This Section
provides an evaluation of the potential noise impacts associated with
the construction and operation of the Project, including the associated works
and marine activities.
The
principal legislation relating to the control of construction noise due to the
Project is the EIAO. The 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 with reference made to Annex
13 of the EIAO-TM for the
guidelines of noise assessment.
The Noise Control Ordinance (NCO) (Cap. 400) also 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). 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 the use of powered mechanical equipment (PME) at the
construction work sites, details the procedures that should be adopted for the
assessment of noise from construction work other than percussive piling, the
issuing of Construction Noise Permits (CNP), and for determining whether or not
any such CNP is being complied with.
Under the EIAO, potential noise impact arising
from general construction works during non-restricted hours (i.e. 0700 to 1900
hours on any day not being a Sunday or public holiday) at noise sensitive uses
that rely on opened windows for ventilation, should be assessed in accordance
with the noise criteria specified in the EIAO-TM. The EIAO-TM noise standards are presented in Table 8.1.
Table 8.1 EIAO-TM Daytime Construction Noise Standards (Leq(30min)
dB(A))
Uses |
Noise
Standards (dB(A)) |
Domestic Premises |
75 |
Educational
Institutions |
70 |
Educational
Institutions (during examination periods) |
65 |
Notes: (a) The
above standards apply to uses which rely on opened windows for ventilation. (b) The
above standards shall be viewed as the maximum permissible noise levels
assessed at 1m from the external façade. |
When
assessing a CNP application for the use of PME during the restricted hours (i.e.
1900 to 0700 hours of the next day and any time on Sundays and public
holidays), the Noise Control Authority will compare the Acceptable Noise Levels
(ANLs), as promulgated in GW-TM, and the Corrected Noise Levels (CNLs)
(i.e. after accounting for factors such as barrier effects and reflections)
associated with the proposed PME operations.
The ANLs are related to the noise sensitivity of the area in question
and different Area Sensitivity Ratings (ASRs) have been established to reflect
the background characteristics of different areas. The appropriate ASR for the noise sensitive
receiver (NSR) is determined with reference to Table 8.2.
Table 8.2 Area Sensitivity Ratings (ASRs)
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)
"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. |
The
relevant ANLs are shown in Table 8.3.
Table 8.3 Acceptable Noise Levels of General Construction
Works
Time period |
LAeq
5min (dB(A)) |
||
ASR “A” |
ASR “B” |
ASR “C” |
|
All days during
the evening (i.e. 1900-2300 hours) and general holidays (including Sundays)
during the day and evening (i.e. 0700-2300 hours) |
60 |
65 |
70 |
All days
during the night-time (i.e. 2300-0700 hours of the next day) |
45 |
50 |
55 |
The Noise Control
Authority will consider a well-justified CNP application, for construction
works within restricted hours as guided by the relevant TMs issued under the
NCO. The Noise Control Authority will
take into account the adjoining land uses and any previous complaints against
construction activities at the site before making a decision. Nothing in this EIA Report shall bind the
Noise Control Authority in making its decision.
The Noise Control Authority may include any conditions in a CNP that it
considers appropriate. Failure to comply
with any such conditions may lead to cancellation of the CNP and prosecution
action under the NCO.
The EIAO-TM and the Technical
Memorandum for the Assessment of Noise from Places Other than Domestic Premises,
Public Places or Construction Sites (IND-TM) issued under the NCO specify the
applicable ANLs for the operation of Project.
The ANLs are dependent on the Area Sensitivity Rating (ASR) and the time
of the day as presented in Table 8.4. Each NSR 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.
Table 8.4 Acceptable Noise Levels (ANLs) of Operational
Noise
Time Period |
LAeq
30min (dB(A)) |
||
ASR “A” |
ASR “B” |
ASR “C” |
|
Daytime: 0700-1900 hrs
& Evening: 1900-2300 hrs |
60 |
65 |
70 |
Night-time: 2300-0700 |
50 |
55 |
60 |
Fixed plant
noise is controlled under Section 13 of the NCO
and the predictions will be undertaken in accordance with the IND-TM.
The noise criteria for planning and design of planned fixed noise
sources under Designated Projects are set out in the EIAO-TM as follows:
n
the noise level at the facade
of the nearest NSR is at least 5 dB(A) lower than the appropriate ANL (as shown
in Table
8.4) as specified in the IND-TM;
or
n
the prevailing background
noise level (for quiet areas with a noise level 5 dB(A) below the appropriate
ANL).
In accordance with the requirements
given in Section 3.4.8.2 and Clauses
2.2.1(a) and 3.2.1(a) in Appendix G of the EIA Study Brief, the Assessment
Area for the noise impact assessment should generally cover a distance of 300 m
from the boundary of the Project and the works of the Project. The Assessment Area considered in the
assessment is shown in Figure 8.1.
The Project site is located
about 200 m northeast of Plover Cove Country Park. The Project is located in a
relatively open sea area. Background
noise at the Project site and the surrounding environment is dominated by the prevailing
general background including sea waves.
The statutory Outline Zoning
Plans (OZP) and other relevant development plan available from Lands Department
or Town Planning Board have been reviewed with regard to the Assessment Area.
There is no existing OZP in the Assessment Area for the Project site. There is no committed and planned NSR
identified within the defined Assessment Area.
The identified representative NSRs are listed in Table 8.5 and shown in Figure 8.1. Photographs of the representative NSRs are shown
in Appendix 8A.
