4.1
Introduction
4.1.1
This section presents the
potential noise impacts arising from the proposed Project during construction
and operational phases. It is expected
that the construction noise impact will be attributed to the proposed Project
as well as other concurrent projects such as the CRIII and the CWB & IECL
projects. Cumulative daytime
construction noise impacts are assessed in this study. An indicative assessment for construction
works undertaken within restricted hours is also undertaken.
4.1.2
During the operational phase,
traffic noise impacts would be expected and traffic noise assessment is
therefore undertaken at the representative noise sensitive receivers within 300
m from the boundary of the development area (the Study Area). Assessment for helicopter noise from the
proposed helipads has been undertaken to evaluate the impacts on the nearby
sensitive receivers. For land use
planning purpose, quantitative assessment for ventilation noise sources has
been undertaken, however, since most of the proposed new developments in the
Project are commercial buildings, hotels and museums, which are provided with
central air conditioning and do not rely on openable windows for air
ventilation, no adverse noise impacts are expected from the proposed CWB ventilation
buildings. The seawater pumping stations
will also be fixed noise sources but they are located underground and buffered
from potential receivers by open areas.
No significant fixed noise impacts from pumping stations are anticipated
and, therefore, no assessment has been carried out on the proposed new
developments.
General
4.2.1
Noise impacts will be assessed
in accordance with the criteria and methodology given in the Technical
Memoranda (TMs) under the Noise Control Ordinance (NCO), and the Technical
Memorandum on Environmental Impact Assessment Process (EIAO-TM).
4.2.2
The NCO and EIAO provide the
statutory framework for noise control.
Assessment procedures and standards 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
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 1A 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)
|
|
|
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 of 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 and law or other
NSRs which are considered by the Authority to be
particularly sensitive to noise.
4.2.8
Effective from 1 October 1999,
diesel, pneumatic and / or steam hammers are not allowed to be used in Hong
Kong. The permitted hours of operation
for carrying out of percussive piling work, subject to the issuance of a CNP,
are listed in Table 4.3.
Table 4.3 Permitted Hours of Operation for
Percussive Piling
|
Amount by which Corrected Noise Level (CNL)
exceeds Acceptable Noise Level (ANL), CNL-ANL
|
|
|
|
|
|
0 dB(A) <
CNL-ANL £ 10 dB(A)
|
0800 to 0930
AND 1200 to 1400 AND 1630 to 1800
|
|
CNL- ANL £ 0 dB(A)
|
0700 to 1900
|
4.2.9
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:
·
erecting or dismantling of
formwork or scaffolding;
·
loading, unloading or handling
of rubble, wooden boards, steel bars, wood or scaffolding material;
·
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.
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, place where unaided voice
communication is required; and
·
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 were commenced; and
·
the contribution to the
increase in the predicted overall noise level from the new road must be at
least 1.0 dB(A).
4.2.13
For the purpose of the traffic
noise assessment in this Report, the roads within the 300 m from the boundary
of the reclamation area 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 and the proposed
roads from CRIII Project.
·
‘New’ Roads are the roads that
are completely new or existing road sections that undergo major modifications
that will result in a 25% increase in lanes or substantial change in alignment
or character of the existing road due to the WDII Project.
·
‘New (Others)’ Roads are the
roads that are completely new or existing road sections that undergo major
modifications that will result in a 25% increase in lanes or substantial change
in alignment or character of the existing road due to other projects such as
the CWB & IECL project.
4.2.14
The ‘New’ roads adopted for the
WDII Project in the assessment are shown in Figures A4.1 and A4.2 in Appendix
4.1.
4.2.15
Fixed noise source such as
ventilation shaft 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 with an average daily traffic flow in excess
of 30,000 and the low traffic flow rate would be more than 300 vehicles per
hour. 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 are facing north and Gloucester Road is 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) will
be adopted for assessment.
Table 4.4 Acceptable Noise Level for Fixed Plant
Noise
|
Time Period
|
NCO criteria
|
EIAO-TM
|
|
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
|
4.2.16 In any event, the Area Sensitivity Rating assumed in this EIA Report
is for indicative assessment only given that fans and damper arrangement at
each ventilation building may be refined in detailed design. 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
4.2.17
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, education institutes, hospitals and places of
worship during 0700 to 1900 hours. The
standards apply to uses that rely on openable windows
for ventilation.
4.3.1
The existing land uses in Wan Chai and Causeway Bay near the proposed development are
commercial, residential and recreational uses.
The dominant existing noise source comes from the road traffic on busy
Gloucester Road, Harcourt Road, Victoria Park Road and Island Eastern Corridor.
4.3.2
Construction work for the
extension of Wan Chai East Sewage Screening Plant is
currently in progress. The screening
plant is located at Wan Shing Street near the Wan Chai Public Cargo Working Area (PCWA). It is unlikely that exceedences
of the stipulated limit levels for construction will be recorded during the
environmental monitoring programme.
Besides, the construction work of this project is nearly complete.
4.3.3
Since the works programme of
WDII project will overlap with the CRIII project and the CWB & IECL project
in some periods, cumulative construction noise impacts would be expected at
some noise sensitive receivers.
4.4.1
In accordance with Annex 13 of
the EIAO-TM, the existing noise sensitive receivers (NSRs)
within the Study Area have been identified and are summarised in Table 4.5.
