Contents

                                                                                                         Page

 

3.        Air Quality impact.. 1

3.1     Introduction. 1

3.2     Environmental Legislations, Standards and Guidelines. 1

3.3     Baseline Condition. 3

3.4     Air Sensitive Receivers. 5

3.5     Identification of Environmental Impacts. 11

3.6     Construction Phase Assessment Methodology. 17

3.7     Construction Assessment Results. 20

3.8     Operation Phase Assessment Methodology. 30

3.9     Operation Phase Assessment Results. 35

3.10   Conclusion and Recommendations. 55

 

TABLES

 

Table 3.2.1       Hong Kong Air Quality Objectives (AQOs) 2

Table 3.3.1       Ambient Air Quality from 2016 – 2020 at Tai Po AQMS  4

Table 3.3.2       Summary of PATH Background Concentration in Year 2025  5

Table 3.4.1       Representative ASRs in the vicinity of the Project 6

Table 3.5.1       Summary of Potential Concurrent Projects for Construction Dust Impact 13

Table 3.6.1       Emission Factors for Construction Dust Impact Assessment 18

Table 3.6.2       Particle Size Distribution  19

Table 3.7.1       Predicted TSP Concentration at Worst Affected Level of ASRs – Unmitigated Scenario  20

Table 3.7.2       Predicted PM10 Concentration at Worst Affected Level of ASRs – Unmitigated Scenario  22

Table 3.7.3       Predicted PM2.5 Concentration at Worst Affected Level of ASRs – Unmitigated Scenario  23

Table 3.7.4       Predicted TSP Concentration at Worst Affected Level of ASRs – Mitigated Scenario  26

Table 3.7.5       Predicted PM10 Concentration at Worst Affected Level of ASRs – Mitigated Scenario  27

Table 3.7.6       Predicted PM2.5 Concentration at Worst Affected Level of ASRs – Mitigated Scenario  29

Table 3.8.1       Standard Deviation of Wind Angles for the Assessment 33

Table 3.9.1       Predicted NO2 Concentration at Worst Affected Level of ASRs – Operation Phase  35

Table 3.9.2       Predicted PM10 Concentration at Worst Affected Level of ASRs – Operation Phase  40

Table 3.9.3       Predicted PM2.5 Concentration at Worst Affected Level of ASRs – Operation Phase  44

Table 3.9.4       Predicted NO2 Concentrations under With and Without Project Scenarios  48

Table 3.9.5       Predicted PM10 Concentration under With and Without Project Scenarios  50

Table 3.9.6       Predicted PM2.5 Concentration under With and Without Project Scenarios  52

 

 

FIGURES

 

Figure 3.1a      Assessment Area for Air Quality Impact Assessment Construction Phase

Figure 3.1b      Assessment Area for Air Quality Impact Assessment Operation Phase

Figure 3.2a      Locations of Representative Air Sensitive Receivers for Construction Phase

Figure 3.2b      Locations of Representative Air Sensitive Receivers (Outside Development Area)

Figure 3.2c      Locations of Representative Air Sensitive Receivers (Outside Development Area) (Grid 34, 51)

Figure 3.2d      Locations of Representative Air Sensitive Receivers (Outside Development Area) (Grid 35, 52)

Figure 3.2e      Locations of Representative Air Sensitive Receivers (Outside Development Area) (Grid 35, 53)

Figure 3.2f      Locations of Representative Air Sensitive Receivers (Within Development Area)

Figure 3.3        Locations of Public Transport Interchange and Chimneys

Figure 3.4        Locations of Traffic Noise Mitigation for Air Quality Impact Assessment

Figure 3.5a      Contours of Cumulative 1st Hourly TSP Concentration at 1.5mAG (Construction Phase) (Mitigated)

Figure 3.5b      Contours of Cumulative 10th Daily PM10 Concentration at 1.5mAG (Construction Phase) (Mitigated)

Figure 3.5c      Contours of Cumulative Annual PM10 Concentration at 1.5mAG (Construction Phase) (Mitigated)

Figure 3.5d      Contours of Cumulative 19th Daily PM2.5 Concentration at 1.5mAG (Construction Phase) (Mitigated)

Figure 3.5e      Contours of Cumulative 36th Daily PM2.5 Concentration at 1.5mAG (Construction Phase) (Mitigated)

Figure 3.5f      Contours of Cumulative Annual PM2.5 Concentration at 1.5mAG (Construction Phase) (Mitigated)

Figure 3.6a      Contours of Cumulative 19th Hourly NO2 Concentrations at 1.5mAG (Operational Phase)

Figure 3.6b      Contours of Cumulative Annual NO2 Concentrations at 1.5mAG (Operational Phase)

Figure 3.6c      Contours of Cumulative 10th Daily PM10 Concentrations at 1.5mAG (Operational Phase)

Figure 3.6d      Contours of Cumulative Annual PM10 Concentrations at 1.5mAG (Operational Phase)

Figure 3.6e      Contours of Cumulative 19th Daily PM2.5 Concentrations at 1.5mAG (Operational Phase)

Figure 3.6f      Contours of Cumulative 36th Daily PM2.5 Concentrations at 1.5mAG (Operational Phase)

Figure 3.6g      Contours of Cumulative Annual FSP Concentrations at 1.5mAG (Operational Phase)

 

 

APPENDICES

 

Appendix 3.1              Details of ASRs

Appendix 3.2              Construction Programme, Dust Emission Inventory and Source Locations

Appendix 3.3              Detailed Construction Dust Results

Appendix 3.4              Traffic Forecast, Speed Profiles and Grouping

Appendix 3.5              Trips and Vehicle-Kilometre-Travelled (VKT)

Appendix 3.6             2019 Meteorological Data (Sheung Shui Station)

Appendix 3.7              Vehicular Emission Factors

Appendix 3.8              Sensitivity Test of Composite Vehicular Emission Factors in Operation Phase and Composite Emission Factors for CALINE4

Appendix 3.9              Surface Parameters for AERMOD Meteorological Data

Appendix 3.10             Emission Inventory and Calculations on Chimneys

Appendix 3.11             Emission Inventory and Calculations on PTIs

Appendix 3.12             Emission Inventory and Calculations on Carparks

Appendix 3.13             Predicted Pollutant Concentrations at Assessment Points – Cumulative Impact for Operation Phase

Appendix 3.14             Predicted Pollutant Concentrations at Assessment Points – Cumulative Impact for Base Phase

Appendix 3.15            Predicted Pollutant Concentrations at Assessment Points – Differences of Cumulative Impact between Operation Phase and Base Case

           

 

 


3.                       Air Quality impact

3.1                    Introduction

3.1.1                 This chapter presents an assessment of the potential air quality impacts associated with the construction and operation of the Project. The air quality impact assessment is conducted in accordance with the requirements of Annex 4 and Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) as well as the technical requirements given in Appendix B of the EIA Study Brief (ESB-318/2019).

3.2                    Environmental Legislations, Standards and Guidelines

3.2.1                 The relevant legislations, standards and guidelines applicable to the present study for the assessment of air quality include:

·       Air Pollution Control Ordinance (APCO) (Cap 311)

·       Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation

·       Air Pollution Control (Construction Dust) Regulation

·       Air Pollution Control (Smoke) Regulation

·       Air Pollution Control (Fuel Restriction) Regulation

·       Annex 4 & 12 of Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM)

·       Recommended Pollution Control Clauses for Construction Contracts

·       DEVB’s TC no. 13/2020, Timely Application of Temporary Electricity and Water Supply for Public Works Contracts and Wider Use of Electric Vehicles in Public Works Contracts

·       DEVB's TC No.1/2015, Emissions Control of NRMM in Capital Works Contracts of Public Works

Air Quality Objectives

3.2.2                 The current Air Quality Objectives (AQOs) are stipulated in terms of the maximum allowable concentrations of different kinds of air pollutants over specific time periods. The prevailing AQOs are listed in Table 3.2.1 below.

