4.2 Environmental Legislation, Policies,
Standards and Criteria
4.5 Potential Sources of Impacts
4.11 Monitoring and Audit Requirement
4.1.1
This Section
provides an evaluation of the potential noise impacts arising from the
construction and operation of the proposed Project. Appropriate mitigation
measures will be recommended, where necessary, in order to mitigate any
unacceptable impacts.
Construction Phase
4.2.1
The principal legislation relating to the control of
construction noise is the Environmental
Impact Assessment Ordinance (Cap. 499). The Technical
Memorandum on Environmental Impact Assessment Process (EIAO-TM), issued
under the EIAO, provides guidelines and noise criteria for evaluating noise
impacts. The assessment criteria
are defined in Annex 5 of the EIAO-TM.
4.2.2
The Noise Control
Ordinance (NCO) (Cap. 400) also provides means to assess construction noise
impacts. A number
of Technical Memoranda (TMs) have been issued under the NCO to stipulate control approaches and
criteria. The Technical Memorandum on Noise from Construction Work Other than
Percussive Piling (GW-TM) provides the guidelines for controlling the
construction noise from powered mechanical equipment (PME) in general
construction works during the restricted hours. The Technical Memorandum on Noise from Construction Works in Designated
Areas (DA-TM) provides the guidelines for controlling the use of Specified Powered Mechanical Equipment (SPME) and the
undertaking of Prescribed Construction Work (PCW)
during the restricted hours in designated areas.
General
Construction Works during Normal Working Hours
4.2.3
Under the EIAO,
potential noise impact arising from general construction works during normal
working hours (i.e. 0700 to 1900 hrs on any day not being a Sunday or general
holiday) at 1 m from the external façade of the noise sensitive uses, which
rely on opened windows for ventilation, is to be assessed in accordance with
the noise criteria specified in the EIAO-TM. The EIAO-TM
noise standards are presented in Table 4.1.
Table 4.1 ¡V EIAO-TM Day-time Construction
Noise Standards
|
Noise
Sensitive Uses |
Noise
Standard 0700 to 1900 hours on any day not being
a Sunday or general holiday Leq, 30 min (dB(A)) |
|
¡P
All domestics premises including
temporary housing accommodation |
75 |
|
¡P
Hotels and hostels |
75 |
|
¡P
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 which rely on opened windows for ventilation. (2) The
above standards shall be viewed as the maximum permissible noise levels
assessed at 1m from the external façade. |
|
General
Construction Works during Restricted Hours
4.2.4
The NCO provides
statutory controls on general construction works during restricted hours (i.e.
1900 to 0700 hours or any time on Sundays or general holidays). The use of PME for carrying out
construction works during these restricted hours would require a Construction
Noise Permit (CNP). The Noise Control Authority will assess all
CNP applications on a case-by-case basis and, in doing so the authority advises
that they will be guided by the GW-TM.
4.2.5 When assessing an application for CNP for the use of PME during restricted hours, the Noise Control Authority will compare the Acceptable Noise Levels (ANLs) specified in the GW-TM with the Corrected Noise Levels (CNLs) (i.e. after accounting for factors such as barrier effects and reflections) associated with the proposed PME operations. The NCO requires that noise levels from construction at affected Noise Sensitive Receiver (NSR) be less than the specified ANL. The ANLs are related to the inherent noise sensitivity of the noise receiver areas in question, and different Area Sensitivity Ratings (ASRs, i.e. A, B or C, see Table 4.2) have been established to reflect the background characteristics of different areas. Each noise receiver area is assigned an ASR based on its predominant land use and the presence, if any, of Influencing Factors (IFs) such as nearby industrial areas, major roads or airports. The appropriate ASR for the NSR is determined with reference to Table 4.2.
Table 4.2 ¡V Area Sensitivity Ratings
|
Degree to which NSR is affected by
Influencing Factor (IF) |
|||
|
Not Affected |
Indirectly Affected |
Directly Affected |
|
|
Rural area, including Country
Parks or village type developments |
A |
B |
B |
|
Low density residential area
consisting of low-rise or isolated high-rise developments |
A |
B |
C |
|
Urban area |
B |
C |
C |
|
Area other than those above |
B |
B |
C |
|
Notes: The following definitions apply: (a)
"Country Park" means an area that is designated
as a country park pursuant to section 14 of the Country Parks Ordinance;
(b)
"directly affected" means that the NSR is at such
a location that noise generated by the IF is readily noticeable at the NSR
and is a dominant feature of the noise climate of the NSR; (c)
"indirectly affected" means that the NSR is at
such a location that noise generated by the IF, whilst noticeable at the NSR,
is not a dominant feature of the noise climate of the NSR; (d)
"not affected" means that the NSR is at such a
location that noise generated by the IF is not noticeable at the NSR; and (e)
"urban area" means an area of high density,
diverse development including a mixture of such elements as industrial
activities, major trade or commercial activities and residential premises. |
|||
4.2.6
The relevant ANLs for each ASR are shown in Table
4.3.
Table
4.3 ¡V Acceptable Noise Levels (ANLs)
for General Construction Works to be carried out during Restricted Hours
(GW-TM)
|
Time
period |
Area Sensitivity Rating Leq, 5 min
(dB(A)) |
||
|
|
A |
B |
C |
|
All days during the evening (i.e.
1900-2300 hrs) and general holidays (including Sundays) during the day and
evening (i.e. 0700-2300 hrs) |
60 |
65 |
70 |
|
All days during the night-time (i.e.
2300-0700 hrs) |
45 |
50 |
55 |
|
Note: (a) The above standard applies to uses which
rely on opened windows for ventilation. |
|||
4.2.7
The Noise Control Authority will consider a well-justified CNP
application for construction works within restricted hours as guided by the
relevant Technical Memorandum issued under the NCO. The Noise Control Authority will take into account adjoining land uses and any previous complaints
against construction activities at the site before making a decision. Factors influencing the outcome of a CNP
application, such as the assigning of ANLs, would be determined by the Noise
Control Authority at the time of the application review based on the prevailing
site conditions which may change from time to time.
4.2.8
The DA-TM issued
under the NCO indicates a list of
SPME and the types of PCW to be regulated within restricted hours in Designated
Areas (DAs). Under the DA-TM, the use of five types of SPME and
the carrying out of three types of PCW within a designated area during
restricted hours would require a valid CNP. The SPME includes hand-held breaker,
bulldozer, concrete lorry mixer, dump truck and hand-held vibratory poker. The PCW are:
¡P
Erecting or dismantling of formwork or
scaffolding;
¡P
Loading, unloading or handling of rubble,
wooden boards, steel bars, wood or scaffolding material; and
¡P
Hammering.