Table 4.5 Summary of Identified Existing Noise
Sensitive Receivers
|
Area
|
Location
|
Use
|
|
Central
|
PLA Headquarters
|
Others (Military)
|
|
Wan Chai
|
HKAPA
|
Educational Institution
|
|
|
HKAPA (Open Arena)
|
Performing Arts Centre
|
|
|
Art Centre
|
Performing Arts Centre
|
|
|
Hong Kong Convention & Exhibition Centre (HKCEC) Extension
|
Convention and Exhibition
|
|
|
Causeway Centre
|
Residential
|
|
|
City Mansion
|
Residential
|
|
|
170 Gloucester Road
|
Residential
|
|
|
Kam Kwok Building, 210 Gloucester Road
|
Residential
|
|
|
Kei Wa
Building
|
Residential
|
|
|
Hyde Centre
|
Residential
|
|
|
Sang Woo Building
|
Residential
|
|
Causeway Bay
|
Elizabeth House
|
Residential
|
|
|
Hoi Kung Court
|
Residential
|
|
|
Hoi To Court
|
Residential
|
|
|
Hoi Deen
Court
|
Residential
|
|
|
Riviera Mansion
|
Residential
|
|
|
Prospect Mansion
|
Residential
|
|
|
Miami Mansion
|
Residential
|
|
|
Highland Mansion
|
Residential
|
|
|
Marco Polo Mansion
|
Residential
|
|
|
Victoria Park Mansion
|
Residential
|
|
|
Chesterfield Mansion
|
Residential
|
|
|
Greenfield Mansion
|
Residential
|
|
Tin Hau
|
Viking Garden
|
Residential
|
|
|
Victoria Court
|
Residential
|
|
|
Mayson Garden
|
Residential
|
|
|
Gorden House
|
Residential
|
|
|
Belle House
|
Residential
|
|
|
Hoi Tao Building
|
Residential
|
|
|
Depot of Food and
Environmental Hygiene Department
|
Government quarters and
office
|
|
|
Victoria Centre
|
Residential
|
|
|
Harbour Heights Tower
|
Residential
|
4.4.2
In order to evaluate the
construction and operational noise impacts from the Project alignments,
representative existing and planned noise sensitive receivers (NSRs) within the Study Area are identified for
assessment. Table 4.6 summarises the
representative NSRs for construction noise assessment
while Table 4.7 summarises the representative NSRs
for traffic noise impact assessment. The
locations of the representative NSRs are shown in
Figure 4.1.
Table 4.6 Summary of Representative Existing
Noise Sensitive Receivers for Construction Noise Impact Assessment
|
NSR
|
Section
|
Location
|
Use
|
Ground elevation (mPD)
|
No. of Floors
|
|
N1
|
Wanchai
|
HKAPA (Open Arena)
|
Performing Arts Centre
|
5.0
|
G/f
|
|
N2
|
Wanchai
|
Art Centre
|
Performing Arts Centre
|
4.0
|
10
|
|
N3
|
Wanchai
|
HKCEC Extension
|
Convention and Exhibition
|
5.5
|
8
|
|
N4
|
Wanchai
|
Causeway Bay Centre
|
Residential
|
4.0
|
42
|
|
N5
|
Wanchai
|
Gloucester Road 169-170
|
Residential
|
3.7
|
12
|
|
N8
|
Causeway Bay
|
Elizabeth House
|
Residential
|
3.7
|
21
|
|
N9
|
Causeway Bay
|
Riviera Mansion
|
Residential
|
4.3
|
15
|
|
N11
|
Causeway Bay
|
Marco Polo Mansion (eastern façade)
|
Residential
|
4.3
|
15
|
|
N14
|
Tin Hau
|
Mayson Garden
|
Residential
|
4.0
|
24
|
|
N16
|
Tin Hau
|
Belle House
|
Residential
|
3.6
|
24
|
|
N18
|
Tin Hau
|
Victoria Centre
|
Residential
|
4.0
|
30
|
Table 4.7 Summary of Representative Existing and
Planned Noise Sensitive Receivers for Traffic Noise Assessment
|
NSR
|
Section
|
Location
|
Use
|
Ground elevation (mPD)
|
No. of Floors
|
|
N1
|
Wanchai
|
HKAPA (Open Arena)
|
Performing Arts Centre
|
5.0
|
G/F
|
|
N2
|
Wanchai
|
Art Centre
|
Performing Arts Centre
|
4.0
|
10
|
|
N3
|
Wanchai
|
HKCEC Extension
|
Convention and Exhibition
|
5.5
|
8
|
|
N4
|
Wanchai
|
Causeway Bay Centre
|
Residential
|
4.0
|
42
|
|
N5
|
Wanchai
|
Gloucester Road 169-170
|
Residential
|
3.7
|
12
|
|
N6
|
Wanchai
|
Kam Kwok
Building
|
Residential
|
3.7
|
18
|
|
N7
|
Wanchai
|
Hyde Centre
|
Residential
|
3.7
|
22
|
|
N8
|
Causeway Bay
|
Elizabeth House
|
Residential
|
3.7
|
21
|
|
N9
|
Causeway Bay
|
Riviera Mansion
|
Residential
|
4.3
|
15
|
|
N10
|
Causeway Bay
|
Marco Polo Mansion (northern façade)
|
Residential
|
4.3
|
15
|
|
N11
|
Causeway Bay
|
Marco Polo Mansion (eastern façade)
|
Residential
|
4.3
|
15
|
|
N12
|
Tin Hau
|
Viking Garden
|
Residential
|
4.0
|
25
|
|
N13
|
Tin Hau
|
Victoria Court
|
Residential
|
4.0
|
18
|
|
N14
|
Tin Hau
|
Mayson Garden
|
Residential
|
4.0
|
24
|
|
N15
|
Tin Hau
|
Gorden House
|
Residential
|
4.0
|
15
|
|
N16
|
Tin Hau
|
Belle House
|
Residential
|
3.6
|
24
|
|
N17
|
Tin Hau
|
Hoi Tao Building
|
Residential
|
4.0
|
30
|
|
N18
|
Tin Hau
|
Victoria Centre
|
Residential
|
4.0
|
30
|
|
N19
|
Tin Hau
|
Harbour Heights
|
Residential
|
4.3
|
44
|
|
N20
|
Wanchai
|
Proposed Tin Hau Temple Site
|
Temple
|
-
|
G/F
|
4.4.3
According to the latest land
use planning for WDII, the land uses of most future developments are
commercial, hotels, recreational facilities, museum, temple and open
spaces. Commercial buildings, museums
and recreational facilities are not defined as NSRs
in accordance with Annex 13 of the EIAO-TM.
Hotels and museums 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.
Only one future NSR, a temple that is located near Hing
Fat Street, is identified.
4.4.4
There are no existing noise
sensitive receivers in the vicinity of the proposed western and eastern CWB
ventilation buildings. Receivers in the
vicinity of the central ventilation building such as the Hong Kong Academy for
Performing Arts (HKAPA) and the Art 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. Based on the current land use planning in
WDII, no new noise sensitive receivers will be located around the proposed
ventilation buildings. The fixed noise
assessment for ventilation shaft noise is to evaluate the area that would be
affected for the purpose of land use planning, therefore, no representative NSRs are selected.
