This section
provides an evaluation of the noise impacts arising from the construction and
operation of the LNG terminal proposed on Black Point. Activities during the construction phase,
including reclamation, site formation and building construction and fixed plant
noise sources during operational phase, have the potential to cause noise
impacts to the surrounding area.
Appropriate mitigation measures will be recommended, where necessary, in
order to mitigate any adverse impacts.
5.2
Legislation Requirement and Evaluation Criteria
5.2.1
Construction
Phase
General
The
noise impacts associated with the LNG terminal construction will be assessed
according to the Environmental Impact Assessment
Ordinance (Cap.499) and its Technical
Memorandum, EIAO-TM. The assessment
criteria are defined in Annex 5 of
the EIAO-TM and the principal
legislation for controlling construction noise is the Noise Control Ordinance, Cap. 400 (NCO). A number of technical memoranda (TMs) have
been issued under the NCO to stipulate control approaches and criteria and
those which may be relevant to the construction of the terminal include the
following:
·
Technical Memorandum on Noise from Construction Work
Other than Percussive Piling (GW-TM) which provides the guidelines for
controlling the construction noise from power mechanical equipment (PME) in
general construction works.
·
Technical Memorandum on Noise from Construction Work
in Designated Areas (DA-TM) which deals with control of noise generated by specified
powered mechanical equipment (SPME) and prescribed construction work (PCW)
within designated areas.
·
Technical Memorandum on Noise from Percussive Piling (PP-TM)
which addresses the control of noise from percussive piling in addition to
issuance of Construction Noise Permit (CNP).
Percussive
Piling
Under the PP-TM, percussive piling is prohibited
at any time on Sundays and public holidays and during evening and night-time
hours (1900 - 0700 hours), Monday through Saturday. A CNP is required in order to carry out such
work during daytime hours (0700 - 1900 hours) Monday through Saturday. In addition,
percussive piling is prohibited at any time on Sundays and public holidays and
during evening and night-time hours (1900 - 0700 hours), Monday through
Saturday.
As the issuance
of a CNP by the Noise Control Authority
would depend on the submission of an application by the contractor, and
therefore on the contractor’s compliance with the percussive piling noise
limits set out within the PP-TM, the
assessment of this type of noise has not been included in this EIA.
General
Construction Works During Restricted Hours
The
NCO provides statutory controls on
general construction works during restricted hours (i.e., 1900 - 0700 hours
Monday to Saturday and at any time on Sundays and public holidays). The use of PME for carrying out construction
works during these restricted hours would require a 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.
When assessing
an application for the use of PME, the Noise
Control Authority will compare the Acceptable
Noise Levels (ANLs) specified in the GW-TM with the CNLs
(adjusted for any barrier and reflection effects) associated with the proposed
PME operations. The NCO requires that noise levels from construction at affected NSR be
less than the specified ANL. The ANLs are related to the inherent noise sensitivity of the
noise receiver areas in question, which in turn relate to the background noise
characteristics of these areas. Each
noise receiver area is then assigned an Area Sensitivity Rating (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 relevant ANLs are shown in Table
5.1. 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. It should be noted that nothing in this report shall bind the Noise Control Authority in making their
decision. If a permit is to be issued,
the Authority shall include any condition it thinks fit,
and such conditions shall be followed while the works covered by the permit are
being carried out. Failure to comply
with any conditions could result in the cancellation of the permit and
prosecution action under the NCO.
Table 5.1 Acceptable Noise Levels (ANLs) for General Construction Works to be carried out
during Restricted Hours (a)
|
Time
Period |
Area Sensitivity
Rating LAeq, 5 min (dB(A)) |
||
|
A |
B |
C |
|
|
All days during the
evening (1900 - 2300 hours) and general holidays (including Sundays) during
the daytime and evening (0700 - 2300 hours) |
60 |
65 |
70 |
|
All days during the
night-time (2300 - 0700 hours) |
45 |
50 |
55 |
|
Note: (a)
The above standard
applies to uses which rely on opened windows for ventilation. |
|||
General
Construction Works During
Although
the NCO does not provide for the
control of noise from construction activities during normal working hours (0700
- 1900, Monday to Saturday), Annex 5
of the EIAO-TM specifies a limit of Leq, 30 min 75 dB(A) for residential NSRs. Annex 5
also provides construction noise limits of Leq, 30 min 70 dB(A) and 65 dB(A) for schools during normal
teaching periods and examination periods respectively.
