7.1.1.1
Potential construction air-borne noise impacts will
be generated from activities including excavation, cut-and-cover, tunnelling,
retaining wall construction, piling, backfilling, road reinstatement and
construction of above ground structures, which are anticipated to be in the
immediate vicinity of the noise sensitive receivers (NSRs) especially the
residential buildings in Whampoa and institutional uses in Yau Ma Tei. In addition, loading / unloading of
construction materials at the barging point at Hung Hom Finger Pier, will also be
potential sources of noise impact affecting NSRs nearby.
7.1.1.2
During the operation of railway systems, operational
air-borne noise impacts will be generated from the fixed plant noise sources
associated with the stations and ventilation shafts etc. All of these fixed plant noise sources (as
well as other similar noise sources) have been identified and assessed;
including potential cumulative impacts.
This has allowed the fixed plant noise levels (and maximum sound power
levels) to be determined and mitigated where necessary.
7.2.1.1
A description of the KTE project can be found in Section 3 of this EIA report with the layout of the proposed railway alignment,
stations, and the associated structures.
During the construction phase, air-borne noise issues may arise due to
the use of powered mechanical equipment (PME) for various works
activities including the establishment and reinstatement works with respect to the works
items listed in Table 3.1:
· YMT Station Interface (works site for Item 1A);
· Running Tunnels from YMT Station to HOM Station (works sites for Items 2A, 2C and 2D);
· HOM Station (works sites for Items 3A-3C, 3E-3G and 3I-3K);
· Running Tunnels from HOM Station to WHA Station (works sites for Item 4A);
· WHA Station (works sites for Items 5A-5E); and
· Hung Hom Finger Pier Barging Point (works areas for Item 6A).
7.2.1.2
Rock crushing facilities will also be in operation
during the construction phase. One rock
crushing facility would be located at the work site for HOM Station (Item 3A)
for a period of 19 months and two others would be located at the barging point
(Item 6A) for 29.5 months of the construction period. The rock crushing facilities are Designated
Projects under Schedule 2, Part 1, Section G.5 of the EIAO.
7.2.1.3
Construction noise may also arise from site
formation works at the temporary magazine site at TKO Area 137. There are no noise sensitive receivers within
300m of the temporary magazine, and therefore it is not included in the assessment.
7.2.1.4
During the operational phase, there would be no
air-borne railway noise impacts as the entire KTE alignment would be
underground. Only fixed plant noise
sources would arise from the tunnel ventilation building at Club de Recreio,
and ventilation shafts and station facilities at HOM Station and WHA Station.
7.3
Environmental Legislation, Standards and Guidelines
7.3.1
Background
7.3.1.1
The Noise Control Ordinance (NCO) and the EIAO
provide the statutory framework for noise control. Assessment procedures and standards are set
out in the technical memoranda (TM) given below.
· The TM on EIA process (EIAO-TM);
· The TM on Noise from Construction Work other than Percussive Piling; (GW-TM);
· The TM on Noise from Percussive Piling (PP-TM);
· The TM on Noise from Construction Work in Designated Areas; (DA- TM); and
· The TM for the Assessment of Noise from Places Other Than Domestic Premises, Public Places or Construction Sites (IND-TM).
7.3.1.2
Any noise from percussive piling is controlled by
the PP-TM and an application to EPD for a Construction Noise Permit (CNP) would
be required.
7.3.2
Construction
Phase
Noise Standards for Non-restricted Hours
7.3.2.1
Daytime construction noise excluding percussive
piling between the hours 0700 and 1900 on weekdays, i.e. non-restricted hours,
is controlled under the EIAO. Annex 5 of
the EIAO sets out the construction noise assessment limits, which are Leq(30
min) 75dB(A) for domestic premises and hotels, and Leq(30 min) 70dB(A) during
normal hours for educational institutions including kindergartens (65dB(A)
during examination periods), nurseries and all other places where unaided voice
communication is required. The
recommended noise standards are summarised in Table 7.1 below.
Table 7.1: Daytime
Construction Noise Limit
|
Uses |
Noise Standard (Leq, 30 min dB(A)) |
|
Domestic premises, hotels
and hostels |
75 |
|
Educational institutions,
kindergartens, nurseries and all others where voice communication is required |
70 (65
during examination period) |
Note: The
above criteria apply to noise sensitive uses which rely on open window for
ventilation and should be viewed as the maximum permissible noise levels
assessed at
Noise Standards for Restricted Hours
7.3.2.2
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 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 on the
Area Sensitivity Ratings (ASRs). The ASRs are determined
based on the best available information at this stage and are unlikely to be significantly
different at the time of project implementation unless there are substantial
changes such as building redevelopment or land use changes in the near vicinity
of the NSRs. However, nothing in this
report shall bind the Noise Control Authority in the context of law enforcement
against any noise sources being assessed.
The corresponding basic noise
levels (BNLs) for evening and night-time periods are given in Table
7.2.
Table 7.2: Construction Noise Criteria for Activity
other than Percussive Piling
|
Time Period |
Basic Noise Levels (BNLs), dB(A) |
||
|
ASR ‘A’ |
ASR ‘B’ |
ASR ‘C’ |
|
|
Evening (1900 to 2300 hrs)[a] |
60 (45) |
65 (50) |
70 (55) |
|
Night-time (2300 to 0700 hrs) |
45 (30) |
50 (35) |
55 (40) |
[a] Includes Sunday and Public Holidays during daytime
and evening.
Figures in brackets are
BNLs for Specified Powered Mechanical Equipment (SPME) construction work in designated areas.
7.3.2.3
As
noise in restricted periods is covered by the NCO, it is not assessed further
in this EIA under the EIAO and despite any reference made in this EIA Report on
construction noise aspects during restricted periods, 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 TM issued under the Noise Control
Ordinance. The Noise Control Authority
will take into account contemporary conditions/situation of adjoining land uses
and any previous complaints against construction activities at the site before
making his decision in granting a CNP.
Nothing in the 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 seen fit. Failure to comply with any such conditions
will lead to cancellation of the CNP and prosecution action under the NCO.
7.3.2.4
Under
the DA-TM, the use of five types of SPME and three types of Prescribed
Construction Work (PCW) within a designated area during restricted hours would
require a valid CNP. The SPME includes a
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; and
· Hammering.
7.3.2.5
In
general, it cannot be presumed that a CNP would be granted for carrying out PCW
within a designated area during restricted hours but it may be granted if the
relevant ANLs and criteria stipulated in the GW-TM and DA-TM can be met.
7.3.2.6
As
defined in the Noise Control Designated Area Plan, the whole KTE alignment and
works areas are within the Designated Area.
7.3.2.7
According
to the construction programme, all the proposed construction works will be
carried out during non-restricted hours. In case of any construction activities during
restricted hours, it is the Contractor’s responsibility to ensure compliance
with the NCO and the relevant TMs. The
Contractor will be required to submit a CNP application to the Noise Control
Authority and abide by any conditions stated in the CNP, should one be issued.
Blasting
7.3.2.8
While
air-borne (and ground-borne) noise due to blasting is not required to be
assessed, if it is unavoidable to undertake blasting during sensitive hours (1900
to 0700 from Monday to Saturday and any time on a public holiday, including
Sunday), then noise impacts associated with the removal of debris and rocks have
been assessed and mitigation measures recommended to reduce the impact as
required.
7.3.2.9
Notwithstanding,
the administrative and procedural control of all blasting operations in Hong
Kong is vested in the Mines Division of the Civil Engineering and Development
Department (CEDD). The Dangerous Goods
(General) Regulations also stipulates that no person shall carry out blasting
unless he possesses a valid mine blasting certificate to be issued by the Mines
Division of CEDD. The Superintendent of
Mines will review the application on a case-by-case basis before issuing the
Mine Blasting Certificate.
7.3.3
Operational
Phase
Fixed Sources
7.3.3.1
The
NCO and IND-TM control noise from fixed noise sources such as ventilation
shafts, chillers and cooling towers. For
the assessment of impacts from these fixed noise sources, the ASR of the NSRs
must be determined in accordance with the IND-TM, and then based on the ASR,
the appropriate ANL can be determined. The ASRs are determined
based on the best available information at this stage and are unlikely to be
significantly different at the time of project implementation unless there are
substantial changes such as building redevelopment or land use changes in the
near vicinity of the NSRs. However,
nothing in this report shall bind the Noise Control Authority in the context of
law enforcement against any fixed noise sources being assessed. The
ANL is shown in Table 7.3.
