6.1.1
General
6.1.1.1
The relevant legislation and associated guidance applicable
to present the study for the assessment of noise impacts include:
·
Noise Control Ordinance (NCO) (Cap. 400);
·
Environmental Impact Assessment Ordinance (EIAO) (Cap.
499);
·
Technical Memorandum (TM) on Noise from Construction Work
other than Percussive Piling (TM-GW);
·
TM on Noise from Percussive Piling (TM-PP); and
·
TM on Noise on Construction Work in Designated Areas
(TM-DA).
6.1.2
Construction Noise
6.1.2.1
The NCO provides the statutory framework for noise control
in Hong Kong. Assessment procedures and standards are set out in the respective
TM promulgated under the NCO.
6.1.2.2
To ensure a better environment, the TM-EIAO promulgated
under the EIAO has imposed more stringent criteria. For construction, there is
no statutory limit on daytime construction noise under the NCO and related TMs.
Nevertheless, the TM-EIAO stipulates criteria of 65 - 75dB(A) for daytime
construction activities, as shown in Table
6.1.
Table 6.1:
Noise standards for construction activities
|
Uses |
Noise Standards [1], Leq (30 mins) dB(A) |
|
0700 to 1900 hours on any day not being a Sunday or general holiday |
|
|
All domestic premises including temporary housing accommodation |
75 |
|
Hotels and hostels |
75 |
|
Educational institutions including kindergartens, nurseries and all
others where unaided voice communication is required |
70 65 (During
examinations) |
Notes:
[1] The above standards apply to
uses that rely on opened windows for ventilation.
Construction During
Normal Restricted Hours
6.1.2.3
The NCO also provides statutory control on general
construction works during restricted hours (ie 1900 to 0700 hours (of the next
day) from Monday to Saturday and at any time on Sundays or public holidays).
The use of Powered Mechanical Equipment (PME) for construction works during
restricted hours would require a Construction Noise Permit (CNP). The TM-GW
details the procedures adopted by EPD for assessing a CNP application. The
granting of a CNP is subject to conditions stated in the CNP and it may be revoked
at any time for failure to comply with the permit conditions.
6.1.2.4
In addition to the general controls on the use of PME
during restricted hours, the use of Specified Powered Mechanical Equipment
(SPME) and the undertaking of Prescribed Construction Work (PCW) during the
restricted hours in a designated area are controlled by the TM-DA. Construction
plant or equipment classified as SPME under the TM-DA includes hand-held
breakers, bulldozers, concrete mixer lorries, dump trucks and poker vibrators.
The PCW includes the erection or dismantling of formwork or scaffolding,
hammering, handling of rubble, wooden boards, steel bars, or scaffolding
material, and the disposal of rubble through plastic chutes.
6.1.2.5
The TM-DA details the procedures that should generally be
adopted by the Noise Control Authority for assessing the use of SPME during
restricted hours and for determining whether a CNP would be issued.
6.1.2.6
Maximum noise levels from construction activities during
restricted hours at affected Noise Sensitive Receivers (NSRs) are controlled
under the TMs and shall not exceed the specified Acceptable Noise Levels
(ANLs). These ANLs are stipulated in accordance with the Area Sensitivity
Ratings (ASR) established for the NSRs. The ANLs for construction works in
Designated Areas are more stringent than those given in the TM-GW and are
summarised in Table 6.2.
Table 6.2: ANLs for construction during restricted hours
Time Period |
Acceptable Noise Levels for Area
Sensitivity Ratings, dB(A) |
||
|
A |
B |
C |
|
|
All weekdays during the evening (1900 to 2300 hours), and general holidays (including Sundays) during the day and evening (0700 to 2300 hours) |
60 (45) |
65 (50) |
70 (55) |
|
All days during the night-time (2300 to 0700 hours) |
45 (30) |
50 (35) |
55 (40) |
Note: Figures in brackets are
ANLs for SPME construction work in designated areas
6.1.2.7
Despite any description made in the report, 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 making a decision
in granting a CNP. Nothing in the report shall bind the Noise Control Authority
in making a decision. If a CNP is to be issued, the Noise Control Authority
shall include any conditions it may demand. Failure to comply with any such
conditions will lead to cancellation of the CNP and prosecution under the NCO.
Percussive Pilling
6.1.2.8
Under the
TM-PP, CNPs are also required for percussive piling involving the use of
diesel, pneumatic and / or steam hammer. This TM specifies the permitted hours
and other conditions for percussive piling. Table 6.3 lists the acceptable percussive piling noise levels for
various types of NSR.
Table 6.3: ANLs for percussive piling
|
NSR Window Type or Means of Ventilation |
ANL,
dB(A) |
|
(i) NSR (or part of NSR) with no window or other opening |
100 |
|
(ii) NSR with central air conditioning system. |
90 |
|
(iii) NSR with windows or other openings but without central air conditioning system |
85 |
6.1.2.9
Depending on the number and type of piling machines and the
separation distance from NSRs, percussive piling may be restricted to 12, 5 or
3 hours per day. For NSRs that are particularly sensitive to noise, such as
hospitals, medical clinics, educational institutions and courts of law, a
further reduction of 10 dB(A) shall be applied to the above ANLs.
6.1.2.10
To minimize the construction noise impact, alternative
construction methods to replace percussive piling and blasting shall be
proposed as far as practicable.
6.1.3
Operational Noise
6.1.3.1
The TM-EIAO stipulates the noise standards for road traffic
noise source as shown in Table 6.4.
Table 6.4: Noise standards
for operational phase
|
Common Uses |
Noise
Standards [1] |
|
Road Traffic
Noise L10
(1hour) dB(A) |
|
|
All domestic
premises including temporary housing accommodation |
70 |
|
Hotels and
hostels |
70 |
|
Offices |
70 |
|
Educational
institutions including kindergartens, nurseries and all others where unaided
voice communication is required |
65 |
|
Places of
public worship and courts of law |
65 |
|
Hospitals,
clinics, convalescences and homes for the aged, diagnostic rooms, wards |
55 |
Notes:
[1]
The above standards apply to uses that
rely on opened windows for ventilation.
6.2
Description of Existing Environment
6.2.1.1
Representative NSRs in the vicinity are within the TKO Area
86 development. Hence, the existing ambient noise climate is dominated by road
traffic from the nearby Wan Po Road and Wan O Road.