5.2.2
Operational Phase
Fixed
plant noise is controlled under Section
13 of the NCO and the predictions
will be undertaken in accordance with the IND-TM. The criteria noise limits are set out in the EIAO-TM as follows:
·
The total fixed source
noise level at the facade of the nearest NSR is at least 5 dB(A) lower than the
appropriate ANL (as shown in Table 5.2)
as specified in the Technical Memorandum
on Noise from Places other than Domestic Premises, Public Places or
Construction Sites (IND-TM); or
·
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.
The
criteria noise limits stipulated in the IND-TM
apply for all days and general holidays and are dependent on the Area
Sensitivity Rating (ASR) of the NSRs, as shown in Table 5.2.
Table
5.2 ANLs to be
used as Operational Noise Criteria
|
Time Period |
LAeq 30min
(dB(A)) |
||
|
ASR “A” |
ASR “B” |
ASR “C” |
|
|
Daytime (0700 – 1900) |
60 (55) |
65 (60) |
70 (65) |
|
Evening (1900 – 2300) |
60 (55) |
65 (60) |
70 (65) |
|
Night-time (2300 – 0700) |
50 (45) |
55 (50) |
60 (55) |
|
Note: The number in brackets
indicates the noise limit (ANL -5) for operational noise impact assessment. |
|||
As the site is
located in a rural area and no influencing factors affect the NSRs which are located at more than 1.6 km away from the
site in addition to a hill (the Black Point Headland) from the site. An ASR “A” has been assumed for the NSR
located in the vicinity of the proposed site.
Baseline noise measurement has been conducted to investigate the
prevailing noise levels at Black Point and to establish the noise limit for the
assessment of the operational noise impact.
Detail of the noise measurement will be further discussed in Section
5.3.3.
The Area
Sensitive Rating assumed 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.
5.3
Baseline Environmental Conditions and Noise
Sensitive Receivers
5.3.1
Baseline
Environmental Conditions
The site is
surrounded by the Black Point Headland (southeast to the site) and the existing
Black Point Power Station is located to the northeast of the site. The north and west of the proposed site is open
sea. The background noise environment is
dominated by the fixed plant noise from the operation of the Black Point Power
Station and the operation of the concrete batching plant, fabrication yard and
barging point located behind the headland for the Shenzhen Western Corridor
Project ; and road traffic noise from Lung Kwu Tan
Road (Figure
5.3a). The concrete batching
plant, fabrication yard and barging point is scheduled to be decommissioned by
the end of 2006, prior to the initiation of construction of the Project.
5.3.2
Noise
Sensitive Receivers
The nearest NSR
is identified as the village house at Lung Kwu Sheung Tan (N1) which is located at approximately 1.6 km
away from the site. However, this
village house (N1) is used as an office for the outdoor karting
track, according to the approved EIA Report for Proposed Karting
Track in D.D.134, Lung Kwu Sheung
Tan, Tuen Mun
(AEIAR-096/2006) (Annex 5-A). To present a worse case scenario, the noise
impact at this village house has been assessed.
In addition, the Black Point Headland located between the proposed site
and the NSR N1 will act as a substantial barrier to reduce the potential
construction and operational noise impact to N1. Terrain profile between N1 and the LNG
terminal is given in Annex 5-B. The location of the NSR is shown in Figure 5.3a. No planned NSR is identified within 2 km from
the site.
5.3.3 Baseline
Noise Measurement
To
investigate the prevailing noise levels at the NSR, a continuous 24-hour noise
measurement was made from 24 to 25 January 2006 at the 1st floor level of village house (N1) (Figure 5.3b). The noise measurement was conducted using
SVAN 949 Sound Level Meter (Type 1) and was calibrated using B&K Sound
Level Calibrator Type 4231 with a calibration signal of 94.0 dB(A) at
1kHz. The measurement was conducted with reference to the calibration and
measurement procedures as stated in the IND-TM.
