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4 AIR QUALITY
4.1 INTRODUCTION
This Section presents the assessment of potential air quality impacts arising
from the construction and operation of the proposed Project at Black Point
Power Station (BPPS). The Assessment Area is defined by a distance of 15
km from the boundary of the proposed Project Site. Representative Air
Sensitive Receivers (ASRs) and major emission sources associated with the
Project and other concurrent projects have been identified. Potential air
quality impacts have been evaluated and mitigation measures have been
recommended to mitigate potential adverse impacts, where appropriate.
4.2 LEGISLATIVE REQUIREMENTS AND EVALUATION CRITERIA
The principal legislation for the management of air quality in Hong Kong is
the Air Pollution Control Ordinance (APCO) (Cap. 311). Assessment criteria for
the air quality impact assessment (AQIA) will follow the prevailing Air
Quality Objectives (AQOs) which stipulate the statutory limits of typical air
pollutants in the ambient air and the maximum allowable number of
exceedances over the specified periods under APCO. The prevailing AQOs
are presented in Table 4.1 and they were used as the evaluation criteria in this
assessment.
Table 4.1 Hong Kong Air Quality Objectives
Air Pollutant Averaging Time Concentration
(g m-3) (a)
No. of Exceedances
allowed per Year
Nitrogen Dioxide (NO2) 1-hour 200 18
Annual 40 -
Sulphur Dioxide (SO2) 10 minute 500 3
24-hours 125 3
Respirable Suspended Particulates
(PM10) (b)
24-hours 100 9
Annual 50 -
Fine Suspended Particulates
(PM2.5) (c)
24-hours 75 9
Annual 35 -
Carbon Monoxide (CO) 1-hour 30,000 0
8-hour 10,000 0
Ozone (O3) 8-hour 160 9
Lead Annual 0.5 -
Notes:
(a) Measured at 293K and 101.325 kPa.
(b) Suspended particles in air with a nominal aerodynamic diameter of 10 μm or less
(c) Suspended particles in air with a nominal aerodynamic diameter of 2.5 μm or less
In addition to the APCO, a maximum hourly average Total Suspended
Particulates (TSP) concentration of 500 µg m-3 at ASRs is stipulated in Annex 4
of the Technical Memorandum on Environmental Impact Assessment Process
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(EIAO-TM) to address potential construction dust impacts. The measures
stipulated in the Air Pollution Control (Construction Dust) Regulation will be
followed to ensure that potential dust impacts are reduced. Requirements
stipulated in the Air Pollution Control (Non-road Mobile Machinery) (Emission)
Regulation will also be followed to control potential emissions from non-road
mobile machinery during construction phase. For non-AQO pollutant,
ammonia (NH3) as by-product from the Selective Catalytic Reduction (SCR)
process may be emitted from the flue gas of the CCGT units. The potential
health impact of NH3 has been addressed in Health Impact Assessment (HIA)
in Chapter 14.
4.3 ASSESSMENT AREA AND IDENTIFICATION OF ASRS
The Assessment Area is defined as an area within 15 km from the Project Site
boundary as stated in Section 3.4.3.2 of the EIA Study Brief. The Assessment
Area includes:
Ha Pak Nai; Tuen Mun South;
Sheung Pak Nai; Hung Shui Kiu;
Lung Kwu Tan; Siu Lam;
Lung Kwu Sheung Tan; Tai Lam;
Lau Fau Shan; So Kwun Wat;
Tin Shui Wai; Tung Chung; and
Yuen Long; Siu Ho Wan
Tuen Mun North;
Representative existing, planned and committed ASRs within the Assessment
Area have been identified with reference to current land uses, relevant Outline
Zoning Plans, Development Permission Area Plans, and Outline Development
Plans and Layout Plans.
The ASRs are grouped into different geographic areas as identified above and
are presented in Table 4.2 and shown in Figure 4.1. Detailed information of all
ASRs is also provided in Annex 4A.
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Table 4.2 Identified Representative ASRs
Area ASR Description Use Approximate
Distance from
Site Boundary
(km)
Approximate
Maximum
Height (m
above ground)
Lung Kwu
Tan and
Lung Kwu
Sheung Tan
LKT1 Sludge Treatment
Facilities (STF) Office
GIC 2.0 60
LKT2 WENT Extension Site
Office
GIC 2.0 1.5
LKT3 Lung Kwu Sheng Tan Residential 1.2 10
LKT4 Planned Development
at Lung Kwu Tan
Residential 1.0 120
LKT5 Long Kwu Tan Residential 2.9 10
Ha Pak Nai,
Sheung Pak
Nai and Lau
Fau Shan
LFS1 West Ha Pak Nai Residential 3.4 10
LFS2 Sheung Pak Nai Residential 6.6 10
LFS3 Lau Fau Shan Market Commercial 9.8 10
LFS4 Mong Tseng Village Residential 11.8 10
Tin Shui Wai TSW1 Kwok Yat Wai College Educational
Institution
10.6 20
TSW2 Kenswood Court -
Kingswood Villas
Residential 11.1 120
TSW3 Pak Kau College Educational
Institution
11.4 40
TSW4 Tin Shui Estate Residential 10.2 120
TSW4a Tin Yan Estate Residential 10.4 120
TSW4b Tin Wah Estate Residential 10.3 80
TSW4c Tin Chung Court Residential 10.7 120
TSW5 Kingswood Villas Residential 10.3 120
TSW6 Yan Wu Garden Residential 9.5 10
TSW7 Low-rise building on
Man Tak Road
Residential 10.0 20
Yuen Long YL1 Tai Tong Tuen Residential 11.7 10
YL2 Nam Hang Tsuen Residential 13.1 10
YL3 Shan Ha Tsuen Residential 11.3 10
YL4 Shap Pat Heung Residential 13.0 10
YL5 Shui Pin Tsuen Recreational 12.0 10
YL5a Shui Pin Wai Estate Residential 11.9 80
YL5b Man Cheong Building Commercial 12.4 20
YL6 Park Royale Residential 11.5 40
YL7 Hang Tau Tsuen Residential 10.9 10
YL8 Long Ping Estate Wah
Ping House
Residential 12.3 120
YL9 Yoho Midtown Residential 13.5 120
YL10 Yee Fung Garden Residential 12.3 100
Tuen Mun
North, Hung
Shui Kiu
HSK1 Ho Dao College Educational
Institution
9.5 20
HSK2 Belrose Place Residential 8.0 20
HSK3 Fu Tai Tsing Tsuen Residential 7.7 120
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Area ASR Description Use Approximate
Distance from
Site Boundary
(km)
Approximate
Maximum
Height (m
above ground)
HSK4 Tuen Mun Hospital Healthcare
Institution
6.8 40
HSK5 Leung King Estate Residential 5.4 120
Tuen Mun
South
TM1 Tai Hing Garden Residential 6.5 120
TM1a Lakeshore Building Residential 7.1 60
TM1b Parkview Court Residential 6.9 100
TM2 Kam Hing Building Residential 6.8 100
TM3 Tuen Mun Town Plaza Residential 7.1 120
TM4 On Ting Estate Residential 7.3 120
TM4a Yau Oi Estate Residential 7.0 80
TM5 Lung Mun Oasis Residential 6.5 120
TM6 Yuen Wu Villa Residential 7.2 100
TM7 Butterfly Estate Residential 6.8 100
TM7a Melody Garden Residential 6.5 100
TM7b Siu Shan Court Residential 6.5 60
TM8 River Trade Terminal GIC 5.5 10
TM9 Kingston Terrace Residential 7.3 120
TM10 Chi Lok Fa Yuen Residential 7.6 60
So Kwun
Wat, Siu
Lam, Tai
Lam
SKW1 Maritime Services
Training Institute
Educational
Institution
12.4 10
SKW2 Siu Lam Hospital Healthcare
Institution
12.0 40
SKW3 Palatial Coast - Grand
Pacific View
Residential 11.6 100
SKW4 Siu Sau Tsuen Place of
Public
Worship
10.5 10
SKW5 Ka Wo Lei Residential 10.1 10
SKW6 Gold Coast Phase 2 Residential 10. 0 100
SKW7 Gold Coast Hotel Residential 9.2 60
SKW8 Harrow International
School
Educational
Institution
9.1 20
SKW9 Seaview Garden Residential 8.5 100
Tung Chung
Siu Ho Wan
TC1 North Lantau Hospital Healthcare
Institution
14.5 40
TC2 Coastal Skyline Phase
3
Residential 13.6 120
TC2a Seaview Crescent Residential 13.5 120
TC2b Coastal Skyline La
Rossa
Residential 13.7 120
TC2c Yu Tung Court Residential 13.9 100
TC2d Tung Chung Crescent Residential 13.8 120
TC3 The Visionary Residential 13.4 120
TC4 Planned Residential
Developments at Tung
Chung East
Residential 13.2 120
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Area ASR Description Use Approximate
Distance from
Site Boundary
(km)
Approximate
Maximum
Height (m
above ground)
TC5 Ling Liang Church E
Wun Secondary School
Educational
Institution
13.8 40
TC6 Ching Chung Hau Po
Woon Primary School
Educational
Institution
13.9 40
Siu Ho Wan SHW1 Pak Mong Village Residential 14.2 10
SHW2 Siu Ho Wan Depot GIC 13.6 20
SHW3 Proposed Lantau
Logistic Park
GIC 13.2 40
SHW4 Luk Keng Tsuen Residential 14.6 10
4.4 BASELINE CONDITION
The proposed Project is located within the existing boundaries of the BPPS.
The area has a very low population density and the local air quality is
primarily influenced by industrial emissions from the existing BPPS, Castle
Peak Power Station (CPPS) and other industrial facilities.
4.4.1 Measured Background Air Quality from Air Quality Monitoring Stations
Three EPD air quality monitoring stations (AQMS) in Yuen Long, Tung
Chung and Tuen Mun, and five AQMSs operated by CLP in Butterfly Estate,
Tuen Mun Clinic (or San Hui), Tin Shui Wai, Lung Kwu Tan and Lau Fan
Shan are located within the Assessment Area. Table 4.3 to Table 4.10 provide
the relevant time averaging concentrations of air pollutants measured at these
AQMSs in the most recent 5 years for comparison with the prevailing AQOs.
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Table 4.3 Concentrations of Air Pollutants Measured at EPD’s Yuen Long AQMS in the
Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th
highest
1-hr
NO2
Ann-
ual
NO2
4th
highest
24-hr
SO2
4th
highest
10-min
SO2 (a)
10th
highest
24-hr
RSP
Ann-
ual
RSP
10th
highest
24-hr
FSP
Ann-
ual
FSP
10th
highest
8-hr O3
Max.
1-hr
CO
Max.
8-hr
CO
2010 194 54 (b) 36 - 115 (c) 49 73 32 123 2,730 2,148
2011 188 54 (b) 33 - 111 (c) 54 (d) 76 (e) 36 (f) 138 3,210 2,360
2012 147 49 (b) 29 - 100 (c) 44 65 29 163 (g) 2,200 1,829
2013 183 54 (b) 33 - 142 (c) 56 (d) 106 (e) 37 (f) 130 2,690 1,911
2014 165 52 (b) 27 92 124 (c) 50 86(d) 35 159 2,560 2,107
Prevail-
ing
AQOs
200 40 125 500 100 50 75 35 160 30,000 10,000
Notes:
(a) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min SO2 AQO was
in place in 2014).
(b) Exceedance of annual average NO2 criterion.
(c) Exceedance of 24-hour average RSP criterion.
(d) Exceedance of annual average RSP criterion.
(e) Exceedance of 24-hour average FSP criterion.
(f) Exceedance of annual average FSP criterion.
(g) Exceedance of 8-hour average O3 criterion.
Table 4.4 Concentrations of Air Pollutants Measured at EPD’s Tung Chung AQMS in
the Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th
highest
1-hr
NO2
Ann-
ual
NO2
4th
highest
24-hr
SO2
4th
highest
10-min
SO2 (a)
10th
highest
24-hr
RSP
Ann-
ual
RSP
10th
highest
24-hr
FSP
Ann-
ual
FSP
10th
highest
8-hr O3
Max.
1-hr
CO
Max.
8-hr
CO
2010 203 (b) 44 (c) 46 - 111 (d) 45 79 (e) 29 143 2,910 2,398
2011 184 51 (c) 38 - 111 (d) 47 79 (e) 32 151 2,290 2,108
2012 166 43 (c) 33 - 106 (d) 45 74 28 161 (f) 2,660 2,248
2013 177 49 (c) 39 - 108 (d) 42 76 (e) 26 147 1,810 1,580
2014 198 45 (c) 35 86 101 (d) 39 65 24 159 2,230 1,560
Prevail-
ing
AQOs
200 40 125 500 100 50 75 35 160 30,000 10,000
Notes:
(a) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min SO2 AQO was
in place in 2014).
(b) Exceedance of 1-hour average NO2 criterion.
(c) Exceedance of annual average NO2 criterion.
(d) Exceedance of 24-hour average RSP criterion.
(e) Exceedance of 24-hour average FSP criterion.
(f) Exceedance of 8-hour average O3 criterion.
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Table 4.5 Concentrations of Air Pollutants Measured at EPD’s Tuen Mun AQMS in the
Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th
highest
1-hr
NO2
Ann-
ual
NO2
4th
highest
24-hr
SO2
4th
highest
10-min
SO2 (b)
10th
highest
24-hr
RSP
Ann-
ual
RSP
10th
highest
24-hr
FSP
Ann-
ual
FSP
10th
highest
8-hr O3
Max.
1-hr
CO
Max.
8-hr
CO
2010 -- -- -- -- -- -- -- -- -- -- --
2011 -- -- -- -- -- -- -- -- -- -- --
2012 -- -- -- -- -- -- -- -- -- -- --
2013 -- -- -- -- -- -- -- -- -- -- --
2014 184 53 (c) 33 128 125 (d) 47 83 (e) 30 146 2,610 1,743
Prevail-
ing
AQOs
200 40 125 500 100 50 75 35 160 30,000 10,000
Notes:
(a) Tuen Mun AQMS in operation since 2014.
(b) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min SO2 AQO was
in place in 2014).
(c) Exceedance of 1-hour average NO2 criterion.
(d) Exceedance of 24-hour average RSP criterion.
(e) Exceedance of 24-hour average FSP criterion.
Table 4.6 Concentrations of Air Pollutants Measured at CLP’s Butterfly Estate AQMS
in the Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th highest
1-hour NO2
Annual NO2 4th highest
24-hour SO2
4th highest
10-min SO2 (c)
2010 152 38 33 -
2011 175 41 (b) 25 -
2012 147 45 (b) 26 -
2013 204 (a) 47 (b) 31 -
2014 169 42 (b) 28 121
Prevailing
AQOs
200 40 125 500
Notes:
(a) Exceedance of 1-hour average NO2 criterion.
(b) Exceedance of annual average NO2 criterion.
(c) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min
SO2 AQO was in place in 2014).
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Table 4.7 Concentrations of Air Pollutants Measured at CLP’s Lau Fau Shan AQMS in
the Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th highest
1-hour NO2
Annual NO2 4th highest
24-hour SO2
4th highest
10-min SO2 (a)
2010 164 29 25 -
2011 171 36 33 -
2012 136 30 27 -
2013 155 30 23 -
2014 147 31 22 164
Prevailing
AQOs
200 40 125 500
Note:
(a) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min
SO2 AQO was in place in 2014).
Table 4.8 Concentrations of Air Pollutants Measured at CLP’s Lung Kwu Tan AQMS in
the Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th highest
1-hour NO2
Annual NO2 4th highest
24-hour SO2
4th highest
10-min SO2 (a)
2010 149 26 60 -
2011 153 31 38 -
2012 128 26 31 -
2013 149 28 34 -
2014 149 27 24 131
Prevailing
AQOs
200 40 125 500
Note:
(a) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min SO2
AQO was in place in 2014).
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Table 4.9 Concentrations of Air Pollutants Measured at CLP’s Tin Shui Wai AQMS in
the Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th highest
1-hour NO2
Annual NO2 4th highest
24-hour SO2
4th highest
10-min SO2 (b)
2010 172 40 33 -
2011 150 39 24 -
2012 125 32 29 -
2013 180 45(a) 32 -
2014 154 34 34 149
Prevailing
AQOs
200 40 125 500
Notes:
(a) Exceedance of annual average NO2 criterion.
(b) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min
SO2 AQO was in place in 2014).
Table 4.10 Concentrations of Air Pollutants Measured at CLP’s San Hui/Tuen Mun
Clinic AQMS in the Recent 5 Years (2010 - 2014)
Year Concentration of Pollutants (µg m-3)
19th highest
1-hour NO2
Annual NO2 4th highest
24-hour SO2
4th highest
10-min SO2 (c)
2010 206 (a) 68 (b) 52 -
2011 229 (a) 72 (b) 41 -
2012 192 65 (b) 43 -
2013 228 (a) 63 (b) 26 -
2014 195 55 (b) 23 90
Prevailing
AQOs
200 40 125 500
Notes:
(a) Exceedance of 1-hour average NO2 criterion.
(b) Exceedance of annual average NO2 criterion.
(c) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min
SO2 AQO was in place in 2014).
NO2
Exceedances of 1-hour average NO2 criterion were measured at EPD’s AQMS
in Tung Chung in 2010, CLP’s AQMSs in Butterfly Estate in 2013 and San
Hui/Tuen Mun Clinic in 2010, 2011 and 2013.
The annual average NO2 concentrations have exceeded the relevant AQO
criterion at EPD’s AQMSs in Tung Chung and Yuen Long for the past 5 years,
as well as in Tuen Mun in 2014. Exceedances of the annual average NO2
concentrations were also recorded at CLP’s AQMSs in Butterfly Estate (2011 to
2014), Tin Shui Wai (2013) and San Hui/Tuen Mun Clinic (2010 to 2014).
SO2
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No exceedance of 10-minute and 24-hour average SO2 criteria was measured
at any AQMSs operated by either EPD or CLP.
RSP (PM10)
Exceedances of 24-hour average RSP (PM10) criterion were measured at EPD’s
AQMSs in Tung Chung and Yuen Long for the past 5 years, as well as in Tuen
Mun in 2014. No exceedance of the annual average RSP (PM10) criterion was
recorded at EPD’s AQMSs except in Yuen Long in 2011 and 2013.
FSP (PM2.5)
Exceedances of 24-hour average FSP (PM2.5) criterion were measured at EPD’s
AQMSs in Tung Chung (2010, 2011 and 2013), Yuen Long (2011, 2013 and
2014) and Tuen Mun (2014). No exceedance of the annual average FSP
(PM2.5) criterion was recorded at EPD’s AQMSs except in Yuen Long in 2011
and 2013.
O3
The measured 8-hour average O3 concentrations at EPD’s AQMSs in Yuen
Long and Tung Chung in 2012 have exceeded the relevant AQO criterion.
CO
The measured 1-hour and 8-hour average CO concentrations at all EPD’s
AQMSs are well within the respective criteria for the past 5 years.
4.4.2 Predicted Future Background Air Quality
The background air pollutant concentrations predicted by the PATH model
(i.e. Pollutants in the Atmosphere and their Transport over Hong Kong) in
different areas within the Assessment Area in Year 2020 are presented in Table
4.11.
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Table 4.11 Background Air Pollutant Concentrations Predicted by the PATH Model in
Year 2020
PATH
Grid
Concentration of Pollutants (µg m-3) (a)
19th
highest
1-hour
NO2
Annual
NO2
4th
highest
24-hour
SO2
4th
highest
10-min
SO2 (b)
10th
highest
24-hour
RSP
Annual
RSP
10th
highest
8-hour
O3
Max.