6.3
Noise Sensitive Receivers & Pollution Sources
6.3.1
Sensitive Receivers
6.3.1.1
With reference to Annex 13 of the TM-EIAO, the potential
NSRs could be, but not limited to the following: residential uses (all domestic
premises including temporary housing), institutional uses (educational
institutions including kindergarten and nurseries, hospitals, medical clinics,
homes for the aged, convalescent homes, places of public worship, libraries,
courts of law, performing arts centres, auditoria and amphitheatres), and
others (country parks and hostels).
6.3.1.2
Representative NSRs within the assessment area (a distance
of 300m from the project boundary) have been identified. The first layer NSRs
have been selected for assessment. These NSRs include both the existing and
planned sensitive receivers.
6.3.1.3
The existing NSRs have been identified by means of
topographic maps, aerial photos, land status plans and several site surveys.
Planned / committed NSRs have been identified by making reference to relevant
Outline Zoning Plans, Outline Development Plans, Layout Plans and other
relevant published land use plans, including plans and drawings published by
Lands Department and any land use and development applications approved by the
Town Planning Board.
6.3.1.4
The representative existing and planned NSRs in the
vicinity are summarized in Table 6.5. The locations of NSRs are
illustrated in Drawing no.
209506/EIA/NS/001.
6.3.1.5
According to “MTR Tseung Kwan O Line, Tseung Kwan O LOHAS
Park CDA – Class B Amendments To The Approved Master Layout Plan”, the TKO Area
86 development will include three stages: Stage 1 (2005-2018); Stage 2
(2008-2019) and Stage 3 (2011-2020). Please refer to Drawing no. 209506/EIA/NS/001 for the demarcation.
Table 6.5: Locations of representative noise sensitive receivers
|
NSR No. |
Description |
Landuse |
No. of Storeys |
Type of Assessment |
|
|
Construction |
Operation |
||||
|
Existing |
|
|
|
||
|
R2 |
Lohas Park, Le Prestige, Tower 1 (South facade) |
Residential |
49 |
√ |
√ |
|
R3 |
Lohas Park, Le Prestige, Tower 2 (Southwest facade) |
Residential |
54 |
- [2] |
√ |
|
Planned |
|
|
|
||
|
R1 |
Lohas Park Stage 1(Planned Development in Area 86, Package 2) (South facade) |
Residential |
55 |
√ |
- [2] |
|
R6 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 6) (Southeast facade) |
Residential |
46 |
√ |
√ |
|
R7 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 6) (Southwest facade) |
Residential |
46 |
- [2] |
√ |
|
R8 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 6) (South facade) |
Residential |
46 |
√ |
√ |
|
R9 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 6) (South facade) |
Residential |
49 |
√ |
√ |
|
R10 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 6) (South facade) |
Residential |
55 |
√ |
√ |
|
R12 |
Lohas Park Stage 1(Planned Development in Area 86, Package 5) (Southeast facade) |
Residential |
55 |
√ |
√ |
|
R13 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 5) (Southwest facade) |
Residential |
55 |
- [2] |
√ |
|
R14 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 5) (Southeast facade) |
Residential |
55 |
√ |
√ |
|
R15 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 5) (Southwest facade) |
Residential |
55 |
- [2] |
√ |
|
R16 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 5) (South facade) |
Residential |
57 |
√ |
√ |
|
R17 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 5) (Southwest facade) |
Residential |
57 |
- [2] |
√ |
|
R18 |
Lohas Park Stage 1 (Planned Development in Area 86, Package 5) (Southwest facade) |
Residential |
57 |
√ |
√ |
|
R22 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (Southeast facade) |
Residential |
56 |
√ |
√ |
|
R23 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (Southeast facade) |
Residential |
56 |
√ |
√ |
|
R24 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (Southeast facade) |
Residential |
56 |
√ |
√ |
|
R25 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (Southeast facade) |
Residential |
52 |
√ |
√ |
|
R26 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (Southwest facade) |
Residential |
49 |
- [2] |
√ |
|
R27 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (West facade) |
Residential |
49 |
√ |
√ |
|
R28 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (Northwest facade) |
Residential |
49 |
- [2] |
√ |
|
R29 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 10) (Southwest facade) |
Residential |
55 |
√ |
√ |
|
R30 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 10) (Southwest facade) |
Residential |
55 |
- [2] |
√ |
|
R31 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 10) (Southwest facade) |
Residential |
49 |
- [2] |
√ |
|
R32 |
Lohas Park Stage 3 (Planned Development in Area 86,Package 10) (West facade) |
Residential |
55 |
√ |
√ |
|
R33 |
Planned Primary School & Secondary School near Wan Po Road (Southwest facade) |
Educational |
5[1] |
√ |
√ |
|
R34 |
Planned Primary and Secondary Schools (South facade) |
Educational |
5[1] |
√ |
- [2] |
Note: [1] All planned schools are
assumed to have 5 storeys.
[2] Representative sensitive receivers have been
selected. Hence, they are not selected for the assessment.
6.3.1.7
These at receiver mitigation measures were proposed for
noise sensitive receivers that face the junction of Road R5 and Road D9. It was
recognized at the time of planning of Lohas Park that a discontinuity in noise
barriers to be provided alongside Road D9 would be unavoidable due to the road
junction.
6.3.1.8
It was assumed at the time of planning Lohas Park that the
Road D9 noise barriers would be cantilevered structures beside the carriage
ways.
6.3.1.9
Inevitably, the location of noise barriers alongside Road
D9 would have to accommodate traffic engineering and sight line requirements in
order for the road junctions to operate safely for pedestrians and road users.
Accordingly, the CBL project would need to provide the same or equivalent
performing noise mitigation measures to those assumed by the Area 86 Lohas Park
proponent.
6.4
Potential Concurrent Projects
6.4.1.1
The potential concurrent projects in the vicinity of the
CBL project and their program are shown in Table 6.6.
Table 6.6: Potential concurrent projects and their program
|
Concurrent Project |
Construction Program |
|
TKO-LT
Tunnel |
2017 - 2020 |
|
Hong Kong
Offshore Wind Farm in Southeastern Waters |
[j1] Early of 2017 – Late of 2017 |
|
TKO
Area 86 Development |
|
|
Stage
1 |
Early
of 2005 – End of 2018 |
|
Stage
2 |
Mid of
2008 – End of 2019 |
|
Stage
3 |
Late
of 2011 – End of 2020 |
|
TKO Area 85
Residential Development |
[1] |
|
RTHK Development
of New Broadcasting House |
[2] |
Note:
[1] The distance from
the site boundary of CBL to TKO Area 85 is greater than 300m. Hence the
cumulative impact is not taken into account.
