3.1.1.1
This section presents the assessment on potential
air quality impacts arising from construction and operation of the Project,
which has been conducted in accordance with the criteria and guidelines as
stated in Section 1 of Annex 4 and Annex 12 of the Technical Memorandum on
Environmental Impact Assessment Process (EIAO-TM) as well as the
requirements given in Clause 3.4.4 and Appendix B of the EIA Study Brief (No.
ESB-319/2019).
·
Air
Pollution Control Ordinance (APCO) (Cap. 311) - this provides the power for
controlling air pollutants from a variety of stationary and mobile sources and
encompasses a number of Air Quality Objectives (AQOs);
·
Air Pollution Control (Construction Dust)
Regulation;
·
Air Pollution Control (Non-road Mobile
Machinery) (Emission) Regulation;
·
Air Pollution Control (Fuel Restriction)
Regulation; and
·
Environmental Impact Assessment Ordinance (EIAO)
(Cap. 499), EIAO-TM, Annex 4 and Annex 12.
Air Quality Objectives
3.2.1.2
The new set of AQOs which came into effect on 1
January 2022, is tabulated in Table 3.1.
Table
3.1 New Hong Kong Air Quality Objectives
|
Pollutant
|
Averaging Time
|
Concentration Limit, µg/m3 [1]
|
No. of Exceedances Allowed per Year
|
|
Fine Suspended Particulates
(PM2.5 / FSP) [3]
|
24-hour
|
50
|
18
[5]
|
|
Annual
[2]
|
25
|
Not
applicable
|
|
Respirable Suspended Particulates (PM10
/ RSP) [4]
|
24-hour
|
100
|
9
|
|
Annual
[2]
|
50
|
Not
applicable
|
|
Sulphur Dioxide (SO2)
|
10-minute
|
500
|
3
|
|
24-hour
|
50
|
3
|
|
Nitrogen Dioxide (NO2)
|
1-hour
|
200
|
18
|
|
Annual
[2]
|
40
|
Not
applicable
|
|
Photochemical Oxidants
[as Ozone (O3)]
|
8-hour
|
160
|
9
|
|
Carbon Monoxide (CO)
|
1-hour
|
30,000
|
0
|
|
8-hour
|
10,000
|
0
|
|
Lead (Pb)
|
Annual
[2]
|
0.5
|
Not
applicable
|
Notes:
[1] All measurements of the concentration of gaseous air
pollutants, i.e., sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide,
are to be adjusted to a reference temperature of 293 Kelvin and a reference
pressure of 101.325 kilopascal.
[2] Arithmetic mean.
[3] “Fine suspended particulates” means suspended
particles in air with a nominal aerodynamic diameter of 2.5 µm or less.
[4] “Respirable suspended particulates” means suspended
particles in air with a nominal aerodynamic diameter of 10 µm or less.
[5] Under the new AQOs,
the number of exceedances allowed per year for daily FSP is 35 times. However, for new government projects, the
number of exceedances allowed per year for daily FSP is 18 times only.
Air Pollution Control (Construction Dust) Regulation
3.2.1.3
With reference to the Air Pollution Control
(Construction Dust) Regulation, it specifies processes that require special
dust control. The Contractors are
required to inform the EPD and adopt proper dust suppression measures while
carrying out “Notifiable Works” (which requires prior notification by the Regulation)
and “Regulatory Works” to meet the requirements as defined under the Regulation.
Air Pollution Control (Non-road Mobile
Machinery) (Emission) Regulation
3.2.1.4
The Air Pollution Control (Non-road Mobile
Machinery) (Emission) Regulation comes into operation on 1 June 2015. Under the Regulation, non-road mobile
machinery (NRMMs), except those exempted, are required to comply with the
prescribed emission standards. From 1
September 2015, all regulated machines sold or leased for use in Hong Kong must
be approved or exempted with a proper label in a prescribed format issued by
EPD. Starting from 1 December 2015, only
approved or exempted NRMMs with a proper label are allowed to be used in
specified activities and locations including construction sites. The Contractor is required to ensure the
adopted machines or non-road vehicle under the Project could meet the
prescribed emission standards and requirement.
Air Pollution Control (Fuel Restriction)
Regulation
3.2.1.5
Air Pollution Control (Fuel Restriction)
Regulations should also be complied with an aim to prohibit the use of high
sulphur content solid and liquid fuel for commercial and industrial
appliances. The Project site is located
within the “Sha Tin Fuel Restriction Area” under the Air Pollution Control (Fuel Restriction)
Regulations. Except for construction
site or during emergency, only gaseous fuel is allowed to be used in the Sha
Tin Fuel Restriction Area. For any
fuel-using equipment that is used or operated in construction site or during
emergency in Sha Tin Fuel Restriction Area, Ultra Low Sulphur Diesel (ULSD) is
practically the liquid fuel to be used.
