6.1
Potential airborne noise impacts likely arising during the
construction and operational phases of the Project have been
evaluated and mitigation measures have been recommended in this section.
Environmental Legislation,
Standards and Guidelines
6.2
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
6.3
The Noise Control Ordinance, Cap. 400 (NCO) and
Environmental Impact Assessment Ordinance, Cap. 499 (EIAO) provide the
statutory framework for noise control.
Assessment procedures and standards are set out in the following
Technical Memoranda (TMs):
Ÿ Technical Memorandum on Environmental Impact
Assessment Process (EIAO-TM)
Ÿ Technical Memorandum on Noise from Construction
Work other than Percussive Piling (GW-TM)
Ÿ Technical Memorandum on Noise from Percussive
Piling (PP-TM)
Ÿ Technical Memorandum on Noise from Construction
Work in Designated Areas (DA-TM)
Ÿ Technical Memorandum for the Assessment of Noise
from Places Other Than Domestic Premises, Public Places or Construction Sites
(IND-TM)
6.4
As a general principle for noise assessment as stated in the
associated TMs, “any premises or place shall, however, be considered to be a
Noise Sensitive Receiver (NSR) only when it is in use for its intended
purpose”.
6.5
Percussive piling is governed under the PP-TM and a
construction noise permit (CNP) is required in order to carry out such
work. As the issuance of a CNP by the
Noise Control Authority would depend on the compliance of percussive piling
noise impact with the limits set out within the PP-TM, the assessment of this
type of noise would not be covered in the EIA report.
Construction Noise during Non-restricted Hours
6.6
Daytime general construction works (excluding percussive
piling) between the hours 0700 – 1900 on weekdays, i.e. non-restricted hours,
is controlled under the EIAO. Annex 5 of
the EIAO-TM sets out the construction noise assessment limits, which are Leq(30
min) 75dB(A) for domestic premises, hotels and hostels; and Leq(30 min) 70dB(A) for schools
during normal hours (65dB(A) during examination periods) and all other places
where unaided voice communication is required. The criteria are summarized in Table 6.1.
Table 6.1 Air-borne
Daytime Construction Noise Criteria
|
Uses |
Daytime Noise Criteria, (Leq, 30min,
dB(A)) |
|
|
Domestic premises |
75 |
|
|
Educational Institution |
70 |
|
|
Educational Institution (during examination) |
65 |
|
Note:
The above standards apply to uses which rely on opened windows for ventilation
Construction Noise Standards during Restricted Hours
6.7
All days
between 1900 and 0700 hours and the whole day on Sundays and public holidays,
activities involving the use of Powered Mechanical Equipment (PME) for the
purpose of carrying out construction work are prohibited unless a Construction
Noise Permit (CNP) has been obtained. A
CNP may be granted in cases where the noise can be contained within the
Acceptable Noise Level (ANL) at the NSRs.
ANLs are assigned depending upon the Area Sensitivity Ratings. The corresponding basic noise levels (BNLs)
for evening and night-time periods are given in Table 6.2.
Table 6.2 Construction
Noise Criteria for Activity other than Percussive Piling during Restricted
Hours
|
Time Period |
ANL on Different Area Sensitivity Rating During Restricted Hours (Leq,
30min, dB(A)) |
||
|
Area Sensitivity Rating A |
Area Sensitivity Rating B |
Area Sensitivity Rating C |
|
|
All
days during evening (1900 to 2300 hours),
and general holidays (including Sundays) during the day-time evening (0700 to
2300 hours) |
60 |
65 |
70 |
|
Night
(2300 to 0700 hours) |
45 |
50 |
55 |
6.8
Despite any
description or assessment made in this EIA Report on construction noise
aspects, there is no guarantee that a 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 TMs issued under the NCO. The Noise Control Authority
will take into account contemporary conditions/ situations of adjoining land
uses and any previous complaints against construction activities at the site
before deciding whether to grant a CNP.
Nothing in the EIA Report should bind the Noise Control Authority in
making its decision. If a CNP is to be
issued, the Noise Control Authority should include in the permit any condition
it considers appropriate. Failure to
comply with any such conditions will lead to cancellation of the CNP and
prosecution under the NCO.
6.9
Under the
DA-TM, 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 Project falls within
DA). The SPME includes hand-held
breaker, bulldozer, concrete lorry mixer, dump truck and hand-held vibratory
poker. The PCW are:
Ÿ Erecting or dismantling of formwork or
scaffolding;
Ÿ Loading, unloading or handling of rubble, wooden
boards, steel bars, wood or scaffolding material; and
Ÿ Hammering
6.10
In general,
it should not be presumed that a CNP would be granted for carrying out PCW
within a designated area during restricted hours. The CNP may be granted for the execution of
construction works during restricted hours involving the use of PME and/ or
SPME if the relevant Acceptable Noise Levels and criteria stipulated in the
GW-TM and DA-TM can be met. The construction noise criteria are presented in Table 6.3.
Table 6.3 Construction Noise Criteria for
SPME
|
Time Period |
Basic Noise Level
(BNLs) |
||
|
Area Sensitivity Rating A |
Area Sensitivity Rating B |
Area Sensitivity Rating C |
|
|
All
days during evening (1900 to 2300
hours), and general holidays (including Sundays) during the day-time evening
(0700 to 2300 hours) |
45 |
50 |
55 |
|
Night
(2300 to 0700 hours) |
30 |
35 |
40 |
Airborne Rail Noise during Operational Phase
6.11
The EIAO-TM and IND-TM stipulate the appropriate ANL for
airborne rail noise. The ANLs are
dependent on Area Sensitivity
Ratings of the Noise Sensitive Receivers (NSRs) and are shown in Table 6.4. The EIAO-TM also specifies the noise limit of
Lmax to be 85 dB(A)
during night-time. In accordance with the Hong Kong Planning Standards and
Guidelines (HKPSG), a 24-hour averaged noise level of 65dB(A)
Leq,24hr has been specified.
Table 6.4 Airborne
Rail Noise Criteria
|
|
ANL on Different Area Sensitivity Rating for Air-borne
Operational Noise, (Leq, 30min, dB(A)) |
||||||
ABNSR Description |
Daytime and Evening time (0700 to 2300 hrs) |
Night-time |
|||||
|
A |
B |
C |
A |
B |
C |
||
|
Domestic premises, hotel, hostel and hospitals |
60 |
65 |
70 |
50 |
55 |
60 |
|
|
Churches, School, medical clinics, and performing arts centre [b]
|
60 |
65 |
70 |
[a] |
|||
Notes:
[a] No sensitive use/activities during this period.
[b] Churches, School, performing arts centre,
Clinics are considered to be noise sensitive during daytime and evening time
only.
Fixed Plant Noise during Operational Phase
6.12
Fixed plant noise sources are controlled by Section 13 of
the NCO. For the assessment of impacts
from fixed noise sources, the Area Sensitivity
Ratings are determined based on the best available information at this
stage. Nothing in this report shall bind the Noise Control Authority
in the context of law enforcement against any fixed sources being assessed.
6.13
More stringent criteria for fixed plant noise impact
recommended in the EIAO-TM for planning purposes are as follows (Table 6.5):
Ÿ 5dB(A) below the appropriate ANL set out in the
IND-TM (the ANL-5dB(A) criterion); or
Ÿ The prevailing background noise level where the
prevailing background noise level is lower than 5dB(A)
below the appropriate ANL (i.e. ANL - 5dB(A)).
Table 6.5 Fixed
Plant Noise Criteria
|
|
Fixed Plant Noise for Different Area Sensitivity Rating, (Leq, 30min, dB(A)) |
|||||
|
Time Period |
ANL, dB(A) |
ANL-5, dB(A) |
||||
|
A |
B |
C |
A |
B |
C |
|
|
Day (0700 to 1900 hours) |
60 |
65 |
70 |
55 |
60 |
65 |
|
Evening (1900 to 2300 hours) |
60 |
65 |
70 |
55 |
60 |
65 |
|
Night (2300 to 0700 hours) |
50 |
55 |
60 |
45 |
50 |
55 |
6.14
The above-mentioned second criteria would generally apply to
areas with low prevailing noise levels such as suburban areas. For areas without major nearby noise sources
such as road and rail traffic, NSRs adjacent to these locations would be
subject to low prevailing noise levels which could be lower than the ANL-5dB(A) criterion. In
order to determine the appropriate criteria for noise assessment, background
noise measurements at representative NSRs were conducted. For those NSRs which are found to experience
to prevailing noise levels lower than the ANL-5dB(A)
criterion, fixed plant noise impact would be assessed against the prevailing
background noise levels.
Description of the Existing
Environment
6.15
The alignment of the Project is located at well-developed
area. The surrounding land uses mainly
comprise a mixture of commercial, Government/Institution/Community and
residential uses. Dominant noise sources were identified as the road traffic
noise from Princess Margaret Road, Hong Chong Road, Chatham Road South, Chatham
Road North, Cheong Tung Road South, Hung Luen Road
and Cross Harbour Tunnel, etc. Key sources of noise impact are summarised in Table 6.6.
