4                                AIR QUALITY IMPACT

4.1                         Introduction

This section presents the assessment findings of the potential air quality impacts on air sensitive uses arising from the construction and operation of the proposed CKR. Mitigation measures for construction activities have been recommended and potential environmental impacts associated with construction dust would be controlled to acceptable levels. Assessment results have concluded that the predicted cumulative air quality impacts on all sensitive receivers would comply with the Air Quality Objectives during the operational phase of the Project.

4.2                         Legislation and Standards

The air quality impact assessment criteria shall make reference to the Hong Kong Planning Standards and Guidelines (HKPSG), the Air Pollution Control Ordinance (APCO) (Cap.311), and Annex 4 of the Technical Memorandum on Environmental Impact Assessment Process (TM-EIAO).

The APCO (Cap.311) provides the power for controlling air pollutants from a variety of stationary and mobile sources and encompasses a number of Air Quality Objectives (AQOs). In addition to the APCO, the following overall policy objectives are laid down in Chapter 9 of the Hong Kong Planning Standards and Guidelines (HKPSG):

·         Limit the contamination of the air in Hong Kong, through land use planning and through the enforcement of the APCO to safeguard the health and well-being of the community; and

·         Ensure that the AQO for 7 common air pollutants are met as soon as possible.

Currently, the AQOs stipulate limits on concentrations for 7 pollutants including sulphur dioxide (SO2), Total Suspended Particulates (TSP), Respirable Suspended Particulates (RSP), Nitrogen Dioxide (NO2), Carbon Monoxide (CO), photochemical oxidants, and Lead (Pb).  The AQOs are listed in the table below.

Table 4.1: Hong Kong Air Quality Objectives (HKAQO)

Pollutant

Limits on Concentration, μg/m3 [1]

(ppm in brackets)

1-hr [2]

8-hr [3]

24-hr [3]

3-Month [4]

Annual [4]

Sulphur Dioxide

800

(0.3)

 

350

(0.13)

 

80

(0.03)

Total Suspended Particulates

500 [7]

 

260

 

80

Respirable Suspended Particulates [5]

 

 

180

 

55

Carbon Monoxide

30,000

(26.2)

10,000

(8.7)

 

 

 

Nitrogen Dioxide

300

(0.16)

 

150

(0.08)

 

80

(0.04)

Photochemical Oxidants (as ozone) [6]

240

 

 

 

 

Lead

 

 

 

1.5

 

Notes:

[1]   Measured at 298K and 101.325 kPa.

[2]   Not to be exceeded more than three times per year.

[3]   Not to be exceeded more than once per year.

[4]   Arithmetic mean.

[5]   Respirable suspended particulates means suspended particulates in air with a nominal aerodynamic diameter of 10 micrometres or smaller.

[6]   Photochemical oxidants are determined by measurement of ozone only.

[7]   Not an AQO but is a criterion for evaluating air quality impacts as stated in Annex 4 of TM-EIAO.

 

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

 

The Practice Note on Control of Air Pollution in Vehicle Tunnel published by EPD provides guidelines on control of air pollution in vehicle tunnel. Guideline values on tunnel air quality are shown in the following table.

Table 4.2: Tunnel Air Quality Guidelines

Pollutant

Average Time

Maximum Concentration

µg/m3 [1]

ppm

Carbon Monoxide, CO

5 minutes

115,000

100

Nitrogen Dioxide, NO2

5 minutes

1,800

1

Sulphur Dioxide, SO2

5 minutes

1,000

0.4

Notes:

[1]   Measured at 298K and 101.325 kPa.

4.3                         Construction Dust Assessment

4.3.1                  Study Area

As discussed in Section 3, construction activities associated with the CKR will be mainly undertaken underground. However, at-grade construction works are still required near both tunnel portals (i.e. West and East Portions), and central access/ventilation shaft in Ho Man Tin, and also a barging facility near Tsing Yi. As such, the construction dust assessment for the Project is separated into 4 areas, namely the West Portion, Central Portion, East Portion, and Barging Point. With reference to the EIA Study Brief for this Project (ESB-156/2006), the study area for air quality impact assessment should generally be defined by a distance of 500m from the boundary of the Project. Figure 4.1.1 to 4.1.4 illustrate the extent of the study area for construction dust assessment in West Portion, Central Portion, East Portion, and Barging Point, respectively.

4.3.2                  Ambient Air Quality Condition

Total suspended particulate (TSP) is of key concern during the construction phase. Historical TSP monitoring data from the Air Quality Monitoring Station (AQMS) in Sham Shui Po, Kwun Tong, and Tsuen Wan operated by EPD have been examined.  The latest 5 published years of air quality monitoring data, i.e. 2007 to 2011 are tabulated in the table below. The 5-year annual average is adopted as representative background air quality concentration.

Table 4.3:   TSP Monitoring Data at Sham Shui Po, Kwun Tong and Tsuen Wan AQMSs (2007-2011)

AQMS

Annual TSP Concentration (μg/m3)

2007

2008

2009

2010

2011

5-year Mean

Sham Shui Po

79

81

77

76

79

78.4

(98%)

Kwun Tong

82

72

70

67

74

73.0

(91%)

Tsuen Wan

79

67

63

63

69

68.2

(85%)

Notes:

% of AQO is provided in the bracket.

Monitoring results exceeded AQO are shown as bolded characters.

 

It is observed from the above table that there were no obvious trends of TSP concentrations in Sham Shui Po, Kwun Tong and Tsuen Wan. The lowest annual TSP concentrations in these three AQMSs were recorded in 2010.

 

In consideration of their individual geographical locations, the 5-year annual TSP averages recorded at Sham Shui Po and Kwun Tong AQMS are adopted as the background TSP concentrations for the West Portion (i.e. 78.4 µg/m3) and East Portion (i.e. 73.0 µg/m3) respectively.  For the Central Portion, the average from Sham Shui Po and Kwun Tong AQMS is adopted (i.e. 75.7µg/m3).  The 5-year annual TSP concentration recorded in Tsuen Wan (i.e. 68.2 µg/m3) is adopted as the background concentration for the Barging Point.

4.3.3                  Air Sensitive Receivers

In accordance with Annex 12 of the TM-EIAO, Air Sensitive Receivers (ASRs) include 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.  Any other premises or places with which, in terms of duration or number of people affected, has a similar sensitivity to the air pollutants as the aforelisted premises and places are also considered as a sensitive receiver. 

 

Representative ASRs within a distance of 500m from the works limit and temporary at-grade work areas have been identified. These ASRs include both the existing and planned developments. Existing ASRs are identified by means of reviewing topographic maps, aerial photos, land status plans, supplemented by site inspections. They mainly include developed residential buildings with different storey height, educational institution and hotels etc.

 

Planned/committed ASRs are identified by making reference to relevant Outline Zoning Plans (OZP), Outline Development Plans, Layout Plans and other published plans in the vicinity of the alignment, including:

·         South West Kowloon (KPA 20) Outline Zoning Plan (No. S/K20/27);

·         Tsim Sha Tsui (KPA 1) Outline Zoning Plan (No. S/K1/26);

·         Yau Ma Tei (KPA 2) Outline Zoning Plan (No. S/K2/21);

·         Ho Man Tin (KPA 6 & 7) Outline Zoning Plan (No. S/K7/22);

·         Hung Hom (KPA 9) Outline Zoning Plan (No. S/K9/24);

·         Ma Tau Kok (KPA 10) Outline Zoning Plan (No. S/K10/20);

·         Kai Tak (KPA 22) Outline Zoning Plan (No. S/K22/4); and

·         Ngau Tau Kok & Kowloon Bay (KPA 13 & 17) Outline Zoning Plan (No. S/K13/27)

For other planned landuses, the relevant stakeholders have been approached to obtain latest planning information such as layout and building height. 

 

The locations of the worst representative ASRs for construction dust assessment are illustrated in Figure 4.1.1 to 4.1.4 and are summarised in the table below.

Table 4.4: Representative ASRs for Construction Dust Assessment

ASR ID

Location

Landuse [1]

No. of Storey

Approx. separation distance from works limit (m)

West Portion

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

E

8

80

W-A2

Charming Garden Block 12

R

23

80

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

E

7

<10

W-A4

Prosperous Garden Block 1

R

28

<10

W-A5

The Coronation

R

30

<10

W-A6

Man Cheong Building

R

18

50

W-A7

Kum Lam Building

R

12

<10

W-A8

Dickson Building

R

18

<10

W-A9

Yau Ma Tei Jockey Club Polyclinic

H

10

<10

W-A10

Alhambra Building

R

15

<10

W-A11

Hong Kong Community College (HKCC) of PolyU

E

19

<10

W-A12

Civil Aid Service Headquarter

GIC

6

20

W-A13

Park Avenue Tower 10

R

35

170

W-A14

Charming Garden Block 1

R

22

70

W-A15

HKMA David Li Kwok Po College

E

8

120

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

GIC

4

<10

W-P5

Hong Kong Red Cross Headquarters (Planned)

GIC

-

<10

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

GIC

4

<10

Central Portion

M-A1

Kar Man House, Oi Man Estate

R

6

<10

M-A2

Carmel on the Hill

R

25

50

M-A3

SKH Tsoi Kung Po Secondary School

E

8

10

M-A4

Man Fuk House Block A

R

15

110

M-A5

Cascades Block A

R

18

110

M-A6

Ko Fai House, Kwun Fai Court

R

9

20

M-A7

The Open University of Hong Kong

E

12

130

M-A8

Kwun Hei Court

R

41

40

M-A9

Housing Authority Headquarters Block 1

GIC

11

<10

M-A10

Ho Man Tin Government Offices

GIC

14

60

M-A11

Choi Man House, Ho Man Tin Estate

R

42

20

M-A12

King Man House, Ho Man Tin Estate

R

15

210

M-A13

Ho Man Tin Swimming Pool

P

-

10

M-A14

Yee Man house

R

41

<10

M-A15

Ho Min Tin Estate Service Reservoir Playground

P

-

50

M-A16

Ko Shan Road Park

P

-

80

M-A17

Kiu Wai Mansion

R

20

370

M-A18

Sun Man House

R

24

<10

M-A19

Ellery Terrance

R

34

290

M-A20

Dragon View (Block 1)

R

20

250

M-P2

Planned Residential Area B (Planned)

R

-

<10

East Portion

E-A1

Hong Kong International Trade and Exhibition Centre

GIC

32

40

E-A2

EMSD Headquarters

GIC

22

10

E-A4

Billion Centre

OU

45

80

E-A5

Kai Fuk Industrial Centre

I

9

130

E-A6

Grand Watefront

R

51

<10

E-A7

Chong Chien Court

R

13

<10

E-A8

Wei Chien Court

R

13

<10

E-A9

Sino Industrial Plaza

I

8

<10

E-A10

HSBC Main Treasury

C

3

30

E-A11

Holy Carpenter Primary School

E

6

<10

E-A12

United Daily News Centre

C

15

<10

E-A13

Merit Industrial Centre

C

11

<10

E-A14

Wyler Gardens

R

13

<10

E-P1 [2]

Site 1B4 – School (Planned)

E

10

240

E-P2 [2]

Site 1I3 – Residential (Planned)

R

32

90

E-P3 [2]

Site 1J1 (Planned)

GIC

16

170

E-P4 [2]

Site 1J3 (Planned)

GIC

8

20

Barging Point

TY-A1

Grand Horizon Block 6

R

36

390

TY-A2

Tai Sang Container and Godown Centre

I

15

360

TY-A3

Tsing Yi Industrial Centre Phase 1

I

15

380

TY-A4

The Hong Kong Jockey Club International BMX Park

P

1

300

Notes:

[1]   R– residential; E – educational; I – Industrial; H – clinic/ home for the aged/hospital; C – commercial; W – worship; GIC – government, institution and community; P – Recreational/Park; OU – Other specified uses (Business)

[2]   Based on the best available information including the implementation plan given in the Legco Paper [CB(1)570/08-09(03)], information from CEDD etc., the planned ASRs (E-P1, E-P2, E-P3 and E-P4) within the ex-Kai Tak airport area may be concurrent of CKR although the implementation programme is still yet to be finalised. Hence, these ASRs are included in the construction dust assessment for a conservative assessment.

4.3.4                  Identification of Pollution Sources and Representative Pollutants

A review on the construction methodology for various works areas along CKR alignment has been conducted. In general, construction dust as the representative pollutants, will be potentially generated mainly from the land-based at-grade construction works including the following activities.  According to HKAQO, the 1-hr, 24-hr and annual concentration would need to be considered.  According to Section 13.2.4.3 of USEPA AP-42, most of the particles in fugitive dust have an aerodynamic diameter of <30 μm.  Hence, it is appropriate to adopt Total Suspended Particulates (TSP) (with aerodynamic diameter ≦30 μm) as the representative pollutant for construction phase.  According to EPD’s Air Quality Report 2011, the major sources for Respirable Suspended Particulates (RSP) include power generation, road transport, etc.  Non-combustion sources only constitute about 14%.  Since construction dust is only one of the sources from non-combustion sources. It is unlikely that RSP is a representative pollutant for construction dust.

·         Site clearance;

·         Soil excavation;

·         Backfilling;

·         Construction of portals and cut-&-cover tunnel;

·         Temporary storage, handling and transportation of material at tunnel exit sites;

·         Barging facilities;

·         Demolition of existing buildings; and

·         Wind erosion of open sites.

Since excavation and backfilling activities near both ends of the CKR tunnel will involve large quantities of earthworks and silty material handling, it is anticipated that there may be dust impact as a result of these activities if mitigation measures are not implemented. For the tunnel construction, since all the construction activities, except the cut-&-cover section, will be undertaken totally underground, dust generated will be confined within the tunnel and no associated dust impact is therefore anticipated.

Construction works in the Central Portion will mainly involve construction of the vertical access shaft for loading of explosives for blasting and the mucking out location for excavated materials. Dust impact is therefore anticipated.

The current construction methodology has proposed the barging facilities near Tsing Yi. Dust emissions due to loading / unloading activities and truck movement are therefore anticipated.

Appendix 4.1 illustrates the at-grade works area for the construction of CKR. Dust emissions from concurrent projects and existing sources would also have potential dust impact on ASRs and the cumulative impacts have been assessed.

4.3.5                  Concurrent Projects

The tentative commencement year for the construction of CKR is 2015, and would take approximately 5-6 years for completion. All potential concurrent projects, which may have cumulative environmental impacts during the construction phase of CKR, have been identified and they are summarised in the table below. Figure 1.4 illustrates the locations of these concurrent projects. The implementation programmes of these concurrent projects are provided by the respective project proponents. Where information is not available, they have been made reference to the best available information such as EIA reports and then confirmed by the respective project proponents for the purpose of this EIA.

Table 4.5: Key Concurrent Projects for Construction Dust Assessment

Key Concurrent Projects

Tentative Construction Programme

Shatin to Central Link – Tai Wai to Hung Hom Section [1]

2012-2018

Kwun Tong Line Extension [2]

2011-2015

Trunk Road T2

2014/2015- end 2020

Kai Tak Development

2009- beyond 2020

Kai Tak Development – Roads D3A & D4A

2014-2017

Express Rail Link – West Kowloon Terminus [3]

2010-2015

Road Works at West Kowloon

2011-2014

Proposed Road Improvement Works in West Kowloon Reclamation Development Phase I

2014-2015

Notes:

[1]   Major civil works will be completed in 2016

[2]   Major civil works will be completed in 2014

[3]   Construction works in West Kowloon area will be completed in 2014.

Liaisons with each of the project proponents of the above concurrent projects have been made in order to obtain the latest available information and details. All the overlapping construction works within 500m from the project boundary of CKR are included for cumulative dust impact assessment.  Where appropriate, references are also made to the approved EIA reports to obtain the details of dust sources. The following briefly describes each concurrent project:

i)                    Shatin to Central Link – Tai Wai to Hung Hom Section (SCL (TAW-HUH))

SCL (TAW-HUH) is an approximately 11km long extension of the Ma On Shan Line (MOL) from Tai Wai through new stations, including Hin Keng Station (HIK), Diamond Hill Station (DIH), Kai Tak Station (KAT), To Kwa Wan Station (TKW), Ma Tau Wai Station (MTW), Ho Man Tin Station (HOM) and connects the West Rail Line at Hung Hom Station (HUH). Most of the sections would be underground except for a section at Hin Keng, and another section at Hung Hom, where the alignments need to be raised and linked with the Ma On Shan Line and the West Rail Line respectively to form a strategic East-West rail corridor.

SCL (TAW-HUH) has commenced its construction in 2012 and is targeted for completion in 2018, while the major civil construction works will be completed by 2016. It will therefore be constructed concurrently with the proposed CKR from 2015 to 2016. Cumulative dust impact is therefore anticipated. All the construction works within 500m from the CKR project boundary during this period, including site clearance, ground excavation, cut-&-cover tunnel section etc., presented in the EIA report for SCL (TAW-HUH) are included in this assessment.

ii)                  Kwun Tong Line Extension (KTE) & associated Essential Public Infrastructure Works (EPIW)

The KTE is an approximately 2.6km extension of the existing Kwun Tong Line from Yau Ma Tei Station to a new railway station at Whampoa and an interchange with SCL (TAW-HUH) at Ho Man Tin Station. The KTE includes the construction of the running line, the proposed Ho Man Tin Station, Whampoa Station and their associated structures.