4.2.9
Part of the Project Site (i.e. the southern section from the
Long Ping Station) falls within the designated area under the NCO. Hand-held breaker and concrete
lorry mixer specified as SPME will be used during the construction and the use
of these SPME during the restricted hours within the designated area shall be
controlled by the TM-DA. The Noise
Control Authority will assess the CNP applications based on procedures and
requirements as described in the DA-TM. In general, it should not be presumed
that a CNP would be granted for the carrying out of PCW within a designated
area during the restricted hours.
The CNP may be granted for the execution of construction works within a
designated area during restricted hours involving the use of SPME if the
relevant ANL and criteria stipulated in the DA-TM
can be satisfied. In the EIA stage, no use of SPME is proposed for the construction
works within the designated area during the restricted hours.
4.2.10
Percussive piling is prohibited between 1900 and 0700 hours
on any weekday not being a general holiday and at any time on Sunday or general
holiday. A CNP is required for the
carrying out of percussive piling between 0700 and 1900 hours on any day not
being a general holiday. Technical
Memorandum on Noise from Percussive Piling (PP-TM) sets out the requirements
for working and determination of the permitted hours of operations for the CNP
applications. The permitted hours
of operations would be 3, 5 or 12 hours per day depending on the types of
percussive piling and the predicted noise impact at NSRs.
Operation
Phase
4.2.12
The noise criteria, in terms of ANLs, stipulated in the IND-TM apply for all days and general
holidays. The ANLs are dependent on
the ASR of the NSRs and the time of the day and are presented in Table
4.4.
Table 4.4 ¡V ANLs for Fixed Noise Source under NCO
|
Time Period |
Leq 30min (dB(A)) |
||
|
ASR ¡§A¡¨ |
ASR ¡§B¡¨ |
ASR ¡§C¡¨ |
|
|
Day-time (0700 - 1900 hrs) |
60 |
65 |
70 |
|
Evening (1900 - 2300 hrs) |
60 |
65 |
70 |
|
Night-time (2300 - 0700 hrs) |
50 |
55 |
60 |
4.2.14
For the purpose of EIA, fixed plant noise associated with the
operation of a project is controlled under the EIAO. The noise standards are set out in the Annex 5 of EIAO-TM as follows:
¡P
The total fixed source noise level at the
façade of the nearest NSR is at least 5 dB(A) lower than the appropriate ANL
(as shown in Table 4.4) as specified in the Technical Memorandum for the
Assessment of Noise from Places Other than Domestic Premises, Public Places or
Construction Sites (IND-TM); or
¡P
Where the prevailing noise level in the
area is 5 dB(A) or more below the appropriate ANL, the total fixed source noise
level must not exceed this noise level.
4.2.15
According to the OZP No. S/YL-NSW/8, the proposed Barrage is
located within a ¡§Other Specified Uses¡¨ zone. Three assessment points were included in
the operational noise impact assessment to represent the nearest NSRs (TSSP1,
TTWS1 and SPCH1) to the proposed Barrage within 250m distance from the boundary
of the Yuen Long Industrial Estate, zoned as Other Specified Uses (OU)
(Industrial Estate) in the OZP.
Representative NSRs that may potentially be affected by the operation of
the proposed Barrage station are shown in Figure 4.1-4.6.
4.2.16
As stipulated in Annex 5 of the EIAO-TM, the noise standard
for planning purposes for fixed noise source are (a) 5 dB(A) below the
appropriate ANL, or (b) the prevailing background noise levels (for quiet areas
with level 5 dB(A) below the ANL).
In this regard, noise measurement was undertaken in the vicinity of the
representative NSRs near the proposed pumping stations to study the background
noise level. The noise measurement results and the lowest background noise levels recorded at
each NSR are presented in Section 4.3.2 and Table
4.5 respectively. Should
the background noise level be lower than the ANL by more than 5 dB(A), the
background noise level would be adopted as the assessment criteria.
4.2.17
In any event, the noise criterion
employed in this Report is for an
indicative operational noise assessment only. It should be noted that fixed noise
sources are controlled under Section 13
of the NCO. At the time of investigation, the Noise
Control Authority shall determine noise impact from concerned fixed noise
sources on the basis of prevailing legislation and practices being in force, and taking account of contemporary conditions /
situations of adjoining land uses.
Nothing in this Report shall bind the Noise Control Authority in the
context of law enforcement against any fixed noise source being assessed.
4.3.1
The existing ambient noise levels are mainly generated by
traffic along Castle Peak Road, West Rail Line and other local roads such as
Wang Lok Street. Background noise
sources also include existing processing plants and factories located in the
nearby Yuen Long Industrial Estate (YLIE) and Tung Tau Industrial Area (TTIA).
4.3.2
Background noise measurements to investigate the prevailing
noise levels at the representative NSR near the proposed pumping stations have
been undertaken from 2 June 2020 to 3 June 2020. The baseline noise measurement locations are provided
in Appendix 4.7. For the 3 sampling points,
the measured minimum background noise levels at night time
are all above the ANL-5 for ASR B while only the measured minimum background
noise levels at day & evening for TTWS1 is above the relevant ANL-5 level.
The measured background noise levels are summarized in Table 4.5.
Table 4.5
¡V Measured Baseline Noise Levels
|
NSR |
Time Period |
ANLs for Fixed Noise Source |
Measured Lowest Background Noise Level Leq 30min (dB(A)) |
Fixed Plant Noise Criteria (dB(A)) |
|
Tung Tau
Wai San Tsuen |
Day-time
(0700-1900) |
65 (60) |
71 |
60 |
|
Evening
(1900-2300) |
65(60) |
69 |
60 |
|
|
Night-time
(2300-0700) |
55 (50) |
60 |
50 |
|
|
Shan Pui
Chung Hau Tsuen |
Day-time
(0700-1900) |
65 (60) |
63 |
60 |
|
Evening
(1900-2300) |
65(60) |
58 |
58 |
|
|
Night-time
(2300-0700) |
55 (50) |
55 |
50 |
|
|
Village
house near Hong Kong School of Motoring |
Day-time
(0700-1900) |
65 (60) |
56 |
56 |
|
Evening
(1900-2300) |
65(60) |
53 |
53 |
|
|
Night-time
(2300-0700) |
55 (50) |
55 |
50 |
(a) All extraneous noise during the noise measurement were edited out.
(b) The number in brackets indicates the noise limit (ANL -5 dB(A)).
(c) The respective noise criteria is the lower of
the prevailing background noise level and ANL-5.
4.4.1
Representative noise sensitive receivers (NSRs) were
identified according to the criteria set out in the Technical Memorandum on
Environmental Impact Assessment Process (TM-EIAO). The Study Area for the
noise impact assessment covered an area of 300 m from the boundary of the
Project Site. Only the first layer of NSRs has been
identified for assessment as it would provide acoustic shielding to those
receivers at further distance behind.