Table 7.3: Acceptable Noise Level for Fixed Plant Noise
|
Time Period |
NCO Criteria |
EIAO-TM |
||||
|
ASR ‘A’ |
ASR ‘B’ |
ASR ‘C’ |
ASR ‘A’ |
ASR ‘B’ |
ASR ‘C’ |
|
|
Daytime and Evening (0700-2300 hrs) |
60 |
65 |
70 |
55 |
60 |
65 |
|
Night-time (2300-0700 hrs) |
50 |
55 |
60 |
45 |
50 |
55 |
Source – IND-TM
7.3.3.2
It is
anticipated that, due to the urban nature of the KTE project, most of the study
areas will be significantly affected by traffic activities and as such an ASR
of ‘C’ will be mostly allocated.
However, in areas where a lesser traffic influence is anticipated, an
ASR of B would be allocated.
7.3.3.3
The
ASR is indicative only and the noise from the fixed sources is controlled under
Section 13 of the NCO. The prevailing
legislation, practices contemporary conditions and situation of adjoining land
use should all be considered in determining noise impact.
7.3.3.4
More
stringent criteria for assessing fixed plant are recommended in the EIAO-TM for
planning purposes. The recommended
assessment criteria are:
· Criteria (1): 5dB(A) below the appropriate ANL set out in the IND-TM; and
· Criteria (2): The prevailing background noise level where this is 5dB(A) below the appropriate ANL (i.e. ANL -5dB(A)).
7.3.3.5
Criteria
(2) would be more stringent than Criteria (1) and would generally apply to
areas with low ambient noise levels such as rural areas and suburban
areas. The Project areas are densely
populated areas strongly influenced by traffic and as noted from site
inspections, the prevailing noise levels are unlikely to be 5dB(A) lower than
the appropriate ANL. Thus Criteria 1 has
been adopted for this urban Study Area and this will be confirmed during the
assessment.
Air-borne Railway Noise
7.3.3.6
During the operational phase, there would be no
air-borne railway noise as the entire KTE alignment would be underground.
7.4.1.1
The
whole alignment is located within a densely populated urban area with
residential buildings and schools, and, therefore, there are a relatively large
number of NSRs in the vicinity of the KTE project area. The existing and future NSRs selected for both
construction and operation noise assessment are listed in Table
7.4 and illustrated
in Figures 7.1-7.9. Details of
the NSRs are presented in Appendix 7.1. For specific NSRs, more than one direction
will be evaluated. However, they will be
discussed collectively as a single NSR.
Table 7.4: Representative
Air-borne Noise Sensitive Receivers
|
Noise
Sensitive Receiver |
Construction |
Operation |
|
|
5 |
|
Y |
|
|
6 |
|
Y |
|
|
11 |
|
Y |
Y |
|
12 |
Primary School at |
Y |
Y |
|
13a |
Parc Palais Block 1 |
Y |
|
|
13b |
Parc Palais Block 3 |
Y |
|
|
13c |
Parc Palais Block 6 |
Y |
|
|
16 |
|
Y |
|
|
18-1 |
1/F, Yee Fu Building |
Y |
Y |
|
18-7 |
7/F, Yee Fu Building |
Y |
Y |
|
19 |
|
Y |
Y |
|
20 |
Caritas Bianchi |
Y |
Y |
|
21 |
Lok Ka House |
Y |
Y |
|
22 |
Lok Do Building |
Y |
|
|
23 |
|
Y |
|
|
27 |
Block Y, Ki Fu Building,
Whampoa Estate |
Y |
|
|
28 |
Block H, On |
Y |
Y |
|
29 |
Block 9, |
Y |
Y |
|
30 |
Block 1, |
Y |
|
|
31 |
Block 5, |
Y |
|
|
32 |
Block 13, |
Y |
Y |
|
33 |
Block 1, |
Y |
Y |
|
34 |
|
Y |
Y |
|
35 |
|
Y |
Y |
|
36 |
Harbourfront Landmark |
Y |
|
|
39 |
Harbourfront Horizon |
Y |
|
|
40 |
Residential Building, Ho
Man Tin Station Development (Planned Future NSR) |
|
Y |
|
41 |
Residential Building,
Dormitory for The |
|
Y |
|
44 |
|
Y |
|
|
45 |
|
|
Y |
|
46 |
Block Q, Ho |
|
Y |
|
47 |
Block 7, |
|
Y |
|
48 |
Block I, |
Y |
Y |
|
49 |
|
Y |
Y |
|
50 |
Block 2, |
Y |
Y |
|
51 |
Block 5, |
Y |
Y |
|
52 |
Block 4, |
Y |
Y |
|
53 |
Block 8, |
|
Y |
|
61 |
Block A, |
|
Y |
|
62 |
|
Y |
|
|
63 |
|
Y |
|
* Both 1/F and 7/F of NSR 18 are
assessed. 7/F is the lowest level within
the Line of Sight of the HOM Station construction site (WS15a) at the start of
excavation, while 1/F will be exposed to the HOM Station excavation works only after
the slope at
# NSR 12 is included in the construction
noise assessment as the planned school is anticipated to be completed by 2010
and thus it could be affected by the construction of the KTE.
7.5.1.1
The proposed KTE is an extension of the KTL from Yau
Mei Tei to Whampoa via Ho Man Tin. The project
site is located in the urban district of
7.6
Identification of Environmental Impact
7.6.1
Construction
Phase
Overview
7.6.1.1
The potential source of noise impact during the
construction phase of the KTE project would be the use of PME for various
construction activities. As broadly
indicated in the construction programme in Appendix
3.2, the
construction of the KTE project would be tentatively undertaken from 2010/2011
to 2015. The key elements involving
construction activities to be carried out at ground surface relevant to the
construction air-borne noise assessment include:
· Open-cut station boxes at HOM Station;
· Cut-and-cover station boxes at WHA Station;
· Tunnel ventilation building in combination with the WAB at Club de Recreio;
· Entrance structures/lift entrances of stations;
· Ventilation shafts of stations; and
· Entrance adits of stations.
7.6.1.2
Besides the main works sites shown in Figures 7.1-7.9 where major works activities will be undertaken,
there are also six works areas as summarised in Section
3 (refer to Table 3.1 and Appendix 3.1). It should
be noted that three of these works areas (WA2a, WA6 and WA15; Figures 7.4, 7.5, 7.6 and 7.9 refers) would be designated
for use as site offices and storage of materials only and there would be no use
of PME anticipated, except for the initial
establishment works. One of the remaining works areas
is designated for use as a barging point in Figure
7.8 (WA14), at
which initial site establishment works and loading/unloading of C&D
materials would occur. The last works
area is a temporary magazine site shown in Figure
3.10 (WA12a
and WA13) which will be used for storage/delivery of explosives. Since there are no NSRs within 300m from the
temporary magazine site, the construction air-borne noise impact was not
assessed.
Muckout Points
7.6.1.3
There would be 5 groups of works sites with construction
shafts or haul roads through which excavated spoil from tunnelling works would
be removed or mucked out (Table 3.2 in Section 3):
·
WS1 (
· WS7a1 (WAB at Club de Recreio) (Figure 7.11);
· WS15a (HOM Station) (no dedicated muckout point is assigned);
·
WS26a (
· WS30 and WS33 (WHA Station) (no dedicated muckout points are assigned).
7.6.1.4
Due to the intensity of the construction activities
at these locations, specific attention to the construction noise mitigation
measures has been made and at all dedicated muckout points enclosures will be
installed to mitigate the air-borne noise impact during construction phase
which will be discussed in Section 7.9.2. However, it should
be noted that not all NSRs would be shielded by the enclosures due to the
existence of openings for the access of trucks.
Station Construction
7.6.1.5
HOM Station and WHA Station will be constructed mainly
using the open-cut method and cut-and-cover method, respectively. No dedicated haul roads or muckout points will
be assigned at the station works areas as spoil will be removed through access
points which will change in location depending on the process of the works
throughout the construction phase.
Tunnel Construction
7.6.1.6
As the tunnel construction would be carried out
underground, it would be considered to be fully enclosed and would not induce any
air-borne construction noise impacts on the NSRs.
Barging Point
7.6.1.7
The barging point located at Hung Hom Finger Pier would
potentially induce noise impacts to the nearby NSRs during delivery and loading
of construction and demolition materials throughout the construction phase.
7.6.1.8
The barging point will be used by both KTE and SCL projects
and therefore cumulative impact at the barging point will be assessed.
Rock Crushing Activities
7.6.1.9
There will be rock crushing activities to be carried
out as part to the KTE project and one rock crushing facilities will be located
at WS15a and two at WA14. The capacity
of each rock crusher is anticipated to be about 800ton/hr. Two of the rock crushers will be located within
the barging point in Hung Hom Finger Pier and used by both KTE and SCL projects. Therefore, cumulative impacts of the rock
crushers at the barging point will be assessed.
7.6.1.10
These rock crushing facilities are designated
projects under Section G.2 of Part I, Schedule 2 of the EIAO and as such, specific
attention to construction noise mitigation measures has been made at these locations
to mitigate the potential air-borne noise impacts during their use. In each case, a full enclosure of the rock
crushing activities will be provided (see Figure
3.38).