 


 

Table 3.2.1          Hong Kong Air Quality Objectives (AQOs)

Pollutant

Averaging time

Concentration limit [1]

(μg/m3)

Number of exceedances allowed

Sulphur dioxide (SO2)

10-minute

500

3

24-hour

50

3

Respirable suspended particulates (PM10) [2]

24-hour

100

9

Annual

50

Not applicable

Fine suspended particulates (PM2.5) [3]

24-hour

50

35 (18)[4]

Annual

25

Not applicable

Nitrogen dioxide (NO2)

1-hour

200

18

Annual

40

Not applicable

Ozone

8-hour

160

9

Carbon monoxide (CO)

1-hour

30,000

0

8-hour

10,000

0

Lead

Annual

0.5

Not applicable

Note:

[1] All measurements of the concentration of gaseous air pollutants, i.e., Sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide, are to be adjusted to a reference temperature of 293K and a reference pressure of 101.325KPa.

[2] Respirable suspended particulates mean suspended particles in air with a nominal aerodynamic diameter of 10μm or less.

[3] Fine suspended particulates mean suspended particles in air with a nominal aerodynamic diameter of 2.5μm or less.

[4] The value 18 inside the bracket refers to annual number of exceedances allowed of daily PM2.5 for new government projects.

    

Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation

3.2.3                 Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation specifies that all Non-road Mobile Machinery (NRMMs), except those exempted, used in specified activities and locations including construction sites, container terminals and back up facilities, restricted areas of the airport, designated waste disposal facilities and specified processes are required to comply with the prescribed emission standards.

Air Pollution Control (Construction Dust) Regulation

3.2.4                 The Air Pollution Control (Construction Dust) Regulation specifies processes that require special dust control. The Contractors are required to inform the Environmental Protection Department (EPD) and adopt proper dust suppression measures while carrying out “Notifiable Works” (which requires prior notification by the regulation) and “Regulatory Works” to meet the requirements as defined under the regulation.

Air Pollution Control (Smoke) Regulation

3.2.5                 The Air Pollution Control (Smoke) Regulation specifies that dark smoke emission from any chimney and relevant plant must not exceed 6 minutes in any period of 4hours or 3minutes continuously at any one time.

Air Pollution Control (Fuel Restriction) Regulation

3.2.6                 The Air Pollution Control (Fuel Restriction) Regulation specifies the legal control on the type of fuels to be allowed for use and the sulphur contents of the fuels. With the exception of Shatin district, the fuels to be used should comply the following respective requirements:

·       Gaseous fuel

·       Conventional solid fuel with a sulphur content not exceeding 1% by weight

·       Liquid fuel with a sulphur content not exceeding 0.005% by weight and a viscosity not more than 6centistokes at 40°C, such as Ultra Low Sulphur Diesel (“ULSD”)

Total Suspended Particulate Criteria

3.2.7                 There is no criterion on Total Suspended Particulate (TSP) under the AQOs. Annex 4 of EIAO-TM stipulates the hourly TSP concentration for construction dust impact assessment should not exceed 500 µg/m3 measured at 298K and 101.325kPa which was adopted for this assessment.

Odour Level

3.2.8                 It is also stipulated in EIAO-TM that the odour level at Air Sensitive Receivers (ASRs) should meet 5 odour units based on an averaging time of 5 seconds (5 OU/s) for odour prediction assessment.

3.3                    Baseline Condition

3.3.1                 Existing air quality of the Study Area has been determined through a review of EPD’s routine air quality monitoring data collected in 2016 to 2020. The nearest EPD air quality monitoring station (AQMS) from the Project Site is the North AQMS but the station only starts to operate from July 2020 and the next nearest is Tai Po AQMS at Tai Po Government Offices Building at Ting Kok Road in Tai Po. Its latest 5 years of air quality data (i.e. Sulphur Dioxide, Nitrogen Dioxide, Respirable and Fine Suspended Particulates and Ozone) are summarised in Table 3.3.1 to depict the trend of the localised air quality.

 


 

Table 3.3.1    Ambient Air Quality from 2016 – 2020 at Tai Po AQMS

Pollutant

Averaging Time

Conc Limits

(μg/m3)

Number of exceedances allowed

Concentration (μg/m3) [1]

Remark

2016

2017

2018

2019

2020

PM10

24-hour

100

9

74

82

69

65

58

10th highest conc.

Annual

50

N.A.

29

32

31

31

24

N.A.

PM2.5

24-hour

50

18

43

46

38

41

33

19th highest conc. [2]

Annual

25

N.A.

20

22

19

20

15

N.A.

NO2

1-hour

200

18

112

127

125

142

106

19th highest conc.

Annual

40

NA

33

39

36

36

30

NA

SO2

10-minute

500

3

37

39

24

20

19

4th highest conc.

24-hour

50

3

10

9

8

10

7

4th highest conc.

O3

8-hour

160

9

147

181

167

197

165

10th highest conc.

Note: [1] Bolded concentrations indicate exceedance of the air quality objectives

          [2] No information of the 19th highest daily FSP is available in Annual Air Quality Reports from 2016 – 2020, the 19th highest daily FSP at Tai Po AQMS were obtained from the Environmental Protection Interactive Center (https://cd.epic.epd.gov.hk/EPICDI/air/?lang=en)..

3.3.2                 The ambient air quality in the vicinity of the project site are generally complied with the AQOs. Ozone concentrations exceeded the AQO criteria in four of the last five years. However, ozone is a regional problem in Hong Kong rather than a local issue.

3.3.3                 Background pollutant concentrations as estimated by Pollutants in the Atmosphere and their Transport over Hong Kong (PATH) v2.1 model by EPD were employed in the assessment. PATH’s concentration for year 2025, which is the nearest available year from EPD’s website to the tentative commencement year in 2029, was adopted as the background concentration. The Site is located within grids (34, 51), (34, 52), (34, 53), (35, 51), (35, 52) and (35, 53) of the PATH model which are shown in Figure 3.1a and Figure 3.1b.

3.3.4                 As per Guidelines on Choices of Models and Model Parameters as published by EPD, the PM10 and PM2.5 output of PATH should be adjusted as below.

·       Annual average concentrations, PM10 (+10.3µg/m3), PM2.5 (+3.5 µg/m3)

·       Daily average concentrations, PM10 (+11 µg/m3), PM2.5 (+0 µg/m3)

3.3.5                 The NO2, PM10, PM2.5, SO2 , O3 and CO concentrations predicted by PATH in Year 2025 within the concerned grids are summarized in Table 3.3.2 below.

Table 3.3.2          Summary of PATH Background Concentration in Year 2025

Pollutant

Averaging Time

Conc. Limits

(μg/m3)

Number of Exceedances Allowed

Grid Concentration (μg/m3)

Remark

34,51

34,52

34,53

35,51

35,52

35,53

PM10

24-hour

100

9

65

67

68

68

65

65

10th highest conc.

Annual

50

N.A.

27

28

29

28

27

28

N.A.

PM2.5

24-hour

50

18

36

36

39

39

36

36

19th highest conc.

24-hour

50

35

24

25

28

26

25

25

36th highest conc.

Annual

25

N.A.

15

16

17

16

16

16

N.A.

NO2

1-hour

200

18

98

108

118

92

105

118

19th highest conc.

Annual

40

N.A.

13

14

18

13

14

17

N.A.

SO2

10-min

500

3

60

79

82

57

76

79

4th highest conc.

24-hour

50

3

11

13

14

11

11

12

4th highest conc.

O3

8-hour

160

9

210

210

210

208

209

208

10th highest conc.

CO

1-hour

30,000

0

923

930

944

915

922

936

0

8-hour

10,000

0

840

845

852

835

840

848

0

Note:

[1] Bolded concentrations indicate exceedance of the air quality objectives

 

3.4                    Air Sensitive Receivers

3.4.1                 According to Annex 12 of EIAO-TM, any domestic premises, hotel, hostel, hospital, clinic, nursery, temporary housing accommodation, school, educational institution, office, factory, shop, shopping centre, place of public worship, library, court of law, sports stadium or performing arts centre shall be considered to be an Air Sensitive Receiver (ASR). Any other premises or place with which, in terms of duration or number of people affected, has a similar sensitivity to the air pollutants as above premises and places shall also be considered to be ASRs.