4.4.2
The 300 m study area is within the Draft Yuen Long Outline
Zoning Plan (OZP) No. S/YL/24, Approved Nam Sang Wai OZP No. S/YL-NSW/8, Draft
Tai Tong OZP No. S/YL-TT/17 and Draft Tong Yan San Tsuen OZP No. S/YL-TYST/13.
The relevant OZP, Outline Development Plans and Layout Plans published by Lands
Department and the land use and development applications approved by the Town
Planning Board have been reviewed. Site survey has also been conducted for
identifying NSRs. A total of 55 existing representative NSRs have been
identified based on the site survey and review of the land use plans. The
identified representative NSRs during construction and operation phase are
shown in Table 4.6 and their locations are indicated in Figure 4.1-4.6 and
presented in Appendix 4.8,
respectively. In order to assess the worst-case scenario, the lowest floor of
the NSRs which are closest to the potential noise sources have been selected as
the assessment point.
Table 4.6 ¡V Representative Noise Sensitive Receivers (NSRs)
|
NSR |
Description |
Minimum Distance away from the Project (m) |
Type of Use |
Construction Phase |
Operation Phase |
|
TSSP1 |
Temporary
Shelter at Shan Pui |
72 |
Residential |
Yes |
Yes |
|
SPCH1 |
Shan
Pui Chung Hau Tsuen |
11 |
Residential |
Yes |
Yes |
|
TTWS1 |
Tung
Tau Wai San Tsuen |
39 |
Residential |
Yes |
Yes |
|
SPCH2 |
Shan
Pui Chung Hau Tsuen |
15 |
Residential |
Yes |
No |
|
WCTT1 |
Wang
Chau Tung Tau Wai |
89 |
Residential |
Yes |
No |
|
TNRG1 |
Twin
Regency |
30 |
Residential |
Yes |
No |
|
WCLU1 |
Wang
Chau Lam Uk Tsuen |
65 |
Residential |
Yes |
No |
|
YYGD1 |
Yuk Yat Garden |
50 |
Residential |
Yes |
No |
|
WFCT1 |
Wang
Fu Court |
16 |
Residential |
Yes |
No |
|
YUST1 |
Yeung
Uk San Tseun |
58 |
Residential |
Yes |
No |
|
YLLP1 |
Yuen
Long Long Ping Estate Wai Chow School |
66 |
Educational |
Yes |
No |
|
LSTS1 |
A.D.
& F.D.P.O.H. Ltd. Leung Shing Tak School |
70 |
Educational |
Yes |
No |
|
TSPE1 |
The
Spectra |
21 |
Residential |
Yes |
No |
|
HPHO1 |
Hor Ping House, Long Ping
Estate |
92 |
Residential |
Yes |
No |
|
SOLC1 |
Sol City |
14 |
Residential |
Yes |
No |
|
VHTK1 |
Village
house at Tai Kui |
13 |
Residential |
Yes |
No |
|
PFBD1 |
Po
Fai Building |
6 |
Residential |
Yes |
No |
|
MYBD1 |
Man Yip Building |
6 |
Residential |
Yes |
No |
|
FYBD1 |
Fuk Yip Building |
6 |
Residential |
Yes |
No |
|
FOHE1 |
Fook
On House |
13 |
Residential |
Yes |
No |
|
YFHE1 |
Yuen
Fat House |
6 |
Residential |
Yes |
No |
|
KSBD1 |
Kin
Shing Building |
6 |
Residential |
Yes |
No |
|
HLBD1 |
Healey
Building |
8 |
Residential |
Yes |
No |
|
WCMS1 |
Wah
Cheung Mansion |
6 |
Residential |
Yes |
No |
|
WSMS1 |
Wah
Shing Mansion |
6 |
Residential |
Yes |
No |
|
YLBD1 |
Yuen
Long Building |
6 |
Residential |
Yes |
No |
|
YTHE1 |
Yuen
Tong House |
6 |
Residential |
Yes |
No |
|
FYBD2 |
Fung
Yue Building |
6 |
Residential |
Yes |
No |
|
SFBD1 |
Siu
Fung Building |
6 |
Residential |
Yes |
No |
|
HPHE1 |
Happy
House |
6 |
Residential |
Yes |
No |
|
KHHE1 |
Kam
Hei House |
6 |
Residential |
Yes |
No |
|
CKHE1 |
Chi
King House |
19 |
Residential |
Yes |
No |
|
YCHE1 |
Yuen
Cheung House |
19 |
Residential |
Yes |
No |
|
HWBD1 |
Ho
Wang Building |
10 |
Residential |
Yes |
No |
|
WKBD1 |
Wah
Kin Building |
11 |
Residential |
Yes |
No |
|
CCHS1 |
Caritas
Yuen Long Chan Chun Ha Secondary School |
10 |
Educational |
Yes |
No |
|
YFGD1 |
Yee
Fung Garden |
39 |
Residential |
Yes |
No |
|
YLVA1 |
Yuen
Long Villa |
20 |
Residential |
Yes |
No |
|
SFCT1 |
Sun
Fai Court |
10 |
Residential |
Yes |
No |
|
MTTN1 |
Ma
Tin Tsuen |
11 |
Residential |
Yes |
No |
|
MTTN2 |
Ma
Tin Tsuen |
11 |
Residential |
Yes |
No |
|
LTTN1 |
Lung
Tin Tsuen |
11 |
Residential |
Yes |
No |
|
LAGR1 |
La
Grove |
30 |
Residential |
Yes |
No |
|
MTPK1 |
Ma Tin
Pok Village House |
30 |
Residential |
Yes |
No |
|
MTPK2 |
Ma Tin
Pok Village House |
90 |
Residential |
Yes |
No |
|
PKSN1 |
Park
Signature |
172 |
Residential |
Yes |
No |
|
TLTN1 |
Tin
Liu Tsuen |
11 |
Residential |
Yes |
No |
|
TLTN2 |
Tin
Liu Tsuen |
18 |
Residential |
Yes |
No |
|
TLTN3 |
Tin
Liu Tsuen |
7 |
Residential |
Yes |
No |
|
SCTN1 |
Sham
Chung Tsuen |
16 |
Residential |
Yes |
No |
|
PYVA1 |
Park
Yoho Venezia |
121 |
Residential |
Yes |
No |
|
CCST1 |
Cheung
Chun San Tsuen |
258 |
Residential |
Yes |
No |
|
RIVA1 |
Riva |
51 |
Residential |
Yes |
No |
|
KPTN1 |
Ko
Po Tsuen |
13 |
Residential |
Yes |
No |
|
KHWA1 |
Kam
Hing Wai |
141 |
Residential |
Yes |
No |
4.5.1
The Project includes the construction of the Barrage scheme,
modification of flow diversion structures in the intersection of Yuen Long
Nullah (YLN) and Yuen Long Bypass Floodway (YLBF), modification of parapet wall
along YLN, SCR and KTR, and Revitalisation Works in YLN. The major construction
activities for the above works will include ground breaking,
excavation, piling works, concreting works, superstructure works and softscape
& hardscape works. The locations of different works are indicated in Figure 4.1-4.6. Potential
sources of noise impacts during the construction phase of the Project will mainly
arise from powered mechanical equipment
(PME) operating at the construction work sites. The details of project construction are
given in Section 2.3. For
the decommissioning of low flow pumping station, there will be no demolition
works and only suspension of pumping operations will be involved.