[2] The project is undergoing the procedure of
application and has not been approved yet.
6.4.1.2
The distances from the closest work sites of TKO-LT Tunnel
and HK Offshore Wind Farm in Southeastern Waters to the representative NSRs are
1000m and 750m respectively. Hence, their cumulative impacts have not been
taken into account. However, cumulative impact due to the construction of TKO
Area 86 Lohas Park Development has been included.
6.4.1.3
The TKO Area 85 Residential Development is still undergoing
the procedures of Broad Development Parameters of the Applied Use /Development.
The distances from the centre of the site to the CBL will be more than 300m.
Therefore, the cumulative noise impact is not anticipated.
6.4.1.4
Area 137 and a presently vacant site on the southern side
of Road D9, adjacent to Wan Po Road, will be used as temporary work sites for
temporary material stockpiling. As Area 137 is 300m away from the NSRs and
there is no evening and night-time work due to CBL construction, the
construction noise impact from area 137 is not included in the construction
noise assessment.
6.4.1.5
The New Broadcasting House of RTHK is presently undergoing
the technical feasibility study. The location and construction programme of the
site are not yet approved. Hence, the construction noise impact from RTHK
Development is not included in the construction noise assessment. Furthermore,
according to Architectural Services Department, centralized air conditioning
system will be provided to the building, and therefore the building would not
be noise sensitive during the operational phase of CBL. Since the New
Broadcasting House will be equipped with centralized air conditioning system,
no further actions are required by the CBL project proponent.
6.5.1
Construction Phase
6.5.1.1
Assessment Procedures
6.5.1.2
Construction
noise assessment will be conducted based on the following procedures:
·
Determine the assessment area;
·
Identify and locate representative NSRs that may be
affected by the works;
·
Identify the construction method and work sequence
for the construction period;
·
Identify the construction plant inventory for each
corresponding construction work sequence;
·
Determine the sound power levels of the plant items
according to the information stated in the TM-GW or other recognised sources of
reference, where appropriate;
·
Apply corrections for facade, distance, barrier
attenuation, acoustic reflection where applicable;
·
Predict construction noise levels at the NSRs;
·
Quantify the level of impact at the NSRs, in
accordance with TM-GW; and
·
Predict the cumulative noise impacts for any
concurrent construction works in the vicinity of the proposed work.
6.5.1.3
Noise Assessment Tool
6.5.1.4
An in-house
program has been used for construction noise calculations. Initially, program
runs were conducted without mitigation measures (i.e. the “Unmitigated
Scenario”). Should exceedence be identified, further runs would be made with
mitigation measures incorporated (i.e. the “Mitigated Scenario).
6.5.2
Operational Phase
6.5.2.1
Road Traffic Noise
6.5.2.3
The computer
programme, RoadNoise 2000, has been used to model traffic noise from road
networks. It complies with the
Calculation of Road Traffic Noise (CRTN) developed by the UK Department of
Transport.
6.5.2.4
According to the
EIA Study Brief, calculations of future road traffic noise will be based on the
peak hourly flow for the maximum traffic projected within a 15 years period
upon commencement of operation. The
traffic projection will take into account the induced traffic due to the
operation of other planned roads and committed projects. Since the commencement year for CBL is Year
2021, the assessment year for road traffic noise is taken at Year 2036.
6.6
Construction Noise Assessment
6.6.1
Tentative Construction Programme
6.6.1.1
The tentative
construction programmes showing the construction period of CBL and road D9 are
shown in Appendix 4.1.
6.6.2
Construction Noise Source
6.6.2.1
The major
construction works for CBL would include the following activities:
· Install piles by marine piling rigs;
· Erect cofferdam;
· Build pile caps;
· Build piers
· Erect concrete deck segments of the approach; and
· Install main bridge & side spans.
6.6.2.2
The major
construction works for Road D9 would include the following activities:
· Install sheet piles along the sea wall and pump out the water;
· Excavate the soil behind the seawall;
· Strengthen/expand the existing seawall;
· Backfill the excavated soil;
· Ground improvement by compaction grouting;
· Piling for noise barrier; and
· Noise barrier erection
6.6.2.3
These
construction activities will involve the use of Powered Mechanical Equipment
(PME) including air compressor, excavators, lorries, mobile cranes, concrete
lorry mixers, pokers, rollers, etc. The types of PME adopted are listed in Table
6.7 and Appendix 6.2.
6.6.2.4
The utilization
rates, which have been reviewed by the
Project Engineer, are also presented in Table
6.7 and Appendix 6.2. In practice, the PME will not be operating at all times
within a work site. However, the following construction noise assessment will demonstrate a worst
case scenario. The construction plant
inventory used in the assessment has been confirmed to be representative of the
works by the project proponent.
Table 6.7: PMEs and their utilization rates
|
PME |
Typical Utilisation Rate (%) |
|
Air Compressor (CNP003) |
100% |
|
Asphalt Paver (CNP004) |
100% |
|
Bar Bender and Cutter (CNP021) |
100% |
|
Hand-held breaker (CNP026) |
100% |
|
Break (Pneumatic) (CNP027) |
100% |
|
Breaker, Excavator Mounted (Hydraulic) (CNP028) |
100% |
|
Bulldozer (CNP030) |
100% |
|
Concrete Mixer (CNP045) |
70% |
|
Concrete Lorry Mixer (CNP044) |
70% |
|
Concrete Pump (CNP047) |
100% |
|
Crane Mobile (CNP048) |
100% |
|
Tower Crane (CNP050) |
100% |
|
Compactor, vibratory (CNP050) |
100% |
|
Cutter, Circular, Steel (CNP056) |
100% |
|
Crane Barge (CNP061) |
100% |
|
Dump Barge (CNP061) |
100% |
|
Derrick Barge (CNP061) |
100% |
|
Grab dredger (CNP063) |
100% |
|
Dump Truck (CNP067) |
70% |
|
Drill, Hand-Held (Battery) (CNP071) |
100% |
|
Excavator/Loader, Wheeled/Tracker (CNP081) |
100% |
|
Backactor (CNP081) |
100% |
|
Mini Backhoe (CNP082) |
100% |
|
Generator, silenced (CNP103) |
100% |
|
Grout Pump (CNP106) |
100% |
|
Welder/Generator, portable (CNP107) |
100% |
|
Lorry (CNP141) |
70% |
|
Paint Line Marker (CNP161) |
100% |
|
Piling, Large Diameter Bored, Grab and Chisel (CNP164) |
100% |
|
Piling, Large Diameter Bored, reverse circulation drill (CNP166) |
100% |
|
Piling rig and drilling rig (CNP167) |
100% |
|
Poker, Vibratory, Hand-held (CNP170) |
100% |
|
Piling, Vibrating Hammer (CNP172) |
100% |
|
Roller (CNP185) |
100% |
|
Tug boat (CNP221) |
100% |
|
Water Pump (CNP281) |
100% |
|
Crane Truck (CNP144) |
100% |
6.6.3
Assessment Results (Unmitigated Scenario)
6.6.3.1
According to the
latest engineering design, construction works would mainly comprise the
activities as described in Section 6.6.2. The corresponding SWLs of these activities have been
predicted according to the SWLs of the PME and the assessment methodology
listed in TM-GW. Appendix 6.3 lists the
plant inventory adopted for each workfront and Appendix 6.4 illustrates the distances between the notional sources and
the NSRs.