Table 6.6 Key
Noise Sources to the Existing Environment
|
Existing Noise Sources |
Affecting Areas |
|
Road Traffic Noise from |
Areas around Oi Man Estate and |
|
Princess Margaret Road, Hong Chong Road, Cross Harbour Tunnel, Chatham
Road South, Chatham Road North and associated slip roads |
Areas around Parc Palais,
|
|
|
Areas around The |
|
|
Areas around |
|
Salisbury Road, Hung Hom Bypass, Hung Luen Road, Cheong Tung Road South and associated slip
roads |
Areas around The Metropolis Residence, |
6.16
Several noise measurements have been conducted from January
to April 2009 to identify the prevailing noise levels. As observed during the measaurements, existing noise was dominated by traffic
noise from major roads. Railway noise
from the East Rail Line was also audiable at some
locations. The prevailing noise levels were listed in Table 6.7.
Table 6.7 Prevailing
Noise Levels
|
Areas |
Time Period |
Prevailing Noise
Level, dB(A) Leq, 30 mins |
|
Areas around Oi Man Estate &
Carmel Secondary School facing |
Day & Evening |
>70dB(A) |
|
Night |
>60dB(A) |
|
|
Areas around Parc Palais,
Wylie Court and Wing Fung Building facing Princess
Margaret Road and Hong Chong Road |
Day & Evening |
>70dB(A) |
|
Night |
>60dB(A) |
|
|
Areas around Parc Palais,
facing |
Day & Evening |
>70dB(A) |
|
Night |
>60dB(A) |
|
|
Areas around The Hong Kong Polytechnic University facing |
Day & Evening |
>70dB(A) |
|
Night |
>60dB(A) |
|
|
Areas around |
Day & Evening |
>70dB(A) |
|
Night |
>60dB(A) |
|
|
Areas around Harbour Plaza Metropolis and Harbourfront
Horizon facing |
Day & Evening |
>70dB(A) |
|
Night |
>60dB(A) |
|
|
Areas around The Metropolis Residence facing existing HUH |
Day & Evening |
>65dB(A) |
|
Night |
>55dB(A) |
6.17
Existing and planned/committed noise sensitive receivers
have been identified based on Survey and Mapping Office drawings of the
assessment areas (i.e.
Table 6.8 Representative
Noise Sensitive Receivers/Assessment Point for Air-borne Noise Assessment
|
NSR ID |
Description |
Land Use |
No. of storey |
|
Air-borne Construction Phase |
|||
|
OM1 |
Shun Man House, Oi
Man Estate |
Residential |
23 |
|
OM2 |
Parc Palais, Block 6 |
Residential |
24 |
|
OM3 |
Parc Palais, Block 1 |
Residential |
24 |
|
OM4a |
(All rooms are air-conditioned and soundproof windows) |
Educational Institution |
5 |
|
HH1 |
|
Residential |
20 |
|
HH2 |
|
Residential |
8 |
|
HH4 |
|
Residential |
42 |
|
HH7 |
The Metropolis Residence (with centralised fresh-air supply) [a] |
Service Apartment |
18 |
|
HH9 |
Harbourfront Horizon (with centralised fresh-air supply) [b] |
Commercial/ Service Apartment |
22 |
|
Air-borne Operational Phase (Rail Noise) |
|||
|
OM |
Shun Man House (South Block), Oi Man Estate |
Residential |
23 |
|
OM1b |
Shun Man House (North Block), Oi Man Estate |
Residential |
23 |
|
OM2 |
Parc Palais, Block 6 |
Residential |
24 |
|
OM4b |
(All rooms are air-conditioned
and soundproof windows) |
Educational Institution |
5 |
|
HH1 |
|
Residential |
20 |
|
HH2 |
|
Residential |
8 |
|
Air-borne
Operational Phase (Fixed Plant Noise) |
|||
|
HH4 |
|
Residential |
42 |
|
HH7 |
The Metropolis
Residence, Tower 2 (with centralised fresh-air supply) [a] |
Service Apartment |
18 |
|
HH9b |
Harbourfront Horizon (with centralised fresh-air supply) [b] |
Commercial/ Service Apartment |
22 |
Note:
[a] Metropolis Residence is a service
apartment and shall not rely on openable windows for
ventilation. Nonetheless, for conservative consideration that occupier might
open window under special circumstances, this premise has been considered as an
assessment point.
[b] Harbourfront
Horizon shall not rely on openable windows for
ventilation. Nonetheless, for conservative consideration that occupier might
open window under special circumstances, this premise has been considered as an
assessment point.
Table 6.9 Area
Sensitive Rating for Representative Noise Sensitive Receivers/Assessment Point
|
NSR ID |
Description |
Type of Area Containing NSR |
Influencing Factor |
Degree of Influence |
Area Sensitive Rating |
|
Air-borne Construction Phase (Construction Works in Restricted Hours) |
|||||
|
OM1 |
Shun
Man House, Oi Man Estate |
Mixed area with high density residential and GIC uses[a] |
Directly facing heavy trafficked road, |
Direct
Influence |
C |
|
OM2 |
Parc Palais, Block 6 |
C |
|||
|
HH1 |
|
C |
|||
|
OM3 |
Parc Palais, Block 1 |
Mixed area
with high density residential and GIC uses[a] |
Indirectly facing heavy trafficked road, |
Indirect Influence |
B |
|
Air-borne Operational Phase (Rail Noise) |
|||||
|
OM |
Shun Man House (South Block), Oi Man Estate |
Mixed area with high density residential and GIC uses[a] |
Directly facing heavy trafficked road, |
Direct Influence |
C |
|
OM1b |
Shun Man House (North Block), Oi Man Estate |
C |
|||
|
OM2 |
Parc Palais, Block 6 |
C |
|||
|
OM4a & OM4b |
|
C |
|||
|
HH1 |
Block C |
C |
|||
|
HH2 |
|
Mixed area with medium density residential and GIC uses [a] |
Directly facing heavy trafficked road, (AADT >30,000) |
Direct Influence |
C |
|
Air-borne
Operational Phase (Fixed Plant Noise) |
|||||
|
HH4 |
|
Mixed area with high density residential and GIC
uses [a] |
Directly facing heavy trafficked road, Princess Margaret Road
Link (AADT >30,000) |
Direct Influence |
C |
|
HH7 |
The Metropolis
Residence, Tower 2 (with centralised fresh-air supply) |
Mixed area with medium density
residential and GIC uses [a] |
Indirectly facing (AADT >30,000) |
Indirect Influence at high level and not Influence at low level |
B |
|
HH9b |
Harbourfront Horizon (with
centralised fresh-air supply) |
Mixed area with medium density residential and commercial
uses [a] |
Nil |
Not Influence |
B |
Notes:
[a] Under
the category of Areas Other Than Rural Area, Low-rise Residential or Urban
Area, in accordance with IND-TM.
Construction Noise
During Non-restricted Hours
6.18
The potential source of noise impact during the construction
phase of the Project would mainly be the use of PME for various construction
activities. Major construction works
would include cut
and cover works for tunnel and surface works, construction of superstructures
including ventilation shafts, modification work to HUH podium structures as
well as loading and unloading at barging point.
6.19
The key elements involved for air-borne
construction noise at different rail sections were
summarized in Table 6.10. A figure showing
the SCL (MKK-HUH) alignment and location of Portal
Table 6.10 Construction
Phase Elements for the Project (Non-restricted Hours)
|
Sections |
Key Construction Items |
Nearby Representative NSR |
|
Portal 1A (the most northern
part of the project boundary) to North
of Hung Hom Station (HUH) – using Cut & Cover
Construction Method |
• Construction of a
branch off track (and troughs and tunnels toward Chatham Road Interchange) • Construction Works Area
above ground, e.g. Associated slope works at Oi Sen
Path. |
Air-borne (AB) Construction Noise • Oi Man Estate (Shun Man House)
(OM1) • Parc
Palais Block 6 (OM2) • Parc
Palais Block 1 (OM3) • • Wylie
Court Block C (HH1) • |
|
North of HUH to |
• Construction
of the approach tunnel • Construction of
platform/station ( at existing Hung Hom podium) • Construction of
ventilation shafts at the north and south sides of HUH • Construction
Works Areas above Ground, eg. Cooling Tower • Barging
Point at Hung Hom Freight Pier |
AB Construction Noise • Royal
Peninsula Block 2 (HH4) • The Metropolis
Residence (HH7) • Harbourfront Horizon
(HH9) |
Construction Noise
During Restricted Hours
6.20
The construction programme for the Project takes into
account the likelihood that the contractor will, if permitted, undertake
construction works during restricted hour (2300 to 0700 hours) at the areas
immediately along the existing East Rail Line. This is for the safety reason
for avoiding works above or underneath the existing East Rail during the
railway traffic hours.