1-hour
CO
Max.
8-hour
CO
Yuen Long
1837 140 27 28 203 84 43 97 1612 1375
1838 153 28 28 217 83 44 101 1785 1383
Tung Chung
1225 125 24 36 160 78 39 93 1265 1091
1226 159 29 38 176 78 39 89 1449 1100
Tuen Mun
1433 150 29 31 173 85 43 101 1479 1187
1434 146 29 32 202 86 44 103 1491 1202
1533 130 23 29 180 82 42 105 1465 1069
1534 132 24 28 201 84 42 106 1514 1186
Butterfly Estate
1332 141 30 35 175 83 43 102 1530 1080
1432 147 29 34 153 83 42 100 1452 1117
Lau Fau Shan
1236 135 24 41 283 87 44 109 1891 1182
1338 138 24 43 325 83 43 107 1719 1253
1640 144 24 41 234 84 44 104 2004 1375
Lung Kwu Tan
1034 138 27 44 247 82 42 110 1694 1114
1133 127 26 36 212 80 41 111 1495 1087
1136 138 24 41 321 84 43 113 1978 1205
Tin Shui Wai
1539 147 24 38 271 84 44 104 1804 1314
1638 132 26 33 222 83 43 106 1785 1314
1639 137 25 34 243 84 43 102 1856 1343
Prevailing
AQOs
200 40 125 500 100 50 160 30,000 10,000
Notes:
(a) Predicted concentrations are adjusted to a reference condition of 293K and 101.325 kPa.
(b) The multiplicative factor for the stability class calculated for each hour was applied to the 1-hour SO2
concentrations to estimate the 10-minute SO2 concentrations.
As shown in Table 4.11, all the predicted background air pollutant
concentrations in different areas in Year 2020 comply with the relevant AQO
criteria.
4.5 POTENTIAL SOURCES OF IMPACT
4.5.1 Construction Phase
The Project Site and all construction activities associated with the construction
of the Project will be located within the existing boundaries of the BPPS. The
construction of the Project will include the following key activities:
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Site clearance and preparation;
Construction of up to two additional CCGT units and other associated
facilities and buildings;
Construction of cooling water intake facility; and
Construction of cooling water discharge facility.
No major earthworks or site formation works will be required during the
construction of the Project as the site has already been formed.
Soil excavation, materials handling, truck movements and wind erosion from
open stockpiling of dusty materials within the Project Site have been
identified to be the potential dust generating activities.
Dust in terms of TSP, RSP (PM10) and FSP (PM2.5) are the potential key air
emissions during the construction of the Project.
Tentatively, the construction of the first CCGT unit is expected to last for
about 42 months and is scheduled to commence in the second half of 2016.
The construction of the second CCGT unit is anticipated to also last for about
42 months and commence after 2019, when the first CCGT unit will be in
operation. The normal working hours for land-based works are expected to
be 24-hours a day from Monday to Sunday (including public holidays).
4.5.2 Operation Phase
During the operation phase of the Project, emissions from the associated
stacks of the CCGT units will occur. Other sources in the vicinity of the
Project Site which emit the same air pollutants as the proposed additional
CCGT units have also been identified. The proposed design capacity of the
additional CCGT units is up to 600MW. For the purpose of the air quality
impact assessment, the upper (600MW class) and lower (440MW class) ranges
of the generation capacity have been considered.
Stack Emissions from the Project
Stack emissions from the operation of the proposed additional CCGT units are
the major air emission sources of the Project during the operation phase.
Typically, the CCGTs will be fuelled using natural gas. During combustion
of natural gas, the potential emissions to atmosphere from the stacks are:
NO2;
NH3 (ie, by-product from the built-in SCR process for reducing NOx
emission).
SO2;
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RSP (PM10);
FSP (PM2.5); and
CO.
There is potential that during back-up operation, the CCGT unit would be
fuelled using ultra-low sulphur diesel (ULSD). Under these circumstances,
the potential emissions to atmosphere would be:
NO2;
SO2;
RSP (PM10);
FSP (PM2.5); and
CO.
The key air pollutants of concern to be assessed quantitatively include NO2,
SO2, RSP (PM10) and FSP (PM2.5). Emissions of CO from the proposed CCGT
units are considered negligible. Monitoring results from EPD’s AQMS show
that background CO concentrations are consistently well below the respective
criteria. With respect to the compliance of the cumulative impact with the
relevant AQO criteria, CO is therefore considered to be non-critical and it is
not necessary to be quantitatively assessed.
Emissions from Other Air Emission Sources in the Vicinity of the Project Site
A number of major air emission sources in the vicinity of the Project Site have
been identified which emit the same air pollutants as identified for the CCGT
units. This has the potential to result in cumulative air quality impact. The
identified sources are:
Stack emissions from existing CPPS, including Castle Peak “A” Power
Station (CPA) and Castle Peak “B” Power Station (CPB);
Stack emissions from existing BPPS;
Stack emissions from Sludge Treatment Facilities (STF), WENT Landfill
(both existing landfill and future extension); and
Major air emissions from industrial facilities along Lung Mun Road such
as Shiu Wing Steel Mill, Green Island Cement and EcoPark in Tuen Mun
Area 38.
The key potential air pollutants of concern associated with these major air
emission sources include NO2, SO2, RSP (PM10) and FSP (PM2.5).
Traffic Emissions from Major Road Networks within the Assessment Area
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Vehicles burn hydrocarbons as their main power source. Burning of
hydrocarbons produces similar air pollutants to those that will be released
from the CCGT stacks.
CO is the pollutant emitted from the incomplete combustion of the fossil fuel
of the vehicles and road transport is one of the contributors in the emission of
CO. With reference to the “Air Quality in Hong Kong 2014 – Preliminary
Report” published by EPD, the highest recorded 1-hr averaged CO
concentration at the AQMSs within the Assessment Area in 2014 was
2,610µgm-3 (1 ) which is only 8.7% of the relevant AQO criterion (i.e.
30,000µgm-3). With respect to the compliance of the cumulative impact with
the relevant AQO criteria, CO is therefore considered to be non-critical and it
is not necessary to be considered in the assessment.
According to the “Cleaning the Air at Street Level” webpage within EPD’s
website (2), ULSD with a sulphur content of only 0.005% is the statutory
minimum requirement for motor vehicle diesel. In addition, as from 1 July
2010, EPD has tightened the statutory motor vehicle diesel and unleaded
petrol specifications to Euro V level, which further tightened the sulphur
content in motor vehicle diesel from 0.005% to 0.001%. With the use of ULSD
and petrol with better quality, the road transport contributed only 0.16% of
total SO2 produced (ie, 31,280 tonnes) in 2013 as indicated in the 2013 Hong
Kong Emission Inventory Report (3) published in June 2015. It is therefore
clearly indicated that SO2 emission from vehicular emission is negligible and it
is considered not necessary to predict SO2 impact from vehicular emission.
NO2, RSP (PM10) and FSP (PM2.5) have therefore been identified as the
emissions with potential to cause cumulative impacts with the proposed
additional CCGT units.
4.6 ASSESSMENT METHODOLOGY AND ASSUMPTIONS (OPERATION PHASE)
4.6.1 General Approach
A number of Areas of Influence (AoIs) within the 15 km Assessment Area
have been identified based on the evaluation of impact from Project emission
only and the review of monitoring data from AQMSs within the Assessment
Area operated by CLP and EPD in Section 4.6.3. Cumulative air quality
impact assessment has been carried out for ASRs within the identified AoIs.
The ASRs within the AoIs to be included in the cumulative impact assessment
were determined based on the principle that they are located near the major
roads or near the AQMS, such that these ASRs can reasonably and
conservatively represent the cumulative air quality impact within that
particular AoI.
(1) Air Quality Statistical Summary in Hong Kong 2014
(http://www.aqhi.gov.hk/api_history/english/report/files/AQR2014%20summary_en0707.pdf)
(2) http://www.epd.gov.hk/epd/english/environmentinhk/air/prob_solutions/cleaning_air_atroad.html
(3) http://www.epd.gov.hk/epd/sites/default/files/epd/2013EIReport_eng_1b.pdfd
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A three tier approach recommended in the EPD’s Guidelines on Assessing the
'Total' Air Quality Impacts was followed to assess the potential cumulative air
quality impact at the identified AoIs:
1st tier: Project contribution;
2nd tier: Major emission sources around the Project Site and within the
AoIs; and
3rd tier: General background.
The three tier approach has been adopted for the opening year of the Project
(2020) as it is anticipated that background concentrations resulting from roads
and external regional sources will continue to improve in the future. The
opening year, therefore provides a conservative assessment as background
concentrations will be the highest for that year.
The three tier approach therefore provides a conservative cumulative air
quality impact assessment that has separately considered:
Stack emissions from the additional CCGT units (i.e. Project
contribution);
Emissions from other major emission sources in the vicinity of the Project
Site;
Vehicular emissions from major roads within the AoIs for 2020 vehicle
volumes and fleet composition; and
PATH background in 2020 provided by the EPD.
It should be noted that the 2020 PATH background has included the emissions
from a number of major emission sources in the vicinity of the Project Site,
(including the BPPS, CPA, CPB, Green Island Cement, the proposed
Integrated Waste Management Facility (IWMF) and marine emissions from
River Trade Terminal), emissions from airport operation in Tung Chung, as
well as vehicular emissions. Other additional major emission sources,
including the Sludge Treatment Facilities (STF), WENT landfill, Shiu Wing
Steel Mill, EcoPark, Permanent Aviation Fuel Facility (PAFF), Butterfly Beach
Laundry and Flare at Pillar Point Valley Landfill (PPVL) have been identified
in the vicinity of the Project Site and their emissions have also been included
in the PATH model run to update the 2020 PATH background.
Short-term cumulative impact assessment
For the assessment of cumulative short-term impact, the EPD 2020 PATH
background has been updated to exclude the vehicular emissions from major
roads within the AoIs. This is to avoid double counting of vehicular
emissions and provide a more conservative assessment of the cumulative air
quality impact at ASRs by separate modelling of the road traffic emission
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within the AoIs using the CALINE4 model. For conservative assessment of
air quality impact arising from the Project, emissions from the proposed
CCGT units have been modelled using ISCST3 and it was assumed that the
proposed CCGT units are operating at the emission limits specified in the Best
Practicable Means for Electricity Works (Coal-fired Plant, Gas-fired Gas Turbine, and
Oil-fired Gas Turbine (Peak Lopping Plant)) (BPM 7/1 (2014)).
Long-term cumulative impact assessment
For the assessment of cumulative long-term impact, the emissions from the
CAPCO’s power generation facilities have to take account of the emission cap
as specified in the 5th Technical Memorandum for Emission Allowances (hereafter
referred to as 2020 Emission Cap). A number of operating scenarios for the
CAPCO’s power generation facilities (including with and without the Project
scenarios, which consider CAPCO’s power generation facilities as a whole)
have been established to assess the potential improvement (i.e. potential
reduction in cumulative air quality impacts) as a result of the displacement of
coal-fired power generation from CPPS and gas-fired generation from BPPS or
gas-fired power generation from BPPS only under various scenarios.
Emissions from the proposed CCGT units, BPPS, CPA and CPB have been
modelled using ISCST3 in order to facilitate the modelling setup and runs for
assessing annual emission loading from the aforementioned CAPCO’s power
generation facilities under a number of operating scenarios. In addition,
results of the ISCST3 modelling of the long-term air quality impact due to
emissions from the CAPCO’s power generation facilities are expected to be
comparable to those of the PATH modelling as the ASRs within the concerned
AoIs are relatively far away from emission sources of the CAPCO’s power
generation facilities. To avoid double counting of the emissions from BPPS,
CPA and CPB and the vehicular emissions within the AoIs, PATH model run
has been undertaken to update the EPD 2020 PATH Background by excluding
the vehicular emissions from major roads within the AoIs as well as stack
emissions from BPPS, CPA and CPB.
4.6.2 Operation of the Project
The additional CCGT unit(s) are intended to operate as a priority plant and
will be topped up by BPPS and CPPS to meet the future electricity generation
demand.
The stack design and emissions of the additional CCGT units will meet the
requirements set out in BPM 7/1 (2014) and are summarised in Table 4.12.
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Table 4.12 BPM 7/1 (2014) Stack Emission Requirement for Criteria Pollutants for Gas-
fired and Oil-fired Gas Turbine
Parameter BPM Requirement (c)
Gas-fired Oil-fired
Flue gas temperature > 80C > 80C
Flue gas velocity > 15 m s-1 > 15 m s-1
Emission Limit : (a)
Particulates 5 mg Nm-3 10 mg Nm-3
Sulphur dioxide (SO2) 15 mg Nm-3 (b) 3 mg Nm-3 (b)
Nitrogen oxides (NOx) 5 mg Nm-3 150 mg Nm-3
Notes:
(a) All emission limits are expressed as at 15% O2, 0C, 101.325kPa, dry condition.
(b) SO2 emission limit during oil-fired operation has made reference to the fuel oil sulphur
content requirement stipulated in the BPM 7/1 (2014), i.e. not more than 0.005% by
weight. SO2 emission limit during gas-fired operation is based on t he SO2 emission
limit stipulated in the BPM 7/1 (2014) which has made reference to the natural gas total
sulphur content stipulated in the PRC National Standards GB 17820-2012 for Class II, i.e.
not more tha n 200 mg/Nm3. The actual total gas sulphur content recorded in the past
years is well below the Class II standard.
(c) This provides a conservative assessment of the potential impact as ASRs. It should be
noted that it is anticipated that the actual emission will be lower than the limit level.
The installed capacity of each additional CCGT unit will be in the range of
440MW to 600MW Class. The stack diameter for 440MW unit is about 7m
and that for 600MW is about 8m. The stack height will be between 80m and
100m above ground.
During normal operation (when burning natural gas), the maximum flue gas
flow per additional CCGT unit is estimated to be about 2,660,000 Nm3 hr-1 for
440MW units or 3,350,000 Nm3 hr-1 for 600MW units (expressed as at 15% O2,
0C, 101.325kPa and dry condition).
When the additional CCGT unit(s) are fuelled by ULSD, the emissions will
also meet the requirements set out in BPM 7/1 (2014) which are summarised in
Table 4.12 above. Oil-fired operation may be required under emergency
situation (e.g. insufficient gas supply). Based on past experience, generation
by oil-firing due to emergency occurred infrequently (1 ) and the longest
duration for continuous oil-firing lasted for less than a week. ULSD may also
be used during commissioning and testing of the additional CCGT’s fuel
transfer capability of which the duration is expected to be less than three
hours for each testing. Hence, prolonged use of ULSD by the additional
CCGT unit(s) for generation is not anticipated.
4.6.3 Identification of AoIs for Cumulative AQIA
AoIs have been identified by two approaches:
Impact from Project contribution only; and
(1) Generation by oil-firing due to emergency occurred less than five times in a year during 2013 and 2014.
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Review of monitoring data recorded at AQMSs within the Assessment
Area operated by CLP and EPD in the recent past 5 years (ie 2010 – 2014).
Impact from Project Contribution Only
A significant impact level (SIL) used in the US (1) has been adopted to identify
the AoI. As NO2 is considered the potential key air pollutant associated with
the operation of the CCGT units, NO2 impact arising from the operation of the
CCGT units has been assessed and reviewed against the SIL. If the predicted
hourly averaged NO2 concentration at the ASRs contributed from the Project
emission is greater than 3.5% of the respective hourly NO2 criterion or the
predicted annual averaged NO2 is greater than 1% of the respective annual
NO2 criterion, a 500 m area from that particular ASR would be classified as an
AoI. All representative ASRs within the 15km Assessment Area as identified
in Table 4.2 have been assessed.
A stack height of between 80m and 100m above ground for the two additional
CCGT units (440MW or 600MW per unit) is being considered by CAPCO.
NO2 concentrations at the ASRs from the emissions of one or two additional
CCGT units during normal operation have been predicted using the EPD’s
recommended air dispersion model, ISCST3 (version 02035). Emissions from
one or two additional CCGT units with two power outputs, 440MW and
600MW, have been modelled at two stack heights, ie 80m and 100m above
ground. The assessment of impacts from the Project emissions only was
based on the information on stack parameters provided by CAPCO and the
requirements stipulated in BPM 7/1 (2014). The minimum exit velocity,
minimum exit temperature and NOx emission limit stipulated in BPM 7/1
(2014) have been adopted to assess the reasonable worst-case scenario in
accordance with the requirement of Section 4.3.1 (b)(v) of EIAO-TM. The
stack parameters and emission information are summarised in Table 4.13.
The model input parameters and assumptions are summarised in Table 4.14.
A detailed emission inventory of the additional CCGT units is provided in
Annex 4B.
Table 4.13 Stack Parameters and NOx Emissions of Each Additional CCGT Unit
Stack / Emission Information 440MW
CCGT Unit (b)
600MW
CCGT Unit (b)
Remarks
Stack Diameter per flue (m) 7 8 Given by CAPCO
Stack Height (mAG) 80 or 100 80 or 100 Given by CAPCO
Flue Gas Efflux Velocity (m s-1) 15 15 BPM 7/1 (2014)
Flue Gas Exit Temperature (oC) 80 80 BPM 7/1 (2014)
Flue Gas Flow Rate (Nm3 hr-1) (a) 2,660,000 3,350,000 Given by CAPCO
Emission Concentration of NOx (mg Nm-3) (a) 5 5 BPM 7/1 (2014)
Emission Rate of NOx (g s-1) 3.70 4.66 By calculation
(1) SIL for 1-hr NO2 is reference to Guidance Concerning the Implementation of the 1-hour NO2 NAAQS for the Prevention of
Significant Deterioration Program, August 23, 2010. SIL for annual average NO2 is reference to US Code of Federal
Regulations 40CFR 51.165(b)(2).
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Stack / Emission Information 440MW
CCGT Unit (b)
600MW
CCGT Unit (b)
Remarks
Notes:
(a) expressed at 15% O2, 0 degree Celsius, 101.325kPa, dry condition.
(b) Up to two CCGT units will be built.
Table 4.14 ISCST3 Model Input Parameters and Assumptions
Input Parameters &
Assumptions
Descriptions
Air dispersion model ISCST3
Operation hours of stacks 24 hours
Meteorological data PATH Model – 2010 MM5 data
Mixing heights in MM5 which are lower than the lowest
recorded mixing height by the Hong Kong Observatory (ie
121m) in 2010 were adjusted to 121m.
Stability class calculated by PCRAMMET (version 99169)
Mode of dispersion Urban or rural dispersal mode depending on the land uses in
which the ASRs are located. Dispersal mode used for each
PATH grid in which the ASRs are located is presented in
Annex 4A.
The predicted 19th highest hourly and annual averaged NO2 concentrations at
the identified ASRs were checked against the respective criteria and the SIL to
determine the AoI.
Review of the Concentrations of NO2 Measured at AQMSs Operated by CLP and
EPD within the Assessment Area in the Recent Past 5 Years (ie 2010 – 2014)
Five (5) of CLP’s AQMSs at Butterfly Estate, Tuen Mun Clinic (San Hui in 2013
or before), Tin Shui Wai, Lung Kwu Tan and Lau Fau Shan and three (3) of
EPD’s AQMSs at Tuen Mun, Yuen Long and Tung Chung were identified
within the Assessment Area. In terms of background air quality, NO2 level is
considered key air pollutant of concern with common hourly and annual
exceedances at some AQMSs. Therefore, the measured NO2 concentrations
recorded at each AQMS in the past 5 years (ie, 2010 – 2014) have been
reviewed. If the 19th highest hourly NO2 concentrations or annual averaged
NO2 concentrations measured at a particular AQMS exceed the respective
hourly or annual NO2 criteria, a 500 m area around that AQMS would be
classified as an AoI.