3.4.2                 The assessment area covers a distance of 500m of the Project boundary as per Clause 3.4.3.2 of the EIA Study Brief. Representative existing and planned ASRs around the Project site are selected to evaluate the potential air quality impact during construction and operation phases of the Project. The assessment areas for construction phase (including road improvement and utilities works) and operation phase are shown in Figure 3.1a and Figure 3.1b. The locations of the ASRs are shown in Figure 3.2 and details are summarized in Table 3.4.1 below and Appendix 3.1.


 

Table 3.4.1          Representative ASRs in the vicinity of the Project

ASR ID

Description

Land Use [1]

Approximate Horizontal Distance from the Project (m)

Assessment Height Above Ground (mAG)

Construction Phase

Operation Phase

 

Existing ASRs

 

AH11

Ching Ho Estate – Ching Chiu House

R

157

1.5-100

 

AH12

Ching Ho Estate – Ching Ping House

R

218

1.5-100

 

AH13

Ching Ho Estate – Ching Yu House

R

384

1.5-100

 

AH21

Cheung Lung Wai Estate – Ching Cheung House

R

22

1.5-100

 

AH22

Cheung Lung Wai Estate – King Cheung House

R

61

1.5-100

 

AH31

Tai Ping Estate – Tai Ping Kindergarden

R

357

1.5

 

AH32

Tai Ping Estate – Ping Hay House

R

356

1.5-75

 

AH41

Choi Yuen Estate – Choi Lai House

R

470

1.5-50

 

AH42

Choi Yuen Estate – Choi Wu House

R

464

1.5-75

 

AH51

Royal Green – Tower 3

R

307

1.5-100

 

AH61

Glorious Peak

R

461

1.5-100

 

AH71

8 Royal Green

R

496

1.5-100

 

AH81

Venice Garden – Block 2

R

480

1.5-75

 

AH91

Eden Manor – Tower 2

R

423

1.5-75

 

AL11

King’s Gate – B1

R

366

1.5-10

 

AL21

The Green

R

277

1.5-10

×

 

AL31

Residential R(C)2 (Land Lot 1909 in D.D. 100)

R

252

1.5-10

×

 

AV11

Ng Uk Tsuen

R

373

1.5-10

 

AV21

Chong Tsin Leng

R

286

1.5-10

 

AV31

Ping Kong Village

R

5

1.5-10

 

AV32

Ming Tak Court

R

19

1.5-10

 

AV33

Ping Kong Village

R

156

1.5-10

 

AV41

On Po Tsuen

R

44

1.5-10

 

AV51

Tai Lung

R

288

1.5-10

×

 

AV61

Lin Tong Mei Tsoi Yuen

R

152

1.5-10

×

 

AV71

Lin Tong Mei

R

38

1.5-10

×

 

AV72

Lin Tong Mei

R

320

1.5-10

×

 

AV81

Chan Uk Po

R

467

1.5-10

×

 

AV91

Tong Kung Leng

R

284

1.5-10

×

 

AW11

Catholic Diocese of Hong Kong Mother of Christ Church

W

324

1.5-15

 

AW21

Ping Kong Tin Hau Temple

W

170

1.5-5

 

AW31

Ebenezer Christian Church

W

154

1.5-5

×

 

AS11

TWGHs Ma Kam Chan Memorial Primary School

E

51

1.5-25

 

AS21

HHCKLA Buddhist Wisdom Primary School

E

34

1.5-25

 

AS31

Tsang Mui Millennium School

E

155

1.5-25

 

AS41

Elegantia College

E

48

1.5-25

 

AS42

Elegantia College

E

66

1.5-25

 

AM11

North District Hospital

G/IC

105

33.8[2]

 

AM12

North District Hospital

G/IC

98

33.8[2]

 

AM13

North District Hospital

G/IC

112

33.8[2]

 

AM14

North District Hospital

G/IC

128

33.8[2]

 

AM15

North District Hospital

G/IC

176

33.8[2]

 

AM16

North District Hospital

G/IC

186

33.8[2]

 

AM17

North District Hospital

G/IC

168

33.8[2]

 

AM21

Little Sisters of the Poor Saint Joseph’s Home for the Aged

G/IC

211

1.5-20

 

AM31

Buddhist Li Chong Yuet Ming Nursing Home for The Elderly

G/IC

320

1.5-25

 

AG11

The Hong Kong Golf Club

Rec

69

1.5-10

 

AG12

The Hong Kong Golf Club

Rec

25

1.5

 

AF11

Tai Lung Experiment Farm

G/IC

53

1.5-10

×

 

AF12

Tai Lung Experiment Farm

G/IC

173

1.5-10

×

 

AF21

Tai Lung Veterinary Laboratory

G/IC

5

1.5-10

×

 

AF31

Hong Kong Canine Working and Agility Club Limited

C

25

1.5-5

×

 

Planned ASRs

 

PH11

Proposed Public Housing at Ching Hiu Road

R

258

1.5-100

×

 

PH21

Proposed Public Housing at Tai Tau Leng

R

417

1.5-100

×

 

PL11

Proposed Residential (Land Lot 4076 in D.D. 91)

R

229

1.5-10

×

 

PM11

North District Hospital Expansion

G/IC

137

33.8[3]

×

 

PM12

North District Hospital Expansion

G/IC

112

33.8[3]

×

 

PM13

North District Hospital Expansion

G/IC

257

33.8[3]

×

 

Proposed Development ASRs

 

B011

Block 1

R

-

1.5 – 106

×

 

B012

Block 1

R

-

1.5 – 106

×

 

B013

Block 1

R

-

1.5 – 106

×

 

B014

Block 1

R

-

1.5 – 106

×

 

B021

Block 2

R

-

1.5 – 103.2

×

 

B022

Block 2

R

-

1.5 – 103.2

×

 

B023

Block 2

R

-

1.5 – 103.2

×

 

B024

Block 2

R

-

1.5 – 103.2

×

 

B031

Block 3

R

-

1.5 – 119.6

×

 

B032

Block 3

R

-

1.5 – 119.6

×

 

B033

Block 3

R

-

1.5 – 119.6

×

 

B034

Block 3

R

-

1.5 – 119.6

×

 

B041

Block 4

R

-

1.5 – 119.6

×

 

B042

Block 4

R

-

1.5 – 119.6

×

 

B043

Block 4

R

-

1.5 – 119.6

×

 

B051

Block 5

R

-

1.5 – 103.2

×

 

B052

Block 5

R

-

1.5 – 103.2

×

 

B053

Block 5

R

-

1.5 – 103.2

×

 

B054

Block 5

R

-

1.5 – 103.2

×

 

B061

Block 6

R

-

1.5 – 137.6

×

 

B062

Block 6

R

-

1.5 – 137.6

×

 

B063

Block 6

R

-

1.5 – 137.6

×

 

B064

Block 6

R

-

1.5 – 137.6

×

 

B071

Block 7

R

-

1.5 – 100.4

×

 

B072

Block 7

R

-

1.5 – 100.4

×

 

B073

Block 7

R

-

1.5 – 100.4

×

 

B074

Block 7

R

-

1.5 – 100.4

×

 

B081

Block 8

R

-

1.5 – 132.9

×

 

B082

Block 8

R

-

1.5 – 132.9

×

 

B083

Block 8

R

-

1.5 – 132.9

×

 

B084

Block 8

R

-

1.5 – 132.9

×

 

B091

Block 9

R

-

1.5 – 103.2

×

 

B092

Block 9

R

-

1.5 – 103.2

×

 

B093

Block 9

R

-

1.5 – 103.2

×

 

B094

Block 9

R

-

1.5 – 103.2

×

 