6.6.3.2
Appendix 6.5 presents the monthly unmitigated noise level contributed by
different workfronts of CBL during construction period at the representative
NSRs and Appendix 6.6 presents
the calculated construction noise impacts. The predicted construction noise
impacts of CBL at the NSRs under unmitigated scenario are summarised in Table
6.8 below.
Table 6.8: Predicted construction noise impact at
NSRs under unmitigated scenario
|
NSR
No. |
Description |
Landuse |
Criterion,
dB(A) [1] |
Unmitigated
Noise Level dB(A) [2] |
Exceedance,
dB(A) |
|
Existing |
|||||
|
R2 |
Lohas Park, Le Prestige, Tower 1 (South facade) |
Residential |
75 |
77 |
2 |
|
Planned |
|||||
|
R1 |
Lohas Park Stage 1(Planned Development in
Area 86, Package 2) (South facade) |
Residential |
75 |
68 |
- |
|
R6 |
Lohas Park Stage 1 (Planned Development in Area 86, Package
6) (Southeast facade) |
Residential |
75 |
82 |
7 |
|
R8 |
Lohas Park Stage 1 (Planned Development in Area 86,
Package 6) (South facade) |
Residential |
75 |
81 |
6 |
|
R9 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 6) (South facade) |
Residential |
75 |
82 |
7 |
|
R10 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 6) (South facade) |
Residential |
75 |
83 |
8 |
|
R12 |
Lohas Park Stage 1(Planned Development in
Area 86, Package 5) (Southeast facade) |
Residential |
75 |
89 |
14 |
|
R14 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (Southeast facade) |
Residential |
75 |
91 |
16 |
|
R16 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (South facade) |
Residential |
75 |
88 |
13 |
|
R18 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (Southwest facade) |
Residential |
75 |
85 |
10 |
|
R22 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
82 |
7 |
|
R23 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
85 |
10 |
|
R24 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
88 |
13 |
|
R25 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
89 |
14 |
|
R27 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (West facade) |
Residential |
75 |
89 |
14 |
|
R29 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 10) (Southwest facade) |
Residential |
75 |
87 |
12 |
|
R32 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 10) (West facade) |
Residential |
75 |
78 |
3 |
|
R33 |
Planned Primary School & Secondary
School near Wan Po Road (Southwest facade) |
Educational |
70 (65) [1] |
79 |
9(14) |
|
R34 |
Planned Primary and Secondary Schools
(South facade) |
Educational |
70 (65) [1] |
77 |
7 (12) |
Note:
[1] Values in parentheses indicate the noise
criterion during examination period of educational institution.
[2] Bolded values mean exceedence of the noise
criteria
6.6.3.3
As shown in above
table, the predicted unmitigated construction noise levels at most residential receivers,
except Lohas Park Stage 1 (R1), will exceed the noise criteria by 2-16 dB(A)
and in the range of 68 – 91 dB(A).
6.6.3.4
For educational
institutions, the predicted unmitigated
construction noise levels will exceed the normal
period noise criterion and examination period noise criterion by 7-9 dB(A)
and 12-14 dB(A) respectively and in the
range of 77 – 79 dB(A).
6.6.4
Mitigation Measures
6.6.4.1
Unmitigated
construction noise would exceed the daytime noise criteria. Mitigation measures are therefore
required. The following mitigation
measures have been considered:
· Good site practices to limit noise emissions at the source;
· Use of quiet plant and working methods;
· Use of site hoarding as noise barrier to screen noise at ground level of NSRs;
· Use of shrouds / temporary noise barriers to screen noise from relatively static PMEs;
· Scheduling of construction works outside school examination periods in critical area; and
· Alternative use of plant items within one worksite, wherever practicable.
6.6.4.2
Detailed descriptions of these mitigation measures are
given in the following sections.
Good Site
Practice and Noise Management techniques
6.6.4.3
Good site practice and noise management techniques could
considerably reduce the noise impact from construction site activities on
nearby NSRs. The following measures
should be followed during each phase of construction:
· Only well-maintained plant should be operated on-site and the plant should be serviced regularly during the construction programme;
· Machines and plant (such as trucks, cranes) that are in intermittent use should be shut down between work periods or should be throttled down to a minimum;
· Plant known to emit noise strongly in one direction, where possible, should be orientated so that the noise is directed away from nearby NSRs;
· Silencers or mufflers on construction equipment should be properly fitted and maintained during the construction works;
· Mobile plant should be sited as far away from NSRs as possible and practicable; and
· Material stockpiles, site office and other structures should be effectively utilised, where practicable, to screen noise from on-site construction activities.
6.6.4.4
The benefits of these techniques can vary according to
specific site conditions and operations.
The environmental noise climate would certainly be improved through
these control practices, although the improvement can only be quantified during
implementation when specific site parameters are known. The assessment has therefore not taken into
account the effectiveness of Good Site Practices and Noise Management
Techniques.
Quiet Plant and Working Methods
6.6.4.5
The use of quiet plant is a feasible solution to tackle
adverse noise impacts associated with construction works. It is generally known
(supported by field measurement) that particular models of construction
equipment are quieter than standard types given in the TM-GW. Whilst it is
generally considered too restrictive to specify that the Contractor has to use
specific models or items of plant, it is reasonable and practicable to set
plant noise performance specifications for specific PME so that more
flexibility is allowed. A pragmatic approach would be to request that the
Contractor should independently verify the noise level of the plant proposed to
be used and demonstrate through furnishing of these results, that the plant
proposed to be used on the site meets the requirements.
