to August 2016
|
Portal Construction
Traffic Diversion IEC E/B
|
|
10
|
Tunnel Building and
Installation
|
November 2011 to May 2016
|
|
|
10.1
|
East Ventilation Building
|
November 2012 to
September 2013
|
Superstructure of the
Building
E&M Work
|
|
10.2
|
Administration Building
|
February 2015 to November
2015
|
Substructure of the
Building
Superstructure of the
Building
E&M Work
|
|
10.3
|
Central Ventilation Building
|
January 2014 to January
2015
|
Substructure of the
Building
Superstructure of the
Building
E&M Work
|
4.5.2 The maximised use of public fill is proposed in the reclamation and
the construction noise assessment is based on this construction programme and
associated plant use. In
considering the alternative greater use of sand fill, the public fill scenarios
will require more noise generating plant use over longer periods of time and,
in overall terms, the assessment that has been undertaken can therefore be
considered to represent the worst case reclamation method.
4.5.3 The construction noise assessment has been carried out on a monthly
basis from the commencement of the Project. The construction tasks of the
Project taking place concurrently within 300 m of a given NSR are considered to
contribute to the cumulative impact at that NSR. Noise sources from the areas greater
than this distance have been excluded from the assessment.
4.5.4 In accordance with the EIAO, 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. Where no SWL was supplied in the GW-TM,
reference was made to BS 5228, previous similar studies or from measurements
taken at other sites in Hong Kong. Schedule of
powered mechanical equipment (PME) for the different construction tasks during
normal daytime working hours is presented in Appendix 4.5.
4.5.5 In view of the anticipated adverse noise impact at the NSRs in the
vicinity of Causeway Bay and North Point reclamation areas due to the limited
buffer distance, appropriate on-time percentage for some items of PME,
including poker vibrator, crane, excavator and tug boat, dump truck and backhoe
were reasonably assumed as presented in Appendix
4.5. Besides, instead of percussive piling, bored piling would be deployed
in order to minimise the construction noise impact. The Civil Engineering and
Development Department (CEDD) and the Highways Department (HyD) have confirmed
that it is practicable and feasible in the context of the construction
programme (see Appendix 15.1).
4.5.6 During demolition of the IEC, as the existing elevated IEC
superstructures are made of precast U-beams, the practical demolition method is
to break the two ends at the piers, separate the U-beams and lift the U-beams
by crane. Conventional construction method with mechanical breakers such as
excavator mounted breakers etc. has been adopted for the construction noise
assessment. While alternative construction method such as saw cutting may be
used in localised areas for cutting the slabs to separate the U-beams for
removal by lifting one by one, excavator
mounted breakers with sound-proof hammer bracket or hydraulic breaker will be
used in any case to break the pier head for the connection with the reconstructed
IEC. Alternative demolition plant such
as hydraulic crushers have been considered, however,
hydraulic concrete crusher has limited jaw opening width which is suitable for
demolition of walls in buildings or parapets along the bridge deck in this case
but not U-beams for highway structures. The use of saw cutting and hydraulic
concrete crusher will be used locally for specific demolition works wherever
applicable to minimise the construction noise impact. However, from a practical
engineering viewpoint, conventional construction method
with excavator mounted breakers with sound-proof hammer
bracket or hydraulic breaker, which have to be deployed in any case for the IEC demolition work, has been adopted for construction noise assessment for a prediction
of reasonable worst case scenario.
4.5.7
It was 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 was divided into groups required for
each discrete construction task.
The objective was 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 was calculated, depending on the number of plant and distance
from receivers. The noise levels at
NSRs were then predicted by adding up the SWLs of all concurrent construction
tasks.
4.5.8
A positive 3 dB(A) façade
correction was added to the predicted noise levels in order to account for the
façade effect at each NSR. The
boundary walls around HKAPA Open Arena are assumed as noise barriers and a 5
dB(A) reduction of the predicted noise levels at receiver N1 is expected due to
the shielding effect.
4.5.9
The CRIII project has already
commenced and is scheduled to be completed in September 2012. Besides, the Hong Kong Convention and
Exhibition Centre, Atrium Link Extension (HKCEC ALE) project is scheduled to
commence in May 2006 and to be completed in March 2009, according to the EIA Report for HKCEC ALE (March
2006). Therefore, some construction
tasks of the CRIII and HKCEC ALE projects will be carried out within the same
construction period of the Project.
The following construction activities of these projects will overlap
with the Project:
l
CRIII Project
l
CWB under CRIII main contract
(December 2008 – March 2012)
l
Drainage Culverts (October 2008
– September 2012)
l
Roadworks (October 2008 –
September 2012)
l
HKCEC ALE Project
l
Remove marine piles for working
platform (October 2008 – November 2008)
l
Demolish temporary footbridge
(December 2008 – February 2009)
l
Remove marine piles for
temporary footbridge (January 2009 – March 2009)
4.5.10 The PMEs for CRIII project with mitigation measures, as shown in Appendix 4.6, were made with reference
to the EIA Report for CRIII. Besides, in accordance with the EIA Report for HKCEC ALE, the maximum
SWL of the construction activities throughout the construction period would be
estimated to be about 127 dB(A). The noise data from these two studies was
adopted to calculate the cumulative construction noise impact in this EIA
study.
Construction Noise During
Restricted Hours
4.5.11 The construction programme for the Project takes into account the
likelihood that the contractor will, if permitted, undertake dredging and
seawall construction works over a 16-hour working day (0700 to 2300 hours) at
the area of PCWA, Wan Chai Reclamation and HKCEC Reclamation. This is in order
to maintain his required work rates to meet the tight programme with some
allowance for plant downtime, variability in fill supply rates, etc. The longer
working hours will also ensure that allowance can be made to cater for possible
changes in dredging and filling rates due to deterioration of water
quality. Land-based construction
activities, on the other hand, will generally be carried out over a 10-hour
working day (0800 to 1800 hours). However, where necessary, for example to
minimise traffic impacts due to road diversion works, diversion of salt water
intake back to existing system in WSD’s salt water pumping station and
construction of drainage culverts in the existing built up hinterland, construction works during restricted
hours may be required.
4.5.12 The following key activities may require construction noise permits
for night work.
(i)
Marine-based construction activities:
(ii)
dredging of reclamation areas
and seawalls
(iii)
seawall trench filling
(iv)
seawall construction
(v)
filling behind seawalls
Land-based plant
activities:
(i)
construction of new drainage
culverts in the hinterland urban area
(ii)
diversion of existing cooling
water mains through the hinterland area
(iii)
diversion of salt water intake
and pumping mains along existing roads
(iv)
construction of upgraded
sewerage pipelines along existing roads
(v)
construction of new water mains
along existing roads
(vi)
connections for water, sewage
and cooling water mains
(vii)
traffic diversion works for new
road construction
4.5.13 According to GW-TM, for any construction works planned during the
restricted hours, the Contractor will be required to apply for a CNP from the Noise
Control Authority and has the responsibility to ensure compliance with the NCO
and relevant TM. Therefore, an
indicative noise assessment in this EIA is for the evaluation of whether
construction works in restricted hours are feasible or not in the context of
programming construction work only. Detailed discussion is presented in Section
4.10.
Operational Phase – Road
Traffic Noise
4.5.14 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 2016. Therefore,
the traffic data for year 2031, which has been endorsed by Transport Department
(see Appendix 15.1), was adopted for
the assessment. Since traffic flows
along the major roads during the peak hour in the morning are generally higher
than that in the afternoon, the morning peak hour traffic flows were used for
modelling. The projected 2031 am
peak hour traffic flows are presented in Appendix
3.2.