EIAO-TM
3.2.1.6
Annex 4 of EIAO-TM stipulates that hourly
Total Suspended Particulate (TSP) level should not exceed 500µg/m³ measured at
298 K and 101.325 kPa (one atmosphere) for the construction dust impact
assessment. It also stipulates that the
odour level at air sensitive receiver should meet 5 odour units based on an
averaging time of 5 seconds for odour prediction assessment.
3.2.1.7
Guidelines for conducting air quality assessment
are stipulated in Annex 12 of EIAO-TM, including the determination of air
sensitive receivers (ASRs), the assessment methodology, baseline study and
impact prediction and assessment.
3.3.1.1
The Project is to revitalise the existing Fo Tan Nullah (FTN) with
an aim to enhance the ecological value of the nullah, provide a greener
environment, promote water friendliness and improve the community
environment. The potential construction
phase air quality impacts from the Project would likely be dust impacts,
gaseous emissions from Powered Mechanical Equipment (PMEs), and potential odour
emission from excavated / desilted materials during excavation works at nullah
bed /desilting works at downstream tidal zone; while the potential operational
phase air quality impacts from the Project would likely be potential odour
emission from desilted materials during maintenance desilting works.
3.3.1.2
The Project site covers the existing FTN, which
is approximately 1.7 kilometres (km) long and 10 to 35 metres (m) wide, located
at the centre of Fo Tan District and is mainly surrounded by industrial
buildings on its upper portion and residential developments on its lower
portion, as illustrated in Figure 3.1.
3.3.1.3
The dominant existing air emission source within
500m assessment area from the Project area is vehicular emission from Fo Tan
Road, Tai Po Road (Shatin) and Sha Tin Road.
Within the 500m assessment area, there
was no chimney emission sources identified except that one specified process
(SP) under the APCO, Electricity Works (i.e. an Emergency Generator) located at
the PCCW Fo Tan Data Centre, was identified at the
time of the assessment. As its emission
is controlled under the SP licence and the generator is for emergency use only,
no adverse air quality impact arising from this SP is anticipated.
3.3.1.4
The nearest EPD general air quality monitoring
station to the Project area is situated at Sha Tin Government Secondary
School. The recent 5-year (between 2016
and 2020) concentrations of air pollutants measured at the monitoring station
relevant to the Project, including Fine Suspended Particulates (FSP),
Respirable Suspended Particulates (RSP), Sulphur Dioxide (SO2) and
Nitrogen Dioxide (NO2), were extracted and are summarised in Table 3.2. It is observed that the maximum 24-hour
average FSP concentrations and the 10th highest 24-hour average FSP concentrations
in the latest 5 years complied with the prevailing AQO. For RSP, non-compliance of the maximum
24-hour average concentrations were noted in Year 2016 to Year 2018 but the 10th
highest values in Years 2016 to 2020 all complied with the prevailing AQO. Both annual average FSP and RSP
concentrations, 10-minutes and 24-hour average SO2, hourly and
annual average NO2 complied with prevailing AQOs. In general, the results showed that there was
a decreasing trend in the pollutants levels in the past 5 years.
Table 3.2 Average Concentrations of
Pollutants in the Recent Five Years (Year 2016 – 2020) at Sha Tin EPD Air
Quality Monitoring Station
|
Pollutant
|
Averaging Time
|
Prevailing
AQO [1]
|
Data Summary
|
Year [2]
|
|
2016
|
2017
|
2018
|
2019
|
2020
|
|
Fine Suspended
Particulates (FSP)
|
24-hr
|
75 (9)
|
Max.
|
62
|
90
|
70
|
64
|
56
|
|
10th Max.
|
44
|
54
|
40
|
39
|
32
|
|
No. of Exceedance(s)
|
0
|
1
|
0
|
0
|
0
|
|
Annual
|
35
|
-
|
20
|
21
|
19
|
17
|
15
|
|
Respirable Suspended
Particulates (RSP)
|
24-hr
|
100 (9)
|
Max.
|
102
|
103
|
102
|
97
|
71
|
|
10th Max.
|
66
|
72
|
65
|
60
|
54
|
|
No. of Exceedance(s)
|
2
|
1
|
1
|
0
|
0
|
|
Annual
|
50
|
-
|
29
|
31
|
32
|
28
|
25
|
|
Sulphur Dioxide (SO2)
|
10-min
|
500 (3)
|
Max.
|
83
|
73
|
80
|
35
|
36
|
|
4th Max.
|
67
|
53
|
76
|
27
|
31
|
|
24-hr
|
125 (3)
|
Max.
|
17
|
17
|
20
|
15
|
14
|
|
4th Max.