6.6.4.6
The use of quiet plant associated with the construction
works is prescribed in British Standard “Noise Control on Construction and Open
Sites, BS5228: Part 1: 2009” which contains the SWLs for specific quiet PME.
Use of site hoarding
6.6.4.7
Purposed built temporary noise barriers (approx 2.4m high)
located at the site boundaries between noisy construction activities and NSRs
could generally reduce noise levels at lower height NSRs through partial
screening. In general, this would provide a minimum 5 dB(A) attenuation for the
low level receivers. It would be possible for the Contractor to provide these
in the form of site hoardings to achieve this attenuation effect, provided that
the hoardings have no openings or gaps and have a superficial surface density
of at least 14kg/m2. Good site practice shall also be adopted by the
Contractor to ensure that the conditions of the hoardings are properly
maintained throughout the construction period. As a conservative approach,
however, site hoarding has not been taken into consideration in the
construction noise assessment.
Use of Temporary or Movable
Noise Barriers and Full Enclosure for Relatively Fixed Plant source
6.6.4.8
Movable temporary noise barriers that can be located close
to noisy plant and be moved concurrently with the plant along a worksite can be
very effective for screening noise from NSRs. A typical design which has been
used locally is a wooden framed barrier with a small-cantilevered upper portion
of superficial density no less than 14kg/m2 on a skid footing with
25mm thick internal sound absorptive lining. This measure is particularly
effective for low level zone of NSRs. A cantilevered top cover would be
required to achieve screening benefits at upper floors of NSRs.
6.6.4.9
Movable barriers will be used for some PME (e.g. pipe pile
rigs, auger). It is anticipated that suitably designed barriers could achieve
at least 5dB(A) reduction for movable plant and 10dB(A) for stationary plant.
6.6.4.10
The use of standard enclosure has been considered in this
assessment to shelter relatively fixed plant including air compressor,
generator, etc. These standard enclosures can provide about 15dB(A) noise reduction. For horizontal jack, movable noise barriers
of 5dB(A) attenuation have been assumed.
6.6.4.11
A summary of the barriers and standard enclosures adopted
for various PMEs and the indicative drawings are shown in Appendix 6.7. Their associated noise reductions are given in Appendix 6.2.
6.6.5
Assessment Results (Mitigated Scenario)
6.6.5.1
With the implementation of the above mentioned mitigation
measures, the predicted mitigated construction noise levels at representative
NSRs are presented in Table 6.9. Appendix 6.8 presents
the monthly mitigated noise contribution from different work fronts during the
construction period and Appendix
6.9 presents the
combined mitigated construction noise impacts on representative NSRs.
Table 6.9: Predicted construction noise impact on NSRs
under mitigated scenario
|
NSR
No. |
Description |
Landuse |
Criteria,
dB(A) [1] |
Mitigated
Noise Level dB(A) |
Exceedance,
dB(A) |
|
Existing |
|
||||
|
R2 |
Lohas Park, Le Prestige, Tower 1 (South facade) |
Residential |
75 |
63 |
- |
|
Planned |
|
||||
|
R1 |
Lohas Park Stage 1(Planned Development in
Area 86, Package 2) (South facade) |
Residential |
75 |
54 |
- |
|
R6 |
Lohas Park Stage 1 (Planned Development in Area 86,
Package 6) (Southeast facade) |
Residential |
75 |
67 |
- |
|
R8 |
Lohas Park Stage 1 (Planned Development in Area 86,
Package 6) (South facade) |
Residential |
75 |
65 |
- |
|
R9 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 6) (South facade) |
Residential |
75 |
66 |
- |
|
R10 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 6) (South facade) |
Residential |
75 |
67 |
- |
|
R12 |
Lohas Park Stage 1(Planned Development in
Area 86, Package 5) (Southeast facade) |
Residential |
75 |
73 |
- |
|
R14 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (Southeast facade) |
Residential |
75 |
74 |
- |
|
R16 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (South facade) |
Residential |
75 |
72 |
- |
|
R18 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (Southwest facade) |
Residential |
75 |
69 |
- |
|
R22 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
66 |
- |
|
R23 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
69 |
- |
|
R24 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
Residential |
75 |
72 |
- |
|
R25 |
Lohas Park Stage 3 (Planned Development in
Area 86,Package 11) (Southeast facade) |
Residential |
75 |
73 |
- |
|
R27 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (West facade) |
Residential |
75 |
73 |
- |
|
R29 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 10) (Southwest facade) |
Residential |
75 |
71 |
- |
|
R32 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 10) (West facade) |
Residential |
75 |
62 |
- |
|
R33 |
Planned Primary School & Secondary
School near Wan Po Road (Southwest facade) |
Educational |
70 (65)[1] |
65 |
- |
|
R34 |
Planned Primary and Secondary Schools
(South facade) |
Educational |
70 (65)[1] |
62 |
- |
Note:
[1] Values in parentheses indicate the noise criterion during
examination period of educational institution.
6.6.5.2
As shown in above table, the predicted mitigated
construction noise levels at all the residential NSRs would comply with the
criterion of 75 dB(A) and in the range of 54 – 74dB(A).
6.6.5.3
For educational institution, the predicted mitigated
construction noise levels would comply with the criterion during normal period
and examination period respectively. The predicted noise levels at the
educational institutions would be in the range of 62 – 65 dB(A).
6.6.6
Cumulative Impacts
6.6.6.1
Potential concurrent projects will include the TKO Area 86
development. For the development programme of TKO Area 86 Development, reference was made to “MTR
Tseung Kwan O Line, Tseung Kwan O LOHAS Park CDA – Amendments To The Approved
Master Layout Plan”. As the construction plant inventory for TKO Area 86
Development was not available, the plant inventory was determined according to
EIA-144/2008 “Proposed Comprehensive Development at Wo Shang Wai, Yuen Long”.
The plant inventory for the substructure and superstructure construction activities
in that study have been adopted as a reasonable similar prediction of noise
impacts due the construction of TKO Area 86 Development. Table 6.10 summarises the predicted cumulative noise level at
representative NSRs. Appendix
6.10 presents the
monthly mitigated noise contribution from different work fronts and concurrent
projects on representative NSRs. Appendix
6.11 presents the
predicted cumulative construction noise impacts. A sample calculation of the
predicted sound pressure level at an NSR on a monthly basis is presented in Appendix 6.12.