Drill and Blast Operation and Spoil Removal
7.6.1.11
The tunnel sections of the KTE alignment will
largely be excavated by the drill-and-blast method (WS3, WS10, WS28 and WS29 in
Table 3.2). The
blasting, as well as the removal of debris and rocks after blasting, would be
carried out during non-restricted hours.
The broken rock would be removed from the underground by dump trucks and
subsequently transported to the designated barging point at the Hung Hom Finger
Pier (WA14). Nonetheless, it should be
noted that no noise assessment would be required for blasting works in this EIA
Study.
Key PMEs Identified as Major Noise Sources
7.6.1.12
The key PMEs that would result in elevation of
construction noise impact at various works sites are shown in Table
7.5, and these are considered to be the dominant noise sources.
Table 7.5: PMEs
Identified as Major Noise Sources
|
Name of PMEs |
SWL of the PME, dB(A) |
|
Rock Drill |
123 |
|
Breaker |
122 |
|
Scraper |
119 |
|
Rock Crusher † |
118 |
|
Tractor |
118 |
|
Dump Truck |
117 |
|
Bulldozer |
115 |
|
Breaker, mini-robot mounted |
115 |
|
Piling, vibrating hammer |
115 |
|
Saw/groover, concrete (petrol) |
115 |
|
Compressor and Pneumatic Drilling Rig |
114 |
† SWL for Rock Crusher is made with reference to the approved EIA
Report for West Island Line
7.6.2
Operational Phase
7.6.2.1
Air-borne operational noise will be generated by
fixed plant sources such as the ventilation shafts, chillers and coolers. Other building services equipment, such as
pumps, transformers, emergency generators will be located within plant rooms
which would be located underground or at least fully
enclosed.
7.6.2.2
There are 5 groups of ventilation shafts for HOM
Station, 5 groups for WHA Station and 1 group combined with the WAB at Club de
Recreio. Detailed locations are shown in
Figures
7.13 – 7.19 and are listed as follows:
·
VSH-1a, VSH-1a-1 and VSH-1b – Tunnel Ventilation Shaft located at
Entrance of HOM Station at
· VSH-2 – Cooling Tower Intake & Exhaust located at Entrance D of HOM Station at Yan Fung Street. VSH-2 comprises two groups of louvers, the intake and exhaust for the cooling tower. As both groups of louvers are oriented towards the same direction, their cumulative impacts were considered and assessed as one single group;
· VSH-3 – Ventilation Shaft located at Entrance C of HOM Station facing Chatham Road North. VSH-3 is the Station Ventilation Shaft located next to the cooling tower intake and exhaust. The louver follows the station outline and resulting in facing three directions. Their cumulative impacts were considered separately;
·
VSH-4 – Ventilation Shaft next
to VSH-3.
VSH-4 is a ventilation shaft between VSH-3 and VSH-5 facing
·
VSH-5 – Tunnel Ventilation Shaft located at the south end of the
station.
VSH-5 is a ventilation shaft facing
·
VSH-6 – Elevated Ventilation Shaft located at Entrance B of the station. VSH-6
is a ventilation shaft facing
· VSH-7 – Station Ventilation Shaft located under Entrance B of the station. VSH-7 is a ventilation shaft under the footbridge of Entrance B facing north in an opposite direction to VSH-8.
·
VSH-8 – Station Ventilation Shaft located under Entrance B of the
station.
VSH-8 is a ventilation shaft under the
footbridge of Entrance B facing south towards
·
VSH-9 – Station Ventilation Shaft located at the south end of the
station.
VSH-9 is a ventilation shaft facing south
towards
·
VSH-10 – Station Ventilation Shaft located at the south end of the
station.
VSH-10 is a ventilation shaft facing south
towards
·
VSH-11 – Station Ventilation Shaft located at the south end of the
station.
VSH-11 is a ventilation shaft facing south
towards
·
VSW-1 – Integrated with Entrance
A at Hung Hom Road adjacent to On Wah Building. VSW-1 is a ventilation shaft with multiple
louvers facing South-eastward and North-westward affecting On Wah Building and
·
VSW-2 – Integrated with
designated emergency entrance at Shung King Street adjacent to Whampoa Plaza. VSW-2 is a ventilation
shaft with multiple louvers facing North-eastward and North-westward affecting Block
8 and 13 of Bauhinia Mansions.
·
VSW-3 –Standalone
ventilation shaft at
·
VSW-4 – Integrated with Entrance
B2 at Tak On Street outside GCE Past Student’s
·
VSW-5a and VSW-5b – A pair
of standalone ventilation shafts outside Harbourfront Landmark. VSW-5 is a pair of ventilation
shafts located outside Harbourfront Landmark next to the southern end of
· VSWAB-1 to VSWAB-10 – Integrated with the WAB in Club de Recreio. VSWAB is a group of ventilation shafts integrated with the WAB at Club de Recreio with multiple louvers in all directions.
7.7.1.1 Construction of the KTE project would be on-going between early 2011 and 2015 with its commissioning in 2015. In addition to the KTE project itself, there are various other projects that are planned to be constructed concurrently and these have been taken into account in the construction air-borne noise assessment.
7.7.1.2 The assessment of the cumulative impacts has been based on the best available information during the time of submission and any changes to the programmes of the concurrent projects will be reflected in the subsequent submissions for those projects. Details of the KTE project construction programme and the concurrent projects have been provided in Section 3 of this EIA Report and summarised below:
· The planned dormitory of the Hong Kong Polytechnic University (construction period: 2009-2012) – There is currently no detailed information on the construction works available for the assessment and, as such, this concurrent project has not been assessed for any cumulative impacts with the KTE project (Figure 3.19);
· Central Kowloon Route (CKR) – According to the HyD (refer to Appendix 3.3), the construction programme and commissioning time of CKR are under review, and the types of construction works and the respective construction plant inventories within the construction period are not available yet;
· Shatin to Central Link (SCL) – Tai Wai to Hung Hom Section (tentative construction period: 2011-2017) – There are proposed works sites for the cut-and-cover tunnel for the construction of SCL – Tai Wai to Hung Hom Section near Chatham Road North which are in the immediate neighbourhood of the southern end of the works sites for HOM Station of the KTE project as shown in Figures 3.21 and 3.22. The assessment of the cumulative impacts for SCL has been based on the best available information during the time of submission and any changes to the programme will be reflected in the subsequent submissions for this project. In addition, as SCL – Tai Wai to Hung Hom Section will also share the same barging point at Hung Hom Finger Pier cumulative construction air-borne noise impact at Harbourfront Horizon has also been assessed;
· Shatin to Central Link – Mongkok East to Hung Hom Section (tentative construction period: 2011-2020) – There would be some works sites proposed for the cut-and-cover tunnel of the SCL – Mongkok East to Hung Hom Section near the existing East Rail Line (EAL) adjacent to Princess Margaret Road and Oi Man Estate which are close to the works sites of the KTE project for HOM Station as shown in Figure 3.23. The assessment of the cumulative impacts for SCL has been based on the best available information during the time of submission and any changes to the programme will be reflected in the subsequent submission for this project. In addition, as SCL – Mongkok East to Hung Hom Section will also share the same barging point at Hung Hom Finger Pier cumulative construction air-borne noise impact at Harbourfront Horizon has also been assessed; and
· Essential Public Infrastructure Works (EPIW) for the KTE project (tentative construction period: 2011-2015) – There would be some works sites allocated for the construction of the EPIW including subways and footbridges connecting HOM Station and Oi Man Estate and Ho Man Tin Estate, Public Transport Facilities along Chung Hau Street at the northwest of HOM Station and a covered footbridge stretching from HOM Station over Yan Fung Street, Chatham Road North and above the existing footbridge as shown in Figure 3.24.
7.7.1.3 The EPIW involves 4 main components:
·
Two
connections to both Oi Man Estate and Ho Man Tin Estate (including the subway
from HOM Station across Chung Hau Street and the covered walkway along Chung
Hau Street, Chung Yi Street and Fat Kwong Street) and the associated slope
stabilisation works;
·
Public
transport facility and lay-bys at
·
Passageway
and covered footbridge over
7.7.1.4 However, as there are no NSRs identified for construction air-borne noise assessment in the close proximity of the works site, the EPIW for Connections to Oi man Estate and Ho Man Tin Estate have not been included in the assessment for cumulative construction air-borne noise impacts.
