4 NOISE.. 4-1
4.1 Introduction. 4-1
4.2 Environmental Legislation, Policies, Plans,
Standards and Criteria. 4-1
4.3 Description of the Environment 4-2
4.4 Sensitive Receivers. 4-2
4.5 Assessment Methodology. 4-2
4.6 Identification of Environmental Impacts. 4-2
4.7 Prediction and Evaluation of Environmental Impacts. 4-2
4.8 Mitigation of Adverse Environmental Impacts. 4-2
4.9 Evaluation of Residual Impacts. 4-2
4.10 Environmental Monitoring and Audit 4-2
4.11 Conclusion. 4-2
4
NOISE
4.1.1
This
section presents the potential noise impacts arising from the construction and
operation of Central-Wanchai Bypass (CWB) including its road tunnel and slip
roads. It is expected that construction noise impact will arise from the
proposed Project as well as the nearby concurrent projects (i.e. other Schedule
2 Designated Projects, 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. SCL and NIL) were not available, therefore
the cumulative noise impact arising from these two railway projects has not
been assessed in this section. Construction work of CWB has been scheduled to
be carried out during unrestricted hours, therefore an indicative construction
noise assessment for restricted hours was not 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
Project boundary (the Study Area).
Assessments for ventilation noise from the proposed East and West Ventilation
Buildings have been
undertaken to evaluate the impacts on the nearby sensitive receivers.
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:
·
EIAO-TM
·
TM
on Noise from Construction Work other than Percussive Piling (GW-TM)
·
TM
on Noise from Percussive Piling (PP-TM)
·
TM
on Noise from Construction Work in Designated Areas (DA-TM)
·
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
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.
4.2.7
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
|
|
|
|
|
|
|
4.2.8
Under
the TM on Noise from Construction Work in Designated Areas, the use of five
types of Specified Powered Mechanical Equipment (SPME) and three types of
Prescribed Construction Work (PCW) within a designated area during restricted
hours would require a valid CNP.
The SPME includes hand-held breaker, bulldozer, concrete lorry mixer,
dump truck and hand-held vibratory poker.
The PCW are:
·
erecting
or dismantling of formwork or scaffolding
·
loading,
unloading or handling of rubble, wooden boards, steel bars, wood or scaffolding
material
·
hammering
4.2.9
In
general, it should not be presumed that a CNP would be granted for carrying out
PCW within a designated area during 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.
4.2.10
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
·
70
dB(A) at the façades of dwellings, hotels, offices
·
65
dB(A) at the façades of schools, places of public worship, courts of law,
places where unaided voice communication is required
·
55
dB(A) at the façades of hospital
4.2.12
If
any façades of NSRs are still exposed to predicted noise levels exceeding the
relevant noise criteria after the implementation of all direct mitigation
measures, provision of indirect technical remedies in the form of acoustic
insulation and air conditioning should be considered under the EIAO-TM and the
ExCo Directive “Equitable Redress for Persons Exposed to Increased Noise
Resulting from the Use of New Roads”.
The eligibility for indirect technical remedies will be tested against
the following three criteria:
·
the
predicted overall noise level from the new road, together with other traffic
noise in the vicinity must be above a specified noise level (for example, 70
dB(A) for domestic premises and 65 dB(A) for educational institutions, all in L10
(1 hour)); and
·
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
·
the
contribution to the increase in the predicted overall noise level from the new
road must be at least 1.0 dB(A).
4.2.13
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:
·
‘Existing’
Roads are the roads that are unchanged or subject to minor changes by the
Project.
·
‘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).
4.2.14
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).
4.2.15
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)
4.2.16
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)
4.2.17
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)
4.2.18
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)
4.2.19
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.
4.2.20
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)
4.2.21
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.
4.2.22
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
|
4.2.23
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.
4.3
Description of the Environment
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 the Project will overlap with other Schedule 2 DPs,
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 and ventilation 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
|
Gorden 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
(EVB) with a buffer distance of about 115m and 250m,
respectively. Existing receivers in the vicinity of the Central Ventilation
Building (CVB) 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 ventilation noise assessment of EVB.
For the purpose of land use planning, the minimum buffer distances between the
NSR and the proposed EVB and CVB would also be identified.
Construction
Noise
4.5.1
The
Schedule 3 Designated 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 reclamation 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:
CRIII Project
·
CWB
under CRIII main contract (December 2008 – March 2012)
·
Drainage
Culverts (October 2008 – September 2012)
·
Roadworks
(October 2008 – September 2012)
HKCEC ALE Project
·
Remove
marine piles for working platform (October 2008 – November 2008)
·
Demolish
temporary footbridge (December 2008 – February 2009)
·
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.