The construction works of KTE has commenced in mid-2011 and is scheduled for completion in 2015 according to the approved EIA Study “Kwun Tong Line Extension” (AEIAR-154/2010). In particular, all the major civil works would be completed by 2014 and only some minor reinstatement works would be carried out within the first quarter of 2015. Hence, cumulative construction dust impact from KTE and associated EPIW is not anticipated.

iii)                Trunk Road T2

Trunk Road T2 is a dual two-lane trunk road of approximately 3.6 km long connecting the CKR and Tseung Kwan O-Lam Tin Tunnel to form a new strategic highway network in order to relieve the existing heavily trafficked road network in the Central and Eastern Kowloon as well as Tseung Kwan O.

According to the latest implementation programme, the construction of Trunk Road T2 would likely commence in end 2015 and be completed by end 2020, which would interface with the construction of CKR. As such, cumulative dust impact during construction is anticipated.

iv)                Kai Tak Development

Redevelopment plan for the former Kai Tak Airport area is proposed to optimise the development potential of the ex-airport site. It covers a land area of about 328 hectares, including the ex-Kai Tak Airport and existing waterfront area at To Kwa Wan, Kowloon Bay etc. According to the current development plan, the infrastructure works are split into 7 sub-packages, such as Cruise Terminal Development, Trunk Road T2 etc. The developments are anticipated to commence in 2009 for completion beyond 2020.

Based on the construction programme presented in LegCo Papers on Kai Tak Development (LC Paper No. CB(1)570/08-09(03)), cumulative dust impact is expected during the interaction with major dusty construction works associated with the proposed CKR, which will be undertaken in Year 2015. For the purpose of cumulative impact assessment, construction works which are located within 500m from the site boundary of CKR with major overlapping construction in Year 2015 are included. Dust emission strengths presented in the approved EIA Study “Kai Tak Development” (KTD) (AEIAR-130/2009) are adopted where appropriate.

v)                  Kai Tak Development –Roads D3A & D4A

Road D3A and D4A are both dual 2-lane district distributor roads, which are 1.4km and 0.1km long respectively, running on the Runway Precinct of KTD. Road D3A will run along the centre of the Runway Precinct and will replace the original southern section of Road D3 that runs along the waterfront of the Runway Precinct.  Road D4A is an extension of Road D4 connecting to the proposed Road D3A. They will serve the Cruise Terminal, the Tourism Node and the development sites in the Runway Precinct.

The construction of these roads will commence in 2014 tentatively and will be completed by 2017. However, the construction site for Road D3A & D4A will be occupied as the barging facilities for the SCL (TAW-HUH). As such, cumulative dust impact due to the concurrent activities from the barging facilities has been addressed.

vi)                Express Rail Link (XRL) – West Kowloon Terminus

The Hong Kong Section of Guangzhou-Shenzhen-Hong Kong Express Rail Link (XRL) will connect West Kowloon Terminus (WKT) to the Mainland section of XRL at Hongmian Dao. The XRL will provide cross-boundary services between stations in Hong Kong, Futian, Longhua, Humen, Shibi, and other major Mainland cities.

The XRL of approximately 26km long will run as an underground railway in dedicated tunnels from WKT to the boundary crossing point at Huanggang. Major construction works in the vicinity of the CKR includes the construction of the proposed WKT and the cut-&-cover tunnel section near Jordan Road. According to the approved EIA Study “Hong Kong Section of Guangzhou - Shenzhen - Hong Kong Express Rail Link” (AEIAR-143/2009), all the construction works in West Kowloon area is scheduled to be completed by end of 2014. In addition, according to the information presented in the latest approved VEP application (VEP-377/2012), the proposed concrete batching plant is located at 500m away from the CKR project boundary and hence any cumulative impacts are not anticipated to be significant. And the northern portion of the works area for XRL described in the VEP would have been completed before the commencement of the CKR construction, which would therefore not interface with CKR.

vii)              Road works at West Kowloon

Upon the opening of WKT of the XRL and the future development of the West Kowloon Cultural District (WKCD), additional traffic capacity and network restructuring within the West Kowloon Reclamation Area (WKRA) is required to accommodate the increasing traffic demand. The proposed roads include Road D1A, Road D1, Lin Cheung Road-Austin Road West Underpass and upgrading of Austin Road West.

These road works are currently being under construction and are expected to be completed by 2014, which will therefore not interface with CKR. As such, cumulative dust impact during construction phase is not anticipated.

It is understood that the extent of the barriers and locations of the top openings of underpass have been updated in the latest approved VEP application (VEP-368/2012) since its approved EIA Study (AEIAR-141/2009). However, the effect of the barrier is only localized.  The top openings of the underpasses are located about 500m away from the Project and the annual pollutant contributions from these top openings are only insignificant at the nearest identified ASRs under the CKR EIA. It is therefore considered that the abovementioned changes under this VEP would have no significant effect on CKR. 

viii)            Proposed Road Improvement Works in West Kowloon Reclamation Development Phase I

The project is proposed to improve the existing road infrastructure in the West Kowloon Reclamation Development (WKRD) including the WKCD and WKT etc, and to enhance its accessibility to these developments. It consists of some road widening/improvement works and provision of new link roads. These works are scheduled to commence in early 2014 and complete in 2015.

Construction works within 500m from the CKR project boundary are reviewed. According to the latest information available from its Project Profile (PP-450/2011) and the EIA Study Brief (ESB-236/2011), construction activities would include some modifications of bridge structure and construction of road bridges. Given that the requirements stipulated in the Air Pollution Control (Construction Dust) Regulation and good site practices for dust control will be implemented by the Contractor, dust contribution from this project is considered insignificant. In addition, the nearest ASRs under the CKR Project are W-A12 (Civil Aid Service Headquarters) and W-P5 (Hong Kong Red Cross Headquarters (Planned)), which are located about 150m and 200m away from this road improvement works project. These ASRs are/would be central air-conditioned with fresh air intake at higher level, dust generated from ground level would not have significant impact to these nearest ASRs. For ASRs located further away, potential dust impact would be naturally attenuated to an insignificant level due to distance. Hence, cumulative dust impact during construction phase is not anticipated.

4.3.6                  Concurrent Dust Sources

There are 3 existing concrete batching plants (CBPs) within the ex-Kai Tak Airport area, including the Yue Xiu CBP, Glorious CBP, and Yau Lee CBP. Based on the latest information, the Yue Xiu CBP, Glorious CBP and the associated sand depot would cease operation before the commencement of construction of SCL, i.e. 2012. The operation of Yau Lee CBP, on the other hand, would have ceased its operation in 2014 before the occupation of the public rental housing at the same site.  Hence, dust emissions from these CBPs are not anticipated.

According to the EIA report for SCL (TAW-HUH), the site next to To Kwa Wan Station under the SCL project (as shown in Figure 1.3) would be allocated for new CBP under short-term tenancy. This potential new CBP has been assessed in the EIA report for SCL (TAW-HUH). It is considered that the assumptions made in the SCL (TAW-HUH) EIA are the best available information and are therefore adopted in this assessment.

4.3.7                  Emission Inventory

Dust Emission associated with the Project

Fugitive dust impact assessments are carried out based on conservative assumptions of general construction activities which include the following:

·         Heavy construction activities including site clearance, ground excavation, construction of the associated facilities, haul road etc;

·         Wind erosion of all active open sites;

·         Loading/unloading from trucks at barging facilities;

·         All construction activities at all work sites to be undertaken concurrently in order to assess the  worst-case situation;

·         Construction working periods of 26 days a month and 12 hours a day from 7:00am to 7:00pm, except Sundays and public holidays.

The prediction of dust emissions is based on typical values and emission factors from United States Environmental Protection Agency (USEPA) Compilation of Air Pollution Emission Factors (AP-42), 5th Edition. References of the dust emission factors for different dust generating activities are listed below. Calculation of dust emission factors and locations of dust sources are given in Appendix 4.1. Detailed descriptions are also discussed in the following sections.

 

Table 4.6: References of Dust Emission Factors for Different Activities

Operating Sites

Activities

Equations and Assumptions

Reference

All construction and excavation sites

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

E   =   1.2 tons/acre/month of activity or

      =   2.69Mg/hectare/month of activity

 

USEPA AP42, S.13.2.3.3

All construction sites

Wind Erosion

 

E = 0.85 Mg/hectare/yr (24 hour emission)

USEPA AP42, S.11.9, Table 11.9.4

Barging facilities and/or any stockpiles

Loading/Unloading at barging facilities and any stockpile

 

k is particle size multiplier

U is average wind speed

M is material moisture content

USEPA AP42, S13.2.4

Dust emission from construction vehicle movement will generally be limited within the confined worksites and the emission factor given in AP-42 S.13.2.3.3 has taken this factor into account.  Watering facilities will be provided at every designated vehicular exit point.  Since all vehicles will be washed at exit points and vehicle loaded with the dusty materials will be covered entirely by clean impervious sheeting before leaving the construction site, dust nuisance from construction vehicle movement outside the worksites is unlikely to be significant.

Dust Emission associated with the Concurrent Projects / Dust Sources

For the concurrent projects with overlapping construction works including SCL (TAW-HUH), T2 and KTD, and the concurrent dust sources from the potential new CBP in ex-Kai Tak airport area, the associated dust emission sources and emission strength are referenced to the approved EIA Studies for SCL (TAW-HUH) and KTD.

4.3.8                  Assessment Methodology

Dust impact assessment is undertaken using the EPD approved Fugitive Dust Model (FDM).  It is a well-known Gaussian Plume model designed for computing air dispersion for fugitive dust sources.  Modelling parameters including dust emission factors, particles size distributions, surface roughness, etc are referred to EPD’s “Guideline on choice of models and model parameters” and USEPA AP-42.  The density of dust is assumed to be 2.5g/m3.  As discussed in Section 4.3.2, the 5-year annual averaged TSP concentrations (2007-2011) recorded at Sham Shui Po and Kwun Tong AQMS are adopted as the background TSP concentrations of the West Portion (i.e. 78.4 µg/m3) and East Portion (i.e. 73.0µg/m3) respectively. For the Central Portion, the average from Sham Shui Po and Kwun Tong AQMS is adopted (i.e. 75.7µg/m3).  The 5-year annual TSP concentration recorded in Tsuen Wan (i.e. 68.2 µg/m3) is adopted as the background concentration for the Barging Point. A surface roughness of 100 cm is assumed in the model to represent the urbanised terrain.

During daytime working hours (7am to 7pm), it is assumed that dust emissions would be generated from all dust generating activities and site erosion. During night-time non-working hours (7pm to 7am of the next day), Sunday and public holidays, dust emission source would include site erosion only as construction activities during these hours are ceased.

The 1-hour, 24-hour average and annual TSP concentrations are calculated based on real meteorological data for Year 2010, including wind direction, wind speed, temperature and stability collected from the nearest weather stations, i.e. King’s Park (for West Portion and Central Portion), Kai Tak (for East Portion), and Tsing Yi (for Barging Point). The mixing height data from the King’s Park station is also adopted.

Fugitive dust impacts are modeled for ASR heights at 1.5m, 5m and 10m above ground.  Since all the dust generating sources associated with the Project are at ground level only, these assessment levels would therefore represent the worst-case scenario. Both the unmitigated and mitigated scenarios for the project are presented. A 100x100m grid is used to generate pollution contours in order to investigate the pollutant dispersion.

A summary of modelling parameters adopted in the construction dust assessment are given in the table below:

Table 4.7: Modelling Parameters in FDM

Parameters

Input

Remark

Particle size distribution

1.25um = 7%

3.75um = 20%

7.5um = 20%

12.5um = 18%

22.5um = 35%

Reference from S13.2.4.3 of USEPA AP-42

Background Concentration

78.4µg/m3 (West Portion)

75.7µg/m3 (Central Portion)

73.0µg/m3 (East Portion)

68.2µg/m3 (Barging Point)

5-year annual averaged value recorded at Sham Shui Po, Kwun Tong, and Tsuen Wan AQMS

 

Modeling mode

Flatted terrain

-

Meteorological data

Real meteorological data recorded in 2010

 

West Portion & Central Portion (King’s Park meteorological data)

East Portion (Kai Tak meteorological data)

Barging Point (Tsing Yi meteorological data)

 

Anemometer Height

King’s Park : 25m

Kai Tak : 13m

Tsing Yi : 10m

Elevation of anemometer : +90mPD (King’s Park)

+16mPD (Kai Tak)

+43mPD (Tsing Yi)

Ground level of anemometer : +65mPD (King’s Park)

+3mPD (Kai Tak)

+33mPD (Tsing Yi)

Surface Roughness

100cm

-

Emission period

General construction activities during daytime working hours (7 am to 7 pm)

Wind erosion during both day-time (7am to 7pm) and night-time (7pm to 7am of the next day)

-

Assessment height

1.5m, 5m and 10m

-

It is understood that construction activities (except at the Barging Point) will not be taken place on the entire work sites at the same time, but to be undertaken at moving multiple work fronts spread across the work sites. The active areas on each work sites could be best estimated based on the construction method, construction programme and number of operating plants. Based on the engineering information presented in the Appendix 4.2, it is estimated that the hourly percentage of active area are in the range of 1.0% to 7.4%, while the annual percentage of active areas are in the range of 0.8% to 5.5%. As a conservative assessment, it is assumed that the hourly and annual percentage active areas are 15% and 6% respectively.

For short-term 1-hour and 24-hour assessment, construction activities and plants would neither be taken place on the entire work site/work area at the same time nor be concentrated in certain areas of the site close to ASRs at any time during construction period. Notwithstanding this, a conservative “Two Tiers” assessment approach has been adopted. An initial screening test, namely “Tier 1 Screening Test” has been undertaken.  The Tier 1 screening test is conservative and has represented the worst case situation, whereby all the worksites would be active (i.e. 100%).

The purpose of the Tier 1 screening test is to identify the potentially affected areas where construction dust may accumulate. The hot spot areas identified in the Tier 1 assessment have been subsequently assessed by a more focused Tier 2 test, for which it is assumed that the hourly active works areas (i.e. 15%) for the nearby construction sites are positioned closest to the potentially worst affected ASRs, while the active areas for all other construction sites located relative further away from the ASRs remain at 100% as per Tier 1. Thus, the Tier 2 assessment is also very conservative as it assumes that all works activities with the associated plants in the nearby construction sites would be undertaken in the closest proximity to the potentially affected ASRs at the same time, which as mentioned above would not occur in reality.

For the long-term annual concentration assessment, as mentioned above that all the active construction activities would likely be moving work fronts spreading across the whole works site. On this basis, it is assumed that the dust emissions would be distributed across the whole area of each site to reasonably represent this mode of construction works (i.e. a correction factor of 0.06 is applied to the total dust emission rate for prediction of annual concentration).

4.3.9                  Assessment Results (Unmitigated)

The maximum unmitigated Tier 1 1-hour, 24-hour and annual cumulative TSP concentrations at each representative ASR have been assessed and are presented in the tables below.  Exceedances of the relevant AQOs are predicted at most of the ASRs. Hence, mitigation measures are therefore required to reduce the dust impact. Figure 4.2.1 to 4.2.12 illustrate the contours for the cumulative unmitigated 1-hour, 24-hour and annual TSP concentrations in West Portion, Central Portion, East Portion, and Barging Point.