7.8.1
Construction
Phase
7.8.1.1
In accordance with the EIAO-TM, the methodology
outlined in the GW-TM has been used for the construction noise assessment. The general approach is summarised below:
· Locate the NSRs which would most likely be affected by the noise from construction works;
· Determine the items of PME for each discrete construction activity, based on the available information or agreed plant inventories;
· Assign sound power levels (SWLs) to the proposed PME according to the GW-TM or other sources;
· Calculate the distance attenuation and screening effects to NSRs from the notional noise source;
· Predict the construction noise levels at NSRs in the absence of any mitigation measures; and
· Include a 3dB(A) façade correction to the predicted noise levels in order to account for the façade effect at each NSR.
7.8.1.2
At WHA Station, construction is proposed to be
carried out by the cut-and-cover method and is divided into up to 6 phases. In each phase, construction is divided into a
number of sub-zones where construction activities would be on-going. PMEs are assumed to be spread among the
sub-zones. The details of sub-zoning of
works sites, distances between notional sources and all NSRs adopted for
calculation are shown in Appendix 7.2.
7.8.1.3
The SWLs of the PME were taken from Table 3 of
the GW-TM. Where no SWL is given in the
GW-TM, reference was made to the British Standard 5228: Part
1:2009 Noise Control on Construction and Open Sites and previous similar
studies or from other EIA reports or measurements taken in
other relevant studies.
7.8.1.4
Groups of PME were assigned for various construction
activities of the KTE project
and the plant
inventory is presented in Appendix 7.3. The design consultant of the KTE
project has
confirmed this plant inventory as being practical and adequate for
completing the construction works within the scheduled
timeframe. The plant inventory has been
provided as one option which is considered technically feasible, and would
represent a realistic worst-case scenario for assessment
purposes. In the detailed design stage, the
Contractor may propose an alternative plant schedule(s), should it be considered
appropriate. However, the alternative
plant inventory should be reviewed and verified by the Environmental Team and
Independent Environmental Checker respectively.
7.8.1.5
During excavation for HOM Station and WHA Station,
PMEs will be located below station shafts / boxes and be shielded by the pipe
pile wall. Assessment will not consider
the change of elevation during excavation and PMEs are assumed to stay at the
level where construction works starts.
The typical station shafts / boxes to illustrate the noise reduction of
the shielding can be seen in Figure 7.20. It is anticipated that due to the shielding
effect from the pipe pile walls, a -10dB(A) attenuation would be achievable.
7.8.1.6
As the tunnel construction would be carried out
underground, it would be considered to be fully enclosed and would induce no
air-borne construction noise impact to the NSRs.
7.8.1.7
For NSR 18, as the slope at
7.8.1.8
The WS27 is a ring shaped works site surrounding
WS26a and WA15 and in accordance with GW-TM, the notional source shall not consider
the whole work site and instead the closest portion to the NSR being assessed
has been considered.
7.8.2
Operational
Phase
7.8.2.1
Operation air-borne noise levels were determined by
adopting standard acoustic principles.
The formula for calculating the maximum permissible SWLs for the fixed plant is:
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) and
= 20 log D + 8
FC = Façade Correction in dB(A) and =
3dB(A)
BC = Barrier Correction in dB(A)
D = Distance in metres
7.8.2.2
A worst-case scenario was assumed where
all the fixed plant positioned within the same area are assumed to be operated
at the same time using the back-calculation of the maximum SWL. In addition, the plant was assessed
individually where it is not situated close to
others.
7.8.2.3
Screening corrections from buildings or other
structures and prevailing noise levels obtained by measurements (daytime,
evening and night-time) were taken into account in the noise calculations. For instance, according to the GW-TM,
effective barriers could result in noise reduction of 5/10dB(A) for the fixed
plant depending on the line of sight of the representative NSRs. A positive 3dB(A) correction would be added
to predicted noise levels at the NSRs due to the façade effect.
7.8.2.4
No corrections have been applied for tonality,
intermittency or impulsiveness. If the
noise exhibits any of these characteristics during the operation of the plant,
the noise limit should be reduced in accordance with the recommendation given
in Section 3.3 of IND-TM.
7.9
Air-borne Construction Noise Assessment
7.9.1
Results
7.9.1.1
As illustrated in the construction programme (see Section 3.7), various works activities for KTE would be carried out concurrently
during a particular period. The
unmitigated construction noise levels at representative NSRs have been predicted
as summarised in Table
7.6. Detailed
results are presented in Appendix 7.4 and the predicted
SPL for difference directions of NSRs (if any) are also shown, although they are
discussed collectively as a single NSR.
Table 7.6: Predicted
Unmitigated Air-borne Construction Noise Levels for Selected NSRs
|
NSR |
Name |
Maximum Predicted
Construction Noise Level, dB(A) |
EIAO -TM Noise Criteria,
dB(A) |
|
NSR 5 |
|
82 |
75 |
|
NSR 6 |
|
86 |
70/65 |
|
NSR 11 |
|
84 |
75 |
|
NSR 12 |
Primary School at |
83 |
70/65 |
|
NSR 13a |
Parc Palais Block 1 |
76 |
75 |
|
NSR 13b |
Parc Palais Block 3 |
72 |
75 |
|
NSR 13c |
Parc Palais Block 6 |
65 |
75 |
|
NSR 16 |
|
79 |
70/65 |
|
NSR 18-1 |
Yee Fu Building (1/F) |
90 |
75 |
|
NSR 18-7 |
Yee Fu Building (7/F) |
91 |
75 |
|
NSR 19 |
|
81 |
75 |
|
NSR 20 |
Caritas Bianchi |
85 |
70/65 |
|
NSR 21 |
Lok Ka House |
84 |
75 |
|
NSR 22a-1 |
Flat A, Lok Do
Building |
86 |
75 |
|
NSR 22b-1 |
Flat B, Lok Do Building |
||
|
NSR 23 |
|
83 |
70/65 |
|
NSR 27a |
Block Y, Ki Fu
Building, Whampoa Estate |
94 |
75 |
|
NSR 27b |
|||
|
NSR 28 |
Block H, On |
95 |
75 |
|
NSR 29a |
Block 9, |
90 |
75 |
|
NSR 29b |
|||
|
NSR 30a |
Block 1, |
91 |
75 |
|
NSR 30b |
|||
|
NSR 31a |
Block 5, |
91 |
75 |
|
NSR 31b |
|||
|
NSR 31c |
|||
|
NSR 32 |
Block 13, |
89 |
75 |
|
NSR 33 |
Block 1, |
92 |
75 |
|
NSR 34a |
|
89 |
70/65 |
|
NSR 34b |
|||
|
NSR 35a |
|
88 |
70/65 |
|
NSR 35b |
|||
|
NSR 35c |
|||
|
NSR 36 |
Harbourfront Landmark |
82 |
75 |
|
NSR 39 |
Harbourfront Horizon |
88 |
75 |
|
NSR 44 |
|
77 |
75 |
|
NSR 48a |
Block I, |
97 |
75 |
|
NSR 48b |
|||
|
NSR 49 |
|
85 |
70/65 |
|
NSR 50 |
Block 2, |
92 |
75 |
|
NSR 51a |
Block 5, |
91 |
75 |
|
NSR 51b |
|||
|
NSR 52 |
Block 4, |
83 |
75 |
|
NSR 62 |
|
81 |
75 |
|
NSR 63 |
|
77 |
70/65 |
Notes: Noise Limits of Leq(30min) for Schools is
70dB(A) for normal periods; 65dB(A) during exam periods.
Numbers in bold underline (e.g. 80) signify an exceedance of the
noise criteria.
Numbers in italic (e.g. 68) signify an exceedance of the noise criteria during examination
periods only.
7.9.1.2
Without mitigation, impacts of up to 22dB(A) exceeding
the relevant criteria would be anticipated.
The high level of construction noise impacts would be due to the limited
separation distance between NSRs and works sites. The feasibility of providing noise reduction
measures to further reduce the noise impacts has been examined and discussed
below.