B101

Block 10

R

-

1.5 – 128.9

×

 

B102

Block 10

R

-

1.5 – 128.9

×

 

B103

Block 10

R

-

1.5 – 128.9

×

 

B104

Block 10

R

-

1.5 – 128.9

×

 

B111

Block 11

R

-

1.5 – 128.9

×

 

B112

Block 11

R

-

1.5 – 128.9

×

 

B113

Block 11

R

-

1.5 – 128.9

×

 

B114

Block 11

R

-

1.5 – 128.9

×

 

B121

Block 12

R

-

1.5 – 128.9

×

 

B122

Block 12

R

-

1.5 – 128.9

×

 

B123

Block 12

R

-

1.5 – 128.9

×

 

CF01

Community Facilities

Rec

-

15-39 [4]

×

 

CF02

Community Facilities

Rec

-

15-39 [4]

×

 

CF03

Community Facilities

Rec

-

15-39 [4]

×

 

CF04

Community Facilities

Rec

-

15-39 [4]

×

 

CF05

Community Facilities

Rec

-

15-39 [4]

×

 

CP01

Podium

Rec

-

15 [4]

×

 

CP02

Podium

Rec

-

15 [4]

×

 

CP03

Podium

Rec

-

15 [4]

×

 

CP04

Podium

Rec

-

21 [4]

×

 

CP05

Podium

Rec

-

21 [4]

×

 

CP06

Podium

Rec

-

21 [4]

×

 

CS01

Proposed School

E

-

1.5 - 25

×

 

CS02

Proposed School

E

-

1.5 - 25

×

 

CS03

Proposed School

E

-

1.5 - 25

×

 

CS04

Proposed School

E

-

1.5 - 25

×

 

CS05

Proposed School

E

-

1.5 - 25

×

 

CS06

Proposed School

E

-

1.5 - 25

×

 

PP01

Proposed Visiting Centre

Rec

-

1.5

×

 

PP02

Proposed Visiting Centre

Rec

-

1.5

×

 

PP03

Proposed Visiting Centre

Rec

-

1.5

×

 

PP04

Proposed Visiting Centre

Rec

-

1.5

×

 

Note:

[1] R - Residential; E - Education; G/IC - Government, Institution and Community; Rec – Recreational; C – Commercial; H – Hospital or Home for Aged; W – Place for Public Worship

[2] Fresh air intake level at North District Hospital.

[3] Assume the same as existing North District Hospital as no information was provided in this stage.

[4] Lowest level of the usage above ground level

3.5                    Identification of Environmental Impacts

Construction Phase

3.5.1                 The potential source of air quality impact arising from the Project construction will be fugitive dust during site clearance, site formation, piling works, utility works and road improvement works. Construction work activities including site clearance, site formation and earth works are classified as “notifiable” and “regulatory” work under the Air Pollution Control (Construction Dust) Regulation. Fugitive dust would be generated from the following two sources:

·       Heavy construction works including piling, excavation, loading / unloading of spoils and material handling, etc.;

·       Wind erosion of exposed open area.

3.5.2                 There will be junction improvement works at Po Kin Road/Ping Kong Road and minor road modification works at Ping Kong Road as mentioned in Section 2. Fugitive dust may be generated from work activities including excavation, handling of construction materials and minor wind erosion. The road works will be carried out by section with 50m in length and the area of work front will be approximately 500m2 at one time. The area of road works of each section is approximately 0.5% of the work area of Sub-Area 1 only. 1 hand-held breaker and excavator will be used for each section of the excavation works. Each section of works will take only about 3 -5 weeks to complete.

3.5.3                 Apart from the works above, there will be utilities works as described in Section 2 for the Project, i.e. waterworks, sewerage works and drainage works. The extent of excavation, unloading/loading of spoils, material handling and exposed site area to wind erosion for utility works are constructed in sections which each section is about 50m in length. The works and exposed areas for each sections of each type of utilities works would be about 250m2 at one time. The total area of each section of all type of utilities works at one time is approximately 0.25% of work area of Sub-Area 1 only. 1 hand-held breaker and excavator will be used for each section of works during excavation. Each section of works will take only about 3 -5 weeks to complete. The waterworks areas of each section will occupy about 3.0% of the total waterworks area. Sewerage and drainage works will be 4.1% and 7.5% of the total work areas respectively.

3.5.4                 There will be works at Sub-Area 2 to Sub-Area 4. Minor passive recreation facilities such as a small single storey visitor centre (at Sub-Area 2 only), sitting-out areas, children’s playgrounds and minor ancillary facilities to support the recreation activity and landscaping works such as planting and transplanting works that are compatible with existing habitats will be proposed within Sub-Area 2 and Sub-Area 3. No works would be carried out in Sub-Area 4. No site formation will be conducted within Sub-Areas 2 to 3. The depth for planting and transplanting will be about 1m to 2m only as the habitats of Sub-Area 2 to Sub-Area 4 will be preserved. There will be approximately 5 trees only to be planted in Sub-Areas 2 and 3 per day in average and no tree planting in Sub-Area 4. The actual land use will be further confirmed in detailed design stage subject to further investigation. The assessment area including the road improvement and utility works is shown in Figure 3.1a.

3.5.5                 The above works are considered to be short-term and localised fugitive dust impacts. In addition, these construction works will be well-controlled with the following dust suppression measures. Active work area of Sub-Area 1, sections of road improvement and utilities works will not be carried out concurrently or will be carried out separated as far as practicable. The impacts of these utilities works and works within Sub-Areas 1 to 4 are considered as limited.

·       Any excavated or stockpile of dusty material should be covered entirely by impervious sheeting or sprayed with water to maintain the entire surface wet and then removed or backfilled or reinstated where practicable within 24 hours of the excavation or unloading;

·       Any dusty materials remaining after a stockpile is removed should be wetted with water and cleared from the surface of roads;

·       A stockpile of dusty material should not be extended beyond the pedestrian barriers, fencing or traffic cones;

·       The load of dusty materials on a vehicle leaving a construction site should be covered entirely by impervious sheeting to ensure that the dusty materials do not leak from the vehicle;

·       Surfaces where any pneumatic or power-driven drilling, cutting, polishing or other mechanical breaking operation takes place should be sprayed with water or a dust suppression chemical continuously;

·       Any skip hoist for material transport should be totally enclosed by impervious sheeting;

·       Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides;

·       Machinery and dusty activities (e.g. stockpiling areas) are located away from ASRs as far as possible;

·       Construction machinery should be maintained regularly so as to ensure no deterioration on the emission performance;

·       Solid screens or barriers should be erected around dusty activities;

·       The use of diesel or petrol powered generators should be avoided and mains electricity or battery powered equipment should be adopted where practicable;

·       Inactive exposed earth areas should be properly treated by compaction or sealing with latex, vinyl or other suitable impermeable sheeting.

3.5.6                 The construction works to be considered in the quantitative construction dust impact assessment are site clearance and site formation works in Sub-Area 1 area which the assessment area for quantitative assessment is shown in Figure 3.2a.

3.5.7                 On-site diesel-powered engines are potential sources of gaseous emissions of pollutants such as CO, PM, NO2 and SO2. The Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation comes into effects to control the emissions from diesel powered engines and limited amount of diesel powered mechanical equipment will be used on-site during construction phase. According to the Air Pollution Control (Fuel Restriction) Regulations, liquid fuel with a sulphur content of less than 0.005% by weight should be used. Under the effects of the above 2 regulations, the Air Pollution Control (Smoke) Regulation and the limited number of engines and operation hours, emissions of gaseous pollutants, e.g. CO, PM, NO2 and SO2 from the operation of on-site diesel powered mechanical equipment is considered to be limited.

3.5.8                 The temporary dust nuisance, measurable as TSP, PM10 and PM2.5, would be generated as a result of construction activities during site clearance, site formation and earth works. Particulate matters (TSP, PM10 and PM2.5) would be the pollutants to be concerned during the construction phase. The impacts are quantitatively assessed.