Table 4.8: Predicted Unmitigated Tier 1 Cumulative 1-hour and 24-hour TSP Concentrations at Various Heights above Ground (Including Background Concentration)

ASR ID

Location

1-hour TSP Concentrations at Various Height (μg/m3)

24-hour TSP Concentrations at Various Height (μg/m3)

1.5m

5m

10m

1.5m

5m

10m

West Portion

 

 

 

 

 

 

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

2289

1972

1127

440

406

294

W-A2

Charming Garden Block 12

2512

2076

1083

417

395

308

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

2620

2175

1405

474

446

364

W-A4

Prosperous Garden Block 1

3410

2654

1506

748

608

437

W-A5

The Coronation

4833

2094

1087

903

502

321

W-A6

Man Cheong Building

1818

1604

972

407

345

246

W-A7

Kum Lam Building

4791

3146

1768

692

448

320

W-A8

Dickson Building

5081

3534

1816

886

418

296

W-A9

Yau Ma Tei Jockey Club Polyclinic

2148

2023

1464

481

467

383

W-A10

Alhambra Building

5102

3420

1723

843

625

402

W-A11

Hong Kong Community College (HKCC) of PolyU

4317

2405

1231

841

621

364

W-A12

Civil Aid Service Headquarter

2785

2228

1165

913

706

382

W-A13

Park Avenue Tower 10

1071

1061

857

225

228

205

W-A14

Charming Garden Block 1

1300

1284

1010

304

301

254

W-A15

HKMA David Li Kwok Po College

1646

1551

1083

339

328

264

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

Note [1]

2576

1250

Note [1]

757

450

W-P5

Hong Kong Red Cross Headquarters (Planned)

1465

1356

1017

317

308

252

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

3308

2524

1361

560

502

366

Central Portion

 

 

 

 

 

 

M-A1

Kar Man House, Oi Man Estate

1584

1033

467

327

251

150

M-A2

Carmel on the Hill

702

579

328

190

176

139

M-A3

SKH Tsoi Kung Po Secondary School

2441

1179

568

413

277

145

M-A4

Man Fuk House Block A

925

726

360

280

244

163

M-A5

Cascades Block A

1053

874

457

178

167

133

M-A6

Ko Fai House, Kwun Fai Court

1888

993

371

320

223

146

M-A7

The Open University of Hong Kong

763

686

444

147

142

122

M-A8

Kwun Hei Court

708

614

362

147

137

113

M-A9

Housing Authority Headquarters Block 1

2247

1339

619

351

251

144

M-A10

Ho Man Tin Government Offices

1210

795

404

342

276

164

M-A11

Choi Man House, Ho Man Tin Estate

540

512

373

132

132

121

M-A12

King Man House, Ho Man Tin Estate

364

361

300

96

96

93

M-A13

Ho Man Tin Swimming Pool

3421

1360

566

639

355

171

M-A14

Yee Man house

618

565

375

113

112

106

M-A15

Ho Min Tin Estate Service Reservoir Playground

1668

1014

505

224

194

152

M-A16

Ko Shan Road Park

334

326

261

102

102

97

M-A17

Kiu Wai Mansion

386

374

298

94

94

91

M-A18

Sun Man House

440

413

304

108

106

98

M-A19

Ellery Terrance

447

432

331

109

108

101

M-A20

Dragon View (Block 1)

476

457

345

137

134

118

M-P2

Planned Residential Area B (Planned)

3433

1224

486

642

315

173

East Portion

 

 

 

 

 

 

E-A1

Hong Kong International Trade and Exhibition Centre

Note [2]

4311

2641

Note [2]

601

387

E-A2

EMSD Headquarters

Note [2]

3820

2274

Note [2]

543

433

E-A4

Billion Centre

3058

2625

1730

616

581

444

E-A5

Kai Fuk Industrial Centre

2273

2125

1575

507

501

411

E-A6

Grand Watefront

3064

2011

1377

723

482

296

E-A7

Chong Chien Court

4380

3449

1779

379

340

273

E-A8

Wei Chien Court

6114

3832

2080

890

462

308

E-A9

Sino Industrial Plaza

3274

3232

2503

344

349

310

E-A10

HSBC Main Treasury

3367

3246

2434

411

389

297

E-A11

Holy Carpenter Primary School

2344

2279

1789

354

329

281

E-A12

United Daily News Centre

3382

3253

2419

370

352

285

E-A13

Merit Industrial Centre

2847

2490

1500

300

280

236

E-A14

Wyler Gardens

4972

3765

1927

497

426

317

E-P1

Site 1B4 – School (Planned)

1547

1462

1232

195

192

178

E-P2

Site 1I3 – Residential (Planned)

2494

2270

1507

239

229

202

E-P3

Site 1J1 (Planned)

1676

1615

1240

209

211

194

E-P4

Site 1J3 (Planned)

3512

2729

1407

317

283

227

Barging Point

 

 

 

 

 

 

TY-A1

Grand Horizon Block 6

120

118

107

74

74

72

TY-A2

Tai Sang Container and Godown Centre

121

119

105

72

72

71

TY-A3

Tsing Yi Industrial Centre Phase 1

117

114

102

71

71

70

TY-A4

The Hong Kong Jockey Club International BMX Park

128

123

106

71

71

70

Notes:

[1]   The planned Yau Ma Tei Police Station would be central air-conditioned and the fresh air intake would be at least 5mAG. Hence there is no air sensitive use at 1.5mAG.

[2]   No air sensitive use is observed at 1.5mAG

Table 4.9: Predicted Unmitigated Cumulative Annual TSP Concentrations at Various Heights above Ground (Including Background Concentration)

ASR ID

Location

Annual TSP Concentrations at Various Height (μg/m3)

1.5m

5m

10m

West Portion

 

 

 

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

80.8

80.7

80.3

W-A2

Charming Garden Block 12

80.3

80.2

79.9

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

81.9

81.4

80.7

W-A4

Prosperous Garden Block 1

85.5

84.2

82.4

W-A5

The Coronation

91.2

87.8

84.3

W-A6

Man Cheong Building

80.6

80.4

79.9

W-A7

Kum Lam Building

83.1

81.4

80.1

W-A8

Dickson Building

85.7

82.7

80.7

W-A9

Yau Ma Tei Jockey Club Polyclinic

83.3

82.6

81.3

W-A10

Alhambra Building

81.4

80.8

80.0

W-A11

Hong Kong Community College (HKCC) of PolyU

84.3

83.1

81.4

W-A12

Civil Aid Service Headquarter

85.4

84.5

82.5

W-A13

Park Avenue Tower 10

78.9

79.0

78.9

W-A14

Charming Garden Block 1

79.5

79.5

79.4

W-A15

HKMA David Li Kwok Po College

79.9

79.9

79.7

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

Note [1]

91.9

85.9

W-P5

Hong Kong Red Cross Headquarters (Planned)

79.5

79.5

79.4

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

83.5

83.0

81.8

Central Portion

 

 

 

M-A1

Kar Man House, Oi Man Estate

77.9

77.6

76.9

M-A2

Carmel on the Hill

77.1

77.0

76.7

M-A3

SKH Tsoi Kung Po Secondary School

77.2

76.8

76.4

M-A4

Man Fuk House Block A

76.6

76.5

76.3

M-A5

Cascades Block A

76.0

76.0

75.9

M-A6

Ko Fai House, Kwun Fai Court

77.5

77.0

76.4

M-A7

The Open University of Hong Kong

75.8

75.8

75.8

M-A8

Kwun Hei Court

76.1

76.1

76.0

M-A9

Housing Authority Headquarters Block 1

76.4

76.3

76.1

M-A10

Ho Man Tin Government Offices

77.8

77.5

76.9

M-A11

Choi Man House, Ho Man Tin Estate

75.8

75.8

75.8

M-A12

King Man House, Ho Man Tin Estate

75.7

75.8

75.7

M-A13

Ho Man Tin Swimming Pool

78.1

77.2

76.3

M-A14

Yee Man house

75.9

75.9

75.8

M-A15

Ho Min Tin Estate Service Reservoir Playground

76.7

76.6

76.3

M-A16

Ko Shan Road Park

75.8

75.8

75.8

M-A17

Kiu Wai Mansion

75.8

75.8

75.7

M-A18

Sun Man House

75.9

75.9

75.9

M-A19

Ellery Terrance

75.8

75.8

75.8

M-A20

Dragon View (Block 1)

75.9

75.9

75.9

M-P2

Planned Residential Area B (Planned)

80.0

77.9

76.6

East Portion

 

 

 

E-A1

Hong Kong International Trade and Exhibition Centre

Note [2]

78.5

77.1

E-A2

EMSD Headquarters

Note [2]

76.9

76.0

E-A4

Billion Centre

75.7

75.6

75.2

E-A5

Kai Fuk Industrial Centre

75.5

75.4

75.0

E-A6

Grand Watefront

81.9

80.8

78.7

E-A7

Chong Chien Court

78.4

78.1

77.1

E-A8

Wei Chien Court

81.9

78.9

76.5

E-A9

Sino Industrial Plaza

75.0

75.0

74.8

E-A10

HSBC Main Treasury

75.7

75.7

75.3

E-A11

Holy Carpenter Primary School

74.8

74.5

74.3

E-A12

United Daily News Centre

75.1

74.7

74.4

E-A13

Merit Industrial Centre

77.3

77.3

76.7

E-A14

Wyler Gardens

80.1

79.0

77.1

E-P1

Site 1B4 – School (Planned)

74.5

74.4

74.2

E-P2

Site 1I3 – Residential (Planned)

75.8

75.6

75.2

E-P3

Site 1J1 (Planned)

74.8

74.7

74.4

E-P4

Site 1J3 (Planned)

75.8

75.6

75.2

Barging Point

 

 

 

TY-A1

Grand Horizon Block 6

68.9

68.9

68.9

TY-A2

Tai Sang Container and Godown Centre

68.6

68.6

68.6

TY-A3

Tsing Yi Industrial Centre Phase 1

68.4

68.4

68.4

TY-A4

The Hong Kong Jockey Club International BMX Park

68.4

68.4

68.4

Notes:

[1]   The planned Yau Ma Tei Police Station would be central air-conditioned and the fresh air intake would be at least 5mAG. Hence there is no air sensitive use at 1.5mAG.

[2]   No air sensitive use is observed at 1.5mAG

4.3.10             Recommended Mitigation Measures for Fugitive Dust

In order to reduce the dust emission from CKR and achieve compliances of TSP criteria at ASRs, the following specific mitigation measures are recommended:

i)           Regular watering under a good site practice should be adopted. In accordance with the “Control of Open Fugitive Dust Sources” (USEPA AP-42) as given in Appendix 4.2, 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 based on the average haul road traffic of 54 per hour, average evaporation rate and an assumed application intensity of 1.3 L/m2 for the respective watering frequencies (see Appendix 4.2).  Any potential dust impact and watering mitigation would be subject to the actual site conditions.  For example, for a construction activity that produces inherently wet conditions or in cases under rainy weather, the above water application intensity may not be unreservedly applied.  While the above watering frequencies are to be followed, the extent of watering may vary depending on actual site conditions but should be sufficient to maintain an equivalent intensity of not less than 1.3 L/m2 to achieve the respective dust removal efficiencies.  The dust levels would be monitored and managed under an EM&A programme as specified in the EM&A Manual;

ii)         For the unloading of spoil from trucks at barging point, installation of 3-sided screen with top cover and the provision of water sprays at the discharge point would be provided.  A 50% dust suppression is assumed.  This assumption is based upon USEPA AP-42 Control Techniques for Particulate Emissions form Stationary Sources Part 2 which states that watering alone would have 50% dust removal efficiency.  This is, however, considered very conservative as the barging point would be provided with a 3-sided enclosure, which would provide additional dust containment and control.

In addition, the Contractor is also obliged to follow the procedures and requirements given in the Air Pollution Control (Construction Dust) Regulation. It stipulates the construction dust control requirements for both Notifiable (e.g. site formation) and Regulatory (e.g. road opening) Works to be carried out by the Contractor.  The following dust suppression measures should be incorporated by the Contractor to control the dust nuisance throughout the construction phase:

·            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;

·            Where practicable, vehicle washing facilities with high pressure water jet should be provided at every discernible or designated vehicle exit point.  The area where vehicle washing takes place and the road section between the washing facilities and the exit point should be paved with concrete, bituminous materials or hardcores;

·            When there are open excavation and reinstatement works, hoarding of not less than 2.4m high should be provided as far as practicable along the site boundary with provision for public crossing. Good site practice shall also be adopted by the Contractor to ensure the conditions of the hoardings are properly maintained throughout the construction period;

·            The portion of any road leading only to construction site that is within 30m of a vehicle entrance or exit should be kept clear of dusty materials;

·            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 area that involves demolition activities should be sprayed with water or a dust suppression chemical immediately prior to, during and immediately after the activities so as to maintain the entire surface wet;

·            Where a scaffolding is erected around the perimeter of a building under construction, effective dust screens, sheeting or netting should be provided to enclose the scaffolding from the ground floor level of the building, or a canopy should be provided from the first floor level up to the highest level of the scaffolding;

·            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;

·            Cement or dry PFA delivered in bulk should be stored in a closed silo fitted with an audible high level alarm which is interlocked with the material filling line and no overfilling is allowed;

·            Loading, unloading, transfer, handling or storage of bulk cement or dry PFA should be carried out in a totally enclosed system or facility, and any vent or exhaust should be fitted with an effective fabric filter or equivalent air pollution control system; and

·            Exposed earth should be properly treated by compaction, turfing, hydroseeding, vegetation planting or sealing with latex, vinyl, bitumen, shortcrete or other suitable surface stabiliser within six months after the last construction activity on the construction site or part of the construction site where the exposed earth lies.

For the barging facility near Tsing Yi, the following good site practices are required:

·            All road surface within the barging facilities will be paved;

·            Dust enclosures will be provided for the loading ramp as described in (ii) above;

·            Vehicles will be required to pass through designated wheel wash facilities; and

·            Continuous water spray at the loading point.

These requirements should be incorporated into the Contract Specification for the civil work.  In addition, an audit and monitoring programme during the construction phase should be implemented by the Contractor to ensure that the construction dust impacts are controlled to within the HKAQO. Detailed requirements for the audit and monitoring programme are given separately in the EM&A manual.

4.3.11             Assessment Results (Mitigated)

Short-term Assessment (Tier 1)

The mitigated 1-hour and 24-hour TSP concentrations based on Tier 1 screening test have been predicted. The table below summarizes the cumulative maximum 1-hour and 24-hour TSP impact (Tier 1) at identified ASRs. The results indicate that, for the majority of ASRs, exceedance of 1-hour and 24-hour TSP criteria are not anticipated even assuming the absolute worst case situation, whereby all the worksites would be active (i.e. 100%).  However, exceedances of 1-hour TSP concentrations are still predicted at E-A8 (Wei Chien Court). As the Tier 1 assessment is for screening purposes only and would not represent the actual on-site situation, a more focused Tier 2 assessment has been undertaken at E-A8 (Wei Chien Court).

In addition, contours of Tier 1 1-hour and 24-hour TSP concentrations in West Portion, Central Portion, East Portion and Barging Point are shown in the Figure 4.3.1 to 4.3.10. Contours indicate that there are no exceedances at other locations, except the 1-hour TSP exceedances near W-A7 (Kum Lam Building), W-A8 (Dickson Building), W-A10 (Alhambra Building) in West Portion and near E-A1 (Hong Kong International Trade and Exhibition Centre), E-A2 (EMSD Headquarters), E-A14 (Wyler Gardens), the WSD Kowloon Bay Pipe Yard and the potential residential developments to the east of the Kai Tak River within ex-Kai Tak airport area in East Portion. For the exceedance at WSD Kowloon Bay Pipe Yard, since no air sensitive use is identified within the premises, no adverse dust impact is therefore anticipated. A more focused Tier 2 assessment is therefore conducted at the area near W-A7 (Kum Lam Building), W-A8 (Dickson Building), W-A10 (Alhambra Building) and E-A14 (Wyler Gardens).

For W-P1 (Reprovisioned Yau Ma Tei Police Station (Planned)), E-A1 (Hong Kong International Trade and Exhibition Centre), E-A2 (EMSD Headquarters), it is observed that all the GIC and commercial uses on ground level are central-air conditioned and the fresh air intakes are located at least 5m above ground. It is also expected that the potential residential developments to the east of the Kai Tak River would generally have a ground lobby on the ground floor and the residential flats (i.e. air sensitive uses) located about 5m above ground. Adverse dust impacts on ground level at these ASRs are therefore not anticipated.  However, it is understood that there are elevated dust sources due to the potential new CBP located in the ex-Kai Tak airport area.  As such, contours of Tier 1 1-hour and 24-hour TSP concentrations at 5m above ground in the East Portion are also plotted (Figure 4.3.7 and 4.3.8).  Results show that exceedance of 1-hour TSP near E-A1 (Hong Kong International Trade and Exhibition Centre) at 5m above ground level is anticipated. A more focused Tier 2 assessment is also conducted at area near E-A1 (Hong Kong International Trade and Exhibition Centre).