4.5.15 Traffic speeds for the proposed Trunk Road system adopted in the
noise model are summarised as follows:
Road
Speed
Limit
Trunk Road (Open Section
& Underneath Landscaped deck) 70 km per hour
Trunk Road in Tunnel 80
km per hour
Road P2 50
km per hour
Slip Roads 50 km per hour
Operation Roads 50
km per hour
4.5.16 The traffic speed for all existing roads has been made reference to
the Traffic Aids provided by Transport Department. Based on information
provided by Highways Department, low noise road surface on the existing Island
Eastern Corridor as shown in Figure 4.8 has
been included in the noise model. Besides, low noise road surface has been
assumed for the proposed trunk road (except tunnel section and beneath the
landscaped deck at the eastern portal area) with speed limit of 70 km/hour.
4.5.17 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. Hard ground as defined in CRTN was
assumed throughout the Study Area.
Noise levels were calculated at each receiver point at various
elevations.
4.5.18 Two ventilation buildings for the CWB tunnel, East Ventilation
Building (EVB) and Central Ventilation Building (CVB), are proposed along the
CWB within the WDII study area. The CVB will contain its ventilation shaft at
the same location. The EVB would be located at the North Point waterfront,
while its ventilation shaft would be located at the CBTS eastern breakwater.
Fans and damper arrangement at each ventilation building may be refined in
detailed design.
4.5.19 Potential noise impacts arising from the operation of ventilation
fans would be expected at the sensitive receivers, and this fixed plant noise
impact has been assessed in accordance with the IND-TM.
4.5.20 As the worst case scenario, the assessment has been carried out for
the congestion mode when the maximum number of ventilation fans would be in
operation. According to information provided by the Ventilation Engineer, 7
duty plus 2 standby ventilation fans are proposed for EVB, while 11 duty plus 2
standby ventilation fans are proposed for CVB. Table
4.7 summarises the numbers of ventilation fans required for proposed
ventilation buildings under congestion condition.
Table
4.7 Number
of Ventilation Fans required for the Proposed Ventilation Buildings under
Congestion Condition
|
Ventilation Building
|
Fan Capacity (m3 s-1)
|
Number of Ventilation
Fans Required
|
|
East Ventilation Building
|
125
|
|
|
Central Ventilation Building
|
125
|
11 (+2 standby)
|
4.5.21 It is assumed in the assessment that all duty ventilation fans are
operated at each ventilation building.
Screening corrections from other buildings / structures and directivity
have also been excluded in the assessment. All the ventilation fans installed
in each ventilation building will be provided with silencers. The typical
length of the silencer proposed for ventilation fan will be 3,000 mm. A positive 3 dB(A) tonality
correction was considered in the calculation.
PTI Noise
4.5.22 The re-provisioned PTI will be located to the north of Causeway
Centre and Sun Hung Kai Centre, and the site is currently occupied as Harbour
Road Sport Centre and a open carpark. The PTI will be implemented with the
construction of the Exhibition Station for North Hong Kong Island Line/Shatin
to Central Link.
4.5.23 As the layout and operational details of the re-provisioned PTI is
not available at the time of carrying out this EIA, a qualitative approach
would be adopted to address the noise nuisance arising from the operation of
the PTI.
Helicopter Noise
4.5.24 The proposed permanent helipad will be located next to the HKCEC
Extension. It has been confirmed by
Government Flying Service that the operation parameters for the proposed
helipad, which was adopted in the previously approved EIA Report on Wan Chai Development Phase II, are still valid for
this EIA study (see Appendix 15.1).
It will be used to serve VIPs as well as for emergency services and, therefore,
will be used infrequently. Routine tasking or regular flights are not expected.
Only the new types of helicopter, Eurocopter AS-332 L2 (Super Puma) and Eurocopter EC 155B, will
operate at the proposed helipad.
4.5.25 As stated in the aforesaid EIA Report, there will be no designated
approach route and take-off route for the proposed helipad. However, the helicopters will generally
fly along the coastline to approach the landing pad.
4.5.26 With reference to the Final
EIA Study for Helipad at Yung Shue Wan, Lamma Island (approved in January
2006), the measured Lmax for EC 155B and AS 332 L2 are 87.7 dB(A) and 90.6 dB(A) respectively at
reference distance of 150m.
Therefore, this assessment has been undertaken based on the noise level
associated with an AS 332 L2
helicopter as a conservative approach.
4.5.27 The closest NSR (i.e. Causeway Centre) to the helipad has been
selected for assessment. The calculation is based on the spherical spreading of
the sound waves and atmospheric absorption was not considered.
4.5.28 It is understood that the proposed permanent helipad might also be
used for commercial helicopter services based on the principle that government
operations shall have absolute priority in the use of helipad over commercial
operations at all times.
4.5.29 The helicopter noise is controlled under the Civil Aviation
(Aircraft Noise) Ordinance, for which, Civil Aviation Department is the control
authority.
Level of Uncertainty
4.5.30 The predictions of construction and road traffic noise impacts were
based on the methodologies described in the GW-TM under the NCO and the UK Department
of Transport “Calculation of Road Traffic Noise” (1988) respectively. The methodology which had previously
been applied in other EIA studies is generally accepted for use in assessing
construction and traffic noise impacts against EIAO-TM noise criteria.
4.5.31 There would be some limitations such as the accuracy of the
predictive base data for future conditions e.g. traffic flow forecasts, plant
inventory for the proposed construction works and fixed plant for future
operation. Uncertainties in the assessment of impacts have been considered when
drawing conclusions from the assessment.
4.5.32 In carrying out the assessment, realistic worst case assumptions
have been made in order to provide a conservative assessment of noise
impacts. The construction noise
impact was assessed based on conservative estimates for the types of plant and
methods of working. As for the
assessment of road traffic noise impact, peak hourly traffic flows representing
the worst case scenario were adopted.
4.5.33 For ventilation noise assessment, being the worst case scenario, the
assessment has been carried out for the congestion mode when the maximum number
of ventilation fans would be in operation. All duty ventilation fans have been
assumed to operate concurrently 24 hours daily. For determining the distance
correction factors, the horizontal distances between the noise source positions
and the NSRs were used for representing the worst level of the representative
NSRs.
4.5.34 For helicopter noise assessment, the operation parameters for the
proposed helipad, which was adopted in the previously approved WDIICFS EIA
Report, have been adopted for this EIA study. With reference to the noise data
in Final EIA Study for Helipad at Yung
Shue Wan, Lamma Island (approved in January 2006),
this assessment has been undertaken based on the noise level associated with an
AS 332 L2 helicopter as a
conservative approach.
Construction Phase
4.6.1
The scope of this Project
includes reclamation; construction of the trunk road and Road P2 and associated
connecting roads and local access roads, construction of CVB and EVB and Administration Building. Potential construction impacts of the
Project may arise from the following activities:
l
dredging works and seawall
construction
l
filling behind seawall
l
reprovisioning of ferry pier
l
road formation and earthworks,
and road pavements
l
tunnel construction
l
drainage culvert construction
4.6.2
The construction works for the
CRIII project and HKCEC ALE project would also contribute to the cumulative
construction noise impacts.
4.6.3
Drilling and breaking method would be adopted for the tunnelling works
for the Trunk Road section crossing beneath the Cross Harbour Tunnel, while cut-and-cover method would be adopted for the rest of the
tunnel sections. The ground-borne construction noise is only addressed for the
tunnelling work near the Cross Harbour Tunnel because it is the only section
that would have underground drilling and breaking. The tunnelling work at other
sections would be exposed and the dominating noise would be the air-borne
construction noise that would be assessed separately in this EIA.
4.6.4
With reference to an EIA Report
on KCRC Kowloon Southern Link, a ground-borne noise assessment on the hydraulic
breaker was presented. Four hydraulic breakers working at a distance of around 22m in rock media would produce around 30
dB(A) ground-borne noise inside the Studio Theatre of the Hong Kong Cultural
Centre. This noise level was well below the noise criterion of 65 dB(A) and
hence the ground-borne noise impact generated by hydraulic breaker was not
significant. In this regard, the ground-borne noise impact of rock breaking
activity on the most affected noise sensitive receivers (Hoi Kung Court, Hoi To Court and Hoi Deen Court at Gloucester Road)
would be minimal, taking into account the buffer distance of more than 150m.