Table
6.10: Cumulative noise impact on representative NSRs
|
NSR No. |
Description |
Construction Noise Contribution dB(A) |
Criteria [1] dB(A) |
Total [2] dB(A) |
Exceedance dB(A) |
Duration of Exceedence Months |
|||
|
LOHAS Park |
CBL |
||||||||
|
Stage 1 (S10) |
Stage 2 (S11) |
Stage 3 (S12) |
|||||||
|
Existing |
|||||||||
|
R2 |
Lohas Park, Le Prestige, Tower 1 (South facade) |
65 |
- [4] |
- [3] |
63 |
75 |
67 |
- |
- |
|
Planned |
|||||||||
|
R1 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 2) (South facade) |
59 |
58 |
- [3] |
54 |
75 |
62 |
- |
- |
|
R6 |
Lohas Park Stage 1 (Planned Development in Area 86,
Package 6) (Southeast facade) |
- [5] |
- [4] |
- [3] |
67 |
75 |
67 |
- |
- |
|
R8 |
Lohas Park Stage 1 (Planned Development in Area 86,
Package 6) (South facade) |
- [5] |
- [4] |
55 |
65 |
75 |
65 |
- |
- |
|
R9 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 6) (South facade) |
- [5] |
- [4] |
- [4] |
66 |
75 |
66 |
- |
- |
|
R10 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 6) (South facade) |
- [5] |
- [4] |
- [4] |
67 |
75 |
67 |
- |
- |
|
R12 |
Lohas Park Stage 1(Planned Development in
Area 86, Package 5) (Southeast facade) |
- [5] |
- [4] |
- [4] |
73 |
75 |
73 |
- |
- |
|
R14 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (Southeast facade) |
- [5] |
- [4] |
- [4] |
74 |
75 |
74 |
- |
- |
|
R16 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (South facade) |
- [5] |
- [4] |
- [4] |
72 |
75 |
72 |
- |
- |
|
R18 |
Lohas Park Stage 1 (Planned Development
in Area 86, Package 5) (Southwest facade) |
- [5] |
- [4] |
- [4] |
69 |
75 |
69 |
- |
- |
|
R22 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
68 |
- [4] |
- [5] |
66 |
75 |
69 |
- |
- |
|
R23 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
68 |
- [4] |
- [5] |
69 |
75 |
71 |
- |
- |
|
R24 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
66 |
- [4] |
- [5] |
72 |
75 |
72 |
- |
- |
|
R25 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (Southeast facade) |
62 |
- [4] |
- [5] |
73 |
75 |
74 |
- |
- |
|
R27 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 11) (West facade) |
- [5] |
- [4] |
- [5] |
73 |
75 |
73 |
- |
- |
|
R29 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 10) (Southwest facade) |
- [4] |
- [4] |
- [5] |
71 |
75 |
71 |
- |
- |
|
R32 |
Lohas Park Stage 3 (Planned Development
in Area 86,Package 10) (West facade) |
- [3] |
- [4] |
- [5] |
62 |
75 |
62 |
- |
- |
|
R33 |
Planned Primary School & Secondary
School near Wan Po Road (Southwest facade) |
- [5] |
- [4] |
- [4] |
65 |
70 (65) [1] |
66 |
- (1) |
0(4) |
|
R34 |
Planned Primary and Secondary Schools
(South facade) |
66 |
- [4] |
- [5] |
62 |
70 (65) [1] |
67 |
- (2) |
0(46) |
Notes:
[1] Values in parentheses indicate the exceedence
during examination period of educational institution.
[2] Cumulative impacts arisen from TKO Area
86 Development and CBL are included.
[3] The notional source is out of 300m of the
assessment area.
[4] The notional source is located behind of the
assessment point.
[5] Buildings have been erected and no
construction in this area.
6.6.6.2
As shown in the above table, the predicted noise levels at
all the residential NSRs would comply with the criterion of 75 dB(A) and in the
range of 62 – 74dB(A).
6.6.6.3
For educational
institutions, the predicted noise levels would comply with the criterion of 70
dB(A) during normal period and in the range of 66 – 67dB(A). However, 1 – 2
dB(A) exceedence of the 65 dB(A) criterion and the duration of exceedences
ranges from 4 – 46 months during examination period is predicted at the Planned
Primary and Secondary School (R33 & R34). Typical examination period includes May,
June, November and December, so the anticipated duration is approximately 16
months. In addition, examination period should only last for 2 weeks. The intake year for the Planned Primary and Secondary
School (R33 & R34) and the construction programme for Lohas Park
Stage 1, Stage 2 and Stage 3 are not yet confirmed. The predicted exceedance
and duration of exccedance is a conservative estimate as the current cumulative assessment has assumed the construction period
of Lohas Park will be continuous throughout the construction of CBL.
6.6.6.4
The contractor will be required further confirm the construction programme of R33
& R34 at the commencement of the construction of CBL work. The CBL
construction work at Road D9 will be scheduled to avoid the examination period
at the Planned Primary and Secondary Schools if they are open (R33 & R34) during CBL construction work.
6.7
Road Traffic Noise Assessment
6.7.1
Traffic Flow
6.7.1.1
Major roads in the vicinity of the Study Boundary include
CBL, D9 Road, Wan Po Road and Road R5 within the Lohas Park Area 86 development.
The general layout plan and Study Boundary are shown in the Drawing no. 209506/EIA/IN/001. The traffic data have been
approved by Transport Department in 2012 and 2013 (Appendix 6.13a). Computer plots of the road scheme and key to traffic
flow ID are shown in Appendix
6.13b. Table 6.11 shows
the traffic data in 2036.
Table 6.11: Peak hour traffic flow data in 2036
|
ID[1] |
Road Section |
Peak Hour Flow (veh/h) |
% Heavy Vehicle |
Design Speed (km/h) |
|
11 |
Wan Po Road
(NB) |
853 |
58.4 |
70 |
|
12 |
Wan Po Road
(SB) |
1381 |
37.5 |
70 |
|
13 |
Road D9 (EB) |
1137 |
34.6 |
50 |
|
14 |
Road D9 (WB) |
871 |
35.1 |
50 |
|
15 |
Wan Po Road
(NB) |
336 |
55.8 |
70 |
|
16 |
Wan Po Road
(SB) |
598 |
38.6 |
70 |
|
18 |
Road D9 (WB) |
1846 |
29.4 |
80 |
|
19 |
Road D9 (EB) |
1394 |
33.9 |
50 |
|
20 |
Road D9 (WB) |
1846 |
29.4 |
50 |
|
115 |
CBL (EB) |
1394 |
33.9 |
80 |
|
116 |
CBL (WB) |
1846 |
29.4 |
80 |
|
243 |
Road R5 (NB) |
202 |
5.0 |
50 |
|
244 |
Road R5 (SB) |
269 |
5.0 |
50 |
Notes:
[1] No ID17 in the flow ID
6.7.2
Assessment Results (Unmitigated Scenario)
6.7.2.1
The predicted road traffic noise levels at the
representative NSRs and the road traffic noise levels during the without
project scenario are summarized in Table
6.12. Detailed
noise impacts of unmitigated scenario and without CBL scenario (at Year 2036,
15 years after opening and at Year 2015, before the commencement of works to
construct the road) on different levels of the NSRs are given in Appendix 6.14 and Appendix
6.15. Sample
calculation is given in Appendix
6.16a.