Cumulative air quality impact assessment was then carried out for the
representative ASRs located within the identified AoIs.
4.6.4 Stack Emissions from the Additional CCGT Units
Short-term Impact (10-minute, hourly and daily averaging)
As mentioned in Section 4.5.2, the key air pollutants of concern to be
quantitatively assessed during normal operation and back-up operation of the
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additional CCGT units include NO2, SO2, RSP (PM10) and FSP (PM2.5). For
NH3 which is a non-criteria pollutant, its potential health impact has been
addressed in Section 14 of this EIA Report.
The emissions requirement stipulated by BPM 7/1 (2014) for NOx, SO2 and
particulates has been adopted as the worst-case scenario emissions. The
emission rates of the air pollutants of concern were calculated based on stack
information provided by CAPCO and the emission requirements from BPM
7/1 (2014), as shown in Table 4.12. Different modelling scenarios which
consider the reasonable worst-case scenarios during the operation of one or
two additional CCGT units have been assessed for short-term air quality
impact and are summarised in Table 4.15.
Table 4.15 Operation Scenarios Adopted for Short-term AQIA
Modelling Scenario Description
1 additional CCGT unit
440MW normal Normal operation of one 440MW CCGT units
600MW normal Normal operation of one 600MW CCGT units
440MW back-up Back-up (oil-fired) operation of one 440MW CCGT units
600MW back-up Back-up (oil-fired) operation of one 600MW CCGT units
2 additional CCGT units
440MW normal Normal operation of two 440MW CCGT units
600MW normal Normal operation of two 600MW CCGT units
440MW back-up Back-up (oil-fired) operation of two 440MW CCGT units
600MW back-up Back-up (oil-fired) operation of two 600MW CCGT units
The stack parameters and emission information for normal and back-up
operation are summarised in Table 4.16. The model input parameters and
assumptions are summarised in Table 4.14. The stack locations of the
additional CCGT units are shown in Figure 4.2. A detailed emission
inventory of the additional CCGT units is provided in Annex 4B. For short-
term impact assessment, hourly NO2, 10-minute and daily SO2, daily RSP
(PM10) and daily FSP (PM2.5) have been assessed according to the prevailing
AQOs.
Table 4.16 Stack Parameters and Emission Information of Each Additional CCGT Unit
Operation
Mode
Stack / Emission Information 440MW
CCGT Unit (e)
600MW
CCGT
Unit (e)
Remarks
Stack Diameter per flue (m) 7 8 Given by CAPCO
Stack Height (mAG) 80 or 100 (f) 80 or 100 (f) Given by CAPCO
Gas-fired Flue Gas Efflux Velocity (m s-1) 15 15 BPM 7/1 (2014) (c)
Flue Gas Exit Temperature (ºC) 80 80 BPM 7/1 (2014) (c)
Flue Gas Flow Rate (Nm3 hr-1) (a) 2,660,000 3,350,000 given by CLP
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Operation
Mode
Stack / Emission Information 440MW
CCGT Unit (e)
600MW
CCGT
Unit (e)
Remarks
Emission Concentration
NOx (mg Nm-3)
SO2 (mg Nm-3)
PM10/PM2.5 (mg Nm-3) (b)
5
15
5
5
15
5
BPM 7/1 (2014) (c)
BPM 7/1 (2014) (c) (d)
BPM 7/1 (2014) (c)
Emission Rate
NOx (g s-1)
SO2 (g s-1)
PM10/PM2.5 (g s-1) (b)
3.69
11.08
3.69
4.66
13.96
4.66
By calculation
By calculation
By calculation
Oil-fired Flue Gas Efflux Velocity (m s-1) 15 15 BPM 7/1 (2014) (c)
Flue Gas Exit Temperature (ºC) 80 80 BPM 7/1 (2014) (c)
Flue Gas Flow Rate (Nm3 h-1r) (a) 2,800,000 3,700,000 given by CLP
Emission Concentration
NOx (mg Nm-3)
SO2 (mg Nm-3)
PM10/PM2.5 (mg Nm-3) (b)
150
3
10
150
3
10
BPM 7/1 (2014) (c)
BPM 7/1 (2014) (c) (d)
BPM 7/1 (2014) (c)
Emission Rate
NOx (g s-1)
SO2 (g s-1)
PM10/PM2.5 (g s-1) (b)
116.67
2.33
7.78
154.17
3.08
10.28
By calculation
By calculation
By calculation
Notes:
(a) Expressed at 15% O2, 0 degree Celsius, 101.325kPa, dry condition.
(b) It is assumed that emission concentration and emission rate of FSP (PM2.5) is the same as
that of RSP (PM10) as a conservative approach.
(c) This provides a conservative assessment for the potential impact to the ASRs
(d) SO2 emission limit during oil-fired operation has made reference to t he fuel oil sulphur
content requirement stipulated in the BPM 7/1 (2014), i.e. not more than 0.005% by
weight. SO2 emission limit during gas-fired operation is based on the SO2 emission limit
stipulated in the BPM 7/1 (2014) which has made reference to the natural gas total
sulphur content stipulated in the PRC National Standards GB 17820 -2012 for Class II, i.e.
not more than 200 mg/Nm3. The actual total gas sulphur content recorded in the past
years is well below the Class II standard.
(e) Up to two CCGT units will be built.
(f) Based on the assessment of Project impact only (Section 4.6.3), the Project contributions at
the ASRs at the stack height of 80m or 100m would be predicted. As a conservative
approach, the stack height of the new CCGT unit (80m or 100m) which causes the higher
impact at the ASRs would be considered in the cumulative short-term impact assessment.
Long-term Impact (annual averaging)
As the first and second CCGT units are assumed to be in operation by end
2019 and after 2019, respectively, CAPCO has considered a number of
operation scenarios of CAPCO’s power generation facilities as a whole (i.e.
additional CCGT units, BPPS, CPA and CPB) in 2020. Different operation
scenarios meeting the 2020 Emission Cap were developed. These operation
scenarios, which are the potential operation scenarios of the CAPCO power
generation facilities (with or without Project) in 2020, were adopted for
modelling purposes and are described in Table 4.17.
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A total of 9 scenarios have been assessed. Scenario 1 is the base case which
considers CAPCO’s operation without Project in 2020. The remaining
scenarios are “with Project” scenarios (i.e. 2a, 2b, 2c, 2d, 3a, 3b, 3c and 3d),
which consider the displacement of existing CAPCO power generation by 1 or
2 additional CCGT units (440MW or 600MW (1)). The send-out from the
additional CCGT unit(s) is assumed to displace the send-out from existing
plants (displacing coal-fired generation from CPPS and gas-fired generation
from BPPS or gas-fired generation from BPPS only). The total send-out of the
individual “With Project” scenarios (i.e. additional CCGT unit(s) + CPA + CPB
+ BPPS) are assumed to be the same as the total send-out of the “Without
Project” scenario (i.e. CPA + CPB + BPPS).
Displacing Both Coal-fired and Gas-fired Generation Scenarios (Scenarios 2b,
2d, 3b and 3d):
Under normal operation, the additional CCGT unit(s) will be operated as
a priority plant. The send-out from the new CCGT unit(s) will normally
displace both the coal-fired send-out from CPPS and gas-fired send-out
from BPPS. The scenarios are established to represent potential future
operation regimes under normal situation. The scenarios have assumed
maximum total emission loadings from the existing CPA, CPB and BPPS
and the additional CCGT unit(s) to be at 2020 emission cap levels which
represent worst case in terms of annual emission loadings. The
scenarios are considered to represent reasonably worst case of potential
future operation regimes.
Displacing Gas-fired Generation Only Scenarios (Scenarios 2a, 2c, 3a and 3c):
The displacing gas generation only scenarios are also included in the
assessment to demonstrate the potentially least improvement in annual
emission performance and acceptability of environmental impact to ASRs
under worst case situation. The scenarios have assumed no additional
gas-fired generation with the implementation of the additional CCGT
unit(s); and the additional CCGT unit(s) and existing BPPS units are
dispatched with the same priority. However, it should be noted that
under normal circumstances, the additional CCGT unit(s) will be
operating as a priority plant over the existing gas-fired units in BPPS.
The operation scenarios adopted for modelling are described in Table 4.17.
(1) The range of CCGT capacity under consideration by CAPCO is between 440MW and 600MW and therefore CCGT
capacities of 440MW and 600MW are included in the assessment.
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Table 4.17 Operation Scenarios Adopted for Long-term AQIA
Operation Scenario Description
1 CAPCO operation without Project
2a 1x 440MW CCGT send-out displacing gas-fired send-out from BPPS
2b 1x 440MW CCGT send-out displacing both existing coal-fired send-
out from CPPS and gas-fired send-out from BPPS
2c 1x 600MW CCGT send-out displacing gas-fired send-out from BPPS
2d 1x 600MW CCGT send-out displacing both existing coal-fired send-
out from CPPS and gas-fired send-out from BPPS
3a 2x 440MW CCGT send-out displacing gas-fired send-out from BPPS
3b 2x 440MW CCGT send-out displacing both existing coal-fired send-
out from CPPS and gas-fired send-out from BPPS
3c 2x 600MW CCGT send-out displacing gas-fired send-out from BPPS
3d 2x 600MW CCGT send-out displacing both existing coal-fired send-
out from CPPS and gas-fired send-out from BPPS
A breakdown of anticipated annual pollutant emission allocations in 2020 for
each operation scenario as shown in Table 4.17 is presented in Annex 4B. A
detailed emission inventory and stack configurations are provided in Annex
4B. A breakdown of the send-out and annual pollutant emission allocations
in 2014 reflecting the prevailing situation are also provided in Annex 4B for
reference. The send-out from the additional CCGT unit(s) is assumed to
displace the send-out from existing plants in the long-term scenarios. The
total send-out of the “with Project” scenarios (i.e. Scenario 2a-2d and 3a-3d) is
assumed to be the same as the total send-out of the “without Project” scenario
(i.e. Scenario 1).
According to the requirement set out in Clause 4(ii) of Appendix A of the EIA
Study Brief, any reduction of cumulative air quality impact during normal
operation of the Project shall be quantified. As presented in Annex 4B, for all
“with Project” scenarios, there will be an overall reduction in the total annual
emission loading in NOx, SO2 and RSP (PM10) from CAPCO power generation
facilities when compared with the “without Project” scenario (i.e. Scenario 1).
Substantial reductions in total annual emission loading are demonstrated in
the displacing both coal-fired and gas-fired generation scenarios (i.e. Scenarios
2b, 2d, 3b and 3d). For the one additional CCGT scenarios (i.e. Scenarios 2b
and 2d), significant reduction in emissions are predicted ranging between 8.8
to 15.6% for 440MW CCGT and 10.7 to 19.4% for 600MW CCGT when
comparing with the 2020 emission cap (see Tables 2 and 4 of Annex 4B).
Further reduction in emissions are shown in the two additional CCGT
scenarios (i.e. Scenarios 3b and 3d), ranging between 14.1 to 25.9% for 440MW
CCGT and 17.8 to 33.1% for 600MW CCGT (see Tables 3 and 5 of Annex 4B).
For the displacing gas-fired generation only scenarios (i.e. Scenarios 2a, 2c, 3a
and 3c), reduction in emissions are still demonstrated under worst case
situation with least reduction ranging between 0.4 to 2.3% for one 440 MW
CCGT (see Tables 2 of Annex 4B).
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Electricity is not generated equally over a 24 hour period, with higher
electricity demand required during the daytime compared to the night-time.
To reflect this daily profile, for each operation scenario, a diurnal emission
pattern was assumed to reasonably reflect a higher emission during
“daytime” and lower emission during “night-time” throughout the course of a
day where applicable. To estimate the profile, the daily averaged emissions
of each CAPCO’s power generation facility were estimated by dividing the
annual emission loading as shown in Annex 4B by 365 days. A day-time and
night-time factor was applied to the daily averaged emissions of each
CAPCO’s power generation facility to estimate the hourly emission rates
during “daytime” and “night-time” throughout the course of a day. The
averaged exit velocity obtained from 2013 and 2014 data for BPPS, CPA and
CPB was adopted in the modelling for long-term impact.
Assessment parameters for long-term air quality impact include annual NO2,
annual RSP (PM10) and annual FSP (PM2.5) according to the prevailing AQOs.
4.6.5 Emissions from Other Air Emission Sources in the Vicinity of the Project Site
Emissions from other major air emission sources in the vicinity of the Project
Site (1 ) have been considered in the cumulative impact assessment. The
emission inventory and stack information of these air emission sources have
been referenced the best available information from relevant SP licences and
approved EIA Reports. Emissions from these other major air emission
sources in the vicinity of the Project Site have been modelled by PATH (refer
to Section 4.6.7). The emission sources included and their emission
information adopted in the PATH model have been agreed with EPD prior to
conducting the PATH modelling. The emission inventory of these major air
emission sources and a figure showing the locations of the key air emission
sources are provided in Annex 4C.
4.6.6 Traffic Emissions from Major Road Networks within the AoIs
As mentioned in Section 4.5.2, NO2, RSP (PM10) and FSP (PM2.5) are the major
air pollutants of concern from vehicular emissions. It should be noted that
no additional traffic will be generated from the operation of the additional
CCGT units. Vehicular emissions of major road networks within the
identified AoI have been quantitatively assessed as 2nd tier contributions to the
cumulative air quality impact.
Representative major roads were identified within the AoI. Projected hourly
traffic flows and vehicle composition of 16 vehicle types for 24 hours of each
identified road within the AoI (except Tung Chung) in 2020, 2025, 2030 and
2035 (15 years after commencement of operation of the Project) were provided
by the Project’s traffic consultant. The hourly averaged vehicle speed of each
(1) Other key air emission sources in the vicinity of the Project Site (i.e. BPPS, STF, existing WENT landfill and WENT
landfill extension), together with some key emission sources along Lung Mun Road (i.e. CPPS, Green Island
Cement, Shiu Wing Steel Mill, Eco Park in Tuen Mun Area 38, Permanent Aviation Fuel Facility (PAFF), Butterfly
Beach Laundry, Flare at Pillar Point Valley Landfill (PPVL)).
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identified road was also provided by the Project’s traffic consultant. The
traffic flows and speeds are provided in Annex 4D. The traffic forecast in
Butterfly Estate, Tin Shui Wai, Tuen Mun and Yuen Long AoIs have been
endorsed by Traffic Department and the approval letters are included in
Annex 4D. Reference was made to the Tung Chung New Town Development
Extension EIA Report for the traffic flows and speeds for the identified roads
within the Tung Chung AoI, where the traffic flow forecast was in 2023.
An EPD recommended model, EMFAC-HK v2.6, was used to predict the
emissions per vehicle kilometre (emission factors) of NOx, RSP (PM10) and FSP
(PM2.5) for the 16 vehicle types. Emission factors were estimated for the Year
2020, 2025, 2030 and 2035. “EMFAC” mode was used for the model run and
the average ambient temperature and relative humidity recorded at the HKO
Weather Station nearest to the AoI in 2014 were used. The information for
each weather station is presented in Table 4.18 along with the relevant AoIs.
Table 4.18 2014 Weather Data for EMFAC Run
HKO Weather
Station
Average
Temperature (°C)
Average Relative
Humidity (%)
AoI
Tuen Mun 23 77 Tuen Mun, Butterfly Estate
Wetland Park 23 78 Tin Shui Wai, Yuen Long
HKIA 24 70 Tung Chung
The emission factors for the 16 vehicle types in 2020, 2025, 2030 and 2035 and
the calculation of the composite emission rates for each road are presented in
Annex 4D.
A sensitivity analysis was carried out to determine the worst year in terms of
vehicular emissions for cumulative impact assessment. The total emission
rates of NOx for Years 2020, 2025, 2030 and 2035 were compared. The year
with the highest emission rate of NOx was selected as the worst year for the
cumulative impact assessment. The Year 2020 was predicted to have the
highest emission rate of NOx and was identified as the worst year for
cumulative impact assessment. The results of the sensitivity analysis are
provided in Annex 4D.
Model Assumptions for Open Road Vehicle Emission
An EPD recommended air dispersion model, CALINE4, was used for
predicting NO2, RSP (PM10) and FSP (PM2.5) impacts arising from the open
road vehicular emissions within the AoIs. The configurations of the major
existing roads used in the model were generated according to the road
alignments. Since the highest road height allowed in the input into
CALINE4 model is limited at 10m, any road with road height greater than
10m was set at a height of 10m in the CALINE4 model. The alignments and
configurations (road heights and widths) of the major existing roads within
the AoIs are provided in Annex 4D.
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The surface roughness length is closely related to the land use characteristics
of the Assessment Area and associated with the roughness element height.
As a first approximation, the surface roughness can be estimated as 3% to 10%
of the average height of physical structures. Typical values used for rural
and urban areas are 100cm and 370cm, respectively (1). Relevant surface
roughness heights used in CALINE4 model run for each PATH grid have been
identified and are consistent with those adopted for ISCST3 model. Wind
directional variability was calculated using Equation 4-1.
Equation 4-1 Calculation of Wind Directional Variability According to Stability Class
(Irwin, J.S., 1980) (2)
So = S × (Zo/15cm)0.2
Where
Zo = is the surface roughness length (in cm) of the PATH grid;
So = is the standard deviation of the horizontal wind direction Fluctuations (in degrees)
S = is the standard deviation of the horizontal wind direction fluctuations (in degrees) for an
aerodynamic surface roughness length of 15cm with reference to Irwin, J.S., 1980. S is a
function of Pasquill stability class.
The CALINE4 model input parameters and assumptions are summarised in
Table 4.19.
Table 4.19 Model Input Parameters and Assumptions for Assessment of Vehicular
Emissions
Input Parameters &
Assumptions
Descriptions
Air dispersion model CALINE4
Year of traffic flow Year 2020
Vehicle emission factors EMFAC-HK emission factors for 2020
Meteorological data PATH Model – 2010 MM5 data
Mixing heights in MM5 which are lower than the lowest
recorded mixing height by the Hong Kong Observatory
(HKO) (ie, 121m) in 2010 were adjusted to 121m.
Wind speeds in MM5 which are lower than the 0.5ms -1
recommended by t he CALINE4 model were adjusted to
0.5ms-1.
Stability class calculated by PCRAMMET (version 99169)
Calculation of wind directional va riability based on stability
class and surface roughness length
Surface roughness 100 cm for rural land use
370 cm for urban land use
The land use for each PATH grid in which the ASRs are
located is presented in Annex 4A.
(1) http://www.epd.gov.hk/epd/english/environmentinhk/air/guide_ref/guide_aqa_model_g1.html Section 3.4
(2) Dispersion Estimate Suggestion #8: Estimation of Pasquill Stability Categories. U.S. Environmental Protection
Agency, Research Triangle Park, NC. (Docket Reference No.II-B-10), Irwin, J.S., 1980.
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Model Assumptions for Portal Emissions
Sections of major roads identified in the Tuen Mun AoI were identified to
have full enclosures/deckovers, semi-enclosures, vertical and cantilevered
noise barriers. The assumptions for the alignment were based on the
available information from the approved Environmental Impact Assessment of
Traffic Improvements to Tuen Mun Road Town Centre Section (AEIAR-128/2009)
and with reference to the Permanent International Association of Road Congress
Report (PIARC, 1991). The approach adopted followed closely the
methodology contained in the approved Environmental Impact Assessment of
Traffic Improvements to Tuen Mun Road Town Centre Section (AEIAR-128/2009).
