4 air quality 4.1 introduction · 4 air quality 4.1 introduction this section presents the...

ENVIRONMENTAL RESOURCES MANAGEMENT CASTLE PEAK POWER COMPANY LIMITED

0308057_S4_AQIA_REV 3_V1.DOCX APRIL 2016

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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


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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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


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


TC2a Seaview Crescent Residential 13.5 120

TC2b Coastal Skyline La

Rossa


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




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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)


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.


(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)


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.


Table 4.6 Concentrations of Air Pollutants Measured at CLP’s Butterfly Estate AQMS

in the Recent 5 Years (2010 - 2014)


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.


(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



19th highest

1-hour NO2


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


Table 4.8 Concentrations of Air Pollutants Measured at CLP’s Lung Kwu Tan AQMS in



19th highest

1-hour NO2


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



19th highest

1-hour NO2


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


Table 4.10 Concentrations of Air Pollutants Measured at CLP’s San Hui/Tuen Mun

Clinic AQMS in the Recent 5 Years (2010 - 2014)


19th highest

1-hour NO2


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.


(c) No 10-minute SO2 monitoring was conducted from 2010 to 2013 (i.e. before the 10-min


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



4-16

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.



4-17

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.



4-18

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).



4-19


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



4-20

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


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



4-21

Operation

Mode


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.



4-22

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.



4-23

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-


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-


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-


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).



4-24

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)).



4-25

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.



4-26

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



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.


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.



4-27

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.



4-28

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



recorded mixing height by the Hong Kong Observatory

(HKO) (ie, 121m) in 2010 were adjusted to 121m.


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.



4-29

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)


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


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


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


Shiu Wing Steel Mill

(SWSM)

Emission sources were added SP Licence

Eco Park in Tuen Mun

Area 38



International Airport into a Three-

Runway System (AEIAR-

185/2014)


Facility (PAFF)




Landfill (PPVL)



(STF)





4-30



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



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


“Without Project” Scenario




without Project

Scenario 1 in Table 4.17 and

Annex 4B


Shiu Wing Steel Mill (SWSM) Emission sources were added SP Licence

Eco Park in Tuen Mun Area

38



International Airport into a

Three-Runway System (AEIAR-

185/2014)


Facility (PAFF)




Landfill (PPVL)



(STF)





4-31



extension

Emission sources were added Report

Lamma Island Power Station Stack emissions were updated



Emission Allowances

“With Project” Scenario – operation of one additional CCGT units (a)




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




38





185/2014)


Facility (PAFF)


Butterfly Beach Laundry Emission sources were added.


Landfill (PPVL)



(STF)



Report Existing WENT landfill and

extension





Emission Allowances

“With Project” Scenario – operation of two additional CCGT units (b)




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




38





185/2014)


Facility (PAFF)


Butterfly Beach Laundry Emission sources were added.


Landfill (PPVL)



(STF)



Report Existing WENT landfill and

extension





Emission Allowances



4-32


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



4-33

[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.



4-34

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.



4-35

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



4-36

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



4-37

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



4-38

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.



4-39

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



4-40

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.



4-41

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


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



4-42


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


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 440MW back-up using diesel fuel;





4-43




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.



4-44

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


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 -



4-45

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


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5

Tuen

Mun


Parkview Court 87.2 1.5 87.2 1.5 87.2 1.5 87.2 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


Tung

Chung

Seaview Crescent 79.0 1.5 79.0 1.5 79.0 1.5 79.0 1.5




Yu Tung Court 78.3 1.5 78.3 1.5 78.3 1.5 78.3 1.5



Primary School 78.5 1.5 78.5 1.5 78.5 1.5 78.5 1.5

Criterion 100 - 100 - 100 - 100 -



4-46

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


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5

Tuen

Mun


Parkview Court 65.3 1.5 65.3 1.5 65.3 1.5 65.3 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


Tung

Chung





Yu Tung Court 58.9 1.5 58.9 1.5 58.9 1.5 58.9 1.5



Primary School 59.0 1.5 59.0 1.5 59.0 1.5 59.0 1.5

Criterion 75 - 75 - 75 - 75 -



4-47

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


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.