6.21
The activity that may be carried out during
night time which requires CNP is listed in Table 6.11.
Table 6.11 Construction Phase Elements for the
Project (Restricted Hours)
|
Sections |
Key Construction Items |
Nearby Representative NSR |
|
Portal 1A (the most northern
part of the project boundary) to North
of Hung Hom Station (HUH) |
• Construction of Noise Mitigation Structures near Portal 1A |
Air-borne (AB) Construction Noise • Oi Man Estate (Shun Man House)
(OM1) • Parc
Palais Block 6 (OM2) • Parc
Palais Block 1 (OM3) • Wylie Court Block
C (HH1) |
6.22
According to GW-TM, for any construction works planned
during the restricted hours, the Contractor will be required to apply for a CNP
from the Noise Control Authority and has the responsibility to ensure
compliance with the NCO and relevant TM. Therefore, an indicative noise
assessment in this EIA is for the evaluation of whether construction works in
restricted hours are feasible or not in the context of programming construction
work only.
Cumulative
Construction Noise Impact from Other Concurrent Project
6.23
There are some nearby projects that would have interfacing issues.
Details are discussed as follows and the locations are illustrated in Figure No. NEX2213/C/361/ENS/M50/503:
Ÿ KTE - the new Ho Man Tin Station would be
constructed by cut and cover method with operation of rock crushing plant at Hung Hom Freight Pier, the
cumulative noise contribution for the KTE construction works, including rock crushing activities have therefore been incorporated.
Ÿ SCL – Hung Hom to
Admiralty Section (SCL (HUH-ADM)) – the cumulative
impacts from works near the NOV and
Hung Hom Landfall have been included.
Ÿ SCL – Tai Wai to Hung Hom
Section (SCL (TAW-HUH)) - the tunnel sections at Hung Hom
and HUH would be constructed by cut and cover method. The cumulative construction noise
contribution has therefore been included.
Ÿ Shared barging point at Hung Hom Freight Pier – the cumulative noise contribution for
the loading/unloading has been incorporated. Based
on the latest design information, two berths will be operated until works at
the Hung Hom Landfall commence that the berth at the
tip of the freight pier will be demolished and only one berth will be used
after that.
Ÿ Improvement works for viaducts associated with the Project have been considered
as concurrent works and their contribution has been incorporated:
Ø Upgrading
Ø Upgrading of vehicular
parapets for Chatham Road Slip Road Bridge.
Ÿ
Ÿ Widening of
Rail Noise
6.24
The MLR and SP1900 trains on the existing East Rail Line
will continue to run on its existing tracks and stations until the whole SCL
comes into operation. Upon the commissioning of the SCL (HUH-ADM), the existing East
Rail Line will “switchover” to the SCL alignment, i.e. new 9-car SP1900 or
equivalent trains would run on the new alignment and new stations. Section that is open and would contribute to
rail noise to the nearby sensitive receivers is appropriately 250m long between
the Portal 1A and the
6.25
Other existing East Rail Line noise sources include:
Ÿ freight trains,
Ÿ intercity through trains and
Ÿ maintenance trains
6.26
With the rapid development of road and port facilities in
the Mainland China, the freight business at the East Rail Line has sharply
dropped. In 2009, it has been decided to
cease the freight business. Therefore,
the freight trains will not pose additional noise contribution to NSR when the
SCL is in operation.
6.27
For intercity through trains, it is expected that services
will be maintained at the existing alignment and prevailing frequency if not
less with the Express Rail Link in operation:
Ÿ No intercity train is scheduled before 0700hr peak night time;
Ÿ A maximum of one intercity movement (either uptrack or downtrack) in a half-hour period would be deployed during day-time peak hour; and
Ÿ Only one intercity train (downtrack) is scheduled during non-peak night time period.
6.28
As explained in Chapter 2, the existing Homantin Siding will be slightly modified. Three existing
tracks will be reduced to one track with spur track approaching the Hong Kong
Polytechnic University Phase 8 (HKPU Phase 8) area and the number of crossing
will be reduced. The alignment of the reprovisioned
track will also be slightly further away from the nearby residential blocks (
6.29
In general, the noise climate near Portal
Fixed Plant Noise
6.30
According to the design information, the
major fixed plant noise sources are identified as the new exhausts and intakes of
ventilation shafts at HUH and illustrated in Figure No.
NEX2213/C/361/ENS/M52/601.
Road Traffic Noise
Contribution from Realignment of Cheong Wan Road
6.31
As discussed in Chapter 1, one of
the works items is to realign the Cheong Wan Road Viaduct. This section of
6.32
Based on the latest design
information, both the traffic flow and traffic composition would not be changed
due to the road realignment. The road
traffic impact arising from the operation of the re-aligned
·
To the east of the road – the
nearest NSRs are
·
To the south and west of the
road, the nearest developments are Hong Kong Polytechnic University (HKPU),
HUH, hotel, service apartment, GIC or commercial buildings, which either do not
rely on natural ventilation or would be considered as non-noise sensitive uses.
Thus, there are no sensitive premises on these directions.
·
To the north of the road, the
nearest NSR is On Tai Mansion which more than 150m away. The building is
screened by a group of noise non-sensitive buildings, such as Universal Funeral
Parlour. The consideration on screening
and setback effect, the contribution from
6.33
Therefore, the realignment of
Summary of Noise
Source
6.34
Table 6.12 summarizes the key
elements involved in operational phase for air-borne noise at different rail
sections.
Table 6.12 Operational
Phase Elements for the Project
|
Section |
Before SCL (HUH - ADM) comes into
Operation in Yr 2020 (Using Existing East Rail Line Track and Station) |
After SCL (HUH - ADM) comes into Operation
in Yr 2020 (when the entire section from MKK to ADM in operation – mostly
underground) |
Representative NSR (Operational Phases) |
|
Portal |
AB Rail Noise Sources • Using existing MLR/SP1900 trains (same as existing East Rail
Line) • Using existing ballast tracks (above Ground) • Freight train operation to cease • Infrequent Intercity and maintenance locomotive movements, same
as the prevailing condition • Alignment of Homantin
Siding slightly further away from NSR and
the number of crossing reduced |
AB Rail Noise Sources • Using new 9-car trains of SP 1900, or equivalent • Using slab tracks at trough near • Using HUH with new platforms • Freight train operation to cease • Infrequent Intercity and maintenance locomotive movements,
expected to be same as the prevailing condition • Alignment of Homantin Siding slightly further away from NSR and the number of crossing reduced |
AB Rail Noise • Shun Man Estate (South Block), Oi Man Estate (OM1a) • Shun
Man Estate (North Block), Oi Man Estate (OM1b) • Parc Palais Bk 6 (OM2) • • Wyle Court Bk
C (HH1) • |
|
North of
HUH to HUH NOV |
AB Rail Noise Sources • Using existing MLR/SP1900 trains (same as existing East Rail
Line) • Using existing ballast track (above Ground) • Using existing HUH • Freight train operation to cease • Infrequent Intercity movement, same as the prevailing condition Fixed Source Noise Sources • New
Exhaust/Intakes at HUH in operation under SCL (TAW-HUH) Road Traffic Noise Sources • Realignment of Cheong Wan Road |
AB Rail Noise Sources • Using new 9-car trains of SP 1900, or equivalent • Using new slab
tracks (most are underground) • Using HUH with new platforms • Freight train operation to cease • Infrequent Intercity movement, expected to be same as the
prevailing condition Fixed Source Noise Sources • Exhaust/Intakes
at HUH Road Traffic Noise Sources • Realignment of Cheong Wan Road |
AB Fixed Source Noise • • The Metropolis Residence (HH7) • Harbourfront
Horizon (HH9b) AB Road Traffic Noise • • The Metropolis Residence • On |
6.35
In terms of
the operational noise impact, owing to the fact that the services at the East
Rail Line will be maintained on the existing alignment before Year 2020,
condition before 2020 remains the same as the prevailing condition, and no rail
noise assessment will be necessary for the case before Yr 2020. Thus, rail
noise impact will be focussed on the mode of operation after Yr 2020 using the
new SCL alignment.