Road sections with semi-enclosures, vertical and cantilevered noise barriers
were considered as elevated open roads while full enclosures were considered
to generate portal emissions.
Air pollutants were assumed to be ejected from the portal as an air jet and the
total length of the air jet is about 100m. In each portal, two thirds of the
emissions were assumed to disperse in the first 50m of the air jet and another
third of the emissions was assumed to disperse within the second 50m.
However, the separation distance between the two full enclosures at some
locations along Tuen Mun Road is between 50m to 100m. The pollutants
were assumed to eject from the portal as an air jet such that two thirds of the
total emissions were still dispersed within the first 50m portal. If the length
of remaining open road section is less than 50m, the other one third of the total
emissions was assumed to eject within the remaining part of the open road
section and into the next enclosures. Where the separation distance between
adjacent full enclosures is less than 100m, the calculation of portal emission at
those enclosures will take into account the looping effect (see Annex 4D-6a).
The portal emissions of the full enclosures/ deckovers were calculated based
on the vehicle emission derived from the adopted fleet average emission
factors and vehicle flows in 2020. The calculations and locations of the portal
emissions generated by the enclosures are presented in Annex 4D-9.
An EPD recommended air dispersion model, ISCST3, was employed to
simulate the air quality impact of the portal emissions on the ASRs. The
model input parameters and assumptions are summarised in Table 4.20.
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Table 4.20 ISCST3 Model Input Parameters and Assumptions
Input Parameters &
Assumptions
Descriptions
Air dispersion model ISCST3
Year of traffic flow Year 2020
Vehicle emission factors EMFAC-HK emission factors in 2020
Meteorological data PATH Model – 2010 MM5 data
Mixing heights in MM5 which are lower than the lowest
recorded mixing height by the Hong Kong Observatory
(HKO) (ie, 121m) in 2010 were adjusted to 121m.
Stability class calculated by PCRAMMET (version 99169)
Mode of dispersion Urban or rural dispersal mode depending on the land uses in
which the ASRs are located. Dispersal mode used for each
PATH grid in which the ASRs are located is presented in
Annex 4A.
4.6.7 Background Air Quality
For the assessment of short-term impact, the PATH model for 2020 was re-run
to exclude emissions from vehicular emissions from major roads within AoIs.
This is to avoid double counting of vehicular emissions which have been
considered in the CALINE4 model. Stack emissions from BPPS, CPA and
CPB in the PATH model have been updated based on the pollutant emission
loading for CAPCO operation without Project (i.e. Scenario 1 of Table 4.17 –
CAPCO operation without Project). A daily emission profile for BPPS, CPA
and CPB has been used in the PATH model to reasonably reflect a higher
emission during “daytime” and lower emission during “night-time
throughout the course of the day where applicable. This daily emission
profile used is the same as that adopted for the assessment of long-term
impact as discussed in Section 4.6.4. The monthly emission profiles adopted
in the PATH model for BPPS, CPA and CPB were derived based on 2013 and
2014 historical data. In addition, a number of emission sources were added
or updated as agreed with EPD. A summary of emission sources that were
removed, added or updated in the PATH model run to derive the 2020
background air quality for short-term impact assessment is provided in Table
4.21.
For the assessment of long-term impact, in addition to removing the vehicular
emissions, emissions from the existing BPPS, CPA and CPB were also
excluded and an additional run of the PATH model for 2020 was conducted.
This is to avoid double counting of stack emissions from BPPS, CPA and CPB,
which have been modelled by ISCST3 based on a number of operation
scenarios as discussed in Section 4.6.4. Furthermore, a number of emission
sources were added or updated in the PATH model run as agreed with EPD.
A summary of emission sources that were removed, added or updated in the
PATH model run to derive the 2020 background air quality for long-term
impact assessment are summarised in Table 4.22. The detailed emission
inventory for the PATH model runs is provided in Annex 4C.
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Table 4.21 Emission Sources Removed, Added or Updated in the PATH Model Re-run to
Derive the 2020 Background Air Quality for Short-term Impact Assessment
Emission Sources Revision in the PATH Model Reference
CPA, CPB, BPPS Stack emissions were updated
based on the pollutant emission
loading for CAPCO operation
without Project
Daily emission profile was
updated.
Scenario 1 in Table 4.17 and
Annex 4B
Major roads in AoI Major roads for releva nt PATH
grids in the identified AoI were
removed
Green Island Cement Emission sources were updated SP Licence
Shiu Wing Steel Mill
(SWSM)
Emission sources were added SP Licence
EcoPark in Tuen Mun Area
38
Emission sources were added Approved EIA Report for
Expansion of Hong Kong
International Airport into a Three-
Runway System (AEIAR-
185/2014)
Permanent Aviation Fuel
Facility (PAFF)
Emission sources were added
Butterfly Beach Laundry Emission sources were added
Flare at Pillar Point Valley
Landfill (PPVL)
Emission sources were added
Sludge Treatment Facilities
(STF)
Emission sources were added Approved Air Quality and
Human Health Risk Assessment
Report in 2012 under VEP No.
366/2012 for Sludge Treatment
Facilities
Existing WENT landfill and
extension
Emission sources were added
Lamma Island Power
Station
Stack emissions were updated
based on the emission cap
4th Technical Memorandum for
Emission Allowances
Table 4.22 Emission Sources Removed, Added or Updated in the PATH Model Re-run to
Derive the 2020 Background Air Quality for Long-term Impact Assessment
Emission Sources Revision in the PATH Model Reference
CPA, CPB, BPPS Stack emission sources were
removed
Major roads in AoI Major roads for releva nt PATH
grids in the identified AoI were
removed
Green Island Cement Emission sources were updated SP Licence
Shiu Wing Steel Mill
(SWSM)
Emission sources were added SP Licence
Eco Park in Tuen Mun
Area 38
Emission sources were added Approved EIA Report for
Expansion of Hong Kong
International Airport into a Three-
Runway System (AEIAR-
185/2014)
Permanent Aviation Fuel
Facility (PAFF)
Emission sources were added
Butterfly Beach Laundry Emission sources were added
Flare at Pillar Point Valley
Landfill (PPVL)
Emission sources were added
Sludge Treatment Facilities
(STF)
Emission sources were added Approved Air Quality and
Human Health Risk Assessment
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Emission Sources Revision in the PATH Model Reference
Existing WENT landfill and
extension
Emission sources were added Report in 2012 under VEP No.
366/2012 for Sludge Treatment
Facilities
Lamma Island Power
Station
Stack emissions were updated
based on the emission cap
4th Technical Memorandum for
Emission Allowances
Hourly NO2, SO2, RSP (PM10) and O3 concentrations predicted by the re-runs
of PATH model in 2020 were adopted as the background air quality. The
PATH background air quality in 2020 incorporates other emission sources that
also contribute to the ambient air quality, which include, but are not limited
to, the proposed Integrated Waste Management Facility (IWMF), marine
emissions from River Trade Terminal and emissions from airport operation in
Tung Chung.
4.6.8 Ozone Modelling by PATH Model
Ozone is a regional air quality pollution issue. It is not a primary pollutant
directly emitted from any of the identified emission sources discussed above
but is formed by photochemical reactions of primary pollutants such as NOx
and volatile organic compounds (VOCs) under sunlight. In addition, O3 is
transported from the stratosphere to the troposphere during storm events and
generated natural by the biosphere. As NOx emission is the key concerned
pollutant from CCGT emission, the potential ozone impact within the AoI was
reviewed by running the PATH model for Year 2020 for “without Project”
scenario and “with Project” scenarios (i.e. operation of one or two additional
CCGT units). The emission sources that were added or updated in the PATH
model re-run for the “with Project” and “without Project” scenarios are
presented in Table 4.23. The detailed emission information for these emission
sources is provided in Annex 4C.
Table 4.23 Emission Sources Added or Updated in the PATH Model Re-run for
Assessment of Ozone Change
Emission Sources Revision in the PATH Model Reference
“Without Project” Scenario
CPA, CPB, BPPS Stack emissions were updated
based on the pollutant emission
loading for CAPCO operation
without Project
Scenario 1 in Table 4.17 and
Annex 4B
Green Island Cement Emission sources were updated SP Licence
Shiu Wing Steel Mill (SWSM) Emission sources were added SP Licence
Eco Park in Tuen Mun Area
38
Emission sources were added Approved EIA Report for
Expansion of Hong Kong
International Airport into a
Three-Runway System (AEIAR-
185/2014)
Permanent Aviation Fuel
Facility (PAFF)
Emission sources were added
Butterfly Beach Laundry Emission sources were added
Flare at Pillar Point Valley
Landfill (PPVL)
Emission sources were added
Sludge Treatment Facilities
(STF)
Emission sources were added Approved Air Quality and
Human Health Risk Assessment
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Emission Sources Revision in the PATH Model Reference
Existing WENT landfill and
extension
Emission sources were added Report
Lamma Island Power Station Stack emissions were updated
based on the emission cap
4th Technical Memorandum for
Emission Allowances
“With Project” Scenario – operation of one additional CCGT units (a)
CPA, CPB, BPPS Stack emissions were updated
based on the pollutant emission
loading for CAPCO operation
with Project
Scenario 2d in Table 4.17 and
Annex 4B
One additional CCGT unit Emission source were added Scenario 2d in Table 4.17 and
Annex 4B
Green Island Cement Emission sources were updated SP Licence
Shiu Wing Steel Mill (SWSM) Emission sources were added SP Licence
Eco Park in Tuen Mun Area
38
Emission sources were added Approved EIA Report for
Expansion of Hong Kong
International Airport into a
Three-Runway System (AEIAR-
185/2014)
Permanent Aviation Fuel
Facility (PAFF)
Emission sources were added
Butterfly Beach Laundry Emission sources were added.
Flare at Pillar Point Valley
Landfill (PPVL)
Emission sources were added
Sludge Treatment Facilities
(STF)
Emission sources were added Approved Air Quality and
Human Health Risk Assessment
Report Existing WENT landfill and
extension
Emission sources were added
Lamma Island Power Station Stack emissions were updated
based on the emission cap
4th Technical Memorandum for
Emission Allowances
“With Project” Scenario – operation of two additional CCGT units (b)
CPA, CPB, BPPS Stack emissions were updated
based on the pollutant emission
loading for CAPCO operation
with Project
Scenario 3d in Table 4.17 and
Annex 4B
Two additional CCGT units Emission sources were added Scenario 3d in Table 4.17 and
Annex 4B
Green Island Cement Emission sources were updated SP Licence
Shiu Wing Steel Mill (SWSM) Emission sources were added SP Licence
Eco Park in Tuen Mun Area
38
Emission sources were added Approved EIA Report for
Expansion of Hong Kong
International Airport into a
Three-Runway System (AEIAR-
185/2014)
Permanent Aviation Fuel
Facility (PAFF)
Emission sources were added
Butterfly Beach Laundry Emission sources were added.
Flare at Pillar Point Valley
Landfill (PPVL)
Emission sources were added
Sludge Treatment Facilities
(STF)
Emission sources were added Approved Air Quality and
Human Health Risk Assessment
Report Existing WENT landfill and
extension
Emission sources were added
Lamma Island Power Station Stack emissions were updated
based on the emission cap
4th Technical Memorandum for
Emission Allowances
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Emission Sources Revision in the PATH Model Reference
Notes:
(a) For the “with Project” scenario of one additional CCGT unit, comparison of Scenario 1
(without Project) and Scenario 2d (displacing both existing gas-fired generation from
BPPS and coal-fired generation from CPPS by one additional 600MW CCGT unit) would
show the highest potential change in ozone level within the AoI.
(b) For the “with Project” scenario of two additional CCGT units, comparison of Scenario 1
(without Project) and Scenario 3d (displacing both existing gas-fired generation from
BPPS and coal-fired generation from CPPS by two additional 600MW CCGT units) would
show the highest potential change in ozone level within the AoI.
The PATH modelled O3 results for “with Project” scenario and “without
Project” scenarios (i.e. operation of one or two additional CCGT units) were
compared to quantify any significant change in ozone levels within the
identified AoIs due to the Project.
4.6.9 Conversion of NOx to NO2 using Ozone Limiting Method
NOx to NO2
Two forms of nitrogen oxides are released following combustion of
hydrocarbons, NO and NO2. From industrial sources the ratio of NO to NO2
is approximately 90% to 10%, whilst from vehicles it is approximately 92.5%
NO and 7.5% NO2. These emissions are summed and termed NOX. Of the
nitrogen oxide compounds released, only NO2 is of potential concern at
concentrations in the ambient environment. Following release, NO can be
oxidised to NO2 through exposure to oxidants in the atmosphere such as
Ozone and NO2 can be broken down by sunlight.
To estimate the conversion of NOx to NO2, the Ozone Limiting Method
(OLM), the currently acceptable NOx/NO2 conversion method stated in the
EPD’s “Guidelines on Choice of Models and Model Parameters” was used. The
NO2/NOX conversions for stack emissions and vehicular emissions were
calculated using Equation 4-2 and Equation 4-3, respectively as follows:
Equation 4-2 Estimation of NO2 from total NOX for industrial emissions using the OLM
[NO2]pred = 0.1×[NOx] pred + MIN {0.9×[NOx] pred, or (46/48)×[O3] bkgd}
where
[NO2] pred = the predicted NO2 concentration
[NOx] pred = the predicted NOx concentration
MIN = the minimum of the two values within the brackets
[O3]bkgd = the representative O3 background concentration; (46/48) is the molecular weight of
NO2 divided by the molecular weight of O3
Equation 4-3 Estimation of NO2 from total NOX for road emissions using the OLM
[NO2]pred = 0.075×[NOx] pred + MIN {0.925×[NOx] pred, or (46/48) ×[O3] bkgd}
where
[NO2] pred = the predicted NO2 concentration
[NOx] pred = the predicted NOX concentration
MIN = the minimum of the two values within the brackets
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[O3]bkgd = the representative O3 background concentration; (46/48) is the molecular weight of
NO2 divided by the molecular weight of O3
For conversion of NOx to NO2 for the assessment of AoI, the predicted ozone
background concentrations in 2020 from the current PATH model have been
used.
For conversion of NOx to NO2 for the assessment of cumulative air quality
impact within the AoI, the predicted ozone background concentrations in 2020
from the PATH model re-run (refer to Section 4.6.7) have been used.
4.6.10 Cumulative Air Quality Impact at AoI
For each assessment scenario (short-term and long-term impact), the
cumulative NO2, SO2, RSP (PM10) and FSP (PM2.5) concentrations at relevant
heights of the identified ASRs within the AoI were estimated. This was
completed by adding up the hour-by-hour contributions from the modelled
emission sources and the PATH hourly background results in 2020 predicted
from the PATH model re-runs.
For the assessment of short-term impact, the cumulative air quality impact
assessment at AoI is estimated based on the following:
Cumulative impact = Emission from the additional CCGT Unit(s) + Emission
from concerned roads within the AoI + modelled PATH background 2020 (1)
For the assessment of long-term impact, the cumulative air quality impact
assessment at AoI is estimated based on the following:
Cumulative impact = Emission from the additional CCGT Unit(s) + Emission
from CPA + Emission from CPB + Emission from BPPS + Emission from
concerned roads within the AoI + modelled PATH background 2020 (2)
Different time-period averages of the 8,760 hourly results at each ASR were
then derived for comparison with the respective AQO criteria.
The cumulative hourly SO2 concentrations at the identified ASRs were
converted into 10-minute SO2 concentrations for comparison with the
respective AQO criterion. According to the EPD’s “Guidelines on the
Estimation of 10-minute Average SO2 Concentration for Air Quality Assessment in
Hong Kong”, it is recommended that the stability-dependent multiplicative
(1) For the assessment of short-term impact, the modelled PATH background 2020 results are without traffic
emissions from concerned roads in the AoI. The PATH background results include other key air emission
sources in the vicinity of the Project as detailed in Table 4.21. Stack emissions from CPA, CPB and BPPS have
been included in the PATH. The PATH background results also include emissions from the Hong Kong
International Airport, Integrated Waste Management Facility (IWMF), and marine emissions from River Trade
Terminal.
(2) For the assessment of long-term impact, the modelled PATH background 2020 results are without stack emissions
from CPA, CPB, BPPS and traffic emissions from concerned roads in the AoI. The PATH background results
include other key air emission sources in the vicinity of the Project as detailed in Table 4.21. The PATH
background results also include emissions from the Hong Kong International Airport, Integrated Waste
Management Facility (IWMF), and marine emissions from River Trade Terminal.
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factors from Duffee et al., 1991(1) be used. The conversion factors adopted in
this assessment for the different stability classes are shown in Table 4.24.
Table 4.24 Conversion Factors from 1-hour to 10-minutes Mean Concentrations
Pasquill Stability Class Conversion Factor (1-hour to 10-minute)
A 2.45
B 2.45
C 1.82
D 1.43
E 1.35
F 1.35
Note:
(a) Reference to the EPD’s “Guidelines on the Estimation of 10-minute Average SO2 Concentration
for Air Quality Assessment in Hong Kong”
RSP (PM2.5) data are not available in the hourly PATH background
concentration results provided by the EPD. According to the EPD’s
“Guidelines on the Estimation of PM2.5 for Air Quality Assessment in Hong Kong”,
FSP (PM2.5) hourly background data can be obtained by multiplying the PATH
hourly RSP (PM10) background with a weight fraction. Table 4.25 presents the
EPD recommended FSP (PM2.5) to RSP (PM10) ratios which are adopted in this
assessment.
Table 4.25 FSP to RSP Ratios as recommended by the EPD
Annual 24-hour
FSP (PM2.5)/FSP (PM10) ratio 0.71 0.75
Note:
(a) Reference to EPD’s “Guidelines on the Estimation of PM2.5 for Air Quality Assessment in Hong
Kong”.
In cases where the predicted cumulative air quality impact at the ASRs
exceeds the AQO short-term criteria, percentage contribution from different
emission sources (i.e. additional CCGT units, existing BPPS, CPPS and road
traffic) were identified to understand the key contributor to the cumulative air
quality impact at the ASRs.
For long-term impact, a comparison of the cumulative impact between the
“With Project” and “Without Project” scenarios was made to demonstrate and
quantify the potential reduction of air pollutant concentrations at the ASRs
during normal operation of the additional CCGT unit(s). For the “With
Project” scenario, different operation scenarios to consider displacing existing
power generation from BPPS and/or CPPS by additional CCGT capacity were
also considered to show the potential improvement of the air quality with the
implementation of the Project.
(1) Richard A. Duffee, Martha A. O'Brien and Ned Ostojic (1991) Odor Modeling - Why and How. Page 295, Recent
Developments and Current Practices in Odor Regulations, Controls and Technology. Air & Waste Management
Association, 1991.
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4.7 EVALUATION OF IMPACTS (CONSTRUCTION PHASE)
4.7.1 Overview
During the construction phase, no extensive excavation or site formation will
be required as the land has been formed. Site clearance, foundation works
and building works would be the major construction works for the Project.
In view of the nature of construction works and large separation distance from
the nearest ASR, limited fugitive dust impacts would be expected. In
addition, as no ASR has been identified within 500m area from the Project Site
boundary, a quantitative assessment of the construction air quality impact
arising from the Project is considered not necessary. The construction air
quality impact has been addressed qualitatively in this section.