Operational
Phase – Road Traffic Noise
4.5.11
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.
4.5.12
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
4.5.13
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.
4.5.14
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.
4.5.15
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.
4.5.16
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.
4.5.17
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)
|
4.5.18
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.
Level of
Uncertainty
4.5.19
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.
4.5.20
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.
4.5.21
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.
4.5.22
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.
Construction Phase
4.6.1
Schedule
2 DP1 is scheduled to be commenced in early 2009 and to be completed in 2016.
The construction tasks under DP1 include:
·
construction of CWB including
its road tunnel and slip roads
·
construction of CVB and EVB and
administration building;
·
construction of IECL
·
construction of tunnel portal
4.6.2
The
construction tasks of this DP1 and other projects taking place concurrently
within 300m 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. The
concurrent projects considered in the cumulative construction noise assessment
for DP1 are as follows:
·
DP2 - Road P2 and other roads
which are classified as primary/distributor roads
·
DP3 - reclamation works
including associated dredging works
·
DP4 - temporary typhoon shelter
·
DP5 - Wan Chai East Sewage
Outfall
·
DP6 - dredging for the
cross-harbour water mains from Wan Chai to Tsim Sha Tsui
·
Central Reclamation Phase III
(CRIII)
·
Hong Kong Convention and Exhibition Centre, Atrium Link Extension (HKCEC ALE)
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:
Ÿ
road
traffic noise
Ÿ
ventilation
noise
4.6.6
Road
traffic noise will arise from new roads constructed under the Project as well
as the new roads under DP2 and 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).
Construction
Noise
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, other Schedule 2 DPs, CRIII and HKCEC ALE projects are in the range of
57 to 101 dB(A). 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
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.
4.7.3
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)
4.7.4
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)
4.7.5
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)
4.7.6
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.
4.7.7
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 )
4.7.8
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.
4.7.9
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
4.7.10
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.
4.7.11
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
4.7.12
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.
4.7.13
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.
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:
·
Diaphragm
wall, excavation, construction of slabs and backfilling in CWB tunnel construction
·
Rock
excavation at CWB tunnel (Cross Harbour Tunnel section)
·
Slip
Road 8 and Victoria Park Road
reprovisioning and at-grade road construction
·
Substructure
and superstructure for landscaped deck, connection of IECL
·
Demolition
of structure, including the IEC structure
·
Road
works construction
·
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 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),
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 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 4.7.4 to 4.7.9, 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.
·
about 500m length of noise
semi-enclosure covering the westbound slip road from the IEC;
·
about 230m length of noise
semi-enclosure covering the main carriageways (eastbound and westbound) of the
CWB and IEC;
·
about
135m length of 5.5m high cantilevered noise barrier with 3m cantilever inclined at 45° on the eastbound slip road to the IEC;
·
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
·
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-enclousue to be constructed before the occupation of
future/palnned 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 drawing of
these direct noise mitigation measures have been shown in Figures 4.12 to 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 and boundary wall 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 4.7.10 to 4.7.13, 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.
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 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 70 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
|
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)
|
|
|
5 (March 2015) Land section for
Group 1 PME
6 (March 2015) Land section for
Group 2 PME
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.
Ÿ
Only well-maintained plant shall be operated on-site and
plant shall be serviced regularly during the construction program.
Ÿ
Silencers or mufflers on construction equipment shall be
utilised and shall be properly maintained during the construction program.
Ÿ
Mobile plant, if any, shall be sited as far away from
NSRs as possible.
Ÿ
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.
Ÿ
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.
Ÿ
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.
Construction Noise
4.10.1
An
EM&A programme is recommended to be established according to the predicted
occurrence of noisy activities. All the recommended mitigation measures for
daytime normal working activities should be incorporated into the EM&A
programme for implementation during construction. Details of the programme are provided in
the stand-alone EM&A Manual.
Operational Noise
4.10.2
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.
4.10.3
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.
Construction Phase
4.11.1 This
assessment has predicted the construction noise impacts of the Project during
normal daytime working hours, taking into account other concurrent Schedule 2
DPs, 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.
4.11.2 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.
4.11.3 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..
4.11.4 A
construction noise EM&A programme is recommended to check the compliance of
the noise criteria during normal daytime working hours.
Operational Phase
4.11.5
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).
4.11.6
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.
4.11.7
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 (i.e. P2 and P3), while the remaining
sections of noise semi-enclosure and vertical noise barrier shall be
implemented before commencement of operation of the proposed road project.
4.11.8
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.
4.11.9
N adverse impacts in respect of the NCO and the
EIAO-TM noise criteria arising from the operation of the proposed ventilation
buildings are anticipated at existing and planned NSRs.
4.11.10
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.