|
16
|
16
|
16
|
12
|
13
|
|
No. of Exceedance(s)
|
0
|
0
|
0
|
0
|
0
|
|
Nitrogen Dioxide (NO2)
|
1-hr
|
200 (18)
|
Max.
|
176
|
178
|
198
|
185
|
183
|
|
19th Max.
|
137
|
144
|
149
|
150
|
136
|
|
No. of Exceedance(s)
|
0
|
0
|
0
|
0
|
0
|
|
Annual
|
40
|
-
|
38
|
34
|
35
|
32
|
28
|
Notes:
[1] Existing AQOs, which is put in force since
1 January 2014, are referenced to evaluate past air quality conditions. Values in ( ) mean the number of exceedances
allowed per year.
[2] Bolded values mean exceedance of the AQOs.
[3] All concentration units are in microgram
per cubic metre (µg/m3).
3.3.1.5
Apart from the air quality monitoring data, EPD
has released a set of background air quality levels extracted from “Pollutants
in the Atmosphere and their Transport over Hong Kong” (PATH) model (PATH v2.1)
in July 2021. The PATH model Year 2025
data of the assessment area are summarised in Table 3.3
below. The 19th highest
24-hour and annual average concentrations of FSP would comply with the new
AQOs, and all other pollutants level would also comply with the new AQOs.
Table 3.3 Background Air Pollutants in Year
2025 Extracted from the PATH Model (PATH v2.1)
|
Pollutant
|
Averaging Time
|
AQO [1]
|
Data Summary
|
PATH-2020 Grid in
Year 2025 [2][5]
|
|
41,42
|
41,43
|
42,41
|
42,42
|
42,43
|
43,41
|
43,42
|
|
Fine
Suspended Particulates (FSP) [3]
|
24-hr
|
50 (18)
|
Max.
|
65
|
66
|
69
|
65
|
66
|
68
|
69
|
|
19th
Max.
|
32
|
33
|
33
|
32
|
32
|
33
|
33
|
|
No.
of Exceedance(s)
|
6
|
6
|
8
|
7
|
6
|
7
|
8
|
|
Annual
|
25
|
-
|
14
|
14
|
15
|
14
|
14
|
15
|
15
|
|
Respirable
Suspended Particulates (RSP) [4]
|
24-hr
|
100 (9)
|
Max.
|
81
|
82
|
85
|
81
|
82
|
84
|
85
|
|
10th
Max.
|
62
|
63
|
62
|
64
|
63
|
63
|
64
|
|
No.
of Exceedance(s)
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
Annual
|
50
|
-
|
26
|
26
|
27
|
26
|
26
|
27
|
27
|
|
Sulphur
Dioxide (SO2)
|
10-min
|
500 (3)
|
Max.
|
57
|
52
|
48
|
59
|
60
|
47
|
49
|
|
4th
Max.
|
57
|
52
|
48
|
59
|
60
|
47
|
49
|
|
No.
of Exceedance(s)
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
24-hr
|
50 (3)
|
Max.
|
15
|
15
|
14
|
15
|
14
|
14
|
14
|
|
4th
Max.
|
10
|
10
|
10
|
10
|
10
|
10
|
10
|
|
No.
of Exceedance(s)
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
Nitrogen
Dioxide (NO2)
|
1-hr
|
200 (18)
|
Max
|
144
|
150
|
156
|
151
|
156
|
149
|
153
|
|
19th
Max.
|
69
|
63
|
96
|
76
|
65
|
94
|
91
|
|
No.
of Exceedance(s)
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
Annual
|
40
|
-
|
11
|
11
|
18
|
14
|
12
|
18
|
18
|
Notes:
|
[1] New AQOs, which come into effect on 1 January 2022, are
referenced to evaluate background air quality conditions. Values in ( ) mean the number of
exceedances allowed per year.
[2] Bolded values mean exceedance of the AQOs.
[3] Annual FSP concentration is adjusted by adding 3.5 µg/m3
with reference to Guidelines on Choice of Models and Model Parameters.
[4] 10th highest daily and
annual RSP concentration is adjusted by adding 11.0 µg/m3 and 10.3
µg/m3 respectively with reference to “Guidelines on Choice of
Models and Model Parameters”.
[5] All concentration units
are in microgram per cubic metre (µg/m3).
|
3.4.1.1
In accordance with Clause 3.4.4.2 of the EIA
Study Brief, the assessment area is defined by a distance of 500m from the
boundary of the Project area as
illustrated in Figure
3.1.
3.4.1.2
For identification of the representative ASRs
within the assessment area that would likely be affected by the potential
impacts from the Project, a review has been conducted based on relevant
available information including topographic maps, Outline Zoning Plans (OZPs)
(such as the
Draft Shatin OZP No. S/ST/35) and other published plans in the vicinity
of the Project site. The representative
ASRs are identified and summarised in Table
3.4.