4.7.2 Site Clearance Activities
The area reserved for the construction of the proposed additional CCGT units
is currently occupied for the storage of materials. The structures found in the
area include a single storey warehouse (constructed of steel portal frame with
proprietary cladding enclosure) and the surrounding chain link fence with
shallow concrete footing. These structures will be demolished or removed
from the area. It is estimated that approximately 4,080 m3 of construction
and demolition (C&D) materials will be generated from site clearance, of
which approximately 2,600 m3 will be disposed of at the Tuen Mun Area 38
Fill Bank as public fill via Lung Kwu Tan Road and Lung Mun Road, while
650 m3 will be disposed of at WENT Landfill as construction waste via Nim
Wan Road. The remaining will be primarily scrap metals which will be sent
to recyclers for recycling.
4.7.3 Construction of Additional CCGT Units and its Cooling Water System
It is estimated that the quantities of excavated materials to be generated from
the construction of CCGT No.1 and its cooling water system will be
approximately 87,060 m3 between Q3 of 2016 to Q2 of 2018. The excavated
material comprises top soil, artificial hard materials (broken concrete and
asphalt), general fill and rock fill, of which approximately 78,170 m3 will
require off-site disposal, while the remaining 8,890 m3 will be reused on-site as
fill materials for general filling.
It is estimated that the quantities of excavated materials (exclude marine
sediment) to be generated from the construction of CCGT No.2 and its cooling
water system is approximately 97,170 m3. The excavated materials comprise
top soil, artificial hard material (broken concrete and asphalt), general fill, rock
fill and armour rock, of which 85,160 m3 will require off-site disposal, while
the remaining 12,010 m3 will be reused on-site as fill materials for general
filling.
It is anticipated that minor marine dredging works close to the existing
cooling water system are required if a second CCGT unit is installed. The
estimated quantities of dredged marine sediments to be generated from the
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construction of seawater intake and outfall for additional CCGT Unit No.2 are
approximately 40,000 m3, which requires off-site disposal.
4.7.4 Impact Assessment
All construction works associated with the construction of additional CCGT
units will be carried out within the existing BPPS boundary. The nearest
identified ASR is located more than 1 km away from the Project Site
boundary. Due to large separation distance between the worksite and the
nearest ASR, adverse dust impact arising from the construction activities of
the Project is not anticipated.
The Project construction site is small, with relative small quantities of C&D
materials and excavated materials generated from site clearance and the
construction of the additional CCGT units, respectively. It is anticipated that
the construction of the Project would be implemented in stages for CCGT No.1
and CCGT No.2. Tentatively, construction of CCGT No.1 is expected to
commence from Q3 of 2016 to Q2 of 2018, while the construction of CCGT
No.2 is expected to commence beyond 2019, after the commercial operation of
CCGT No.1 by the end of 2019. As the construction of CCGT No.1 and
CCGT No.2 will be carried out in two phases, the potential dust impact arising
from the construction of the Project would be further minimised. Due to the
generation of small quantities of C&D materials and excavated materials that
require off-site disposal, the number of additional truck trips generated per
day will be limited (about 23 truck trips per day). Furthermore, major
equipment for the Project will be transported to the Project site by barges, as
far as practicable, in order to minimise the number of additional truck trips on
the roads due to the construction of the Project. The potential air quality
impact due to vehicular emissions from additional trucks during the
construction phase of the Project is minimal.
With the implementation of dust control measures stipulated under the Air
Pollution Control (Construction Dust) Regulation and those recommended in
Section 4.10.1, together with proper site management and good housekeeping,
no adverse fugitive dust emission is expected from the site clearance and
construction works. Also, due to the high moisture of the dredged marine
sediments, no fugitive dust emission is expected.
4.8 EVALUATION OF IMPACTS (OPERATION PHASE)
4.8.1 Assessment of AoI
Impact from Project Contribution Only
The predicted 19th highest hourly and annual averaged NO2 concentrations at
the relevant heights of the identified ASRs during the normal operation of the
one or two additional CCGT units (440MW or 600MW per unit) at stack
heights of 80m and 100m are presented in Annex 4E. The highest percentage
of Project contribution to the hourly and annual NO2 criteria stipulated in the
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AQOs among the ASRs for scenarios of one or two additional CCGT units is
summarised in Table 4.26 and Table 4.27, respectively.
Table 4.26 Maximum Hourly Averaged and Annual Averaged NO2 Concentrations and
Highest Percentage of Project Contribution to Hourly and Annual NO 2 AQOs
for Scenario of One Additional CCGT Unit
CCGT
Operation
Stack
Height
19th Highest
Hourly NO2 (g
m-3) Contribution
from Project
Emissions (a) (b)
Percentage of
Project
Contribution to
Hourly NO2
AQO (c)
Annual NO2
(g m-3)
Contribution
from Project
Emissions (b)
Percentage of
Project
Contribution to
Annual NO2
AQO (c)
1 x 440MW
CCGT unit
80m 1.45 0.72% 0.017 0.04%
1 x 600MW
CCGT unit
80m 1.73 0.87% 0.017 0.04%
1 x 440MW
CCGT unit
100m 1.25 0.62% 0.014 0.04%
1 x 600MW
CCGT unit
100m 1.51 0.75% 0.015 0.04%
Notes:
(a) 18 exceedances allowed for hourly NO2 criterion.
(b) The NO2 contribution presented is the maximum among all ASRs.
(c) The percentage presented is the maximum among all ASRs.
Table 4.27 Maximum 19th Highest Hourly Averaged and Annual Averaged NO2
Concentrations and Highest Percentage of Project Contribution to Hourly and
Annual NO2 AQOs for Scenario of Two Additional CCGT Units
CCGT
Operation
Stack
Height
19th Highest
Hourly NO2 (g
m-3) Contribution
from Project
Emissions (a)(b)
Percentage of
Project
Contribution to
Hourly NO2
AQO (c)
Annual NO2
(g m-3)
Contribution
from Project
Emissions (b)
Percentage of
Project
Contribution to
Annual NO2
AQO (c)
2 x 440MW
CCGT units
80m 2.86 1.43% 0.033 0.08%
2 x 600MW
CCGT units
80m 3.44 1.72% 0.034 0.09%
2 x 440MW
CCGT units
100m 2.47 1.24% 0.029 0.07%
2 x 600MW
CCGT units
100m 2.98 1.49% 0.030 0.08%
Notes:
(a) 18 exceedances allowed for hourly NO2 criterion.
(b) The NO2 contribution presented is the maximum among all ASRs.
(c) The percentage presented is the maximum among all ASRs.
At stack heights of 80m and 100m, the predicted 19th highest hourly and
annual averaged NO2 concentrations at the relevant heights of all the
identified ASRs during the normal operation of one or two additional CCGT
units are lower than the respective SIL which is 3.5% and 1% of the hourly and
annual NO2 criteria stipulated in the AQOs, respectively.
The top three highest hourly averaged NO2 concentrations at the relevant
heights of the identified ASRs are also provided in Annex 4E. The Project
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contribution (1st, 2nd and 3rd highest hourly NO2 concentrations) to the hourly
NO2 criterion among the ASRs for scenarios of one or two additional CCGT
units is presented in Table 4.28 and Table 4.29, respectively. It can be seen that
the maximum Project contribution in terms of top three highest hourly
averaged NO2 concentrations is also low, which is less than 3% and 5% of the
relevant NO2 criterion for scenario of one or two additional CCGT units,
respectively. It is considered, therefore, that the impact arising from the
operation of the two proposed additional CCGT units is likely to result in
insignificant impacts within the Assessment Area.
Table 4.28 Top Three Highest Hourly Averaged NO2 Concentrations and Highest
Percentage of Project Contribution to Hourly NO2 AQO for Scenario of One
Additional CCGT Unit
CCGT Operation Stack Height Hourly NO2 (g m-3)
Contribution from
Project Emissions (a)
Percentage of Project
Contribution to
Hourly NO2 AQO (b)
1st Highest
1 x 440MW CCGT unit 80m 5.35 2.67%
1 x 600MW CCGT unit 80m 5.42 2.71%
1 x 440MW CCGT unit 100m 4.00 2.00%
1 x 600MW CCGT unit 100m 4.73 2.34%
2nd Highest
1 x 440MW CCGT unit 80m 4.17 2.08%
1 x 600MW CCGT unit 80m 5.01 2.50%
1 x 440MW CCGT unit 100m 3.63 1.81%
1 x 600MW CCGT unit 100m 4.34 2.17%
3rd Highest
1 x 440MW CCGT unit 80m 3.67 1.84%
1 x 600MW CCGT unit 80m 4.25 2.13%
1 x 440MW CCGT unit 100m 3.17 1.58%
1 x 600MW CCGT unit 100m 3.69 1.85%
Notes:
(a) The NO2 contribution presented is the maximum among all ASRs.
(b) The percentage presented is the maximum among all ASRs.
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Table 4.29 Top Three Highest Hourly Averaged NO2 Concentrations and Highest
Percentage of Project Contribution to Hourly NO2 AQO for Scenario of Two
Additional CCGT Units
CCGT Operation Stack Height Hourly NO2 (g m-3)
Contribution from
Project Emissions (a)
Percentage of Project
Contribution to
Hourly NO2 AQO (b)
1st Highest
2 x 440MW CCGT unit 80m 9.72 4.86%
2 x 600MW CCGT unit 80m 9.99 4.99%
2 x 440MW CCGT unit 100m 7.22 3.61%
2 x 600MW CCGT unit 100m 8.56 4.28%
2nd Highest
2 x 440MW CCGT unit 80m 7.72 3.86%
2 x 600MW CCGT unit 80m 9.30 4.65%
2 x 440MW CCGT unit 100m 6.76 3.38%
2 x 600MW CCGT unit 100m 8.11 4.05%
3rd Highest
2 x 440MW CCGT unit 80m 7.06 3.53%
2 x 600MW CCGT unit 80m 8.30 4.15%
2 x 440MW CCGT unit 100m 6.14 3.07%
2 x 600MW CCGT unit 100m 7.14 3.57%
Notes:
(a) The NO2 contribution presented is the maximum among all ASRs.
(b) The percentage presented is the maximum among all ASRs.
Review of Monitoring Data recorded at AQMSs Operated by CLP and EPD within
the Assessment Area in the Recent Past 5 Years (i.e. 2010 – 2014)
A summary of the recorded 19th highest hourly averaged NO2 concentrations
at the AQMSs from 2010 to 2014 is also shown in Table 4.30. A summary of
number of exceedances of hourly NO2 criterion and annual averaged NO2
concentrations recorded at the five CLP’s AQMSs and three EPD’s AQMSs
from 2010 to 2014 are presented in Table 4.31 and Table 4.32, respectively.
Table 4.30 Summary of Recorded 19th Highest Hourly Averaged NO2 Concentrations at
the Identified AQMSs from 2010 to 2014
AQMS Recorded 19th Highest Hourly Averaged NO2
Concentration (µg m-3)
Prevailing
Hourly NO2
AQO (µg m-3)
2010 2011 2012 2013 2014
CLP Butterfly Estate 152 175 147 204 (a) 169 200
Lau Fau Shan 164 171 136 155 147 200
Lung Kwu Tan 149 153 128 149 149 200
Tin Shui Wai 172 150 125 180 154 200
San Hui/Tuen Mun
Clinic 206 (a) 229 (a) 192 228 (a) 195 200
EPD Tung Chung 203 (a) 184 166 177 198 200
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AQMS Recorded 19th Highest Hourly Averaged NO2
Concentration (µg m-3)
Prevailing
Hourly NO2
AQO (µg m-3)
2010 2011 2012 2013 2014
Yuen Long 194 188 147 183 165 200
Tuen Mun(b) - - - - 184 200
Notes:
(a) Exceedance of 1-hour NO2 criterion.
(b) Tuen Mun AQMS in operation since 2014.
Table 4.31 Summary of Recorded Number of Exceedances of Hourly NO2 Criterion at the
Identified AQMSs from 2010 to 2014
AQMS Number of Exceedances of Hourly NO2
Criterion
Allowable No.
of Exceedances
of Hourly NO2
AQO 2010 2011 2012 2013 2014
CLP Butterfly Estate 1 5 2 22 (a) 1 18
Lau Fau Shan 7 0 2 3 0 18
Lung Kwu Tan 2 7 0 3 0 18
Tin Shui Wai 7 0 0 7 0 18
San Hui/Tuen Mun
Clinic
27(a) 44 (a) 12 40 (a) 14 18
EPD Tung Chung 20(a) 5 4 2 14 18
Yuen Long 13 8 0 7 4 18
Tuen Mun - - - - 10 18
Note:
(a) No. of exceedances is more than the allowable no. of exceedances of hourly NO2 AQO.
Table 4.32 Summary of Recorded Annual Averaged NO2 Concentrations at the Identified
AQMSs from 2010 to 2014
AQMS Recorded Annual Averaged NO2
Concentrations (µg m-3)
Prevailing
Annual NO2
AQO (µg m-3) 2010 2011 2012 2013 2014
CLP Butterfly Estate 38 41 (a) 45 (a) 47 (a) 42 (a) 40
Lau Fau Shan 29 36 30 30 31 40
Lung Kwu Tan 26 31 26 28 27 40
Tin Shui Wai 40 39 32 45 (a) 34 40
San Hui/Tuen Mun
Clinic
68 (a) 72 (a) 65(a) 63 (a) 55 (a) 40
EPD Tung Chung 44 (a) 51 (a) 43(a) 49 (a) 45 (a) 40
Yuen Long 54 (a) 54 (a) 49(a) 54 (a) 52 (a) 40
Tuen Mun(b) - - - - 53 (a) 40
Notes:
(a) Exceedance of annual NO2 criterion.
(b) Tuen Mun AQMS in operation since 2014. Highlight ed data denotes exceedance of
prevailing annual NO2 AQO.
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The number of exceedances of hourly NO2 concentrations exceeded the
allowable number of exceedances of prevailing hourly NO2 AQO at CLP
Butterfly Estate AQMS in 2013 while the number of exceedances of hourly
NO2 concentrations exceeded the allowable number of exceedance of
prevailing hourly NO2 AQO at San Hui/Tuen Mun Clinic in 2010, 2011 and
2013.
The annual averaged NO2 concentrations recorded at all AQMSs except at Lau
Fau Shan and Lung Kwu Tan in 2010 - 2014 exceeded the prevailing annual
NO2 AQO.
Summary and Identification of AoI for Cumulative Impact Assessment
Assessment results showed that the air quality impact arising from the
operation of the one or two additional CCGT units (440MW or 600MW per
unit) is insignificant and the identification of AoI would be determined by the
existing air quality in terms of the monitored NO2 concentrations within the
Assessment Area. Exceedances of the hourly or annual NO2 were observed
at the AQMSs located in Butterfly Estate, Tuen Mun Town Centre, Yuen Long,
Tin Shui Wai and Tung Chung. A 500m area from the location of each of
these AQMSs has been identified as the AoI for cumulative impact
assessment. As described in Section 4.6.1, the ASRs within the AoIs to be
included in the cumulative impact assessment have been further selected
based on the principle that they are located near the major roads or near the
AQMS, such that the cumulative air quality impact at these ASRs are
conservative and are reasonable representatives of that particular AoI. The
selected ASRs within the AoIs for cumulative impact assessment are
presented in Table 4.33. The five identified AoIs and the selected ASRs
within the AoIs for cumulative impact assessment are shown in Figure 4.3 to
Figure 4.7.
Table 4.33 Selected Representative ASRs for Cumulative Air Quality Impact Assessment
Area ASR Description Use Approximate
Distance from
Site Boundary
(km)
Approximate
Maximum
Height (m
above ground)
Butterfly
Estate AoI
TM7 Butterfly Estate Residential 6.8 100
TM7a Melody Garden Residential 6.5 100
TM7b Siu Shan Court Residential 6.5 60
Tin Shui Wai
AoI
TSW4 Tin Shui Estate Residential 10.2 120
TSW4a Tin Yan Estate Residential 10.4 120
TSW4b Tin Wah Estate Residential 10.3 80
TSW4c Tin Chung Court Residential 10.7 120
TSW7 Low-rise building on
Man Tak Road
Residential 10.0 20
Tuen Mun
AoI (a)
TM1a Lakeshore Building Residential 7.1 60
TM1b Parkview Court Residential 6.9 100
TM2 Kam Hing Building Residential 6.8 100
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Area ASR Description Use Approximate
Distance from
Site Boundary
(km)
Approximate
Maximum
Height (m
above ground)
TM3 Tuen Mun Town Plaza Residential 7.1 120
TM4 On Ting Estate Residential 7.3 120
TM10 Chi Lok Fa Yuen Residential 7.6 60
Yuen Long
AoI
YL5 Shui Pin Tsuen Recreational 12.0 10
YL5b Man Cheong Building Commercial 12.4 20
Tung Chung
AoI
TC2a Seaview Crescent Residential 13.5 120
TC2b Coastal Skyline La
Rossa
Residential 13.7 120
TC2c Yu Tung Court Residential 13.9 100
TC2d Tung Chung Crescent Residential 13.8 120
TC5 Ling Liang Church E
Wun Secondary School
Educational
Institution
13.8 40
TC6 Ching Chung Hau Po
Woon Primary School
Educational
Institution
13.9 40
Note:
(a) Tuen Mun AoI includes a 500m area from CLP’s San Hui/Tuen Mun Clinic AQMS a nd
EPD’s Tuen Mun AQMS.
Assessment results showed that the NO2 contribution at the ASRs due to
operation of one or two additional CCGT units was higher with stack height at
80m above ground in comparison to 100m. A stack height of 80m above
ground for the additional CCGT unit(s) was therefore adopted for the
cumulative impact assessment as a worst case approach.
4.8.2 Cumulative Air Quality Impact
The cumulative impact to the surrounding land use has been considered
against the short-term criteria (10-minute, 1-hour and 24 hour) using
reasonable worst-case emission rates and against the long-term criteria
(annual) using anticipated annual emissions including a diurnal profile for the
emissions of most concern (NO2, RSP (PM10), FSP (PM2.5) and SO2).
Short-term Impact
Eight scenarios have been assessed at each of the identified ASRs for the
operation of one or two additional CCGT units, including:
1 x 440MW normal operations using natural gas;
1 x 600MW normal operations using natural gas;
1 x 440MW back-up using diesel fuel;
1 x 600MW back-up using diesel fuel;
2 x 440MW normal operations using natural gas;
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2 x 600MW normal operations using natural gas;
2 x 440MW back-up using diesel fuel;
2 x 600MW back-up using diesel fuel;
For all the scenarios which take into account the operation of one or two
additional CCGT units, the results show that:
Cumulative total 1-hour average NO2 predictions at all locations are
below the criterion of 200 µg m-3;
Cumulative total 24-hour average RSP (PM10) predictions at all locations
are below the criterion of 100 µg m-3;
Cumulative total 24-hour average FSP (PM2.5) predictions at all locations
are below the criterion of 75 µg m-3;
Cumulative total 10-minute average SO2 predictions at all locations are
below the criterion of 500 µg m-3; and
Cumulative total 24-hour average SO2 predictions at all locations are
below the criterion of 125 µg m-3.
Full results, including a breakdown of contribution at each ASR and height for
each of the scenarios for 1-hour NO2, 24-hour RSP (PM10), 24-hour FSP (PM2.5),
10-minute SO2 and 24-hour SO2 are shown in Annex 4F.