Operational Phase
4.6.5
Operational phase impacts will
arise from the following operations:
l
road traffic noise
l
ventilation noise
l
Public Transport Interchange
(PTI)
l
helicopter noise
4.6.6
Road traffic noise will arise
from new roads constructed under the Project as well as the existing roads.
4.6.7
Ventilation noise affecting
sensitive receivers in the study area may arise from the proposed ventilation
buildings under the Project (i.e. CVB and EVB). A re-provisioned PTI located to the
north of Causeway Centre and Sun Hung Kai Centre may have potential noise
impact on the nearby sensitive receivers.
4.6.8
Potential noise impacts may
arise from the permanent helicopter landing pad which is proposed at the
northeast of HKCEC Extension.
Construction Noise During
Unrestricted Hours
4.7.1
For normal daytime working
hours, exceedences of the construction noise criteria (Leq (30 minutes)
75 dB(A) for residential uses and 70 dB(A) for educational institutions (65
dB(A) during examinations)) are predicted at representative NSRs in the absence
of mitigation measures. Details of
construction noise calculations and results are presented in Appendix 4.7. Results show that the predicted noise
levels related to the concurrent construction works of the Project, CRIII and
HKCEC ALE projects are in the range of 57 to 101 dB(A) Leq (30-min). 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 4.8. Noise mitigation
measures would therefore be required to reduce noise levels to the stipulated
standard.
Table
4.8 Summary
of Unmitigated Construction Noise Levels at Representative NSRs During Normal Daytime Working Hours
|
Representative
NSRs
|
Predicted
Unmitigated Construction Noise Levels during Normal
Daytime Working Hour (Leq (30-min) dB(A))
|
|
N1
|
67 - 81
|
|
N2
|
67 - 83
|
|
N3
|
62 - 79
|
|
N6
|
68 - 78
|
|
N8
|
65 - 85
|
|
N11
|
57 -101
|
|
N13
|
60 - 84
|
|
N15
|
66 - 88
|
|
N17
|
63 - 96
|
|
N18
|
62 - 98
|
|
N20 #
|
65 - 90
|
|
N22
|
64 -79
|
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.
4.7.2
The proposed cross harbour
water mains will extend from Wan Chai near the HKCEC Extension to connect to the
existing system near the Museum of Arts at the Tsim Sha Tsui
promenade. The major construction
activities include laying new submarine and landside pipelines. These are not major noise generating
activities. The NSRs close to the
construction sites at Wan Chai and Tsim Sha Tsui are the HKCEC Extension, the Hong Kong Space
Museum and the Museum of Arts. Since they have blank façades / fixed
windows and are provided with central air conditioning (i.e. they do not rely
on openable windows for ventilation), there will be no construction noise
impacts on the indoor environment of these NSRs.
Road Traffic Noise
4.7.3
Traffic noise levels have been
predicted at a total of 31 representative noise assessment points including existing residential
dwellings, institutional uses, re-provisioned temple and future uses on land
zoned as CDA(1) an CDA. Noise screening effect of a landscaped deck connecting
the eastern portal of the CWB tunnel (see Figure 4.6),
being a built-in design of the Project, has been taken into account for the
assessment. In view of the visual quality, south-facing panel of the landscaped
deck would be installed with transparent material. Appendix 4.8 gives the breakdown of the noise contributions from
the new roads and existing roads at all representative existing and planned
NSRs. Sample output files for 10 representative assessment points, as agreed
with the EPD, are included in Appendix
4.9. Road-plots of the traffic noise model are included in Appendix 4.9a.
4.7.4
Without the noise mitigation
measures in place, the predicted noise levels at the identified NSRs would
range from 60 to 87 dB(A) L10 (1-hour). The following paragraphs
discuss the potential noise impacts at each broad group of NSRs under study.
Wan Chai Area (NSRs N1 –
N5)
4.7.5
For the open arena of HKAPA,
the performance area is set at the lowest level with tiered seating for the
audience. Given the existing 2.5m
high barriers surrounding the open arena, the predicted noise level of 60 dB(A)
at N1 would comply with the noise limit of 65 dB(A). On the other hand, noise
exceedences by 2 to 17 dB(A) are predicted at NSRs N2 to N5. Noise exceedences at NSRs N2 to N5 are
mainly attributed to the existing roads (i.e. Harbour Road and Gloucester Road). The noise levels of
‘New’ roads would be less than 70 dB(A) and their contribution to the overall
noise levels would be less than 1.0 dB(A). Direct mitigation measures on ‘New’
roads are therefore not required as they would not be effective in improving
the noise environment at the sensitive receivers.
Causeway Bay Area
(NSRs N6 – N8)
4.7.6
The predicted noise levels at
N6 to N8 exceed the noise criterion of 70 dB(A) by 8 to 15 dB(A). However, the
noise exceedences are caused by the existing roads. As the new road in front of these NSRs
will be mainly constructed in the form of tunnel, the ‘New’ road noise
contribution to the overall noise level would be less than 1.0 dB(A) and the
‘New’ road noise levels at these NSRs would all be below 70 dB(A). Hence, direct mitigation measures on
‘New’ roads are not required as they would not be effective in improving the
noise environment at the sensitive receivers.
Tin Hau Area (NSRs N9 –
N17, P1-A and P1-B)
4.7.7
The predicted noise levels at
N9 to N17 exceed the noise criterion of 70 dB(A) by 1 to 11 dB(A), while the
predicted noise level at P1-A and P1-B (i.e. re-provisioned Tin Hau Temple) exceed the noise criterion of 65
dB(A) by up to 7 dB(A). With the exception of N16, N17 and N17-A, the noise
exceedences at other NSRs (i.e. N9 to N15) are mainly attributed to the
existing roads, while the ‘New’ road noise contribution to the overall noise
level would be less than 1.0 dB(A) and the ‘New’ road noise levels at these
NSRs would all be below 70 dB(A). Hence, direct mitigation measures on ‘New’
roads would be required for N16, N17 and N17-A.
4.7.8
While the noise levels of ‘New’
roads at the re-provisioned Tin Hau Temple (NSRs P1-A and P1-B) would be less
than 65 dB(A) and their contribution to the overall noise levels would be less
than 1.0 dB(A), placing planned NSR near busy road which would be subject to
traffic noise levels exceeding EIAO-TM noise limit should be under more
scrutiny from Schedule 3 EIA land use planning perspective. Given no
alternative site could be identified for this temple at this stage, mitigation
measure at the temple will be considered and examined.
North Point Area (NSRs
N18 – N23, P2 and P3 )
4.7.9
The predicted noise levels at
N18 to N19 and N21 to N23 exceed the noise criterion of 70 dB(A) by 3 to 11
dB(A), while the predicted noise level at N20 (i.e. Hong Kong Baptist
Church Henrietta
Secondary School) exceeds
the noise criterion of 65 dB(A) by 12 dB(A). With the exception of N21 to N23, the
‘New’ road noise contributions to the overall noise levels at other NSRs
(i.e.N18 to N20) would be more than 1.0 dB(A) and the ‘New’ road noise levels
at these NSRs would be above 70 dB(A) for residential dwellings and 65 dB(A)
for educational institutions. Hence, direct mitigation measures would be required
to reduce the noise impact from ‘New’ roads for NSRs N18 to N20.
4.7.10 The ‘New’ road noise contributions to the overall noise levels at
planned NSRs (i.e. P2 and P3) would be more than 1.0 dB(A) and the ‘New’ road
noise levels at these two NSRs would be above 70 dB(A) for residential
dwellings. Hence, direct mitigation measures would be required to reduce the
noise impact.
Ventilation Noise
4.7.11 Since the ventilation fans are expected to operate 24 hours daily,
referring to Table 4.4, the calculation is based on the stringent fixed noise
night-time criteria of 50/55 dB(A) Leq (30-min) in the assessment
according to EIAO-TM requirement. It is assumed in the assessment that all duty
ventilation fans would be operated for each ventilation building. As the two
proposed ventilation buildings are quite far away from each other, no
cumulative fixed noise impact is determined in this case.