Table 3.4 Representative Air Sensitive
Receivers
|
ASR
|
Description
|
Land Use
|
No. of Storeys
|
Approximate Horizontal Distance from the Nearest Site Boundary
(m)
|
|
Existing
Air Sensitive Receivers
|
|
A1
|
Kwai
Tei New Village
|
Residential
|
3
|
38
|
|
A2
|
Kwai
Tei Village
|
Residential
|
3
|
122
|
|
A3
|
Chun
Yeung Estate
|
Residential
|
34-39
|
9
|
|
A4
|
Village
House
|
Residential
|
1
|
27
|
|
A5a
|
Industrial
Buildings in Fo Tan
|
Industrial
|
14
|
10
|
|
A5b
|
Industrial
Buildings in Fo Tan
|
Industrial
|
15
|
6
|
|
A5c
|
Industrial
Buildings in Fo Tan
|
Industrial
|
18
|
35
|
|
A6
|
The
Grandville
|
Residential
|
22
|
217
|
|
A7
|
Pat
Tsz Wo Village
|
Residential
|
3
|
230
|
|
A8
|
Wo
Liu Hang
|
Residential
|
3-4
|
180
|
|
A9
|
Yuk
Wo Court
|
Residential
|
47
|
37
|
|
A10
|
Tao
Miao Institute
|
Educational
Institution
|
4
|
20
|
|
A11
|
Fo
Tan Village
|
Residential
|
1-3
|
5
|
|
A12
|
Sui
Wo Court
|
Residential
|
36
|
167
|
|
A13
|
P.L.K.
Siu Hon Sum Primary School
|
Educational
Institution
|
6
|
194
|
|
A14
|
Fo
Tan Railway House
|
Office
|
8
|
5
|
|
A15
|
The
Palazzo
|
Residential
|
40-42
|
68
|
|
A16
|
Jockey
Club TI-I College
|
Educational
Institution
|
5-6
|
46
|
|
A17
|
Hong
Kong Jockey Club Shatin Staff Quarters
|
Residential
|
20
|
75
|
|
A18
|
Hong
Kong Sports Institute
|
Educational
Institution
|
11
(the highest building)
|
20
|
|
A19
|
Hong
Kong Institute of Vocational Education (Shatin)
|
Educational
Institution
|
6
|
204
|
|
A20
|
Wo
Che Estate
|
Residential
|
13-40
|
238
|
|
A21
|
Sha
Tin Ambulance Depot/ New Territories Command Headquarters & Sha Tin Fire
Station
|
Office
|
2
|
20
|
|
A22
|
City
One Shatin
|
Residential
|
27-34
|
236
|
|
A23
|
Ravana
Garden
|
Residential
|
27-30
|
252
|
|
A24
|
Leung
Kui Kau Lutheran Primary School
|
Educational
Institution
|
6
|
373
|
|
A25
|
Fo
Tan Cooked Food Market (East)
|
Commercial
|
1
|
0
|
|
A26
|
Fo
Tan Cooked Food Market (West)
|
Commercial
|
1
|
0
|
|
A27
|
Shan
Mei Street Basketball Court
|
Recreational
|
-
|
3
|
|
A28
|
Shan
Mei Street Playground
|
Recreational
|
-
|
5
|
|
Planned
Air Sensitive Receivers
|
|
AP1
|
Planned
Primary School at No. 1-11 Au Pui Wan Street, Fo Tan
|
Educational
Institution
|
-
|
70
|
|
AP2
|
Planned
Residential Developments at No. 1-11 Au Pui Wan Street, Fo Tan
|
Residential
|
39-41
|
18
|
3.5.1.1
The construction of the Project would commence
in January 2024 and complete by November 2029.
Referring to the tentative construction programme in Appendix 2.2, the Project Site
would be divided into six work sections for construction, Section 1 to Section
6. The locations of the six work
sections are indicated in Figure
3.1. The main
construction tasks of the Project include:
(a) Desilting
at downstream tidal zone for Work Section 1
(b) Channel
bed modification for Work Section 1 to 5
(c) Improvement
of existing walkways such as construction of viewing deck/pavilion, renovation
of existing footbridges for Work Section 1 to 6
(d) Construction
of dry weather flow interceptor (DWFI) system along the nullah and associated
connection works to existing sewerage system for Work Section 2 to 6
(e) Landscape
works along nullah bank and utility works for Work Section 1 to 6
(f) Construction
of underground water storage tank for Work Section 6
(g) Construction
of submersible water pumps and underground water pipes (mainly housed within
the DWFI system) for ecological enhancement associated water retention and
supplement for Work Section 3 to 6 (to be constructed alongside construction of
DWFI system)
3.5.1.3
Construction dust is the major concern during
construction of the Project. Fugitive
dust generated from various construction activities, including excavation,
backfilling, and wind erosion of the excavated areas and stockpiles, would be
major dusty activities which would impose potential dust impact on the air
sensitive receivers in the vicinity.