Table 8.5 Identified Representative NSRs
NSR
ID |
Description |
Use |
Approximate
Distance to nearest Project Site Boundary (m) |
N1 |
Outward
Bound Hong Kong – Wong Wan Chau Base |
Existing Educational |
710 |
N2 |
Plover
Cove Country Park |
Country
Park |
87 (a) |
N3 |
Plover
Cove (Extension) Country Park |
Country
Park |
273 (a) |
Note: (a)
The
areas of Plover Cove and Plover Cover (Extension) Country Parks within 300 m of
the Project are not accessible by any hiking trail due to steep slope. The nearest accessible hiking trail is more
than 300 m from the Project. |
As
mentioned in Section 2, the construction of the Project would take a few
weeks for the assembly and anchoring of each fish raft. No heavy PME is required and no noisy
activities will take place during the construction phase. All construction works will be carried out
during non-restricted hours only. The
main components of the fish rafts and cages will be manufactured off-site. The construction of the Project site will
mainly involve the following:
§ Towing of existing fish rafts from
other location(s) to the new FCZ using tug boat for a few trips a day and
anchoring; and
§ Assembly and anchoring of fish
rafts by winch;
Small
marine vessels such as sampans and speed boats could be present and used as
supporting vessels during the construction.
Anchoring of marine vessels could be required when positioning the fish
raft. The installation of the fish raft
mooring system would be conducted by attaching the anchor lines from the fish
rafts to anchoring points on the seabed.
No dredging works are required during the construction phase. Auxiliary facilities, such as storage and
shelters for fish farmers may be installed on some of the fish rafts. Details
of the construction plant inventory are presented in Appendix
8B. and it will be subject
to further design at later stage.
Mariculture
activities, such as management of fish raft / cages and fish stocks within the
Project site will be undertaken during operation phase. Limited numbers of small power generators
will be used on fish raft to support the daily mariculture activities. The transportation of fish stock, fish feed,
fish raft equipment and workforce as well as occasional visitors will occur
with the use of small marine vessels such as sampans and speed boats for a few
trips a day. No PA system or
loudspeaker will be used on-site during operation of the Project. No maintenance dredging or sediment removal
is anticipated during FCZ operation under the Project.
As
mentioned in Section 8.4.1, the construction of the Project would take a few
weeks for the assembly and anchoring of each fish raft. No heavy PME is required and no noisy
activities will take place during the construction phase. The main components of the fish rafts and cages
will be manufactured off-site. The
construction works are marine-based with limited air-borne noise impact, i.e.
installation of the fish raft mooring system and anchoring on the seabed.
NSRs N2 and
N3 for Country Parks are identified within the 300 m Assessment Area, however,
specific noise limit for Country Parks is not available from the relevant
legislation and guidelines, including EIAO-TM and GW-TM. The Country Parks only consist of limited
transient hikers, and the nearest designated campsite is more than 4 km away
from the Project Site. NSR N1 is located
at least 700 m away from the Project Site. In view of the small scale of the
Project with limited numbers of PME required for the construction and noisy
activities are not required, adverse noise impact during construction phase is
not anticipated.
As
mentioned in Table 8.5, the areas of Plover Cove and Plover Cover
(Extension) Country Parks within 300 m of the Project are not accessible by any
hiking trail due to steep slope. The
nearest accessible hiking trail is more than 300 m from the Project. The Country Parks only consist of limited
transient hikers, and the nearest designated campsite is more than 4 km away
from the Project Site. There is no specific operation phase noise criteria for
Country Parks in the relevant guidelines and TMs. NSR N1 is located at least
700 m away from the Project Site. With small number of marine vessel trips/day for transportation, limited
numbers of small power generators and no noisy operational activities within
the Project site, adverse noise impact due to operation of the Project is not
anticipated.
In
view of no adverse noise impact is anticipated due to the construction and operation
of the Project, mitigation measures are therefore not required for both
construction and operation phases.
Adverse residual impacts are not anticipated.
Although
adverse construction noise impact is not expected, Recommended Pollution Control Clauses for Construction Contracts issued
by EPD will be included in the Contract for future contractor(s) to
follow. Good construction site
practice and noise management could also be considered to reduce the noise
impact from the construction activities as follows:
§ Only well-maintained plant will be
operated on-site and plant will be serviced regularly during the construction
phase;
§ Silencers or mufflers on
construction equipment will be utilised and will be properly maintained during
the construction phase;
§ Mobile plant, if any, will be
sited as far away from NSRs as possible;
§ Machines and plant that may be in
intermittent use will be shut down between work periods or will be throttled
down to a minimum;
§ Plants known to emit noise
strongly in one direction will, wherever possible, be orientated so that the
noise is directed away from the nearby NSRs; and
§ Other structures will be
effectively utilised, wherever practicable, in screening noise from on-site
construction activities.
No
existing or committed project is identified in the vicinity of the Project
site. Cumulative impacts are therefore
not expected during both construction and operation phases of the Project.
No
adverse noise impacts are anticipated during construction and operation of the
Project. No environmental monitoring and
audit (EM&A) requirements related to noise are considered necessary during
both construction and operation phases.
The areas of Plover Cove and
Plover Cove (Extension) Country Parks within 300 m from the Project site are
not accessible by any hiking trail due to steep slope. The nearest accessible hiking trail is more
than 300 m from the Project. No specific
construction noise limit for Country Parks is available from the relevant
legislation and guidelines, including EIAO-TM
and GW-TM. The nearest representative NSR
is located at more than 700 m from the Project site. In view of the small scale
of the Project with limited numbers of marine vessel trips / day and noisy
activities are not required, adverse noise impacts
associated with the construction and operation of the Project are not
anticipated. Mitigation measures are
therefore not considered to be required.