4.5.2
Subject to vetting and approval to the foundation
schemes by relevant authority, percussive piling would be required for some of
the proposed facilities. The use of percussive piling will avoid the period
from November to March to minimize indirect impact to overwintering waterbirds.
Use of percussive piling would be subject to detail design in the future. Alternative piling method will be
considered as far as practicable to avoid using percussive piling. Should the
percussive piling construction method to be used for the Project, a CNP, as
mentioned in Section 4.2.10, will be applied during construction phase
of the Project.
4.5.3
Based on the current programme, no construction works will be
required during the restricted hours under the NCO. The normal working hours of the
construction of the Project will be between 0700 and 1900 hours from Monday to
Saturday (except general holidays).
Should evening and night works between 1900 and 0700 hours or on public
holidays (including Sundays) be required, the Contractor will submit a CNP
application which will be assessed by the Noise Control Authority.
4.5.4
During the operation phase, only minor maintenance works such
as regular clearance of debris inside the YLN and repair of damages to the
channel bed and sides are expected.
Thus, it is anticipated that the potential noise impacts arising from
these maintenance works would be minimal.
4.5.5
Noise will be generated from fixed plant sources during
operation, i.e. the pump sets and ventilation systems inside proposed pumping
stations of the Barrage Scheme. All
equipment will be accommodated inside the plant rooms and hence fully enclosed. Operational noise from the pumping
station is assumed to be emitted through the louvres. The fixed plant items for the proposed
pumping stations are given below which have been agreed with the project
proponent and relevant DSD divisions:
On each pumping station:
¡P
3 nos. of large capacity submersible flood
pumps;
¡P
3 nos. of submersible low flow pumps; and
¡P
5 nos. of ventilation fans.
4.5.6
As good practice, DSD staff will be required to ensure pump
room doors are kept closed. Traffic generated during operation will be very
limited as only 1 to 2 round trips is expected for the transportation of
personnel and equipment to conduct routine checking, servicing and maintenance.
Adverse traffic noise impact is therefore not expected during operation.
4.6.1
The construction noise impact assessment was undertaken in
accordance with the EIAO-TM and the
procedures outlined in the GW-TM issued
under the NCO. The assessment methodology is summarised
as follows:
¡P
Identify the representative NSRs that may
be affected by the construction of the Project;
¡P
Determine the plant items for
corresponding construction activities, based on the agreed plant inventory;
¡P
Assign sound power levels (SWLs) to the
PME proposed based on the GW-TM and list of SWLs of other commonly used PME([1]);
¡P
Calculate the correction factors based on
the distance between the NSRs and the notional noise source positions of different
works areas;
¡P
Apply corrections in the calculations,
such as potential screening effects and acoustic reflection, if any; and
¡P
Predict the construction noise levels at
NSRs in the absence of any mitigation measures.
4.6.2
The construction noise assessment was undertaken based on the
proposed construction works programme and plant inventory, and appropriate utilisation rates of the
PME items. Same utilization rates
have been used for the same type of PME among all works areas. The plant
inventory (including the type of equipment, their quantity and utilization
rate) in Appendix 4.2 have been
reviewed by the Project Engineer and confirmed to be appropriate and
practicable for completing the works within the proposed construction
programme.
4.6.3
The proposed methods for the
construction of the Project are common in Hong Kong and the PMEs proposed are
available in the Hong Kong market.
4.6.4
For the purpose of the construction noise assessment, the
entire construction site was divided into the following works areas:
¡P
Construction of Barrage Scheme including
E&M Control Room, Pumping Station A, Pumping Station B and Tidal Barrier
& Deepened Area C;
¡P
Modification of Flow Diversion Structures
in the intersection of YLN and YLBF;
¡P
Modification of Parapet Wall along YLN,
SCR and KTR; and
¡P
Revitalisation Works in YLN
4.6.5
The construction programme in shown in Appendix
4.1. The separate works
areas are presented in Figure 4.1-4.6.
4.6.6
The total SWL associated with each construction activity for
the corresponding works areas was established. The potential noise impacts at
NSRs were subsequently evaluated by comparing the predicted noise levels with
the EIAO-TM day-time construction
noise limits (Leq, 30min
dB(A)).
4.6.7
The methodology for the fixed plant noise impact assessment
follows the procedures outlined in the IND-TM. The methodology is summarised as
follows:
¡P
Identify types of equipment and the number
of equipment (if available);
¡P
Assign sound power levels (SWLs) to the
proposed equipment with reference to EIA studies in similar nature, noise data
from supplier, Good Practices on Pumping System Noise Control (GP-PS) and Good
Practices on Ventilation System Noise Control (GP-VS);
¡P
Identify representative NSRs that may be
affected by the fixed plant;
¡P
Calculate the correction factors, using a
conservative approach, based on the horizontal distance between the NSRs and
the fixed plant sources;
¡P
Calculate the corrected noise levels after
taking into account other corrections such as
potential screening effects, if any, by adopting standard acoustics principles;
and
¡P
Present the results in terms of Leq, 30min dB(A), as specified in the IND-TM.
4.6.8
For
the operational mode of the Barrage Scheme, the flood pumps will only operate
when the water level at the YLN reaches to the pre-set alarm level (except
routine maintenances), while the low flow pumps will operate regularly in
normal weather condition to discharge the dry weather flow from YLN during high
tide. The flood pumps will not operate together with the low flow pumps. The
operation of the proposed Barrage Scheme have been
commented and agreed with the project proponent and relevant DSD divisions in
the submission of Design Memorandum. For the operational noise assessment, only
the flood pumps and the ventilation fans are assumed to be operating as the
worst-case scenario.
4.6.9
The
flood pumps would be fully enclosed within the plant room with service hatch
doors which will remain closed during operation of the PME. Its building
materials are 150mm reinforced concrete and 225mm brick walls, at least 30
dB(A) of noise attenuation is assumed in the assessment.