4.7.12 Taking into account the installation of silencers at each
ventilation fan, any NSRs located within the following distances from the
ventilation louvres of EVB and CVB would be subject to an exceedence of the
noise criteria of 50/55 dB(A). Detailed assessment results are presented in Appendix 4.10.
Ventilation Building Distance from the ventilation louvres (m)
ASR ‘B’ ASR
‘C’
EVB 119 67
CVB 149 84
4.7.13 Land uses around these two proposed ventilation buildings, within
these zones of noise criteria exceedence, are commercial, infrastructural or open
space. The staff quarters of FEHD Depot (NSR 15) and re-provisioned Tin Hau
Temple (NSR P1) are
located about 115m
and 250m away from the
sea-facing louvres of EVB respectively, while the open arena of HKAPA is
located about 190m
away from the louvers of CVB. Thus, no adverse ventilation noise impacts would
be expected. From a land use planning point of view, new land uses in this area
should take these zones of noise exceedence into account.
4.7.14 According to current planning intentions, the proposed ventilation
building for the MTR North Island Line (NIL) would be located near the junction
of Fleming Road
and Convention Ave,
and it would be about 300m
away from the CVB. The nearest NSR relying on openable window for ventilation
(i.e. Causeway Centre) is located at more than 500m from CVB and about 270m from the ventilation building of NIL. Also,
ventilation noise would be substantially screened by the buildings in between
the ventilation buildings and Causeway Centre. Thus, no adverse cumulative
fixed noise impacts of both ventilation buildings would be expected. Further,
it is noted that the proposed NIL has to undergo a statutory EIA and it is
expected that the noise level generated from the ventilation fans would comply
with the EIAO-TM and NCO requirements.
PTI
Noise
4.7.15 A re-provisioned PTI would be located to the north of Causeway
Centre and Sun Hung Kai Centre. The site is currently occupied by Harbour Road
Sport Centre, Wan Chai Training Pool and open carpark. It is expected that the
major potential noise impact arising from the operation of the PTI would be the
noise nuisance from bus engine in particular during night-time and early
morning affecting the adjoining high-rise building. Causeway Centre, which is
about 82m away from the
geographical centre of the re-provisioned PTI, has been identified to be the
nearest affected NSR. Assuming the operational scale of the re-provisioned PTI
is similar to that of the existing Wan Chai North PTI, potential noise issues
are likely at Causeway Centre if no control measures are applied.
Helicopter Noise
4.7.16
With reference to basic
acoustic principles and based on the measured noise level for a AS 332 L2 helicopter, a setback distance of
about 286m to the nearest
residential premises is required in order to meet the EIAO-TM noise standard of
85 dB(A) Lmax (domestic premises) for helicopter noise (see Appendix 4.12). It is
noted that for the EC 155B helicopter, which is quieter than the AS 332 L2 helicopter, lesser set-back
distances from the proposed helipads would be required. The distance between
the permanent helipad and the closest residential NSR (Causeway Centre) is
about 530m, therefore it is
considered that the proposed helipad locations would be acceptable in terms of
noise levels.
4.7.17 It is understood that the proposed permanent helipad might also be
used for commercial helicopter services based on the principle that government
operations shall have absolute priority in the use of helipad over commercial
operations at all times. At this stage, it would be difficult
to make the assumptions (e.g. frequency of flights, type of helicopters, etc.)
of commercial helicopter services for noise assessment. However, in view of the
considerable buffer distance between the NSRs and the helipad (i.e. about 530m), adverse helicopter noise impact would
not be anticipated. Furthermore, CEDD has separately commissioned a detailed
helipad assessment, which includes noise assessment to
prepare an optimal layout for helipad and to avoid adverse helicopter noise impact. Noise mitigation measures proposed
under the separate study includes a noise barrier of 6m high around the landward side of the helipad site, although it is noted that this is still subject to the endorsement under that study.
Other
Fixed Noise Sources
4.7.18 Other existing fixed noise sources identified within 300m of the proposed CVB include Wanchai
West Sewage Screening Plant and Kwong Wan Fire Station. According to the
relevant draft Outline Zoning Plans for the Project, Wanchai West Sewage
Screening Plant will be demolished and replaced by the Hong Kong Academy of
Performing Arts Extension. The nearest NSR relying on openable window for
ventilation (i.e. Causeway Centre) is located at more than 300m from the fire station and CVB, and
the re-provisioned PTI will be more than 300m
away from the fire station and CVB. Thus, no adverse cumulative fixed noise
impact would be expected.
4.7.19 Other existing fixed noise sources identified within 300m of the proposed EVB include Tung Lo
Wan Fire Station, electric sub-station near Whitfield
Road Rest
Garden and open car/lorry park along
the waterfront and near Harbour
Heights. According to the
relevant draft Outline Zoning Plans for the Project, open car/lorry park along
waterfront will be replaced by a waterfront park. The fixed noise sources (i.e.
Tung Lo Wan Fire Station, electric sub-station and open car/lorry park near Harbour Heights) are located in the range of 175m to 275m away from the proposed EVB. Given the total Sound
Power Level (SWL) of 96.5 dB(A) for the ventilation fans of EVB, the predicted
noise level at the nearest NSR (i.e. staff quarters of FEHD Depot – about 115m from sea-facing louvers of EVB)
would be 50 dB(A) which is 5 dB(A) below the night-time noise limit of 55
dB(A). As such, it is anticipated
that noise contribution from the proposed EVB to the cumulative fixed noise
impact would not be significant.
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,
movable noise barriers and temporary noise barriers are recommended. The above mitigation measures have been
vetted and confirmed by the CEDD and HyD 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 website
of EPD, and the PME are known to be available in Hong Kong.
The quiet PME adopted for the CRIII construction tasks are in accordance with
CRIII EIA Report.
4.8.3
The lists of quiet PME adopted
in the construction tasks of the Project during normal daytime working hours
are shown in Appendix 4.13. For the following
construction tasks of the Project, it is considered necessary to adopt quiet
PME:
l
Piling activity for
construction of temporary breakwater at Causeway Bay Typhoon Shelter
l
Temporary seawall construction,
filling behind seawall, for whole of WDII construction
l
Diaphragm wall, excavation,
construction of slabs and backfilling in CWB tunnel
construction
l
Rock excavation at CWB tunnel
(Cross Harbour Tunnel section)
l
Temporary diversion of cooling
water pipeline at CBTS 4
l
Slip Road 8
and Victoria Park Road
reprovisioning and at-grade road construction
l
Substructure and superstructure
for landscaped deck, connection of IECL
l
Demolition of structure,
including the IEC structure
l
Drainage culverts construction
l
Ferry pier
reprovisioning, including construction of new ferry
pier and demolition of existing structure.
l
WSD’s salt water pumping
station construction
l
Road works construction
l
MTR Tunnel crossing
l
Cross harbour watermains
l
Foundation of East Ventilation
Building
4.8.4
To alleviate the construction
noise impact on the affected NSRs, two types of noise barriers (movable and
temporary noise barriers during construction) 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 to 10 dB(A) noise reduction. Temporary noise barriers (5m in height) with cantilevered upper
portion (3.5m in length) are
also proposed in NPR2W, NPR1, NPR2E work sites along the diaphragm wall of the
tunnel section and retaining walls of the tunnel approach ramp for alleviation
of construction noise during construction of diaphragm walls and substructures
of the tunnel approach ramp. Temporary
noise barriers with height up to the soffit of the bridge deck area are proposed
along the existing IEC structure for alleviation of construction noise during
the demolition and construction of substructures for the IEC and construction
of adjacent tunnel approach ramp structures. Locations of the temporary noise
barriers are presented in Figure 4.9. A 10
dB(A) noise reduction can be achieved by eliminating the line of sight from the
receivers along the construction areas.
