This section provides an evaluation of the potential
noise impacts arising from the construction and operation of the proposed
Project at the Black Point Power Station (BPPS). Appropriate mitigation measures will be
recommended, where necessary, in order to mitigate any adverse impacts.
5.2
Relevant
Legislation & Assessment Criteria
5.2.1
Construction Phase
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.
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), which provides the
guidelines for controlling the construction noise from powered mechanical
equipment (PME) in general construction works, is applicable to the control of
noise impacts from the construction of this Project.
General Construction Works during Restricted Hours
The NCO
provides statutory controls on general construction works during restricted
hours (ie 1900 - 0700 hrs 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 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.
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) (ie 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, ie
A, B or C, see Table 5.1) 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 5.1.
Table 5.1 Area
Sensitivity Ratings
|
Types of Area Containing NSR |
Degree to which NSR is affected by
Influencing Factor (IF) |
||
|
|
Not Affected |
Indirectly
Affected |
Directly
Affected |
|
Rural area, including |
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) " (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. |
|||
The relevant ANLs
for each ASR are shown in Table 5.2.
Table 5.2 Acceptable Noise Levels (ANLs) for General Construction Works to be carried out
during Restricted Hours (GW-TM) (a)
|
Time period |
Area Sensitivity Rating Leq, 5 min (dB(A)) |
||
|
|
A |
B |
C |
|
All days during the evening (ie 1900-2300 hrs) and general holidays (including
Sundays) during the day and evening (ie 0700-2300
hrs) |
60 |
65 |
70 |
|
All days during the night-time (ie 2300-0700 hrs) |
45 |
50 |
55 |
|
Note: (a) The above standard applies to uses which
rely on opened windows for ventilation. |
|||
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.
General Construction Works during
The NCO does
not provide for the control of noise from construction activities during normal
working hours (0700 – 1900 hrs on any day not being a Sunday or public
holiday). However, as stipulated
under the EIAO, potential noise
impact arising from general construction works during these hours is to be
assessed in accordance with the noise criteria specified in Annex 5 of the EIAO-TM. The EIAO-TM noise standards are presented in
Table 5.3.
Table 5.3 EIAO-TM
Day-time Construction Noise Standards
|
Use |
Noise Standard Leq, 30 min (dB(A)) |
|
Domestic Premises |
75 |
|
Educational Institutions (normal periods) |
70 |
|
Educational Institutions (during examination periods) |
65 |
|
Notes: (1) The above standards apply to building
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. |
|
5.2.2
Operation Phase
Fixed plant noise associated with the operation of a
project is controlled under Section 13
of the NCO, and the Technical
Memorandum on Noise From Places Other than Domestic
Premises, Public Places or Construction Sites (IND-TM) specifies the
applicable ANLs for assessing potential operational
noise impacts. The noise standards
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 5.4) as specified in the 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 noise criteria 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 5.4.
Table 5.4 ANLs to be used as Operational Noise Criteria
|
Time Period |
Leq 30min (dB(A)) |
||
|
|
ASR “A” |
ASR “B” |
ASR “C” |
|
Day-time (0700 - 1900 hrs) |
60 (55) |
65 (60) |
70 (65) |
|
Evening (1900 - 2300 hrs) |
60 (55) |
65 (60) |
70 (65) |
|
Night-time (2300 - 0700 hrs) |
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 1.8 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, if any, located in the vicinity
of the proposed site.
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. Nothing in
this Report shall bind the Noise Control Authority in the context of law
enforcement against any fixed noise source being assessed.
5.3
Baseline
Environmental Conditions & Noise Sensitive Receivers
5.3.1
Baseline Environmental Conditions
Whilst the proposed reclamation is at the northern part
of the Black Point Power Station (BPPS), the proposed site for the co-located
Gas Receiving Station (GRS) is within the boundary of BPPS. The west of the proposed land-based site
is open sea. The background noise
environment is dominated by the fixed plant noise from the operation of the
BPPS and road traffic noise from
5.3.2
Noise Sensitive Receivers
In accordance with the requirements given in Clause 3.4.2.2 of the EIA Study Brief, the Study Area for the
noise impact assessment covered a distance of 300 m from the project
boundary. The area considered in
the assessment is shown in Figure 5.1. No existing NSR has been identified
within the Study Area, and no planned NSR has been identified within 2 km from
the Project Site. This applies to
both the proposed GRSs and submarine gas pipelines.