4.6.10
Distance attenuation was taken into account in
the noise calculations where the direct distance between the nearest louvre and
each of the representative NSRs in the vicinity was estimated. All the mechanical screens and pumps
will be totally enclosed inside building structure. The ventilation fans will be fitted with
acoustic louvre/silencer. Barrier
correction was also considered in which a noise reduction of 10 dB(A) was
applied to the fixed plant depending on the line of sight of the representative
NSRs. A positive 3 dB(A) correction
was included in the calculations to predict the noise levels at the NSRs due to
façade effect. In the Environmental Review Report for application of Variation
of Environmental Permit (VEP) for Yuen
Long Kau Hui No. 2 Sewage Pumping Station with Environmental Permit (VEP-455/2014), the tonality correction of
0¡V3 dB(A) for four existing pumping stations nearby has been derived based on
noise measurement. With reference to the report, a positive 3 dB(A) tonality
correction was included in the noise calculation for the pumping stations.
4.6.11
No corrections have been applied for intermittency or
impulsiveness as such noise characteristics are not expected. If the noise shows any of these
characteristics during the operation of the plant, the noise limit should be
reduced in accordance with the recommendation indicated in Section 3.3 of IND-TM.
4.6.12 There would be some limitations such as the accuracy of the prediction for future conditions (e.g. plant inventory for the proposed construction works and fixed plant for future operation).
4.6.13
During
the assessment, realistic worst-case assumptions have been made in order to provide
a conservative assessment of noise impacts. The construction noise impact was
assessed based on conservative estimates for the types of plant and methods of
working. For operation noise assessment, being the worst-case scenario, all
items of equipment (i.e. 3 flood pumps and 5 ventilation fans at each pumping
station) have been assumed to operate simultaneously during the operation
period. For determining the distance correction factors, the horizontal
distances between the noise source positions and the NSRs were used for
representing the worst level of the representative NSRs for both construction
and operation phases.
4.7.1
The predicted façade noise levels during daytime period due
to the construction activities are calculated in accordance with the
methodology described in GW-TM. The highest predicted results at each
NSR are summarised in Table 4.7 with details of the noise calculations given in Appendix 4.3.
Table 4.7 ¡V Predicted Construction Noise Levels (Without Mitigation Measures)
|
NSR |
Description |
Maximum Predicted Noise Level, dB(A) |
Noise Criteria, Leq,
30min, dB(A) |
|
TSSP1 |
Temporary
Shelter at Shan Pui |
80 |
75 |
|
SPCH1 |
Shan
Pui Chung Hau Tsuen |
93 |
75 |
|
TTWS1 |
Tung
Tau Wai San Tsuen |
86 |
75 |
|
SPCH2 |
Shan
Pui Chung Hau Tsuen |
92 |
75 |
|
WCTT1 |
Wang
Chau Tung Tau Wai |
79 |
75 |
|
TNRG1 |
Twin
Regency |
88 |
75 |
|
WCLU1 |
Wang
Chau Lam Uk Tsuen |
82 |
75 |
|
YYGD1 |
Yuk Yat Garden |
84 |
75 |
|
WFCT1 |
Wang
Fu Court |
91 |
75 |
|
YUST1 |
Yeung
Uk San Tseun |
83 |
75 |
|
YLLP1 |
Yuen
Long Long Ping Estate Wai Chow School |
81 |
70/65
(a) |
|
LSTS1 |
A.D.
& F.D.P.O.H. Ltd. Leung Shing Tak School |
81 |
70/65
(a) |
|
TSPE1 |
The
Spectra |
89 |
75 |
|
HPHO1 |
Hor Ping House, Long Ping
Estate |
79 |
75 |
|
SOLC1 |
Sol City |
95 |
75 |
|
VHTK1 |
Village
house at Tai Kui |
95 |
75 |
|
PFBD1 |
Po
Fai Building |
98 |
75 |
|
MYBD1 |
Man Yip Building |
96 |
75 |
|
FYBD1 |
Fuk Yip Building |
98 |
75 |
|
FOHE1 |
Fook
On House |
94 |
75 |
|
YFHE1 |
Yuen
Fat House |
98 |
75 |
|
KSBD1 |
Kin
Shing Building |
94 |
75 |
|
HLBD1 |
Healey
Building |
94 |
75 |
|
WCMS1 |
Wah
Cheung Mansion |
94 |
75 |
|
WSMS1 |
Wah
Shing Mansion |
96 |
75 |
|
YLBD1 |
Yuen
Long Building |
92 |
75 |
|
YTHE1 |
Yuen
Tong House |
93 |
75 |
|
FYBD2 |
Fung
Yue Building |
96 |
75 |
|
SFBD1 |
Siu
Fung Building |
97 |
75 |
|
HPHE1 |
Happy
House |
91 |
75 |
|
KHHE1 |
Kam
Hei House |
98 |
75 |
|
CKHE1 |
Chi
King House |
90 |
75 |
|
YCHE1 |
Yuen
Cheung House |
88 |
75 |
|
HWBD1 |
Ho
Wang Building |
95 |
75 |
|
WKBD1 |
Wah
Kin Building |
95 |
75 |
|
CCHS1 |
Caritas
Yuen Long Chan Chun Ha Secondary School |
92 |
70/65
(a) |
|
YFGD1 |
Yee
Fung Garden |
87 |
75 |
|
YLVA1 |
Yuen
Long Villa |
90 |
75 |
|
SFCT1 |
Sun
Fai Court |
95 |
75 |
|
MTTN1 |
Ma
Tin Tsuen |
92 |
75 |
|
MTTN2 |
Ma
Tin Tsuen |
96 |
75 |
|
LTTN1 |
Lung
Tin Tsuen |
93 |
75 |
|
LAGR1 |
La
Grove |
85 |
75 |
|
MTPK1 |
Ma Tin
Pok Village House |
86 |
75 |
|
MTPK2 |
Ma Tin
Pok Village House |
79 |
75 |
|
PKSN1 |
Park
Signature |
75 |
75 |
|
TLTN1 |
Tin
Liu Tsuen |
100 |
75 |
|
TLTN2 |
Tin
Liu Tsuen |
95 |
75 |
|
TLTN3 |
Tin
Liu Tsuen(b) |
103 |
75 |
|
SCTN1 |
Sham
Chung Tsuen(b) |
92 |
75 |
|
PYVA1 |
Park
Yoho Venezia(b) |
77 |
75 |
|
CCST1 |
Cheung
Chun San Tsuen(b) |
71 |
75 |
|
RIVA1 |
Riva(b) |
83 |
75 |
|
KPTN1 |
Ko
Po Tsuen(b) |
90 |
75 |
|
KHWA1 |
Kam
Hing Wai(b) |
76 |
75 |
Notes:
(a) 70/65 denotes noise criteria during normal school days / examination
period, respectively
(b) Only hand-held tools will be used for the modification of parapet wall
4.7.2
Results indicate that the construction noise levels at most
of the representative NSRs exceeded the EIAO-TM
noise criteria in day-time during the course of the
construction period. Therefore,
mitigation measures will be required.