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.
4.8.5
Additionally, apart from the
temporary noise barrier as proposed and presented in Figure 4.9,
temporary noise barriers are also proposed on the temporary working platform on piers or pile
caps for the demolition works of existing piers and
crossheads for the marine section of the existing IEC.
Locations of temporary noise barriers are
presented in Figure 4.9a.
4.8.6
PME grouping as noise
mitigation measures would be implemented at NSR N11, N13 N17, N18 and N20. In
order to minimize the noise impact to the surrounding NSRs, either Group 1 or 2
would be operated at any one time under the construction schedule. Based on the
construction programme, at-grade road construction including reinstatement of
Victoria Park Road would be carried out for 8 months (i.e. 1-month works period
has been assumed at Hing Fat Street between Wing Hing Street & Tsing Fung
Street and associated road works at Wing Hing Street and Tsing Fung Street, the
closest distance between PME and NSR N11 is about 7m; and a 7-month works period has been assumed in the
area outside Hing Fat Street between Wing Hing Street & Tsing Fung Street
and associated road works at Wing Hing Street and Tsing Fung Street including
reinstatement of Victoria Park Road). Taking into account the site constraint
and commercial activities at the ground level alongside Hing Fat Street, movable and temporary
noise barriers would not be considered practicable for such at-grade roadworks.
4.8.7
Considering the noise impact arising from the demolition and construction
of superstructure would move along with the IECL construction programme, the
corresponding noise impact sections have therefore been identified and taken
into account in noise calculations. Figure 4.10 shows the corresponding impact sections (N17 – section 1 and 4; N18 – section 2 and 5; and N20 – section 3 and
6) during demolition works. Figure 4.10a shows the corresponding impact section (N17 – section C; N18 – section
B; and N20 – section A and D) during construction of superstructure works.
4.8.8
The shortest distance between the corresponding
noise impact sections and NSR would represent the worse case scenario and the duration of noise exceedance would also be calculated based on the
construction programme. Noise impact from adjacent
sections, other than the corresponding sections, would be decreased as the
construction programme progresses along the site and the noise level would be
complied with acceptable criteria. For NSR N18, land section and marine section
for one specific task (i.e. demolition of structure and construction of
superstructure and retaining structure) was assumed since different types and
numbers of PME with different sound power levels would be identified in this
assessment.
4.8.9
The mitigation measures for the
items of PME in each construction task have been shown in Appendix 4.13.
4.8.10 As shown in Appendix 4.14,
with the use of quiet equipment, movable / temporary noise barriers PME
grouping, the overall noise levels at NSRs would be reduced by 7 to 31 dB(A) Leq (30-hour), depending on the type of construction activities. With the
exception of NSRs N11, N17, N18 and N20, the predicted construction noise
levels arising from the Project at all other
NSRs selected for construction noise impact assessment would comply with the EIAO-TM construction noise criteria.
4.8.11 In view of the limited buffer distance between the NSRs and the
nearest work areas (N11 – 7m, N17 – 20m, N18 – 16m
and N20 – 42m), the predicated construction noise levels at
these NSRs would exceed the noise criteria. Practical mitigation measures (i.e.
use of quiet equipment, movable barriers, temporary barriers and PME grouping)
have been exhausted, taking into account the engineering and programming point
of view. For N11 (i.e. Mayson Garden),
the predicted noise level would exceed the noise standard of 75 dB(A) for 1 month
by 10 dB(A) with Group 2 PME. For N17 (i.e.Harbour Heights),
the predicted noise level would exceed the noise standard of 75 dB(A) by up to
5 dB(A) with Group 1 or Group 2 PME for a total of 8 weeks. For N18 (i.e. City Garden),
the predicted noise level would exceed the noise standard of 75 dB(A) by up to
9 dB(A) with Group 1 or Group 2 PME for a total of 16 weeks. For N20 (i.e. Hong Kong Baptist Church
Henrietta Secondary
School), the predicted noise level with Group 1
or Group 2 PME would exceed the noise standard of 65 dB(A) by up to 12 dB(A)
during examination periods for a total of 28 weeks in 2009, 2013 and 2015. For
the normal teaching period, the noise level would exceed the noise standard of
70 dB(A) by 7 dB(A) with Group 1 or Group 2 PME for 13.5 weeks. A summary for mitigated
noise levels during normal daytime working hours at representative NSRs is
presented in Table 4.9.
Table
4.9 Summary
of Mitigated Construction Noise Levels at Representative NSRs during Normal Daytime Working Hours
|
Representative
NSRs
|
Predicted
Mitigated Construction Noise Levels during Normal
Daytime Working Hour (Leq (30-min) dB(A))
|
|
N1
|
53 - 72
|
|
N2
|
63 - 73
|
|
N3
|
57 - 67
|
|
N6
|
57 - 69
|
|
N8
|
61 - 75
|
|
N11
|
44 - 70
(Group 1 PME)
|
|
N11
|
51 - 85
(Group 2 PME)
|
|
N13
|
55 - 71 (Group
1 PME)
|
|
N13
|
55 - 71
(Group 2 PME)
|
|
N15
|
62 - 75
|
|
N17
|
58 - 80
(Group 1 PME)
|
|
N17
|
58 - 80
(Group 2 PME)
|
|
N18
|
54 - 84 (Group 1 PME)
|
|
N18
|
54 - 84
(Group 2 PME)
|
|
N20 #
|
60 - 77
(Group 1 PME)
|
|
N20 #
|
60 - 77
(Group 2 PME)
|
|
N22
|
62 - 72
|
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.
Traffic Noise
4.8.12 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.
4.8.13 As mentioned in Sections 4.7.5
to 4.7.10, direct mitigation measures on some ‘New’ roads would be required to
mitigate the noise impact at NSRs N16, N17, N17-A, N18, N18-A, N18-B, N19, N19-A,
N20, P2 and P3. Besides, mitigation measures at NSR P1 (i.e. re-provisioned Tin Hau
Temple) would be examined
for land use planning perspective.
4.8.14 The following direct mitigation measures, as shown in Figure 4.11, have
been proposed. Taking into account the visual quality, these direct noise
mitigation measures would be installed with transparent panels:
l
about 500m length of noise
semi-enclosure covering the westbound slip road from the IEC;
l
about 230m length of
noise semi-enclosure covering the main carriageways (eastbound and westbound)
of the CWB and IEC;
l
about 135m length of 5.5m high cantilevered noise barrier with
3m cantilever inclined at
45° on the eastbound slip road to the
IEC;
l
about 95m length of 5.5m high cantilevered noise barrier with
1m cantilever inclined at
45° on the eastbound slip road to the
IEC; and
l
about 350m length of 3.5m high vertical noise barrier on the eastbound slip road to the
IEC.
4.8.15 A section of 500m length of
noise semi-enclosure covering the westbound slip road from the IEC will protect
both existing and future/planned NSRs.
Of this noise semi-enclosure, a section of the noise semi-enclosure (~265m long) located in between the
Electric Centre (next to City
Garden) and CDA(1) site
would only be required to be constructed before the occupation of
future/planned NSRs (i.e. P2 and P3). For the purpose of determining
the extent of noise semi-enclosure to be constructed before the occupation of
future/planned NSRs, the following additional noise assessment points at Oil Street as shown
in Figure 4.11 have
been included in the assessment. Considering the NSRs
alongside Electric Road
(e.g. Carson Mansion,
Swanhill Mansion,
Wah Hoi Mansion)
would be shielded by the buildings at the front row, they would not be included
in the assessment.
|
NSR
|
Section
|
Location
|
Use
|
Ground elevation (mPD)
|
No. of Floors
|
|
N24
|
Tin Hau/North Point
|
Block B, Fu Lee Loy
Mansion
|
Residential
|
4.9
|
20
|
|
N25
|
Tin Hau/North Point
|
Wan Wah Mansion
|
Residential
|
4.9
|
24
|
4.8.16 Appendix 4.15 presents the predicted road traffic noise levels at all representative
NSRs, assuming this section of noise semi-enclosure is not in place. The
results show that the predicted noise impact of ‘New’ roads on all
representative existing NSRs would comply with the criteria as stated in
Section 4.8.12 above. In order to minimise
disruption to road traffic after road opening, the steel
frame for this section of noise semi-enclosure will be erected in advance
during the construction of the westbound slip road, while the panels will be
installed before the occupation of future/planned NSRs in CDA and CDA(1) sites.
