8.
NOISE IMPACT
8.1
Background
8.1.1.1
The study area for the
potential noise impacts from the construction and operation of the proposed STF
is 300m from the boundary of the facilities. After carrying out detailed
desktop review and site survey, no noise sensitive receiver (NSR) was
identified within the study area. Hence no assessment was carried out for
the potential noise impacts from the construction and operation of the proposed
facilities.
8.1.1.2
However, during the
operation phase of the STF, extra traffic generated from trucks delivering
dewatered sludge to the proposed STF is anticipated. Assessment for the
potential off-site traffic noise impact at NSRs along
Lung Kwu
Tan Road is deemed necessary.
8.1.1.3
This section presents
the assessment for the potential off-site traffic noise impact at the NSRs and compares the traffic noise impact for scenarios
with and without the operation of the STF.
8.2
Traffic Noise Criteria under Environmental
Impact Assessment Ordinance
8.2.1.1
The potential noise
impact from the off-site traffic generated from the STF was assessed in
accordance with Annex 5 “Criteria for Evaluating Noise Impact” and Annex 13
“Guidelines for Noise Assessment” of the Technical Memorandum on Environmental
Impact Assessment Process (EIAO-TM). Annex 5 of the EIAO-TM defines the
criteria L10 (1 hour) for road traffic noise at various NSRs:
l 70 dB(A) at
the façades of dwellings, hotels, offices;
l 65 dB(A) at
the façades of schools, places of public worship, courts of law, place where
unaided voice communication is required; and
l 55 dB(A) at
the façades of hospital.
8.2.1.2
In the case of any
façades of NSRs are exposed to predicted noise levels
exceeding the relevant noise criteria and noise induced by the proposed STF
contribute significantly to the overall traffic noise level by 1.0 dB(A) or more, direct mitigation measures shall be proposed.
8.3
Assessment Area
8.3.1.1
The assessment area for
the off-site traffic noise is the area within 300m from the curb side of the Lung Kwu Tan Road
from Castle Peak Power Station A to Lung Kwu Sheung Tan. Other than the small portion of the area
close to the Power Station zoned as Open Space and Green Belt, the remaining
portion of the assessment area is currently with no zoning in the Outline
Zoning Plan. The location of the assessment area is shown in Figure 8.3.
8.4
Existing and Planned Sensitive Receivers
8.4.1.1
In accordance with
Annex 13 of the EIAO-TM, 4 numbers of representative NSRs
were identified along Lung Kwu Tan Road for this traffic
noise impact assessment. All of these representative NSRs
are located in the area with no zoning.
8.4.1.2
No statutory planned
use in the area is known currently. Many land lots within the assessment
area are privately owned. Some land lots are with existing buildings and
some are vacant lands. Should a land owner wish to construct a building within
his/her land lots, he/she has to apply for a building licence from the Lands
Department. The permission of the application is subject to the decision of the Lands Department.
8.4.1.3
In view of this
situation, there is a potential that new sensitive receivers would exist in the
assessment area at any time. However, as the existing NSRs
are already located in close proximity along Lung Kwu Tan Road,
future NSR, if any, should be in a similar condition of traffic noise exposure.
8.4.1.4
Representative NSRs were selected for the assessment and agreement with
the authority was sought. The details of the NSRs
are given in Table 8.1.
Table 8.1
Summary of Representative Noise Sensitive Receivers
NSR
ID
|
Description
|
Use
|
No.
of Floors
|
N1
|
Village house No.314 at Lung
Tsai
|
Residential
|
3
|
N2
|
Village house No.177 at Sha Po Kong
|
Residential
|
3
|
N3
|
Village house No.23 at Pak
Long
|
Residential
|
3
|
N4
|
Tin Hau Temple at Pak Long
|
Place of public worship
|
1
|
8.4.1.5
The relative locations
of the STF and the NSRs are shown in Figure 8.1. The photos of the
representative NSRs are provided in Appendix 8.1. The
approximate horizontal distances between the proposed STF and Lung Kwu Tang Road
to the representative NSRs are given in Table 8.2.
Detailed locations of the NSRs are shown in Figure 8.2a and 8.2b.
Table 8.2
Horizontal Distance from STF and Lung
Kwu Tang Road to
Representative Noise Sensitive Receivers
NSR
ID
|
Distance
from Proposed STF, km
|
Distance
from Lung Kwu
Tang Road (near kerb), m
|
N1
|
4.0
|
21
|
N2
|
3.8
|
20
|
N3
|
3.5
|
11
|
N4
|
3.5
|
27
|
8.5
Assessment Methodology
8.5.1.1
The peak hour traffic
flow of the maximum traffic projection within a 15 year period upon
commencement of the Project was adopted for the traffic noise prediction.