Table 4.10: Predicted Mitigated Tier 1 Cumulative 1-hour and 24-hour TSP Concentrations at Various Heights above Ground (Including Background Concentration)

ASR ID

Location

1-hour TSP Concentrations at Various Height (μg/m3)

24-hour TSP Concentrations at Various Height (μg/m3)

1.5m

5m

10m

1.5m

5m

10m

West Portion

 

 

 

 

 

 

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

262

236

165

109

106

97

W-A2

Charming Garden Block 12

280

244

162

112

109

100

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

289

252

188

118

113

105

W-A4

Prosperous Garden Block 1

355

292

197

142

128

111

W-A5

The Coronation

473

246

162

158

116

101

W-A6

Man Cheong Building

223

205

153

109

104

94

W-A7

Kum Lam Building

470

333

219

135

113

101

W-A8

Dickson Building

494

365

223

154

110

99

W-A9

Yau Ma Tei Jockey Club Polyclinic

250

240

193

117

115

106

W-A10

Alhambra Building

495

356

215

151

130

109

W-A11

Hong Kong Community College (HKCC) of PolyU

430

271

174

153

130

105

W-A12

Civil Aid Service Headquarter

303

257

169

156

137

107

W-A13

Park Avenue Tower 10

161

160

143

91

91

89

W-A14

Charming Garden Block 1

180

178

156

97

97

93

W-A15

HKMA David Li Kwok Po College

209

201

162

100

99

94

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

Note [1]

286

176

Note [1]

140

112

W-P5

Hong Kong Red Cross Headquarters (Planned)

193

184

156

98

97

93

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

346

281

185

126

119

105

Central Portion

 

 

 

 

 

 

M-A1

Kar Man House, Oi Man Estate

201

155

108

97

91

82

M-A2

Carmel on the Hill

128

117

97

87

85

82

M-A3

SKH Tsoi Kung Po Secondary School

272

167

117

104

92

82

M-A4

Man Fuk House Block A

146

130

99

94

91

83

M-A5

Cascades Block A

157

142

107

84

83

80

M-A6

Ko Fai House, Kwun Fai Court

226

152

100

99

89

82

M-A7

The Open University of Hong Kong

133

126

106

82

81

80

M-A8

Kwun Hei Court

128

120

99

82

81

79

M-A9

Housing Authority Headquarters Block 1

256

181

121

99

90

82

M-A10

Ho Man Tin Government Offices

170

135

103

101

94

84

M-A11

Choi Man House, Ho Man Tin Estate

114

112

100

81

81

80

M-A12

King Man House, Ho Man Tin Estate

100

99

94

77

77

77

M-A13

Ho Man Tin Swimming Pool

353

182

116

125

101

84

M-A14

Yee Man house

121

116

101

80

80

79

M-A15

Ho Min Tin Estate Service Reservoir Playground

208

154

111

89

86

82

M-A16

Ko Shan Road Park

97

96

91

78

78

78

M-A17

Kiu Wai Mansion

101

100

94

77

77

77

M-A18

Sun Man House

106

104

95

79

78

78

M-A19

Ellery Terrance

107

105

97

78

78

78

M-A20

Dragon View (Block 1)

109

107

98

81

81

79

M-P2

Planned Residential Area B (Planned)

354

171

110

130

97

84

East Portion

 

 

 

 

 

 

E-A1

Hong Kong International Trade and Exhibition Centre

Note [2]

486

334

Note [2]

158

130

E-A2

EMSD Headquarters

Note [2]

438

319

Note [2]

131

117

E-A4

Billion Centre

402

385

301

141

139

126

E-A5

Kai Fuk Industrial Centre

344

339

285

132

133

122

E-A6

Grand Watefront

321

285

250

130

112

105

E-A7

Chong Chien Court

454

378

237

108

104

101

E-A8

Wei Chien Court

597

405

259

167

128

109

E-A9

Sino Industrial Plaza

382

379

311

113

115

109

E-A10

HSBC Main Treasury

406

397

319

131

131

120

E-A11

Holy Carpenter Primary School

347

308

251

127

116

107

E-A12

United Daily News Centre

367

358

286

112

111

105

E-A13

Merit Industrial Centre

335

308

223

101

102

99

E-A14

Wyler Gardens

498

399

244

118

112

105

E-P1

Site 1B4 – School (Planned)

343

279

236

130

119

106

E-P2

Site 1I3 – Residential (Planned)

376

299

227

143

131

111

E-P3

Site 1J1 (Planned)

354

285

234

119

114

104

E-P4

Site 1J3 (Planned)

384

320

236

129

125

110

Barging Point

 

 

 

 

 

 

TY-A1

Grand Horizon Block 6

81

80

77

70

69

69

TY-A2

Tai Sang Container and Godown Centre

80

79

76

69

69

69

TY-A3

Tsing Yi Industrial Centre Phase 1

79

78

75

69

69

69

TY-A4

The Hong Kong Jockey Club International BMX Park

80

79

76

69

69

69

Notes:

[1]   The planned Yau Ma Tei Police Station would be central air-conditioned and the fresh air intake would be at least 5mAG. Hence there is no air sensitive use at 1.5mAG.

[2]   No air sensitive use is observed at 1.5mAG

Short-term Assessment (Tier 2)

A more focused Tier 2 assessment has been conducted on ASR E-A8 (Wei Chien Court), area near the W-A7 (Kum Lam Building), W-A8 (Dickson Building) and W-A10 (Alhambra Building), and area near E-A1 (Hong Kong International Trade and Exhibition Centre) and E-A14 (Wyler Gardens) such that the 15% active works areas (as a conservative assumption) for the adjacent construction site are positioned closest to these ASRs, while the active areas from all the other construction sites located relative further away from the ASRs remain at 100% as per Tier 1. As mentioned in Section 4.3.8, the Tier 2 assessment is also very conservative and would over-predict the dust emissions.

The maximum Tier 2 1-hour and 24-hour TSP concentrations have been assessed. The following table summaries the cumulative 1-hour and 24-hour TSP impact (Tier 2) at E-A8. Results show that, both cumulative 1-hour and 24-hour TSP concentrations would comply with the respective criteria and as such, adverse short-term construction dust impact is not anticipated.

Table 4.11: Predicted Mitigated Tier 2 Cumulative 1-hour and 24-hour TSP Concentrations at Various Heights above Ground (Including Background Concentration)

ASR ID

Location

1-hour TSP Concentrations at Various Height (μg/m3)

24-hour TSP Concentrations at Various Height (μg/m3)

1.5m

5m

10m

1.5m

5m

10m

East Portion

 

 

 

 

 

 

E-A8

Wei Chien Court

471

286

222

155

119

104

Contours have been plotted for 1-hour and 24-hour TSP concentrations (Tier 2) at 1.5m above ground for the areas near W-A7 (Kum Lam Building), W-A8 (Dickson Building) and W-A10 (Alhambra Building) in West Portion and E-A8 (Wei Chien Court) and E-A14 (Wyler Gardens) in East Portion, and also at 5m above ground near the E-A1 (Hong Kong International Trade and Exhibition Centre) to illustrate the short-term dust impact on these hot spot areas at the worst affected level and are presented in Figure 4.4.1 to 4.4.6 respectively. Results indicate that there are no active air sensitive uses located within the area of exceedance, and hence adverse short-term dust impact is not anticipated.

 

 

Long-term Assessment

The maximum predicted annual TSP concentrations at identified ASRs in the study area under mitigated case are given in the table below. Contours of annual TSP concentrations at 1.5m above ground have been plotted in Figure 4.5.1, 4.5.2 and 4.5.3. Results indicate full compliance of the relevant criterion at all areas adjacent to the work sites, except the eastern boundary of W-A5 (The Coronation).  However, based on the current layout plan, there will be no air sensitive use at that area. Hence, adverse annual dust impact is not anticipated.

Table 4.12: Predicted Mitigated Cumulative Annual TSP Concentrations at Various Heights above Ground (Including Background Concentration)

ASR ID

Location

Annual TSP Concentrations at Various Height (μg/m3)

1.5m

5m

10m

West Portion

 

 

 

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

78.7

78.6

78.6

W-A2

Charming Garden Block 12

78.6

78.6

78.6

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

78.8

78.7

78.6

W-A4

Prosperous Garden Block 1

79.2

79.0

78.8

W-A5

The Coronation

79.8

79.4

79.0

W-A6

Man Cheong Building

78.6

78.6

78.6

W-A7

Kum Lam Building

78.9

78.7

78.6

W-A8

Dickson Building

79.2

78.8

78.6

W-A9

Yau Ma Tei Jockey Club Polyclinic

78.9

78.8

78.7

W-A10

Alhambra Building

78.7

78.7

78.6

W-A11

Hong Kong Community College (HKCC) of PolyU

79.1

78.9

78.7

W-A12

Civil Aid Service Headquarter

79.2

79.1

78.8

W-A13

Park Avenue Tower 10

78.5

78.5

78.5

W-A14

Charming Garden Block 1

78.5

78.5

78.5

W-A15

HKMA David Li Kwok Po College

78.6

78.6

78.5

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

Note [1]

79.8

79.1

W-P5

Hong Kong Red Cross Headquarters (Planned)

78.5

78.5

78.5

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

79.0

78.9

78.7

Central Portion

 

 

 

M-A1

Kar Man House, Oi Man Estate

76.0

75.9

75.8

M-A2

Carmel on the Hill

75.9

75.8

75.8

M-A3

SKH Tsoi Kung Po Secondary School

75.9

75.8

75.8

M-A4

Man Fuk House Block A

75.8

75.8

75.8

M-A5

Cascades Block A

75.7

75.7

75.7

M-A6

Ko Fai House, Kwun Fai Court

75.9

75.8

75.8

M-A7

The Open University of Hong Kong

75.7

75.7

75.7

M-A8

Kwun Hei Court

75.7

75.7

75.7

M-A9

Housing Authority Headquarters Block 1

75.8

75.8

75.7

M-A10

Ho Man Tin Government Offices

75.9

75.9

75.8

M-A11

Choi Man House, Ho Man Tin Estate

75.7

75.7

75.7

M-A12

King Man House, Ho Man Tin Estate

75.7

75.7

75.7

M-A13

Ho Man Tin Swimming Pool

76.0

75.8

75.8

M-A14

Yee Man house

75.7

75.7

75.7

M-A15

Ho Min Tin Estate Service Reservoir Playground

75.8

75.8

75.8

M-A16

Ko Shan Road Park

75.7

75.7

75.7

M-A17

Kiu Wai Mansion

75.7

75.7

75.7

M-A18

Sun Man House

75.7

75.7

75.7

M-A19

Ellery Terrance

75.7

75.7

75.7

M-A20

Dragon View (Block 1)

75.7

75.7

75.7

M-P2

Planned Residential Area B (Planned)

76.2

75.9

75.8

East Portion

 

 

 

E-A1

Hong Kong International Trade and Exhibition Centre

Note [2]

74.3

74.0

E-A2

EMSD Headquarters

Note [2]

74.0

73.8

E-A4

Billion Centre

73.9

73.9

73.8

E-A5

Kai Fuk Industrial Centre

73.9

73.9

73.7

E-A6

Grand Watefront

74.6

74.5

74.2

E-A7

Chong Chien Court

74.1

74.1

73.9

E-A8

Wei Chien Court

74.4

74.1

73.8

E-A9

Sino Industrial Plaza

73.6

73.6

73.6

E-A10

HSBC Main Treasury

73.8

73.8

73.7

E-A11

Holy Carpenter Primary School

73.8

73.6

73.5

E-A12

United Daily News Centre

74.1

73.7

73.5

E-A13

Merit Industrial Centre

74.0

74.0

73.9

E-A14

Wyler Gardens

74.3

74.1

73.9

E-P1

Site 1B4 – School (Planned)

73.9

73.8

73.6

E-P2

Site 1I3 – Residential (Planned)

74.5

74.3

74.1

E-P3

Site 1J1 (Planned)

74.1

73.9

73.7

E-P4

Site 1J3 (Planned)

74.2

74.2

73.9

Barging Point

 

 

 

TY-A1

Grand Horizon Block 6

68.4

68.4

68.4

TY-A2

Tai Sang Container and Godown Centre

68.3

68.3

68.3

TY-A3

Tsing Yi Industrial Centre Phase 1

68.3

68.3

68.2

TY-A4

The Hong Kong Jockey Club International BMX Park

68.3

68.3

68.2

Notes:

[1]   The planned Yau Ma Tei Police Station would be central air-conditioned and the fresh air intake would be at least 5mAG. Hence there is no air sensitive use at 1.5mAG.

[2]   No air sensitive use is observed at 1.5mAG

4.3.12             Residual Impact for Construction Dust

With the implementation of the mitigation measures as stipulated in the Air Pollution Control (Construction Dust) Regulation, dust control measures, including watering once per hour on exposed worksites and haul road, and good site practices, the predicted 1-hour, 24-hour and annual TSP concentrations on area in the vicinity of the construction sites would comply with the relevant criteria.  Hence, no adverse residual dust impact is anticipated.

4.4                         Operational Air Quality Assessment

4.4.1                  Study Area

The CKR will be mainly underground based on the current design, except for the portals at both ends and the associated connection roads. Vehicular emissions from the open road sections near both tunnel portals and from the three proposed ventilation buildings in Yau Ma Tei, Ho Man Tin and Kai Tak are therefore anticipated.

Operational air quality assessment for CKR will be separated into 3 study areas, namely the West Portion, Central Portion and East Portion. With reference to the EIA Study Brief for this Project (ESB-156/2006), the study area for air quality impact assessment should generally be defined by a distance of 500m from the boundary of the Project.  Emission sources within 500m are included in the near-field models, while emission sources beyond 500m are either included in near-field model or far-field model as appropriate.  Figure 4.6.1, 4.6.2 and 4.6.3 illustrate the extent of study area for West Portion, Central Portion and East Portion respectively. 

4.4.2                  Ambient Air Quality Condition

Vehicular emissions, particularly the nitrogen dioxide (NO2) and respirable suspended particulates (RSP), are the major pollutants during operational phase of the Project.  The nearest EPD’s Air Quality Monitoring Stations (AQMS) to the study areas are Sham Shui Po AQMS and Kwun Tong AQMS. Historical air quality monitoring data from these two stations have been examined.  The latest 5 published years of air quality monitoring data, i.e. 2007 to 2011 are tabulated in the tables below.

Table 4.13: Air Quality Monitoring Data at Kwun Tong AQMS (2007-2011)

Pollutant

Year

Highest 1-hour Average

(μg/m3)

Highest 24-hour Average

(μg/m3)

Annual Average

(μg/m3)

NO2

2007

316

160

63

2008

243

139

59

2009

249

134

58

2010

242

123

59

2011

285

155

63

5-year mean

267 (89%)

142 (95%)

60.4 (76%)

AQO

300

150

80

RSP

2007

273

134

53

2008

238

136

47

2009

226

169

48

2010

785 #

681 #

47

2011

205

117

49

5-year mean

236

139 (77%)

48.8 (89%)

AQO

N/A

180

55

SO2

2007

375

114

19

2008

258

69

17

2009

168

57

11

2010

258

34

10

2011

115

42

12

5-year mean

235 (29%)

63 (18%)

13.8 (17%)

AQO

800

350

80

CO [1]

2007

N/M

N/M

N/M

2008

N/M

N/M

N/M

2009

N/M

N/M

N/M

2010

N/M

N/M

N/M

2011

N/M

N/M

N/M

5-year mean

N/A

N/A

N/A

AQO

30,000

10,000

N/A

O3

2007

161

93

31

2008

185

103

33

2009

242

128

37

2010

143

110

33

2011

181

126

37

5-year mean

182 (76%)

112

34.2

AQO

240

N/A

N/A

Note:

% of AQO is provided in the bracket.

Monitoring results exceeded AQO are shown as bolded characters

N/M – Not measured

N/A – Not applicable since there is no HKAQO for this parameter

#              The value was recorded during a dust plume originated from northern part of China in March 2010 which was an abnormal event and hence has not been taken to calculate the 5-year mean.

[1]           Carbon monoxide is not measured at the Kwun Tong and Sham Shui Po AQMSs

Table 4.14: Air Quality Monitoring Data at Sham Shui Po AQMS (2007-2011)

Pollutant

Year

Highest 1-hour Average

(μg/m3)

Highest 24-hour Average

(μg/m3)

Annual Average

(μg/m3)

NO2

2007

279

143

69

2008

266

169

69

2009

250

158

65

2010

300

147

69

2011

296

155

70

5-year mean

278 (93%)

154 (103%)

68.4 (86%)

AQO

300

150

80

RSP

2007

292

164

57

2008

229

141

53

2009

226

196

47

2010

630 #

569 #

48

2011

213

119

51

5-year mean

240

155 (86%)

51.2 (93%)

AQO

N/A

180

55

SO2

2007

348

109

20

2008

305

93

20

2009

226

125

16

2010

258

78

14

2011

261

79

17

5-year mean

280 (35%)

97 (28%)

17.4 (22%)

AQO

800

350

80

CO [1]

2007

N/M

N/M

N/M

2008

N/M

N/M

N/M

2009

N/M

N/M

N/M

2010

N/M

N/M

N/M

2011

N/M

N/M

N/M

5-year mean

N/A

N/A

N/A

AQO

30,000

10,000

N/A

O3

2007

237

87

27

2008

302

101

27

2009

224

99

30

2010

252

89

28

2011

240

106

31

5-year mean

251 (105%)

96

28.6

AQO

240

N/A

N/A

Note:

% of AQO is provided in the bracket.

Monitoring results exceeded AQO are shown as bolded characters

N/M – Not measured

N/A – Not applicable since there is no HKAQO for this parameter

#              The value was recorded during a dust plume originated from northern part of China in March 2010 which was an abnormal event and hence has not been taken to calculate the 5-year mean.

[1]           Carbon monoxide is not measured at the Kwun Tong and Sham Shui Po AQMSs

It is observed from the above table that, in Kwun Tong area, there were no obvious trends of 1-hour, 24-hour and annual NO2 concentrations. The highest 1-hour NO2 concentrations were ranged from 242µg/m3 in 2010 to 316µg/m3 in 2007, and the highest 24-hour NO2 concentrations were ranged from 123µg/m3 in 2010 to 160 µg/m3 in 2007. The annual NO2 concentrations remained relatively steady in the range of 58 – 63µg/m3, without any exceedance.

For the Sham Shui Po area, there was also no obvious trend observed. The highest 1-hour NO2 concentrations were ranged from 250µg/m3 in 2009 to 300µg/m3 in 2010, and the highest 24-hour NO2 concentrations were ranged from 143µg/m3 in 2007 to 169 µg/m3 in 2008. In particular, the 5-year mean of highest 24-hour NO2 concentration in Sham Shui Po has exceeded the criterion of 150µg/m3. The annual NO2 concentrations were in the range of 65 – 70µg/m3.