4.4.5
To evaluate the noise from the
proposed helipads, HKCEC Extension and Causeway Bay Centre which are closest to
the permanent helipad location, and Elizabeth House which is closest to
temporary helipad location, are identified as representative NSRs for helicopter noise assessment.
Construction Noise During Unrestricted Hours
4.5.1
The Project is scheduled to be
commenced in March 2004 and to be completed in February 2010. According to the construction programme of
WDII, there are nine major construction tasks (as shown in Appendix 2.1). Some individual tasks have different
stages. Table 4.8 summarises the
different tasks and phasing. Figure 3.2
shows the locations of different construction site. All construction tasks are carried out during
unrestricted hours (0700 to 1900 hours Monday to Saturday excluding general
holidays).
Table 4.8 Summary of Construction Tasks and
Stages for WDII
|
Item
|
Tasks and Stages
|
Construction Period
|
Main Construction
Elements
|
|
1
|
Causeway Bay Reclamation
|
|
|
|
1.1
|
Causeway Bay Reclamation Stage 1
|
March 2004 to November 2006
|
Dredging, seawalls and filling
Cooling water intake chambers
Connect cooling water intake and outfall pipelines
New diversion culvert and connect culvert outfall
Culvert’s Outfall
|
|
1.2
|
Causeway Bay Reclamation Stage 2
|
March 2006 to December 2007
|
Dredging, seawalls and filling
Extend new diversion culvert and connect Culvert Q outfall
Culvert P outfall
|
|
1.3
|
Typhoon Shelter
|
March 2006 to April 2006
|
Removal of end of existing breakwater
|
|
2
|
Wan Chai Reclamation
|
|
|
|
2.1
|
Wan Chai Reclamation
Stage 1
|
March 2004 to March 2006
|
Dredging, seawalls and filling
Cooling water intake chambers
Diaphragm wall for CWB tunnel
CWB tunnel box and backfill
Connect cooling water intake and outfall pipelines
Culverts N outfall
|
|
2.2
|
Wan Chai Reclamation
Stage 2
|
November 2005 to October 2008
|
Dredging, seawalls and filling
Demolish HKCEC East bridge
Culvert M outfall
Diaphragm wall for CWB tunnel
CWB tunnel box and backfill
|
|
2.3
|
Wan Chai Reclamation
Stage 3
|
June 2004 to December 2008
|
Dredging, seawalls and filling
Culvert O outfall
Diaphragm wall for CWB Tunnel
CWB tunnel box and backfill
|
|
2.4
|
PCWA Basin
|
April 2004 to February 2005
|
Dredging, seawalls and filling
|
|
3
|
HKCEC Reclamation
|
|
|
|
3.1
|
HKCEC Reclamation Stage 1 (Water Channel)
|
March 2004 to August 2006
|
Cooling water intake and outfall pipelines
Seawalls and filling
Diaphragm wall for CWB tunnel
CWB tunnel box and backfill
|
|
3.2
|
HKCEC Reclamation Stage 2
|
August 2004 to November 2008
|
Divert services and road access
Demolish HKCEC West Bridge
Dredging, seawalls and filling
Diaphragm walls for CWB tunnel
CWB tunnel box and backfill
Culvert L outfall
|
|
3.3
|
Mass Transit Railway Tunnel Crossing
|
July 2005 to February 2006
|
Piling for CWB tunnel unit and deck
Place CWB tunnel unit and deck construction
|
|
4
|
Ferry Pier Reprovisioning
|
|
|
|
4.1
|
Temporary Ferry Piers
|
March 2004 to October 2004
|
Relocation to temporary piers
Demolish existing pier structures
|
|
4.2
|
New Ferry Piers
|
January 2006 to March 2007
|
Piling and deck construction
Relocation to new piers
|
|
5
|
Marina
|
June 2004 to January 2006
|
Dredging, seawalls and filling for breakwater
|
|
6
|
Helipad
|
March 2007 to January 2008
|
Piling and deck construction
Reprovisioning
at HKCEC
|
|
7
|
Wan Chai East Sewage Plant and Outfall
|
November 2004 to April 2006
|
Sewage outfall reprovisioning
|
|
8
|
Cross Harbour Watermains
|
March 2004 to July 2005
|
Lay new submarine and landside pipelines
|
|
9
|
Roads and Landscaping
|
May 2007 to February 2010
|
Road P2
Demolish existing Hung Hing Road flyover
and construction of new flyover
Road P2 flyover and local access roads
Promenade
|
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 quarterly basis from the commencement of
the Project. The construction tasks of
the Project taking place concurrently within 500 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. The minimum distances from the notional
source points of each construction activity to the representative NSRs are given in Appendix 4.3.
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 will be taken from Table 3 of this TM. Where no SWL was supplied in the GW-TM,
reference will be made to BS 5228, previous similar studies or from
measurements taken at other sites in Hong Kong.
4.5.5
It is assumed that all PME
items required for a particular construction activity are located at the
notional or probable source position of the segment where such activity is
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,
their frequency of operation and their distance from receivers. The noise levels at NSRs
were then predicted by adding up the SWLs of all
concurrent construction tasks.
4.5.6
A positive 3 dB(A) façade
correction was added to the predicted noise levels in order to account for the
facade 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.
4.5.7
The CRIII project will commence
in August 2002 and will be completed in March 2007. The CWB & IECL project will commence in
March 2004 and is expected to be completed in February 2012. Therefore, some construction tasks of the
CRIII and CWB & IECL projects will be carried out within the same
construction period of WDII (March 2004 to February 2010). The following construction activities of
these projects will overlap with the WDII Project:
CWB & IECL Project
(IECL section)
·
IECL bridge foundations (March
2008 – November 2009);
·
IECL bridge deck construction
activities (June 2008 – August 2011);
·
CWB East Ventilation Building
and Administration Building – superstructure construction;
·
At-grade roads.