4-48

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


AoI Receptor


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 37.5 20 37.5 20 37.5 20 37.5 20

Tuen

Mun


Parkview Court 31.7 100 31.7 100 31.7 100 31.7 100



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


Tung

Chung

Seaview Cresent 39.2 120 39.2 120 39.2 120 39.2 120



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



Primary School 36.8 40 36.8 40 36.8 40 36.8 40

Criterion 125 - 125 - 125 - 125 -



4-49

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


AoI Receptor


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 152.1 1.5 152.1 1.5 152.1 1.5 152.1 1.5

Tuen

Mun


Parkview Court 157.5 1.5 157.5 1.5 159.9 1.5 159.9 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


Tung

Chung

Seaview Cresent 168.9 1.5 168.9 1.5 169.3 1.5 169.4 1.5




Yu Tung Court 130.4 1.5 130.4 1.5 130.4 1.5 130.4 1.5



Primary School 133.0 1.5 133.0 1.5 133.0 1.5 133.0 1.5

Criterion 200 - 200 - 200 - 200 -



4-50

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


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 84.0 1.5 84.0 1.5 84.0 1.5 84.0 1.5

Tuen

Mun


Parkview Court 87.2 1.5 87.2 1.5 87.2 1.5 87.3 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


Tung

Chung





Yu Tung Court 78.3 1.5 78.3 1.5 78.3 1.5 78.3 1.5



Primary School 78.5 1.5 78.5 1.5 78.5 1.5 78.5 1.5

Criterion 100 - 100 - 100 - 100 -



4-51

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


AoI Receptor


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 63.0 1.5 63.0 1.5 63.0 1.5 63.0 1.5

Tuen

Mun


Parkview Court 65.3 1.5 65.3 1.5 65.3 1.5 65.4 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


Tung

Chung





Yu Tung Court 58.9 1.5 58.9 1.5 58.9 1.5 58.9 1.5



Primary School 59.0 1.5 59.0 1.5 59.0 1.5 59.0 1.5

Criterion 75 - 75 - 75 - 75 -



4-52

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


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


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


Parkview Court 201.4 100 201.4 100 201.4 100 201.4 100



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


Tung Chung

Seaview Cresent 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


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.



4-53

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


AoI Receptor


Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Maximum

Modelled

Height of

maximum

Butterfly

Estate


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


Tak Road 37.5 20 37.5 20 37.5 20 37.5 20

Tuen

Mun


Parkview Court 31.7 100 31.7 100 31.7 100 31.7 100



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


Tung

Chung

Seaview Cresent 39.2 120 39.2 120 39.2 120 39.2 120



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



Primary School 36.8 40 36.8 40 36.8 40 36.8 40

Criterion 125 - 125 - 125 - 125 -


0308057_S4_AQIA_REV 3_V1.DOCX APRIL 2016 FEBRUARY 2016

4-54

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


(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


(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



0308057_S4_AQIA_REV 3_V1.DOCX APRIL 2016 FEBRUARY 2016

4-55

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



4-56

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 -



4-57

Table 4.46 Predicted Cumulative Annual Average RSP( PM10) Concentrations (µg m-3) at the Identified ASRs within the AoIs

AoI ASR


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


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 -



4-58

Table 4.47 Predicted Cumulative Annual Average FSP (PM2.5) Concentrations (µg m-3) at the Identified ASRs within the AoIs

AoI ASR


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


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 -



4-59

Chart 4.1 Source Apportionment for NO2 Annual Average at Parkview Court in Tuen Mun for Relevant Heights



4-60

Chart 4.2 Source Apportionment for NO2 Annual Average at Parkview Court in Tuen Mun for Relevant Heights with Roads and Background Removed



4-61

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


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.


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


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.


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


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.


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


(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.




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