Table 6.12: Predicted road traffic noise impact on
representative NSRs (Year 2036)
|
NSR No. |
Landuse |
Max Noise Level, dB(A) |
Criterion, dB(A) |
Compliance (Y/N) |
Without CBL Noise Impact, dB(A) |
|
Existing |
|
|
|
|
|
|
R2 |
Residential |
73 |
70 |
N |
72 |
|
R3 |
Residential |
71 |
70 |
N |
69 |
|
Planned |
|
|
|
|
|
|
R6 |
Residential |
74 |
70 |
N |
69 |
|
R7 |
Residential |
74 |
70 |
N |
65 |
|
R8 |
Residential |
69 |
70 |
Y |
50 |
|
R9 |
Residential |
69 |
70 |
Y |
60 |
|
R10 |
Residential |
68 |
70 |
Y |
61 |
|
R12 |
Residential |
75 |
70 |
N |
63 |
|
R13 |
Residential |
75 |
70 |
N |
-[1] |
|
R14 |
Residential |
75 |
70 |
N |
56 |
|
R15 |
Residential |
74 |
70 |
N |
-[1] |
|
R16 |
Residential |
74 |
70 |
N |
52 |
|
R17 |
Residential |
72 |
70 |
N |
-[1] |
|
R18 |
Residential |
72 |
70 |
N |
26 |
|
R22 |
Residential |
70 |
70 |
N |
46 |
|
R23 |
Residential |
75 |
70 |
N |
33 |
|
R24 |
Residential |
76 |
70 |
N |
43 |
|
R25 |
Residential |
78 |
70 |
N |
-[1] |
|
R26 |
Residential |
75 |
70 |
N |
-[1] |
|
R27 |
Residential |
74 |
70 |
N |
-[1] |
|
R28 |
Residential |
73 |
70 |
N |
-[1] |
|
R29 |
Residential |
70 |
70 |
Y |
-[1] |
|
R30 |
Residential |
69 |
70 |
Y |
-[1] |
|
R31 |
Residential |
68 |
70 |
Y |
-[1] |
|
R32 |
Residential |
62 |
70 |
Y |
-[1] |
|
R33 |
Educational |
68 |
65 |
N |
58 |
Notes:
[1] NSRs are not affected by road traffic noise
in the without project scenario.
6.7.2.2
As shown in Table
6.12, exceedences
in road noise criterion on most NSRs are predicted in the range of 1 – 8dB(A).
Mitigation measures are, thus, required.
6.7.3
Mitigated Scenario
6.7.3.1
Direct mitigation measures including noise screening and
low noise road surface have been considered in terms of noise reduction
effectiveness, engineering and traffic safety.
6.7.3.2
Cantilevered noise barriers beside both the eastbound and
westbound carriageway of Road D9 were envisaged during the planning of Lohas
Park and were assumed by the developer to be provided upon opening of CBL.
These have been replaced with semi enclosure, which provides more effective
screening of traffic on Road D9. As known during the planning of Lohas
Park, noise barriers could not be provided at the junction of Road D9 and Road
R5. While further consideration has been given to extending the semi
noise enclosure, traffic sight line and visibility requirements would be
compromised at ground level by an extension of the enclosure panels and from
columns that would be needed to support decking over the junction area
itself.
6.7.3.3
Low noise road surface can further reduce road traffic at
source and this has been proposed for Road D9 from Wan Po Road and extending
onto the CBL bridge. The use of low noise road surface at the junction of
Road D9 and Road R5 is considered to be the best practicable mitigation in view
of the constraints preventing noise enclosure being provided in this location.
6.7.3.4
The locations and extent of the proposed mitigation
measures are shown in Drawing
no. 209506/EIA/NS/002. Section drawing for the proposed semi-enclosure is shown
in Appendix 6.16. A summary of these mitigation
measures to be provided for the operation of CBL is shown in Table 6.12a below.
Table 6.12a:
Summary of noise mitigation measures
|
No. |
Mitigation Measures |
NSRs to be Protected |
Noise Reduction, dB(A) |
|
N1 |
Approx. 300m
long low noise surfacing |
R2, R3, R6- R10, R12 – R18, R22 – R33 |
1 – 17 |
|
N2 |
Approx. 960m
long low noise surfacing |
||
|
N3 |
Approx. 220m
long 6m height + 17m width semi-enclosure |
||
|
N4 |
Approx. 245m
long 6m height + 10.5m width semi-enclosure |
||
|
N5 |
Approx. 22m long
6m height + 13.2m width semi-enclosure |
||
|
N6 |
Approx. 33m long
6m height + 17.4m width semi-enclosure |
||
|
N7 |
Approx. 90m long
6m height + 13.5m width semi-enclosure |
||
|
N8 |
Approx. 55m long
low noise surfacing |
6.7.3.5
Mitigated noise levels at the representative NSRs are
summarized in Table 6.13. Appendix 6.17 shows the detailed noise levels at various levels of the
NSRs.
