This Section presents the
potential noise impacts associated with the site levelling, track paving and
the noise impacts associated with maintenance and operation of the Project.
The principal legislation relating
to the control of construction noise is the Noise
Control Ordinance (Cap. 400) (NCO). Various Technical Memoranda (TMs), which stipulate control approaches and criteria, have
been issued under the NCO.
The following TMs are applicable to the control
of noise from construction activities:
·
Technical
Memorandum on Noise from Construction Work other than Percussive Piling (GW-TM);
and
·
Technical
Memorandum on Noise from Construction Work in Designated Areas (DA-TM).
Apart
from the above, the Environmental Impact
Assessment Ordinance (EIAO) (Cap. 499) also provides means to assess
construction noise impacts. The Technical Memorandum on Environmental Impact
Assessment Process (EIAO-TM),
issued under the EIAO, provides
guidelines and noise criteria for evaluating construction noise impacts.
Under the EIAO, noise impact arising from general construction works during
normal working hours (i.e. 0700 to 1900 hours on any day not being a Sunday or
public holiday) at the openable windows of buildings
is to be assessed in accordance with the noise criteria as given in the EIAO-TM. The EIAO-TM
noise standards are presented in Table
5.1.
Table 5.1 EIAO-TM
Daytime Construction Noise Standard (Leq,
30 min dB(A))
Use |
Noise
Standard |
Domestic Premises |
75 |
Educational Institutions (normal periods) Educational Institutions (during examination periods) |
70 65 |
When
assessing a CNP application for the use of Powered Mechanical Equipment (PME)
during restricted hours, the Noise Control Authority will compare the ANLs, as promulgated in GW-TM, and the CNLs (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 have been established to reflect the background
characteristics of different areas.
The relevant ANLs are shown in Table 5.2.
The Noise
Control Authority will consider a well-justified Construction Noise Permit
(CNP) application, once filed, 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 in granting a CNP. Nothing in this EIA Report shall bind
the Noise Control Authority in making his 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.
Table 5.2 Acceptable
Noise Levels (ANL, Leq, 5 min dB(A))
Time
period |
Area
Sensitivity Rating |
||
|
A |
B |
C |
All days during
the evening (1900-2300 hours) and general holidays (including Sundays) during
the day and evening (0700-2300 hours) |
60 |
65 |
70 |
All days
during the night-time (2300-0700 hours) |
45 |
50 |
55 |
In addition to the general controls
on the use of PME during restricted hours, the EPD has implemented a more
stringent scheme via the DA-TM.
The DA-TM regulates the use of five types of Specified Powered
Mechanical Equipment (SPME) and three types of Prescribed Construction Work (PCW),
which are non-PME activities, in primarily densely populated neighbourhoods
called Designated Areas (DAs). The
SPME and PCW are:
SPME:
·
hand-held breaker;
·
bulldozer;
·
concrete lorry mixer;
·
dump truck; and
·
hand-held
vibratory poker.
PCW:
·
erection or dismantling of formwork or
scaffolding;
·
loading, unloading or handling of
rubble, wooden boards, steel bars, wood or scaffolding material; and
·
hammering.
A CNP will be required for works
during the time between 1900 and 0700 hours and any time on a general holiday,
including Sunday, and the noise criteria for evaluating noise impact laid down
in relevant TM issued under the NCO must be met.
As the Study Area is located
outside a designated area, the noise criteria stipulated under the DA-TM are
not applicable in this Study.
The EIAO-TM
and Technical Memorandum on Noise From Places Other
than Domestic Premises, Public Places or Construction Sites (IND-TM)
specifies the applicable Acceptable Noise Levels (ANLs)
for operational noise of the karting track. The ANLs are
dependent on the Area Sensitivity Rating (ASR) and the time of the day and are
presented in Table 5.3.
Table 5.3 ANLs to be used as Operation Noise Criteria
Time Period |
LAeq 30min (dB(A)) |
||
ASR “A” |
ASR “B” |
ASR “C” |
|
Daytime 0700-1900 |
60 |
65 |
70 |
Evening 1900-2300 |
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 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 5.3)
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 are dependent on the Area
Sensitivity Rating (ASR) of the NSRs as shown in Table
5.3.
In any event,
the Area Sensitive Rating assumed in this Report is for indicative assessment
only given that there are currently no influencing factors assumed in the
vicinity of the NSRs. 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 all
the fixed noise sources being assessed in this report.