Cumulative Operational
Noise Impact from other concurrent projects
6.36
There are three rail projects that would have interfacing issues within
the study area:
Ÿ KTE - the track will be underground and
the station will be located more than 250m away. Thus, cumulative noise impact
is not anticipated;
Ÿ SCL (HUH-ADM) – the track will be underground
and no air-borne rail noise contribution would be anticipated. Nonetheless, the
fixed source noise impact from the NOV at
the water front area has been considered as a cumulative noise source; and
Ÿ SCL (TAW-HUH) - open air railway tracks confined
between HUH and
Air-borne Noise during Construction Phase
6.37
The
methodology for the noise impact assessment is in accordance with the
procedures outlined in the GW-TM. The general approach is summarized below:
Ÿ Locate the NSRs which would most likely be
affected by noise from the construction work;
Ÿ Determine the items of Powered Mechanical
Equipment (PME) for each discrete construction activity, based on available
information or agreed plant inventories;
Ÿ Assign Sound Power Levels (SWLs) to the proposed
PME according to the GW-TM or other sources;
Ÿ Calculate distance attenuation to NSRs from
notional noise source;
Ÿ Apply corrections in the calculations such as
potential screening effects and acoustic reflection, if any;
Ÿ Predict construction noise levels at NSRs in the
absence of any mitigation measures;
Ÿ Any cumulative impact from the concurrent
construction activity within 300m; and
Ÿ Compare the cumulative noise level against the
noise criteria and propose suitable mitigation measures.
6.38
SWLs of the equipment have been made reference from Table 6
of GW-TM. Where no relevant SWL is found
in the GW-TM, reference has been made to British
Standard 5228: Part 1:2009 Noise Control on Construction and Open Sites and
previous similar studies or from measurements taken at other sites in
Air-borne Rail Noise during Operational Phase
6.39
Airborne rail noise from train movement has been predicted
in accordance with “The Calculation of Railway Noise (CRN)” published by
Department of Transport in 1995, and standard acoustical principles
and practices. The general assessment
approach is outlined below:
Ÿ Locate the NSRs which would most likely be
affected by air-borne noise from the rail operation;
Ÿ Identify the train frequency and make
appropriate frequency correction;
Ÿ Review the impact of infrequent usage of
existing intercity train / maintenance locomotive movement;
Ÿ Identify the distance from the NSR to the train
and make distance correction;
Ÿ Identify the train type and the source term of
the train;
Ÿ Identify the angle of view and make appropriate
angle of view correction;
Ÿ Incorporate Façade Correction;
Ÿ Incorporate Track Wear Correction;
Ÿ Incorporate Turnout Correction;
Ÿ Incorporate Slab Track Correction;
Ÿ Identify any barrier effect and make appropriate
barrier correction;
Ÿ Calculate the noise level from all rail
segments;
Ÿ Incorporate the noise contributions from other
railway vehicles when the train schedule is available; and
Ÿ Compare the cumulative air-borne noise level
against the noise criteria
6.40
For ease of reference,
Table 6.13
summaries the general corrections adopted in the CRN.
Table 6.13 Air-borne
Rail Noise Parameters and Correction Factors
|
Parameters |
Approach |
|
|
Train Type |
SP1900 or
equivalent, train length of 9-car |
|
|
Source Term SELref |
Train Noise:
75.3dB(A) Lmax at 130kph measured at AC Noise: 57.0
dB(A) Lmax at In
accordance with “Equation 15.21 of the
Transportation Noise Reference Book”, edited by Harris, the equation for
the calculation of Lmax is given below: SEL
= Lmax + 10log(L/V) +10.5 – 10log[(4D/(4D2+1)) + 2tan-1(1/(2D))] Where L = train
length (m); V = train speed (kph); d = Perpendicular distance from track (m);
D = d / L |
|
|
Distance Correction for Wheel/Rail Noise |
-10 log10 (d’/25),
where d’ = Slant Distance to NSR (d’>= |
|
|
Distance Correction for A/C Noise |
-10 log10 (d’/15), where d’ = Slant Distance to NSR (d’>= |
|
|
Train Frequency Effect |
+10 log10 (N),
where N = Train Frequency per 30 min per Direction |
|
|
Ground Effect |
Hard Ground, no
absorption |
|
|
Air Absorption
Effect |
Nil (Close
proximity with NSR in HK environment) |
|
|
Barrier Effect |
Shadow Zone: -21dB(A) for δ > 2.5m where δ is the Path Difference in metre -7.75 log10
(5.2 + 203 δ) dB(A) for 0≤ δ < Illuminated Zone: 0dB(A) for δ > 0.88 + 2.14 log10
(10-3 + δ)dB(A) for0≤ δ <0.4m |
|
|
Reflection Effect |
Standard +1.5dB(A)
adopted. ·
No extra correction when the far-side barrier is not
vertical and the slope is greater than 15º, or if the height of far-side
barrier is less than ·
Absorptive Panel will be applied for proposed noise barrier,
reflective effect from those structure is negligible |
|
|
Speed Effect |
+20 log10
(V/130), where V = Train Speed |
|
|
Angle of View
Effect |
+10 log10 (pθ/180 – cos2
α sinθ) -5 , where θ= Angle of View
and α= Acute angle
between a line drawn through the NSR, parallel to the track, and the line
bisecting the angle of view, θ |
|
|
Façade Effect |
+2.5dB(A) [b] |
|
|
Track Wear
Correction |
+3.0dB(A) [b] |
|
|
Joint/Turnout
Correction |
As a very
conservative assumption, +7.0dB(A) for a representative |
|
|
Slab Track
Correction |
+2.5dB(A) |
|
|
Train Frequency |
30/24 trains per
hour in each direction during daytime/nighttime |
|
|
Train Frequency per
24hrs both directions |
850 trains |
|
|
Train Speed at the
open-track section |
60 - 80 kph near portal1A |
|
|
Noise Criteria |
ANL |
|
Note:
[a] Measurement data obtained from previous
measurement from West Rail “Wayside Noise Levels for the SP1900 EMU Operating
on West Rail Ballast and Sleeper Track”
[b] Refer to “Section
6.41
Noise
levels in Leq(30mins), Leq(24 Hours) and Lmax
were predicted at representative floor levels and the noise impact has been
quantified by exceedance of the criteria.
6.42
Mitigation
measures, in terms of provision of noise barrier would be proposed where
appropriated.
Fixed Plant Noise during Operational Phase (Ventilation Shafts)
6.43
It is
anticipated that noise specification of the proposed fixed plant may not be
available during the EIA Study, the maximum permissible noise emission levels
has been therefore determined for future detailed design of the fixed plant.
Cumulative impact from both the SCL (HUH-ADM), the SCL (TAW-HUH) and the KTE have been considered if there
is any plant located within
6.44
For the
assessment of noise from the fixed plant, the maximum permissible sound power
levels (Max. SWLs) of the identified fixed noise sources have been determined
by adopting standard acoustics principles.
The following formula has been used for calculating the Max. SWLs of the
fixed plant
SPL = Max SWL –
DC + FC - BC
Where
|
SPL |
Sound Pressure Level, in dB(A) |
|
Max. SWL |
Maximum Permissible Sound Power
Level, in dB(A) |
|
DC |
Distance Attenuation, in dB(A) (i.e 20 log D + 8 [where D is the distance in metres]) |
|
FC |
Facade Correction, in dB(A) (i.e. 3 dB(A)) |
|
BC |
Barrier Correction, in dB(A) |
6.45
It was
assumed that all the fixed plant within the same location would be operated at the
same time as worst case scenario. Screening correction offered by buildings or
other structures such as office and residential buildings has been taken into
account in calculating the predicted noise levels. According to the GW-TM, effective barriers can
result in noise reduction of 5 to 10dB(A) for the fixed plant depending on the
line of sight of the representative NSRs.
A positive 3 dB(A) has been added to predicted noise levels at the NSRs
due to the façade effect.
6.46
Corrections
of tonality, intermittency or impulsiveness have not been included owing to the
lack of design/supplier information at this detailed design stage. If the noise exhibits any of these
characteristics during detailed design or operation of the plant, the noise limit
of the plants should be reduced in accordance with the recommendation given in
IND-TM.
Airborne
Noise Impact Assessment
Construction Noise
during Non-restricted Hours
6.47
The plant inventory for the
assessment was confirmed by the Project Proponent that it is practicable for
the proposed works and listed in Appendix 6.2A. To strike a balance between the need for
providing a railway system to the public and the public concerns on the adverse
impacts, the following key features have been considered during the design of
the Project to alleviate the construction noise impacts as far as practicable:
Ÿ Minimisation of number of PME; and
Ÿ PME adopted for the same construction activities
would be grouped, where practicable, in order to reduce the construction noise
emission due to concurrent use of PME.
6.48
The unmitigated noise levels at
representative NSRs during non-restricted hours were predicted and presented in
Table 6.14 based
on construction programme and plant inventory as shown in Appendices 6.1A and 6.2A respectively.
Locations of notional sources and distance to NSRs are shown in Appendix
6.3A. A section illustrating the topography screening effect between
the construction site and
6.49
The sample calculation of
unmitigated construction noise levels during non-restricted hours for the most
affected NSR and the results according to the construction programme are
presented in Appendix 6.5A and 6.6A respectively.