CWB & IECL Project
(Exhibition section)
·
CWB Central Ventilation
Building – superstructure construction;
CRIII Project
·
Stage 3 to Stage 8 (March 2004
– March 2007) construction works in accordance with the EIA Report of CRIII().
4.5.8
According to the latest
programme provided by Highways Department, the construction of Causeway Bay
Flyover, which is a separate project from WDII, is scheduled to commence in May
2003 for completion in February 2006.
The construction period will overlap with the WDII project. Therefore, the impact arising from the
construction of Causeway Bay Flyover has also been considered in the
assessment. For indicative assessment
purposes, the same PMEs for Hung Hing
Road Flyover have been adopted for the Causeway Bay Flyover.
4.5.9
The PMEs
for the above construction activities are in accordance with the EIA Report of
the CWB & IECL() and EIA Report of CRIII, and their
respective results are adopted for assessment in this study.
4.5.10
The plant inventories for the
Project and for the construction of the CRIII and CWB & IECL projects are
listed in Appendix 4.2 for normal daytime.
The plant inventory list has been vetted and confirmed by the Engineer
as being practical and practicable in completing the works within scheduled
timeframe. The powered mechanical
equipment adopted for the CRIII and CWB construction tasks are in accordance
with the CRIII EIA Report and the CWB & IECL EIA Report. The construction activities considered in the
assessment during each quarter for each NSR are presented in Appendix 4.3.
Construction Noise During Restricted Hours
4.5.11
The WDII construction programme
takes into account the likelihood that the contractor will, if permitted, undertake
dredging, seawall construction, the cross harbour water mains marine works and
the sewage outfall marine works over a 16-hour working day (that is, from 0700
to 2300 hours). 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 12-hour working day (that is,
from 0700 to 1900 hours). However, where
necessary, for example to minimise traffic impacts due to road diversion works,
diversion of existing services 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:
Marine plant activities:
(i)
dredging of reclamation areas
and seawalls
(ii)
seawall trench filling
(iii)
seawall construction
(iv)
filling behind seawalls
(v)
construction of new submarine
cross harbour water mains
(vi)
construction of new submarine
sewage outfall
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
(viii)
new Hung Hing
Flyover connection to existing Victoria Park Road.
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, the potential noise impacts of
construction works proposed within restricted hours are not formally assessed
within this EIA. However, in order to
facilitate the efforts of the project proponent to avoid any potentially
adverse noise impacts, an indicative assessment is undertaken at representative
NSRs. The proposed plant inventory for construction
works during restricted hours and the assessment during each quarter are listed
in Appendices 4.4 and 4.5, respectively.
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 is based on projected peak hour flows for the worst year within 15
years after opening of the road. The
roads proposed under the WDII project are scheduled to open in 2012. Therefore, the traffic data for year 2027,
which has been endorsed by Transport Department (see Appendix 4.9), is adopted
for the assessment. Since traffic flows
along the major roads during the peak hour in the morning session are generally
higher than that in the afternoon session, the morning peak hour traffic flows
were used for modelling. The projected
2027 am peak hour traffic flows are presented in Figure 3.3.
4.5.15
Traffic speeds for the proposed
Trunk Road system based on the Updated Design Memorandum of the CWB & IECL() are adopted and summarised as
follows:
Road Speed
Limit
Trunk Road 80
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 assumed to be 50 km per hour except the IEC and Rumsey Street Flyover, which has been assumed to be 80 km
per hour for assessment purposes. The
speed limit of Road P1/P2 will be 50 km per hour. According to the “Central-Wan Chai Bypass & IECL Link Project Review Study Updated
Design Memorandum”, a friction course (porous asphalt) would be used on the
expressways or trunk roads with anticipated speed of 80 km per hour or above as
recommended in TPDM Volume 2 Chapter 6 Clauses 6.3.1.4 – 6.3.1.7 and Road Note
5. In this assessment, friction course
(porous asphalt) is assumed on the Island Eastern Corridor, Rumsey
Street Flyover, and the new roads (CWB & IECL) where the speed is 80 km per
hour, excluding the tunnel section of CWB.
No low noise road surfacing materials will be provided for Roads P1 and
P2.
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 three different elevations (that is,
1st floor, mid-floor and top floor). A
sample of modelling listing file is included in Appendix 4.7.
4.5.18
Three ventilation buildings for
the CWB tunnel, East Ventilation Building (EVB), Central Ventilation Building
(CVB) and Western Ventilation Building (WVB) are proposed along the CWB &
IECL. Their locations are shown in
Figure 4.3.
4.5.19
Potential noise impacts from
the ventilation buildings with exhaust fans would be expected at the sensitive
receivers. The fixed plant noise impact
arising from these ventilation buildings has been assessed in accordance with
the IND-TM.
4.5.20
According to Final Working
Paper on Tunnel EM&A System (WP03) of CWB & IECL Design and
Construction Assignment in November 2000 and information provided by the
Ventilation Engineer, 5 duty plus 2 standby exhaust fans are proposed for EVB. Three duty plus 2 standby exhaust fans and 3
duty plus 1 standby fans are proposed for CVB and WVB, respectively. Table 4.9 summarises the numbers of exhaust
fans required for proposed ventilation buildings during normal condition.
Table 4.9 The Number of Exhaust Fans required for
the Proposed Ventilation Buildings during Normal Condition
|
Ventilation Building
|
Fan
Capacity (m3 s-1)
|
Number
of Exhaust Fans Required
|
|
East
Ventilation Building
|
190
100
|
3 (+1 standby)
|
|
Central
Ventilation Building
|
100
90
|
2 (+1 standby)
|
|
Western
Ventilation Building
|
140
|
3 (+1 standby)
|
4.5.21 It is assumed that all duty exhaust fans are operated at each
ventilation building in the assessment.
Screening corrections from other buildings / structures and directivity
have also been excluded in the assessment.
All the exhaust fans installed in each ventilation buildings will be
provided with silencers. Since the use
of silencers will flatten the frequency band of the exhaust fan, no tonality
correction is considered in the calculation.
Helicopter Noise
4.5.22
The proposed temporary and
permanent helipads will be located at the Wan Chai
PCWA and next to the HKCEC Extension, respectively. They 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. According to information
provided by the Government Flight Services (GFS), only new types of helicopter,
Eurocopter AS-332 L2 (Super Puma) and Eurocopter EC 155B, which will be used after 2003, will
operate at these helipads.