The
measurement results are summarised in Table 5.3 and a
timeline chart showing the prevailing noise levels is presented in Figure 5.3c.
Table
5.3 Measured Prevailing Facade Noise Level
|
Period |
|
LAeq,
30min
dB(A) |
|
|
|
Minimum |
Average |
Maximum |
|
0700 – 2300 hours |
50 |
63 |
68 |
|
2300 – 0700 hours |
39 |
46 |
51 |
As the most
conservative case, the minimum measured prevailing noise level of 39 dB(A)
during night-time period, which is lower than the (ANL-5) criterion, will be
adopted as the stipulated noise limit for the assessment of operational noise
impacts.
5.4
Potential Sources of Impacts
5.4.1
Construction
Phase
Potential
impacts to the NSR during the construction phase of the LNG terminal will
mainly arise from PME operating at construction work sites. The major construction work will include the
following key activities:
·
Land based works:
- Site clearance;
- Soil compaction; and
- Blasting and excavation.
·
Reclamation:
-
Dredging;
-
Seawall Construction;
-
Placing fill; and
-
Drainage Works.
· Main Jetty works:
-
Ground Investigation;
-
Construction of jetties and access bridge;
-
Dredging of approach channel and turning basin; and
-
Intake and Outfall construction.
· Civil works at terminal:
-
Civil and structural construction works for the terminal facilities.
The
construction noise assessment will be undertaken based on the construction
programme and plant inventories summarised in Annexes 5-C and 5-D
respectively.
The plant inventory has been
checked by Project Proponent and is confirmed to be practical and feasible to
complete the Project within the scheduled timeframe and the PMEs
are available in the market. Liaisons on the blasting works are being conducted with the Mines
Division of GEO and CEDD in the preparation of the report.
The standard
working hours will be from 0800 to 1800 hours, however, the following works may
be carried out during the evening period:
·
Blasting and excavation works;
·
Dredging by the larger Trailing Suction
Hopper Dredger (TSHD);
·
Clearing and crushing of the blasted
rocks and their transportation off site during the evening;
·
Occasional large concrete pours on the
jetty head or outfall, if daytime temperatures are high; and
·
Facility construction works for the
terminal facility including tank construction.
It should be
noted that the construction activities associated with site formation will not
be carried out during the restricted hours (1900 – 0700 hours). For a worse case assessment, we have examined
noise elevations assuming 24-hour working.
5.4.2
Operational
Phase
Noise
associated with the operational phase of the LNG Terminal would mainly arise
from the plant at the terminal site. The
dominant noise sources are mainly from the machinery including the following
equipment:
· Heat exchangers, including LNG submerged combustion vaporizers;
· Compressors and diesel emergency generators;
· Various kind of pumps; and
· Special equipment such as unloading arms and nitrogen generator.
The noise data
for the equipment have made reference to manufacturers’ data and the results of
field measurement conducted at overseas LNG terminal. To
minimise the noise impact to the environment, most of the noise sources will be
housed within individual enclosures or claddings. As a
conservative approach, it is assumed that all equipment will be operated on a
24-hour basis. With reference to the
overseas LNG terminals, the equipment inventory are developed by the Engineers
and their respective sound power levels (SWLs) in
one-one octave band provided by the Project Proponent are presented in Annex 5-E.
The suppliers
of equipment should guarantee the specified SWL and the equipment should be
free of the characteristics of tonality, impulsiveness and intermittency, by
providing certificate of measurement and verify the SWL during testing and
commissioning in accordance with international standard procedures. With such guarantee included in LNG
Procurement Contract, the noise emission from the equipment should comply with
the tender specification. If necessary,
the suppliers should apply attenuation measures to achieve the guaranteed noise
levels determined during the detailed design stage. The proposed equipment is also confirmed to
be available in the market.