The
proposed karting track is located at Lung Kwu Sheung Tan which is rural in
nature and is characterised predominantly industrial uses. The existing land uses to the west of
the site are open storage of powered mechanical equipment, plastics recycling
factories, concrete batching plant and dangerous goods stores. The site is currently approximately 5 mPD, which is
lower than the level of
Background
noise is dominated by the traffic noise from
As discussed in Section 5.3.1, the proposed site
included an existing village house and a Tsz
Tong. The Tsz
Tong will be kept without any modification and will only be used by the Lau’s family members of Lung Kwu
Tan village for private functions and unauthorized public entry is
strictly prohibited, and therefore Tsz Tong is not
considered as a public place of worship.
In view that the Tsz Tong will not be used by
any public at any time, for the purpose of this EIA, the Tsz
Tong has not been identified as a NSR.
Agreement has been made between
the land owner and the Project Proponent that the proposed site (including the
village house to be used as an office) will be leased to the Project Proponent
for the development of an outdoor karting track. The village house within the site
boundary will be used as an office for the karting
track only. Residential use is not
permitted at the village house while the land is used as an outdoor karting track. The
Project Proponent also confirmed that the village house will only be used as an
office of the karting track. In view that the village house will not
be used as residential purpose during the karting
track leasing period, for the purpose of this EIA, the village house has not
been identified as a NSR. However, should this village house is to be used for residential purpose
during the operation of the karting track, mitigation
measures are proposed in order to attenuate the noise impact (see Annex B).
A land search has been conducted
to identify any existing NSRs within 300 m from the Study Area boundary. Three ruined and vacant building
structures were observed to be located to the west of site during the
search. During a site visit, it has
been identified that these structures have been converted as a canteen and
located within the industrial area and therefore these village houses have not
been identified as a NSR. However,
should these building structures are used for residential purpose, in view of
the large separation distance, noise impacts
associated with the karting track is not expected.
In addition, as confirmed with
the District Lands Office (DLO), there are no planned residential uses
identified within the Study Area.
It has been identified during
site visit that the industrial area located to the west of
the Site are used for open storage, plastics recycling factories and
canteens for the workers in the vicinity.
The nearest residential uses have
been identified as the village house at Pak Long located at about 1153m from
the southern site boundary. The
locations of the identified NSRs are shown in Figure 5.1. No planned NSRs
are identified in the study boundary.
A noise survey was conducted in
22nd July 2005 to investigate the existing acoustic condition at the
identified NSRs.
The background in Pak Long was dominated by the road traffic noise from
Lung Kwu Tan Road, and the measured daytime noise
level Leq, 15min at the NSR was
54.9 dB(A).
As the site is
located in a rural area and no influencing factors affect the NSRs, an ASR “A” has been assumed for the NSRs located at Pak Long. As the measured prevailing noise level
was lower than the (ANL-5) criterion, and therefore the criterion, i.e. 54.9 dB(A) LAeq, 30min
for daytime period will be considered as the stipulated noise limit for the
assessment of operational noise impact.
Table 5.4 Identified
Noise Sensitive Receivers
NSR |
Location |
Type
of Uses |
|
N1 |
No. 32 Pak Long |
Residential (3-Storey) |
|
The
major construction activities associated with the Project that may cause noise
impacts to the NSRs are:
·
Excavation and compaction works for forming
levelled ground; and
·
Track Paving.
The
construction period of the Project will take approximate 2 months. In addition, the construction works for
site leveling and track paving will be carried out in phases without
overlapping according to planned project programme,
i.e. track paving will be carried out after completion of Site Formation.
The
use of PME during the construction phase will be the main source of noise
impact. The use of PMEs such as bulldozer, excavator, dump truck, asphalt paver and road roller will be involved in the construction
activities.
Annex
A presents a detailed list of PMEs,
which are provided by the Project Proponent, assumed for each construction
activity considered in the noise impact assessment. Project Proponent has confirmed that the
plant inventory is practicable for the construction of karting
track.
The
normal working hours of the contractor will be between 07:00 and 19:00 hours
from Monday to Saturday (except public holidays) and construction activities
during restricted hours are not expected.
Should evening and night works between 19:00 and 07:00 hours or on
public holidays (including Sunday) be required, the contractor should submit a
CNP application and will be assessed by the Noise Control Authority. Conditions stipulated in CNPs should be strictly followed.
The design of the karting track will meet
international standard for kart racing and safety standard, and will only serve
members of the Hong Kong Kart Club for sporting purposes. In addition, the proposed karting track will be used for training or local racing
events. It should be iterated that
there will be no international events to be carried out at the proposed
track.
The karts to be running on the track are powered by Rotax
Max FR125 2-stroke single cylinder engines with displacement of 125c.c. As given in the technical specification
of the kart, the exhaust system is provided with intake silencer for reduction
of noise from exhaust system. The
major noise sources during the operational phase are therefore identified as
kart movement and public address (PA).