PMEs Used in Construction Works
7.9.2.1
The results in Table
7.7 above
indicate that significant construction noise impacts would be anticipated at
most of the NSRs under the unmitigated scenario. Suitable noise mitigation measures are,
therefore, required to minimise the construction noise impact. The measures applied are presented in Appendix 7.5 which include:
· Use of quiet plant as per the following list. These are capable of a 3-14dB(A) reduction of noise;
|
PME |
Reference |
SWL, dB(A) |
|
Air
Compressor |
CNP 003 |
104 |
|
Asphalt
Paver |
BS D8/24 |
101 |
|
Breaker |
BS D8/13 |
110 |
|
Bulldozer |
BS D3/27 |
109 |
|
Concrete
lorry mixer |
BS D6/33 |
96 |
|
Concrete
Pump / Grout Pump |
BS D6/36 |
106 |
|
Crane |
BS D7/114 |
101 |
|
Cutter,
circular, steel (electric) |
BS D7/78 |
106 |
|
Dump
Truck |
BS D9/39 |
103 |
|
Backhoe |
BS D3/79 |
101 |
|
Generator |
CNP 103 |
95 |
|
Vibrating
Poker, hand-held (electric) |
BS D6/40 |
98 |
|
Rock
Drill † |
Ref 1 |
108 |
|
Roller,
vibratory |
BS D8/30 |
101 |
|
Scraper |
BS D9/16 |
108 |
|
Water pump (electric) |
CNP 283 |
85 |
† SWL for Rock Drill is made with reference to the approved EIA Report
for Tsim Sha Tsui Station Northern Subway
· Use of temporary or fixed noise barriers with a surface density of at least 10kg/m2 to screen noise from movable and stationary plant. With reference to EIAO Guidance Note No.9/2004, noise reduction of 5dB(A) and 10dB(A) can be achieved by noise barriers for movable and stationary plant respectively;
· Use of enclosures with covers at top and three sides and a surface density of at least 10kg/m2 to screen noise from generally static noisy plant such as air compressors. With reference to EIA Guidance Note No.9/2004 this is capable of a 15dB(A) reduction of noise;
· Use of acoustic fabric for the silent piling system, drill rigs, rock drills etc. Experience from approved EIA Report for Tsim Sha Tsui Station Northern Subway (EIA 154/2008) showed that this is capable of a 10dB(A) reduction of noise;
· Proper fitting of silencers and mufflers on the ventilation fans. Experience from approved EIA Report for Tsim Sha Tsui Station Northern Subway (EIA 154/2008) showed that this is capable of a 15dB(A) reduction of noise; and
· Utilisation of decking for WHA Station where PMEs would be operating under temporary traffic decking. The area where traffic decking is feasible is shown in Figure 7.21. Experience from approved EIA Report for West Island Line (EIA153/2008) showed that this is capable of a 20dB(A) reduction of noise.
Muckout Activities
7.9.2.2
Noise enclosures are proposed for all muckout points
to mitigate the noise generated during the construction phase. The typical setup of an enclosure at a
mucking out point is presented in Figure 7.22. It is anticipated that the enclosure would
perform in a similar manner to the noise closure suggested for the PMEs above
and, therefore, a 15dB(A) reduction of noise has been assumed for this
assessment.
Rock Crushing Activities
7.9.2.3
Noise enclosures are proposed to be installed for
all rock crushers to mitigate the noise generation during the construction
phase. The typical setup of an enclosure
has been given in Figure 3.38.
It is anticipated that the enclosure would perform in a similar manner to
the noise closure suggested for the PMEs above and, therefore, would be capable
of a 15dB(A) reduction in noise.
7.9.2.4
Table 7.7 summarises all mitigation measures to be adopted
for PMEs and their respective reduction in noise levels during the construction
noise assessment.
Table 7.7: Mitigation
Measures and Assumed Effectiveness for PMEs
|
PME |
Mitigation Measures |
Reduction Level |
|
Compressor and Pneumatic Drilling Rig |
Acoustic Fabric |
15 |
|
Piling, vibrating hammer |
Acoustic Fabric |
15 |
|
Rock Drill |
Acoustic Fabric |
15 |
|
Silent Piling System |
Acoustic Fabric |
15 |
|
Air Compressor |
Enclosure Type Noise Barrier |
15 |
|
Rock Crusher |
Enclosure Type Noise Barrier |
15 |
|
Concrete pump |
Fixed Noise Barrier |
10 |
|
Circular Saw, bench mounted |
Fixed Noise Barrier |
10 |
|
Truck |
Fixed Noise Barrier |
10 |
|
Bar bender and cutter (electric) |
Fixed Noise Barrier |
10 |
|
Conveyor belt |
Fixed Noise Barrier |
10 |
|
Generator, Super Silenced |
Fixed Noise Barrier |
10 |
|
Grout Pump |
Fixed Noise Barrier |
10 |
|
Saw, wire |
Fixed Noise Barrier |
10 |
|
Water Pump, Submersible (Electric) |
Fixed Noise Barrier |
10 |
|
Hydraulic Jack with Pump |
Fixed Noise Barrier |
10 |
|
Ventilation Fan |
Silencer |
15 |
|
Wheeled Excavator/Loader |
Temporary Noise Barrier |
5 |
|
Crane |
Temporary Noise Barrier |
5 |
|
Hydraulic Breaker |
Temporary Noise Barrier |
5 |
|
Scraper |
Temporary Noise Barrier |
5 |
|
Breaker, hand-held, mass > 10kg and < 20kg |
Temporary Noise Barrier |
5 |
|
Breaker, hand-held, mass >= 20kg and <= 35kg |
Temporary Noise Barrier |
5 |
|
Compactor, vibratory |
Temporary Noise Barrier |
5 |
|
Drill, percussive, hand-held (electric) |
Temporary Noise Barrier |
5 |
7.9.2.5
Due to the necessity of access entrances, not all
NSRs would be shielded by the the enclosures.
Table
7.8 below shows the NSRs which will be shielded by the
enclosure and receive an additional 15dB(A) attenuation of the predicted SWL
for the PMEs used in the mucking out operations.
Table 7.8: NSRs
to be Shielded by Noise Enclosures at Muckout Points
|
NSR |
Muckout Operation and Location |
Noise Level Reduction (dB(A)) |
|
NSR 5 |
1.6 Remove spoil through
existing GAR substation hatch |
15 |
|
NSR 6 |
1.6 Remove spoil through
existing GAR substation hatch |
15 |
|
NSR 12 |
4.10 Remove spoil from
YMT to HMT tunnels including KTE east station platform via WAB shaft |
15 |
|
NSR 13a |
4.10 Remove spoil from
YMT to HMT tunnels including KTE east station platform via WAB shaft |
15 |
|
NSR 13b |
4.10 Remove spoil from
YMT to HMT tunnels including KTE east station platform via WAB shaft |
15 |
|
NSR 19 |
7.12 Remove spoil from
HMT to WHA tunnel including KTE station platform via FKSP shaft |
15 |
|
NSR 22 |
7.12 Remove spoil from
HMT to WHA tunnel including KTE east station platform via FKSP shaft |
15 |
|
NSR 23 |
7.12 Remove spoil from
HMT to WHA tunnel including KTE east station platform via FKSP shaft |
15 |
7.9.2.6
In addition to the mitigation measures listed above,
there are also some good site practices that can further reduce the noise
levels at NSRs. However, they are
non-quantifiable and, thus, not included in the noise level calculations. These include:
· Only well-maintained plant should be operated on-site and plants should be serviced regularly during the construction period;
· Mobile plant, if any, should be sited as far from NSRs as possible;
· Plant known to emit noise strongly in one direction should, wherever possible, be properly orientated so that the noise is directed away from the nearby NSRs;
· Use of site hoarding as a noise barrier to screen noise at low level NSRs;
· Machines and plant that may be in intermittent use should be shut down between works periods or should be throttled down to a minimum; and
· Any material stockpiles and other structures should be effectively utilised, wherever practicable, to screen the noise from on-site construction activities.
7.9.2.7
Thus, the construction works have been mitigated
using the above mentioned measures, and the mitigated construction noise levels
at representative NSRs have been predicted and summarized in Table
7.9 below.
Detailed results are presented in Appendix
7.6.
Table 7.9: Predicted Mitigated Air-borne
Construction Noise Levels for Selected NSRs
|
NSR |
Name |
Maximum
Predicted Construction Noise Level, dB(A) |
EIAO-TM Noise Criteria, dB(A) |
|
NSR 5 |
|
74 |
75 |
|
NSR 6 |
|
75 |
70/65 |
|
NSR 11 |
|
73 |
75 |
|
NSR 12 |
Primary School at |
70 |
70/65 |
|
NSR 13a |
Parc Palais Block 1 |
62 |
75 |
|
NSR 13b |
Parc Palais Block 3 |
59 |
75 |
|
NSR 13c |
Parc Palais Block 6 |
53 |
75 |
|
NSR 16 |
|
65 |
70/65 |
|
NSR 18-1 |
Yee Fu Building (1/F) |
77 |
75 |
|
NSR 18-7 |
Yee Fu Building (7/F) |
77 |
75 |
|
NSR 19 |
|
69 |
75 |
|
NSR 20 |
Caritas Bianchi |
72 |
70/65 |
|
NSR 21 |
Lok Ka House |
70 |
75 |
|
NSR 22a |
Lok Do Building |
72 |
75 |
|
NSR 22b |
|||
|
NSR 23 |
|
70 |
70/65 |
|
NSR 27a |
Block Y, Ki Fu Building,
Whampoa Estate |
83 |
75 |
|
NSR 27b |
|||
|
NSR 28 |
Block H, On |
78 |
75 |
|
NSR 29a |
Block
9, Bauhinia Mansions, Whampoa Garden Site 11 |
79 |
75 |
|
NSR 29b |
|||
|
NSR 30a |
Block 1, |
78 |
75 |
|
NSR 30b |
|||
|
NSR 31a |
Block 5, |
80 |
75 |
|
NSR 31b |
|||
|
NSR 31c |
|||
|
NSR 32 |
Block
13, Bauhinia Mansions, Whampoa Garden Site 11 |
79 |
75 |
|
NSR 33 |
Block
1, Oak Mansions, Whampoa Garden Site 5 |
82 |
75 |
|
NSR 34a |
|
78 |
70/65 |
|
NSR 34b |
|||
|
NSR 35a |
|
76 |
70/65 |
|
NSR 35b |
|||
|
NSR 35c |
|||
|
NSR 36 |
Harbourfront Landmark |
74 |
75 |
|
NSR 39 |
Harbourfront Horizon |
75 |
75 |
|
NSR 44 |
|
65 |
75 |
|
NSR 48a |
Block I, |
81 |
75 |
|
NSR 48b |
|||
|
NSR 49 |
|
71 |
70/65 |
|
NSR 50 |
Block
2, Oak Mansions, Whampoa Garden Site 5 |
83 |
75 |
|
NSR 51a |
Block 5, |
82 |
75 |
|
NSR 51b |
|||
|
NSR 52 |
Block 4, |
75 |
75 |
|
NSR 62 |
|
67 |
75 |
|
NSR 63 |
|
63 |
70/65 |
Notes: Noise Limits of Leq(30min) for
Schools is 70dB(A) for normal periods; 65dB(A) during exam periods.