4.5.23
As confirmed by GFS, there will
be no designated approach route and take-off route for both temporary and
permanent helipads. However, they advise
that the helicopters will generally fly along the coastline to approach the
landing pads.
4.5.24
As the new types of helicopters
will only arrive in Hong Kong by September 2001, no monitoring results for
these types of helicopters have been recorded in Hong Kong. The noise level data for these helicopters,
as supplied by the manufacturer, is attached in Appendix 4.10. Maximum flyover noise levels of AS 332 L2 at
an elevation of 152 m above ground varies from 80.4 to 83.1 dB(A) during
take-off, approach and overflight. The flyover noise levels of EC 155B are reported
to be lower than AS 332 L2. Therefore,
this assessment has been undertaken based on the noise level associated with an
AS 332 L2 helicopter as a conservative approach.
4.5.25
The closest NSRs
to the helipads are selected for assessment.
The calculation is based on the spherical spreading of the sound waves
and atmospheric absorption is not considered.
Construction
Phase
4.6.1
The scope of this Project
includes reclamation along the Wan Chai and Causeway
Bay shorelines; construction of the entrusted CWB tunnel structures;
construction of the proposed Road P2 and associated connecting roads and local
access roads, Road P2 flyover and Hung Hing Road
flyover; waterfront facilities; and entrusted foundation works for the CVB and EVB
and Administration Building. Potential
construction impacts of the Project may arise from the following activities and
operations:
·
dredging works and seawall
construction, involving barges, tug boats and dredgers;
·
filling, involving barges, tugs
and compaction activities;
·
demolition of some existing
waterfront facilities such as Wan Chai Ferry Pier and
the existing Hung Hing Road Flyover;
·
road formation and earthworks,
and road pavements;
·
tunnel construction (entrusted
by the CWB & IECL project);
·
drainage culvert construction;
·
reprovisioning of infrastructure, services and utilities.
4.6.2
The construction works for the
CWB & IECL project, the CRIII project and construction of Causeway Bay
Flyover will also contribute to the cumulative construction noise impacts.
Operational
Phase
4.6.3
Operational phase impacts will
arise from the following operations:
·
road traffic noise;
·
ventilation shaft noise;
·
helicopter noise.
4.6.4
Road traffic noise will arise
from "New" roads constructed under the Project as well as cumulative
traffic noise from the CWB & IECL roads.
It is expected that the traffic noise impact arising from proposed new
roads in the Project would not be the major contribution to the overall traffic
noise levels at most of the sensitive receivers.
4.6.5
Ventilation shaft noise
affecting sensitive receivers in the Project area may arise from the CWB
ventilation buildings (CVB and EVB).
Account is also taken of the proposed NIL ventilation shafts at
Exhibition Station.
4.6.6
Potential noise impacts may
arise from both the temporary and the permanent helicopter landing pads which
are proposed at the Wan Chai PCWA and to the
north-east of HKCEC Extension, respectively.
4.7
Prediction and Evaluation of
Environmental Impacts
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 places where unaided voice communication is
required) are predicted at representative NSRs in the
absence of mitigation measures. Details
of construction noise calculations and results are presented in Appendix
4.3. Results show that the predicted
noise levels related to the construction works of WDII project at
representative NSRs are in the range of 59 to 89 dB(A).
A summary of the unmitigated construction noise levels of the
representative NSRs during normal daytime working
hours within the WDII construction period is listed in Table 4.10. Noise mitigation measures are therefore
required to reduce noise levels to the stipulated standard.
Table 4.10 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(1)
(0700 to 1900 on Monday to Saturday excluding general holiday) (dB(A))
|
|
N1
|
60 – 78
|
|
N2
|
68 – 85
|
|
N3
|
61 – 89
|
|
N4
|
62 – 83
|
|
N5
|
62 – 81
|
|
N8
|
60 – 81
|
|
N9
|
72 – 77
|
|
N11
|
74 – 85
|
|
N14
|
66 – 81
|
|
N16
|
67 – 83
|
|
N18
|
66 - 86
|
Note: (1) For normal daytime working hours, the noise
criterion for N2 and N3 is 70 dB(A). The
criterion for other NSRs is 75 dB(A).
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 excavation works and laying new submarine and landside
pipelines. These are not major noise
generating activities. The NSRs close to the construction site at Tsim
Sha Tsui are the Hong Kong
Space Museum and the Museum of Arts.
Since they have blank facades / fixed windows and are provided with
central air conditioning (ie 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 20 representative NSRs
including existing residential dwellings, performing art centres and one
temple. In the unmitigated scenario, low
noise road surfacing is assumed on the existing Island Eastern Corridor, Rumsey Street Flyover and the new roads (CWB & IECL)
where the speed is 80 km per hour, and the noise mitigation measures on the CWB
& IECL as proposed in the EIA Report of the CWB & IECL are also
incorporated. The proposed direct
mitigation measures (DMMs) are as follows:
·
a 107 m long semi-enclosure for
the eastbound carriageway of IECL (CH4883 – CH4990);
·
a 57 m long semi-enclosure for
the westbound carriageway of IECL (CH4883 – CH4940);
·
a 113 m long and 7 m high
vertical barrier, located at the edge of the parapet of the westbound
carriageway of IECL (CH4770 – CH4883);
·
a 210 m long and 7 m high
vertical barrier located at the edge of the parapet of the Slip Road J (CH350 -
CH560);
·
a 139 m long and 5.5 m high
vertical barrier, located at the edge of the parapet of the westbound
carriageway of IECL (CH4116 – CH4255);
·
a 140 m long and 4 m high
vertical barrier, located at the edge of the parapet of the westbound
carriageway of IECL (CH4630 – 4770);
·
a 81 m long cantilevered
barrier (5.5 m high vertical barrier with 2 m cantilever length at 45 degrees
to the horizontal), located at the central divider of IECL (CH4802 – CH4883);
and
·
a 259 m long cantilevered
barrier (5.5 m high vertical barrier with 2 m cantilever length at 45 degrees
to the horizontal) located at the edge of the parapet of the westbound
carriageway of IECL (CH4255 – CH4514).