Table 6.14 Unmitigated Construction Noise Levels
due to the Project
|
NSR ID |
Description |
Predicted Unmitigated Construction
Noise Levels, dB(A) |
EIAO-TM Noise
Criteria, dB(A) |
|
OM1 |
Shun Man House, Oi Man Estate |
52 - 83 |
75 |
|
OM2 |
Parc Palais, Block 6 |
50 - 76 |
75 |
|
OM3 |
Parc Palais, Block 1 |
48 - 69 |
75 |
|
OM4a(a) |
(All rooms are air-conditioned
and soundproof) |
52 – 76 (60 – 76)(c) |
65/70(b) |
|
HH1 |
|
51 - 78 |
75 |
|
HH2 |
|
63 - 84 |
75 |
|
HH4 |
|
58 - 79 |
75 |
|
HH7 |
The Metropolis Residence,
Tower 2 |
50 - 77 |
75 |
|
HH9 |
Harbourfront Horizon |
73 - 82 |
75 |
Note:
(a) For
OM4a, topography
screening effect has been included in calculation
(b) EIAO-TM
noise limits of Leq(30min) 70
dB(A) for schools during normal hours, 65 dB(A) during examination periods.
(c) Range
in parenthesis signifies predicted noise level during examination
periods which are assumed to be March, April, May and December of every year.
(d) Numbers in bold signify exceedances of the noise criteria.
6.50
The predicted noise levels at the
representative NSRs would range from 48 to 84 dB(A). Exceedances
in the range of 1 to 9 dB(A) were predicted at some NSRs. Mitigation measures will be required to abate
the construction noise impacts.
Construction Noise
during Restricted Hours
6.51
According to the construction
programme, most of the proposed construction works will be carried out during
non-restricted hours. Nonetheless, owing to the safety reason for works
adjoining the existing East Rail Line, construction works can only be
undertaken after the railway traffic hour (2300 to 0700hr). These activities will
be under the control of the NCO and the contractors are required to apply for a
CNP from the Noise Control Authority before works commence. An indicative
assessment has been undertaken to determine the impacts.
6.52
As discussed in Section 6.7, the
construction criteria of 55 dB(A) has been adopted at restricted hour (2300 to
0700hr) for the operation of PMEs.
6.53
The unmitigated noise levels at
representative NSRs during restricted hours was predicted and presented in Table 6.15 based
on construction programme as shown in Appendix 6.1B; and plant inventory as
shown in Appendix
6.2B. Locations of notional sources and distance to NSRs are shown in Appendix
6.3B. The works areas locations of the works during restricted hour are presented in Appendix
6.4B.
6.54
The sample calculation of
unmitigated construction noise levels during restricted hours for the affected NSRs
according to the construction programme are presented in Appendix 6.5B and the summary
of the assessment results are presented in Appendix 6.6B.
Table 6.15 Unmitigated Construction Noise Levels
during Restricted Hour
|
NSR ID |
Description |
Predicted Unmitigated Construction
Noise Levels, dB(A) |
NCO Noise
Criteria, dB(A) |
|
OM1 |
Shun Man House, Oi Man Estate |
75 |
55 |
|
OM2 |
Parc Palais, Block 6 |
72 |
55 |
|
OM3 |
Parc Palais, Block 1 |
63 |
55 |
|
HH1 |
|
64 |
55 |
Note:
(a) Numbers in bold signify exceedances
of the noise criteria.
6.55
The predicted noise levels at the
representative NSRs would range from 63 to 75 dB(A). Exceedances
in the range of 8 to 20 dB(A) were predicted at some NSRs. Mitigation measures
will be required to abate the construction noise impacts.
Operational Phase – Rail
Noise
6.56
The predicted air-borne rail
noise results from the Project are presented in Table 6.16. The segment distribution for
rail noise calculation is shown in Appendix 6.7, and sample calculation for unmitigated scenario is shown in Appendix
6.8. Exceedances
were predicted at representative NSRs OM
Table 6.16 Airborne
Rail Noise Calculation Summary – Unmitigated
|
|
|
Noise Criteria,
dB(A) |
|
Leq, 30min, dB(A) |
||
|
NSR |
Area Sensitivity Rating |
Daytime /evening |
Night-time |
Floor |
0700-2300 hrs |
2300-0700 hrs |
|
Shun Man House |
C |
70 |
60 |
2 |
51 |
49 |
|
South Block (OM |
|
|
|
7 |
64 |
62 |
|
|
|
|
|
12 |
65 |
64 |
|
|
|
|
|
17 |
64 |
63 |
|
|
|
|
|
23 |
63 |
62 |
|
Shun Man House |
C |
70 |
60 |
2 |
49 |
48 |
|
North Block (OM1b) |
|
|
|
7 |
62 |
61 |
|
|
|
|
|
12 |
64 |
63 |
|
|
|
|
|
17 |
63 |
62 |
|
|
|
|
|
23 |
62 |
61 |
|
Parc Palais, Block 6 |
C |
70 |
60 |
2 |
52 |
51 |
|
(OM2) |
|
|
|
7 |
55 |
54 |
|
|
|
|
|
12 |
54 |
54 |
|
|
|
|
|
17 |
54 |
53 |
|
|
|
|
|
24 |
53 |
52 |
|
|
C |
70 |
- |
2 |
52 |
- |
|
|
|
|
5 |
57 |
- |
|
|
|
C |
70 |
60 |
2 |
51 |
50 |
|
(HH1) |
|
|
|
7 |
51 |
50 |
|
|
|
|
|
12 |
51 |
50 |
|
|
|
|
|
17 |
51 |
50 |
|
|
|
|
|
20 |
52 |
51 |
|
|
C |
70 |
60 |
2 |
36 |
35 |
|
(HH2) |
|
|
|
8 |
36 |
35 |
Note:
[a]
[b] Numbers in bold signify exceedances of the noise criteria.
Operational Phase – Fixed Plant Noise
6.57
Locations
of fixed plant noise sources and NSRs are shown in Figure No. NEX2213/C/361/ENS/M52/601.
6.58
Most of the
premises around the HUH are non-noise sensitive developments in terms of
fixed source noise aspect, including hotels and service apartment. The nearest
Assessment Point/NSR is the Metropolis
Residence (HH7). Based on the backward calculation findings,
the maximum sound power levels are detailed in Table 6.17 for HUH and Table 6.18 for NOV. Details calculation for Daytime is shown in Appendix 6.9 whereas night-time calculation is shown in Appendix 6.10.
Table 6.17 Fixed Plant Noise Design Criteria for
HUH
|
Time Period |
Predicted Maximum
Sound Power Level, dB(A)
[a] |
|
|
Each Exhaust/Intake
Point at the Ventilation Shafts [b] |
Cooling Tower [b] |
|
|
Day and Evening (0700 to 2300
hours) |
Group 1: 104 Group 2: 99 |
Group 3: 101 Group 4: 104 |
|
Night (2300 to 0700 hours) |
Group 1: 92 Group 2: 88 |
Group 3: 88 Group 4: 94 |
Remark:
[a] If the noise exhibits any tonality,
intermittency or impulsiveness characteristics during the operation of the
plant, the noise design limit should be reduced to absorb these corrections in
accordance with the recommendation given in IND-TM
[b] Based on the preliminary engineering
information, the louver arrangements are:
² Group 1 - VS1
(1 louver at E direction); VS2 (1 louver at N direction); VS3 (1 louver at N
direction); VS4 (1 louver at N direction); VS5 (1 louver at N direction); VS6
(1 louver at N direction); VS7 (1 louver at N direction) - Assuming a total of
7 louvers, each with the same Group 1 SWL (each louver as a point source)
² Group 2 - VS8(1
louver at S direction); VS9 (1 louver at S direction); VS10 (1 louvers at S
direction); VS11 (1 louvers at S direction); VS12(1 louver at S direction);
VS13(1 louver at S direction); VS14(1 louver at S direction); VS15(1 louver at
S direction) - Assuming a total of 8 louvers, each with the same Group 2 SWL
(each louver as a point source)
² Cooling Tower Group 3 - (1 louver at N direction; 1 louver
at E direction) - Assuming a total of 2 louvers, each will be represented as a
point source with the same Group 3 SWL
² Cooling
Tower Group 4 - 5 louvers at top, assuming
each lourver will be represented as a point source
with the same Group 4 SWL
Table 6.18 Fixed Plant Noise Design Criteria for
NOV
|
Time Period |
Predicted Maximum
Sound Power Level, dB(A)
[a] |
|
Each
Exhaust/Intake Point at the |
|
|
Day and Evening (0700 to 2300
hours) |
100 |
|
Night (2300 to 0700 hours) |
90 |
Remark:
[a] If
the noise exhibits any tonality, intermittency or impulsiveness characteristics
during the operation of the plant, the noise design limit should be reduced to
absorb these corrections in accordance with the recommendation given in IND-TM
[b] Based on the preliminary engineering
information, the louver arrangements are:
²
2 louvers
at the Top
²
Assuming a
total of 2 louvers each with the same SWL (each louver as a point source)
6.59
If there is any change in engineering design information
during detailed design stage or fitting-out stage, the fixed source noise
design should be reviewed by engineer/contractor ensuring that both the NCO and
EIAO-TM criteria at NSR can be met in the future.