The karting track will operated from Monday to
Sunday with operating hours from 09:30 to 19:00 hours. The maximum number of karts to be
allowed to run on the track is 40 at any time. In addition, for a conservative
assessment, each run with up to 40 karts on the track is assumed to last for a
full 30 minutes during any half hour.
Project Proponent has also confirmed to maintain a maximum number of 200
visitors on site at any time. To
control the number of visitors and traffic generation, a 45-person
bus would run every hour between Tuen Mun Town Centre and the karting
track for transportation of the guest and participants, and there will be
around 10 bus trips per day. In
addition, no
on-site parking facility/area will be provided at the proposed karting track for minimizing traffic generation and there
are no parking facility /area located in the vicinity of the proposed site, it
is anticipated that small number of visitors may drive to the site. In view of the
small number of traffic induced on the existing road traffic, it is anticipated
that induced traffic noise would not pose adverse impact to the NSRs in Lung Kwu Sheung Tan.
Only minor maintenance works will
be carried out within the site so as to ensure the karts operate properly. In addition, only external repair will
be undertaken at site (ie replacement of
bodywork). Any engine maintenance
work will not be carried on site.
If such works are required, the vehicle will be
transport to a
garage for such repair.
The PA system at the karting track will be similar to the PA system at Kartodromo de Coloane,
however the project size of karting track is smaller
than Kartodromo de Coloane,
and therefore the power and number of speakers at the karting
track will be smaller that at Kartodromo de Coloane. It is
assumed that a total of 5 sets of PA system (each with 2 speakers) will be
provided within karting track.
Noise measurement has been
conducted for a kart racing on 27 November 2005 in the Kartodromo
de Coloane at
Broadband
measurement of LAeq, L10, L90, Lmax
and Lmin has been recorded at 500ms
interval to capture the noise
emissions from karts moving in high speed in front of sound level meter. At least 5 minutes measurement was
conducted at different locations along the track in order to collect noise data from
different kart movements inclusion of tyre noise,
skidding noise and braking noise.
To allow a conservative assessment, the highest Leq,5 min among different kart movements has been taken
to predict the sound pressure level at the identified NSRs. A summary of the noise measurement
results is presented in Table 5.5. Annex B presents the Leq, 500ms
time history measured at the different measurement locations.
As PA system at the karting track will be similar to the PA system at Kartodromo de Coloane, noise
measurement was also conducted for the PA system during announcement period
only and the measured Leq, 8 sec
at 3m from the PA system (with two speakers) is 86.2 dB(A). The sound power level of the PA system
is 104 dB(A).
The PA system was used occasionally and it is assumed that the PA system
will be used 5 minutes in every 30 minutes.
Table 5.5 Summary
of Noise Measurement for Kart Track Operation
Source |
Distance from source, m |
Leq, 5 min(1)(2), dB(A) |
Calculated Leq, 5 min at 1 meter , dB(A) |
Remarks |
|
Kart Movement (13 karts running at high
speed) |
3 |
85.2 |
94.7 |
Measurement taken in front of a straight
section of the track |
|
|
2.5 |
82.6 |
90.6 |
Measurement taken in front of a 90° turning section |
|
|
5 |
84.2 |
98.2 |
Measurement taken in front of a 120° turning section |
|
|
4 |
85.1 |
97.1 |
Measurement taken in front of a 180° turning section |
|
Remarks: 1) Noise measurement was conducted with reference to the calibration and
measurement procedures as stated in the Technical
Memorandum for the Assessment of Noise from Places other than Domestic
Premises, Public Places or Construction Sites (IND-TM). Immediately prior to and following
each noise measurement the accuracy of the monitoring equipment was checked
using an acoustic calibrator generating a known sound pressure level at a
known frequency. Measurements
were accepted as the calibration level from before and after the noise
measurement agree to within 1.0 dB.
Noise measurements were made without the presence of fog and rain, and
with steady wind speed and gusts not exceeding 5m/s and 10m/s, respectively. 2) The background noise
levels are in the range of 46 - 54dB(A), and
therefore the influence of background noise will not be included in the
measurement results. |
Based on the measured noise data from a kart
racing, the measured noise levels show regular pattern over the measured time period,
and therefore the measured Leq,5 min
represents a 30-minute continuous kart movement. In addition, for a conservative assessment, the maximum Leq,5
min of 98.2 dB(A) for the 13-kart movement will be adopted in the
prediction of operational noise impact.