Table 4.34 to Table 4.38 provide a summary of the maximum predicted total
concentrations at each representative ASR for the considered pollutants and
averaging periods during the operation of one additional CCGT unit, while
the results for the operation of two additional CCGT units are presented in
Table 4.39 to Table 4.43. As NO2 is considered the potential key air pollutant
associated with the operation of the CCGT units, contours of the cumulative
19th highest 1-hour average NO2 concentrations for the normal operation
scenario (i.e. one additional 600MW CCGT unit; two additional 600MW CCGT
units) in different AoIs are presented in Figure 4.8 to Figure 4.17. Contours of
the cumulative 19th highest 1-hour average NO2 concentrations for the back-up
operation scenario (i.e. one additional 600MW CCGT unit; two additional
600MW CCGT units) in different AoIs are presented in Figure 4.18 to Figure
4.27.
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Table 4.34 Predicted Cumulative 19th Highest 1-Hour NO2 Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of One
Additional CCGT Unit
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 148.6 1.5 148.6 1.5 148.6 1.5 148.6 1.5
Melody Garden 146.6 1.5 146.6 1.5 146.6 1.5 146.6 1.5
Siu Shan Court 148.5 1.5 148.5 1.5 148.5 1.5 148.5 1.5
Tin Shui
Wai
Tin Shui Estate 140.2 1.5 140.2 1.5 140.2 1.5 140.2 1.5
Tin Yan Estate 145.9 1.5 146.2 1.5 151.4 1.5 151.4 1.5
Tin Wah Estate 145.5 1.5 145.5 1.5 152.1 1.5 152.1 1.5
Tin Chung Court 145.1 1.5 145.1 1.5 152.1 1.5 152.1 1.5
Low-rise building on Man
Tak Road 152.1 1.5 152.1 1.5 152.1 1.5 152.1 1.5
Tuen
Mun
Lakeshore Building 156.5 1.5 156.5 1.5 159.6 1.5 159.6 1.5
Parkview Court 157.5 1.5 157.5 1.5 157.5 1.5 159.9 1.5
Kam Hing Building 152.3 1.5 152.3 1.5 152.3 1.5 152.3 1.5
Tuen Mun Town Plaza 160.7 1.5 160.7 1.5 160.7 1.5 162.9 1.5
On Ting Estate 143.3 1.5 143.3 1.5 143.3 1.5 143.3 1.5
Chi Lok Fa Yuen 146.4 1.5 146.4 1.5 146.4 1.5 146.8 1.5
Yuen
Long
Shui Pin Tsuen 161.0 1.5 161.0 1.5 161.0 1.5 161.0 1.5
Man Cheong Building 163.4 1.5 163.4 1.5 163.4 1.5 164.6 1.5
Tung
Chung
Seaview Cresent 168.8 1.5 168.8 1.5 169.2 1.5 169.2 1.5
Coastal Skyline La Rossa 168.8 1.5 168.8 1.5 169.1 1.5 169.1 1.5
Ling Liang Church E Wun
Secondary School 172.2 1.5 172.2 1.5 172.2 1.5 172.2 1.5
Yu Tung Court 130.4 1.5 130.4 1.5 130.4 1.5 130.4 1.5
Tung Chung Crescent 131.2 1.5 131.2 1.5 131.2 1.5 131.2 1.5
Ching Chung Hau Po Woon
Primary School 133.0 1.5 133.0 1.5 133.0 1.5 133.0 1.5
Criterion 200 - 200 - 200 - 200 -
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Table 4.35 Predicted Cumulative 10th Highest 24-Hour RSP (PM10) Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of
One Additional CCGT Unit
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 83.0 1.5 83.0 1.5 83.0 1.5 83.0 1.5
Melody Garden 82.7 1.5 82.7 1.5 82.7 1.5 82.7 1.5
Siu Shan Court 83.0 1.5 83.0 1.5 83.0 1.5 83.0 1.5
Tin Shui
Wai
Tin Shui Estate 83.4 1.5 83.4 1.5 83.4 1.5 83.4 1.5
Tin Yan Estate 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Tin Wah Estate 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Tin Chung Court 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Low-rise building on Man
Tak Road 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Tuen
Mun
Lakeshore Building 84.4 1.5 84.4 1.5 84.4 1.5 84.4 1.5
Parkview Court 87.2 1.5 87.2 1.5 87.2 1.5 87.2 1.5
Kam Hing Building 86.9 1.5 86.9 1.5 86.9 1.5 86.9 1.5
Tuen Mun Town Plaza 86.7 1.5 86.7 1.5 86.9 1.5 87.0 1.5
On Ting Estate 81.9 1.5 81.9 1.5 81.9 1.5 81.9 1.5
Chi Lok Fa Yuen 81.8 1.5 81.8 1.5 81.8 1.5 81.8 1.5
Yuen
Long
Shui Pin Tsuen 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Man Cheong Building 83.8 1.5 83.8 1.5 83.8 1.5 83.8 1.5
Tung
Chung
Seaview Crescent 79.0 1.5 79.0 1.5 79.0 1.5 79.0 1.5
Coastal Skyline La Rossa 79.0 1.5 79.0 1.5 79.0 1.5 79.0 1.5
Ling Liang Church E Wun
Secondary School 79.3 1.5 79.3 1.5 79.3 1.5 79.3 1.5
Yu Tung Court 78.3 1.5 78.3 1.5 78.3 1.5 78.3 1.5
Tung Chung Crescent 78.2 1.5 78.2 1.5 78.2 1.5 78.2 1.5
Ching Chung Hau Po Woon
Primary School 78.5 1.5 78.5 1.5 78.5 1.5 78.5 1.5
Criterion 100 - 100 - 100 - 100 -
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Table 4.36 Predicted Cumulative 10th Highest 24-Hour FSP (PM2.5) Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of
One Additional CCGT Unit
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 62.3 1.5 62.3 1.5 62.3 1.5 62.3 1.5
Melody Garden 62.1 1.5 62.1 1.5 62.1 1.5 62.1 1.5
Siu Shan Court 62.3 1.5 62.3 1.5 62.3 1.5 62.3 1.5
Tin Shui
Wai
Tin Shui Estate 62.6 1.5 62.6 1.5 62.6 1.5 62.6 1.5
Tin Yan Estate 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Tin Wah Estate 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Tin Chung Court 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Low-rise building on Man
Tak Road 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Tuen
Mun
Lakeshore Building 64.3 1.5 64.4 1.5 64.5 1.5 64.6 1.5
Parkview Court 65.3 1.5 65.3 1.5 65.3 1.5 65.3 1.5
Kam Hing Building 64.9 1.5 64.9 1.5 64.9 1.5 65.0 1.5
Tuen Mun Town Plaza 64.2 1.5 64.2 1.5 64.2 1.5 64.2 1.5
On Ting Estate 61.5 1.5 61.5 1.5 61.5 1.5 61.5 1.5
Chi Lok Fa Yuen 61.4 1.5 61.4 1.5 61.4 1.5 61.4 1.5
Yuen
Long
Shui Pin Tsuen 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Man Cheong Building 62.9 1.5 62.9 1.5 62.9 1.5 62.9 1.5
Tung
Chung
Seaview Crescent 59.3 1.5 59.3 1.5 59.3 1.5 59.3 1.5
Coastal Skyline La Rossa 59.4 1.5 59.4 1.5 59.4 1.5 59.4 1.5
Ling Liang Church E Wun
Secondary School 59.6 1.5 59.6 1.5 59.6 1.5 59.6 1.5
Yu Tung Court 58.9 1.5 58.9 1.5 58.9 1.5 58.9 1.5
Tung Chung Crescent 58.8 1.5 58.8 1.5 58.8 1.5 58.8 1.5
Ching Chung Hau Po Woon
Primary School 59.0 1.5 59.0 1.5 59.0 1.5 59.0 1.5
Criterion 75 - 75 - 75 - 75 -
ENVIRONMENTAL RESOURCES MANAGEMENT CASTLE PEAK POWER COMPANY LIMITED
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Table 4.37 Predicted Cumulative 4th Highest 10-Minute SO2 Concentrations (µg m-3) (a) at the Identified ASRs within the AoIs during the Operation of One
Additional CCGT Unit
AoI Receptor 440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum Modelled
Height of maximum
Maximum Modelled
Height of maximum
Maximum Modelled
Height of maximum
Maximum Modelled
Height of maximum
Butterfly Estate
Butterfly Estate 157.5 100 157.5 100 157.5 100 157.5 100
Melody Garden 183.8 100 183.8 100 183.8 100 183.8 100
Siu Shan Court 157.5 60 157.5 60 157.5 60 157.5 60
Tin Shui Wai
Tin Shui Estate 225.6 120 225.6 120 225.6 120 225.6 120
Tin Yan Estate 242.6 120 242.6 120 242.6 120 242.6 120
Tin Wah Estate 242.6 80 242.6 80 242.6 80 242.6 80
Tin Chung Court 242.6 120 242.6 120 242.6 120 242.6 120
Low-rise building on Man Tak Road
270.5 20 270.5 20 270.5 20 270.5 20
Tuen Mun
Lakeshore Building 200.9 60 200.9 60 200.9 60 200.9 60
Parkview Court 201.4 100 201.4 100 201.4 100 201.4 100
Kam Hing Building 201.4 100 201.4 100 201.4 100 201.4 100
Tuen Mun Town Plaza 173.2 120 173.2 120 173.2 120 173.2 120
On Ting Estate 179.8 120 179.8 120 179.8 120 179.8 120
Chi Lok Fa Yuen 179.8 60 179.8 60 179.8 60 179.8 60
Yuen Long
Shui Pin Tsuen 261.9 10 261.9 10 261.9 10 261.9 10
Man Cheong Building 261.9 20 261.9 20 261.9 20 261.9 20
Tung Chung
Seaview Cresent 181.5 120 181.5 120 181.5 120 181.5 120
Coastal Skyline La Rossa 181.5 120 181.5 120 181.5 120 181.5 120
Ling Liang Church E Wun Secondary School
181.5 40 181.5 40 181.5 40 181.5 40
Yu Tung Court 165.9 100 165.9 100 165.9 100 165.9 100
Tung Chung Crescent 165.9 120 165.9 120 165.9 120 165.9 120
Ching Chung Hau Po Woon Primary School 165.9 40 165.9 40 165.9 40 165.9 40
Criterion 500 - 500 - 500 - 500 -
Note:
(a) For conservative assessment, the predicted cumulative 4 th highest 10-minute SO2 concentrations presented were calculated from the predicted cumulative maximum
hourly SO2 concentrations based on the stability-dependent multiplicative factors. According to this conversion method, the predicted cumulative 4 th highest 10-minute
SO2 concentration is equal to the predicted cumulative maximum 10-minute SO2 concentration.
ENVIRONMENTAL RESOURCES MANAGEMENT CASTLE PEAK POWER COMPANY LIMITED
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Table 4.38 Predicted Cumulative 4th Highest 24-Hour SO2 Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of One
Additional CCGT Unit
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 34.2 100 34.2 100 34.2 100 34.2 100
Melody Garden 34.8 100 34.8 100 34.8 100 34.8 100
Siu Shan Court 34.2 60 34.2 60 34.2 60 34.2 60
Tin Shui
Wai
Tin Shui Estate 33.2 120 33.2 120 33.2 120 33.2 120
Tin Yan Estate 34.2 120 34.2 120 34.2 120 34.2 120
Tin Wah Estate 34.2 80 34.2 80 34.2 80 34.2 80
Tin Chung Court 34.2 120 34.2 120 34.2 120 34.2 120
Low-rise building on Man
Tak Road 37.5 20 37.5 20 37.5 20 37.5 20
Tuen
Mun
Lakeshore Building 28.1 60 28.1 60 28.1 60 28.1 60
Parkview Court 31.7 100 31.7 100 31.7 100 31.7 100
Kam Hing Building 31.7 100 31.7 100 31.7 120 31.7 100
Tuen Mun Town Plaza 32.5 120 32.5 120 32.4 120 32.5 120
On Ting Estate 29.6 120 29.6 120 29.6 120 29.6 120
Chi Lok Fa Yuen 29.6 60 29.6 60 29.6 60 29.6 60
Yuen
Long
Shui Pin Tsuen 28.5 10 28.6 10 28.4 10 28.4 10
Man Cheong Building 28.5 20 28.6 20 28.4 20 28.4 20
Tung
Chung
Seaview Cresent 39.2 120 39.2 120 39.2 120 39.2 120
Coastal Skyline La Rossa 39.2 120 39.2 120 39.2 120 39.2 120
Ling Liang Church E Wun
Secondary School 39.2 40 39.2 40 39.2 40 39.2 40
Yu Tung Court 36.8 100 36.8 100 36.8 100 36.8 100
Tung Chung Crescent 36.8 120 36.8 120 36.8 120 36.8 120
Ching Chung Hau Po Woon
Primary School 36.8 40 36.8 40 36.8 40 36.8 40
Criterion 125 - 125 - 125 - 125 -
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Table 4.39 Predicted Cumulative 19th Highest 1-Hour NO2 Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of Two
Additional CCGT Units
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 148.6 1.5 148.6 1.5 148.6 1.5 148.6 1.5
Melody Garden 146.6 1.5 146.6 1.5 146.6 1.5 146.6 1.5
Siu Shan Court 148.5 1.5 148.5 1.5 148.5 1.5 148.5 1.5
Tin Shui
Wai
Tin Shui Estate 140.2 1.5 140.2 1.5 140.5 1.5 140.5 1.5
Tin Yan Estate 147.9 1.5 148.6 1.5 153.3 1.5 156.4 1.5
Tin Wah Estate 145.5 1.5 145.5 1.5 154.2 1.5 154.6 1.5
Tin Chung Court 145.1 1.5 145.1 1.5 154.8 1.5 154.8 1.5
Low-rise building on Man
Tak Road 152.1 1.5 152.1 1.5 152.1 1.5 152.1 1.5
Tuen
Mun
Lakeshore Building 156.5 1.5 156.5 1.5 160.3 1.5 160.4 1.5
Parkview Court 157.5 1.5 157.5 1.5 159.9 1.5 159.9 1.5
Kam Hing Building 152.3 1.5 152.3 1.5 153.2 1.5 153.2 1.5
Tuen Mun Town Plaza 160.7 1.5 160.7 1.5 163.9 1.5 163.9 1.5
On Ting Estate 143.3 1.5 143.3 1.5 146.2 1.5 146.2 1.5
Chi Lok Fa Yuen 146.4 1.5 146.4 1.5 154.4 1.5 154.4 1.5
Yuen
Long
Shui Pin Tsuen 161.0 1.5 161.0 1.5 161.3 1.5 161.3 1.5
Man Cheong Building 163.4 1.5 163.4 1.5 164.6 1.5 164.9 1.5
Tung
Chung
Seaview Cresent 168.9 1.5 168.9 1.5 169.3 1.5 169.4 1.5
Coastal Skyline La Rossa 168.8 1.5 168.8 1.5 169.2 1.5 169.2 1.5
Ling Liang Church E Wun
Secondary School 172.2 1.5 172.2 1.5 172.2 1.5 172.2 1.5
Yu Tung Court 130.4 1.5 130.4 1.5 130.4 1.5 130.4 1.5
Tung Chung Crescent 131.2 1.5 131.2 1.5 131.2 1.5 131.2 1.5
Ching Chung Hau Po Woon
Primary School 133.0 1.5 133.0 1.5 133.0 1.5 133.0 1.5
Criterion 200 - 200 - 200 - 200 -
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Table 4.40 Predicted Cumulative 10th Highest 24-Hour RSP (PM10) Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of
Two Additional CCGT Units
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 83.0 1.5 83.0 1.5 83.0 1.5 83.0 1.5
Melody Garden 82.7 1.5 82.7 1.5 82.8 1.5 82.9 1.5
Siu Shan Court 83.0 1.5 83.0 1.5 83.0 1.5 83.0 1.5
Tin Shui
Wai
Tin Shui Estate 83.4 1.5 83.4 1.5 83.4 1.5 83.4 1.5
Tin Yan Estate 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Tin Wah Estate 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Tin Chung Court 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Low-rise building on Man
Tak Road 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Tuen
Mun
Lakeshore Building 84.4 1.5 84.4 1.5 84.4 1.5 84.4 1.5
Parkview Court 87.2 1.5 87.2 1.5 87.2 1.5 87.3 1.5
Kam Hing Building 86.9 1.5 86.9 1.5 87.0 1.5 87.1 1.5
Tuen Mun Town Plaza 86.9 1.5 87.0 1.5 87.3 1.5 87.5 1.5
On Ting Estate 81.9 1.5 81.9 1.5 81.9 1.5 81.9 1.5
Chi Lok Fa Yuen 81.8 1.5 81.8 1.5 81.8 1.5 81.8 1.5
Yuen
Long
Shui Pin Tsuen 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5
Man Cheong Building 83.8 1.5 83.8 1.5 83.8 1.5 83.8 1.5
Tung
Chung
Seaview Crescent 79.0 1.5 79.0 1.5 79.0 1.5 79.0 1.5
Coastal Skyline La Rossa 79.0 1.5 79.0 1.5 79.0 1.5 79.0 1.5
Ling Liang Church E Wun
Secondary School 79.3 1.5 79.3 1.5 79.3 1.5 79.3 1.5
Yu Tung Court 78.3 1.5 78.3 1.5 78.3 1.5 78.3 1.5
Tung Chung Crescent 78.2 1.5 78.2 1.5 78.2 1.5 78.2 1.5
Ching Chung Hau Po Woon
Primary School 78.5 1.5 78.5 1.5 78.5 1.5 78.5 1.5
Criterion 100 - 100 - 100 - 100 -
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Table 4.41 Predicted Cumulative 10th Highest 24-Hour FSP (PM2.5) Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of
Two Additional CCGT Units
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 62.3 1.5 62.3 1.5 62.3 1.5 62.3 1.5
Melody Garden 62.1 1.5 62.1 1.5 62.2 1.5 62.3 1.5
Siu Shan Court 62.3 1.5 62.3 1.5 62.3 1.5 62.3 1.5
Tin Shui
Wai
Tin Shui Estate 62.6 1.5 62.6 1.5 62.6 1.5 62.6 1.5
Tin Yan Estate 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Tin Wah Estate 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Tin Chung Court 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Low-rise building on Man
Tak Road 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Tuen
Mun
Lakeshore Building 64.5 1.5 64.5 1.5 64.7 1.5 64.7 1.5
Parkview Court 65.3 1.5 65.3 1.5 65.3 1.5 65.4 1.5
Kam Hing Building 64.9 1.5 65.0 1.5 65.1 1.5 65.2 1.5
Tuen Mun Town Plaza 64.2 1.5 64.2 1.5 64.2 1.5 64.2 1.5
On Ting Estate 61.5 1.5 61.5 1.5 61.5 1.5 61.5 1.5
Chi Lok Fa Yuen 61.4 1.5 61.4 1.5 61.4 1.5 61.4 1.5
Yuen
Long
Shui Pin Tsuen 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5
Man Cheong Building 62.9 1.5 62.9 1.5 62.9 1.5 62.9 1.5
Tung
Chung
Seaview Crescent 59.3 1.5 59.3 1.5 59.3 1.5 59.3 1.5
Coastal Skyline La Rossa 59.4 1.5 59.4 1.5 59.4 1.5 59.4 1.5
Ling Liang Church E Wun
Secondary School 59.6 1.5 59.6 1.5 59.6 1.5 59.6 1.5
Yu Tung Court 58.9 1.5 58.9 1.5 58.9 1.5 58.9 1.5
Tung Chung Crescent 58.8 1.5 58.8 1.5 58.8 1.5 58.8 1.5
Ching Chung Hau Po Woon
Primary School 59.0 1.5 59.0 1.5 59.0 1.5 59.0 1.5
Criterion 75 - 75 - 75 - 75 -
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Table 4.42 Predicted Cumulative 4th Highest 10-Minute SO2 Concentrations (µg m-3) (a) at the Identified ASRs within the AoIs during the Operation of
Two Additional CCGT Units
AoI Receptor 440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum Modelled
Height of maximum
Maximum Modelled
Height of maximum
Maximum Modelled
Height of maximum
Maximum Modelled
Height of maximum
Butterfly Estate
Butterfly Estate 157.5 100 157.5 100 157.5 100 157.5 100
Melody Garden 183.8 100 183.8 100 183.8 100 183.8 100
Siu Shan Court 157.5 60 157.5 60 157.5 60 157.5 60
Tin Shui Wai
Tin Shui Estate 225.6 120 225.6 120 225.6 120 225.6 120
Tin Yan Estate 242.6 120 242.6 120 242.6 120 242.6 120
Tin Wah Estate 242.6 80 242.6 80 242.6 80 242.6 80
Tin Chung Court 242.6 120 242.6 120 242.6 120 242.6 120
Low-rise building on Man Tak Road
270.5 20 270.5 20 270.5 20 270.5 20
Tuen Mun
Lakeshore Building 200.9 60 200.9 60 200.9 60 200.9 60
Parkview Court 201.4 100 201.4 100 201.4 100 201.4 100
Kam Hing Building 201.4 100 201.4 100 201.4 100 201.4 100
Tuen Mun Town Plaza 173.2 120 173.2 120 173.2 120 173.2 120
On Ting Estate 179.8 120 179.8 120 179.8 120 179.8 120
Chi Lok Fa Yuen 179.8 60 179.8 60 179.8 60 179.8 60
Yuen Long Shui Pin Tsuen 261.9 10 261.9 10 261.9 10 261.9 10
Man Cheong Building 261.9 20 261.9 20 261.9 20 261.9 20
Tung Chung
Seaview Cresent 181.5 120 181.5 120 181.5 120 181.5 120
Coastal Skyline La Rossa 181.5 120 181.5 120 181.5 120 181.5 120
Ling Liang Church E Wun Secondary School
181.5 40 181.5 40 181.5 40 181.5 40
Yu Tung Court 165.9 100 165.9 100 165.9 100 165.9 100
Tung Chung Crescent 165.9 120 165.9 120 165.9 120 165.9 120
Ching Chung Hau Po Woon Primary School 165.9 40 165.9 40 165.9 40 165.9 40
Criterion 500 - 500 - 500 - 500 -
Note:
(a) For conservative assessment, the predicted cumulative 4 th highest 10-minute SO2 concentrations presented were calculated from the predicted cumulative maximum
hourly SO2 concentrations based on the stability-dependent multiplicative factors. According to this conversion method, the predicted cumulative 4 th highest 10-minute
SO2 concentration is equal to the predicted cumulative maximum 10-minute SO2 concentration.