3.5.9                 The tentative construction programme as provided by the project engineer for site clearance and formation works of the site are between January 2024 and September 2025. The construction work periods were assumed to be Monday to Saturday and 12 hours of work from 7am to 7pm. The programme is presented in Appendix 3.2.

3.5.10              There are a few concurrent projects identified within the assessment area which may have cumulative impacts. The information of the concurrent projects is mentioned in Section 1 and Table 3.5.1 below shows the distance of the potential concurrent works. The locations of the works are shown in Figure 1.2.

Table 3.5.1          Summary of Potential Concurrent Projects for Construction Dust Impact

Potential Concurrent Projects

Tentative Construction Commencement Year

Target Operation/ Target Completion of Development

Approx. Horizontal Distance from Project Boundary (m)

Potential Housing Developments in North District - Ching Hiu Road

2022

2030

380

Potential Housing Developments in North District - Tai Tau Leng

2025

2032

480

North District Hospital Expansion

2021

2030

85

Drainage Improvements at North District

2021

2027

290 (SE of Project) / 310 (S of Project)

Fanling Highway Widening

2024

2031

450

Po Shek Wu Flyover

2024

2029

470

Road Improvement Works at Fan Kam Road

Not Available

Not Available

100

Fanling Area 36 Phase 4 (Ching Ho Extension)

2020

2024

480

Private Housing Development at Lot 4076 in D.D. 91

Not Available

2028

295

Reclaimed Water Supply to Sheung Shui and Fanling – Investigation, Design and Construction

2020

2025

845

Sheung Shui Lot 2RP in DD 92, Sheung Shui

Not Available

2023

519

So Kwun Po Interchange

2025

2030

587

Retrofitting of Noise Barriers on Po Shek Wu Road

2024

2028

1700

 

3.5.11              As shown in Figure 1.2, the scale of drainage improvements at North District works are small which the site boundaries of the woks are about 80m in length (approx. 0.8% of Sub-Area 1 area which assumes 10m wide of the work area) and 130m in length (approx. 1.3% of Sub-Area 1 area which assumes 10m wide of the work area). The works are about 300m away from the Project boundary and considered with dust control measures to be implemented, the dust impact from the drainage improvements are anticipated to be limited.

3.5.12              According to the Preliminary Environmental Review (PER) of the road improvement works at Fan Kam Road, the excavation work will only be carried out a few meters from the existing road which excavated material is limited. With implementation of dust reduction measures, the construction dust impact of the road improvement works at Fan Kam Road is considered as limited and is not included in the quantitative assessment.

3.5.13              The target completion year of the Fanling Area 36 Phase 4 is 2024. According to the site visit on Dec 2020, the Fanling Area 36 Phase 4 site were on superstructure stage, hence works of this project in Year 2024 would be small scale and minor works only, e.g. interior works. The dust impact is also considered as limited and not included in the assessment.

3.5.14              The Reclaimed Water Supply to Sheung Shui and Fanling, Sheung Shui Lot 2RP in DD 92 and So Kwun Po Interchange are more than 500m away of the Project boundary which the concurrent dust impact of these projects are considered as limited and excluded from the quantitative assessment.

3.5.15              The rest of co-current works are included in the quantitative assessment which are shown in Appendix 3.2.

Operation Phase

3.5.16              The major pollutant sources during operation phase of the Project are as below.

·       Vehicular emissions from road networks within the assessment area;

·       Chimney emissions from North District Hospital;

·       Public Transport Interchanges (PTIs) of the Project, Ching Ho Estate and Tai Ping Estate; and

·       Background pollutant concentrations.

3.5.17              The locations of chimneys and PTIs are shown in Figure 3.3. Vehicular emissions arising from the concurrent projects due to planned road network or induced traffic, including Fanling Highway widening, Po Shek Wu Flyover, planned housing sites in the vicinity of the Project, Tai Tau Leng etc. as Table 3.5.1 that would have cumulative air quality impact on nearby ASRs have also been addressed. There are 2 major chimney emission sources more than 500m but within 4km from project boundary which are Wo Hop Shek Crematorium, Asphalt Plant in Sheung Shui. However, hills and numbers of high rise buildings are between the two sources and the project site which most pollutants are blocked by these structures. Hence, these 2 major sources shall not cause direct impact on the identified ASRs and their impacts have been accounted in the background air pollutants concentrations produced by the PATH model.

Identification of Representative Air Pollutants of Vehicle Emissions

3.5.18              The air quality pollutant source during the operational phase of the project would be the emission from the travelling vehicles. The tailpipe emission comprises a number of pollutants, including Nitrogen Oxides (NOX), PM10, PM2.5, SO2, CO, O3, Toxic Air Pollutants (TAPs), Lead (Pb) etc. Determination of representative air pollutants for this Project is discussed as below.

3.5.19              NOx is a major pollutant from fossil fuel combustion. According to the 2019 Hong Kong Emission Inventory Report published by EPD which is the latest available information at the time of preparing this report, navigation and public electricity generation are the largest NOx emission sources and accounted for 35% and 30% of the total emission in 2019, respectively. NOx emission from vehicles was the 3rd largest, accounting for 16% of the total. NOx would be converted to NO2 in the presence of O3 and Volatile Organic Compounds (VOCs). Increasing of traffic flows would increase the roadside NO2 concentration. Therefore, NO2 is one of the representative air pollutants for the operation phase of the Project.

3.5.20              PM10 and PM2.5 refer to suspended particulates with nominal diameter of 10µm or less and 2.5µm or less respectively. Both particulate matters are considered as key pollutants of increasing of traffic flows of the Project as the vehicular emissions contribute 9% of PM10 and 11% of PM2.5 of the total emissions in 2019.

3.5.21              SO2 from road traffic emission contribute less than 1% of the total emissions in 2019 and ultra-low sulphur fuel is used for all types of vehicle in Hong Kong. Hence, SO2 would not be a critical air pollutant of concern.

3.5.22              CO from vehicular emissions contribute about 50% of the total emissions in 2019. According to Air Quality in Hong Kong 2020 published by EPD which is the latest available information at the time of preparing this report, the highest 1-hour average (2,850 µg/m3) and 8-hour average (1,685 µg/m3) were recorded at Causeway Bay roadside station which were 9.5% and 16.85% of the respective AQOs. These concentrations are well below the AQOs so CO is not considered as critical pollutant.

3.5.23              O3 is produced from photochemical reaction between NOx and VOCs in the presence of sunlight, which will not be generated by this Project. Concentration of O3 is governed by both precursors, atmospheric transport from other areas and meteorological factors. the formation of O3 generally takes hours to proceed and O3 measured locally could be attributed to emissions generated from places over long distances. This explains why higher ozone levels are generally not produced in the urban core or industrial area but rather at some distance downwind after photochemical reactions have taken place. The increase of NOx emission in the roadside environment, O3 reacts with NO to give NO2 and thus results in decrease of O3. O3 is therefore not considered as a key air pollutant.

3.5.24              TAPs are pollutants found in vehicular exhaust. With reference to EPD’s Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report, monitored TAPs in Hong Kong include diesel particulate matters (DPM), toxic elemental species, dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), carbonyls, and volatile organic compounds (VOCs). According to the results of the report and Sources of PCB emissions by European Monitoring and Evaluation Programme (EMEP) / Core Inventory Air Emissions (Corinair), vehicular emission is not considered as primary source of dioxins, PCBs, carbonyls and most toxic elemental species in Hong Kong. Therefore, these pollutants are not considered as key pollutants for the operation phase of the Project.