4.7.4
The extent of porous asphalt
road surfacing and the proposed DMMs mentioned above
are shown in Figures 4.2 and 3.4, respectively.
The recommended barriers can be in the form of concrete or transparent
panels; details would be finalised in the design stage of the CWB & IECL
Project.
4.7.5
The predicted mitigated results
are presented in Appendix 4.6 and the results are discussed in the following
paragraphs.
Wan Chai Area
4.7.6
Results show that noise exceedences are predicted at NSRs
N1 to N7 by 1 to 13 dB(A). The noise exceedences at NSRs N1, N4 to N7
are mainly attributed to the existing roads.
The noise levels of ‘New’ roads are less than 70 dB(A) and their contribution
to the overall noise levels are less than 1.0 dB(A). Direct mitigation measures on ‘New’ roads are
not required as they would not be effective in improving the noise environment
at the sensitive receivers.
4.7.7
The noise exceedences
at N2 and N3 are mainly attributed to the existing roads and ‘New’ roads. However, as it is known that NSRs N2 and N3 are equipped with central air-conditioning
systems and noise insulated facilities, no adverse traffic noise impacts are
expected at the indoor environment of these NSRs.
Causeway Bay Area
4.7.8
The predicted noise levels at
all NSRs (that is, N8 – N19), except the future NSR
N20, exceed the traffic noise criterion of 70 dB(A). However, the noise exceedence
is mainly attributed to the existing roads and ‘New (Others)’ roads. The ‘New’ road noise contribution to the
overall noise level is less than 1.0 dB(A) and the ‘New’ road noise levels at
these NSRs are all below 70 dB(A). Hence, direct mitigation measures on ‘New’
roads are not required as they would not effective in improving the noise
environment at the sensitive receivers.
Ventilation Shaft Noise
4.7.9
Since the exhaust 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) in the
assessment according to EIAO-TM requirement.
It is assumed all duty exhaust fans are operated for each ventilation
building during the assessment. As the
three proposed ventilation buildings are quite far away from each other, no
cumulative fixed noise impact is determined in this case. Refer also to sections 4.2.15 and 4.2.16.
4.7.10
Taking into account the
installation of silencers at each fan exhaust, any NSRs
located within the following distances from the ventilation buildings would be
subject to an exceedence of the noise criteria of
50/55 dB(A):
Ventilation Building Distance
from the ventilation building (m)
ASR ‘B’ ASR ‘C’
EVB 78 44
CVB 45 25
WVB 44 25
4.7.11
Land uses around the proposed
ventilation buildings, within these zones of noise criteria exceedence,
are commercial, infrastructural or open space.
No adverse impacts are therefore expected. From a land use planning point of view, new
land uses in this area should take these zones of noise exceedence
into account. Detailed assessment
results are presented in Appendix 4.8.
4.7.12
According to current planning
intentions, the proposed ventilation shafts for the MTR North Island Line (NIL)
would be located near the junction of Fleming Road and Convention Ave and Tonnochy Road near Harbour Road Indoor Games Hall. The WDII planning studies anticipate that
they would be incorporated in the CDA development within these vicinities. 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 shafts would comply with the EIA-TM and NCO requirements. The separation between the ventilation shaft
at Tonnochy Road and the EVB of the CWB is about 280
m. However, in view of the cumulative
fixed noise impacts from the EVB and the NIL ventilation shaft at Tonnochy Road on the NSR (Causeway Centre) closest to the
ventilation shaft at Tonnochy Road, the NIL
ventilation shaft sound power level should not be more than 96.4 dB(A) so as to
comply with the night-time fixed noise criterion of 50 dB(A). Detailed calculation is presented in Appendix
4.8. The locations of the NIL
ventilation shafts are considered to be technically feasible in terms of noise
criteria.
Helicopter Noise
4.7.13
With reference to basic
acoustic principles and based on the monitoring results for a AS 332 L2
helicopter, a setback distance of about 69 m and 122 m to the nearest office
and residential premises is required in order to meet the EIAO-TM noise
standard of 90 dB(A) Lmax (offices) and 85
dB(A) Lmax (domestic premises) for
helicopter noise. 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 temporary helipad and
the closest NSR is about 305 m. For the
permanent helipad, the distances to the closest commercial NSR (HKCEC
Extension) and residential NSR (Causeway Centre) are 190 m and 530 m
respectively. Therefore, it is
considered that the proposed helipad locations are acceptable in terms of noise
levels.
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 plant,
erection of noise barriers and reducing on-time operation of the plant, are
appropriate to be used. The above
mitigation measures have been vetted and confirmed by the Engineer as being
practical and practicable in completing the works within scheduled
timeframe. One feasible solution is to
adopt quieter construction plant for several construction tasks during all or
part of construction years. 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 silenced PMEs are taken from the BS 5228:
Part 1: 1997, which are known to be in Hong Kong. The quiet PMEs
adopted for WDII construction activities are considered practical and
practicable in completing the works within schedule. The quiet PMEs
adopted for the CRIII and CWB & IECL construction tasks are in accordance
with CRIII EIA Report and the CWB & IECL EIA Report respectively.
4.8.3
The lists of silenced PMEs adopted in the construction tasks of WDII and CWB
& IECL during normal daytime working hours are shown in Appendix 4.2. The lists of silenced PMEs
adopted in the construction tasks of CRIII are according to CRIII EIA
Report. The following construction tasks
of WDII are considered to adopt quiet PMEs:
·
Flyover Road P2 to Fenwick Pier
near the HKAPA and the Art Centre;
·
Road P2 near the HKAPA, the Art
Centre and the HKCEC Extension;
·
HKCEC roads;
·
Local access roads near the
HKAPA and the Art Centre;
·
Wan Chai
North Public Transport Interchange;
·
Demolition of HKCEC East Bridge
(WCR2E) and West Bridge (HKCEC2);
·
Demolition of ferry structure;
·
Hung Hing
Road Flyover construction;
·
Drainage culverts in CBR1E,
CBR1W, CBR2E, WCR1, WCR2E and HKCEC2;
·
Cross Harbour water mains -
land section; and
·
Cooling water intake pipelines
in HKCEC1 near HKAPA, HKCEC2W near HKAPA and Art Centre and CBR1 near Riviera
Mansion.