Numbers in bold underline ( e.g.
77) signify an exceedance of
the noise criteria.
Numbers in italic (e.g. 68) signify an exceedance of the noise criteria during examination
periods only.
7.9.2.8
With the implementation of the above recommended
mitigation measures, the predicted construction noise level could be reduced by
up to 17dB(A). However, the construction
noise levels for the NSRs near HOM Station and WHA Station are still predicted
to exceed the criteria. The NSRs for which exceedances are predicted to occur
are summarised in Table
7.10.
Table 7.10: Summary
of Exceedances at Representative NSRs
|
NSR |
Name |
Maximum Predicted Residual Impact, dB(A) |
EIAO-TM Noise Criteria, dB(A) |
Duration,
months |
|
NSR 6 |
|
5 (10) |
70 / 65 |
4(12.5)# |
|
NSR 12 |
Primary School at |
0 (5) |
70 / 65 |
0(19.5) # |
|
NSR 18-1 |
Yee Fu Building (1/F) |
2 |
75 |
6.5 |
|
NSR 18-7 |
Yee Fu Building (7/F) |
2 |
75 |
6.5 |
|
NSR 20 |
Caritas Bianchi |
2 (7) |
70 / 65 |
7(31) # |
|
NSR 23 |
|
0 (5) |
70 / 65 |
0(15.5) # |
|
NSR 27 |
Block Y, Ki Fu Building, Whampoa Estate |
8 |
75 |
16 |
|
NSR 28 |
Block H, On |
3 |
75 |
7.5 |
|
NSR 29 |
Block 9, Bauhinia Mansions, Whampoa
Garden Site 11 |
4 |
75 |
9.5 |
|
NSR 30 |
Block 1, |
3 |
75 |
12.5 |
|
NSR 31c |
Block 5, |
5 |
75 |
20 |
|
NSR 32 |
Block 13, Bauhinia Mansions,
Whampoa Garden Site 11 |
4 |
75 |
22 |
|
NSR 33 |
Block 1, Oak Mansions, Whampoa
Garden Site 5 |
7 |
75 |
13 |
|
NSR 34 |
|
8 (13) |
70 / 65 |
28(43) # |
|
NSR 35 |
|
6 (11) |
70 / 65 |
20(31.5) # |
|
NSR 48 |
Block I, |
6 |
75 |
13 |
|
NSR 49 |
|
1 (6) |
70 / 65 |
10(20.5) # |
|
NSR 50 |
Block 2, Oak Mansions, Whampoa
Garden Site 5 |
8 |
75 |
24 |
|
NSR 51 |
Block 5, |
7 |
75 |
24 |
Notes: Noise Limits of Leq(30min) for Schools is
70dB(A) for normal periods; 65dB(A) during exam periods.
Numbers in parentheses signify residual impacts
during examination periods.
NSRs with more than one façade (e.g. NSR 29a and 29b)
are only counted as one NSR.
# Denotes
maximum construction period where exceedances could occur but only if an exam is
being undertaken during this period.
7.9.2.9
Two schools (NSR 12 and NSR 23) will show
exceedances during examination periods only. Scheduling of noisy
construction works outside school examination periods would reduce the noise
impacts on the NSRs and this is proposed. This measure relieves the
need to incorporate more stringent noise mitigation measures required to ensure
compliance with the construction noise criterion and would avoid residual
impacts.
7.9.2.10
There are a total of seventeen NSRs that show
exceedances of the relevant construction noise criteria of 1dB(A) –
8dB(A). Five of them are schools (NSR 6,
NSR 20, NSR 34, NSR 35 and NSR 49) which would be subject to residual impacts
of 1dB(A) – 7dB(A). The other twelve
NSRs are residential which will be subject to residual impacts of 2dB(A) –
8dB(A).
7.9.2.11
Additional barriers are not considered practical for
most of the works sites. For example, for
the slope stabilization works at WS2 and WS27, substantial noise barriers would
be impractical due to site constraints as well as potential secondary impacts
as a consequence of building such barriers with a large footing. For works sites at HOM Station, the open cut area
at WS15a is more than 250m in length with slope ranges from 30° to 80°. These site conditions make the erection of
tall noise barriers infeasible due to lack of suitable area for foundations. As short noise barriers will not be able to
provide sufficient shielding for the PMEs at the centre of the work site, fixed
noise barriers would not be considered practical at WS15a.
7.9.2.12
For the works sites at WHA, due to the lack of space
between the works sites and the pedestrian walkway at Tak On Street,
substantial noise barriers with large footings are also considered not
practical.
7.9.2.13
Utilisation of temporary construction facilities
including site offices would also be limited by the location of works
areas. For Fat Kwong Street Playground,
works area is divided into WA15 at the northwest side where the site offices
and storage area will be located. The
mucking out point is located in WS26a to the south and is close to the edge of
the works site. As such, there is
limited space for any site offices to be located around the mucking out point
in order to provide additional attenuation to the NSRs near by. Figure 7.12 showed the site layout of
WS26a and WA15.
7.9.2.14
All reasonably practicable mitigation measures have,
therefore, been proposed but some residual impacts will still remain. Residual impacts are further discussed in
Section 7.11.
7.9.3
Cumulative Construction
Noise Assessment
7.9.3.1
All concurrent projects which may contribute to air-borne
noise impacts on NSRs during its construction and operational phases have been
identified in Section 3. Referring
to the respective draft EIA Reports, cumulative impacts have been presented in Appendix 7.6. A summary of the results is
presented in Table 7.11 below.
Table 7.11: Cumulative
Construction Noise Assessment with Concurrent Projects
|
NSR |
Source of Cumulative Impact |
Maximum Cumulative Construction Noise Level,
dB(A) |
Exceedance, dB(A) |
||
|
EPIW |
SCL- THS |
SCL- MHS |
|||
|
13a |
-- |
-- |
ü |
63 |
-- |
|
13c |
-- |
-- |
ü |
68 |
-- |
|
16 |
ü |
-- |
ü |
73 |
3 |
|
19 |
ü |
-- |
-- |
69 |
-- |
|
20 |
ü |
ü |
-- |
78 |
8 |
|
21 |
ü |
ü |
-- |
76 |
1 |
|
22 |
ü |
-- |
-- |
77 |
2 |
|
39 |
-- |
ü |
ü |
75 |
-- |
|
62 |
ü |
ü |
ü |
80 |
5 |
Note: EPIW = Essential
Public Infrastructure Works associated with the Project
SCL-THS = SCL
– Tai Wai to Hung Hom Section
SCL-MHS = SCL – Mongkok East to
Hung Hom Section
7.9.3.2
The cumulative impact with concurrent projects shows
exceedances of 1dB(A) to 8dB(A).
However, the dominant noise sources for them are:
· NSR 16 (due to SCL – Mongkok East to Hung Hom Section at 73dB(A));
· NSR 20 (due to EPIW at 77dB(A));
· NSR 21 (due to SCL – Tai Wai to Hung Hom Section at 75dB(A));
· NSR 22 (due to EPIW at 76dB(A)); and
· NSR 62 (due to SCL – Tai Wai to Hung Hom Section at 79dB(A)).