3.5.25              DPM from local vehicular emission is one of major sources of the pollutant. EPD is preparing the new initiatives to further reduce emission from diesel vehicles which the diesel particulate level would also be reduced since Initiatives in 2017. As recommended by EPD’s Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report, elemental carbon (EC) is used as a surrogate for DPM, and with reference to Chemical Separation of PM2.5 Filter Samples 2019, EC showed a significant decrease in concentration from 2015 to 2019 in Hong Kong, i.e. -27.9%, -40.2%, -24.1% and -41.4% at Mong Kok, Tsuen Wan, Yuen Long and Kwai Chung Monitoring Sites, respectively. With the continual efforts by EPD to reduce particulate emission from the vehicular fleet, a discernible decreasing trend is noted in the level of particulate matter. Therefore, DPM is not selected as representative pollutant for the Project.

3.5.26              PAHs from local vehicular traffic is also an important source of PAHs. The most important PAH is Benzo[a]pyrene, and it is often selected as a marker for the PAHs. The EU Air Quality Standards for PAHs (expressed as concentration of Benzo[a]pyrene) is 1 ng/m3 for annual average. With reference to “Air Quality in Hong Kong 2020”, annual average concentrations of Benzo[a]pyrene measured at EPD’s Tsuen Wan and Central/Western stations were 0.05 ng/m3 and 0.03 ng/m3, respectively, which is far below the EU Standards. Hence, PAHs are not considered as key pollutants for the Project.

3.5.27              VOCs are of great concern of health and environmental problems from vehicular emission. According to Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report, 2003, among the VOC compounds, benzene and 1,3-butadiene are the most significant ones for Hong Kong. The UK National Air Quality Objectives for benzene and 1,3-butadiene are 5 µg/m3 and 2.25 µg/m3 respectively. With reference to “Air Quality in Hong Kong 2020”, annual average concentrations of benzene at EPD’s monitoring stations at Tsuen Wan and Central/Western were 1.65 µg/m3 and 0.9 µg/m3, respectively. The levels of 1,3-butadiene were 0.04 µg/m3 and 0.04 µg/m3 for Tsuen Wan and Central/Western stations respectively. The concentrations are far below the UK AQOs. Thus, VOCs are not considered as key pollutants for quantitative assessment for this project.

3.5.28              Pb is no key pollutant to be concerned for this assessment. According to the “Air Quality in Hong Kong 2020”, the annual average concentrations measures at Tsuen Wan and Central/Western stations are 9 ng/m3 and 8 ng/m3, respectively. The measured concentrations were well below the AQO limits of 500 ng/m3.

Identification of Representative Air Pollutants of Chimneys Emissions

3.5.29              The fuel used by nearby chimneys emissions are towngas which is extremely low in sulphur content . Therefore, the concerned pollutants during operation phase are NO2 and PM10, PM2.5.

Identification of Odour Impact

3.5.30              No new sewerage treatment works (STW) and sewage pumping station (SPS) will be proposed in the Project. Sewage generated in the Project will be discharged to public sewerage system. No odour impact of sewage generated from the Project is anticipated. Refuse Collection Points (RCPs) is proposed for the Project but the locations and design are not available at this stage and will be studied in the Investigation, Design and Construction (IDC) stage. The proposed RCPs will be located from ASRs as far as possible. Proper ventilation, exhaust and deodourisation system will be provided to minimize the odour impact upon nearby ASRs. Good hygiene of the RCPs will be enhanced through frequent washing, proper covering of refuse bins, closing of roller shutters, good housekeeping and proper maintenance of ventilation, exhaust and deodorisation system. The potential impact of adverse odour from proposed RCPs on nearby ASRs is not anticipated.

3.6                    Construction Phase Assessment Methodology

Dust Emission associated with the Project and other Sources

3.6.1                 The emission factors for different dust generating activities are based on the 5th edition of Compilation of Air Pollution Emission Factors (AP-42) issued by United States Environmental Protection Agency (USEPA). The emission factors for the construction dust sources are summarised in Table 3.6.1 below and the details of calculation and location of dust sources are presented in Appendix 3.2.


 

Table 3.6.1  Emission Factors for Construction Dust Impact Assessment

Source

Activities

Emission Factors

All construction sites

Heavy construction activities including land clearance, ground excavation, cut and fill operations, construction of the facilities, haul road, etc.

TSP = 2.69 Mg/hectare/month = 2.08 x 10-4 g/m2/s

PM10 = 9.82 x 10-5 g/m2/s

PM2.5 = 1.49 x 10-5 g/m2/s

Wind erosion

TSP = 0.85 Mg/hectare/year =     2.70 x 10-6 g/m2/s

PM10 = 1.27 x 10-6 g/m2/s

PM2.5 = 1.94 x 10-7 g/m2/s

3.6.2                 The work areas for site clearance and formation of Sub-Area 1 of the Project are divided into two areas (A and B) as shown in Appendix 3.2. Based on the programme, Year 2024 is selected as site clearance and formation will last for a whole complete year. As advised by project engineer, construction traffic to be generated is very similar throughout the whole construction period. Year 2029 is the year with the highest traffic flows in the assessment area. Cumulative impacts of dust emissions from construction works of the Project and concurrent projects as Section 3.5.15 are conducted quantitatively in this assessment.

3.6.3                 Approach for prediction of particulate emissions from roads are the same as operational phase assessment as described in Section 3.8, in which the dispersion model, CALINE4 is used to assess the vehicular emission impact.

3.6.4                 The EMFAC-HK model (version 4.3) issued by EPD was employed to estimate the particulate emission inventory of vehicles from open road. The methodology and assumptions of the emission inventory model are the same as operational phase assessment as Section 3.8 and the emission factors are summarised in Appendix 3.8. For conservative approach, the highest traffic flows in Year 2029 and highest emission Year 2024 are adopted.

3.6.5                 For chimney and PTI emissions as described in Section 3.5.16, the prediction approach is the same as the operational air quality assessment as described in Section 3.8, in which the dispersion model, AERMOD, is used to assess the chimney and PTI emission impacts.

3.6.6                 Hourly pollutant concentration data predicted by PATH for Year 2025 provided by EPD are directly adopted as the background concentration. As TSP concentrations are not available in the PATH model, it is considered reasonable to assume the hourly PM10 concentrations from PATH as the ambient TSP background concentrations, since the particulates of sizes larger than 10μm generated from far-field dust sources would have been largely settled before reaching the ASRs, and hence most of the particulates contributed from far-field sources affecting the ASRs will likely be of less than or equal to 10μm in size (i.e. PM10).

Methodology and Assumptions of Dispersion Model – Construction Activities

Dispersion Model

3.6.7                 The construction dust emissions were modelled by using a steady-state plume model, AERMOD which was developed by the American Meteorological Society/Environmental Protection Agency Regulatory Model Improvement Committee (AERMIC). The model is accepted by EPD with reference to “Guidelines on Choices of Models and Model Parameters”.

Meteorological Data

3.6.8                 WRF meteorological data extracted from the PATH model at the grid, (34,51), (35,52) and (35,53) are employed. Mixing heights that are higher than the maximum and lower than the minimum mixing heights (1941m and 131m) measured at King’s Park station in 2015 were replaced with the maximum and minimum mixing height of the King’s Park station. The minimum wind speed was capped at 1m/s for the treatment of clam hours.

3.6.9                 The data was then processed by the AERMET model. Details of the surface characteristics parameters of the proposed site and the surrounding (i.e. surface roughness, albedo and Bowen ratio) are presented in Appendix 3.9.

Model Approach

3.6.10              Dry depletion option was selected for the modelling of the deposition of particle. The particle size distribution as shown in Table 3.6.2 below was estimated based on S13.2.4.3 of USEPA AP-42 which was employed in the model assessment. The particle density, 2.5g/cm3, with reference to “Update of Fugitive Dust Emission Factors in AP-42 Section 11.2” (EPA Contract No. 68-02-3891, 1987) was adopted in the assessment.

Table 3.6.2  Particle Size Distribution

Particle Size, µg

Average Particle Size, µg

TSP Distribution

PM10 Distribution

PM2.5 Distribution

15 – 30

22.5

35%

--

--

10 – 15

12.5

18%

--

--

5 – 10

7.5

20%

43%

--

2.5 – 5

3.75

20%

42%

--

0 – 2.5

1.25

7%

15%

100%

3.6.11              The landuse circumscribed by a 3km radius circle centered at the emission sources consist of more than 50% of built-up area, according to AERMOD implementation Guide, urban  dispersion option was selected for the model. The population of North District was employed and the default urban roughnesswere adopted in the model.