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. In general, the methodology is as
follows:
·
locate representative NSRs that may be affected by the works;
·
determine the plant teams for
corresponding activities, based on agreed plant inventories;
·
assign sound power levels (SWLs) to the PME proposed based on the GW-TM or
other sources;
·
calculate the correction factors based
on the distance between the NSRs and the notional
noise source position of the work sites;
·
apply corrections in the calculations
such as potential screening effects and acoustic reflection, if any; and
·
predict
the construction noise levels at NSRs in the absence
of any mitigation measures.
The total SWL associated with
each activity was based on an assumed plant inventory, agreed with the Project
Proponent. The notional source
position of the work site was established in accordance with the procedures
stated in the GW-TM. Noise
impacts at NSRs were subsequently evaluated by
comparing the predicted noise levels with the EIAO-TM daytime construction noise limits (Leq,
30min dB(A)), as outlined in Section 5.2.1.
The methodology for the noise
impact assessment is in accordance with the procedures outlined in the IND-TM, which is issued under the NCO
and the EIAO-TM. The assessment will take into account the
distance attenuation, barrier attenuation and corrections of operation mode in
accordance with the IND-TM.
To assess the worst-case noise
impact from the karting track, the maximum noise
emission of the kart has been taken in the assessment.
Based on the notional source position
as identified in accordance with the procedures stated in the GW-TM, the
source-to-NSR distances are presented in Table
5.6.
Table 5.6 Noise
Sensitive Receivers
NSR |
Location |
Approx. Horizontal
Distance to Source (m) |
N1 |
No. 32 Pak Long |
1153 |
Based on existing topography, the
NSRs do not have direct line of sight to the
construction site. Therefore, with
reference to the GM-TM, a negative correction of 10 dB(A)
has been included in the construction noise assessment.
Without the use of mitigation
measures, predicted construction noise levels at all NSRs
during all construction stages will comply with the stipulated criterion. Details of the calculations are presented
in Annex A. A summary of the
construction noise levels is presented in Table 5.7. As confirmed by the Project Proponent,
there will not be overlapping periods between each construction
activities. Hence cumulative noise
impact during the construction period will not be a concern. Given that the predicted construction
noise levels are well within the stipulated noise criterion, mitigation
measures are not required to alleviate the noise impacts.
Table 5.7 Construction
Noise Levels - Unmitigated (Leq, 30
min dB(A))
|
Construction Noise Levels at
Different Stages, Leq, 30 min dB(A) |
|
NSRs |
Site Formation |
Track Paving |
N1 |
37 |
35 |
Based on the maximum sound pressure level of Leq,
5min 98.2 dB(A) at 1m for 13-kart movement, the
facade noise levels at the identified NSRs are
predicted and summarised in Table 5.8. Results indicate that the nearest NSR
(N1), which are shielded by the existing topography, will be subject to noise
level of 35 dB(A). Details of the
calculations are presented in Annex B.
Table 5.8 Predicted
Facade Noise Levels at NSRs
NSRs |
Description
|
Predicted Facade
Noise Level, dB(A) |
N1 |
No. 32 Pak Long |
35 |
Results indicated that the
predicted facade noise levels will comply with the day-time (ANL-5) noise
criterion of 55 dB(A) at all NSRs.
Though the predicted construction
noise levels comply with the stipulated noise criterion, good site practice and
noise management is recommended for minimising the construction noise impact on
nearby NSRs, including:
·
Only well-maintained plant should be
operated on-site and plant should be serviced regularly during the construction
works;
·
Machines and plant that may be use
intermittently, such as vibratory poker, should be shut down between work
periods or should be throttled down to a minimum;
·
Plant known to emit noise strongly in
one direction, should, where possible, be orientated to direct noise away from
nearby NSRs; and
·
Mobile plant should be sited as far
away from NSRs as possible.
The noise assessment indicated
that based on the maximum sound pressure level of 98 dB(A) at 1 m for 13-kart
movement, the predicted facade noise levels for a maximum of 40-kart event will
comply with the day-time noise criterion at the nearest NSRs. No mitigation measures are required.
Given the compliance with the
stipulated noise criterion, noise monitoring is not required during the
construction stage.
Given the compliance with the
stipulated noise criterion, noise monitoring is not required during the
operation stage.
Due to the large separation
distances, unmitigated construction activities associated with the Project will
not cause adverse noise impact at the NSRs. The predicted construction noise levels
are in the range of 35 – 37 dB(A), which complied with
the stipulated noise criterion.
Based on the worst case scenario
by adopting a maximum sound pressure level of 98 dB(A) at 1 m for 13-kart
movement, the predicted facade noise levels for a maximum of 40-kart event is
well below the daytime noise criterion of 55 dB(A) at all NSRs
located at more than 1km from the site boundary.
Given the NSRs
located at more than 1km and the compliance with the stipulated noise criteria,
noise monitoring during the construction and operational phase is not required.