7.10
Operational Air-borne Noise Assessment
7.10.1
Assessment
Results
7.10.1.1
As all the rail tracks in the KTE project will be
underground, hence adverse operational air-borne train noise impacts would not
be anticipated. However, operational
noise will emanate from tunnel ventilation shafts. This EIA Study has established the maximum
allowable SWL for all above ground louvers and ventilation plant, with regard
to the separation distances and orientation from the nearest NSRs, as well as cumulative
noise impacts from other fixed noise sources. The detailed calculation is presented in Appendix 7.7.
7.10.1.2
These predicted maximum allowable SWLs which are
summarised in Table
7.12 should be implemented during the detailed design stage
to meet the relevant legislative requirements.
Table 7.12: Summary
of Maximum Allowable SWLs for Fixed Plant at Representative NSRs
|
Plant
Item |
Distance
to nearest NSR, (m) |
Maximum
Allowable Sound Power Level, dB(A) |
|
|
Daytime |
Night-time |
||
|
Running Tunnel from YMT to HMT |
|||
|
VSWAB
(VSWAB-1) |
66 |
87 |
77 |
|
VSWAB
(VSWAB-2) |
80 |
99 |
89 |
|
VSWAB
(VSWAB-3) |
83 |
99 |
89 |
|
VSWAB
(VSWAB-4) |
82 |
99 |
89 |
|
VSWAB
(VSWAB-5) |
82 |
100 |
90 |
|
VSWAB
(VSWAB-6) |
74 |
89 |
79 |
|
VSWAB
(VSWAB-7) |
76 |
89 |
79 |
|
VSWAB
(VSWAB-8) |
67 |
88 |
78 |
|
VSWAB
(VSWAB-9) |
67 |
88 |
78 |
|
VSWAB
(VSWAB-10) |
62 |
87 |
77 |
|
HOM Station |
|||
|
VSH-1a |
15 |
81 |
71 |
|
VSH-1a-1 |
14 |
81 |
71 |
|
VSH-1b |
23 |
85 |
75 |
|
VSH-2 |
36 |
89 |
79 |
|
VSH-3
(East Elevation) |
47 |
91 |
81 |
|
VSH-3
(South East Elevation) |
63 |
99 |
89 |
|
VSH-3
(South Elevation) |
86 |
100 |
92 |
|
VSH-4 |
96 |
100 |
90 |
|
VSH-5 |
97 |
100 |
90 |
|
VSH-6a |
38 |
92 |
82 |
|
VSH-6b |
38 |
92 |
82 |
|
VSH-7 |
118 |
90 |
80 |
|
VSH-8 |
113 |
101 |
92 |
|
VSH-9 |
103 |
100 |
90 |
|
VSH-10 |
114 |
101 |
92 |
|
VSH-11 |
88 |
99 |
89 |
|
WHA Station |
|||
|
VSW-1 (East
Elevation) |
25 |
92 |
82 |
|
VSW-1
(West Elevation) |
15 |
86 |
76 |
|
VSW-2
(North Elevation) |
21 |
88 |
78 |
|
VSW-2
(West Elevation) |
21 |
88 |
78 |
|
VSW-3
(North Elevation) |
32 |
94 |
93 |
|
VSW-3
(East Elevation) |
27 |
91 |
82 |
|
VSW-4
(West Elevation) |
9e |
79 |
69 |
|
VSW-5a |
25 |
90 |
80 |
|
VSW-5b |
28 |
91 |
81 |
7.10.1.3
Whilst it is generally considered too restrictive to
specify that the contractor has to use specific models of items of
equipment/plant, it is reasonable and practicable to set the noise performance
specifications for specific equipment/plant so that flexibility in the selection
of equipment is allowed. A pragmatic
approach would be to request that the contractors should independently verify
the noise levels of the equipment/plant to be used and demonstrate through
furnishing these results, that the equipment/plant to be used should meet the
requirements. The preference for
adopting quieter equipment/plant will be stipulated in the contract
specifications. It should be applied
whenever practicable to further eliminate the potential of noise impact from
ventilation buildings.
7.10.1.4
Cumulative SPL from all ventilation shafts at
representative NSRs are presented in Table 7.13 and detailed calculation is presented in Appendix 7.7.
Table 7.13: Cumulative
SPL from all Ventilation Shafts at Representative NSRs
|
NSR |
Louver |
Cumulative SPL from all Ventilation Shafts,
dB(A) |
Specific ANL Daytime (Night-time) |
|
|
Daytime |
Night-time |
|||
|
NSR 11 |
VSWAB (VSWAB-1) |
56 |
42 |
60 (50) |
|
|
VSWAB (VSWAB-2) |
|
|
|
|
|
VSWAB (VSWAB-3) |
|
|
|
|
|
VSWAB (VSWAB-4) |
|
|
|
|
|
VSWAB (VSWAB-5) |
|
|
|
|
|
VSWAB (VSWAB-6) |
|
|
|
|
|
VSWAB (VSWAB-7) |
|
|
|
|
|
VSWAB (VSWAB-8) |
|
|
|
|
|
VSWAB (VSWAB-9) |
|
|
|
|
|
VSWAB (VSWAB-10) |
|
|
|
|
NSR 12 |
VSWAB (VSWAB-1) |
55 |
41 |
55 (45) |
|
|
VSWAB (VSWAB-2) |
|
|
|
|
|
VSWAB (VSWAB-3) |
|
|
|
|
|
VSWAB (VSWAB-4) |
|
|
|
|
|
VSWAB (VSWAB-5) |
|
|
|
|
|
VSWAB (VSWAB-6) |
|
|
|
|
|
VSWAB (VSWAB-7) |
|
|
|
|
|
VSWAB (VSWAB-8) |
|
|
|
|
|
VSWAB (VSWAB-9) |
|
|
|
|
|
VSWAB (VSWAB-10) |
|
|
|
|
NSR 61 |
VSWAB (VSWAB-1) |
55 |
44 |
60 (50) |
|
|
VSWAB (VSWAB-2) |
|
|
|
|
|
VSWAB (VSWAB-3) |
|
|
|
|
|
VSWAB (VSWAB-4) |
|
|
|
|
|
VSWAB (VSWAB-5) |
|
|
|
|
|
VSWAB (VSWAB-6) |
|
|
|
|
|
VSWAB (VSWAB-7) |
|
|
|
|
|
VSWAB (VSWAB-8) |
|
|
|
|
|
VSWAB (VSWAB-9) |
|
|
|
|
|
VSWAB (VSWAB-10) |
|
|
|
|
NSR 18-1 |
VSH-1a |
56 |
46 |
60 (50) |
|
|
VSH-1a-1 |
|
|
|
|
|
VSH-1b |
|
|
|
|
|
VSH-2 |
|
|
|
|
|
VSH-3 (East Elevation) |
|
|
|
|
NSR 19 |
VSH-1a |
43 |
33 |
65 (55) |
|
|
VSH-1a-1 |
|
|
|
|
|
VSH-1b |
|
|
|
|
|
VSH-2 |
|
|
|
|
NSR 41 |
VSH-1a |
51 |
41 |
65 (55) |
|
|
VSH-1a-1 |
|
|
|
|
|
VSH-1b |
|
|
|
|
|
VSH-2 |
|
|
|
|
NSR 20 |
VSH-3 (East Elevation) |
62 |
-- |
65 (--) |
|
|
VSH-3 (South East Elevation) |
|
|
|
|
|
VSH-3 (South Elevation) |
|
|
|
|
|
VSH-4 |
|
|
|
|
|
VSH-5 |
|
|
|
|
|
VSH-6a |
|
|
|
|
|
VSH-7 |
|
|
|
|
NSR 21 |
VSH-3 (East Elevation) |
64 |
54 |
65 (55) |
|
|
VSH-3 (South East Elevation) |
|
|
|
|
|
VSH-3 (South Elevation) |
|
|
|
|
|
VSH-4 |
|
|
|
|
|
VSH-5 |
|
|
|
|
|
VSH-6a |
|
|
|
|
|
VSH-8 |
|
|
|
|
|
VSH-9 |
|
|
|
|
|
VSH-10 |
|
|
|
|
|
VSH-11 |
|
|
|
|
NSR 40a |
VSH-6a |
56 |
46 |
60 (50) |
|
|
VSH-6b |
|
|
|
|
|
VSH-7 |
|
|
|
|
NSR 40b |
VSH-1a |
58 |
48 |
60 (50) |
|
|
VSH-1a-1 |
|
|
|
|
|
VSH-1b |
|
|
|
|
|
VSH-2 |
|
|
|
|
|
VSH-3 (East Elevation) |
|
|
|
|
NSR 40c |
VSH-6a |
60 |
50 |
60 (50) |
|
|
VSH-6b |
|
|
|
|
|
VSH-7 |
|
|
|
|
NSR 45 |
VSH-3 (East Elevation) |
61 |
51 |
65 (55) |
|
|
VSH-3 (South East Elevation) |
|
|
|
|
|
VSH-3 (South Elevation) |
|
|
|
|
|
VSH-4 |
|
|
|
|
|
VSH-5 |
|
|
|
|
NSR 62 |
VSH-6a |
58 |
49 |
60 (50) |
|
|
VSH-8 |
|
|
|
|
|
VSH-9 |
|
|
|
|
|
VSH-10 |
|
|
|
|
|
VSH-11 |
|
|
|
|
NSR 28 |
VSW-1 (East Elevation) |
58 |
48 |
60 (50) |
|
|
VSW-1 (West Elevation) |
|
|
|
|
NSR 29a |
VSW-1 (East Elevation) |
55 |
45 |
60 (50) |
|
|
VSW-1 (West Elevation) |
|
|
|
|
NSR 46 |
VSW-1 (East Elevation) |
52 |
42 |
60 (50) |
|
|
VSW-1 (West Elevation) |
|
|
|
|
NSR 47 |
VSW-1 (East Elevation) |
58 |
48 |
60 (50) |
|
|
VSW-1 (West Elevation) |
|
|
|
|
NSR 48a |
VSW-1 (East Elevation) |
52 |
42 |
60 (50) |
|
|
VSW-1 (West Elevation) |
|
|
|
|
NSR 32 |
VSW-2 (North Elevation) |
57 |
47 |
60 (50) |
|
|
VSW-2 (West Elevation) |
|
|
|
|
NSR 53 |
VSW-2 (North Elevation) |
60 |
50 |
60 (50) |
|
|
VSW-2 (West Elevation) |
|
|
|
|
NSR 33 |
VSW-3 (North Elevation) |
56 |
48 |
60 (50) |
|
|
VSW-3 (East Elevation) |
|
|
|
|
|
VSW-4 (West Elevation) |
|
|
|
|
NSR 34b |
VSW-3 (North Elevation) |
58 |
-- |
60 (--) |
|
|
VSW-3 (East Elevation) |
|
|
|
|
NSR 49 |
VSW-3 (North Elevation) |
58 |
-- |
60 (--) |
|
|
VSW-3 (East Elevation) |
|
|
|
|
NSR 50 |
VSW-3 (North Elevation) |
55 |
48 |
60 (50) |
|
|
VSW-3 (East Elevation) |
|
|
|
|
|
VSW-4 (West Elevation) |
|
|
|
|
NSR 35a |
VSW-5a |
55 |
-- |
60 (--) |
|
|
VSW-5b |
|
|
|
|
NSR 35b |
VSW-5a |
55 |
-- |
60 (--) |
|
|
VSW-5b |
|
|
|
|
NSR 51a |
VSW-5a |
60 |
50 |
60 (50) |
|
|
VSW-5b |
|
|
|
7.10.2
Mitigation Measures
7.10.2.1
Provided the fixed plant are designed to meet the
maximum allowable SWLs as indicated in Table 7.12, no adverse noise impacts on the NSRs would be expected. However, it is still recommended that the