Recommended Mitigation
Measures
Air-borne Noise during Construction Phase
6.60
The construction noise assessment indicated that, in the
absence of any mitigation measures, there would be exceedance
of the construction noise criteria at some of the NSRs. Various mitigation options have thus been
considered in accordance with the guidelines laid down in the Environmental
Impact Assessment Ordinance, Guidance Note No. 9/2004 “Preparation of
Construction Noise Impact Assessment under the Environmental Impact Assessment
Ordinance” (GN 9/2004). It should be
noted that the assumptions used in formulating mitigation measures and their
practicality were based on the best available information from the detailed
design stage of the Project. Alternative mitigation proposals which could
achieve the same noise reduction effect may be formulated by the contractor
before construction. Mitigation measures considered are discussed below.
Good Site Practice
6.61
Although the noise mitigation effects are not easily
quantifiable and the benefits may vary with site conditions and operating
conditions, good site practices are easy to implement and do not impact upon
the works schedule. The site practices
listed below should be followed during each phase of construction:
Ÿ Only well-maintained plant should be operated
on-site and plant should be serviced regularly during the construction program
Ÿ Silencers or mufflers on construction equipment
should be utilized and should be properly maintained during the construction
program
Ÿ Mobile plant, if any, should be sited as far
from NSRs as possible
Ÿ Machines and plant (such as trucks) that may be
in intermittent use should be shut down between work periods or should be
throttled down to a minimum
Ÿ 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
Ÿ Material stockpiles and other structures should
be effectively utilized, wherever practicable, in screening noise from on-site
construction activities.
Adoption of Quiet
PME
6.62
In order to reduce the excessive noise impacts at the
affected NSRs during non-restricted hours, quieter PME are recommended. The Contractors may use other types of quiet
plant instead of specific items of quiet plant adopted in this assessment,
which have the same total SWL, to meet their needs. Quiet PME adopted in the assessment were
taken from the BS5228: Part 1:2009. It should be noted that the selected quiet
PME for assessment could be found in
6.63
A list of quiet PME recommended for adoption during the
construction phase is presented in Table 6.19.
Table 6.19 Quiet PME Recommended for
Adoption during Construction Phase
|
PME |
Reference |
SWL, dB(A) |
|
Asphalt Paver |
BS D8/24 |
101 |
|
Backhoe |
BS D3/35 |
106 |
|
Backhoe with
Hydraulic Breaker |
BS D8/13 |
110 |
|
Concrete Lorry
mixer |
BS D6/33 |
96 |
|
Concrete mixer
truck |
BS D6/33 |
96 |
|
Concrete Pump |
BS D6/36 |
106 |
|
Concrete
Pump Truck |
BS D6/36 |
106 |
|
Crane, mobile |
BS D7/101 |
94 |
|
Crawler crane |
BS D7/112 |
102 |
|
Drill, hand-held # |
CNP 065 |
98 |
|
Dump truck |
BS D9/24 |
104 |
|
Excavator |
BS D3/35 |
106 |
|
Flat Bed Lorry |
BS D9/19 |
102 |
|
Generator |
CNP 103 |
95 |
|
Giken Piler and Power-pack |
EIA Ref. |
94 |
|
Hydraulic
breaker |
BS D8/13 |
110 |
|
Hydraulic
Excavator |
BS D3/35 |
106 |
|
Lorry |
BS D9/19 |
102 |
|
Lorry with crane/grab |
BS D7/101 |
94 |
|
Mini Piling Rig |
BS D11/2 |
112 |
|
Piling Rig |
BS D11/2 |
112 |
|
Poker,
vibrator, hand-held |
BS D6/40 |
98 |
|
Road Roller |
BS D8/30 |
101 |
|
Rock Drill |
EIA Ref. |
108 |
|
Roller |
BS D8/30 |
101 |
|
Truck |
BS D9/39 |
103 |
|
Vibratory Hammer |
BS D4/53 |
118 |
Note:
#: Applied
for the works during restricted hours only.
EIA Ref.: The
SWL of Giken Piler and
Power-pack & Rock Drill were made
reference to the approved EIA Report of “Tsim Sha Tsui Station Northern Subway”
Use of Movable
Noise Barrier
6.64
The use of movable barrier for certain PME could further
alleviate the construction noise impacts.
In general, 5dB(A) reduction for movable PME and 10dB(A) for stationary
PME can be achieved depending on the actual design of movable noise barrier.
Typical arrangements of the moveable noise barriers for sample NSRs are shown
in Appendix
6.11C.
6.65
Table
6.20 shows the assumed
noise reduction effects achieved by the movable noise barrier for certain items
of PME. The Contractor shall be
responsible for design of the movable noise barrier with due consideration
given to the size of the PME and the requirement of intercepting the line of
sight between the NSRs and PME. Barrier
material of surface mass in excess of 14 kg/m2 is recommended to
achieve the predicted screening effect.
Use
of Noise Insulating Fabric
6.66
Noise insulating fabric (the Fabric) would be adopted for
certain PME (e.g. drill rig, piling rig etc). The Fabric should be lapped such
that there would be no openings or gaps on the joints. With reference to MTRC
Contract C4420 Tsim Sha
Tsui Modification Noise Assessment Report for Variation of Environmental Permit
(July 2003) and the technical data from manufacturer, a noise reduction of over
10 dB(A) could be achieved with the use of the Fabric. As a conservative
approach, a noise reduction of 10 dB(A) for the PME lapped with the Fabric was
assumed in this assessment.
Use of Noise
Enclosure/Acoustic Shed
6.67
Noise enclosure would be used to cover stationary PME such
as air compressors and generator. With the adoption of the noise enclosure, the
PME could be completely screened, and noise reduction of 15 dB(A) could be
achieved with reference to Paragraph 4.5 of EIAO Guidance Note No. 9/2004. Schematic configurations of typical noise enclosure and movable barrier
are depicted in Appendix 6.11D.
Temporary hoardings
6.68
Temporary
hoardings of 2.4m high are recommended for identified NSRs which are located
near to the works area. PMEs involved in
construction would be or partly screened by the erected site hoardings.
Summary of direct
mitigation measures
6.69
A summary
of the
assumed noise reduction effects achieved by the use
of movable
noise barrier for certain item of PME is
presented in Table
6.20.
Table 6.20 Noise Mitigation Measures for
Certain PME during Construction Phase
|
PME |
Mitigation Measures Proposed |
Noise Reduction, dB(A) |
|
Air compressor |
Enclosure/ Shed |
15 |
|
Asphalt paver |
Movable Barrier |
5 |
|
Backhoe |
Movable Barrier |
5 |
|
Backhoe with Hydraulic Breaker |
Movable Barrier |
5 |
|
Bar Bender and Cutter |
Movable Barrier |
10 |
|
Crane, mobile |
Movable Barrier |
5 |
|
Concrete Pump |
Movable Barrier |
10
|
|
Drill Rig |
Fabric |
10 |
|
Drill, hand-held |
Movable Barrier |
5 |
|
Excavator |
Movable Barrier |
5 |
|
Generator |
Movable Barrier |
10
|
|
Generator # |
Enclosure/ Shed |
15 |
|
Grout Pump |
Movable Barrier |
10
|
|
Hand held Breaker |
Movable Barrier |
5 |
|
Hydraulic Breaker |
Movable Barrier |
5 |
|
Hydraulic Excavator |
Movable Barrier |
5 |
|
Lorry with crane/grab |
Movable Barrier |
5 |
|
Mini Piling
Rig |
Fabric |
10 |
|
Piling Rig |
Fabric |
10 |
|
Piling, diaphragm wall, bentonite
filtering plant |
Fabric |
10 |
|
Piling, large diameter bored, grab and chisel |
Fabric |
10 |
|
Saw, concrete |
Movable Barrier |
10 |
|
Vibratory Hammer |
Fabric |
10 |
Note:
#: Applied
for the works during restricted hours only.
Construction Works
next to School
6.70
The daytime
construction noise criterion during school examination period is 65 dB(A),
which is lower than the normal daytime school criterion of 70 dB(A).
6.71
As
Mitigated
Construction Noise Impacts
Construction
Phase during Non-restricted Hours
6.72
With the
implementation of all the above-mentioned mitigation measures, the total SWLs
of each activity were predicted and presented in Appendix 6.11A. Detailed calculation of the most affected NSR is
given in Appendix 6.12A for
reference. Whereas predicted construction
noise level according to working schedule is summarized in Appendix 6.13A and ranges of noise level are shown in Table 6.21. The predicted noise levels due to the Project itself at all NSRs are ranged from 32 -73 dB(A)
and comply with the EIAO-TM noise criteria.