4.8.17 The remaining sections of noise semi-enclosure, cantilevered noise
barrier and vertical noise barrier shall be implemented before commencement of
operation of the proposed road project. Figure 4.11
differentiates the direct mitigation measures for existing and future/planned
NSRs. Section drawings of these direct noise mitigation measures have been
shown in Figures 4.12 to Figure 4.14.
4.8.18 As the layout and design of the re-provisioned Tin Hau Temple is not available at the time of
carrying out this EIA, a 2.5m
high boundary wall along the southern and eastern boundary of the
re-provisioned temple has been examined for its noise reduction
effectiveness. However, in view of
the traditional design of Tin
Hau Temple,
it would not be considered desirable to erect a boundary wall along the western
boundary of the temple, as this will block the seaview. With the southern and
eastern boundary wall in place but without the western boundary wall, the
predicted noise levels at the temple (i.e. NSRs P1-A and P1-B) would still
exceed EIAO-TM noise limit of 65 dB(A) by 4 dB(A) L10 (1-hour) due
to the existing roads. It should be noted that 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 65 dB(A). Instead of a
western boundary wall, the openable windows of the temple, if any, should
rather be orientated so as to avoid direct line of sight to the
existing Victoria Park Road
as far as practicable. To examine the practicality of such mitigation measure,
an indicative layout showing the orientation of sensitive façade (i.e. openable
windows of the temple) represented by NSR P1-C has been assumed for assessment
(see Figure 4.15). The results show that the predicted overall noise level at P1-C
would be 62 dB(A) L10 (1-hour) which complies with
the noise limit of 65 dB(A). The predicted noise exceedance for the
re-provisioned temple would be at the west and south facing façades only. The project proponent of the temple will need to take into account
such environmental requirements/constraints and review the mitigation measures
during the detailed design of the temple with a view to eliminating the need
for the boundary wall.
4.8.19 Appendix 4.16 presents the breakdown of noise contribution from the new roads and
existing roads at all representative NSRs when all the proposed direct
mitigation measures are in place. In view of the seaward open face of semi-enclosure and dominant
noise impact caused by vehicle traffic on open roads, tunnel portal
effect on noise would be considered
insignificant and hence has not been
included in this report.
4.8.20 With these proposed noise semi-enclosure, cantilevered and vertical
noise barriers in place, the predicted overall noise levels
at N17, N17-A, N18, N18-A, N18-B, N19, N19-A, P2 and P3 are in the range of 51
to 66 dB(A) L10 (1-hour) which comply with the noise limit of 70
dB(A).
4.8.21 For N16, the predicted overall noise levels at certain floors would
still exceed the noise limit of 70 dB(A) by 1 dB(A) 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 70 dB(A). Hence, no further
direct mitigation measures are considered effective in mitigating the noise
impact.
4.8.22 For the secondary school (NSR N20), the predicted overall noise
levels at upper floors would still exceed the noise limit of 65 dB(A) by 2 to 6
dB(A) L10 (1-hour) due to the noise contribution from existing
roads. Thus, no further direct mitigation measures would be considered
effective in mitigating the noise impact. Considering the school has already
been provided with air-conditioners, the noise impact would not be significant.
4.8.23 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. 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.
4.8.24 Nevertheless, even though the
noise level exceedence is due to noise contributions from existing roads, the overall traffic noise impact for representative NSRs
particularly in Tin Hau area and North Point area would be improved by the Project
and its associated noise barrier/noise semi-enclosure on the ‘New’ road. A comparison between the prevailing
road traffic noise level and the mitigated road traffic noise level at
representative NSRs in Tin Hau area and North Point
area is summarised below.
|
NSR ID
|
Prevailing Road Traffic
Noise Level in Year 2008, L10 (1-hr) dB(A)
|
Mitigated Road Traffic
Noise Level in Year 2031, L10 (1-hr) dB(A)
|
|
N16 – N17
|
68 – 81
|
51 - 71
|
|
N18 – N20
|
68 – 82
|
51 - 71
|
Ventilation Noise
4.8.25 As mentioned in Sections 4.7.11
to 4.7.14, there are no NSRs which will be affected by noise from the proposed East Ventilation
Building and Central Ventilation
Building. Mitigation measures are not required.
PTI Noise
4.8.26 As mentioned in Section 4.7.15,
potential noise issues are likely at Causeway Centre if no control measures are
applied. To mitigate the noise impact arising from the re-provisioned PTI,
covering of the whole bus bay areas would be recommended to be incorporated
into the design of PTI. The roof cover structure should be designed such that
the idling vehicles at the bus bay areas would be substantially screened by a
cover. With the proper design of the roof cover, no adverse PTI noise impact on
the nearby NSRs would be expected.
4.8.27 The re-provisioned PTI will be subject to the detailed design and it
will be implemented with the construction of the Exhibition Station for North
Hong Kong Island Line/Shatin to Central Link. The noise impact arising from the
PTI will be further assessed in the relevant EIA study for NIL/SCL.
Helicopter Noise
4.8.28 As mentioned in Sections 4.7.16 to 4.7.17, adverse noise impact from
the proposed permanent helipad would not be expected at the nearest NSR.
Mitigation measures are not required.
Construction Noise
4.9.1
With the exception of N11, N17, N18 and N20, the construction noise
levels at other NSRs selected for construction noise impact assessment are
predicted to comply with the noise standards stipulated in the EIAO-TM with the implementation of the above-mentioned mitigation measures.
Residual impacts at these affected NSRs are summarised in Table 4.10.
4.9.2
The on-site survey has revealed
that NSR N20 (Hong Kong
Baptist Church
Henrietta Secondary
School) has already been noise insulated with
air-conditioners. With the provision of air-conditioners, it is considered that
the noise impact would be minimised by keeping the windows closed during the
construction activities. Notwithstanding this, due to a limited buffer distance
and a more stringent noise criterion of 65 dB(A), it is recommended that particularly noisy construction
activities, especially those associated with the demolition of the IEC
Structures, should be scheduled to avoid examination
periods as far as practicable.