3.6.12              For both unmitigated and mitigated scenarios, 100% of active construction work area for the Site was assumed for long-term and short-term assessment as conservative approach.

3.6.13              No site hoarding is assumed for the unmitigated scenario. Site hoarding will be erected along the construction site boundary to minimise the construction dust impact that the dust release height with hoarding erected was assumed to be 3m above ground for mitigated scenario.

3.6.14              There is no information of detail construction activities and assessment available for the concurrent projects so 100% active construction work areas were employed in the assessment. Dust control measures as 2.4m site hoarding and water suppression as recommended in the Air Pollution Control (Construction Dust) regulation was assumed for the concurrent projects. Dust suppression rate at 91.7% as approved EIAs, Development at San Hing Road and Hong Po Road, Tuen Mun (EIA-263/2020) and Shuen Wan Golf Course (EIA-260/2019) was assumed for the concurrent projects in the assessment.

3.7                    Construction Assessment Results

Unmitigated Scenario

3.7.1                 The predicted TSP, PM10 and PM2.5 impact at the worst affected level arising from unmitigated construction activities are summarised in Table 3.7.1, Table 3.7.2 and Table 3.7.3. Details of predicted concentrations are shown in Appendix 3.3.

Table 3.7.1          Predicted TSP Concentration at Worst Affected Level of ASRs – Unmitigated Scenario

ASRs

Worst Affected Height, mAG

TSP Concentrations (µg/m3)

Highest Hourly Averaged

AH11

10.0

1537.9

AH12

10.0

1575.7

AH13

15.0

1145.3

AH21

1.5

4158.6

AH22

5.0

2947.6

AH31

1.5

946.7

AH32

15.0

1148.3

AH41

15.0

1116.0

AH42

20.0

1365.1

AH51

15.0

1240.1

AH61

15.0

981.1

AH71

15.0

912.1

AH81

20.0

820.5

AH91

20.0

783.9

AL11

1.5

651.7

AV11

10.0

1096.1

AV21

10.0

1227.3

AV31

10.0

2323.6

AV32

1.5

2815.7

AV33

10.0

1594.1

AV41

10.0

1544.3

AW11

15.0

1330.7

AW21

5.0

1296.7

AS11

5.0

3137.4

AS21

5.0

3198.7

AS31

10.0

1876.5

AS41

5.0

2490.8

AS42

5.0

2176.2

AM11

33.8

533.0

AM12

33.8

551.2

AM13

33.8

543.8

AM14

33.8

523.1

AM15

33.8

459.2

AM16

33.8

399.4

AM17

33.8

428.7

AM21

10.0

1631.4

AM31

15.0

1212.6

AG11

5.0

2326.3

AG12

1.5

3283.1

Standard

500

Note: Concentrations exceed the standard are shown in in red and bold

 

 

 


 

Table 3.7.2          Predicted PM10 Concentration at Worst Affected Level of ASRs – Unmitigated Scenario

ASRs

Worst Affected Height, mAG

PM10 Concentrations (µg/m3)

10th Highest Daily Averaged

Annual Averaged

10th Highest Daily Averaged

Annual Averaged

AH11

1.5

1.5

74.5

32.2

AH12

1.5

1.5

75.3

32.1

AH13

1.5

1.5

71.9

29.9

AH21

1.5

1.5

250.1

84.1

AH22

1.5

1.5

160.6

58.5

AH31

1.5

1.5

67.5

33.7

AH32

15.0

1.5

70.1

33.8

AH41

1.5

1.5

73.8

33.4

AH42

15.0

1.5

73.5

32.9

AH51

1.5

1.5

78.1

34.4

AH61

1.5

1.5

71.7

30.5

AH71

1.5

1.5

71.2

30.0

AH81

1.5

1.5

65.6

31.8

AH91

1.5

1.5

76.1

33.5

AL11

1.5

1.5

72.6

33.0

AV11

1.5

1.5

68.9

31.7

AV21

1.5

1.5

71.2

29.1

AV31

1.5

1.5

103.9

37.4

AV32

1.5

1.5

102.1

38.0

AV33

1.5

1.5

83.7

31.3

AV41

10.0

5.0

84.6

32.3

AW11

1.5

1.5

87.6

42.9

AW21

1.5

1.5

78.5

30.3

AS11

1.5

1.5

166.5

59.6

AS21

1.5

1.5

156.6

53.2

AS31

1.5

1.5

77.7

34.4

AS41

1.5

1.5

99.5

35.7

AS42

1.5

1.5

96.0

36.4

AM11

33.8

33.8

69.6

34.1

AM12

33.8

33.8

71.5

34.4

AM13

33.8

33.8

70.9

34.1

AM14

33.8

33.8

68.8

33.7

AM15

33.8

33.8

65.6

32.5

AM16

33.8

33.8

66.4

33.5

AM17

33.8

33.8

66.8

33.9

AM21

1.5

1.5

85.3

37.8

AM31

1.5

1.5

78.0

39.5

AG11

1.5

1.5

165.3

66.7

AG12

1.5

1.5

295.8

118.6

Standard

100

50

Note: Concentrations exceed the standard are shown in in red and bold

 

Table 3.7.3          Predicted PM2.5 Concentration at Worst Affected Level of ASRs – Unmitigated Scenario

ASRs

Worst Affected Height, mAG

PM2.5 Concentrations (µg/m3)

36th Highest Daily Averaged Conc. 

19th Highest Daily Averaged Conc.

Annual Averaged Conc.

36th Highest Daily Averaged Conc. 

19th Highest Daily Averaged Conc.

Annual Averaged Conc.

AH11

5.0

1.5

1.5

25.8

38.4

16.5

AH12

1.5

1.5

1.5

25.9

38.4

16.5

AH13

1.5

10.0

1.5

25.8

36.8

16.1

AH21

1.5

1.5

1.5

43.3

49.7

25.6

AH22

1.5

1.5

1.5

31.4

42.1

21.3

AH31

1.5

1.5

1.5

26.1

36.0

17.2

AH32

1.5

1.5

1.5

25.9

35.8

17.2

AH41

1.5

1.5

1.5

26.2

35.9

17.3

AH42

1.5

1.5

1.5

26.0

35.9

17.1

AH51

1.5

1.5

1.5

26.5

38.2

17.2

AH61

1.5

1.5

1.5

25.9

36.4

16.5

AH71

1.5

1.5

1.5

25.3

36.0

16.2

AH81

1.5

1.5

1.5

25.7

35.7

16.8

AH91

1.5

1.5

1.5

27.0

37.8

17.1

AL11

1.5

1.5

1.5

26.6

37.5

16.9

AV11

1.5

1.5

1.5

25.3

36.2

16.5

AV21

1.5

1.5

1.5

25.2

36.0

15.9

AV31

1.5

1.5

1.5

29.4

41.4

17.4

AV32

1.5

1.5

1.5

28.3

39.2

17.4

AV33

1.5

1.5

1.5

26.7

36.2

16.3

AV41

5.0

10.0

1.5

27.5

39.3

16.5

AW11

1.5

1.5

1.5

27.1

36.2

18.6

AW21

1.5

1.5

1.5

26.7

36.2

16.1

AS11

1.5

1.5

1.5

32.5

42.6

21.4

AS21

1.5

1.5

1.5

30.8

42.7

20.3

AS31

1.5

1.5

1.5

26.0

38.5

17.0

AS41

1.5

1.5

1.5

26.8

39.4

17.1

AS42

1.5

1.5

1.5

26.9

38.9

17.3

AM11

33.8

33.8

33.8

25.3

36.1

16.8

AM12

33.8

33.8

33.8

25.3

36.1

16.8

AM13

33.8

33.8

33.8

25.3

36.1

16.8

AM14

33.8

33.8

33.8

25.3

36.1

16.7

AM15

33.8

33.8

33.8

25.3

36.1

16.5

AM16

33.8

33.8

33.8

25.9

35.7

16.8

AM17

33.8

33.8

33.8

26.0

35.7

16.9

AM21

1.5

1.5

1.5

27.1

38.0

17.6

AM31

1.5

1.5

1.5

26.7

36.0

18.1

AG11

1.5

1.5

1.5

37.1

46.6

22.8

AG12

1.5

1.5

1.5

55.9

65.5

32.2

Standard

50

50[1]

25

Note: Concentrations exceed the standard are shown in in red and bold

[1] For new government project

3.7.2                 Exceedances of TSP standard were predicted amongst most of the representative ASRs. Annual averaged and daily averaged PM10 and PM2.5 objectives are exceeded at numbers of ASRs.