3.5.1.4
The operation of powered mechanical equipment
(PMEs) within the construction area and the construction vehicles for the
transportation of materials would contribute to the gaseous emissions to the
surrounding air.
3.5.1.5
Potential odour emission may be generated during
the desilting works at downstream tidal zone/excavation of nullah bed and the
transfer and disposal of desilted/excavated materials.
3.5.2.1
The purpose of the Project is to revitalise the
existing concrete-lined FTN into a green open space to connect the community
with nature. The beautification and
vegetating of the existing nullah would bring positive influence on the surrounding
environment. In view of the Project
nature, adverse air quality impact due to the operation of the Project is not
anticipated. With the implementation of
DWFI system under the Project, the polluted discharges from drainage outlets
along the nullah would be intercepted and diverted to the existing sewerage system for conveying to
Shatin Sewage Treatment Works for treatment.
It is expected that the odour nuisance of FTN would be alleviated
due to the operation of the Project.
3.6
Prediction and Evaluation of Environmental Impacts
3.6.1
Construction Phase
Fugitive Dust
3.6.1.1
The Project will be constructed in sections by
sections. The construction works at the
nullah will be divided into six sections and the construction activities will
not be undertaken at the entire work site at the same time. The construction tasks for each work section
would be completed before commencement of the similar construction tasks at
another work section. As mentioned in Section 3.5.1.2, the maximum size of the active
construction work area at any one time would not be longer than 100m along the
nullah at each work area. Hence, the
active exposed work site would be limited.
3.6.1.2
Various construction activities, including
excavation, backfilling, material handling and wind erosion of the excavated
areas and stockpiles would be the main sources of fugitive dust. The production of concrete would be conducted
with the use of a concrete lorry mixer, therefore, adverse dust impact is not
anticipated.
3.6.1.3
Referring to construction programme in Appendix
2.2, the excavation works for the nullah bed
per work section and underground water storage tank under existing Kwei Tei Street Garden would be 1
month and not more than 4 months, respectively.
3.6.1.4
The excavated materials would be well covered
with impervious sheeting and then use for backfilling/re-surfacing along the
nullah in the next three months.
According to the engineering design, the total volume of construction
and demolition (C&D) materials to be excavated for the whole construction
period is estimated to be about 44,400m3, with the majority of about
36,600m3 inert C&D materials to be reused on-site for
backfilling, about 4,800m3 inert C&D materials to be delivered
to public fill reception facility (PFRF) for beneficial reuse, and about 3,000m3
non-inert C&D materials to be disposed at strategic landfill. The C&D materials for backfilling or
off-site disposal would be temporarily stored on-site and would be well covered
with impervious sheeting. As the
excavation works and backfilling along the nullah will be conducted section by
sections, the volume of inert C&D materials temporary stored on-site is
expected to be not more than 1,000m3 at any time.
3.6.1.5
Due to the small amount of C&D materials to
be disposed off-site, the dust generated from construction vehicles for
materials handling would generally be limited within the work areas. In accordance with the preliminary
engineering information, for the inert C&D materials, it is proposed to
dispose at Tseung Kwan O Area 137 Fill Bank for beneficial reuse in other
projects via Lung Cheung Road and Kwun Tong Road or other approved PFRF. It is estimated that an average of about 1
truck trip per day would be required to dispose these materials off-site. For non-inert C&D materials, it is
planned to deliver to SENT landfill via Lung Cheung Road and Kwun Tong Road or
other approved landfills. It is
estimated that an average of about 1 truck trip per day would be required. Considering the limited number of dump trunk
in operation together with tarpaulin covering of these dump trucks and washing
the vehicle wheel and body before leaving the construction site, dust nuisance
during transportation of the C&D materials would not be anticipated.
3.6.1.6
For the proposed underground water storage tank
in Work Section 6, it is within Kwei
Tei Street Garden with works area of approximately
300m2 (10m x 30m). In order
to match the downstream invert level of the nullah, it will
be installed at shallow depth with excavation depth of approximately 2.5 m. The
foundation and excavation works for the proposed storage tank would be last for
9 months only. The excavated materials
for the tank would be about 750m3 while the total excavated
materials from foundation works and construction of associated pipeworks would
be about 55m3. The
representative ASRs nearest to the proposed storage tank are ASR A3 and A5a and
the separation distances are about 34m and 37m, respectively. As confirmed by the Engineers, the construction of the storage tank and
other construction works in Work Section 6 would not be overlapped to avoid cumulative air quality impact on nearby ASRs. Considering the limited works area, small
amount of excavated materials from excavation works and the avoidance of
cumulative impact from other construction works in Work Section 6 together with
the implementation of typical dust suppression measures as mentioned in Section 3.7.1 to minimise dust generation, adverse
dust impact from the construction of the proposed tank would not be
anticipated.