The projected year of the maximum flow was determined to be 2027. Two
scenarios i.e. with and without the operation of the proposed STF in 2027 were
studied.
8.5.1.2
In order to have a
better understanding of the potential off-site traffic noise impact, the
prevailing scenario i.e. 2012 before commencement of the proposed STF was
studied. The predicted peak hour traffic flows of the three scenarios are
summarized in Table 8.3. The traffic flows adopted
has been endorsed by the Transport Department.
Table 8.3 Projected Peak
Hour Off-site Traffic Flow
Road
section
|
Prevailing
2012 Without STF (veh/hr)
|
Year
2027
|
Without
STF
(veh/hr)
|
With
STF
(veh/hr)
|
Lung Kwu
Tan Road (section from Lung Fai Street to Public Bus terminal
at Pak Long)
|
400 (59%)
|
650 (60%)
|
680 (62%)
|
Lung Kwu
Tan Road (section from Public Bus terminal at
Pak Long to Yung Long Road)
|
240 (74%)
|
420 (72%)
|
440 (73%)
|
Note: The figures in brackets
represent the percentage heavy vehicle.
8.5.1.3
As there is no noise screening structure along Lung Kwu
Tan Road in front of the NSRs, the first floor (the
most affected level) of the NSRs is used for carrying
out the prediction. Traffic noise levels at representative NSRs were predicted and evaluated against the assessment
criterion. The noise prediction was carried out using the in-house
computer noise model, which is based on the UK Department of Transport’s
Calculation of Road Traffic Noise (CRTN) procedures.
8.6
Evaluation of Potential Traffic Noise Impact
8.6.1.1
The potential traffic
noise impact at representative NSRs was assessed
based on the three traffic scenarios. Table 8.4
summarized the predicted road traffic noise levels at the representative NSRs for the 2012 prevailing scenario and the 2027 without
STF operation scenario.
Table 8.4
Predicted Noise Levels at Representative NSRs
NSR ID
|
Assessment level
|
Assessment Criteria, dB(A)
|
Predicted noise levels,
dB(A)
|
2012
Prevailing
|
2027
Without STF
|
N1
|
1/F
|
70
|
72.5
|
74.7
|
N2
|
1/F
|
70
|
73.0
|
75.2
|
N3
|
1/F
|
70
|
73.7
|
76.0
|
N4
|
1/F
|
65
|
70.4
|
72.7
|
8.6.1.2
As revealed from the
assessment results shown in Table 8.4, the predicted traffic noise levels at all
representative NSRs for both the 2012 prevailing
scenario and the 2027 without STF operation scenario would exceed the noise
criteria stipulated in the EIAO-TM.
8.6.1.3
Table 8.5
summarized the predicted road traffic noise levels at the representative NSRs for the 2027 with and without STF operation scenarios.
Table 8.5
Predicted Noise Levels at Representative NSRs in 2027
NSR ID
|
Assessment level
|
Predicted Noise Levels, dB(A)
|
Difference, dB(A)
|
Without STF (1)
|
With STF (2)
|
(2) – (1)
|
N1
|
1/F
|
74.7
|
75.0
|
0.3
|
N2
|
1/F
|
75.2
|
75.5
|
0.3
|
N3
|
1/F
|
76.0
|
76.3
|
0.3
|
N4
|
1/F
|
72.7
|
73.0
|
0.3
|
8.6.1.4
For the 2027 with STF
operation scenario, as shown in the assessment results, the changes in noise
levels due to the induced traffic would be +0.3 dB(A). Since the changes
in predicted noise levels are all well below 1 dB(A), the potential off-site
traffic noise impact on the identified NSRs due to
the operation of the proposed STF would be considered insignificant.
8.7
Conclusions
8.7.1.1
The assessment focused
on the traffic noise impact due to the off-site traffic generated from the
operation of the proposed STF. A traffic noise impact assessment was
carried out for the prevailing scenario (Year 2012 before commencement of the
proposed STF) and scenarios with and without the operation of the STF in 2027.
8.7.1.2
Assessment results
indicated that the predicted traffic noise due to the off-site traffic
generated from the proposed STF would not result in significant increase in
traffic noise impact on the NSRs along Lung Kwu Tan Road.