4.8.4
In order to further reduce
construction noise impacts on HKAPA, movable noise barriers should be adopted
for Cross Harbour Watermains land section where the
works site is close to HKAPA; and HKCEC roads where the works sites are close
to HKCEC Extension.
4.8.5
CWB tunnel works which are
entrusted by the CWB & IECL Project to the WDII Project will require
adoption of quiet PMEs for the following tasks:
·
CWB tunnel in HKCEC1, HKCEC2E,
HKCEC2W, WCR1, WCR2E, WCR2W and WCR3W;
·
Piling, tunnel and deck
construction in the MTR tunnel crossing area near HKAPA and Art Centre.
4.8.6
The construction tasks adopting
quiet PMEs under the CWB & IECL Project itself
are listed as follows:
·
Demolition of existing IEC
structure, bridge foundation, deck formation, road formation and earthworks and
road paving at the IECL section;
·
Tunnel buildings.
4.8.7
Apart from quiet PMEs, other mitigation measures as proposed in the CWB
& IECL EIA Report such as movable noise barriers, reduction in number of PMEs and on-time operation of some PMEs
while near NSR N18 during construction of IECL are considered in the mitigated
scenario. Mitigation measures including
movable noise barrier and reduction in number of PMEs
are also adopted near NSR N1 during construction of CWB Tunnel in HKCEC2.
4.8.8
According to information
provided by Highways Department, the construction noise levels arising from the
construction of Causeway Bay Flyover at the closest NSRs
will comply with the construction noise criteria with the implementation of
mitigation measures.
4.8.9
As shown in Appendix 4.3, with
the use of quiet equipment, the overall noise levels at NSRs
would be reduced by 1 to 11 dB(A), depending
on the type of construction activities.
The predicted construction noise levels arising from the WDII project at
all representative NSRs, except NSRs
N2 and N3, would comply with the EIAO-TM construction noise criteria.
4.8.10
The predicted noise levels at NSRs N2 (Art Centre) and N3 (HKCEC) still exceed the 70 dB(A) criterion by 1 to 12 dB(A)
during some construction periods.
However, central air-conditioning systems and noise insulation
facilities have been provided at these NSRs. In addition, as they do not rely on openable windows for ventilation, no adverse noise impacts
are expected for their indoor environment.
A summary for mitigated noise levels during normal daytime working hours
at representative NSRs is presented in Table 4.11.
Table 4.11 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 Hours
(0700 to 1900 on Monday to Saturday excluding general holiday) (1)
(dB(A))
|
|
N1
|
60 – 70
|
|
N2
|
68 – 79
|
|
N3
|
61 – 82
|
|
N4
|
62 – 75
|
|
N5
|
62 – 73
|
|
N8
|
60 – 74
|
|
N9
|
67 – 75
|
|
N11
|
67 – 75 (2)
|
|
N14
|
66 – 75
|
|
N16
|
60 – 75
|
|
N18
|
59 – 75
|
Note: (1) For normal daytime working hours, the noise
criterion for N2 and N3 is 70 dB(A). The
criterion for other NSRs is 75 dB(A).
(2) According to information provided by Highways
Department, the construction noise impacts of the Causeway Bay Flyover project
would be mitigated through proper implementation of appropriate noise control
measures to ensure the noise levels comply with construction noise standards.
Traffic Noise
4.8.11
As mentioned in Sections 4.7.6
to 4.7.8, no adverse road traffic noise impacts at the representative NSRs are attributed to the ‘New’ roads. Therefore, no direct mitigation measures are
recommended on ‘New’ roads.
Ventilation Shaft Noise
4.8.12
As mentioned in Section 4.7.11,
there are no NSRs which will be affected by noise
from the CWB ventilation buildings.
Mitigation measures are not required.
Helicopter Noise
4.8.13
As mentioned in Section 4.7.13,
adverse noise impacts from the proposed temporary and permanent helipads are
not expected at the NSRs. Mitigation measures are not required.
Construction Noise
4.9.1
With the implementation of the
above-mentioned mitigation measures, the construction noise levels at all
representative residential NSRs are predicted to
comply with the noise standards stipulated in the EIAO-TM. Construction noise impacts are not expected
at the performing art centres which have noise insulation facilities. Residual impacts are therefore not
anticipated.
4.9.2
In
addition to the above-mentioned mitigation measures, the good site practices
listed below should be adopted by all the Contractors to further ameliorate the
noise impacts. Although the noise
mitigating effects are not easily quantifiable and the benefits are specific to
the site and operating conditions, good site practices are easy to implement
and do not impact upon the works schedule.
·
Only
well-maintained plant should be operated on-site and plant should be serviced
regularly during the construction program.
·
Silencers
or mufflers on construction equipment should be utilised and should be properly
maintained during the construction program.
·
Mobile
plant, if any, should be sited as far away from NSRs
as possible.
·
Machines
and plant (such as trucks) that may be in intermittent use should be shut down
between works periods or should be throttled down to a minimum.
·
Plant
known to emit noise strongly in one direction should, wherever possible, be
orientated so that the noise is directed away from the nearby NSRs.
·
Material
stockpiles and other structures should be effectively utilised, wherever
practicable, in screening noise from on-site construction activities.
Traffic Noise
4.9.3
No impacts from the ‘New’ roads
are predicted at the representative NSRs.
Ventilation Shaft Noise
4.9.4
No noise impacts are predicted
and set back distances from the ventilation buildings have been evaluated to
ensure that only non-sensitive land uses are planned in these areas.
Helicopter Noise
4.9.5
No impacts are expected at the
representative NSRs for the proposed temporary and
permanent helipads during normal operations.
4.10
Construction Activities during
Restricted Hours
4.10.1
As mentioned in Section 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
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 is adopted in this
assessment.
4.10.2
The PMEs
for construction tasks during restricted hours and assessment results are
presented in Appendices 4.4 and 4.5, respectively. Results indicate that noise exceedences of 65 dB(A) are predicted at NSRs. A summary of
unmitigated noise levels at representative NSRs is
presented in Table 4.12.