Recommended Mitigation Measures

3.7.3                 To reduce the dust emission from the Project and achieve compliances of relevant criteria at ASRs, regular watering under a good site practice should be adopted. In accordance with the “Control of Open Fugitive Dust Sources” (USEPA AP-42), watering once per hour on exposed worksites and haul road is proposed to achieve dust removal efficiency of 91.7%. These dust suppression efficiencies are derived as presented in Appendix 3.2. Any potential dust impact and watering mitigation would be subject to the actual site conditions. While the above watering frequencies are to be followed, the extent of watering may vary depending on actual site conditions. The dust levels would be monitored and managed under an Environmental Monitoring and Audit (EM&A) programme as specified in the EM&A Manual. In addition, dust control measures as recommended in the Air Pollution Control (Construction Dust) Regulation, where applicable, should be implemented. Recommended control measures are shown as below.

·       The works area for site clearance shall be sprayed with water throughout the operation to maintain the entire surface wet (e.g. installation of sprinklers);

·       Restricting heights from which materials are to be dropped, as far as practicable to minimise the fugitive dust arising from unloading/ loading;

·       All vehicles shall be washed to remove any dusty materials from its body and wheels before leaving a construction site;

·       All spraying of materials and surfaces should avoid excessive water usage;

·       When a vehicle leaving a construction site is carrying a load of dusty materials, the load shall be covered entirely by clean impervious sheeting;

·       Travelling speeds should be controlled to reduce traffic induced dust dispersion and re-suspension within the Site from the operating trucks;

·       Any stockpile of dusty materials shall be covered entirely by impervious sheeting; and/or placed in an area sheltered on the top and 4 sides;

·       All dusty materials shall be sprayed with water immediately prior to any loading, unloading or transfer operation so as to maintain the dusty materials wet;

·       Deploy NRMMs as far as practicable;

·       Exempted NRMMs are not allowed;

·       Hoarding of not less than 3m high from ground level shall be erected along the the Site boundary except for a site entrance or exit;

·       Compaction, turfing, hydroseeding, vegetation planting or sealing with latex, vinyl, bitumen, shortcrete or other suitable surface stabiliser shall be provided within six months after the last construction activity on the construction site or part of the construction site where the exposed earth lies; and,

·       Avoid concurrent dusty construction works near ASRs through the control of timing and locations of different construction activities.

Mitigated Scenario

3.7.4                 The predicted TSP, PM10 and PM2.5 impact at the worst affected level arising from construction activities with implementation of mitigated measures are summarised in Table 3.7.4, Table 3.7.5 and Table 3.7.6. Details of predicted concentrations are shown in Appendix 3.3. Contours of particulate matters at ground level (1.5mAG) as the worst impact level are presented in Figures 3.5a-f.

Table 3.7.4          Predicted TSP Concentration at Worst Affected Level of ASRs – Mitigated Scenario

ASRs

Worst Affected Height, mAG

TSP Concentrations (µg/m3)

Highest Hourly Average

AH11

1.5

194.5

AH12

1.5

194.6

AH13

1.5

192.5

AH21

1.5

359.7

AH22

1.5

264.2

AH31

1.5

194.9

AH32

15.0

195.5

AH41

15.0

321.7

AH42

15.0

341.1

AH51

1.5

244.9

AH61

1.5

189.3

AH71

1.5

189.0

AH81

15.0

194.0

AH91

10.0

203.5

AL11

1.5

197.7

AV11

10.0

191.9

AV21

1.5

192.4

AV31

10.0

239.1

AV32

1.5

305.9

AV33

1.5

199.9

AV41

10.0

194.7

AW11

1.5

444.1

AW21

1.5

196.0

AS11

1.5

283.6

AS21

1.5

280.5

AS31

1.5

194.5

AS41

1.5

252.6

AS42

5.0

212.9

AM11

33.8

203.2

AM12

33.8

201.4

AM13

33.8

201.4

AM14

33.8

202.5

AM15

33.8

204.2

AM16

33.8

207.0

AM17

33.8

208.1

AM21

10.0

197.1

AM31

1.5

332.4

AG11

5.0

253.3

AG12

1.5

322.8

Standard

500

 

Table 3.7.5          Predicted PM10 Concentration at Worst Affected Level of ASRs – Mitigated Scenario

ASRs

Worst Affected Height, mAG

PM10 Concentrations (µg/m3)

10th Highest Daily Average

Annual Average

10th Highest Daily Average

Annual Average

AH11

5.0

1.5

66.5

28.3

AH12

1.5

1.5

67.1

28.4

AH13

1.5

1.5

65.1

27.9

AH21

1.5

1.5

70.6

35.4

AH22

1.5

1.5

68.3

32.3

AH31

1.5

1.5

65.9

29.7

AH32

1.5

1.5

65.8

29.7

AH41

1.5

1.5

65.5

30.9

AH42

1.5

1.5

65.6

30.6

AH51

1.5

1.5

71.5

31.0

AH61

1.5

1.5

64.8

28.5

AH71

1.5

1.5

64.7

28.1

AH81

1.5

1.5

65.6

29.2

AH91

1.5

1.5

76.1

32.2

AL11

1.5

1.5

72.6

31.2

AV11

1.5

1.5

65.3

28.5

AV21

1.5

1.5

65.2

27.7

AV31

1.5

1.5

73.3

29.1

AV32

1.5

1.5

68.8

28.9

AV33

1.5

1.5

69.1

28.1

AV41

5.0

5.0

72.6

28.2

AW11

1.5

1.5

72.4

38.4

AW21

1.5

1.5

68.6

27.9

AS11

1.5

1.5

68.0

32.3

AS21

1.5

1.5

67.8

31.3

AS31

5.0

1.5

67.6

28.8

AS41

1.5

1.5

67.4

28.8

AS42

1.5

1.5

67.3

29.0

AM11

33.8

33.8

66.4

28.1

AM12

33.8

33.8

66.2

28.1

AM13

33.8

33.8

65.9

28.1

AM14

33.8

33.8

65.8

28.0

AM15

33.8

33.8

65.6

27.9

AM16

33.8

33.8

66.4

28.6

AM17

33.8

33.8

66.6

28.6

AM21

1.5

1.5

66.9

30.3

AM31

1.5

1.5

67.3

34.8

AG11

1.5

1.5

74.5

33.6

AG12

1.5

1.5

84.2

39.6

Standard

100

50

 


 

Table 3.7.6          Predicted PM2.5 Concentration at Worst Affected Level of ASRs – Mitigated Scenario

ASRs

Worst Affected Height, mAG

PM2.5 Concentrations (µg/m3)

36th Highest Daily Average Conc. 

19th Highest Daily Average Conc.

Annual Average Conc.

36th Highest Daily Average Conc. 

19th Highest Daily Average Conc.

Annual Average Conc.

AH11

1.5

1.5

5.0

25.2

36.1

15.9

AH12

1.5

1.5

1.5

25.3

36.2

15.9

AH13

1.5

1.5

1.5

25.2

36.1

15.8

AH21

1.5

1.5

1.5