4.7.3
The predicted fixed plant noise levels at the representative
NSRs due to the operation of the proposed pumping stations are summarised in Table
4.8. The predicted noise
levels at all the representative NSRs within 300m from the pumping stations of
the Barrage Scheme comply with the noise criteria under EIAO as shown in Section 4.2.15. Details of the calculation are given in Appendix 4.6.
Table 4.8
¡V Predicted Fixed Plant Noise Levels due to the Proposed Pumping Stations
|
NSR |
Description |
Predicted Fixed Plant Noise
Level, dB(A) |
ASR |
Criterion, dB(A)(a) |
Exceedance |
|
TSSP1 |
Temporary Shelter at Shan Pui
|
46 |
B |
50 |
No exceedance |
|
SPCH1 |
Shan Pui Chung Hau Tsuen |
41 |
B |
50 |
No exceedance |
|
TTWS1 |
Tung Tau Wai San Tsuen |
38 |
B |
50 |
No exceedance |
Notes:
(a) Night time (23:00-7:00) ANL -5 as present is Table 4.5 was adopted
as the assessment criterion.
4.7.4
The operation noise of the proposed Barrage Scheme alone
shall comply with the criteria under the EIAO. The specified SWLs presented in Appendix
4.6 should be included in the tender specification. The suppliers of equipment should
guarantee the compliance of EIAO-TM noise criteria, with the characteristics of
tonality, impulsiveness and intermittency accounted for, by providing
certificate of measurement and verify the SWL during testing and commissioning
in accordance with international standard procedures. If necessary, the suppliers should apply
attenuation measures (e.g. use of silencers) to achieve the guaranteed noise
levels during the detailed design stage.
4.8.1
In view of the predicted noise exceedances during the
construction of the Project, the following mitigation measures have been
considered:
¡P
Good construction site practice;
¡P
Use of quiet PME;
¡P
Use of noise insulation sheet;
¡P
Adoption of movable noise barriers;
¡P
Adoption of fixed temporary noise barriers
¡P
Scheduling of PME / construction
activities; and
¡P
Quieter method.
Good Construction Site Practice
4.8.2
Good construction site practice and noise management can
considerably reduce the potential noise impact of the construction activities
on nearby NSRs. The noise benefits of these practices can vary according
to specific site conditions and operations. Since the effect of the good
construction site practices could not be quantified, the mitigated noise levels
calculated in the subsequent sections have not taken account of this
effect. The following site practices should be followed during the
construction of the Project:
¡P
Only well-maintained plant should be
operated on-site and plant should be serviced
regularly during the construction phase;
¡P
Silencers or mufflers on construction
equipment should be utilised and should be properly maintained during the
construction phase;
¡P
Mobile plant, if any, should be sited as
far away from NSRs as possible;
¡P
Machines and plant (such as trucks) that
may be in intermittent use should be shut down between work periods or should
be throttled down to a minimum;
¡P
Plant known to emit noise strongly in one
direction should, wherever possible, be orientated so that the noise is
directed away from the nearby NSRs; and
¡P
Material stockpiles and other structures
should be effectively utilised, wherever practicable, in screening noise from
on-site construction activities.
Use of Quiet PME
4.8.3 The use of quiet PME is considered to be a practicable means to mitigate the construction noise impact. Quiet PME is defined as a PME having actual SWL lower than the value specified in the GW-TM. The total SWL of all plant items to be used on-site at each works area will be specified so that flexibility is allowed for the Contractor to select plant items to suit the construction needs. The Contractor shall select plant items with total SWL equal to or lower than the total SWL specified in the plant inventory in Appendix 4.4 in order to meet the relevant noise criteria. Quiet PME that have been adopted in the assessment are summarised in Table 4.9.
Table 4.9 ¡V Sound Power Level of Quiet PME
|
PME |
EPD QPME Reference(a)(b) |
Sound Power Level (dB(A)) |
|
Generator |
EPD-07189 |
92 |
|
Dump truck, 5.5 tonne < gross vehicle weight ≤ 38 tonne |
EPD/PME/38 |
105 |
|
Excavator, wheeled/tracked |
EPD-07612 |
98 |
|
Crane, mobile |
EPD-09096 |
103 |
|
Note: (a)
¡§Sound power levels of other commonly used
PME¡¨ prepared by the Noise Control Authority (https://www.epd.gov.hk/epd/sites/default/files/epd/english/application_for_licences/guidance/files/OtherSWLe.pdf) (b)
Quality powered
mechanical equipment (https://www.epd.gov.hk/cgi-bin/npg/qpme/search_gen.pl?lang=eng&st=sim&valid=Y) |
||
Adoption of Movable Noise Barriers
4.8.4
The use of noise barriers will be an effective means to
mitigate the noise impact arising from the construction works, particularly for
low-rise NSRs. With reference to EIAO
Guidance Note No. 9/2010 Preparation of Construction Noise Assessment Under the
Environmental Impact Assessment Ordinance (EIAO GN No. 9/2010), the use of
movable barrier for certain PME could generally provide a 5 dB(A) reduction for
movable PME and 10 dB(A) for stationary PME. The schematic configuration of movable
noise barrier is presented in Appendix
4.9.
4.8.5
Noise insulating sheet would be adopted for PME such as drill
rig (Appendix 4.10). The
noise insulating sheet should be deployed such that there would be no opening
or gaps on the joints. With reference to the approved EIA
Report for West Island Line (WIL)
(Register No.: AEIAR-126/2008 approved on 23 Dec 2008) and MTRC
Contract C4420 Tsim Sha Tsui Modification Noise Assessment
Report for VEP (July 2003), a reduction of over 10 dB(A) could be
achieved with the use of the noise insulating sheet. For a
conservative assessment, a noise reduction of 10 dB(A) for the PME with
deployment of noise insulating sheet was assumed in this assessment.
4.8.6
In view of the close proximity
between NSRs and the works areas for revitalisation works inside nullah, fixed
temporary noise barriers will be deployed at the working section as far as
practicable. Fixed temporary noise barriers of 3m in
height with skid footing should be used and located within a few metres of
stationary plant and mobile plant such that the line of sight to the NSR is
blocked by the barriers. The length of the barrier should be at least
five times greater than its height. The noise barrier material should have a sufficient surface density of at least 7 kg/m2 and
have no openings or gaps. Reference has been made to EIAO GN No. 9/2010; it is anticipated that the major noise source
of movable PMEs, such as breaker, water pump, concrete lorry mixer and
excavator, will be located within the nullah at a level lower than the top of
the proposed fixed temporary noise barrier, and therefore these barriers could
produce at least a 5 dB(A) noise reduction.