6.73
In terms of
the cumulative impacts with SCL (HUH-ADM), SCL (TAW-HUH) and KTE, the predicted noise levels are also
presented in Table
6.21. Exceedance of 1 to
3 dB(A) would be expected at Wing Fung Building (HH2); while exceedance of 1 to 4 dB(A) during examination period would
be expected at
Table 6.21 Cumulative
Construction Noise Levels during Construction Period – Mitigated
|
|
EIAO-TM
Noise Criteria, dB(A) |
Predicted Noise Levels arising from, dB(A), Leq(30mins) |
Cumulative Noise Level, dB(A) |
|||
|
NSR ID |
The Project |
SCL (HUH-ADM) |
SCL (TAW-HUH) |
KTE (with KTE’s EPIWs) |
||
|
OM1 |
75 |
36 - 71 |
- |
- |
- |
36 - 71 |
|
OM2 |
75 |
34 - 63 |
- |
- |
53 |
34 - 63 |
|
OM3 |
75 |
32 - 56 |
- |
- |
48 - 62 |
48 - 62 |
|
OM4a [a] |
65/70[b] |
36 - 65 (48 - 65) (c) |
- |
- |
56 - 69 (56 – 67) (c) |
53 - 70 (53 - 69) (c) |
|
HH1 |
75 |
35 - 64 |
- |
- |
- |
35 - 64 |
|
HH2 |
75 |
49 - 73 |
- |
51 - 77 |
58 -
67 |
55 - 78 |
|
HH4 |
75 |
55 - 73 |
- |
55 - 57 |
- |
55 - 73 |
|
HH7 |
75 |
47 - 73 |
- |
54 - 55 |
- |
50 - 73 |
|
HH9 |
75 |
64 - 73 |
62 –
71 |
50 - 54 |
57 |
64 - 74 |
Note:
[a] For OM4a, topography screening effect has been included in calculation.
[b] EIAO-TM noise limits of Leq(30min) 70 dB(A) for schools
during normal hours, 65 dB(A) during examination periods.
[c] Range
in parenthesis signifies predicted noise level during examination
periods which are assumed to be March, April, May and December of every year.
[d] Numbers in bold signify exceedances of the noise criteria.
Construction
Phase during Restricted Hours
6.74
With the adoption of the recommended mitigation measures, as shown in Appendix 6.11B, including reduction
of plant, use of enclosure/barrier and regrouping of PME works, detailed
calculation of the affected NSRs is given in Appendix 6.12B. Whereas, the predicted construction
noise levels according to working schedule are summarized in Appendix
6.13B, and ranges of noise level are shown in Table 6.22.
6.75
The predicted noise levels at all
NSRs would comply with the construction noise criterion during restricted
hours.
Table 6.22 Mitigated Construction Noise Levels
during Restricted Hour
|
NSR ID |
Description |
Predicted Mitigated Construction Noise Levels,
dB(A) |
NCO Noise
Criteria, dB(A) |
|
PME Works under GW-TM |
|||
|
OM1 |
Shun Man House, Oi Man Estate |
55 |
55 |
|
OM2 |
Parc Palais, Block 6 |
51 |
55 |
|
OM3 |
Parc Palais, Block 1 |
43 |
55 |
|
HH1 [a] |
|
44 |
55 |
Evaluation of Residual
Impacts
Construction Phase
during Non-restricted Hours
6.76
As shown in Table
6.21, the residual noise impacts at OM4a are mostly in the range of 1-4dB(A) during examination period. As OM4a has already been noise insulated with
air-conditioners that a noise attenuation of 10 dB(A) could be achieved, it is
considered that the noise impact would be minimised by keeping the windows
closed during the construction activities.
Notwithstanding this, it is recommended that particularly noisy
construction activities especially for diversion works of Oi
Sen Path (Site ID. No. OSPPS in Appendix 6.3A), should be scheduled to
avoid examination periods as far as practicable to minimise residual impact.
6.77
Impact of 1 to 3 dB(A) would be expected at Wing Fung Building (HH2) when
considering cumulative construction noise impacts with concurrent work of SCL
(TAW-HUH) and KTE. With reference to the
SCL (TAW-HUH) EIA Report, quiet PMEs, temporary movable noise barriers and
enclosures have already been proposed to alleviate the noise impact. Residual impact to HH2 would mainly due to
its limited separation between HH2 and construction site (~
6.78
The magnitude of the residual impacts has been assessed in accordance
with Section 4.4.3 of the EIAO-TM in Table 6.23 below.
Table 6.23 Assessment
of Residual Impacts from Construction Noise
|
Criteria |
Assessment |
|
|
Effects on public health and health of biota or risk to
life |
The extent of noise nuisance would be unlikely to induce
public health concern |
|
|
Magnitude of the adverse environmental impacts. |
Residual impacts of between 1-3dB(A)
could occur at up to 100 flats;
and 1-4dB(A)
at 1 school for examination period during the
construction phase based upon worse case scenarios. |
|
|
Geographic extent of the adverse environmental impacts. |
The geographic extent of the adverse impacts from noise
will not be large and is anticipated to be limited to within about 10m from
the Project works area. |
|
|
Duration and frequency of the adverse environmental
impacts |
The construction noise impacts of the Project will be from
1 to 8 months for the
affected residential premises; and 1 to 5 months for the affected school
(noise insulated with air conditioners), and are, therefore, temporary and reversible. |
|
|
Likely size of the community or the environment that may
be affected by the adverse impacts |
Minimal
size of the community would be affected, and therefore
be considered acceptable. |
|
|
Degree to which the adverse environmental impacts are
reversible or irreversible. |
Construction phase impacts should be reversible. |
|
|
Ecological context. |
Not Applicable |
|
|
Degree of disruption to sites of cultural heritage. |
Not Applicable |
|
|
International and regional importance. |
The impacts are localised and not of international and
regional importance. |
|
|
Likelihood and degree of uncertainty of adverse
environmental impacts. |
The impacts predicted are based upon worst case assumptions
and as such, would not occur to the extent predicted on all occasions. However, the assessment has been made using
approved mathematical modelling techniques and the degree of certainty on the
results is high. |
6.79
Based upon the above, the following factors should be considered in
determining the residual impacts:
Ÿ The noise impacts are not predicted to
significantly affect their health or cause loss of life;
Ÿ The predicted impacts are temporary and
reversible;
Ÿ Impacts are localised and not of international
and regional importance;
Ÿ The geographic extent of the adverse impacts is
confined to small works areas around the trunk road
Ÿ The mitigation measures proposed will reduce the
levels of impacts; and
Ÿ The study area has not shown itself to be
fragile or undisturbed.
6.80
The MTR Corporation will facilitate communications with the concerned
parties with cumulative residual impacts during construction and review to
consider other initiatives, such as construction phasing, if required.
6.81
As such, the residual impacts associated with the construction phase
would be considered minor and acceptable.
Operational Phase – Rail
Noise
6.82
In order to
minimise the noise impact, mitigation measures have been proposed and depicted
in the Appendix
6.14. Proposed mitigation
measures near Portal 1A will only be required after SCL (MKK-HUH) comes into operation when the existing East Rail
Line is diverted to the SCL tracks. Details are summarized as below:
Ÿ 150m
long natural ventilated absorptive noise enclosure extending from portal 1A,
typical section is shown in Appendix 6.14.
6.83
The
proposed mitigation measure for rail noise may be revised subject to compliance
of fire services requirements. Fire Service Department (FSD)’s requirement of
45% opening on top of the proposed noise enclosure for natural ventilation
provision has been incorporated in the design. In addition, the top will be
offset by 3m down to allow smoke to pass through. In order to reduce the line
of sight to the nearby sensitive receivers, an overlapping of 500mm between the
opening will be in place.
6.84
The
predicted airborne rail noise results for mitigated scenario from the Project
are presented in Table
6.24 and detailed in Appendix
6.15. The results show that the
predicted noise levels, in terms of Leq, 30mins,
Leq, 24hrs and Lmax,
at all NSRs would comply with the noise criteria after the implementation of
the above-mentioned mitigation measures.