5.5.1
Construction
Phase
Construction
Works Carried out During
The
methodology for the noise impact assessment is in accordance with the
procedures outlined in the GW-TM, which
is issued under the NCO and the EIAO-TM, and is summarized as follows:
·
Identifying the likely type, sequence
and duration of principal noisy construction activities required for the
implementation of the project;
·
Identifying a list of construction plant
likely to be required for each construction activity;
Calculating the maximum total SWL for each construction
activity using the plant list and SWL data given for each plant in the
technical memorandum. When the PME is
not listed in the TMs, SWLs
provided in the document prepared by the Noise
Control Authority
(http://www.epd.gov.hk/epd/english/application_for_licences/guidance/files/OtherSWLe.pdf
) and British Standard 5228, Noise and
Vibration Control on Construction and Open Sites - Part 1 (BS5228: Part 1:
1997) ([1])
are referred;
·
Identifying representative NSRs as defined by the EIAO-TM
based on existing and committed land uses in the Study Area that may be
affected by the worksite;
·
As a conservative approach, calculating
the distance attenuation to NSR from nearest worksite; and
·
Predicting construction noise levels at
NSRs in the absence of any mitigation measures.
Using a conservative
approach, each work activity has been assumed to operate simultaneously and the
time schedule of each activity has been provided in Annex 5-C. Based on the
construction programme, cumulative noise impact
throughout the construction phase has been assessed.
Due to the
large separation distance plus a hill located between the construction site and
the NSR (approximately 1.6 km), the noise will be reduced due to energy lost
through atmospheric absorption during transmission, therefore the correction
factor for the atmospheric absorption has been calculated based on ISO 9613([2])
procedure. Additionally, a facade
correction of +3 dB(A) is applied.
Predictions are made of the most conservative case construction noise
levels at the identified representative NSR.
Construction
Works Carried out during Restricted Hours
Considering
the construction programme of the Project, night-time construction works will
need to be carried out. The site is
located outside designated area as defined in DA-TM and the construction noise assessment for night-time works
has been carried out in accordance with the requirements of the GW-TM in the context of programming
only.
5.5.2
Operational
Phase
The
methodology for the noise impact assessment is in accordance with the
procedures outlined in the ISO 9613-1(1) and IND-TM, which is issued under the NCO and the EIAO-TM.
The methodology
for the fixed plant noise assessment is presented below:
·
Identifying types of equipment and the
number of equipment;
·
Calculating the maximum total SWL for
each type of equipment;
·
Identifying representative NSRs as defined by the EIAO-TM
based on existing and committed landuses in the Study
Area that may be affected by the worksite;
·
Calculating the distance attenuation to
the NSRs from noise sources; and
·
Presenting the results in terms of LAeq (30min) dB, as specified in the TM.
With the
considerable separation between the site and the noise sensitive receivers, the
atmospheric absorption during sound transmission is considered as one of the
major factors that will have a significant impact on the noise prediction. Assessment results have been predicted in a
conservative approach without other attenuations due to foliage of trees and
shrubs, ground effects and buildings/claddings in which the equipment are
placed.
The predicted
noise levels at the NSR are compared with the criteria set out in Section 5.3.3. Mitigation measures will be proposed should
any exceedance be predicted.
5.6.1
Construction
Phase
Construction
Works Carried out During
The
unmitigated construction noise levels at the NSR N1 (Village house at Lung Kwu Sheung Tan) have been
predicted and are presented in Annex 5-F. The predicted construction noise levels at N1
are in the range of 35 - 44 dB(A), which are below the daytime construction
noise criterion of 75 dB(A) throughout the construction period and utilized the
conservative set of assumptions in the analysis.
Percussive
Piling
Percussive
piling will be utilised for the construction of the trestle and LNG jetty. As
the issuance of a CNP for percussive piling by the Noise
Control Authority would depend on the submission of an application by the
contractor, and therefore on the contractor’s compliance with the percussive
piling noise limits set out within the PP-TM,
the assessment of this type of noise has not been included in this assessment. However, the contractors will follow the
procedure set out in the PP-TM, as
described in Section 5.2.1 to assess
the noise impact in the application of the CNP.