ENVIRONMENTAL RESOURCES MANAGEMENT CASTLE PEAK POWER COMPANY LIMITED
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Table 4.43 Predicted Cumulative 4th Highest 24-Hour SO2 Concentrations (µg m-3) at the Identified ASRs within the AoIs during the Operation of Two
Additional CCGT Units
AoI Receptor
440MW Normal 600MW Normal 440MW Backup 600MW Backup
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 34.2 100 34.2 100 34.2 100 34.2 100
Melody Garden 34.8 100 34.8 100 34.8 100 34.8 100
Siu Shan Court 34.2 60 34.2 60 34.2 60 34.2 60
Tin Shui
Wai
Tin Shui Estate 33.2 120 33.2 120 33.2 120 33.2 120
Tin Yan Estate 34.2 120 34.2 120 34.2 120 34.2 120
Tin Wah Estate 34.2 80 34.2 80 34.2 80 34.2 80
Tin Chung Court 34.2 120 34.2 120 34.2 120 34.2 120
Low-rise building on Man
Tak Road 37.5 20 37.5 20 37.5 20 37.5 20
Tuen
Mun
Lakeshore Building 28.1 60 28.1 60 28.1 60 28.1 60
Parkview Court 31.7 100 31.7 100 31.7 100 31.7 100
Kam Hing Building 31.7 100 31.7 100 31.7 100 31.7 100
Tuen Mun Town Plaza 32.5 120 32.5 120 32.5 120 32.5 120
On Ting Estate 29.6 120 29.6 120 29.6 120 29.6 120
Chi Lok Fa Yuen 29.6 60 29.6 60 29.6 60 29.6 60
Yuen
Long
Shui Pin Tsuen 28.7 10 28.8 10 28.5 10 28.5 10
Man Cheong Building 28.7 20 28.7 20 28.5 20 28.5 20
Tung
Chung
Seaview Cresent 39.2 120 39.2 120 39.2 120 39.2 120
Coastal Skyline La Rossa 39.2 120 39.2 120 39.2 120 39.2 120
Ling Liang Church E Wun
Secondary School 39.2 40 39.2 40 39.2 40 39.2 40
Yu Tung Court 36.8 100 36.8 100 36.8 100 36.8 100
Tung Chung Crescent 36.8 120 36.8 120 36.8 120 36.8 120
Ching Chung Hau Po Woon
Primary School 36.8 40 36.8 40 36.8 40 36.8 40
Criterion 125 - 125 - 125 - 125 -
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Long-term Impact
Assessment of impacts to annual average air quality has considered the nine
scenarios as shown in Table 4.17.
It should be highlighted that there is considerable reduction in total annual
emission loading from CAPCO power generation facilities as a result of the
operation of the additional CCGT unit(s). The total annual emission loading
from CAPCO power generation facilities under different operation scenarios
are summarised in Table 4.44. For all operation scenarios with Project (i.e.
Scenarios 2a to 2d and 3a to 3d), there will be reduction in the total annual
emissions of NOx, SO2 and RSP, where the extent of reduction depends on the
amount of displacement of existing gas-fired generation and/or coal-fired
generation by the Project. The highest reduction in total annual emission
loading occurs when power generation from two additional CCGT units
(600MW) displaces existing gas-fired and coal-fired power generation from
BPPS and CPPS (i.e. Scenario 3d), in which the annual emission loading
reduction for NOx, SO2 and RSP when compared with the “without Project”
scenario is expected to be 33.1%, 17.8% and 18.8%, respectively. It should be
noted that all these operation scenarios are considered to be the potential
operation scenarios that may occur during the actual operation of the Project.
Table 4.44 Total Annual Emission Loading from CAPCO Power Generation Facilities
under Different Operation Scenarios
Operation
Scenario
Total Annual Emission Loading
(Tonne)
Percentage Reduction Compared to
Without Project Scenario (Scenario 1)
NOx SO2 RSP NOx SO2 RSP
1 (a) 14,918 4,538 439 - - -
2a (b) 14,568 4,518 437 2.3% 0.4% 0.5%
2b (c) 12,590 4,141 400 15.6% 8.8% 9.0%
2c (d) 14,461 4,512 436 3.1% 0.6% 0.8%
2d (e) 12,029 4,053 390 19.4% 10.7% 11.2%
3a (f) 14,307 4,504 435 4.0% 0.7% 0.9%
3b (g) 11,051 3,898 375 25.9% 14.1% 14.5%
3c (h) 14,150 4,495 433 5.1% 0.9% 1.3%
3d (i) 9,976 3,728 356 33.1% 17.8% 18.8%
Notes:
(a) CAPCO operation without Project
(b) 1x 440MW CCGT send-out displacing gas-fired send-out from BPPS
(c) 1x 440MW CCGT send-out displacing both existing gas-fired send-out from BPPS and
coal-fired send-out from CPPS
(d) 1x 600MW CCGT send-out displacing gas-fired send-out from BPPS
(e) 1x 600MW CCGT send-out displacing both existing gas-fired send-out from BPPS and
coal-fired send-out from CPPS
(f) 2x 440MW CCGT send-out displacing gas-fired send-out from BPPS
(g) 2x 440MW CCGT send-out displacing both existing gas-fired send-out from BPPS and
coal-fired send-out from CPPS
(h) 2x 600MW CCGT send-out displacing gas-fired send-out from BPPS
(i) 2x 600MW CCGT send-out displacing both existing gas-fired send-out from BPPS and
coal-fired send-out from CPPS
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Table 4.45 to Table 4.47 show the maximum modelled annual average total
concentration for NO2, RSP (PM10) and FSP (PM2.5) respectively along with the
height at which the maximum modelled concentration was predicted to occur.
As NO2 is considered the potential key air pollutant associated with the
operation of the CCGT units, contours of the annual average NO2
concentrations for Scenario 1 (1) and Scenario 2a (2 ) in different AoIs are
presented in Figure 4.28 to Figure 4.32, and Figure 4.33 to Figure 4.37,
respectively.
Review of Table 4.45 to Table 4.47 indicates that the maximum predicted
concentration does not change substantially between the scenarios. An in-
depth review of the detailed results tables in Annex 4F shows that a difference
between the scenarios is not observable until the third or fourth decimal place.
The assessment results indicate that cumulative impacts from all considered
sources and background do not result in an exceedance of annual average
criteria, with the exception of annual NO2 impact at Parkview Court in the
Tuen Mun area.
A consideration of source apportionment for NO2 concentrations at Parkview
Court has been used to determine the contribution of the Project under the
various considered scenarios. Chart 4.1 shows the detailed breakdown of
NO2 contributions from all sources for each of the relevant heights considered.
For annual NO2 impact at Parkview Court, it can be seen from that the
background and road emissions dominate with a decreasing contribution of
road emissions with height, and that the predicted concentrations comply
with annual average criterion for levels higher than 10m above ground.
Therefore, exceedances of cumulative annual average NO2 concentrations
were predicted at Parkview Court at level up to 5m above ground level only
(which mainly affect the club house of the building).
(1) CAPCO operation without Project
(2) 1x 440MW CCGT generation displacing gas-fired generation from BPPS
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Table 4.45 Predicted Cumulative Annual Average NO2 Concentrations (µg m-3) at the Identified ASRs within the AoIs
AoI ASR
Scenario 1 Scenario 2a Scenario 2b Scenario 2c Scenario 2d Scenario 3a Scenario 3b Scenario 3c Scenario 3d
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 29.3 1.5 29.3 1.5 29.3 1.5 29.3 1.5 29.3 1.5 29.3 1.5 29.2 1.5 29.3 1.5 29.2 1.5
Melody Garden 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5
Siu Shan Court 29.2 1.5 29.2 1.5 29.2 1.5 29.2 1.5 29.2 1.5 29.2 1.5 29.2 1.5 29.2 1.5 29.2 1.5
Tin Shui
Wai
Tin Shui Estate 26.8 1.5 26.8 1.5 26.8 1.5 26.8 1.5 26.8 1.5 26.8 1.5 26.7 1.5 26.8 1.5 26.7 1.5
Tin Yan Estate 26.3 1.5 26.3 1.5 26.3 1.5 26.3 1.5 26.3 1.5 26.3 1.5 26.3 1.5 26.3 1.5 26.3 1.5
Tin Wah Estate 26.5 1.5 26.5 1.5 26.5 1.5 26.5 1.5 26.5 1.5 26.5 1.5 26.5 1.5 26.5 1.5 26.5 1.5
Tin Chung
Court 25.8 1.5 25.8 1.5 25.8 1.5 25.8 1.5 25.8 1.5 25.8 1.5 25.8 1.5 25.8 1.5 25.7 1.5
Low-rise
building on Man
Tak Road
28.1 1.5 28.1 1.5 28.1 1.5 28.1 1.5 28.1 1.5 28.1 1.5 28.1 1.5 28.1 1.5 28.1 1.5
Tuen
Mun
Lakeshore
Building 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5
Parkview Court 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5
Kam Hing
Building 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5
Tuen Mun Town
Plaza 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5
On Ting Estate 25.8 1.5 25.7 1.5 25.7 1.5 25.7 1.5 25.7 1.5 25.7 1.5 25.7 1.5 25.7 1.5 25.7 1.5
Chi Lok Fa Yuen 27.8 1.5 27.8 1.5 27.8 1.5 27.8 1.5 27.8 1.5 27.8 1.5 27.8 1.5 27.8 1.5 27.8 1.5
Yuen
Long
Shui Pin Tsuen 32.0 1.5 32.0 1.5 32.0 1.5 32.0 1.5 32.0 1.5 32.0 1.5 32.0 1.5 32.0 1.5 32.0 1.5
Man Cheong
Building 33.1 1.5 33.1 1.5 33.1 1.5 33.1 1.5 33.1 1.5 33.1 1.5 33.1 1.5 33.1 1.5 33.1 1.5
Tung
Chung
Seaview Cresent 34.9 1.5 34.9 1.5 34.9 1.5 34.9 1.5 34.9 1.5 34.9 1.5 34.9 1.5 34.9 1.5 34.9 1.5
Coastal Skyline
La Rossa 35.0 1.5 35.0 1.5 35.0 1.5 35.0 1.5 35.0 1.5 35.0 1.5 35.0 1.5 35.0 1.5 35.0 1.5
Ling Liang
Church E Wun
Secondary
School 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5 36.8 1.5
Yu Tung Court 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5
Tung Chung
Crescent 29.0 1.5 29.0 1.5 29.0 1.5 29.0 1.5 29.0 1.5 29.0 1.5 29.0 1.5 29.0 1.5 29.0 1.5
Ching Chung
Hau Po Woon
Primary School 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5
Criterion 40 - 40 - 40 - 40 - 40 - 40 - 40 - 40 - 40 -
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Table 4.46 Predicted Cumulative Annual Average RSP( PM10) Concentrations (µg m-3) at the Identified ASRs within the AoIs
AoI ASR
Scenario 1 Scenario 2a Scenario 2b Scenario 2c Scenario 2d Scenario 3a Scenario 3b Scenario 3c Scenario 3d
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5
Melody Garden 42.8 1.5 42.8 1.5 42.8 1.5 42.8 1.5 42.8 1.5 42.8 1.5 42.8 1.5 42.8 1.5 42.8 1.5
Siu Shan Court 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5 41.6 1.5
Tin Shui
Wai
Tin Shui Estate 43.3 1.5 43.3 1.5 43.3 1.5 43.3 1.5 43.3 1.5 43.3 1.5 43.3 1.5 43.3 1.5 43.3 1.5
Tin Yan Estate 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5
Tin Wah Estate 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5
Tin Chung
Court 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5 43.4 1.5
Low-rise
building on Man
Tak Road
44.0 1.5 44.0 1.5 44.0 1.5 44.0 1.5 44.0 1.5 44.0 1.5 44.0 1.5 44.0 1.5 44.0 1.5
Tuen
Mun
Lakeshore
Building 42.7 1.5 42.7 1.5 42.9 1.5 42.7 1.5 42.7 1.5 42.7 1.5 42.7 1.5 42.7 1.5 42.7 1.5
Parkview Court 44.7 1.5 44.7 1.5 44.6 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5 44.7 1.5
Kam Hing
Building 44.3 1.5 44.3 1.5 44.3 1.5 44.3 1.5 44.3 1.5 44.3 1.5 44.3 1.5 44.3 1.5 44.3 1.5
Tuen Mun Town
Plaza 44.6 1.5 44.6 1.5 44.5 1.5 44.6 1.5 44.6 1.5 44.6 1.5 44.6 1.5 44.6 1.5 44.6 1.5
On Ting Estate 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5
Chi Lok Fa Yuen 41.9 1.5 41.9 1.5 42.0 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5 41.9 1.5
Yuen
Long
Shui Pin Tsuen 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5
Man Cheong
Building 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5 43.9 1.5
Tung
Chung
Seaview Cresent 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5
Coastal Skyline
La Rossa 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5 40.1 1.5
Ling Liang
Church E Wun
Secondary
School 40.2 1.5 40.2 1.5 40.2 1.5 40.2 1.5 40.2 1.5 40.2 1.5 40.2 1.5 40.2 1.5 40.2 1.5
Yu Tung Court 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5
Tung Chung
Crescent 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5
Ching Chung
Hau Po Woon
Primary School 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5 39.5 1.5
Criterion 50 - 50 - 50 - 50 - 50 - 50 - 50 - 50 - 50 -
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Table 4.47 Predicted Cumulative Annual Average FSP (PM2.5) Concentrations (µg m-3) at the Identified ASRs within the AoIs
AoI ASR
Scenario 1 Scenario 2a Scenario 2b Scenario 2c Scenario 2d Scenario 3a Scenario 3b Scenario 3c Scenario 3d
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Maximum
Modelled
Height of
maximum
Butterfly
Estate
Butterfly Estate 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5
Melody Garden 30.4 1.5 30.4 1.5 30.4 1.5 30.4 1.5 30.4 1.5 30.4 1.5 30.4 1.5 30.4 1.5 30.4 1.5
Siu Shan Court 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5 29.6 1.5
Tin Shui
Wai
Tin Shui Estate 30.7 1.5 30.7 1.5 30.7 1.5 30.7 1.5 30.7 1.5 30.7 1.5 30.7 1.5 30.7 1.5 30.7 1.5
Tin Yan Estate 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5
Tin Wah Estate 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5 30.9 1.5
Tin Chung
Court 30.8 1.5 30.8 1.5 30.8 1.5 30.8 1.5 30.8 1.5 30.8 1.5 30.8 1.5 30.8 1.5 30.8 1.5
Low-rise
building on Man
Tak Road
31.3 1.5 31.3 1.5 31.3 1.5 31.3 1.5 31.3 1.5 31.3 1.5 31.3 1.5 31.3 1.5 31.3 1.5
Tuen
Mun
Lakeshore
Building 30.6 1.5 30.6 1.5 30.6 1.5 30.6 1.5 30.6 1.5 30.6 1.5 30.6 1.5 30.6 1.5 30.6 1.5
Parkview Court 31.9 1.5 31.9 1.5 31.9 1.5 31.9 1.5 31.9 1.5 31.9 1.5 31.9 1.5 31.9 1.5 31.9 1.5
Kam Hing
Building 31.5 1.5 31.5 1.5 31.5 1.5 31.5 1.5 31.5 1.5 31.5 1.5 31.5 1.5 31.5 1.5 31.5 1.5
Tuen Mun Town
Plaza 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5 31.7 1.5
On Ting Estate 29.8 1.5 29.8 1.5 29.8 1.5 29.8 1.5 29.8 1.5 29.8 1.5 29.8 1.5 29.8 1.5 29.8 1.5
Chi Lok Fa Yuen 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5 29.9 1.5
Yuen
Long
Shui Pin Tsuen 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5
Man Cheong
Building 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5 31.2 1.5
Tung
Chung
Seaview Cresent 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5
Coastal Skyline
La Rossa 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5 28.5 1.5
Ling Liang
Church E Wun
Secondary
School 28.6 1.5 28.6 1.5 28.6 1.5 28.6 1.5 28.6 1.5 28.6 1.5 28.6 1.5 28.6 1.5 28.6 1.5
Yu Tung Court 28.2 1.5 28.2 1.5 28.2 1.5 28.2 1.5 28.2 1.5 28.2 1.5 28.2 1.5 28.2 1.5 28.2 1.5
Tung Chung
Crescent 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5
Ching Chung
Hau Po Woon
Primary School 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5 28.3 1.5
Criterion 35 - 35 - 35 - 35 - 35 - 35 - 35 - 35 - 35 -
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Chart 4.1 Source Apportionment for NO2 Annual Average at Parkview Court in Tuen Mun for Relevant Heights
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Chart 4.2 Source Apportionment for NO2 Annual Average at Parkview Court in Tuen Mun for Relevant Heights with Roads and Background Removed
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Chart 4.2 shows the source apportionment with both the roads and the
background removed in order that the relative contributions of the power
generation sources (i.e. BPPS, CPA, CPB and CCGT units) included in the
scenarios can be seen.