For RSP concentrations in both Kwun Tong and Sham Shui Po areas, the highest 24-hour concentrations of 681µg/m3 and 569µg/m3 were recorded in 2010. Nevertheless, these exceedances were due to the dust plume originated from the northern part of Chine in March 2010, which is an abnormal event. Excluding this year, there was a general decreasing trend of 1-hour and 24-hour RSP concentrations in both Kwun Tong and Sham Shui Po AQMS. The annual RSP concentrations had dropped in 2008 and remained rather steady from 2008 to 2011, ranging from 47 – 49µg/m3 and 47 – 53µg/m3 in Kwun Tong and Sham Shui Po AQMS respectively.

The 1-hour, 24-hour and annual SO2 concentrations in both areas were relatively low and well within the AQO.

Highest 1-hour O3 concentrations from 2007 to 2011 were relatively high in both areas, in the range of 143 – 242µg/m3 in Kwun Tong, and 224 – 302µg/m3 in Sham Shui Po. In particular, the 5-year mean of highest 1-hour O3 concentration in Sham Shui Po has exceeded the criterion of 240µg/m3.

4.4.3                  Air Sensitive Receivers

Similar to construction phase, representative ASRs within a distance of 500m from the proposed open road sections covered by this Project and within a distance of 500m from the proposed ventilation buildings have been identified in accordance with Annex 12 of the TM-EIAO.  These ASRs include both the existing and planned developments.  The locations of the representative ASRs for operational air quality assessment during the operation of the Project are illustrated in Figure 4.6.1, 4.6.2 and 4.6.3, and are summarised in the table below.

Table 4.15: Representative ASRs for Operational Air Quality Assessment

ASR ID

Location

Landuse [1]

No. of Storey

Approx. separation distance from works limit (m)

West Portion

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

E

8

80

W-A2

Charming Garden Block 12

R

23

80

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

E

7

<10

W-A4

Prosperous Garden Block 1

R

28

<10

W-A5

The Coronation

R

30

<10

W-A6

Man Cheong Building

R

18

50

W-A7

Kum Lam Building

R

12

<10

W-A8

Dickson Building

R

18

<10

W-A9

Yau Ma Tei Jockey Club Polyclinic

H

10

<10

W-A10

Alhambra Building

R

15

<10

W-A11

Hong Kong Community College (HKCC) of PolyU

E

19

<10

W-A12

Civil Aid Service Headquarter

GIC

9

20

W-A13

Park Avenue Tower 10

R

35

170

W-A14

Charming Garden Block 1

R

22

70

W-A15

HKMA David Li Kwok Po College

E

8

120

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

GIC

4

<10

W-P3

West Kowloon Government Offices (Planned)

GIC

25

<10

W-P4

Indoor Recreation Centre (Planned)

GIC

-

<10

W-P5

Hong Kong Red Cross Headquarters (Planned)

GIC

-

<10

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

GIC

4

<10

W-P7

Primary School (Planned)

E

8

<10

W-P8

Hindu Temple (Planned)

W

10

70

Central Portion

M-A1

Kar Man House, Oi Man Estate

R

6

<10

M-A2

Carmel on the Hill

R

25

50

M-A3

SKH Tsoi Kung Po Secondary School

E

8

10

M-A4

Man Fuk House Block A

R

15

110

M-A5

Cascades Block A

R

18

110

M-A6

Ko Fai House, Kwun Fai Court

R

9

20

M-A7

The Open University of Hong Kong

E

12

130

M-A8

Kwun Hei Court

R

41

40

M-A9

Housing Authority Headquarters Block 1

GIC

11

<10

M-A10

Ho Man Tin Government Offices

GIC

14

60

M-A11

Choi Man House, Ho Man Tin Estate

R

42

20

M-A12

King Man House, Ho Man Tin Estate

R

15

210

M-A13

Ho Man Tin Swimming Pool

P

-

10

M-A14

Yee Man house

R

41

<10

M-A15

Ho Man Tin Estate Service Reservoir Playground

P

-

50

M-A16

Ko Shan Road Park

P

-

80

M-A17

Kiu Wai Mansion

R

20

370

M-A18

Sun Man House

R

24

<10

M-A19

Ellery Terrance

R

34

290

M-A20

Dragon View (Block 1)

R

20

250

M-P1

Valley Road Estate Redevelopment (Planned)

R

48

160

M-P2

Planned Residential Area B (Planned)

R

-

<10

M-P3

Ho Man Tin South Phase 2 (Planned)

R

150mPD [2]

<10

M-P4

Ho Man Tin Redevelopment (Outline Zoning Plan No. S/K7/21 ) (Planned)

R

120mPD [2]

80

M-P5

Ho Man Tin Redevelopment (KIL 11128) (Planned)

R

-

100

M-P6

Hong Kong Polytechnic University Student Hostel Phase 3 (Planned)

R

120mPD [2]

320

East Portion

E-A1

Hong Kong International Trade and Exhibition Centre

GIC

32

40

E-A2

EMSD Headquarters

GIC

22

10

E-A4

Billion Centre

OU

45

80

E-A5

Kai Fuk Industrial Centre

I

9

130

E-A6

Grand Watefront

R

51

<10

E-A7

Chong Chien Court

R

13

<10

E-A8

Wei Chien Court

R

13

<10

E-A9

Sino Industrial Plaza

I

8

<10

E-A10

HSBC Main Treasury

C

3

30

E-A11

Holy Carpenter Primary School

E

6

<10

E-A12

United Daily News Centre

C

15

<10

E-A13

Merit Industrial Centre

C

11

<10

E-A14

Wyler Gardens

R

13

<10

E-P1

Site 1B4 – School (Planned)

E

10

240

E-P2

Site 1I3 – Residential (Planned)

R

32

90

E-P3

Site 1J1 (Planned)

GIC

16

170

E-P4

Site 1J3 (Planned)

GIC

8

20

E-P5

Site 1L3 - Residential (Planned)

R

15

130

E-P6

Site 1L2 - Residential (Planned)

R

32

100

E-P7

Site 2D2 – Stadium (Planned)

GIC

17

15

E-P8

Site 2D1 – Stadium (Planned)

GIC

17

260

E-P9

Site 1P – Administration Building (Planned)

GIC

8

<10

E-P10

Site 3C1 – Hospital (Planned)

H

14

110

E-P11

Site 3C1 – Hospital (Planned)

H

14

60

E-P12

Site 3D2 – Commercial (Planned)

C

30

440

E-P13

Site 4Ab – Metro Park (Planned)

P

-

310

E-P14

Site 4Aa – Metro Park (Planned)

P

-

<10

E-P15

Site 5A4a (Planned)

CDA

20

40

E-P16

Site 5A4b (Planned)

CDA

32

50

E-P17

Site 3B1- Secondary School (Planned)

E

10

30

E-P18

Site  3B1 (Planned)

NA[3]

-

15

Notes:

[1]   R– residential; E – educational; I – Industrial; H – clinic/ home for the aged/hospital; C – Commercial; W – worship; GIC – government, institution and community; P – Recreational/Park; OU – Other specified uses (Business); CDA – Comprehensive Development Area

[2]   Outline Zoning Plan No. S/K7/22

[3]   No information available. Landuse zoned as “undefined”.

4.4.4                  Identification of Representative Air Pollutants

As discussed in Section 4.2, the Air Pollution Control Ordinance (APCO) (Cap 311) and its subsidiary regulations define statutory AQOs for 7 common air pollutants including NO2, SO2, TSP, RSP, CO, O3 and lead. According to Clause 3.4.6.3(vi)(b) of the EIA Study Brief,  the key / representative air pollutant parameters for CKR shall be identified, including the types of pollutants and the averaging time concentration. 

The air quality pollutant source during the operational phase of CKR would be the emission from the vehicles travelling on the new and existing roads.  The tailpipe emission would comprise a number of pollutants, including Nitrogen Oxides (NOx), Respirable Suspended Particulates (RSP), Sulphur Dioxides (SO2), Toxic Air Pollutants (TAP), Lead (Pb) etc. As discussed in the following sections, only the NO2 and RSP are considered the key air quality pollutant for this highway infrastructure project and the concentrations of the other pollutants are very low and hence are not considered as the key pollutants for the purposes of this air quality assessment.  The issue on Ozone (O3) which is highly influenced by the regional situation would also be discussed.

i)                    Nitrogen Dioxide (NO2)

Nitrogen oxides (NOx) is known to be one of the pollutants emitted by vehicles.  According to the 2010 Hong Kong Emission Inventory Report published by EPD (http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf) which is the latest available information by the time of preparing this report, the dominant source of NOx generated in HK is the navigation which constitutes about 32% of the total in 2010.  Road transport is the second largest NOx emission group, accounting for about 30% of the total (see table below).

Table 4.16: The emission percentage and the amount of NOx in Hong Kong (2010)

Pollutant Source Categories

NOx Emission %[1]

NOx Emission (tons) [1]

Public Electricity Generation

25%

27,000

Road Transport

30%

32,700

Navigation

32%

35,000

Civil Aviation

4%

4,350

Other Fuel Combustion

9%

9,520

Non-combustion

N/A

N/A

Total

100%

109,000

Note:

[1]   Figures extracted from 2010 Hong Kong Emission Inventory Report

(http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf)

Together with VOC and in the presence of O3 under sunlight, NOx would be transformed to NO2.  As discussed in Section 4.4.2, the latest 5-year average of annual NO2 concentrations in Kwun Tong and Sham Shui Po are about 76% and 86% of the AQOs respectively.

The operation of CKR would inevitably increase the traffic flow and hence the NOx emission and subsequently the NO2 concentrations near to the roadside.  Hence, NO2 is one of the key / representative pollutants for the operational air quality assessment of the Project. 1-hour, 24-hour and annual averaged concentrations at each identified ASRs would be assessed and compared with the relevant AQO to determine the compliance.

ii)                  Respirable Suspended Particulates (RSP or PM10)

Respirable Suspended Particulates (RSP or PM10) refers to suspended particulates with a nominal aerodynamic diameter of 10µm or less. According to the EPD’s data, (http://www.epd.gov.hk/epd/english/environmentinhk/ air/data/files/2010HKEIReportEng.pdf), and other research studies (Tian et al., 2011 & Wie-Zhen et al., 2008), road vehicles, particularly diesel vehicles, are one of the sources of RSP in Hong Kong. 

According to the latest statistics of 2010 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf), road transport is the second largest source of RSP accounting for 21% of the total emissions.  As discussed in Section 4.4.2, the latest 5-year average of the annual RSP concentration in Kwun Tong and Sham Shui Po are about 89% and 93% of the AQO respectively. 

Table 4.17: The emission percentage and the amount of RSP in Hong Kong (2010)

Pollutant Source Categories

RSP Emission % [1]

RSP Emission (tons) [1]

Public Electricity Generation

16%

1,010

Road Transport

21%

1,340

Navigation

36%

2,260

Civil Aviation

<1%

54

Other Fuel Combustion

12%

778

Non-combustion

14%

898

Total

100%

6340

Note:

[1]   Figures extracted from 2010 Hong Kong Emission Inventory Report

(http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf)

The operation of CKR would inevitably increase the traffic flow and hence the RSP concentrations near to the roadside.  Hence, RSP is also one of the key representative pollutants for the operational air quality assessment of the Project. The 24-hour and annual averaged concentrations at each identified ASRs would be assessed and compared with the relevant AQOs to determine the compliance.

iii)                Sulphur Dioxide (SO2)

According to the latest statistics of 2010 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf), the dominant sources of Sulphur Dioxide (SO2) in Hong Kong are electricity generation and navigation which constitute the majority of the emissions (about 98%).  Although SO2 is also one of the pollutants emitted by vehicles, road transport is the smallest emission source of SO2 and only constitutes less than 1% of the total SO2 (see the following table).  The introduction of ultra low sulphur diesel for vehicle fleet in Year 2000 has also helped reducing the SO2 emission in Hong Kong.

Table 4.18: The emission percentage and the amount of SO2 in Hong Kong (2010)

Pollutant Source Categories

SO2 Emission %[1]

SO2 Emission (tons) [1]

Public Electricity Generation

50%

17,800

Road Transport

<1%

286

Navigation

48%

16,900

Civil Aviation

<1%

299

Other Fuel Combustion

<1%

268

Non-combustion

N/A

N/A

Total

100%

35,500

Note:

[1]   Figures extracted from 2010 Hong Kong Emission Inventory Report

(http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf)

As discussed in Section 4.4.2, the latest 5-year average of annual SO2 concentrations in Kwun Tong and Sham Shui Po are only 17% and 22% of the AQO respectively.  This clearly indicates that the AQOs for SO2 could be well achieved with great margin in the study area.  Given that road transport only contributes a very small amount of SO2 and there is still a large margin to the AQO compared to the other pollutants such as RSP and NO2, it is considered appropriate to select RSP and NO2, but not SO2 as the key pollutants for quantitative assessment for the operational phase of a road project.

iv)                Ozone (O3)

According to the EPD’s “Air Quality in Hong Kong 2011”, O3 is a regional air pollution problem which affects the entire PRDEZ, including Hong Kong. The following table summarises the Year 2011 O3 monitoring data in Hong Kong extracted from the EPD’s report titled “Air Quality in Hong Kong 2011”. It can be seen that the highest 1-hour O3 concentration in various regions of Hong Kong would exceed the existing AQO.  The O3 concentration at Tap Mun which is away from any highway infrastructures and industrial sources is also very high.  This implies that O3 is highly influenced by regional sources instead of local emission sources.  This is also in line with other studies such as Y. Sun study in 2011 – “In situ measurements of SO2, NOx, NOy, and O3 in Beijing, China during August 2008”[4-1] and “In situ measurements of NO, NO2, NOy, and O3 in Dinghushan (112°E, 23°N), China during autumn 2008”[4-2] .

Table 4.19: 2011 Ozone monitoring data extracted from “Air Quality in Hong Kong 2011”

Station

Highest 1-Hour Conc (μg/m3) [1]

(AQO=240)

Highest Daily Conc (μg/m3) [2]

 

Annual Avg. Conc (μg/m3) [2]

 

Central/Western

278

128

36

Eastern

257

126

46

Kwai Chung

213

102

28

Kwun Tong

181

126

37

Sham Shui Po

240

106

31

Tsuen Wan

223

112

31

Sha Tin

241

157

43

Tai Po

260

153

48

Tung Chung

312

144

44

Yuen Long

310

131

39

Tap Mun

316

167

71

Note:

[1]   Bolded values mean exceedance of the AQO.

[2]   Ozone does not have a 24-hour and annual AQOs.

Unlike other pollutants such as NOx, O3 is not a primary pollutant emitted from man-made sources but is formed by a set of complex chain reactions between various chemical species, including NOx and VOC, in the presence of sunlight.  According to Sun et al. and Dahlmann et al. the rate of formation of O3, also known as Ozone Production Efficiency, depends not only on NOx and VOC levels, but atmospheric oxidation, temperature, radiation, and other meteorological factors in the atmosphere of different regions. The formation of O3 generally takes several hours to proceed (EPD, 2009)[4-3] and therefore O3 recorded locally could be attributed to emissions generated from places afar.

According to “A Study Review Hong Kong’s Air Quality Objectives” (http://www.epd.gov.hk/epd/english/environmentinhk/air/studyrpts/aqor_report.html), due to the abundance of its precursors (VOC and NOx) from a great variety of sources such as motor vehicles, industries, power plants and consumer products, etc., ozone can be widely formed in the region and can be transported over long distance.  The general rising trend of ozone levels in Hong Kong over the past years reflects an aggravation in the photochemical smog problem on a regional scale.  All these indicate that local traffic emission is not a dominant controlling factor in O3 formation.

According to the EPD’s “Air Quality in Hong Kong 2011” report, NOx emissions from motor vehicles have the potential to react with and remove O3 in the air, and regions with heavy traffic normally have lower ozone levels than areas with light traffic.  It is therefore possible that the Project may contribute to a decrease in O3 in the immediate area along main roads. O3 is therefore not considered as a key air pollutant for the operational air quality assessment of the Project.

v)                  Carbon Monoxide (CO)

Carbon Monoxide (CO) is one of the primary pollutants emitted by road transport. According to the latest statistics of 2010 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf), CO emissions from road transport contributed about 68% of total CO emission in 2010 (see the table below).

Table 4.20: The emission percentage and the amount of CO in Hong Kong (2010)

Pollutant Source Categories

CO Emission %

CO Emission (tons)

Public Electricity Generation

5%

3,310

Road Transport

68%

47,600

Navigation

16%

11,400

Civil Aviation

4%

2,530

Other Fuel Combustion

7%

5,100

Non-combustion

N/A

N/A

Total

100%

70,000

It is understood that road transportation is the dominant source of CO emission; nevertheless, the air quality impact due to CO is still relatively minor considering its existing concentrations. The highest 1-hour, 8-hour and annual CO concentrations in Hong Kong for Year 2011 are summarised in the following table.