4.8.7
The construction activities, especially the revitalisation
works in YLN, will be conducted section by section. The estimated duration of
for a single work section is about 2 months. No two works areas with less than
300m separation distance will be conducted at the same time.
4.8.8
It is considered practical to specify the quiet PME and noise
mitigation measures described in Section 4.8.3 in the contract
document to mitigate the construction noise impact.
4.8.9
With the implementation of the use of quiet PME and movable
noise barriers for various construction activities, the mitigated noise levels
at the representative NSRs were calculated and the results are summarised in Table
4.11 with details of the calculations
given in Appendix 4.5. The results indicated that the predicted
façade noise levels are in the range of 38 to 75dB(A) and 59 to 69dB(A) at
residential NSRs and educational NSRs, respectively.
4.8.10
The maximum predicted construction noise level at CCHS is 69
dB(A). This comply with the noise criteria of 70dB(A) during normal school days
but exceed the criteria of 65 dB(A) during examination period. However, this
potential exceedance can be avoided with following arrangement:
¡P
The contractor should liaise with the
school management about the arrangements during examination weeks; and
¡P
PMEs shall not be used at the closest
works areas (i.e. near CCHS1) during the examination period.
Quieter Methods / Considerations on Alternative
Construction Methods
4.8.11
Handheld or excavator mounted concrete breaker is a
traditional mechanical equipment for concrete breaking and removal. Using such
equipment will generate loud noise, with sound power levels generally range
from 108 dB(A) to 122 dB(A). The adoption of quieter equipment or methods for
concrete breaking or removal could be less noisy or could reduce the noise
propagation when necessary. These include high pressure water jet system,
handheld concrete crusher, medium duty breaker, blade saw, wire saw and noise
enclosure. Sound pressure of different quieter equipment or methods is listed
in Table
4.10. These measures shall be
adopted if the use of quiet PME is not sufficient in
reducing the construction noise level.
Table 4.10 ¡V Sound Pressure Level of
Quieter Equipment/Methods
|
Quieter Equipment / Methods |
Sound Pressure Level
in dB(A) at 7m from Equipment |
|
Non-Explosive Chemical Expansion Agent |
60 ¡V 65 |
|
Hand-Held Concrete Crusher |
67 ¡V 69 |
|
Quieter type Wire Saw or Diamond Wire Saw |
76 ¡V 81 |
|
Quieter type Blade Saw |
76 ¡V 81 |
|
Hydraulic Crusher for Concrete Breaking |
67 ¡V 69 |
|
High Pressure Water Jetting |
79 |
4.8.12
In addition to the potential adoption of offsite precast structures
/ modular integrated construction (MiC) for the
pumping stations & tidal barriers, as stated in Chapter 2, alternative construction methods have been considered to
reduce noise emission under the revitalisation works along the YLN. With
consideration of the risks of working in the nullah and the potential risk of
evacuation during construction, typical concrete breaking works using hand-held
percussive breakers have been assumed for assessment. The Contractor would be
required to propose equivalent and/or quieter methods of construction to
further minimise noise impacts and the methods mentioned in Table
4.10 will be adopted as far as possible.
4.8.13
With the above arrangements in place, no exceedance of the
noise criterion during examination period is anticipated and no unacceptable
impact is expected at the NSR at that particular period.
4.8.14
Table 4.11 shows that the highest predicted construction noise
levels at all NSRs comply with the noise criteria during the daytime period,
therefore, no unacceptable noise impact is expected to arise from the
construction activities to be carried out within the works areas.
Table 4.11 ¡V Predicted Construction Noise Levels (With Mitigation Measures)
|
NSR |
Description |
Predicted Noise Level, dB(A) |
Noise Criteria, Leq,
30min, dB(A) |
|
TSSP1 |
Temporary
Shelter at Shan Pui |
68 |
75 |
|
SPCH1 |
Shan
Pui Chung Hau Tsuen |
71 |
75 |
|
TTWS1 |
Tung
Tau Wai San Tsuen |
64 |
75 |
|
SPCH2 |
Shan
Pui Chung Hau Tsuen |
70 |
75 |
|
WCTT1 |
Wang Chau
Tung Tau Wai |
57 |
75 |
|
TNRG1 |
Twin
Regency |
65 |
75 |
|
WCLU1 |
Wang
Chau Lam Uk Tsuen |
60 |
75 |
|
YYGD1 |
Yuk Yat Garden |
62 |
75 |
|
WFCT1 |
Wang
Fu Court |
68 |
75 |
|
YUST1 |
Yeung
Uk San Tseun |
61 |
75 |
|
YLLP1 |
Yuen
Long Long Ping Estate Wai Chow School |
59 |
70/65
(a) |
|
LSTS1 |
A.D.