Whilst the maximum predicted total NO2 concentration is at 1.5 m, the
maximum contribution from the power station occurs at 100 m. Contribution
from the power generation sources to the predicted cumulative annual
average NO2 is considered insignificant with a maximum contribution in
Scenario 1 of 0.12 µg m-3 at a height of 100 m.
At all considered heights, total contribution from the power generation
facilities to the predicted cumulative annual average NO2 concentrations are
lower for each of the considered scenarios (Scenarios 2a to 3d) in comparison
to the “without project” scenario (Scenario 1). Like for like scenarios (e.g.
Scenarios 2a, 2c, 3a and 3c) show increased improvement as the size of the
Project power generation is increased. The greatest improvement in NO2
contribution from the modelled power generation sources occurs for Scenario
3d, which is for the construction of two 600MW turbines with offset of power
generation from both coal and other gas turbine sources. This analysis
showed that the exceedance of annual NO2 at Parkview Court is entirely due
to background and road traffic emissions. Hence, unacceptable long-term air
quality impact arising from the operation of Project is not anticipated.
The assessment of long-term impact assumes the monthly emissions loading
from CAPCO’s power generation facilities remains the same throughout the
year. However, in reality, the monthly emission loading varies throughout
the year. An analysis of the monthly emission loading of BPPS, CPA and
CPB in 2013 and 2014 has been carried out. Higher percentage increases in
NOx emission loading when comparing with the annual average were
recorded in 2013. The monthly NOx emissions from BPPS, CPA and CPB in
2013 and the corresponding percentage change relative to the annual averaged
NOx emissions in 2013 are shown in Table 4.48.
Table 4.48 Monthly NOx Emissions from CAPCO Power Generation Facilities and
Percentage Change Relative to the Annual Averaged NOx Emissions in 2013
Month Monthly NOx Emissions (kilo-
tonnes)
Percentage Difference Compared to
Annual Average NOx Emissions
CPA CPB BPPS CPA CPB BPPS
Jan-13 0.5 1.2 0.08 -38.3 -5.9 -12.1
Feb-13 0.5 1.0 0.06 -37.9 -22.9 -29.9
Mar-13 0.8 1.3 0.09 +1.9 -3.8 -1.2
Apr-13 1.0 1.2 0.09 +40.4 -6.0 +3.7
May-13 1.1 1.8 0.09 +50.1 (a) +38.2 (a) +2.1
Jun-13 0.7 1.5 0.11 -8.6 +13.6 +23.7
Jul-13 0.6 1.1 0.12 -13.4 -14.0 +30.9
Aug-13 0.9 1.4 0.13 +20.0 +3.1 +40.2 (a)
Sep-13 0.5 1.4 0.11 -34.7 +3.6 +26.6
Oct-13 0.6 1.3 0.06 -15.1 +1.4 -30.0
Nov-13 0.9 1.4 0.04 +20.7 +4.3 -49.9
Dec-13 0.9 1.2 0.09 +15.1 -11.8 -4.2
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Month Monthly NOx Emissions (kilo-
tonnes)
Percentage Difference Compared to
Annual Average NOx Emissions
CPA CPB BPPS CPA CPB BPPS
Average 0.7 1.3 0.1 - - -
Note:
(a) Highest percentage increase when compared to annual average NOx emissions.
In 2013, the peak monthly NOx emission loading for BPPS, CPA and CPB is
40.2%, 50.1% and 38.2% higher than the annual average NOx emissions,
respectively. This percentage increase could be applied to the annual NO2
contributions from BPPS, CPA and CPB (which is overly conservative since
this assumes peak monthly emission for the entire year) at the ASRs to take
into account the impact of monthly emission variations.
As described in Annex 4F which shows the breakdown of contributions from
each emission source, total annual NO2, RSP and FSP contributions from
BPPS, CPA, CPB and CCGT unit(s) are insignificant compared with
contributions from background sources and road traffic. Two ASRs, TM3
(Tuen Mun Town Plaza) and TSW4 (Tin Shui Estate) have been selected for
the analysis of the impact of monthly emission variations from the CAPCO’s
power generation facilities. Assessment results show that cumulative annual
average NO2 concentration at TM3 is very close to the annual NO2 criterion,
while the total contribution from the CAPCO’s power generation facilities is
predicted to be the highest at TSW4.
The predicted cumulative annual average NO2 concentration at TM3 is 39.5 µg
m-3. As shown in Annex 4F, annual NO2 contributions from BPPS, CPA and
CPB at TM3 are only 0.023 µg m-3, 0.016 µg m-3 and 0.023 µg m-3, respectively,
for Scenario 1 (without Project), with a total of 0.06 µg m-3, or 0.15% of the total
concentration. The adjusted annual NO2 contributions from BPPS, CPA and
CPB taking into account the impact of monthly emission variations are still
only 0.032 µg m-3, 0.024 µg m-3 and 0.032 µg m-3, respectively, for Scenario 1
(without Project), with a total of 0.088 µg m-3. This remains insignificant (<
1%) compared to contributions from background sources and road traffic.
With consideration of the monthly variations of emission loading, the
predicted cumulative annual average NO2 concentration at TM3 would still
comply with the annual NO2 criterion.
Total contributions from CAPCO’s power generation facilities are the highest
at TSW4, where the predicted annual NO2 contributions from BPPS, CPA and
CPB are 0.123 µg m-3, 0.126 µg m-3 and 0.145 µg m-3, respectively, for Scenario 1
(without Project), with a total of 0.39 µg m-3, or 1.5% of the total concentration.
The predicted cumulative annual average NO2 concentration at TSW4 is 26.8
µg m-3. The adjusted annual NO2 contributions from BPPS, CPA and CPB
due to the impact of monthly emission variations are 0.172 µg m-3, 0.189 µg m-3
and 0.2 µg m-3, respectively, for Scenario 1 (without Project), with a total of
0.56 µg m-3. Therefore, taking into account the impact of monthly emission
variations, the predicted cumulative annual average NO2 concentration at
TSW4 would be about 27.4 µg m-3, which is still well within the annual NO2
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criterion. In addition, the maximum annual NO2 contribution arising from
the operation of the additional CCGT unit(s) is insignificant (i.e. from 0.02% of
total concentration for Scenario 2a (1 ) to 0.06% of total concentration for
Scenario 3d (2)).
It can be concluded that, with such small predicted annual contributions from
the power plants, the impact due to seasonal emission variations is also
insignificant and has a minimal effect to the cumulative annual concentrations
at the concerned ASRs.
4.8.3 Results of Ozone Modelling by PATH Model
The potential ozone impact within the AoIs was reviewed by running the
PATH model for Year 2020 for “without Project” scenario and “with Project”
scenarios (i.e. operation of one or two additional CCGT units). Table 4.49
presents the potential change in ozone levels based on comparison between
“without Project” scenario and “with Project” scenarios predicted by the
PATH model in different AoIs. Predicted hourly ozone results for the two
scenarios are provided in Annex 4G. Modelled results showed that the
potential change in ozone levels due to the operation of one or two additional
CCGT units is minimal. Adverse ozone impact arising from the operation of
the Project is not anticipated.
Table 4.49 Change in Ozone Levels between Scenarios with and Without the Project in
Different AoIs
Area PATH Grid Difference in O3 (µg m-3)
for Operation of One
CCGT Unit
Difference in O3 (µg m-3) for
Operation of Two CCGT
Units
Butterfly Estate 13,32 0.1 0.1
14,32 0.1 0.1
Tin Shui Wai 15,39 0.1 0.1
16,38 0.1 0.1
16,39 0.1 0.1
Tuen Mun 14,33 0.1 0.1
14,34 0.1 0.1
15,33 0.1 0.1
15,34 0.1 0.1
Yuen Long 18,37 0.1 0.1
18.38 0.1 0.1
Tung Chung 12,25 0.1 0.1
12,26 0.0 0.0
(1) 1 x 440MW CCGT generation displacing gas-fired generation from BPPS
(2) 2 x 600MW CCGT generation displacing both existing gas-fired generation from BPPS and coal-fired generation
from CPPS
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4.9 RESIDUAL IMPACTS
4.9.1 Short-term Impact
As discussed in Section 4.8.2, the cumulative short-term air quality impact for
NO2, SO2, RSP (PM10) and FSP (PM2.5) at the concerned ASRs comply with the
relevant AQO criteria. Hence, no adverse residual impact with respect to
short-term air quality impact is anticipated.
4.9.2 Long-term Impact
As discussed in Section 4.8.2, the cumulative long-term air quality impact for
NO2, RSP (PM10) and FSP (PM2.5) at the concerned ASRs comply with the
relevant AQO criteria, except for annual average NO2 impact at Parkview
Court in the Tuen Mun area. However, detailed analysis show that the
exceedance of annual average NO2 impact at Parkview Court is entirely due to
the existing background and road traffic emissions, while the annual average
NO2 contribution from the CAPCO power generation facilities at this ASR is
insignificant (a maximum of 0.12 µg m-3 at the height of 100m for Scenario 1
without Project, which is about 0.3% of the annual average NO2 criterion). In
fact, the predicted cumulative annual NO2 concentration at this ASR will
reduce with the operation of the Project, although insignificant when
compared to contributions from background and vehicular emissions.
Hence, no adverse residual impact with respect to long-term air quality
impact is anticipated.
4.10 MITIGATION MEASURES
4.10.1 Construction Phase
The following dust control measures stipulated in the Air Pollution Control
(Construction Dust) Regulations and good site practices will be incorporated
into the Contract Specifications and implemented throughout the construction
period:
Impervious dust screen or sheeting will be provided to enclose
scaffolding from the ground floor level of building for construction of superstructure of the new buildings;
Impervious sheet will be provided for skip hoist for material transport;
The area where dusty work takes place should be sprayed with water or a
dust suppression chemical immediately prior to, during and immediately after dusty activities as far as practicable;
All dusty materials should be sprayed with water or a dust suppression
chemical immediately prior to any loading, unloading or transfer operation;
Dropping heights for excavated materials should be controlled to a
practical height to minimise the fugitive dust arising from unloading;
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During transportation by truck, materials should not be loaded to a level
higher than the side and tail boards, and should be dampened or covered before transport;
Wheel washing device should be provided at the exits of the work sites.
Immediately before leaving a construction site, every vehicle shall be washed to remove any dusty material from its body and wheels as far as practicable;
Road sections between vehicle-wash areas and vehicular entrance will be
paved;
Hoarding of not less than 2.4m high from ground level will be provided
along the length of the Project Site boundary;
Haul roads will be kept clear of dusty materials and will be sprayed with water so as to maintain the entire road surface wet at all times;
Temporary stockpiles of dusty materials will be either covered entirely by
impervious sheets or sprayed with water to maintain the entire surface wet all the time;
Stockpiles of more than 20 bags of cement, dry pulverised fuel ash and
dusty construction materials will be covered entirely by impervious sheeting sheltered on top and 3-sides;
All exposed areas will be kept wet to minimise dust emission;
ULSD will be used for all construction plant on-site, as 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;
The engine of the construction equipment during idling will be switched
off; and
Regular maintenance of construction equipment deployed on-site will be
conducted to prevent black smoke emission.
4.10.2 Operation Phase
As discussed in Section 4.6.4, a number of operation scenarios have been considered to represent potential future operation regimes for CAPCO power generation facilities (with and without Project) as a whole. It has been demonstrated that, with the implementation of the Project, there will be reduction of annual emission loadings from CAPCO power generation
facilities as a whole. Under normal operation, the additional CCGT units will be operated as a priority plant. The send-out from the additional CCGT units will normally displace both the coal-fired send-out from CPPS and gas-fired send-out from BPPS. As power generation from the additional CCGT units is more efficient with lower pollutant emissions, the total emission loadings and potential air quality impact arising from CAPCO power generation facilities as a whole can be minimised.
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With proper maintenance of the additional CCGT units on a regular basis, no additional mitigation measures are required during the operation phase.
4.11 ENVIRONMENTAL MONITORING AND AUDIT
4.11.1 Construction Phase
No adverse fugitive dust impact is anticipated during the construction period,
dust monitoring is considered not necessary. However, it is recommended to
conduct regular environmental site audit, i.e. on weekly basis, to ensure the
implementation of the dust control measures and good site practices as
recommended in Section 4.9.1 throughout the construction period.
4.11.2 Operation Phase
No adverse air quality impact is anticipated during the operation of the
additional CCGT units. However, it is recommended to continuously
monitor and record the levels of air pollutants of the exhaust gas streams
emitted from the stacks of the additional CCGT units by means of Continuous
Emission Monitoring System (CEMS). The parameters to be measured by the
CEMS per the licence requirements. Continuous monitoring of ambient
concentrations of SO2, NO and NO2 will be continued at the current CLP’s
AQMSs.
4.12 CONCLUSION
4.12.1 Construction Phase
All construction works associated with the construction of additional CCGT
units will be carried out within the existing BPPS boundary. The nearest
identified ASR is located more than 1km away from the Project Site boundary.
Due to the large separation distance between the work site and the nearest
ASR, adverse dust impacts arising from the construction activities of the
Project are not anticipated.
The Project construction site is small, with relative small quantities of C&D
materials and excavated materials will be generated from site clearance and
the construction of the additional CCGT units, respectively. Due to the
generation of small quantities of C&D materials and excavated materials that
require off-site disposal, the number of truck trips required per day is limited.
The potential air quality impact due to vehicular emissions from additional
trucks during the construction phase of the Project is minimal.
Furthermore, major equipment for the Project will be transported to the
Project site by barges, as far as practicable, in order to minimise the number of
additional vehicles on the roads due to the construction of the Project.
With the implementation of dust control measures, proper site management
and good housekeeping, no adverse fugitive dust impact is expected from the
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demolition and construction works. Also, due to the high moisture of the
dredged marine sediments, no fugitive dust emission is expected.
4.12.2 Operation Phase
An assessment of potential impacts to ambient air quality from the proposed
installation of the additional CCGT unit(s) at BPPS has been undertaken. The
assessment has considered the installation of:
1 × 440MW CCGT unit;
2 × 440MW CCGT units;
1 × 600MW CCGT unit; and
2 × 600MW CCGT units.
An initial screening assessment was undertaken to determine the ASRs of
interest. It was found that contribution from the proposed additional
generation capacity was minimal, however current monitoring in certain areas
indicated that ambient air quality already exceeded the standard in these
areas. Atmospheric dispersion modelling was therefore used to determine
the likely ambient air quality at ASRs within the AoI that currently exceeds
the ambient air quality standards.
For the cumulative air quality impact within the AoI, a number of emission
sources have been considered, including emissions from:
One or two proposed additional CCGT units at BPPS;
Existing BPPS, CPA and CPB;
Roads near to the considered ASRs; and
Modelled PATH background in 2020, including major air emissions from
industrial facilities along Lung Mun Road such as Shiu Wing Steel Mill,
Green Island Cement and EcoPark in Tuen Mun Area 38.
Dispersion modelling used the CALINE4 model for roads, the ISCST3 model
for power generation sources and the PATH model to determine background
from other sources within the Hong Kong Airshed and transboundary
contributions. The proposed opening year for the initial stage of the Project
is 2020. Examination of vehicular emission databases and the PATH model
indicates that worst case ambient concentrations from these sources are likely
to occur in 2020, with improvements thereafter. Dispersion modelling was
therefore undertaken for the opening year (2020).
Consideration was given to both short-term and long-term ambient air quality
criteria. For the assessment of short-term air quality impact, it was assumed
that the proposed CCGT units are operating at the emission limits specified in
BPM 7/1 (2014) as a conservative assessment. For the operation of one or two
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additional CCGT units, two power scenarios were considered, two 440MW
and two 600MW class turbines. In each power generation scenario, both
normal operation and back-up operation of the CCGT units using diesel fuel
were assessed. The predicted cumulative 1-hour NO2, 24-hour RSP (PM10),
24-hour FSP (PM2.5), 10-minute SO2 and 24-hour SO2 at the concerned ASRs
comply with their relevant ambient air quality criteria during the operation of
one or two additional CCGT units.
The assessment of the cumulative long-term impacts has considered different
operation scenarios meeting the 2020 Emission Cap. The anticipated
emissions for the scenarios were based on the annual average electricity
generation with a diurnal profile fitted to allow more generation, and thus
more emissions, to occur during the day period compared to the night period.
This approach provides a likely conservative, but realistic approach to the
annual emissions profile. For all the assessed operation scenarios with
Project, there will be reduction in the total annual emissions of NOx, SO2 and
RSP when comparing with the 2020 emission cap. For the one new CCGT
scenarios, significant reduction in emissions are predicted ranging between 8.8
to 15.6% for 440MW CCGT and 10.7 to 19.4% for 600MW CCGT. Further
reductions in emissions are shown in the two new CCGT scenarios ranging
between 14.1 to 25.9% for 440MW CCGT and 17.8 to 33.1% for 600MW CCGT.
For the displacing gas-fired generation only scenarios, reduction in emissions
are still demonstrated under worst case situation with least reduction ranging
between 0.4 to 2.3% for one 440 MW CCGT.
Results from the annual average modelling demonstrated that annual average
concentrations for NO2, RSP (PM10) and FSP (PM2.5) were below the
assessment criteria at all locations with the exception of Parkview Court in
Tuen Mun. Evaluation of source contribution at Parkview Court indicates
that background and road contributions are the most significant sources of
impact at ground level (up to 5m above ground level). The impact mainly
affects the club house of the building.
When the background and vehicular emission contributions are removed, the
maximum impact from the power generation sources occurs at 100 m.
Contribution to annual average NO2 from the modelled power generation
sources is considered insignificant with a maximum contribution in Scenario 1 (1) of 0.12 µg m-3 (which is about 0.3% of the AQO criterion) at a height of 100
m.
At all relevant heights, total contribution from modelled power generation
facilities to predicted annual average NO2 concentrations are lower for each of
the considered scenarios (Scenarios 2a (2) to 3d (3)) in comparison to the do-
(1) CAPCO operation without Project
(2) 1 x 440MW CCGT generation displacing gas-fired generation from BPPS
(3) 2 x 600MW CCGT generation displacing both existing gas-fired generation from BPPS and coal-fired generation
from CPPS
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nothing (Scenario 1). Like for like scenarios (e.g. Scenarios 2a, 2c (1), 3a (2) and
3c (3)) show increased improvement as the size of the Project power generation
is increased. The greatest improvement in NO2 contribution from the
modelled power generation sources occurs for Scenario 3d, which is for the
operation of two 600MW turbines with offset of power generation from both
coal-fired units (i.e. CPA and CPB) and gas-fired units (i.e. existing BPPS).
Overall, it is concluded that the contribution from the Project emission to
ambient air quality at the identified representative ASRs is insignificant.
The potential change in ozone levels due to the operation of the additional
CCGT units was also assessed by PATH modelling. Modelled results
showed that the operation of the additional CCGT units will have minimal
effect on the ambient ozone levels.
(1) 1 x 600MW CCGT generation displacing gas-fired generation from BPPS
(2) 2 x 440MW CCGT generation displacing gas-fired generation from BPPS
(3) 2 x 600MW CCGT generation displacing gas-fired generation from BPPS