3.6.1.7
Given that the construction works of the Project
would be of small-scale and confined in a smaller work area, small influence
zone would be expected. With proper and
effective implementation of good site practices and mitigation measures
stipulated in the Air Pollution Control (Construction Dust) Regulation, dust
emission from the construction works would be well controlled and
minimised. No adverse construction dust
impacts from the Project would therefore be anticipated.
Operation of PMEs
3.6.1.8
The fuel combustion from the use of PMEs during
construction works could be a potential source of air pollutants such as PM, NO2,
SO2 and CO. To improve air quality,
Air Pollution Control (Fuel Restriction) Regulation and Air Pollution control
(Non-road Mobile Machinery) (Emission) Regulation are introduced to regulate SO2
emissions from commercial and industrial processes, and emissions from
machines and non-road vehicles respectively.
In addition, all construction plants are required to use
ultra-low-sulphur diesel (ULSD) (defined as diesel fuel containing not more
than 0.005% sulphur by weight) as stipulated in Environment, Transport and
Works Bureau Technical Circular (ETWB-TC(W)) No. 19/2005 on Environmental
Management on Construction Sites.
3.6.1.9
The number and type of PMEs to be used on site
for each main construction task under Work Sections 1 to 6 are presented in Appendix
4.6.
According to the preliminary engineering design, while there would be
several sub-group construction works under each main construction task, the
construction periods of these sub-group works would not be overlapped. Therefore, the PMEs of each sub-group
works/construction sequence would not be operated concurrently. Based on the construction programme presented
in Appendix 2.2 and the plant inventory attached in Appendix
4.6, there would be up to 4 concurrent
construction tasks, namely “Construction of Viewing Deck / Pavillion,
Renovation of Existing Footbridges” (Group 1B-1), “Landscaping / Greening along Nullah Bank”
(Group 1D-1) and “Utility Works” (Group 1D-2) and “Connection Work to the
Existing Sewerage System” (Group 2C-1) within 500m assessment area and a total
of 13 nos. NRMM in operation. These 4
tasks would be carried out concurrently in July 2024 (limited for one
month). As the
works are divided into small sections, the potential air quality impacts would
be limited. With proper and
effective implementation of the good practices as stated in the regulations, no
significant dust and gaseous emission impacts from the use of PME would be
anticipated.
Odour
3.6.1.10
Desilting works at downstream tidal zone would
tentatively be undertaken at the commencement and prior
to the completion of the construction works respectively to remove the
accumulated silting and debris at the nullah.
Each desilting works would take about two
months to complete and about 2,000m3 of desilted materials would be
produced. Potential odour
nuisance would be expected during desilting works. However, the desilted materials will be
contained in watertight container on-site immediately and be transported
off-site by trucks for disposal of at strategic landfill within one day. Therefore, the odour emissions are likely to
be minimal and localised at a short duration.
3.6.1.12 The
desilted materials and excavated materials from the nullah bed would be
enclosed during trucking, therefore, very minor odour nuisance would be
expected during transportation of these materials for disposal.
Cumulative impacts from concurrent projects
3.6.1.13
As presented in Section 2.8, there are
four concurrent projects which would potentially overlap with the construction
of the Project is identified within the 500m assessment area, including (i) Drainage Improvement Works in Sha Tin and Sai Kung, (ii) Relocation of
Sha Tin Sewage Treatment Works to caverns – Upstream Sewerage and Pumping
Stations, (iii) Redevelopment of Housing Authority’s (HA) Sui Fai
Factory Estate into for Residential Use, and (iv) New Facilities Building of
the Hong Kong Sports Institute (HKSI).
Based on the construction programme of the Project, the cumulative
impacts from these concurrent projects have been considered.
3.6.1.14
The cumulative impacts associated with the
project - “Drainage Improvement Works in Sha Tin and Sai Kung”, which is
scheduled to construct in 2023-2031, is expected to be minor due to the long
separation between the works boundaries of this current project and the Project
(more than 280m). In addition, consider
that both projects would implement good site practices and dust suppression
measures, no adverse cumulative dust impact would be anticipated.
3.6.1.15
For “Relocation of Sha Tin Sewage Treatment
Works to caverns – Upstream Sewerage and Pumping Stations”, it is to construct
a new 1,200m diameter pipe along Shing Mun River. The construction period of this project is
from end 2020 to 2024, which would be overlapped with the Project for less than
one year. Since this project would be at
its final stage of construction during the overlapping period, extensive
excavation works would not be anticipated.