Table 4.21: 2011 CO monitoring data extracted from “Air Quality in Hong Kong 2011”

Station

Highest 1-Hour Conc (μg/m3) [1]

(AQO=30000)

Highest 8-hour Conc (μg/m3)

(AQO=10000)

Annual Avg. Conc (μg/m3) [2]

 

Tsuen Wan

2730

2158

585

Tung Chung

2290

2188

660

Yuen Long

3210

2610

677

Tap Mun

1490

1459

752

Causeway Bay

4030

3309

1010

Central

3790

2516

820

Mong Kok

3110

2400

1034

Note:

[1]   Bolded values mean exceedance of the AQO.

[2]   CO does not have annual AQO.

It is clearly indicated that the AQOs for CO could be well achieved with great margin in the study area. The highest 1-hour CO concentration and highest daily CO concentration in Mong Kok are only 10% and 24% of their respective AQOs, which are both far below the criteria.  Given that there is still a large margin to the AQO compared to the other pollutants such as RSP and NO2, it is considered appropriate to select RSP and NO2, but not CO as the key pollutants for quantitative assessment for the operational phase of a road project.

vi)                Toxic Air Pollutants (TAPs)

There are six kinds of Toxic Air Pollutants (TAPs) routinely monitored in HK, including polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), carbonyls, and toxic elemental species.

Dioxins, carbonyls, PCBs and most toxic elemental species are not considered primary sources of vehicular emissions (http://www.epd.gov.hk/epd/ english/environmentinhk/air/studyrpts/assessment_of_tap_measurements.html & http://www.eea.europa.eu/publications/EMEPCORINAIR5/Sources_of_PCB_emissions.pdf/view), and hence, these three TAPs are not considered as key / representative air pollutants for the operational air quality assessment.

Vehicular emissions may be a source of diesel particulate matters, PAHs and VOCs.  Elemental carbon, which constitutes a large portion of diesel particulate matters mass, is commonly used as a surrogate for diesel particulate matter. According to the data from EPD, the elemental carbon showed a significant decrease in concentration in Mong Kong by 47.5% from 2001 to 2009, and Tsuen Wan by 51.3% from 1999 to 2009.   This is because the implementation of EURO III vehicle emission standard to goods vehicle and bus in 2001 and EURO IV standard to all types of vehicle in 2006-2007 (http://www.epd.gov.hk/epd/english/ environmentinhk/air/data/emission_inve.html).  It is not considered as a key air pollutant for the operational air quality assessment.

Currently, no ambient air quality standards have been set for PAHs.  However, with reference to US and European Community air quality guidelines, the European commission has a very stringent guideline concentration for PAHs.  According to the latest EPD study report in 2011 - “Annual Air Quality Monitoring Results - Air Quality in Hong Kong 2011” (http://www.epd-asg.gov.hk/english/report/files/AQR2011e_final.pdf), the concentration of PAHs level (Benzo[a]pyrene, BaP) in Hong Kong was 0.22 ng/m3 monitored at both the Tsuen Wan and Central/Western stations respectively in 2011 which was still much lower than the guidelines of European Communities of 1ng/m3.

Table 4.22: Comparison of TAPs concentration in Hong Kong (2011) and the EU Air Quality Standards

Air Pollutants

Guidelines / Standards (ng/m3)

Highest Avg Conc at Tsuen Wan station (ng/m3)

Highest Avg Conc at Central/Western station

(ng/m3)

Compliance

EU

EU

PAHs (BaP)

1 (Annual Average)[1]

0.22

(Annual Average)[2]

0.22

(Annual Average)[2]

Well Achieved

Note:

[1] Referenced from http://ec.europa.eu/environment/air/quality/standards.htm

[2] Referenced from http://www.epd-asg.gov.hk/english/report/files/AQR2011e_final.pdf

There are different standards for different VOC compounds. According to the latest EPD study report in 2011 – “Annual Air Quality Monitoring Results - Air Quality in Hong Kong 2011” (http://www.epd-asg.gov.hk/english/report/ files/AQR2011e_final.pdf), benzene, 1-3 butadiene, formaldehyde and perchloroethylene are the VOCs that may have more health concern, and the USEPA also identified benzene and 1-3 butadiene are carcinogenic.

Table 4.23: Comparison of VOCs concentration in Hong Kong (2011) and the EU Air Quality          Standards

TAP

Guidelines / Standards (μg/m3)

Highest Avg Conc at Tsuen Wan station (μg/m3)

Highest Avg Conc at Central/Western station (μg/m3)

Compliance

Benzene

5 (Annual Average) [1]

1.62

1.53

Well Achieved

1-3 butadiene

2.25 (Running Annual Average) [1]

0.13

0.13

Well Achieved

Formaldehyde [2]

9 (Annual Average) [3]

-

3.61

Well Achieved

Perchloroethylene

40 (Annual Average) [4]

0.47

0.51

Well Achieved

Note:

[1] Referenced from the  UK National Air Quality Strategy (NAQS)

(http://www.medway.gov.uk/environmentandplanning/environmentalhealth/airquality/airqualityfordevelopers.aspx)

[2]  The measurement of formaldehyde was affected by influence from renovation works at Princess Alexandra Community Centre as well as nearby buildings of Tsuen Wan Station. Hence, only formaldehyde concentration at the Central/Western station is reported.

[3]  Referenced from the Office of Environmental Health Hazard Assessment (OEHHA) Toxicity Criteria Database, California, USA (http://www.oehha.ca.gov/tcdb/index.asp)

[4]  Referenced from the Integrated Risk Information System (IRIS), USEPA ( http://www.epa.gov/iris/subst/0106.htm)

As shown in the above table, the measured VOCs concentration in Hong Kong urban area is far below the UK and US standards.  Also, according to Hong Kong Air Pollutants Emission Inventory (http://www.epd.gov.hk/epd/english/ environmentinhk/air/data/emission_inve.html), the VOCs level has dropped by approximately 50% in 2007 since 1990 due to the EPD progressive improvement of EURO standard vehicles over the past two decades.  With reference to the EPD’s 2010 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/english/environmentinhk/air/data/files/2010HKEIReportEng.pdf), vehicular emission is also not the primary source of VOCs, accounting for about 23% of the total in Hong Kong. Besides, according to another study - “Seasonal and diurnal variations of volatile organic compounds (VOCs) in the atmosphere of Hong Kong” [4-4], benzene, and 1-3 butadiene only contributed about 6-13% of overall vehicular emission VOCs. In other words, only 1.6-3.5% of the overall VOC emissions in Hong Kong are benzene and 1-3 butadiene contributed by vehicular emission.

The historical monitoring data showed that the concentrations of PAHs and VOCs were only in small amount.  It is also reasonably believed that the emission of PAHs and VOCs should be significantly decreased after the implementation of EURO V standard vehicles in 2013; and the elimination of most of the pre-EURO standard and EURO I vehicles.  The TAPs is also not specified under the current AQO.  Based on above reasons, TAPs is not considered as a key air pollutant for the operational air quality assessment.

vii)              Lead (Pb)

As leaded petrol had been banned in Hong Kong in 1999, it is no longer considered as a primary source in Hong Kong.  According to the “Annual Air Quality Monitoring Results - Air Quality in Hong Kong 2011” from EPD (http://www.epd-asg.gov.hk/english/report/files/AQR2011e_final.pdf), the measured 3-month averaged lead level was ranging from 0.020 μg/m3 (Kwun Tong and Central/ Western) to 0.104 μg/m3 (Yuen Long).  The measured concentration is much lower than the 3-month AQO of 1.5 μg/m3. Therefore, lead is not considered as a key / representative air pollutant for the operational air quality assessment.

As discussed in above, NO2 and RSP have been concluded to be the representative air pollutants.  These two pollutants are stipulated in the HKAQO.  Hence, it is considered appropriate to adopt the time averaging as stipulated in the HKAQO.

4.4.5                  Pollution Sources and Concurrent Projects

4.4.5.1           Vehicular Emission from Open Road

As discussed in Section 4.4.4, the NO2 and RSP are the two key air pollutants generated from road traffic emissions during operational phase of the Project. Other than vehicular emissions from project related roads, those from the concurrent projects, such as the Road works at West Kowloon, planned road networks associated with Kai Tak Development, T2, etc. would also have cumulative air quality impact on nearby ASRs. The table below shows a summary of concurrent projects that would generate cumulative impact from open road and induced traffic. Figure 4.7.1, 4.7.2 and 4.7.3 illustrate the road networks within 500m of each study area (i.e. West Portion, East Portion and Central Portion).

Table 4.24: Concurrent Projects included in the Operational Air Quality Assessment

Concurrent Projects

Tentative Commissiong Year

Trunk Road T2

End 2020  [3]

Planned road networks associated with Kai Tak Development

Road D2 – End 2017

Road D3 (part) – 2020

Road D4 & Road D3 (part) – End 2017

Kai Tak Development (KTD) – Roads D3A & D4A

2017

Road works at West Kowloon

2014

Proposed Road Improvement Works in West Kowloon Reclamation Development Phase I

2015

Tseung Kwan O - Lam Tin Tunnel and Associated Works (TKO-LTT) [1]

End 2020

Cross Bay Link (CBL) [1]

End 2020

West Kowloon Cultural District (WKCD) [1]

Starting from 2013 (in stages)

Express Rail Link – West Kowloon Terminus [2]

2015

Notes:

[1]   The TKO-LTT and WKCD are located outside 500m of the study areas and hence the road networks are excluded in the model.  However, the traffic forecast has also been taken into account the induced traffic from these concurrent projects.

[2]   Induced traffic has been taken into account.

[3]   A number of traffic model scenarios have been investigated in the TIA studies.  It was agreed with TD that, with Road T2 and CBL in place, traffic would be diverted outside the 500m of study area, resulting in less traffic volume.  It was concluded in the TIA that the scenario with CKR and TKO-LTT (but without T2 and CBL) is the critical and worst assessment scenario for CKR EIA Study. The TD’s endorsement letter is given in Appendix 4.3A.

Liaisons with the respective project proponents of the above concurrent projects have been made to obtain the latest available project information and details. Where information is not available, references have been made to the approved EIA reports which are regarded as the best available information at the time of preparing this EIA.

4.4.5.2           Vehicular Emission from Tunnel Portal and Ventilation Building

Based on current tunnel ventilation design of the CKR, vehicular emission inside the tunnel will be discharged to atmosphere via the three proposed ventilation buildings, i.e. West Ventilation Building (WVB) located in Yau Ma Tei (West Portion), Central Ventilation Building (CVB) in Ho Man Tin (Central Portion) and East Ventilation Building (EVB) in Kai Tak (East Portion).  Limited emission from the CKR tunnel portals would be achieved in order to reduce potential air quality impact in this area.  The tunnel ventilation system is designed with the objective to remove/dilute vehicle emissions to achieve the air quality standards specified in EPD’s “Practice Note on Control of Air Pollution in Vehicle Tunnels”, and to maintain limited discharge of emission from the portals.  In addition, to further reduce the air quality impact, an air purification system (APS) will be adopted which will remove the pollutant concentrations before releasing to atmosphere via the three ventilation buildings. As described in Section 3.2.9, the proposed APS will comprise two main processes: the use of Electro-static Precipitators (ESP) to remove the particulates and the NO2 removal system, either using specially prepared activated carbon filter media or decomposing modules which are periodically regenerated on site by “washing” with chemical solutions such as ammonia, potassium hydroxide or sodium sulphite etc.  The current APS design aims to achieve a removal efficiency of 80% for particulate and 80% for NO2.  Figure 4.7.1, 4.7.2 and 4.7.3 illustrate the locations of the proposed tunnel portals, the associated landscape deck and ventilation buildings associated with CKR in each study area.

Other than those tunnel portals and ventilation buildings of the CKR mainline, there are also proposed full enclosures on other roads associated with CKR including those on Hoi Wang Road, reprovision section of GRF and near Prosperous Garden and tunnels for Ring Road and Slip Road S3. Besides, the existing and planned tunnel/enclosure portals and ventilation buildings within the study areas that would also have cumulative air quality impact on nearby ASRs.  Figure 4.7.1, 4.7.2 and 4.7.3 illustrate the locations of these existing/planned tunnel portals and ventilation buildings in each study area and a summary is given in the table below.

Table 4.25:    Existing and Planned Tunnel/Enclosure Portals and Ventilation Buildings included in the Operational Air Quality Assessment

Existing and Planned Tunnel/Enclosure Portals and Ventilation Buildings

Tentative Commissiong Year

CKR Associated

 

Proposed full enclosure on Hoi Wang Road

End 2020

Proposed full enclosure over the reprovision section of Gascoigne Road Flyover

End 2020

Proposed full enclosure near Prosperous Garden

End 2020

CKR- Tunnel for Ring Road and Slip Road S3

End 2020

Existing and Planned

 

Trunk Road T2 - Tunnel for Ring road near Kai Tak Runway

End 2020

KTD - Proposed landscape deck for Road D2

End 2017

Road works at West Kowloon - Proposed underpass and tunnel portals for Austin Road/ Lin Cheung Road, and the proposed landscape decks at Lin Cheung Road

2014

Kai Tak Tunnel and ventilation building

Existing

Western Harbour Crossing (WHC) – Tunnel portal and ventilation building in West Kowloon area

Existing

Cherry Street Tunnel

Existing

4.4.5.3           Industrial Emission

Chimney survey and desktop study have been conducted to identify existing and planned chimneys within 500m study area.  The chimney information, including fuel consumption rate, stack height, gas exhaust velocity, exhaust temperature and the internal diameter of the stack etc have been collected from the respective operators where available.  References have also been made to the approved EIA studies (e.g. the approved KTD EIA report for the planned hospital in Kai Tak) and specified process licence (e.g. SP licence for the Towngas plant in Ma Tau Kok).  Summary of all identified existing/planned chimneys in each study area and their locations are given in Figure 4.7.4, 4.7.5 and 4.7.6.  As confirmed by the operators, some of them have no longer been used and some are being used for emergency only.  The table below lists the chimneys that are included in the operational air quality assessment.

Table 4.26: Existing and Planned Chimneys included in the Operational Air Quality Assessment

Source ID

Description

Operation Mode

West Portion

W1

Boiler at Tak Yue Restaurant

Continuously in-use

W2

Boiler at Tak Yue Restaurant

Continuously in-use

W3

Boiler at Tak Yue Restaurant

Continuously in-use

W4

Boiler at Mei Du Restaurant

Continuously in-use

East Portion

HOS

Planned Hospital in KTD

Planned Hospital

TG_1

Specified Process Licence for HKCG

Continuously in-use

TG_2

Specified Process Licence for HKCG

Continuously in-use

TG_3

Specified Process Licence for HKCG

Continuously in-use

TG_4

Specified Process Licence for HKCG

Continuously in-use

TG_16

Specified Process Licence for HKCG

Continuously in-use

Notes:

[1]   No chimneys being operated in Middle Portion.

4.4.5.4           Marine Emission

The existing To Kwa Wan Typhoon Shelter (TKWTS) is partially within 500m of the Project boundary and the cumulative air quality impact due to the gaseous emission from marine vessels berthing at TKWTS has also been assessed.  Reference has been made to the approved EIA report “Kai Tak Development” (KTD) (AEIAR-130/2009) and the “Study on Marine Vessels Emission Inventory, Final Report (February 2012)” published by EPD for the emission details.   It is observed from the site survey that there are only about 20 barges/vessels within the TKWTS and all of them have no activities.  This observation is in line with that from the approved KTD EIA Study.  It has therefore assumed 20 barges with auxiliary engine operating within the TKWTS in this assessment.  Unlike the Public Cargo Working Areas (PCWAs), there are no loading/unloading activities at typhoon shelter. The typhoon shelter only provides a sheltered space to protect the vessels during typhoons and inclement weather conditions. Its occupancy shall reach its maximum only during typhoon period and all vessels shall not be operated. Thus, assuming 20 barges with auxiliary engine operating within the TKWTS is very conservative in this assessment.

Apart from the TKWTS, there is no other marine emission within 500m of the Project.  However, for conservative assessment, it has also considered to include the major emission source immediately outside 500m in the near-field dispersion model for assessing the cumulative air quality impacts (i.e. the committed cruise terminal at Kai Tak).  Reference has also been made to the KTD EIA report and the “Study on Marine Vessels Emission Inventory, Final Report (February 2012)” published by EPD for the emission details of the cruise terminal.

According to the Port Control (Public Cargo Working Areas) Order 2011 gazetted in December 2011, the Kwun Tong Public Cargo Working Areas (PCWAs) which is outside 500m of the Project will be decommissioned to make way for the development of the Kwun Tong Promenade Stage 2. All the operations at the PCWA had already moved out (i.e. no operation within the KTTS). As such, there is no marine emission anticipated from the Kwun Tong PCWAs, and hence are not included in the cumulative impact assessment.

Figures 4.7.6 illustrates the locations of the cruise terminal and the existing TKWTS in the East Portion study area.

4.4.5.5           Helicopter Emission

A heliport is proposed at the end of the Kai Tak Runway under the KTD.  Although it is outside 500m of the Project, it is considered as a potential major emission and hence its cumulative air quality impact on nearby ASRs has been assessed in the near-field dispersion model.  Reference has been made to the approved EIA Study “Kai Tak Development” (KTD) (AEIAR-130/2009) for the emission details of the proposed heliport.  Figure 4.7.6 illustrates the locations of the proposed heliport in the East Portion study area.