Table 6.24 Airborne
Rail Noise Calculation Summary – Mitigated
|
|
|
Criteria, dB(A) |
|
Leq, 30min, dB(A) |
||
|
NSR |
Area Sensitivity Rating |
Daytime /evening |
Night-time |
Floor |
0700-2300 hrs |
2300-0700 hrs |
|
Shun Man House |
C |
70 |
60 |
2 |
50 |
49 |
|
South Block (OM |
|
|
|
7 |
49 |
48 |
|
|
|
|
|
12 |
48 |
47 |
|
|
|
|
|
17 |
48 |
47 |
|
|
|
|
|
23 |
48 |
46 |
|
Shun Man House |
C |
70 |
60 |
2 |
49 |
47 |
|
North Block (OM1b) |
|
|
|
7 |
48 |
47 |
|
|
|
|
|
12 |
47 |
46 |
|
|
|
|
|
17 |
47 |
45 |
|
|
|
|
|
23 |
46 |
45 |
|
Parc Palais, Block 6 |
C |
70 |
60 |
2 |
40 |
39 |
|
(OM2) |
|
|
|
7 |
40 |
39 |
|
|
|
|
|
12 |
40 |
39 |
|
|
|
|
|
17 |
40 |
39 |
|
|
|
|
|
24 |
40 |
38 |
|
|
C |
70 |
- |
2 |
47 |
- |
|
|
|
|
5 |
47 |
- |
|
|
|
C |
70 |
60 |
2 |
51 |
50 |
|
(HH1) |
|
|
|
7 |
51 |
50 |
|
|
|
|
|
12 |
51 |
50 |
|
|
|
|
|
17 |
51 |
50 |
|
|
|
|
|
20 |
51 |
50 |
|
|
C |
70 |
60 |
2 |
36 |
35 |
|
(HH2) |
|
|
|
8 |
36 |
35 |
Note:
[a]
Cumulative impact
6.85
The Project
will interface with SCL (TAW-HUH) and KTE in Hung Hom
and Ho Man Tin, Nonetheless,
the interfacing rail segments for SCL (TAW-HUH) and KTE are either underground
or shielded by existing buildings. No
contribution from these two concurrent projects is anticipated as shown in Table 6.25.
Table 6.25 Cumulative
Airborne Rail Noise Summary – Mitigated
|
|
Criteria dB(A) |
Predicted Noise Levels arising from, dB(A), Leq(30mins) |
Cumulative Noise Level, dB(A) |
||||
|
NSR ID |
The Project |
SCL (TAW-HUH) [a] |
KTE [c] |
||||
|
Daytime/evening |
|
|
|
|
|
||
|
OM |
70 |
48-50 |
- [a] |
- |
48-50 |
||
|
OM1b |
46-49 |
- [a] |
- |
46-49 |
|||
|
OM2 |
40 |
- [a] |
- |
40 |
|||
|
OM4b |
47 |
- [a] |
- |
47 |
|||
|
HH1 |
51 |
- [a] |
- |
51 |
|||
|
HH2 |
36 |
42 [d]
|
- |
43 |
|||
|
Night-time |
|
|
|
|
|
||
|
OM |
60 |
46-49 |
- [a] |
- |
46-49 |
||
|
OM1b |
45-47 |
- [a] |
- |
45-47 |
|||
|
OM2 |
38-39 |
- [a] |
- |
38-39 |
|||
|
OM4b [b] |
- |
- |
- |
- |
- |
||
|
HH1 |
60 |
50 |
- [a] |
- |
50 |
||
|
HH2 |
35 |
39 [d] |
- |
40 |
|||
Notes:
[a] SCL (TAW-HUH) has open air railway tracks
confined between HUH and
[b]
[c] All tracks for
KTE will be underground, and thus there is no cumulative impact
[d] In SCL (TAW -
HUH) EIA Report, 24 trains/direction/hour is assumed for the noise
assessment. In addition, a sensitivity test has been conducted to examine the
noise effect if the train frequency is increased in the future operation. As
compared with the predicted daytime noise levels based on the assumption of 24
trains/direction/hour , an increase of 0.3 dB(A) and 0.7 dB(A) would be
predicted respectively for 26 and 28 trains/direction/hour . Hence,
the predicted noise levels of SCL (TAW - HUH) would still comply with the noise
criterion even if 26 and 28 trains/direction/hour during day time periods
are adopted.
6.86
Considering
the cumulative contribution from the Project, SCL (TAW-HUH) and KTE, the
predicted noise levels at all NSRs are more than 10dB(A) below the noise
criteria. Adverse impact from the Project is not anticipated.
6.87
In terms of
the East Rail Line operation, with the extra noise attenuation effect from the
SCL noise mitigation measures at Portal 1A, the noise contribution from the
infrequent intercity and maintenance trains could be lower as compared to the
existing condition. With the 10dB(A) margin below the noise criteria, adverse
impact from the Project is therefore not anticipated.
Operational Phase – Fixed Plant Noise
6.88
The fixed
plant properly designed to meet the maximum SWL listed in Tables 6.17 and 6.18, there
would not be any adverse residual impacts predicted. However, it is still recommended that the
following noise reduction measures be considered as far as practicable during
the processes of detailed design and procurement:
Ÿ Choose quieter plant such as those which have
been effectively silenced.
Ÿ Include noise levels specification when ordering
new plant (including chillier and E/M equipment).
Ÿ Locate fixed plant/louver away from any NSRs as
far as practicable.
Ÿ Locate fixed plant in walled plant rooms or in
specially designed enclosures.
Ÿ Locate noisy machines in a basement or a completely
separate building.
Ÿ Install direct noise mitigation measures
including silencers, acoustic louvers and acoustic enclosure where necessary.
Ÿ Develop and implement a regularly scheduled
plant maintenance programme so that equipment is properly operated and serviced
in order to maintain controlled level of noise.
The programme should be implemented by properly trained personnel.
Environmental Monitoring and
Audit Requirements
6.89
An Environmental Monitoring and Audit programme is recommended
to be established according to the predicted occurrence of noisy activities.
The recommended mitigation measures should be implemented during construction
stage. Details of the programme are
provided in a stand-alone EM&A Manual.
6.91
Noise
arising from the construction activities of the project would have unavoidable
potential impact on the NSRs located in the vicinity of the works areas. Unmitigated construction noise levels at the
representative NSRs are predicted, which are found to be in the range of 48 to 83 dB(A) for the works during
non-restricted hours; and in the range of 63 to 75 dB(A) for the works during restricted hours.
6.92
With
respect to the Project contribution alone, mitigation measures have been
recommended to reduce the noise levels to within the EIAO-TM noise criterion,
including good site practices, quieter plant, movable noise barrier and noise
insulating fabric. With these measures in place, predicted
construction noise levels due to the Project at all NSRs comply with the
EIAO-TM daytime construction noise criterion.
6.93
With
respect to the cumulative impact, mitigated cumulative construction noise levels
at the representative NSRs were predicted ranging from 34 to 78 dB(A). Residual cumulative noise impact of 1 to 4 dB(A)
for a short duration of non-persistent 5 months was found at Carmel Secondary School (OM4a) during examination period;
and 1-3dB(A) exceedance is anticipated for non-persistent 8 months was found
at Wing Fung Building (HH2).
6.94
As OM4a has been noise insulated with air conditioners
and, by keeping the windows closed during construction activities, noise
impacts at the indoor environment can be alleviated. Notwithstanding this, it is recommended that
the particularly noisy construction activities be scheduled to avoid
examination period as far as practicable.
6.95
Impact at
HH2 would be dominated by concurrent project SCL (TAW-HUH) and the Project due
to close distance to the construction site (~
6.96
Thus, the residual impacts are
concluded to be temporary, reversible and unlikely to induce public health
concern and as such, are considered to be minor and acceptable.
6.97
According to
the construction programme, most of the proposed construction works will be
carried out during non-restricted hours. Nonetheless, owing to the safety
reason for works adjoining the existing East Rail, a minor portion of
construction works can only be undertaken after the railway traffic hour (2300
to 0700hr). These activities will be under the control of the NCO and the
contractors are required to apply for a CNP from the Noise Control Authority
before works commence. An indicative assessment has been undertaken to
determine the impacts. With the consideration of quiet plant, movable
barrier/enclosure, regrouping of PME works and reduction of active plants, all NSRs would comply with the construction noise criterion.
Operational Phase – Rail
Noise
6.98
According to Table 6.16, under
unmitigated scenario, noise exceedance at night-time
would occur at Shun Man House North and South Blocks by up to 4dB(A). In order to
minimise the noise impact, natural ventilated noise enclosure and barriers are
proposed at Portal
6.99
Considering
the cumulative contribution from the Project, SCL (TAW-HUH) and KTE, the
predicted noise levels at all NSRs are more than 10dB(A) below the noise
criteria. Adverse impact from the Project is not anticipated.
6.100
In terms of
the East Rail Line operation, the freight train operation to cease before the
Project operation, and thus there will be no contribution from freight train.
Together with the extra noise attenuation effect from the SCL noise mitigation
measures at Portal 1A, the noise contribution from the infrequent intercity and
maintenance train could be lower as compared to the existing condition. With
the 10dB(A) margin below the noise criteria, adverse impact from the Project is
therefore not anticipated.
Operational Phase – Fixed
Plant Noise
6.101
The maximum
sound power levels allowed to be emitted from each louver of ventilation shafts were predicted as point sources. With the proper selection of plant and
adoption of acoustic treatment, the NSRs located in the vicinity of ventilation
buildings will not be affected by the noise from louvers.
6.102 If there is any change in engineering design
information during detailed design stage or fitting-out stage, the fixed source
noise design should be reviewed by engineer/contractor ensuring that both the
NCO and EIAO-TM criteria at NSR can be met in the future.