& F.D.P.O.H. Ltd. Leung Shing Tak School |
59 |
70/65
(a) |
|
TSPE1 |
The
Spectra |
67 |
75 |
|
HPHO1 |
Hor Ping House, Long Ping
Estate |
57 |
75 |
|
SOLC1 |
Sol City |
72 |
75 |
|
VHTK1 |
Village
house at Tai Kui |
72 |
75 |
|
PFBD1 |
Po
Fai Building |
75 |
75 |
|
MYBD1 |
Man Yip Building |
74 |
75 |
|
FYBD1 |
Fuk Yip Building |
75 |
75 |
|
FOHE1 |
Fook
On House |
71 |
75 |
|
YFHE1 |
Yuen
Fat House |
75 |
75 |
|
KSBD1 |
Kin
Shing Building |
72 |
75 |
|
HLBD1 |
Healey
Building |
72 |
75 |
|
WCMS1 |
Wah
Cheung Mansion |
72 |
75 |
|
WSMS1 |
Wah
Shing Mansion |
74 |
75 |
|
YLBD1 |
Yuen
Long Building |
70 |
75 |
|
YTHE1 |
Yuen
Tong House |
71 |
75 |
|
FYBD2 |
Fung
Yue Building |
74 |
75 |
|
SFBD1 |
Siu
Fung Building |
75 |
75 |
|
HPHE1 |
Happy
House |
68 |
75 |
|
KHHE1 |
Kam
Hei House |
75 |
75 |
|
CKHE1 |
Chi
King House |
68 |
75 |
|
YCHE1 |
Yuen
Cheung House |
66 |
75 |
|
HWBD1 |
Ho
Wang Building |
72 |
75 |
|
WKBD1 |
Wah
Kin Building |
73 |
75 |
|
CCHS1 |
Caritas
Yuen Long Chan Chun Ha Secondary School |
69 |
70/65
(a) |
|
YFGD1 |
Yee
Fung Garden |
64 |
75 |
|
YLVA1 |
Yuen
Long Villa |
67 |
75 |
|
SFCT1 |
Sun
Fai Court |
72 |
75 |
|
MTTN1 |
Ma
Tin Tsuen |
70 |
75 |
|
MTTN2 |
Ma
Tin Tsuen |
74 |
75 |
|
LTTN1 |
Lung
Tin Tsuen |
71 |
75 |
|
LAGR1 |
La
Grove |
62 |
75 |
|
MTPK1 |
Ma Tin
Pok Village House |
63 |
75 |
|
MTPK2 |
Ma Tin
Pok Village House |
56 |
75 |
|
PKSN1 |
Park
Signature |
52 |
75 |
|
TLTN1 |
Tin
Liu Tsuen |
67 |
75 |
|
TLTN2 |
Tin
Liu Tsuen |
62 |
75 |
|
TLTN3 |
Tin
Liu Tsuen |
70 |
75 |
|
SCTN1 |
Sham
Chung Tsuen |
59 |
75 |
|
PYVA1 |
Park
Yoho Venezia |
44 |
75 |
|
CCST1 |
Cheung
Chun San Tsuen |
38 |
75 |
|
RIVA1 |
Riva |
50 |
75 |
|
KPTN1 |
Ko
Po Tsuen |
57 |
75 |
|
KHWA1 |
Kam
Hing Wai |
43 |
75 |
Notes:
(a) 70/65 denotes noise criteria during normal school days / examination
period, respectively
4.8.15
While no unacceptable noise impact is expected due to the
operation of fixed plant items, it is still recommended that the following
measures be implemented as far as practicable to minimise the potential impact:
¡P
Quieter plant should be chosen as far as
practical;
¡P
Include noise levels specification when
ordering new plant items;
¡P
All openings, including louvres for
ventilation and machine room doors should be oriented away from the NSRs as far
as practicable;
¡P
Silencers, acoustic louvres or acoustic
doors should be used where necessary; and
¡P
Develop and implement a regularly
scheduled plant maintenance programme so that plant items are properly operated
and serviced. The programme should
be implemented by properly trained personnel.
4.8.16 Testing and commissioning of the proposed pumping stations would be carried out prior to operation. Noise monitoring would be carried out by the Contractor to ensure fixed noise sources impact would comply with the relevant noise standards.
Construction
Phase
4.9.1
There
are three concurrent projects potentially causing cumulative noise impacts.
They are:
¡P
Improvement of Yuen Long Town Nullah (Town
Centre Section);
¡P
Elevated Pedestrian Corridor in Yuen Long
Town Connecting with Long Ping Station; and
¡P
Housing Sites in Yuen Long South.
Improvement
of Yuen Long Town Nullah (YLTN)
4.9.2
With
reference to the EIA Report of improvement works, the project is tentatively
scheduled to commence in second quarter of 2021 for completion in early
2026. Since the revitalisation
works in YLN will be commence at late 2027, there is no overlap of the project
programme of the YLTN project and YLBS Project. No cumulative noise impact is
anticipated.
Housing
Sites in Yuen Long South
4.9.3
According
to the EIA report of the housing development, no unacceptable noise impact is
anticipated by good site practices, use of noise barrier, ¡§quiet¡¨ plant and
working method. The TLTN1 ¡§Tin Liu Tsuen¡¨ would be the closest NSR to the
housing development and the maximum predicted mitigated noise level from the
YLBS Project is 52 dB(A). No unacceptable cumulative noise impact is
anticipated.
Elevated
Pedestrian Corridor in Yuen Long Town Connecting with Long Ping Station (EPC)
4.9.4 For EPC in Yuen Long Town Connecting with Long Ping Station, the construction period will overlap with that of the Project during 2022 to 2026. It is noted that the tentative commencement of the project is under reviewed. Since the revitalisation works in YLN will be commence at late 2027, based on the available information there is no overlap of the project programme of the EPC project and YLBS Project. No cumulative noise impact is anticipated.
Operation
Phase
4.9.5
Based
on current available information, no concurrent fixed plant has been identified
within 300m from the Barrage Scheme.
As such, cumulative operational noise impact is not anticipated.
Construction Phase
4.10.1
With the implementation of practical noise mitigation measures,
including the use of quiet PME, movable noise barriers, noise insulation sheet
and scheduling of construction activities, it is predicted that there is no
exceedance of the daytime construction noise criteria at all NSRs. Therefore, unacceptable residual impact
is not anticipated.
Operation Phase
4.10.2
Both the predicted noise levels due to the operation of the
proposed pumping stations comply with the day-time and
night-time noise criteria. Thus,
unacceptable residual impacts are not anticipated from the operation of the
Project provided that the appropriate contract specifications and noise
abatement measures as mentioned in Section 4.8 are incorporated in the
Detailed Design.
Construction
Phase
4.11.1
The recommended mitigation measures, monitoring procedures
and locations are presented in detail in the Environmental Monitoring and Audit (EM&A) Manual. This will
facilitate the contractor to have early warning and undertake the necessary
actions to reduce noise emissions at specific areas. The effectiveness of on-site control
measures could also be evaluated through the regular site audits. All the recommended mitigation measures
should be incorporated into the EM&A programme for implementation during
construction.
Operation
Phase
4.11.2 Noise monitoring for the operation of the Barrage Scheme is considered unnecessary during the operation phase.
Construction
Phase
4.12.1
A construction noise assessment has been undertaken to
predict the noise levels at the representative NSRs due to the construction of
the Project. Practicable mitigation
measures, including good construction site practices, use of quiet construction
plant, movable noise barriers, noise insulation sheet and scheduling of
construction activities, have been recommended. With the implementation of the
recommended mitigation measures, the predicted construction noise levels at all
NSRs comply with the noise criteria during
the daytime period. Therefore, no
unacceptable noise impact is expected to arise from the construction
activities. Also, no unacceptable
cumulative impact or residual impact is anticipated. Regular noise monitoring at NSRs as part
of the EM&A programme during the construction stage is recommended.
Operation
Phase
4.12.2
Potential noise impact from the operation of the proposed
pumping stations has been assessed.
The predicted fixed plant noise levels at the representative NSRs due to
the operation of the proposed Barrage Scheme comply with the day-time
and night-time noise criteria. No
unacceptable residual impact is anticipated. Attenuation measures, if required, will
be provided to the fixed plant items for achieving the compliance of EIAO-TM noise
criteria during the detailed design stage.