Table 6.13: Predicted road traffic noise impact on
representative NSRs (Year 2036)
|
NSR No. |
Landuse |
CBL, dB(A) |
Other Roads, dB(A) |
Overall Noise Level, dB(A) |
Criterion, dB(A) |
Compliance (Y/N) |
|
Existing |
|
|
|
|
|
|
|
R2 |
Residential |
64 |
69 |
70 |
70 |
Y |
|
R3 |
Residential |
60 |
67 |
68 |
70 |
Y |
|
Planned |
|
|
|
|
|
|
|
R6 |
Residential |
64 |
66 |
68 |
70 |
Y |
|
R7 |
Residential |
65 |
63 |
67 |
70 |
Y |
|
R8 |
Residential |
61 |
35 |
61 |
70 |
Y |
|
R9 |
Residential |
60 |
59 |
62 |
70 |
Y |
|
R10 |
Residential |
58 |
60 |
62 |
70 |
Y |
|
R12 |
Residential |
66 |
62 |
67 |
70 |
Y |
|
R13 |
Residential |
66 |
44 |
66 |
70 |
Y |
|
R14 |
Residential |
66 |
56 |
67 |
70 |
Y |
|
R15 |
Residential |
66 |
50 |
66 |
70 |
Y |
|
R16 |
Residential |
66 |
54 |
66 |
70 |
Y |
|
R17 |
Residential |
65 |
57 |
65 |
70 |
Y |
|
R18 |
Residential |
64 |
56 |
65 |
70 |
Y |
|
R22 |
Residential |
62 |
63 |
66 |
70 |
Y |
|
R23 |
Residential |
66 |
57 |
67 |
70 |
Y |
|
R24 |
Residential |
68 |
55 |
68 |
70 |
Y |
|
R25 |
Residential |
70 |
48 |
70 |
70 |
Y |
|
R26 |
Residential |
68 |
-[1] |
68 |
70 |
Y |
|
R27 |
Residential |
68 |
-[1] |
68 |
70 |
Y |
|
R28 |
Residential |
67 |
-[1] |
67 |
70 |
Y |
|
R29 |
Residential |
66 |
-[1] |
66 |
70 |
Y |
|
R30 |
Residential |
65 |
-[1] |
65 |
70 |
Y |
|
R31 |
Residential |
64 |
-[1] |
64 |
70 |
Y |
|
R32 |
Residential |
59 |
-[1] |
59 |
70 |
Y |
|
R33 |
Educational |
45 |
50 |
51 |
65 |
Y |
Notes:
[1] NSRs are not affected by other roads.
6.7.3.6
With the implementation of the proposed mitigation measures as shown in Appendix
6.16, CBL will not
contribute to an exceedance of the noise criteria. All the residential premises
and educational institutions will be within the respective noise criterion of
70 dB(A) and 65 dB(A) respectively.
6.7.3.7
To study the noise performance of the project, traffic
noise levels at the residential properties and schools which have a direct line
of sight to the Project have been predicted. The numbers of dwellings and
classrooms that would benefit from and be protected by the provision of noise
mitigation measures have been calculated. The definition of “exposed”, “benefited” and
“protected” noise sensitive uses are defined as follow:
·
Exposed – Noise sensitive elements with unmitigated noise level greater
than relevant noise criteria
·
Benefited – Exposed noise sensitive elements with a noise reduction of
1.0 dB(A) or greater in overall noise level with the noise mitigation measures
in place
·
Protected – Exposed noise sensitive elements with an overall noise level
not greater than relevant noise criteria with the noise mitigation measures in
place
6.7.3.8
The number of dwellings that would benefit from and be
protected by the provision of noise mitigation measures will be identified for existing
residential premises and planned noise sensitive uses. The results for existing
and planned noise sensitive uses are presented in Table 6.14 below.
Table 6.14: Summary of protected and benefitted land
uses
|
NSE[1] |
Total No. of NSE |
Unmitigated Scenario |
Mitigated Scenario |
||
|
No. of Exposed NSE |
No. of Exposed NSE |
Protected NSE |
Benefitted NSE |
||
|
Existing |
|
|
|
|
|
|
Dwellings |
206 |
70 |
0 |
70 |
206 |
|
Planned |
|
|
|
|
|
|
Dwellings[2] |
4856 |
2280 |
0 |
2280 |
4848 |
|
Classroom[3] |
36 |
36 |
0 |
36 |
36 |
Notes:
[1] NSE –
Noise sensitive element
[2] As the
layout details showing rooms is not presently available, four dwellings will be
assumed for each floor.
[3] As the
layout details showing classrooms is not presently available, six classrooms
will be assumed for each floor.
6.7.4
Consideration of Indirect Technical Remedies
6.7.4.1
According to Section 6.2, Annex 3 of the TM-EIAO, it states
that upon exhaust of direct mitigation measures, indirect mitigation measure in
form of window insulation and air-conditioning is often the “last resort” in an
attempt to ameliorate the residual impact. As all the direct mitigation
measures have been exhausted, the eligibility of the affected premises for
indirect technical remedies is determined with reference to the following three
criteria:
·
the predicted overall noise level must be above a specified noise level
(e.g. 70 dB(A) for domestic premises and 65 dB(A) for education institutions,
all in L10,1hr);
·
the predicted overall noise level is at least 1.0 dB(A) more than the
prevailing traffic noise level, i.e. the total traffic noise level existing before
the works to construct the road were commenced; and
·
the contribution to the increase in the predicted overall noise level
from the road project must be at least 1.0dB(A).
6.7.4.2
The premises are eligible for ITR only if all the three
criteria are met. Since none of the receivers (shown in Tables 6.12) has met all three criteria, ITR is not required.
6.8
Assessment of Side Effects and Constraints
6.8.1.1
The adopted mitigation measures have been designed to
balance between feasibility and effectiveness. The scheme has avoided blockage
to the entrance way of the existing and planned premises. The induced impacts
from noise barrier will be separately discussed in Air Quality and LVIA
chapters.
6.9
Evaluation of Constraints on Planned Noise Sensitive Developments/Land
Uses
6.9.1.1
Adverse constraints on the planned noise sensitive
development/land uses are not anticipated. Therefore, no additional measures
within the planned noise sensitive uses are required.
6.10
Residual Environmental Impacts
6.10.1.1
It is expected that there will be no noise exceedance
during construction and operational phases of the CBL and Road D9 with proposed
mitigation measures implemented.
6.11.1.1
Construction noise assessment has been conducted. With the
implementation of mitigation measures and rescheduling the construction work
outside examination period, construction noise exceedance is not anticipated at
NSRs.
6.11.1.2
For the operational phase, practicable mitigation measures
have been proposed for Road D9 and CBL to ensure that traffic noise from these
roads will be well within the noise criterion. Semi-enclosures on Road D9 and
low noise road surface on Road D9 and CBL to protect the nearest noise
sensitive receivers of Lohas Park Area 86 development, which was previously
planned on the assumption of similar mitigation measures being provided in the
CBL project.
6.11.1.3
The mitigated noise levels at all noise sensitive receivers
would meet the relevant noise criteria and no indirect technical remedies are
required.
6.11.1.4
The noise assessment has been conducted accordingly to the
criteria and guidelines for evaluating and assessing noise impacts as stated in
Annexes 5 and 13 of the TM.
[j1]Needs update to 2017