Table 4.12 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) (dB(A))
|
|
N1
|
55 – 64
|
|
N2
|
62 – 69
|
|
N3
|
59 – 76
|
|
N4
|
59 – 68
|
|
N5
|
58 – 66
|
|
N8
|
57 – 68
|
|
N9
|
57 – 72
|
|
N11
|
60 – 69
|
|
N14
|
58 – 70
|
|
N16
|
59 – 74
|
|
N18
|
57 – 71
|
4.10.3 Mitigation measures will be required to reduce these noise
levels. It is recommended to reduce the
number of PMEs for following construction activities:
·
Dredging at CBR1E, CBR1W,
CBR2E, CBR2W, WCR2E and WCR2W;
·
Seawall construction at CBR1E,
CBR1W, CBR2E, CBR2W, WCR2E, WCR2W and WCR3;
·
Filling behind seawall at
CBR1E, CBR1W, CBR2E, CBR2W, WCR1, WCR2E, WCR2W, WCR3 and PCWA Basin.
4.10.4
In addition, adoption of quiet
plant for seawall construction at CBR1E & CBR1W and reduction of on-time
percentage for some plant undertaking the following activities are assumed in
order to alleviate the construction noise impacts on NSRs
N16 and N18:
·
Dredging and seawall
construction at CBR1E close to NSR N16;
·
Seawall construction at CBR1W
close to NSRs N16 and N18; and
·
Seawall construction at CBR1E
close to NSR N18.
4.10.5
Predicted noise levels after
mitigation at representative NSRs are shown in
Appendix 4.5. A summary of mitigated
noise levels at representative NSRs is presented in
Table 4.13.
Table 4.13 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) (dB(A))
|
|
N1
|
53 – 63
|
|
N2
|
62 – 65
|
|
N3
|
59 – 69
|
|
N4
|
59 – 65
|
|
N5
|
58 – 65
|
|
N8
|
54 – 65
|
|
N9
|
57 – 65
|
|
N11
|
55 – 64
|
|
N14
|
53 – 64
|
|
N16
|
59 – 65
|
|
N18
|
52 – 65
|
4.10.6 With the adoption of the recommended mitigation measures, the
predicted noise levels at all residential NSRs would
comply with the construction noise criterion of 65 dB(A) during restricted
hours. In applying for a Construction
Noise Permit, the Applicant (that is, 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. Noise exceedences for evening works are still predicted at NSR N3
(HKCEC Extension) at certain periods (from October 2005 to September 2006 and
from April 2007 to September 2007 based on the latest programme). Under these circumstances, working in
restricted hours for most areas of reclamation, except those near HKCEC
Extension, are found to be possible.
Mitigation measures such as reduction in PMEs
and reduction of on-time percentage for plant working close to the HKCEC
Extension will be required to reduce noise levels to acceptable limits in this
area.
4.10.7
The above assessment
demonstrates that the predicted noise levels arising from the anticipated
construction activities can comply with the relevant Acceptable Noise Levels
(except at NSR N3 at certain periods) as stipulated in the GW-TM and will not,
in themselves, impose adverse noise impacts on NSRs. If the Contractor considers that there is a
need to carry out construction works during restricted hours, a Construction
Noise Permit should be obtained from the Noise Control Authority prior to
commencement of such works (also see section 4.2.5). 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.
4.11
Environmental Monitoring and
Audit
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 programme are
provided in the stand-alone EM&A Manual.
Operational Noise
4.11.2
No residual impacts from
traffic noise, ventilation shaft noise and helicopter noise are expected at the
NSRs.
Therefore, no monitoring is required during operational phase.
4.12
Conclusion
Construction Phase
4.12.1 This assessment has predicted the WDII
construction noise impacts during normal daytime, taking into account other
concurrent projects including the CRIII and CWB & IECL projects and the
Causeway Bay Flyover project. With the
use of silenced equipment and movable barriers for WDII construction tasks and
implementation of the noise mitigation measures proposed in the CRIII and CWB
& IECL EIA Reports, the noise levels at most of the representative NSRs would comply with the construction noise
criteria. Noise exceedences
are still predicted at performing art centres.
However, these NSRs are equipped with central
air-conditioning systems and good noise insulation facilities. In addition, they do not rely on openable windows for ventilation. No adverse noise impacts are therefore
expected at the indoor environment of these NSRs.
4.12.2 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. Insignificant construction noise impacts are
expected on the indoor environment of the NSRs such
as the Hong Kong Space Museum and the Museum of Arts, which are close to the
construction site at Tsim Sha
Tsui, as they have blank facades / fixed windows and
are provided with central air conditioning, and therefore do not rely on openable windows for ventilation.
4.12.3 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 reduction of plant numbers, adoption
of quiet plant and reduction of on-time percentage for some equipment, the
predicted noise levels at all representative residential NSRs
would comply with construction noise criterion of 65 dB(A). Noise exceedences
of the 65 dB(A) criterion at HKCEC are still predicted at certain period, for plant working close to the HKCEC Extension. 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.
4.12.4
A
construction noise EM&A is recommended to check the compliance of the noise
criteria during normal daytime working hours.
Operational Phase
4.12.5
The potential road traffic
noise impacts have been assessed based on the worst case traffic flows in 2027,
taking into consideration of the recommended mitigation measures on the IECL
according to the CWB & IECL EIA Report.
The noise levels at most of the NSRs are
predicted to exceed the EIAO-TM traffic noise criteria. However, these noise exceedences
are mainly attributed to the existing roads and the IECL. Noise exceedences
attributed to the IECL are reported separately in the CWB&IECL EIA
Report. The ‘New’ road noise
contributions to the overall noise level are negligible (that is, less than 1.0
dB(A)).
4.12.6
In addition, some NSRs such as the Art Centre and HKCEC Extension are
equipped with central air-conditioning systems and noise insulation facilities,
and they do not rely on openable windows for
ventilation. Therefore, adverse traffic
noise impacts are not expected at the indoor environment of these NSRs.
4.12.7
No adverse impacts from
helicopter noise and fixed noise sources including ventilation shaft noise from
the CWB ventilation buildings are anticipated at the existing and planned NSRs.