In addition, both projects would implement good site practices and dust
suppression measures, no adverse cumulative dust impact would be anticipated.
3.6.1.16
For the “Redevelopment of HA’s (HA) Sui Fai
Factory Estate for Residential Use”, it is to demolish the existing Sui Fai
Factory Estate and redevelop the site for residential use which is tentatively
planned to be occupied in 2031 but no detailed construction programme of the
redevelopment project is available at time of the preparation of this EIA
Report that potential cumulative environmental impacts associated with this
planned development have not been taken into account. Nonetheless, consider the small and confined
scale of the works area of the construction works of this Project, the
construction dust impact is expected to be limited and well controlled with
proper and effective implementation of good site practices and mitigation
measures stipulated in the Air Pollution Control (Construction Dust)
Regulation. During the detailed design
stage, the contractor of this Project should be requested to closely liaise the
contractors of this potential concurrent HA project in planning the interfacing
works properly to minimise the potential cumulative impacts by
avoiding/minimising repeated and concurrent heavy construction works.
3.6.1.17
For “New Facilities Building of the HKSI”, it is
to construct a new building within the HKSI facing the FTN and Shing Mun
River. The planned building is targeted
for completion in mid-2024, which would be overlapped with the Project for less
than one year. Since the main works of
this building development project would be at its final stage of construction
during the overlapping period, excavation works would not be anticipated. In addition, consider that both projects
would implement good site practices and dust suppression measures, no adverse
cumulative dust impact would be anticipated.
3.6.2
Operational Phase
3.6.2.1
As mentioned in Section
3.5.2.2, similar to the existing practices by the
DSD, regular maintenance works for the drainage and sewerage systems along FTN,
including maintenance desilting at the nullah and minor maintenance to the DWFI
system, to remove excessive silts, debris and obstruction to safeguard the
hydraulic capacity of the nullah would be required. Maintenance
desilting of the nullah should be carried out on an annual basis during
dry season (November to March) when the water flow is low, except during emergency situations
where the accumulated silt would adversely affect the hydraulic capacity of the
nullah or where flooding risk is imminent, or when complaints on environmental
nuisance associated with the accumulated silt are received. Moderate siltation would generally be allowed
to accumulate, and removal of excess silt would be carried out at locations
where it would impede water flow.
Maintenance works would also be undertaken for the DWFI system on an
as-needed basis and frequent maintenance (i.e. monthly) would not be
required. The maintenance practices and
frequency would be similar to the existing maintenance works undertaken by the
DSD. Such small-scale maintenance would
require only light mechanical equipment such as a small loader and/or a small
crane truck. Hand-held equipment would
be used for vegetation removal.
Therefore, adverse impacts from dust and gaseous emission are not
expected.
3.6.2.2
While the odour nuisance of FTN is anticipated
to be alleviated with the implementation of DWFI system under the Project to
intercept the polluted discharges from drainage outlets along the nullah,
desilted materials from the maintenance/desilting works may be found to be
odorous when exposed to air. While minor
odour impact may arise from maintenance/desilting works, the desilted materials
will be properly covered with tarpaulin / contained in watertight container
on-site immediately and be located as far away from the ASRs as possible and be
transported off-site by trucks for disposal of at strategic landfill within one
day. As such, any odour impact during
the maintenance would be temporary and confined to the areas of maintenance
works that it would be well-controlled through good site practices described in
Section
3.7. No
adverse odour impact would be anticipated.
3.7.1.1
Sufficient dust suppression measures as
stipulated under the Air Pollution Control (Construction Dust) Regulation (Cap.