4.4.5.6           Summary of Projects and Sources Included in Operational Air Quality Assessment

A summary of emissions from projects and sources included in Operational Air Quality Assessment is tabulated below:

Table 4.27: Projects/Sources for Operational Air Quality Assessment

Projects / Sources

Associated air quality impact

West Portion

CKR and associated connection roads [1]

Vehicular emission from portal of the CKR tunnel and its associated landscape deck, ventilation building, as well as the connection roads

Express Rail Link – West Kowloon Terminus

Vehicular emission from its induced traffic

Road Works at West Kowloon [1]

Vehicular emission from its road network, induced traffic, proposed underpass and tunnel portals for Austin Road/ Lin Cheung Road, and the proposed landscape decks at Lin Cheung Road, as well as its induced traffic

Proposed Road Improvement Works in West Kowloon Reclamation Development Phase I

Vehicular emission from its road network and induced traffic

West Kowloon Cultural District

Vehicular emission from its induced traffic only

Proposed full enclosure on Hoi Wang Road [1]

Vehicular emission from portal

Proposed full enclosure over the reprovision section of Gascoigne Road Flyover [1]

Vehicular emission from portal

Proposed full enclosure near Properous Garden [1]

Vehicular emission from portal

Western Harbour Crossing (WHC) [1]

Vehicular emission from tunnel portal and ventilation building

Cherry Street Tunnel [1]

Vehicular emission from tunnel portal

Other existing road networks within 500m

Vehicular emission from all open roads

Boiler at Tak Yue Restaurant

Chimney emission

Boiler at Mei Du Restaurant

Chimney emission

Middle Portion

CKR central ventilation building [1]

Vehicular emission from ventilation building

Other existing road networks within 500m

Vehicular emission from all open roads

East Portion

CKR and associated connection roads [1]

Vehicular emission from portal of the CKR tunnel, landscape deck, CKR-Ring Road, and Slip Road S3, ventilation building, as well as the connection roads

Kai Tak Tunnel [1]

Vehicular emission from tunnel portal and ventilation building

Trunk Road T2 [1]

Vehicular emission from its road network, induced traffic, and tunnel portals from Ring road near Kai Tak Runway

Kai Tak Development [1]

Vehicular emission from its road network, induced traffic, and portals from the proposed landscape deck for Road D2

KTD – Roads D3A & D4A

Vehicular emission from its road network and induced traffic

Tseung Kwan O - Lam Tin Tunnel and Associated Works (TKO-LTT)

Vehicular emission from its induced traffic only

Cross Bay Link (CBL)

Vehicular emission from its induced traffic only

Other existing road networks within 500m

Vehicular emission from all open roads

Planned Hospital in KTD

Chimney emission

Specified Process Licence for HKCG

Chimney emission

Kai Tak Development – Cruise Terminal

Marine emission

To Kwa Wan Typhoon Shelter

Marine emission

Kai Tak Development – Heliport

Gaseous emission from the helicopter

Notes:

[1]   The locations of tunnel portals and ventilation buildings are illustrated in Appendix 4.8.

Other than the emission sources described in the above table, the background concentration have also included the influence of other emission such as marine emission, power plant, airports, etc (see Section 4.4.6.3).  Hence, together with the above emission sources, the cumulative impact would have included all the major air pollutant sources.

4.4.6                  Assessment Methodology

4.4.6.1           In-tunnel Air Quality

It is the responsibility of the Applicant to ensure that the air quality inside comply with EPD's "Practice Note on Control of Air Pollution in Vehicle Tunnels".  The air quality inside the tunnel should meet the EPD recommended standard of 1ppm NO2 concentration.  Air quality within the tunnel is to be monitored and the tunnel ventilation system is designed with the objective to remove/ dilute vehicle emissions so that air quality inside will comply with stated air quality standards. Appendix 4.3 describes how the air pollutant within the proposed CKR tunnel is derived and addressed in this EIA study.

4.4.6.2           Determination of Assessment Year

According to Clause 3.4.6.3 (v) (b) of the EIA Study Brief for the Project, the air pollution impacts of future road traffic shall be calculated based on the highest emission strength from road within the next 15 years upon commencement of operation of the Project.  The selected assessment year should represent the highest emission scenario, given the combination of emission factors and traffic flow for the selected year.

Vehicular tailpipe emissions from open roads are calculated based on the EPD EMFAC-HK model v2.1 at the time of assessment (end 2012).  However, the latest model version EMFAC-HK v2.5 is just released by EPD in early January 2013.  As concluded in the “Outline of Changes in January 2013 Release of EMFAC-HK” in EPD website, the overall effects on emission estimates are insignificant.  There are only some changes in the output file formats due to items removal as comparing with v2.1.  Besides, one output file name is also changed and the format for input files is changed from VKT to VMT to ensure the consistency in units used in input files (US units).  The above format changes would not impose any change in the emission rate.  Therefore, the vehicular tailpipe emission rates generated from v2.1 are still adopted in this assessment.  The emission refers to the combination of the following:

·         Vehicular emission from CKR and its associated road networks;

·         Vehicular emission from road networks within 500m of the West Portion study area (i.e. road networks within 500m of the open section of CKR, widening of Gascoigne Road Flyover (GRF), portal and ventilation building of CKR);

·         Vehicular emission from road networks within 500m of the Middle Portion study area (i.e. road networks within 500m of the ventilation building since the CKR is in tunnel form in the middle section);

·         Vehicular emission from road networks within 500m of the East Portion study area (i.e. road networks within 500m of the open section of CKR, portal and ventilation building of CKR).

Based on the current programme, the CKR is planned for comissioning by the end of 2020.  Therefore, EmFAC-HK models have been carried out for Year 2021, 2026 and 2036 (15 years after commissioning) to determine the highest emission and hence the worst assessment year.  The traffic forecast data is given Appendix 4.4.  The methodology, key model assumptions and results (including emission factors) are presented in Appendix 4.5.

The total vehicular emissions within the study areas are summarized in the table below. Results indicate that the highest NOx and RSP emission scenario occurs at Year 2021 and hence is the worst assessment year for operational air quality assessment.

Table 4.28: Summary of Total Daily Pollutant Emissions

Year

Total NOx Emission (gram/day)

Total RSP Emission (gram/day)

2021

1240802

59302

2026

843940

46803

2036

514304

32588

4.4.6.3           Prediction of the Future Background Air Quality

PATH (Pollutants in the Atmosphere and their Transport over Hongkong) is a regional air quality model developed by EPD to simulate air quality over Hong Kong against the Pearl River Delta (PRD) as background. For EIA applications, it simulates wind field, pollutant emissions, transportation and chemical transformation and outputs pollutant concentrations over Hong Kong and the PRD region at a fine grid size of 1.5km.

 

During the 12th Hong Kong-Guangdong Joint Working Group Meeting on Sustainable Development and Environmental Protection (Nov 2012), the Hong Kong and Guangdong Governments jointly endorsed a Major Air Pollutant Emission Reduction Plan for the Pearl River Delta Region up to year 2020. A comprehensive emission inventory for Hong Kong and PRD was compiled for year 2010 based on current best estimates and projected to 2015 and 2020 in accordance with the emission reduction measures proposed in the plan. The emission inventory for year 2010 was used in PATH and produced reasonable agreement with air quality measurements. The emission inventories for years 2015 and 2020 were also used in PATH to predict air qualities for future years. The Hong Kong emission inventories are summarized in Tables 29a-29c.

 

Table 29a: Summary of 2010 Hong Kong Emission Inventory for the PATH model

Emission Group

Annual Emission (2010) Tonnes/Yr

SO2

NOx

RSP

VOC

Public Electricity Generation

17800

27000

1010

413

Road Transport

286

32700

1340

7900

Navigation

16900

35000

2260

3660

Civil Aviation

299

4350

54

396

Other Fuel Combustion

268

9520

778

849

Non-combustion

N/A

N/A

898

20500

Total

35500

109000

6340

33700

 

 

 

Table 29b: Summary of 2015 Hong Kong Emission Inventory for the PATH model

Emission Group

Annual Emission (2015) Tonnes/Yr

SO2

NOx

RSP

VOC

Public Electricity Generation

12500

27600

830

390

Road Transport (1)

305

20070

809

5122

Navigation

13102

35760

2359

3830

Civil Aviation (2)

493

6670

89

433

Other Fuel Combustion(3)

225

8000

654

713

Non-combustion

N/A

N/A

965

21527

Total

26625

98100

5706

32015

 

Table 29c: Summary of 2020 Hong Kong Emission Inventory for the PATH model

Emission Group

Annual Emission (2020) Tonne/Yr

SO2

NOx

RSP

VOC

Public Electricity Generation

6180

20900

560

360

Road Transport (1)

322

11000

540

1640

Navigation

15695

37010

2440

3867

Civil Aviation (2)

650

8770

120

570

Other Fuel Combustion(3)

228

8100

697

720

Non-combustion

N/A

N/A

1032

21488

Total

23075

87200

5389

28645

Notes:

1.   Emissions from Road Transport for years 2015 and 2020 are estimated based on VKTs forecast provided by the Transport Department and EMFAC-HK Model version 2.1.

2.   Emissions from Civil Aviation for years 2015 and 2020 are estimated based on ATM of 362,000 and 476,000 respectively.

3.   Emissions from the following major facilities are considered in the inventory: HK & China Gas, Green Island Cement and Integrated Waste Management Facilities.

PATH model was used to quantify the background air quality during the operational phase of the Project. Emission sources including roads, marine, airports, power plants and industries within the Pearl River Delta Economic Zone and Hong Kong were considered in the PATH model. Details of the PATH Model and related emission inventory can be found in EPD’s web site. The hourly pollutant concentration data predicted by PATH for year 2020 are provided by EPD and adopted in the calculation of cumulative impact in the Project.  However, since the vehicular emission at local scale (i.e. the road networks within the study areas mentioned in Section 4.4.6.2) is modeled by near-field dispersion model CALINE, the respective emission has been removed from the concerned grids to avoid overestimation and the PATH model has been re-run. The updated PATH background concentrations for the concerned grids which cover the study areas of this Project for Year 2020 are extracted in Appendix 4.6.

4.4.6.4           Prediction of the Vehicular Emission from Open Road

The EMFAC-HK estimates the hourly vehicular emission (in tonne) for each road category.  The USEPA approved near field air dispersion model, CALINE4 developed by the California Department of Transport has been used to assess vehicular emissions impact from all existing and planned open road network. The CALINE4 requires input of the emission rates (in gram per mile per vehicle). The hourly emission rates for each vehicle class (in gram per mile per vehicle) are obtained by dividing the hourly emissions calculated in the EMFAC-HK by the Vehicle Kilometres Travelled (VKT) for the respective hour.  The calculation of the NOx and RSP emission factors are given in Appendix 4.5.  The composite vehicle emission factors for each road link for the assessment year 2021 is given in Appendix 4.7.

Grid-specific composite real meteorological data extracted from EPD’s PATH model are adopted in CALINE4 model, including relevant temperature, wind speed, direction and mixing height.  The stability classes are obtained from a separate PCRAMMET model.  The mixing height is capped to 121m as per the real meteorological data.  For the treatment of calm hours, the approach recommended in the "Guideline on Air Quality on Air Quality Models Version 05" has been adopted.

The surface roughness height is closely related to the land use characteristics, and the surface roughness is estimated as 10 percent of the average height of physical structures within 1km study area.  Surface roughness of 100cm is assumed to represent the urbanized terrain. The wind standard deviation is estimated in accordance with the “Guideline on Air Quality Models (Revised), 1986”, as summarized in the table below.

Table 4.30:     Summary of Wind Standard Deviation for Surface Roughness of 100cm

Stability Class

Wind Standard Deviation

A

32.9

B

32.9

C

25.6

D

18.3

E

11.0

F

5.6

Ozone Limiting Method (OLM) was adopted for conversion of NOx to NO2, using the predicted O3 and NO2 levels from PATH model.  According to EPD’s Guidelines on Choice of Models and Model Parameters, the vehicular tailpipe NO2 emission is assumed to be 7.5% of NOx.

Owing to the constraint of the CALINE4 model in modelling elevated roads higher than 10m, the road heights of elevated road sections in excess of 10m high above local ground or water surface are set to 10m in the model as the worst-case assumption.  For barriers along roads or any proposed noise barriers as a noise mitigation measures, the line source has been modelled at the tip of the barrier and the mixing width is limited to the actual uncovered road width in order to address the associated secondary environmental impact.  The road type of the concerned section is set to the “fill” option in CALINE4.

4.4.6.5           Prediction of the Vehicular Emission from Tunnel Portals and Ventilation Buildings

The USEPA approved model, ISCST3, is adopted to model the vehicular emission from tunnel portals, portals of landscape deck/full enclosure and ventilation buildings. Portal emissions are modeled in accordance with the Permanent International Association of Road Congress Report (PIARC, 1991), where it is assumed that the pollutant will be ejected from the portal as a portal jet such that 2/3 of the total emission will be dispersed within first 50m from the portal, and 1/3 of the total emission within the second 50m. To take into account the horizontal jet effect, portal emission is modeled as “Volume” source.  On the other hand, emissions from the ventilation buildings are modeled as “Point” source in ISCST3.  The pollution sources that are covered in the near field dispersion ISCST3 model include the following:

(A)  Portal emission from CKR tunnel and associated landscape deck

The total length of the CKR tunnel is approximately 3.75km and the CVB is at some 1.75km from the eastern portal (i.e. 2km from western portal).  The current tunnel ventilation system is designed to extract a portion of emission (e.g. p%) from the first 1.75km of the west bound tunnel (WBT) to the CVB. The p% depends on the design of the air flow rates of the ventilation fans which would vary for different hours.  The remaining portion of emission (e.g. 100-p%) will be mixed with that from the second 2km of WBT and 90% of these emission will then be ventilated to WVB.  The remaining 10% from the western tunnel portal will be mixed with the vehicular emission inside the connecting landscape deck and the total emission will be emitted via 3 openings (i.e. CKR and landscape deck portal, portal of the CKR emergency road and CKR east bound tunnel). The emissions from each portal are estimated based on the traffic split.

Similar tunnel ventilation system is applied to the CKR east bound tunnel (EBT).  However, since it is considered possible that all emissions inside the western landscape deck will be drawn into the EBT, it has therefore assumed all emissions from the CKR landscape deck to be drawn into the EBT for conservative assessment.  The tunnel ventilation system will extract a portion of emission (e.g. p%) from the first 2.0km of the EBT and from the landscape deck to the CVB. The p% depends on the design of the air flow rates of the ventilation fans which would vary for different hours. The remaining portion of emission (e.g. 100-p%) will be mixed with that from the second 1.75km of EBT and 90% of these emission will then be ventilated to EVB.  The remaining 10% will be emitted via the CKR eastern tunnel portal.  Calculation of the CKR portal emissions is provided in Appendix 4.8.

(B)  Emission from CKR ventilation buildings

An APS will be adopted which will remove the pollutant concentrations before discharging to atmosphere via the three ventilation buildings. The current APS design aims to achieve a removal efficiency of 80% for particulate and 80% for NO2 (i.e. assuming tailpipe NO2 emission to be 7.5% of NOx). Two modules will be operated at the CVB for all hours.  For WVB and EVB, two modules will be operated from 00:00 to 07:00 and three modules will be operated from 07:00 to 24:00. In addition, the APS will be switched off from 01:00 to 06:00 for regular daily maintenance. The current design of the ventilation buildings including air flow rate, exit velocity, exit temperature, discharge heights, exhaust directions, exhaust area is provided by the engineer and summarised in Appendix 4.8.  The emission calculation is also presented in the appendix.

Based on the current design, the emission from CVB and EVB will be discharged in an upward direction; while that from WVB will be discharged at an inclined 45 degree upward direction towards the sea.  Since the ISCST3 model cannot simulate the dispersion from an inclined discharge, the exit velocity of the discharge has been set as the vertical component of the inclined discharge velocity.  The horizontal component of the inclined discharge velocity was not simulated in the model.  As the emission is discharged towards the sea and the ASRs are located at least 150m away on the opposite direction of the discharge, the effect of the discharge plume on these ASRs should be very insignificant.

(C)  Portal emission from full enclosure on Hoi Wang Road, full enclosure at the Prosperous Garden, full enclosure over re-provisioned Gascoigne Road Flyover, proposed landscape deck on CKR at East Portion,  Cherry Street tunnel, Trunk Road T2 - Ring road, CKR - Ring Road, Slip Road S3, proposed landscape deck for Road D2 in KTD

The portal emissions from the proposed full enclosure on Hoi Wang Road, full enclosure at the Prosperous Garden, full enclosure over re-provisioned Gascoigne Road Flyover, proposed landscape deck on CKR at East Portion, as well as T2 – Ring road, CKR – Ring Road and Slip Road S3 road are calculated based on the Year 2021’s projected traffic flow and vehicular emission factors as given in Appendix 4.5.  Appendix 4.8 shows the calculation of these portal emissions.