Table
4.10 Construction Noise
Residual Impacts
|
NSR
|
Exceedance
of the EIAO-TM Criterion of 75 dB(A)
|
Construction
Activity Causing Exceedance
|
Approximate
duration of Exceedance
|
|
N11
|
10
(Group 2 PME)
|
At-grade road
|
1 month (February 2014)
|
|
N17
|
5 (February 2013)
1 (August
2013)
4 (February 2015)
(Group 1 or Group 2 PME)
|
Demolition of structure and construction of
superstructure
|
3 weeks (February 2013)
3.5 weeks (August 2013)
1.5 weeks (February 2015)
|
|
N18
|
7 (May 2013) Land section for Group 1 or
Group 2 PME
9 (June 2013) Marine section
for Group 1 or Group 2 PME
4 (January 2014) Marine section for Group 1 or Group 2 PME
1 (February 2014) Land section for Group 1 or Group 2 PME
5 (March 2015) Land section for Group 1 PME
6 (March 2015) Land section for Group 2 PME
|
Demolition of structure and construction of
superstructure and retaining structure
|
1.5 weeks (May 2013)
2.5 weeks (June 2013)
2 weeks (January 2014)
2 weeks (February 2014)
2.5 weeks (March 2015)
2.5 weeks (April 2015)
3 weeks (November 2015)
|
|
|
7 (April 2015) Marine section for Group 1 or Group 2 PME
2 (November 2015) for Group 1 or Group 2 PME
|
|
|
|
N20 (Normal
Teaching period)
|
7 (July 2013)
3 (September 2013 – mid
November 2013)
Group 1 or Group 2 PME
|
Demolition of structure
and construction of superstructure
|
4 weeks (July 2013) ##
9.5 weeks (September 2013 – mid
November 2013) ##
|
|
N20 (Examination Period)
|
3* (May -
June 2009)
6* (May – mid-June 2013)
12* (June 2013)
10* (April 2015)
2* (May - June 2015)
(Group 1 PME)
|
Dredging, demolition
of structure and / or construction of substructure
|
8 weeks # (May - June 2009)
5.5 weeks #(May – mid-June
2013)
2.5 weeks# (June 2013)
4 weeks # (April 2015)
8 weeks # (May - June 2015)
|
|
N20 (Examination Period)
|
3* (May -
June 2009)
8* (May – mid-June 2013)
12* (June 2013)
10* (April 2015)
5* (May - June 2015)
(Group 2 PME)
|
Dredging, demolition
of structure and / or construction of substructure
|
8 weeks # (May - June 2009)
5.5 weeks #(May – mid- June
2013)
2.5 weeks# (June 2013)
4 weeks # (April 2015)
8 weeks # (May - June 2015)
|
Notes:
* Against the noise EIAO-TM noise
criterion of 65 dB(A) for examination periods.
# Public examination is
assumed to be held in March, April and May, while school examination is
assumed to be held in December and
June of each year.
## Normal teaching period is assumed to be
held in September of each year to July of the following year.
4.9.3
In
addition to the above-mentioned mitigation measures, the good site practices
listed below shall be adopted by all the Contractors to further ameliorate the
noise impacts. 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 shall be operated on-site and plant shall be serviced
regularly during the construction program.
l
Silencers
or mufflers on construction equipment shall be utilised and shall be properly
maintained during the construction program.
l
Mobile
plant, if any, shall be sited as far away from NSRs as possible.
l
Machines
and plant (such as trucks) that may be in intermittent use shall be shut down
between works periods or shall be throttled down to a minimum.
l
Plant
known to emit noise strongly in one direction shall, wherever possible, be
orientated so that the noise is directed away from the nearby NSRs.
l
Material
stockpiles and other structures shall be effectively utilised, wherever
practicable, in screening noise from on-site construction activities.
Traffic Noise
4.9.4
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 would be predicted at any of
the representative NSRs. Noise exceedances at the representative NSRs, if any,
would be due to the existing roads. The effectiveness of direct mitigation
measures, in terms of the number of residential dwellings and classrooms that
will either be protected or benefited (by at least 1 dB(A)), has been shown in Appendix 4.17.
4.9.5
In order to redress the
residual impacts, indirect technical remedies in the form of window insulation
and provision of air-conditioning should be considered subject to the
fulfilment of EPD’s eligibility criteria for consideration by the ExCo.
4.9.6
Results of the eligibility
assessment are presented in Appendix
4.18. Due to high prevailing noise levels and/or dominant noise
contribution from other roads, none of the representative NSRs is eligible for
consideration for indirect technical remedies under the EIAO-TM and the ExCo
Directive “Equitable Redress for Persons Exposed to Increased Noise Resulting
from the Use of New Roads”.
Ventilation Noise
4.9.7
No residual noise impacts are
predicted and setback distances from the ventilation buildings have been
evaluated to ensure that only non-sensitive land uses are planned in these
areas.
PTI Noise
4.9.8
No residual noise impacts are
expected at the representative NSR for the operation of proposed PTI.
Helicopter Noise
4.9.9
No residual noise impacts are
expected at the representative NSRs for the proposed permanent helipad during
normal operations.
4.10.1 As mentioned in Section 4.5.10 and
4.5.11, marine works may be undertaken over a 16-hour working day (0700 to
2300). These activities will be
under the control of the NCO and the contractors are required to apply for a
CNP from the Noise Control Authority before works commence. An indicative assessment has been
undertaken to determine the impacts.
As discussed in Section 4.2.6, the construction criterion of 65 dB(A) in
the evening was adopted in this assessment.
4.10.2 The PMEs for construction tasks during restricted hours and
assessment results are presented in Appendices
4.19 and 4.20, respectively.
On-time percentage for tug boat and crane has been reasonably assumed in this
indicative assessment. As marine-based construction activities to be carried
out during restricted hours would be confined to the area of PCWA, Wan Chai
Reclamation and HKCEC Reclamation, therefore only NSRs N1 to N3 and N6 (i.e.
within 300m of these
reclamation sites) were selected for this assessment. A summary of unmitigated
noise levels at these representative NSRs is presented in Table 4.11.
4.10.3 The lists of quiet PME adopted in the construction tasks of the
Project during restricted hours are shown in Appendix 4.21. The following construction tasks of the Project
would need to adopt quiet PME:
l
Dredging, seawalls
construction, rockfill for seawall foundations, filling behind seawall in the
areas of WCR1, WCR2, WCR3, WCR4, HKCEC1, HKCEC2 and HKCEC3 East and West.
Table
4.11 Summary of
Unmitigated Construction Noise Levels at Representative NSRs During Restricted
Hours
|
Representative
NSRs
|
Predicted
Unmitigated Construction Noise Levels during Restricted Hour (1900 to 2300 on weekday) (Leq (5-min) dB(A))
|
|
N1
|
57 – 72
|
|
N2
|
63 – 71
|
|
N3
|
62 – 64
|
|
N6
|
64 – 68
|
4.10.4 For restricted hours construction works, movable noise barriers
would be provided for mobile PME, such as excavator and poker vibrator, 5 dB(A)
noise screening reduction was assumed in the assessment. A 10 dB(A) noise screening
reduction was assumed for stationary PME such as air compressor (see Appendix 4.20).
4.10.5
Predicted noise levels after
mitigation at representative NSRs are shown in Appendix 4.22.
A summary of mitigated noise levels at representative NSRs is presented in Table 4.12.
Table
4.12 Summary of
Mitigated Construction Noise Levels at Representative NSRs During Restricted
Hours
|
Representative
NSRs
|
Predicted
Mitigated Construction Noise Levels during Restricted Hour (1900 to 2300 on weekday) (Leq (5-min) dB(A))
|
|
N1
|
53 – 63
|
|
N2
|
55 – 67
|
|
N3
|
57 – 62
|
|
N6
|
60 – 65
|
4.10.6 With the adoption of the recommended mitigation measures, the
predicted noise levels at NSRs N1 (HKAPA Open Arena), N3 (Gloucester Road 169-170) and N6 (Elizabeth
House) would comply with the construction noise criterion of 65 dB(A) during
restricted hours. For N2 (Causeway Centre), there would be 2 dB(A) exceedance
of noise limit due to dredging works based on the current information. The
Applicant (i.e. the Contractor) shall implement all practicable noise
mitigation measures to mitigate the noise impact. In applying for a
Construction Noise Permit, the Contractor shall be required to demonstrate to
the satisfaction of the Noise Control Authority the Sound Power Level of the
quiet PMEs and/or the noise reduction effect of other mitigation measures to be
adopted. Otherwise, values in the
GW-TM will be used in assessing the application.
4.10.7 The above assessment only demonstrates that the construction works in
restricted hours would be feasible in the context of programming construction
work. If the Contractor considers that there is a need to carry out
construction works during restricted hours, a Construction Noise Permit shall
be obtained from the Noise Control Authority prior to commencement of such
works. There are some factors
affecting the assessment results of a CNP application, such as the assigning of
Area Sensitivity Rating, Acceptable Noise Levels etc. The Noise Control Authority would decide
these at the time of assessment of such application based on the contemporary
situations / conditions. It should
be noted that the situations / conditions around the sites may change from time
to time. The Authority may make
correction for multiple permit situations if in the opinion of the Authority
the NSR will be materially affected by noise from construction work associated
with more than one CNP, and the Authority may make such correction to the
relevant noise level as it considers appropriate having regard to standard
acoustical principles and practices. The Area Sensitivity Ratings assumed in
this EIA Report are for indicative assessment only.