311R) and good site practices such as enclosing stockpiles of sand with
three-side enclosure, covering the dusty materials with clean impervious sheet,
water spraying of all access roads and site areas, and good house-keeping of
the site should be properly implemented in order to minimise the construction
dust generation. These measures include
the followings:
a)
Use of
regular watering, to reduce dust emissions from exposed site surfaces and
unpaved roads particularly during dry weather;
b)
Use of
frequent watering in particularly dusty construction areas close to ASRs;
c)
Use of
frequent watering or water sprinklers for major haul roads, material
stockpiling areas and other dusty activities within the construction site;
d)
Side
enclosure and covering of any aggregate or dusty material storage piles to
reduce emissions. Where this is not
practicable owing to frequent usage, watering should be applied to aggregate
fines;
e)
For the
work sites close to the ASR with a separation distance less than 5m, provide
hoardings of not less than 5m high from ground level along the site boundary;
for the work sites close to the ASRs with a separation distance between 5m and
10 m, provide hoardings of not less than 3.5 m high from ground level along the
site boundary; for other work sites, provide hoardings of not less than 2.4 m
high from ground level along the site boundary except for site entrance or
exit;
f)
Open
temporary stockpiles should be avoided or covered. Prevent placing dusty material storage plies
near ASRs;
g)
Tarpaulin
covering of all dusty vehicle loads transported to, from and between site
locations;
h)
Establishment
and use of vehicle wheel and body washing facilities at the exit point of the
site;
i)
Imposition
of speed control for vehicles on unpaved site roads. 8 km/hr is the recommended limit;
j)
Routing
of vehicles and positioning of construction plants should be at the maximum
possible distance from ASRs;
k)
Avoid
position of material stockpiling areas, major haul roads and dusty works within
the construction site close to concerned ASRs;
l)
Avoid
unnecessary exposed earth; and
m)
During or after the de-bagging process, the use
of cement or dry pulverised fuel ash should be conducted in a totally enclosed
system or facility and effective air pollution control measures should be
placed at any exits or exhaust to avoid potential air quality influence.
3.7.1.2
Guidelines stipulated in EPD’s Recommended
Pollution Control Clauses for Construction Contracts should be incorporated in
the contract documents to abate dust impacts.
The clauses include:
·
The Contractor shall observe and comply with the
APCO and its subsidiary regulations, particularly the Air Pollution Control
(Construction Dust) Regulation.
·
The Contractor shall undertake at all times to
prevent dust nuisance as a result of the construction activities.
·
The Contractor shall ensure that there will be
adequate water supply / storage for dust suppression.
·
The Contractor shall devise and arrange methods
of working and carrying out the works in such a manner so as to minimise dust
impacts on the surrounding environment, and shall provide experienced personnel
with suitable training to ensure that these methods are implemented.
·
Before the commencement of any work, the
Contractor may be required to submit the methods of working, plant, equipment
and air pollution control system to be used on the site for the Engineer
inspection and approval.
3.7.1.3
In order to minimise the exhaust emissions from
NRMMs during construction phase, the requirements as stipulated in the Air
Pollution Control (Non-road Mobile Machinery) (Emission) Regulation shall be
followed. The following measures are
also recommended to be implemented:
·
Connect construction plant and equipment to
mains electricity supply and avoid use of diesel generators and diesel-powered
equipment;
·
Deploy electrified NRMMs as far as practicable;
and
·
Use of exempted NRMMs not allowed.
3.7.2
Operational Phase
3.8
Evaluation of Residual Impacts
3.8.1
Construction Phase
3.8.1.1
With proper and effective implementation of the
good site practices and mitigation measures as stipulated in relevant
Regulations and proposed in Section 3.7, no adverse residual air quality
impact would be expected.
3.8.2
Operational Phase
3.9
Environmental Monitoring and Audit
3.9.1.1
No adverse air quality impact due to the
construction of the Project would therefore be anticipated. Nonetheless, dust monitoring is recommended
during the construction of the underground water storage tank at Kwei Tei Street Playground to
ascertain that there would be no adverse dust impacts at the nearby sensitive
receivers. Regular weekly site
environmental audit is also recommended to ensure the implementation of recommended
mitigation measures during construction phase.
Details of the monitoring and audit programme are contained in a
stand-alone EM&A Manual. No EM&A
programme is required during operational phase.
3.10.1.1
The potential air quality impacts arising from
the construction of the Project would be related to fugitive dust emissions
from construction works and gaseous emissions from the use of PME, and odour
nuisance from desilted / excavated materials
generated during the desilting at downstream tidal
zone / excavation works in the nullah. In view of the small scale of the
Project, the air quality impacts would be localised and minor, and would be
well controlled through the implementation of good site practices and dust
suppression measures stipulated in the Air Pollution Control (Construction
Dust) Regulation as well as the proposed good site practices to minimise
the exhaust emissions from NRMMs and odour
nuisance from handling of desilting/excavated materials. Dust monitoring for construction of the
underground water storage tank at Kwei Tei Street Garden and regular weekly site audit are
recommended to be carried out during construction phase in order to confirm
that the mitigation measures are properly implemented and are working
effectively. No
adverse air quality impact due to the construction of the Project would
therefore be anticipated.
3.10.1.2
No adverse air quality impact due to the
operation of the Project would be anticipated.
With the implementation of DWFI system under the Project to intercept
and divert the polluted discharges from drainage outlets along the nullah to
the existing sewerage system for treatment, the odour nuisance of FTN would be
alleviated as a result of the operation of the Project. Any odour emission generated from exposed
desilted materials during the routine maintenance works would be temporary and
confined to the areas of maintenance works that it would be well-controlled
through good site practices. No adverse air
quality impact due to the operation of the Project would be anticipated.