Since no NSR is identified, in agreement with Clause (i) of Section 3.4.2.2 of the EIA Study Brief, baseline noise
measurement to investigate existing noise levels is not deemed necessary.
5.4
Potential Sources of Impacts
In accordance with Clause 3.4.2.2 of the EIA
Study Brief, a Construction Noise Assessment is required for this EIA. There will be no plant emitting noise in
the GRSs,
hence significant noise associated with the operation of this Project is not
anticipated. Further operational
phase assessment is thus not necessary.
5.4.1
Construction Phase
Potential noise sources during the construction phase
of the Project will mainly arise from PME operating at the construction work
sites. The major construction work
will include the following key activities:
·
Land based works for co-located GRS at BPPS:
-
Minor site clearance;
·
Installation of Submarine gas pipelines.
·
Reclamation:
-
Dredging;
-
Seawall construction; and
-
Placing fill.
An
inventory of equipment for construction activities are summarised in Annex
5A. 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. No blasting works are anticipated.
The standard working hours will be from 0800 to 1800
hours. However, depending on the
location, the following works may be carried out during the evening or the
night-time periods:
·
Dredging
/ jetting; and
·
Installation
of gas pipelines.
It should be noted that the facility construction works for the GRSs will not be carried out during restricted hours. Should evening and night works between
1900 and 0700 hrs of the next day or on public holidays (including Sundays) be required,
the Contractor will submit a CNP application which will be assessed by the Noise Control Authority.
Findings of the detailed desktop review indicate that
no NSR was identified within the Study Area. Further quantitative assessment for
predicted noise levels at NSR was therefore not undertaken.
A noise impact assessment was conducted as part of
the HKLNG EIA to evaluate the potential noise impacts from the construction and
operation of submarine gas pipeline and GRS at BPPS ([1]).
Potential noise impacts to the NSR identified at the HKLNG EIA (village
house at Lung Kwu Sheung
Tan) were considered as insignificant since the predicted noise levels were
within the relevant noise criteria.
This village house does not lie within the Study Area for this
assessment and thus it is not considered under this Project.
Given the similarity in work nature and the plants to
be used for construction activities, potential noise impacts arising from this
Project are expected to be similar to those predicted in the approved HKLNG
EIA, which would be insignificant and acceptable.
5.5.1
Cumulative Impacts
At present the only known projects that are planned
to be constructed and operated in sufficient proximity of this Project is the
HKSAR Government’s Sludge Treatment Facilities which have been proposed to be
located at Tsang Tsui (i.e. east of the existing
CAPCO Ash Lagoon at Tsang Tsui and west of the WENT
Landfill), at > 1.2 km from the proposed reclamation and pipelines and the
extension to the WENT landfill.
Findings of the approved EIA Report for the Sludge
Treatment Facilities (AEIAR-129/2009) suggested that there would not be any
unacceptable noise impacts, including the off-site traffic noise impact along
In view of the insignificant potential noise impact,
mitigation measures are therefore not required. Residual impacts are not anticipated.
5.7
Environmental
Monitoring & Audit
Noise monitoring is not anticipated to be required
during the construction phase and operation phase of this Project.
Regular site inspections and audits will be carried
out during the construction phase in order to confirm that regulatory
requirements are being met and that contractors are implementing noise control
measures in accordance with contract conditions.
No NSR was identified within the Study Area. Potential noise impacts from the
construction and operation of this Project was assessed and it was considered
that potential noise impacts arising from the Project are expected to be
insignificant and acceptable.
Mitigation measures are therefore not required. Noise monitoring is also not considered
to be necessary.