Construction Noise
4.11.1
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.
Operational Noise
4.11.2
No residual impacts from PTI
noise and helicopter noise are expected at the NSRs. Therefore, no monitoring
is required during operation of the PTI and helipad.
4.11.3
The assessment has indicated
that the noise from ventilation buildings would comply with the EIAO-TM
standards. As part of the design process, however, monitoring of operation
noise from proposed EVB during the testing and commissioning stage would be
recommended to verify the maximum sound power levels as assumed in the noise
assessment in this EIA.
4.11.4
Road traffic noise levels
should be monitored at representative NSRs, which are in the vicinity of the
recommended direct mitigation measures, during the first year after road
opening. Details of the programme are provided in the
stand-alone EM&A Manual.
Construction
Phase
4.12.1
This
assessment has predicted the construction noise impacts of the Project during
normal daytime working hours, taking into account other concurrent projects
including the CRIII and HKCEC ALE projects. The predicted unmitigated noise
levels would range from 57 to
101 dB(A) at the representative NSRs. With the use of quiet PME, movable barriers, temporary barriers and PME
grouping for construction tasks under the Project and implementation of the
noise mitigation measures proposed in the CRIII Reports, the noise levels at the NSRs selected for
construction noise impact assessment except N11, N17, N18 and N20 would comply with the construction noise
standard.
4.12.2
Having exhausted practicable
noise mitigation measures, the predicted noise level at N11 (i.e Mayson Garden)
would exceed the noise standard of 75 dB(A) for 1 month by 10 dB(A)
with Group 2 PME. For N17 (i.e.Harbour Heights),
the predicted noise level would exceed the noise standard of 75 dB(A) by up to
5 dB(A) with Group 1 or Group 2 PME for a total of 8 weeks. For N18 (i.e. City Garden),
the predicted noise level would exceed the noise standard of 75 dB(A) by up to
9 dB(A) with Group 1 or Group 2 PME for a total of 16 weeks. For N20 (i.e. Hong
Kong Baptist Church Henrietta Secondary School), the predicted noise level with
Group 1 or Group 2 PME would exceed the noise standard of 65 dB(A) by up to 12
dB(A) for Group 1 or Group 2 PME during examination periods for a total of 28
weeks in 2009, 2013 and 2015. For the normal teaching period, the noise level
would exceed the noise standard of 70 dB(A) by 7 dB(A) with Group 1 or Group 2
PME for 13.5 weeks. However, the school has been noise insulated with air conditioners
and, by keeping the windows closed during construction activities, noise
impacts at the indoor environment can be avoided. Notwithstanding this, it is recommended that
the particularly noisy construction activities be scheduled to avoid examination
period as far as practicable.
4.12.3
Whilst this impact assessment does indicate some
noise exceedances for limited periods of time, even with the consideration of
all practicable mitigation measures, during the actual construction period as
much as practically possible will be done to reduce construction noise still
further, and there will be on-going liaison with all concerned parties and site
monitoring to deal with and minimise any exceedances.
4.12.4
The proposed cross harbour
water mains will extend from Wan Chai near the HKCEC Extension to connect to
the existing system near the Museum
of Arts at the Tsim Sha
Tsui promenade. Insignificant
construction noise impacts are expected on the indoor environment of the NSRs
such as the HKCEC Extension, the Hong Kong Space Museum and the Museum of Arts,
which are close to the construction sites at Wan Chai and Tsim Sha Tsui, as
they have blank façades / fixed windows and are provided with central air
conditioning, and therefore do not rely on openable windows for ventilation.
4.12.5
An
indicative assessment has been undertaken for possible construction activities
during restricted hours (1900 to 2300) associated with the reclamation works of
the Project. With the adoption of quite PME and movable noise barriers, the
predicted noise levels at the NSRs selected for noise impact assessment except
NSR N2 would comply with construction noise
criterion of 65 dB(A). It should be noted that the results of the construction
noise impact assessment for restricted hours (1900 to 2300) are for indicative
purposes, the Noise Control Authority will process any CNP application based on
the NCO and the relevant technical memoranda in addition to considering the
contemporary situations / conditions.
4.12.6
A
construction noise EM&A programme is recommended to check the compliance of
the noise criteria during normal daytime working hours.
Operational Phase
4.12.7
The potential road traffic
noise impacts have been assessed based on the worst case traffic flows in 2031.
The noise levels at most of the NSRs in the areas of Wanchai, Causeway Bay,
Tin Hau and North Point are predicted to exceed the EIAO-TM traffic noise
criteria due to the existing roads. Without the noise mitigation measures in
place, the predicted noise levels at the NSRs would range from 60 to 87 dB(A).
As a result, direct mitigation measures have been proposed to mitigate the
noise impacts at NSRs N16, N17, N17-A, N18, N18-A, N18-B, N19, N19-A, N20, P2
and P3 where ‘New’ road noise levels would exceed the relevant noise criteria
and ‘New’ road noise contributions to the overall noise levels would be more
than 1.0 dB(A).
4.12.8
With the proposed noise
semi-enclosure, cantilevered noise barrier and vertical noise barrier in place,
the predicted overall noise levels at N17, N17-A, N18, N18-A, N18-B, N19, N19-A,
P2 and P3 would be in the range of 51 to 66 dB(A) which comply with the noise
limit of 70 dB(A). For all other affected NSRs, the ‘New’ road noise
contributions to the overall noise levels would be less than 1.0 dB(A) and the
‘New’ road noise levels would all be below the relevant noise criteria,
although the overall noise levels 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.
Nevertheless, there will be an overall reduction of noise brought about
by the project, which may be considered an environmental benefit.
4.12.9
A section of the noise
semi-enclosure (~265m long)
located in between the Electric Centre and CDA(1) site would only be required to
be constructed before the occupation of future/planned NSRs (P2 – A land zoned as “CDA(1)” near
Oil Street and P3 – A land zoned as CDA near Oil Street), while the remaining sections of noise semi-enclosure and vertical
noise barrier shall be implemented before commencement of operation of the
proposed road project.
4.12.10
For noise mitigation at the
proposed site of the reprovisioned floating Tin
Hau Temple,
at the south-east corner of the CBTS, a 2.5m high boundary wall along the southern and eastern
boundary of re-provisioned Tin
Hau Temple
has been examined for its noise reduction effectiveness. However, in view of the
traditional design of a Tin
Hau Temple,
it would not be considered desirable to erect a boundary wall along the western
boundary of the temple, as this will block the seaview. With the southern and
eastern boundary wall in place but without the western boundary wall,
the predicted noise levels at the temple would still exceed EIAO-TM noise limit
of 65 dB(A) by 4 dB(A) due to the existing roads. Instead of a western boundary
wall, the openable windows of the temple should rather be orientated so as to
avoid direct line of sight to the existing Victoria Park Road as far as
practicable. An indicative layout
for the temple has demonstrated that the traffic noise criterion would be met
with proper orientation of the sensitive façade. The project proponent of
the temple will need to take into account such environmental
requirements/constraints and review the mitigation measures during the detailed
design of the temple with a view to eliminating the need for the boundary wall.
4.12.11
No adverse impacts in respect
of the NCO and the EIAO-TM noise criteria arising from the operation of the
proposed permanent helipad and fixed noise sources including ventilation buildings
and the reprovisioned Wan Chai North PTI are anticipated at existing and
planned NSRs.
4.12.12
Monitoring of road traffic
noise is recommended to verify the effectiveness of the mitigation schemes during
the first year after road opening. Besides, as part of the design process, monitoring of
operation noise from proposed EVB during the testing and commissioning stage
would be recommended to verify the maximum sound power levels as assumed in the
noise assessment in this EIA.