Construction
Works carried out during Restricted Hours
The predicted noise
levels as shown in the Annex 5-E are
within the ANLs stipulated in GW-TM throughout the restricted hours. As described in Section 5.2.1, a CNP is required for the construction
works being carried out during the evening and night-time period (1900 - 0700 hours) Monday through Saturday.
As
mentioned in Section 5.4.1, some of
the construction works may be carried out during restricted hours based on the
preliminary implementation programme. Without evening and night-time works, the
project will be delayed by 5 – 8 months.
Assessment on the construction works to be carried out during restricted
hours (1900 – 0700 hours) is included to preliminarily appraise the feasibility
in the context of programming. However,
it should be noted that the assessment provided here is for indicative purpose
only and serves as a reference for the future design and construction
stage. Whether a CNP could be issued
would be subject to the discretion of the Authority taking into account of the
details and information provided and the circumstance when the CNP application
is filed. The actual amount of
construction work and the resultant noise levels would be compiled with the
requirement of CNP.
Cumulative
Impact
The
construction of karting track (as mentioned in Section 5.3.2) has been completed and it
is operational in August 2006. In
addition, the village house (NSR N1) within the karting
track site is used as an office.
As mentioned in
Section 3.7, there will be no
concurrent major projects to be constructed in the vicinity of the NSR, and
therefore no cumulative impact from the construction of the LNG terminal and
other designated projects is anticipated.
5.6.2
Operational
Phase
The most
conservative case noise levels at the NSR N1 (Village house at Lung Kwu Sheung Tan) during the
operational phase of the LNG terminal have been predicted. The detailed calculation of the predicted
noise level is presented in Annex 5-G. The predicted noise level is 33 dB(A) and is
below the stipulated noise criterion during daytime and night-time period.
Cumulative
Impact
The approved EIA Report for Proposed Karting Track
in D.D.134, Lung Kwu Sheung
Tan, Tuen Mun
(AEIAR-096/2006) (Annex 5-A) has been
reviewed to evaluate the cumulative operational noise impact. According to the approved EIA report, a 7.5 m
high barrier will be provided for the NSR N1 (village house) if it is used for
noise sensitive purpose. The predicted
noise level at the village house is up to 50 dB(A) due to the operation of karting track, and therefore the
operation of LNG terminal will have insignificant contribution to the
cumulative noise level at the NSR N1.
The EIA
Report for the Emission Control Project at Castle Peak Power Station “B” Unit
(EIA-123/2006), which is under public inspection, has also been reviewed. Given that the Emission Control Project is
located at more than 3 km from the NSR N1, its operation will have
insignificant contribution to the cumulative noise level at the NSR N1.
The noise
associated with the operation of LNG terminal and other projects is therefore
not expected to give rise unacceptable environmental impacts.
5.7.1
Construction
Phase
The predicted
noise levels are low and below the daytime and night time criteria as a result
of the considerable separation distance and a hill located between the NSR
and the Project. Therefore,
mitigation measures are not required.
5.7.2
Operational
Phase
The predicted
noise levels are below the daytime and night time criteria as a result of the
considerable separation distance between the NSR and the Project. Therefore, mitigation measures are not
required.
5.8
Environmental monitoring and audit
5.8.1
Construction
Phase
Given the
compliance with the stipulated noise criterion, noise monitoring is not
anticipated to be required during the construction phase.
5.8.2
Operational
Phase
Given the
compliance with the stipulated noise criterion, noise monitoring is not
anticipated to be required during the operational phase.
No noise
sensitive receivers will be affected by the construction activities. Predicted construction noise levels at the
NSR, range from 35 – 44 dB(A), which are within the stipulated noise criterion
of 75 dB(A). In view of the
insignificant construction noise impact, mitigation measures are not
anticipated during the construction phase.
Based on the most
conservative case, the noise levels generated from the
equipment at the LNG Terminal have been predicted. Due to the large separation distance and a
hill located between the NSR and the noise source, the predicted operational
noise level is 33 dB(A), which is within daytime and night-time noise
criteria. Therefore mitigation measures
are not anticipated during the operational phase.
In view of the anticipated insignificant noise impact in both
construction and operational phases, noise monitoring work is considered to be
not necessary.