following good practice should be considered during detailed design:
· Louvers should be orientated away from adjacent NSRs whenever practicable;
· Adequate direct noise mitigation measures including silencers, acoustic louvers or acoustic enclosures should be adopted where necessary; and
· Quieter plant should be chosen as far as practical.
7.10.2.2
With proper implementation of the above noise
control measures, adverse operational noise impacts are not anticipated and residual
impacts are not predicted.
7.11.1.1
The assessment of construction noise has revealed that,
even with the application of all feasible direct mitigation measures and
scheduling of noisy construction works outside school examination periods, up
to seventeen representative NSRs will be affected by the implementation of the
project in excess of the stipulated standards. Residual impacts of between 1dB(A) to 8dB(A) are
predicted to occur.
7.11.1.2
The
7.11.1.3
The Caritas Bianchi College of Careers (NSR 20) is
predicted to be subject to the residual impacts during normal hours as a result
of the excavation works at HOM Station (WS15a).
Noise barriers and insulating fabric have been recommended as mitigation
measures to alleviate the noise emissions from PME. However, installation of substantial noise
barriers at the source of the exceedance (WS15a) would be impractical due to
site constraints as discussed in Section 7.9.2.9, as well as potential secondary impact as a
consequence of building a substantial noise barrier with a large footing. However, NSR 20 has been observed to have
been installed with either split-type or window-type air conditioners, which
will further alleviate the residual impacts.
Noisy construction works would also be avoided during the examination
periods.
7.11.1.4
The
7.11.1.5
For the two schools, (NSR 34 and NSR 35) where
exceedances are predicted during normal hours, residual impacts are predicted
during the construction of pipe pile and sheet pile cofferdam walls, rock
support and station structures at WHA Station east concourse. Due to the close proximity of the NSRs,
installation of substantial noise barriers would be impractical due to the lack
of space between the works sites and the pedestrian walkway at Tak On
Street. Both NSR 34 and NSR 35 are
observed to have been installed with either split-type or window-type air
conditioners, which will further alleviate the residual impacts. Noisy construction works would also be
avoided during the examination periods.
7.11.1.6
Seven residential NSRs, (NSR 18-1, NSR 18-7, NSR 28,
NSR 29, NSR 30, NSR 31c and NSR 32) will be exposed to residual impacts of 5dB(A)
or below, which is considered acceptable in view of the temporary nature of
construction phase impact and the construction works will be carried out
outside the sensitive hours, i.e. 7pm to 7am on Monday to Saturday and any time
on a general holiday, including Sunday.
7.11.1.7
The other five NSRs (NSR 27, NSR 33, NSR 48, NSR 50
and NSR 51) will be exposed to residual impacts of 6dB(A) to 8dB(A). All possible direct mitigation measures have
been applied for the reduction of noise levels from the corresponding works
sites and, therefore, they are considered exhaustive for the affected NSRs.
7.11.1.8
The magnitude of the residual impacts are assessed
in accordance with Section 4.4.3 of the EIAO-TM in Table 7.14 below.
Table 7.14: 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 1-8dB(A) could occur at up to 17 NSRs 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 50m from the KTE project
works area. |
|
Duration
and frequency of the adverse environmental impacts. |
The
construction noise impacts of the KTE project will be from
1 to 28 months and are, therefore, temporary and reversible. |
|
Likely
size of the community or the environment that may be affected by the adverse
impacts. |
About
5000 students (Assuming 1000 students for each of the 5 schools) and 800
dwellers (assuming 4 dwellers in each of the 200 residential units) would be
affected. In addition, pedestrians
within immediate vicinity will be temporarily affected. The size of the community can 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. |
Very
minimal as there would be no important cultural heritage resources in the
immediate vicinity of works sites |
|
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. |
7.11.1.9
Based upon the above, the following factors should
be considered in determining the residual impacts:
· The noise impacts are not predicted to significantly affect their health or cause loss of life;
· The predicted impacts are temporary and reversible;
· Impacts are localised and not of international and regional importance;
· The geographic extent of the adverse impacts is confined to small areas around the HMT and WHA works sites;
· The mitigation measures proposed will reduce the levels of impacts; and
· The study area has not shown itself to be fragile or undisturbed.
7.11.1.10
The MTR Corporation will facilitate communications
with the concerned parties with residual impacts during construction and review
to consider other initiatives, such as indirect technical remedies (ITR), if
required.
7.11.1.11
As such, the residual impacts associated with the construction
phase exceedances for the KTE would be considered minor and acceptable.
7.11.2
Operation
Phase
7.11.2.1
With the fixed plant designed to meet the SWL
requirements, adverse operational noise impacts are not anticipated.
7.12
Environmental Monitoring and Audit
7.12.1.1
The assessment has concluded that, despite the
implementation of the maximum practicable extent of mitigation measures,
residual impacts during the construction phase will occur as a result of the
implementation of the project. As such,
it is recommended that construction phase environmental monitoring and audit (EMA)
is undertaken to ensure that adverse impacts do not occur. It is noted that during the construction
process, episodes of noise higher levels may occur and it will be the function
of the EM&A process to identify these events and take the necessary action
such as, for example, temporarily adjustment of the number of plant to be used
or an equivalent measure as necessary. Further
details of the specific EM&A requirements are detailed in Section 13 of this report and in the EM&A Manual, together with event action
plans and procedures for complaints. The
procedure for complaints will include the provision of a hotline number for the
public to use when required.
7.13.1.1
Construction noise assessment has been
conducted. Results indicate that the
noise impacts after the implementation of all practical direct mitigation
measures would still exceed the stipulated noise criteria. Residual impacts have been assessed and
concluded to be temporary, reversible and unlikely to induce public health
concern and as such, are considered to be minor and acceptable.
7.13.1.2
For operation phase, it is anticipated that if the
construction contractor complies with the specified allowable sound power levels
from the respective louvers (which will be checked by the EM&A programme),
the operational noise impact at the sensitive receivers would be within
acceptable noise impact criteria.