(D) Emission from Kai Tak tunnel portals and associated ventilation building

Assumption on the emission split between ventilation building and Kai Tak Tunnel (i.e. 50/50%) has been made with reference to the approved EIA Study “Kai Tak Development” (AEIAR-130/2009) (KTD EIA) and the emissions are calculated based on the Year 2021’s projected traffic flow and vehicular emission factors.  Appendix 4.8 presents the calculations for the emission from Kai Tak tunnel portal and its associated ventilation building.  Details on the release height, exit temperature, exit velocity and equivalent stack diameter for the ventilation building assumed in the model are also given in the appendix.

(E)  Emission from the proposed underpass and tunnel portals for Austin Road/ Lin Cheung Road, and the proposed landscape decks at Lin Cheung Road

For all tunnel/underpass/landscape deck associated with the Road Works at West Kowloon, the same modeling approach and assumptions presented in the approved EIA Study “Road Works at West Kowloon” (AEIAR-141/2009) (WKRW EIA) have been adopted.  Four scenarios are considered in the model run i.e. assuming 10%, 20%, 30% and maximum % (depending on the length of the opening concerned) of the portal emissions to be dispersed at the ground-level openings and the worst worst impact results amongst the 4 scenarios have been taken for conservative assessment.  The emission calculations for the portals and the open sections of the underpasses based on the Year 2021’s projected traffic flow and vehicular emission factors are presented in Appendix 4.8.

(F)  Emission from portals of Western Harbour Crossing (WHC) and its associated ventilation building

Since there is no information available for the percentage split of emission between the tunnel portals and ventilation buildings, the following modelling scenarios on three typical cases have been carried out

·         Scenario 1: Assume 30% of emissions inside tunnel are emitted from portal and 70% from ventilation building

·         Scenario 2: Assume 50% of emissions inside tunnel are emitted from portal and 50% from ventilation building

·         Scenario 3: Assume 100% of emissions are emitted from portal (as per the approved WKRW EIA)

The emission calculations for the WHC portals and its ventilation building based on the Year 2021’s projected traffic flow and vehicular emission factors are presented in Appendix 4.8.  The worst impact results amongst these three scenarios have been taken for conservative air quality assessment.

Similar to CALINE4, grid-specific composite real meteorological data extracted from EPD’s PATH model have been adopted in ISCST3 model.  “Urban” mode is applied.  OLM is adopted for conversion of NOx to NO2, using the predicted O3 and NO2 levels from PATH model.  According to EPD’s Guidelines on Choice of Models and Model Parameters, the vehicular tailpipe NO2 emission is assumed to be 7.5% of NOx.

4.4.6.6           Prediction of the Emission from Industrial Chimneys

All chimneys being continuously in use or being planned within 500m of each study area as identified in Section 4.4.5.3 have been included in the near-field dispersion model.  For the chimneys for the restaurant identified in West Portion, the latest information on the fuel consumption rate, stack height, diameter, exit velocity and temperature was provided by the chimney operator.  Where there is no available information, assumptions have been made with reference to EPD’s Guidelines on Choice of Models and Model Parameters.  The NOx and RSP emissions (in g/s) are calculated based on the respective emission factors for boilers in accordance with the USEPA AP-42 Section 1.3.  The assumptions on the emission rate, stack height, diameter, exit velocity and temperature for the chimney in the planned hospital in KTD are based on the approved KTD EIA report and for the Towngas plant in Ma Tau Kok are based on the SP licence.  A summary of all these emission calculations for the identified chimneys are given in Appendix 4.9. 

The potential air quality impact associated with the industrial emissions has been assessed by the EPD approved dispersion model, ISCST3. All these emissions have been modeled as “Point” source in the model.  For conservative assessment, it is assumed that they will be operated continuously over 24 hours.  OLM is adopted for conversion of NOx to NO2, using the predicted O3 and NO2 levels from PATH model.  The in-stack NO2:NOx ratio for the industrial chimneys is assumed to be 10%.

4.4.6.7           Prediction of the Emission from Marine Vessels

As mentioned in Section 4.4.5.4, all the operations within the KTTS had already moved out and there is no marine emission anticipated. For emissions associated with the committed cruise terminal near the end of Kai Tak Runway and the existing TKWTS, they have been estimated in accordance with the latest information extracted from the approved KTD EIA report and the “Study on Marine Vessels Emission Inventory, Final Report (February 2012)” published by EPD. Detailed calculations are presented in Appendix 4.9.

The USEPA approved model, ISCST3, is used to model the gaseous emission from marine vessels.  The marine emission from the planned cruise terminal has been modeled as “Point” source while that from the typhoon shelters has been modeled as “Area” source. OLM is adopted for conversion of NOx to NO2, using the predicted O3 and NO2 levels from PATH model.  The in-stack NO2:NOx ratio for the marine vessels is assumed to be 10%.

4.4.6.8           Prediction of the Emission from Helicopter

There is also no updated information on the planned heliport in KTD and hence the approved KTD EIA report is considered as the best available information. The USEPA approved model, ISCST3, is used to model the gaseous emission from the heliport based on the emission rate extracted from the KTD EIA report (as presented in Appendix 4.9).  “Volume” source has been adopted.  For conservative assessment, it is assumed that they will be operated continuously over 24 hours.  The in-stack NO2:NOx ratio for the helicopters is assumed to be 10%.

4.4.6.9           Prediction of the Cumulative Air Quality Impact

The cumulative operational air quality is a combination of the emission impact at local scale (i.e. open road from CALINE4, tunnel portals, ventilation buildings, chimneys, marine vessels and helicopters from ISCST3) and background air quality impact from other concurrent and regional sources (i.e. from PATH) on an hourly basis.  OLM is used for conversion of NOx to NO2 based on the O3 level from PATH directly as described in the above sections.  As a conservative approach, the OLM is applied separately to the following groups of emission sources:

West Portion

·         Group A – All open roads + All tunnel/landscape deck portals + All underpass

·         Group B – CKR ventilation building

·         Group C – WHC ventilation building

·         Group D – Industrial chimney (low rise)

·         Group E – Industrial chimney (high rise)

Middle Portion

·         Group A – All open roads

·         Group B – CKR ventilation building

East Portion

·         Group A – All open roads + All tunnel/landscape deck portals

·         Group B – CKR ventilation building

·         Group C – Kai Tak Tunnel ventilation building

·         Group D – Towngas plant in Ma Tau Kok

·         Group E – Planned hospital in KTD

·         Group F – Planned cruise terminal and To Kwa Wan Typhoon Shelter

·         Group G – Helicopter

The maximum 1-hour, 24-hour and annual NO2 and RSP concentrations are then determined at each ASR at 10 levels (including 1.5m 5m, 10m, 20m, 30m, 40m, 50m, 60m, 70m and 80m) and compared with the respective AQOs. 

4.4.7                  Assessment Results

The maximum 1-hour, 24-hour and annual NO2 and RSP concentrations at each ASR have been assessed the results are presented in the table below. Detailed results are presented in Appendix 4.10. It can be seen from the table below that all the predicted maximum NO2 and RSP concentrations are all within the respective criteria. Contours of maximum 1-hour NO2 concentrations and maximum 24-hour and annual NO2 and RSP concentrations at the worst affected level (i.e. 1.5m above ground) in West, Central and East Portions are plotted in Figure 4.8.1 to 4.8.15. It is also observed that there are no areas of exceedances. Hence adverse cumulative air quality impact during the operational phase is not anticipated.

Table 4.31:     Predicted Maximum Cumulative 1-hour, 24-hour and Annual Averaged Concentrations of NO2 and RSP at representative ASRs (Including Background Concentrations)

ASR ID

Location

Max. NO2 Concentration (μg/m3)

Max. RSP Concentration (μg/m3)

1-hour

24-hour

Annual

24-hour

Annual

West Portion

 

 

 

 

 

W-A1

Yau Ma Tei Catholic Primary School (Hoi Wang Road)

251

104

57.3

112

43.1

W-A2

Charming Garden Block 12

264

107

59.2

113

43.2

W-A3

Yau Ma Tei Catholic Primary School (Tung Kun Street)

273

125

56.6

113

43.0

W-A4

Prosperous Garden Block 1

283

122

58.3

113

43.2

W-A5

The Coronation

268

119

56.1

112

43.1

W-A6

Man Cheong Building

280

122

58.0

113

43.2

W-A7

Kum Lam Building

284

132

64.4

113

43.6

W-A8

Dickson Building

284

131

61.9

113

43.5

W-A9

Yau Ma Tei Jockey Club Polyclinic

282

125

61.1

113

43.3

W-A10

Alhambra Building

286

125

65.2

111

43.2

W-A11

Hong Kong Community College (HKCC) of PolyU

278

114

62.6

113

43.6

W-A12

Civil Aid Service Headquarter

262

125

62.7

112

43.8

W-A13

Park Avenue Tower 10

245

99

49.8

112

42.4

W-A14

Charming Garden Block 1

251

103

52.4

112

42.8

W-A15

HKMA David Li Kwok Po College

251

100

52.8

112

42.7

W-P1

Reprovisioned Yau Ma Tei Police Station (Planned)

263

118

56.3

112

43.1

W-P3

West Kowloon Government Offices (Planned)

277

114

61.0

113

43.8

W-P4

Indoor Recreation Centre (Planned)

277

114

56.4

114

43.5

W-P5

Hong Kong Red Cross Headquarters (Planned)

276

110

54.0

113

43.2

W-P6

Refuse Collection Point and street Sleepers’ Shelters (Planned)

247

116

62.5

112

43.3

W-P7

Primary School (Planned)

263

120

58.9

112

43.3

W-P8

Hindu Temple (Planned)

262

122

61.5

112

43.6

Central Portion

 

 

 

 

 

M-A1

Kar Man House, Oi Man Estate

260

99

44.8

112

42.5

M-A2

Carmel on the Hill

273

96

42.3

112

42.4

M-A3

SKH Tsoi Kung Po Secondary School

275

97

46.0

112

42.6

M-A4

Man Fuk House Block A

264

97

45.1

112

42.5

M-A5

Cascades Block A

269

96

42.7

112

42.4

M-A6

Ko Fai House, Kwun Fai Court

281

97

41.0

112

42.4

M-A7

The Open University of Hong Kong

273

98

44.2

112

42.5

M-A8

Kwun Hei Court

276

92

37.8

112

42.1

M-A9

Housing Authority Headquarters Block 1

268

98

45.1

112

42.5

M-A10

Ho Man Tin Government Offices

263

96

42.7

112

42.4

M-A11

Choi Man House, Ho Man Tin Estate

275

92

38.0

112

42.1

M-A12

King Man House, Ho Man Tin Estate

280

94

39.7

112

42.2

M-A13

Ho Man Tin Swimming Pool

262

95

40.3

112

42.2

M-A14

Yee Man house

266

92

37.8

112

42.1

M-A15

Ho Man Tin Estate Service Reservoir Playground

272

94

39.2

112

42.2

M-A16

Ko Shan Road Park

267

89

32.8

110

41.0

M-A17

Kiu Wai Mansion

277

97

35.5

111

41.2

M-A18

Sun Man House

277

98

43.1

112

42.4

M-A19

Ellery Terrance

280

100

44.4

112

42.5

M-A20

Dragon View (Block 1)

278

99

45.1

112

42.5

M-P1

Valley Road Estate Redevelopment (Planned)

270

101

50.1

112

42.8

M-P2

Planned Residential Area B (Planned)

259

101

47.2

112

42.6

M-P3

Ho Man Tin South Phase 2 (Planned)

281

92

37.6

112

42.1

M-P4

Ho Man Tin Redevelopment (Outline Zoning Plan No. S/K7/21 ) (Planned)

279

92

38.8

112

42.2

M-P5

Ho Man Tin Redevelopment (KIL 11128) (Planned)

279

94

41.7

112

42.4

M-P6

Hong Kong Polytechnic University Student Hostel Phase 3 (Planned)

261

106

44.6

110

42.3

East Portion

 

 

 

 

 

E-A1

Hong Kong International Trade and Exhibition Centre

270

96

44.0

109

40.6

E-A2

EMSD Headquarters

278

93

45.3

109

40.8

E-A4

Billion Centre

262

94

49.2

107

41.1

E-A5

Kai Fuk Industrial Centre

270

101

50.3

109

41.5

E-A6

Grand Watefront

261

99

41.0

110

41.6

E-A7

Chong Chien Court

258

97

40.9

110

41.6

E-A8

Wei Chien Court

258

98

39.3

110

41.5

E-A9

Sino Industrial Plaza

277

102

45.8

110

41.0

E-A10

HSBC Main Treasury

269

96

44.4

109

40.6

E-A11

Holy Carpenter Primary School

258

96

38.3

110

41.5

E-A12

United Daily News Centre

258

96

38.3

110

41.5

E-A13

Merit Industrial Centre

258

95

53.8

110

42.4

E-A14

Wyler Gardens

258

99

39.6

110

41.5

E-P1

Site 1B4 – School (Planned)

268

84

38.8

108

40.3

E-P2

Site 1I3 – Residential (Planned)

265

81

35.1

108

40.0

E-P3

Site 1J1 (Planned)

267

87

40.1

108

40.4

E-P4

Site 1J3 (Planned)

276

83

39.4

108

40.3

E-P5

Site 1L3 - Residential (Planned)

278

87

40.6

108

40.4

E-P6

Site 1L2 - Residential (Planned)

280

94

43.5

109

40.6

E-P7

Site 2D2 – Stadium (Planned)

286

96

49.7

110

42.2

E-P8

Site 2D1 – Stadium (Planned)

261

85

35.7

107

39.9

E-P9

Site 1P – Administration Building (Planned)

266

98

53.7

107

41.2

E-P10

Site 3C1 – Hospital (Planned)

252

93

43.8

106

40.7

E-P11

Site 3C1 – Hospital (Planned)

246

97

52.2

106

41.2

E-P12

Site 3D2 – Commercial (Planned)

252

96

45.1

106

40.8

E-P13

Site 4Ab – Metro Park (Planned)

247

93

42.5

106

40.4

E-P14

Site 4Aa – Metro Park (Planned)

254

95

44.9

106

40.6

E-P15

Site 5A4a (Planned)

271

96

41.9

110

41.7

E-P16

Site 5A4b (Planned)

261

97

41.2

110

41.6

E-P17

Site 3B1- Secondary School (Planned)

255

93

43.2

106

40.5

E-P18

Site  3B1 (Planned)

252

94

44.4

106

40.6

4.4.8                  Operational Requirement for the APS

In order to maintain the performance of the APS, air pollutant sensors would be adopted in the TVS/APS to monitor the pollutant concentration levels continuously at the inlet and outlet of the system. The sensor type would be selected by the Contractor based on a performance specification. In case that the pollutant removal efficiencies were detected below the committed 80% for both particulate and NO2, as a contingency plan, immediate measures would be implemented to increase the overall contact time between the air pollutant and the APS to secure the pollutant removal rate. Simultaneously, the NO2 removal system or the ESP module will be refreshed by means of removal/replacement of the media (such as activated carbon) or washing the modules with appropriate chemical solutions, depending on the detailed design in the future. Detailed contingency plan shall be formulated by the Contractor and submitted to the Transport Department for agreement before the commencement of the proposed APS.

In addition, a commissioning test shall also be conducted by the Contractor to demonstrate the performance of the proposed APS. Details of the commissioning test shall also be submitted for agreement with the Transport Department before the commencement of the Project.

4.5                         Conclusion

Air quality impact assessment has been conducted for both construction and operational phases of CKR. Potential dust impact would be generated from the site clearance, ground excavation, construction of the associated facilities and transportation of soil during the construction phase. Quantitative fugitive dust assessments have been conducted.  Results have concluded that there will not be any adverse residual air quality impacts during construction phase given frequent watering in all works area once per hour during working hours (7:00am – 7:00pm) and provision of a dust enclosure at barging point.

Operational phase air quality assessments have concluded that the predicted air quality impacts on all sensitive receivers would comply with AQO.  The tunnel ventilation system of CKR is designed to maintain limited discharge of emission from the portals.  An air purification system (APS) will be adopted to remove the pollutant concentrations before releasing to atmosphere via the three ventilation buildings.  The current design aims to achieve a removal efficiency of 80% for particulate and 80% for NO2. It is recommended that a commissioning test shall be conducted by the Contractor to confirm the APS performance before the commencement and continuous monitoring during daily operation thereafter. In case that the performance of APS during operation could not achieve the committed removal efficiency, the procedures to be formulated by the Contractor in the contingency plan shall be followed.

4.6                         References

[4-1]                     Sun Y.,Wang L.L..,Wang Y.S. (2010) “In Situ measurements of SO2, NOx, NOy, and O3 in Beijing, China during August 2008” Science of the Total Environment 409 (2011), P933-940

[4-2]                     Sun Y.,Wang L.L..,Wang Y.S. (2010) “In situ measurements of NO, NO2, NOy, and O3 in Dinghushan (112oE, 23oN), China during autumn 2008”, Atmospheric Environment 44 (2010), P2079-2088

[4-3]                     EPD'S Air Quality in Hong Kong 2009 (http://www.epd-asg.gov.hk/english/report/files/aqr09e.pdf)

[4-4]                     Ho K.F., Lee S.C., Guo H., Tsai W.Y.(2003) “Seasonal and diurnal variations of volatile organic compounds (VOCs) in the atmosphere of Hong Kong”, Science of the Total Environment 322 (2004), P155-160